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Published: 4 June 2021
Last updated: 1 February 2022

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1

Yang, Min, Antoinette Johnson, and Timothy F. Murphy. "Characterization and Evaluation of theMoraxella catarrhalisOligopeptide Permease A as a Mucosal Vaccine Antigen." Infection and Immunity 79, no. 2 (December 6, 2010): 846–57. http://dx.doi.org/10.1128/iai.00314-10.

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ABSTRACTMoraxella catarrhalisis a common cause of otitis media in children and of lower respiratory tract infections in adults with chronic obstructive pulmonary disease; therefore, these two groups would benefit from a vaccine to preventM. catarrhalisinfections. A genome mining approach for vaccine antigens identified oligopeptide permease protein A (OppA), an oligopeptide binding protein of an apparent oligopeptide transport system. Analysis of theoppAgene by PCR and sequence analysis revealed that OppA is highly conserved among clinical isolates ofM. catarrhalis. Recombinant OppA was expressed as a lipoprotein and purified, and anoppAknockout mutant was constructed. Antiserum raised to recombinant purified OppA recognized epitopes on the bacterial surface of the wild type but not the OppA knockout mutant. Antibodies raised to purified recombinant OppA recognized native OppA in multiple strains. Intranasal immunization of mice induced systemic and mucosal antibodies to OppA and resulted in enhanced clearance ofM. catarrhalisin a mouse pulmonary clearance model. OppA is a highly conserved, immunogenic protein that expresses epitopes on the bacterial surface and that induces potentially protective immune responses in a mouse model. OppA should be evaluated further as a vaccine antigen forM. catarrhalis.
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2

Aebi, Christoph, Leslie D. Cope, Jo L. Latimer, Sharon E. Thomas, Clive A. Slaughter, George H. McCracken, and Eric J. Hansen. "Mapping of a Protective Epitope of the CopB Outer Membrane Protein of Moraxella catarrhalis." Infection and Immunity 66, no. 2 (February 1, 1998): 540–48. http://dx.doi.org/10.1128/iai.66.2.540-548.1998.

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ABSTRACT A monoclonal antibody (MAb) (MAb 10F3) directed against the CopB outer membrane protein of Moraxella catarrhalis previously was found to enhance pulmonary clearance of M. catarrhalisin an animal model (M. Helminen, I. Maciver, J. L. Latimer, L. D. Cope, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 61:2003–2010, 1993). In the present study, this same MAb was shown to exert complement-dependent bactericidal activity against this pathogen in vitro. Nucleotide sequence analysis of thecopB gene from two MAb 10F3-reactive and two MAb 10F3-unreactive strains of M. catarrhalis revealed that the deduced amino acid sequences of these four CopB proteins were at least 90% identical. Comparison of the amino acid sequences of these proteins allowed localization of possible MAb 10F3 binding sites to five relatively small regions of the CopB protein from M. catarrhalis O35E. When five synthetic peptides representing these regions were tested for their ability to bind MAb 10F3 in a direct enzyme-linked immunosorbent assay system, an oligopeptide containing 26 amino acids was shown to bind this MAb. The actual binding region for MAb 10F3 was localized further through the use of overlapping decapeptides that spanned this 26-mer. A fusion protein containing the same 26-mer readily bound MAb 10F3 and was used to immunize mice. The resultant antiserum contained antibodies that reacted with the CopB protein of the homologous M. catarrhalis strain in Western blot analysis and bound to the surface of both homologous and heterologous strains of M. catarrhalis.
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3

Riou, J. Y., and M. Guibourdenche. "Branhamella catarrhalis." Drugs 31, Supplement 3 (1986): 1–6. http://dx.doi.org/10.2165/00003495-198600313-00003.

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4

SHEFF, BARBARA. "Moraxella Catarrhalis." Nursing 33, no. 1 (January 2003): 81. http://dx.doi.org/10.1097/00152193-200301000-00055.

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5

Otsuka, Taketo, Charmaine Kirkham, Aimee Brauer, Mary Koszelak-Rosenblum, Michael G. Malkowski, and Timothy F. Murphy. "The Vaccine Candidate Substrate Binding Protein SBP2 Plays a Key Role in Arginine Uptake, Which Is Required for Growth of Moraxella catarrhalis." Infection and Immunity 84, no. 2 (November 23, 2015): 432–38. http://dx.doi.org/10.1128/iai.00799-15.

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Moraxella catarrhalisis an exclusively human pathogen that is an important cause of otitis media in children and lower respiratory tract infections in adults with chronic obstructive pulmonary disease. A vaccine to preventM. catarrhalisinfections would have an enormous global impact in reducing morbidity resulting from these infections. Substrate binding protein 2 (SBP2) of an ABC transporter system has recently been identified as a promising vaccine candidate antigen on the bacterial surface ofM. catarrhalis. In this study, we showed that SBP1, -2, and -3 individually bind different basic amino acids with exquisite specificity. We engineered mutants that each expressed a single SBP from this gene cluster and showed in growth experiments that SBP1, -2, and -3 serve a nutritional function through acquisition of amino acids for the bacterium. SBP2 mediates uptake of arginine, a strict growth requirement ofM. catarrhalis. Adherence and invasion assays demonstrated that SBP1 and SBP3 play a role in invasion of human respiratory epithelial cells, consistent with a nutritional role in intracellular survival in the human respiratory tract. This work demonstrates that the SBPs of an ABC transporter system function in the uptake of basic amino acids to support growth ofM. catarrhalis. The critical role of SBP2 in arginine uptake may contribute to its potential as a vaccine antigen.
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6

Sano, Naoto, Satoshi Matsunaga, Tomonori Akiyama, Yukari Nakashima, Koji Kusaba, Zenzo Nagasawa, Shunzo Koizumi, Masaaki Goto, and Hiroshi Miyamoto. "Moraxella catarrhalis bacteraemia associated with prosthetic vascular graft infection." Journal of Medical Microbiology 59, no. 2 (February 1, 2010): 245–50. http://dx.doi.org/10.1099/jmm.0.013789-0.

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Moraxella catarrhalis, formerly called Branhamella catarrhalis, ‘Neisseria catarrhalis’ or ‘Micrococcus catarrhalis’, is a Gram-negative, aerobic diplococcus frequently found as a colonizer of the upper respiratory tract. Over the last 20–30 years, this bacterium has emerged as a genuine pathogen, and is now considered an important cause of otitis media in children and an aetiological agent in pneumonia in adults with chronic obstructive pulmonary disease. However, bacteraemia due to M. catarrhalis has rarely been reported. Presented here is a case of M. catarrhalis bacteraemia associated with prosthetic vascular graft infection along with a review of the relevant literature.
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7

Slevogt, Hortense, Bernd Schmeck, Carola Jonatat, Janine Zahlten, Wiebke Beermann, Vincent van Laak, Bastian Opitz, et al. "Moraxella catarrhalis induces inflammatory response of bronchial epithelial cells via MAPK and NF-κB activation and histone deacetylase activity reduction." American Journal of Physiology-Lung Cellular and Molecular Physiology 290, no. 5 (May 2006): L818—L826. http://dx.doi.org/10.1152/ajplung.00428.2005.

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Moraxella catarrhalis is a major cause of infectious exacerbations of chronic obstructive lung disease (COPD) and may also contribute to the pathogenesis of COPD. Little is known about M. catarrhalis-bronchial epithelium interaction. We investigated activation of M. catarrhalis infected bronchial epithelial cells and characterized the signal transduction pathways. Moreover, we tested the hypothesis that the M. catarrhalis-induced cytokine expression is regulated by acetylation of histone residues and controlled by histone deacetylase activity (HDAC). We demonstrated that M. catarrhalis induced a strong time- and dose-dependent inflammatory response in the bronchial epithelial cell line (BEAS-2B), characterized by the release of IL-8 and GM-CSF. For this cytokine liberation activation of the ERK and p38 mitogen-activated protein (MAP) kinases and transcription factor NF-κB was required. Furthermore, M. catarrhalis-infected bronchial epithelial cells showed an enhanced acetylation of histone H3 and H4 globally and at the promoter of the il8 gene. Preventing histone deacetylation by the histone deacetylase inhibitor trichostatin A augmented the M. catarrhalis-induced IL-8 response. After exposure to M. catarrhalis, we found a decrease in global histone deacetylase expression and activity. Our findings suggest that M. catarrhalis-induced activation of il8 gene transcription was caused by interference with epigenetic mechanisms regulating il8 gene accessibility. Our findings provide insight into important molecular and cellular mechanisms of M. catarrhalis-induced activation of human bronchial epithelium.
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8

Igic, Marija, Ljiljana Kesic, Radmila Obradovic, Gordana Filipovic, Branislava Stojkovic, and Kosta Todorovic. "Comparative clinical evaluation of the therapeutic effects of low-level laser and hyaluronic acid on gingivitis catarrhalis in children." Vojnosanitetski pregled 77, no. 7 (2020): 736–39. http://dx.doi.org/10.2298/vsp171207118i.

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Background/Aim. Gingivitis catarrhalis is the most common disease of the oral mucosa in children, representing an inflammation of the gingiva of an exudative nature. The aim of this study was to evaluate the effectiveness of low-level laser therapy and hyaluronic acid therapy on gingivitis catarrhalis in children using the appropriate clinical parameters. Methods. The study involved 100 children with permanent dentition in whom gingivitis catarrhalis had been diagnosed. The examinees were divided into two groups: the group I consisting of patients with gingival inflammation (50 examinees) in whom the therapy with hyaluronic acid was applied after the removal of soft and hard dental deposits, and the group II consisting of patients with gingival inflammation (50 examinees) in whom low-level laser therapy was applied after the removal of soft and hard dental deposits. Clinical evaluation of the therapeutic effects of low-level laser and hyaluronic acid on gingivitis catarrhalis was performed using the appropriate indices: the Greene-Vermillion Plaque Index (PI), Muhlemann bleeding index (BI), and Community Periodontal Index of Treatment Needs (CPITN). Results. Using the Student?s t-test for dependent samples, a statistically significant difference was obtained (p < 0.001) between the PI, BI, and CPITN indices before and after the therapy in both examined groups. Moreover, the CPITN index after the therapy in the group II was statistically significantly lower (p < 0.05) than that obtained in the group I. Conclusion. The results demonstrated an exceptional effect of hyaluronic acid and low-level laser therapy, supplementing basic therapy, in the treatment of catarrhal gingivitis in children. Somewhat better results were achieved with the combination of basic therapy and low-level laser.
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9

Gutbier, Birgitt, Katja Fischer, Jan-Moritz Doehn, Carolin von Lachner, Christian Herr, Esther Klaile, Ursula Frischmann, et al. "Moraxella catarrhalisinduces an immune response in the murine lung that is independent of human CEACAM5 expression and long-term smoke exposure." American Journal of Physiology-Lung Cellular and Molecular Physiology 309, no. 3 (August 1, 2015): L250—L261. http://dx.doi.org/10.1152/ajplung.00265.2014.

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In patients with chronic obstructive pulmonary disease (COPD), Moraxella catarrhalis infection of the lower airways is associated with chronic colonization and inflammation during stable disease and acute exacerbations. Chronic smoke exposure induces chronic inflammation and impairs mucociliary clearance, thus contributing to bacterial colonization of the lower airways in COPD patients. The human-specific carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 5, expressed in human airways, has been shown to contribute to epithelial colonization of CEACAM-binding pathogens. To investigate the impact of CEACAM5 expression on pulmonary M. catarrhalis colonization, we infected mice transgenic for human CEACAM5 (hCEACAM5) and wild type mice intratracheally with M. catarrhalis with or without preceding smoke exposure and analyzed bacterial colonization and local and systemic inflammation. Our results show that airway infection with M. catarrhalis accelerated acute local but not systemic inflammation, albeit independent of hCEACAM5 expression. Long-term smoke exposure alone or prior to M. catarrhalis infection did not contribute to increased local or systemic inflammation. No difference was found in pulmonary clearance of M. catarrhalis in hCEACAM5-transgenic mice compared with wild-type mice. Smoke exposure neither altered time nor extent of persistence of M. catarrhalis in the lungs of both genotypes. In conclusion, M. catarrhalis induced a local acute immune response in murine airways. Neither hCEACAM5 expression nor chronic smoke exposure nor a combination of both was sufficient as prerequisites for the establishment of chronic M. catarrhalis colonization. Our results demonstrate the difficulties in mirroring conditions of chronic airways colonization of M. catarrhalis in a murine model.
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10

Luke, Nicole R., Joseph A. Jurcisek, Lauren O. Bakaletz, and Anthony A. Campagnari. "Contribution of Moraxella catarrhalis Type IV Pili to Nasopharyngeal Colonization and Biofilm Formation." Infection and Immunity 75, no. 12 (October 1, 2007): 5559–64. http://dx.doi.org/10.1128/iai.00946-07.

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ABSTRACT Moraxella catarrhalis is a gram-negative mucosal pathogen of the human respiratory tract. Although little information is available regarding the initial steps of M. catarrhalis pathogenesis, this organism must be able to colonize the human mucosal surface in order to initiate an infection. Type IV pili (TFP), filamentous surface appendages primarily comprised of a single protein subunit termed pilin, play a crucial role in the initiation of disease by a wide range of bacteria. We previously identified the genes that encode the major proteins involved in the biosynthesis of M. catarrhalis TFP and determined that the TFP expressed by this organism are highly conserved and essential for natural transformation. We extended this initial study by investigating the contribution of TFP to the early stages of M. catarrhalis colonization. TFP-deficient M. catarrhalis bacteria exhibit diminished adherence to eukaryotic cells in vitro. Additionally, our studies demonstrate that M. catarrhalis cells form a mature biofilm in continuous-flow chambers and that biofilm formation is enhanced by TFP expression. The potential role of TFP in colonization by M. catarrhalis was further investigated using in vivo studies comparing the abilities of wild-type M. catarrhalis and an isogenic TFP mutant to colonize the nasopharynx of the chinchilla. These results suggest that the expression of TFP contributes to mucosal airway colonization. Furthermore, these data indicate that the chinchilla model of nasopharyngeal colonization provides an effective animal system for studying the early steps of M. catarrhalis pathogenesis.
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11

Lierde, Stefaan Van, Jennifer M. Puck, Joseph M. Campos, and Stanley A. Plotkin. "BRANHAMELLA CATARRHALIS SEPSIS." Pediatric Infectious Disease Journal 4, no. 5 (September 1985): 562. http://dx.doi.org/10.1097/00006454-198509000-00031.

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12

Chan, Daisy. "MORAXELLA CATARRHALIS KERATOCONJUNCTIVITIS." Optometry and Vision Science 78, SUPPLEMENT (December 2001): 186. http://dx.doi.org/10.1097/00006324-200112001-00305.

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13

Garcia-Garrote, Fernando, Ana Menasalvas, Luciá Martínez-Sánchez, Emilia Cercenado, Luis Alcalá, and Emilio Bouza. "Moraxella catarrhalis bacteremia." Clinical Microbiology Newsletter 19, no. 23 (December 1997): 183–84. http://dx.doi.org/10.1016/s0196-4399(00)89191-6.

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14

Sadjadi, Seyed-Ali, Paz Obedoza, and Pawan Annamarju. "Moraxella Catarrhalis peritonitis." American Journal of Case Reports 13 (2012): 19–21. http://dx.doi.org/10.12659/ajcr.882358.

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15

Heidemann, David G., Eduardo Alfonso, Richard K. Forster, Saul Ullman, Simon P. Holland, Alan Mendelsohn, and Darlene Miller. "Branhamella catarrhalis Keratitis." American Journal of Ophthalmology 103, no. 4 (April 1987): 576–81. http://dx.doi.org/10.1016/s0002-9394(14)74282-5.

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16

ROMBERGER, JAMES A., ELLEN R. WALD, and PETER F. WRIGHT. "Branhamella catarrhalis Conjunctivitis." Southern Medical Journal 80, no. 7 (July 1987): 926–28. http://dx.doi.org/10.1097/00007611-198707000-00032.

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17

Verghese, Abraham, and Steven L. Berk. "Moraxella (Branhamella) catarrhalis." Infectious Disease Clinics of North America 5, no. 3 (September 1991): 523–38. http://dx.doi.org/10.1016/s0891-5520(20)30404-9.

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18

Attia, Ahmed S., Jennifer L. Sedillo, Wei Wang, Wei Liu, Chad A. Brautigam, Wade Winkler, and Eric J. Hansen. "Moraxella catarrhalis Expresses an Unusual Hfq Protein." Infection and Immunity 76, no. 6 (March 24, 2008): 2520–30. http://dx.doi.org/10.1128/iai.01652-07.

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ABSTRACT The Hfq protein is recognized as a global regulatory molecule that facilitates certain RNA-RNA interactions in bacteria. BLAST analysis identified a 630-nucleotide open reading frame in the genome of Moraxella catarrhalis ATCC 43617 that was highly conserved among M. catarrhalis strains and which encoded a predicted protein with significant homology to the Hfq protein of Escherichia coli. This protein, containing 210 amino acids, was more than twice as large as the Hfq proteins previously described for other bacteria. The C-terminal half of the M. catarrhalis Hfq protein was very hydrophilic and contained two different types of amino acid repeats. A mutation in the M. catarrhalis hfq gene affected both the growth rate of this organism and its sensitivity to at least two different types of stress in vitro. Provision of the wild-type M. catarrhalis hfq gene in trans eliminated these phenotypic differences in the hfq mutant. This M. catarrhalis hfq mutant exhibited altered expression of some cell envelope proteins relative to the wild-type parent strain and also had a growth advantage in a continuous flow biofilm system. The presence of the wild-type M. catarrhalis hfq gene in trans in an E. coli hfq mutant fully reversed the modest growth deficiency of this E. coli mutant and partially reversed the stress sensitivity of this E. coli mutant to methyl viologen. The use of an electrophoretic mobility shift assay showed that this M. catarrhalis Hfq protein could bind RNA derived from a gene whose expression was altered in the M. catarrhalis hfq mutant.
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19

Verduin, Cees M., Cees Hol, André Fleer, Hans van Dijk, and Alex van Belkum. "Moraxella catarrhalis: from Emerging to Established Pathogen." Clinical Microbiology Reviews 15, no. 1 (January 2002): 125–44. http://dx.doi.org/10.1128/cmr.15.1.125-144.2002.

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SUMMARY Moraxella catarrhalis (formerly known as Branhamella catarrhalis) has emerged as a significant bacterial pathogen of humans over the past two decades. During this period, microbiological and molecular diagnostic techniques have been developed and improved for M. catarrhalis, allowing the adequate determination and taxonomic positioning of this pathogen. Over the same period, studies have revealed its involvement in respiratory (e.g., sinusitis, otitis media, bronchitis, and pneumonia) and ocular infections in children and in laryngitis, bronchitis, and pneumonia in adults. The development of (molecular) epidemiological tools has enabled the national and international distribution of M. catarrhalis strains to be established, and has allowed the monitoring of nosocomial infections and the dynamics of carriage. Indeed, such monitoring has revealed an increasing number of Β-lactamase-positive M. catarrhalis isolates (now well above 90%), underscoring the pathogenic potential of this organism. Although a number of putative M. catarrhalis virulence factors have been identified and described in detail, their relationship to actual bacterial adhesion, invasion, complement resistance, etc. (and ultimately their role in infection and immunity), has been established in a only few cases. In the past 10 years, various animal models for the study of M. catarrhalis pathogenicity have been described, although not all of these models are equally suitable for the study of human infection. Techniques involving the molecular manipulation of M. catarrhalis genes and antigens are also advancing our knowledge of the host response to and pathogenesis of this bacterial species in humans, as well as providing insights into possible vaccine candidates. This review aims to outline our current knowledge of M. catarrhalis, an organism that has evolved from an emerging to a well-established human pathogen.
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20

Hoopman, Todd C., Wei Wang, Chad A. Brautigam, Jennifer L. Sedillo, Thomas J. Reilly, and Eric J. Hansen. "Moraxella catarrhalis Synthesizes an Autotransporter That Is an Acid Phosphatase." Journal of Bacteriology 190, no. 4 (December 7, 2007): 1459–72. http://dx.doi.org/10.1128/jb.01688-07.

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ABSTRACT Moraxella catarrhalis O35E was shown to synthesize a 105-kDa protein that has similarity to both acid phosphatases and autotransporters. The N-terminal portion of the M. catarrhalis acid phosphatase A (MapA) was most similar (the BLAST probability score was 10−10) to bacterial class A nonspecific acid phosphatases. The central region of the MapA protein had similarity to passenger domains of other autotransporter proteins, whereas the C-terminal portion of MapA resembled the translocation domain of conventional autotransporters. Cloning and expression of the M. catarrhalis mapA gene in Escherichia coli confirmed the presence of acid phosphatase activity in the MapA protein. The MapA protein was shown to be localized to the outer membrane of M. catarrhalis and was not detected either in the soluble cytoplasmic fraction from disrupted M. catarrhalis cells or in the spent culture supernatant fluid from M. catarrhalis. Use of the predicted MapA translocation domain in a fusion construct with the passenger domain from another predicted M. catarrhalis autotransporter confirmed the translocation ability of this MapA domain. Inactivation of the mapA gene in M. catarrhalis strain O35E reduced the acid phosphatase activity expressed by this organism, and this mutation could be complemented in trans with the wild-type mapA gene. Nucleotide sequence analysis of the mapA gene from six M. catarrhalis strains showed that this protein was highly conserved among strains of this pathogen. Site-directed mutagenesis of a critical histidine residue (H233A) in the predicted active site of the acid phosphatase domain in MapA eliminated acid phosphatase activity in the recombinant MapA protein. This is the first description of an autotransporter protein that expresses acid phosphatase activity.
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21

Verhaegh, Suzanne J. C., Martine L. Snippe, Foster Levy, Henri A. Verbrugh, Vincent W. V. Jaddoe, Albert Hofman, Henriëtte A. Moll, Alex van Belkum, and John P. Hays. "Colonization of healthy children by Moraxella catarrhalis is characterized by genotype heterogeneity, virulence gene diversity and co-colonization with Haemophilus influenzae." Microbiology 157, no. 1 (January 1, 2011): 169–78. http://dx.doi.org/10.1099/mic.0.042929-0.

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The colonization dynamics of Moraxella catarrhalis were studied in a population comprising 1079 healthy children living in Rotterdam, The Netherlands (the Generation R Focus cohort). A total of 2751 nasal swabs were obtained during four clinic visits timed to take place at 1.5, 6, 14 and 24 months of age, yielding a total of 709 M. catarrhalis and 621 Haemophilus influenzae isolates. Between January 2004 and December 2006, approximate but regular 6-monthly cycles of colonization were observed, with peak colonization incidences occurring in the autumn/winter for M. catarrhalis, and winter/spring for H. influenzae. Co-colonization was significantly more likely than single-species colonization with either M. catarrhalis or H. influenzae, with genotypic analysis revealing no clonality for co-colonizing or single colonizers of either bacterial species. This finding is especially relevant considering the recent discovery of the importance of H. influenzae–M. catarrhalis quorum sensing in biofilm formation and host clearance. Bacterial genotype heterogeneity was maintained over the 3-year period of the study, even within this relatively localized geographical region, and there was no association of genotypes with either season or year of isolation. Furthermore, chronological and genotypic diversity in three immunologically important M. catarrhalis virulence genes (uspA1, uspA2 and hag/mid) was also observed. This study indicates that genotypic variation is a key factor contributing to the success of M. catarrhalis colonization of healthy children in the first years of life. Furthermore, variation in immunologically relevant virulence genes within colonizing populations, and even within genotypically identical M. catarrhalis isolates, may be a result of immune evasion by this pathogen. Finally, the factors facilitating M. catarrhalis and H. influenzae co-colonization need to be further investigated.
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22

Otsuka, Taketo, Charmaine Kirkham, Antoinette Johnson, Megan M. Jones, and Timothy F. Murphy. "Substrate Binding Protein SBP2 of a Putative ABC Transporter as a Novel Vaccine Antigen of Moraxella catarrhalis." Infection and Immunity 82, no. 8 (June 9, 2014): 3503–12. http://dx.doi.org/10.1128/iai.01832-14.

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ABSTRACTMoraxella catarrhalisis a common respiratory tract pathogen that causes otitis media in children and infections in adults with chronic obstructive pulmonary disease. Since the introduction of the pneumococcal conjugate vaccines with/without protein D of nontypeableHaemophilus influenzae,M. catarrhalishas become a high-priority pathogen in otitis media. For the development of antibacterial vaccines and therapies, substrate binding proteins of ATP-binding cassette transporters are important targets. In this study, we identified and characterized a substrate binding protein, SBP2, ofM. catarrhalis. Among 30 clinical isolates tested, thesbp2gene sequence was highly conserved. In 2 different analyses (whole-cell enzyme-linked immunosorbent assay and flow cytometry), polyclonal antibodies raised to recombinant SBP2 demonstrated that SBP2 expresses epitopes on the bacterial surface of the wild type but not thesbp2mutant. Mice immunized with recombinant SBP2 showed significantly enhanced clearance ofM. catarrhalisfrom the lung compared to that in the control group at both 25-μg and 50-μg doses (P< 0.001). We conclude that SBP2 is a novel, attractive candidate as a vaccine antigen againstM. catarrhalis.
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23

Zaleski, Anthony, N. Karoline Scheffler, Peter Densen, Frank K. N. Lee, Anthony A. Campagnari, Bradford W. Gibson, and Michael A. Apicella. "Lipooligosaccharide Pk(Galα1-4Galβ1-4Glc) Epitope of Moraxella catarrhalis Is a Factor in Resistance to Bactericidal Activity Mediated by Normal Human Serum." Infection and Immunity 68, no. 9 (September 1, 2000): 5261–68. http://dx.doi.org/10.1128/iai.68.9.5261-5268.2000.

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ABSTRACT Moraxella catarrhalis is a respiratory pathogen responsible for acute bacterial otitis media in children and exacerbation of chronic bronchitis in adults. M. catarrhalis strains are frequently resistant to the bactericidal activity of normal human serum. In order to determine if the lipooligosaccharide (LOS) of M. catarrhalis has a role in serum resistance, the UDP-glucose-4-epimerase (galE) gene was identified, cloned, and sequenced and a deletion/insertion mutation was introduced into M. catarrhalis strain 2951. GalE enzymatic activity, measured in whole-cell lysates, was ablated inM. catarrhalis 2951 galE. Mass spectrometric analysis of LOS isolated with hot phenol-water confirmed that strain 2951 produced a type A LOS. These studies showed that the LOS from 2951galE had lost two hexose residues due to thegalE mutation and that the resultant LOS structure lacked the (Galα1-4Galβ1-4Glc) Pk epitope found onM. catarrhalis 2951. Wild-type M. catarrhalis2951 is resistant to complement-mediated serum bactericidal activity. In contrast, a greater than 2-log10-unit reduction in CFU occurred after incubation of 2951 galE in either 50 or 25% pooled human serum (PNHS), and CFU in 10% PNHS decreased by about 1 log10 unit. These studies suggest that the Pkepitope of the LOS may be an important factor in the resistance of M. catarrhalis to the complement-mediated bactericidal effect of normal human serum.
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24

Furano, Kristin, and Anthony A. Campagnari. "Identification of a Hemin Utilization Protein of Moraxella catarrhalis (HumA)." Infection and Immunity 72, no. 11 (November 2004): 6426–32. http://dx.doi.org/10.1128/iai.72.11.6426-6432.2004.

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ABSTRACT Moraxella catarrhalis is a major cause of acute otitis media in young children and has also been implicated as an important cause of exacerbations in adults with underlying pulmonary disease. Due to the considerable level of antibiotic resistance and the high degree of carriage rates in young children, it is likely that the incidence of M. catarrhalis infections will continue to rise. M. catarrhalis is a strict human respiratory pathogen, and this bacterium uses both transferrin and lactoferrin receptors to fulfill the essential iron requirement for survival in vivo. However, these are the only described iron acquisition systems for this organism. In this report we have demonstrated that M. catarrhalis can also utilize hemin as a sole source of iron for growth. In addition, we have identified and characterized an outer membrane protein with homology (26 to 28% similarity) to other known hemin binding and uptake proteins in related gram-negative organisms (i.e., Bordetella and Yersinia spp.). This newly described M. catarrhalis protein, termed HumA, is capable of directly binding to hemin coupled to a solid-phase matrix. M. catarrhalis HumA expressed on the surface of an Escherichia coli hemA-deficient strain (K-12 EB53) is fully capable of complementing the defect and thus restoring the ability of this strain to grow in the presence of hemin. When M. catarrhalis is grown in the presence of hemin, HumA expression is clearly increased as shown by Western blotting with polyclonal antiserum developed against a HumA peptide. In addition, growth analyses revealed that a HumA-deficient mutant of M. catarrhalis (7169::humA) is restricted for growth in the presence of hemin as the sole iron source compared to the wild-type strain. We conclude that HumA is an essential component of a hemin uptake and utilization system previously undescribed for M. catarrhalis, thus providing another mechanism of iron acquisition that may facilitate persistent colonization of the mucosal surface.
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Bootsma, H. J., H. van Dijk, J. Verhoef, A. Fleer, and F. R. Mooi. "Molecular characterization of the BRO beta-lactamase of Moraxella (Branhamella) catarrhalis." Antimicrobial Agents and Chemotherapy 40, no. 4 (April 1996): 966–72. http://dx.doi.org/10.1128/aac.40.4.966.

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A rapid increase in the prevalence of beta-lactamase-producing Moraxella (Branhamella) catarrhalis strains has been noticed during the last decades. Today, more than 80% of strains isolated worldwide produce beta-lactamase. To investigate beta-lactamase(s) of M. catarrhalis at the molecular level, the BRO-1 beta-lactamase gene (bla) was isolated as part of a 4,223-bp HindIII fragment. Sequence analysis indicated that bla encodes a polypeptide of 314 amino acid residues. Insertional inactivation of bla in M. catarrhalis resulted in complete abrogation of beta-lactamase production and ampicillin resistance, demonstrating that bla is solely responsible for beta-lactam resistance. Comparison with other beta-lactamases suggested that M. catarrhalis beta-lactamase is a unique enzyme with conserved residues at the active sites. The presence of a signal sequence for lipoproteins suggested that it is lipid modified at its N terminus. In keeping with this assumption was the observation that 10% of beta-lactamase activity was found in the membrane compartment of M. catarrhalis. M. catarrhalis strains produce two types of beta-lactamase, BRO-1 and BRO-2, which differ in their isoelectric points. The BRO-1 and BRO-2 genes from two ATCC strains of M. catarrhalis were sequenced, and only one amino acid difference was found between the predicted products. However, there was a 21-bp deletion in the promoter region of the BRO-2 gene, possibly explaining the lower level of production of BRO-2. The G + C content of bla (31%) was significantly lower than those of the flanking genes (47 and 50%), and the overall G + C content of the M. catarrhalis genome (41%). These results indicate that bla was acquired by horizontal gene transfer from another, still unknown species.
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de Vries, Stefan P. W., Hester J. Bootsma, John P. Hays, and Peter W. M. Hermans. "Molecular Aspects of Moraxella catarrhalis Pathogenesis." Microbiology and Molecular Biology Reviews 73, no. 3 (September 2009): 389–406. http://dx.doi.org/10.1128/mmbr.00007-09.

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SUMMARY In recent years, Moraxella catarrhalis has established its position as an important human mucosal pathogen, no longer being regarded as just a commensal bacterium. Further, current research in the field has led to a better understanding of the molecular mechanisms involved in M. catarrhalis pathogenesis, including mechanisms associated with cellular adherence, target cell invasion, modulation of the host's immune response, and metabolism. Additionally, in order to be successful in the host, M. catarrhalis has to be able to interact and compete with the commensal flora and overcome stressful environmental conditions, such as nutrient limitation. In this review, we provide a timely overview of the current understanding of the molecular mechanisms associated with M. catarrhalis virulence and pathogenesis.
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27

Luke, Nicole R., Amy J. Howlett, Jianqiang Shao, and Anthony A. Campagnari. "Expression of Type IV Pili by Moraxella catarrhalis Is Essential for Natural Competence and Is Affected by Iron Limitation." Infection and Immunity 72, no. 11 (November 2004): 6262–70. http://dx.doi.org/10.1128/iai.72.11.6262-6270.2004.

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ABSTRACT Type IV pili, filamentous surface appendages primarily composed of a single protein subunit termed pilin, play a crucial role in the initiation of disease by a wide range of pathogenic bacteria. Although previous electron microscopic studies suggested that pili might be present on the surface of Moraxella catarrhalis isolates, detailed molecular and phenotypic analyses of these structures have not been reported to date. We identified and cloned the M. catarrhalis genes encoding PilA, the major pilin subunit, PilQ, the outer membrane secretin through which the pilus filament is extruded, and PilT, the NTPase that mediates pilin disassembly and retraction. To initiate investigation of the role of this surface organelle in pathogenesis, isogenic pilA, pilT, and pilQ mutants were constructed in M. catarrhalis strain 7169. Comparative analyses of the wild-type 7169 strain and three isogenic pil mutants demonstrated that M. catarrhalis expresses type IV pili that are essential for natural genetic transformation. Our studies suggest type IV pilus production by M. catarrhalis is constitutive and ubiquitous, although pilin expression was demonstrated to be iron responsive and Fur regulated. These data indicate that additional studies aimed at elucidating the prevalence and role of type IV pili in the pathogenesis and host response to M. catarrhalis infections are warranted.
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28

Paykel, Jacquelyn M. "Moraxella (branhamella) catarrhalis infections." Primary Care Update for OB/GYNS 9, no. 1 (January 2002): 33–35. http://dx.doi.org/10.1016/s1068-607x(01)00099-3.

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29

Davies, B. I., and F. P. V. Maesen. "BRANHAMELLA CATARRHALIS CHEST INFECTIONS." Lancet 328, no. 8501 (August 1986): 278. http://dx.doi.org/10.1016/s0140-6736(86)92088-x.

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30

McMichael, John C. "Vaccines for Moraxella catarrhalis." Vaccine 19 (December 2000): S101—S107. http://dx.doi.org/10.1016/s0264-410x(00)00287-5.

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31

Pugliese, Gina, and Martin S. Favero. "Nosocomial Pathogen: Moraxella catarrhalis." Infection Control & Hospital Epidemiology 23, no. 2 (February 2002): 112. http://dx.doi.org/10.1017/s0195941700084368.

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32

Ren, Dabin, and Michael E. Pichichero. "Vaccine targets againstMoraxella catarrhalis." Expert Opinion on Therapeutic Targets 20, no. 1 (August 26, 2015): 19–33. http://dx.doi.org/10.1517/14728222.2015.1081686.

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33

Hager, H., A. Verghese, S. Alvarez, and S. L. Berk. "Branhamella catarrhalis Respiratory Infections." Clinical Infectious Diseases 9, no. 6 (November 1, 1987): 1140–49. http://dx.doi.org/10.1093/clinids/9.6.1140.

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34

Wallace, Mark R. "Moraxella (Branhamella) catarrhalis Bacteremia." Archives of Internal Medicine 150, no. 6 (June 1, 1990): 1332. http://dx.doi.org/10.1001/archinte.1990.00390180136025.

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35

Bergren, Robert L. "Branhamella (Moraxella) catarrhalis Endophthalmitis." Archives of Ophthalmology 111, no. 9 (September 1, 1993): 1169. http://dx.doi.org/10.1001/archopht.1993.01090090021009.

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36

Anezaki, Hiroki, Norihiko Terada, Takahisa Kawamura, and Hanako Kurai. "Moraxella catarrhalis bacteremic pneumonia." IDCases 19 (2020): e00712. http://dx.doi.org/10.1016/j.idcr.2020.e00712.

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37

Doern, Gary V. "Branhamella catarrhalis: Phenotypic characteristics." American Journal of Medicine 88, no. 5 (May 1990): S33—S35. http://dx.doi.org/10.1016/0002-9343(90)90259-g.

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38

Kobayashi, Yoshio. "Bacteremic Moraxella catarrhalis pneumonia." Journal of Infection and Chemotherapy 6, no. 1 (2000): 68. http://dx.doi.org/10.1007/s101560050054.

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39

Dragas, Ana Zlata, and Maria Gubina. "Methicillin-resistant Branhamella catarrhalis." Journal of Hospital Infection 7, no. 3 (May 1986): 308–9. http://dx.doi.org/10.1016/0195-6701(86)90091-5.

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40

Furano, Kristin, and Anthony A. Campagnari. "Inactivation of the Moraxella catarrhalis 7169 Ferric Uptake Regulator Increases Susceptibility to the Bactericidal Activity of Normal Human Sera." Infection and Immunity 71, no. 4 (April 2003): 1843–48. http://dx.doi.org/10.1128/iai.71.4.1843-1848.2003.

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ABSTRACT Moraxella catarrhalis is a strict human pathogen and a significant cause of respiratory disease and otitis media. In direct response to these infections, research efforts have focused primarily on the identification of potential vaccine targets. The general biology of M. catarrhalis, however, including the mechanisms utilized to survive in the human host, remains poorly understood. Previous work has demonstrated that M. catarrhalis expresses iron-repressible proteins, suggesting the presence of iron acquisition systems under the control of a ferric uptake regulator (Fur). In this study M. catarrhalis fur has been cloned and sequenced from strain 7169. A deletion-insertion mutation of 7169 fur resulted in upregulation of iron-repressible outer membrane proteins in the absence and presence of iron. This mutant strain, 7169fur1, was significantly more sensitive to the bactericidal activity of normal human serum than the resistant wild-type strain. These data suggest that constitutive expression of iron-regulated proteins may provide multiple targets for human antibodies. In addition, the 7169 fur mutant provides an important tool for further investigation of the iron acquisition mechanisms utilized by M. catarrhalis.
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41

Aiswariya, Alex, Kundoly Velayudhan Suseela, and Das Subi. "Prevalence of Moraxella catarrhalis in patients of lower respiratory tract infection with underlying risk factors." International Journal of Advances in Medicine 4, no. 2 (March 23, 2017): 442. http://dx.doi.org/10.18203/2349-3933.ijam20171038.

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Background: Moraxella catarrhalis is a Gram-negative diplococcus, commonly found as a normal flora in the human upper respiratory tract. Recently, M. catarrhalis has emerged as an important and common human respiratory tract pathogen. This study was aimed to determine the rate of isolation of M. Catarrhalis in patients attending a tertiary care hospital with lower respiratory tract infection (LRTI), antibiotic susceptibility pattern and predisposing factors responsible for their infection.Methods: A prospective study was carried out in 1001 lower respiratory specimens from patients (above 20 years’ age) with suspected LRTI. The study investigated by microscopic examination, culture and antibiotic sensitivity test according to the standard guidelines. Assessment of clinical significance of M. Catarrhalis was ascertained on the basis of preformed criteria.Results: A total of 60 clinically significant M. Catarrhalis were isolated from the 930 culture positive samples. The isolates showed maximum sensitivity to second and third generation cephalosporins (95%), azithromycin (90%) followed by amoxicillin clavulanic acid (85%). Rate of isolation was more in males (70%) and elderly people above 60 years (63.33%) were found to be more affected. Patients (58.33%) with Chronic Obstructive Pulmonary Diseases (COPD) were found to be more prone to get infection by M. Catarrhalis.Conclusions: Moraxella catarrhalis should be considered as significant lower respiratory tract pathogen especially in elderly patients with underlying risk factors like COPD.
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42

Ruckdeschel, Elizabeth A., Charmaine Kirkham, Alan J. Lesse, Zihua Hu, and Timothy F. Murphy. "Mining the Moraxella catarrhalis Genome: Identification of Potential Vaccine Antigens Expressed during Human Infection." Infection and Immunity 76, no. 4 (January 28, 2008): 1599–607. http://dx.doi.org/10.1128/iai.01253-07.

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ABSTRACT Moraxella catarrhalis is an important cause of respiratory infections in adults and otitis media in children. Developing an effective vaccine would reduce the morbidity, mortality, and costs associated with such infections. An unfinished genome sequence of a strain of M. catarrhalis available in the GenBank database was analyzed, and open reading frames predicted to encode potential vaccine candidates were identified. Three genes encoding proteins having molecular masses of approximately 22, 75, and 78 kDa (designated Msp [Moraxella surface proteins]) (msp22, msp75, and msp78, respectively) were determined to be conserved by competitive hybridization using a microarray, PCR, and sequencing of the genes in clinical isolates of M. catarrhalis. The genes were transcribed when M. catarrhalis was grown in vitro. These genes were amplified by PCR and cloned into Escherichia coli expression vectors. Recombinant proteins were generated and then studied using enzyme-linked immunosorbent assays with preacquisition and postclearance serum and sputum samples from 31 adults with chronic obstructive pulmonary disease (COPD) who acquired and cleared M. catarrhalis. New antibody responses to the three proteins were observed for a small proportion of the patients with COPD, indicating that these proteins were expressed during human infection. These studies indicate that the Msp22, Msp75, and Msp78 proteins, whose genes were discovered using genome mining, are highly conserved among strains, are expressed during human infection with M. catarrhalis, and represent potential vaccine antigens.
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43

Luke, Nicole R., Thomas A. Russo, Neal Luther, and Anthony A. Campagnari. "Use of an Isogenic Mutant Constructed inMoraxella catarrhalis To Identify a Protective Epitope of Outer Membrane Protein B1 Defined by Monoclonal Antibody 11C6." Infection and Immunity 67, no. 2 (February 1, 1999): 681–87. http://dx.doi.org/10.1128/iai.67.2.681-687.1999.

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ABSTRACT Moraxella catarrhalis-induced otitis media continues to be a significant cause of infection in young children, prompting increased efforts at identifying effective vaccine antigens. We have previously demonstrated that M. catarrhalis expresses specific outer membrane proteins (OMPs) in response to iron limitation and that this organism can utilize transferrin and lactoferrin for in vitro growth. One of these proteins, which binds human transferrin, is OMP B1. As the human host presents a naturally iron-limited environment, proteins, like OMP B1, which are expressed in response to this nutritional stress are potential vaccine antigens. In this study, we have developed monoclonal antibody (MAb) 11C6, which reacts to a surface-exposed epitope of OMP B1 expressed by M. catarrhalis 7169. This antibody was used to cloneompB1, and sequence analysis suggested that OMP B1 is theM. catarrhalis homologue to the transferrin binding protein B described for pathogenic Neisseriaceae, Haemophilus influenzae, Actinobacillus pleuropneumoniae, andM. catarrhalis. Expression of recombinant OMP B1 on the surface of Escherichia coli confers transferrin binding activity, confirming that this protein is likely involved in iron acquisition. In addition, ompB1 was used to construct an isogenic mutant in M. catarrhalis 7169. This mutant, termed 7169b12, was used as the control in bactericidal assays designed to determine if OMP B1 elicits protective antibodies. In the presence of MAb 11C6 and human complement, wild-type 7169 demonstrated a 99% decline in viability, whereas the ompB1 isogenic mutant was resistant to this bactericidal activity. Further analysis with MAb 11C6 revealed the presence of this OMP B1 epitope on 31% of the clinical isolates tested. These data suggest that OMP B1 is a potential vaccine antigen against M. catarrhalis infections.
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44

Prates, Mirela C. M., Edwin Tamashiro, José L. Proenca-Modena, Miriã F. Criado, Tamara H. Saturno, Anibal S. Oliveira, Guilherme P. Buzatto, et al. "The Relationship between Colonization by Moraxella catarrhalis and Tonsillar Hypertrophy." Canadian Journal of Infectious Diseases and Medical Microbiology 2018 (November 1, 2018): 1–9. http://dx.doi.org/10.1155/2018/5406467.

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We sought to investigate the prevalence of potentially pathogenic bacteria in secretions and tonsillar tissues of children with chronic adenotonsillitis hypertrophy compared to controls. Prospective case-control study comparing patients between 2 and 12 years old who underwent adenotonsillectomy due to chronic adenotonsillar hypertrophy to children without disease. We compared detection of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa, and Moraxella catarrhalis by real-time PCR in palatine tonsils, adenoids, and nasopharyngeal washes obtained from 37 children with and 14 without adenotonsillar hypertrophy. We found high frequency (>50%) of Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Pseudomonas aeruginosa in both groups of patients. Although different sampling sites can be infected with more than one bacterium and some bacteria can be detected in different tissues in the same patient, adenoids, palatine tonsils, and nasopharyngeal washes were not uniformly infected by the same bacteria. Adenoids and palatine tonsils of patients with severe adenotonsillar hypertrophy had higher rates of bacterial coinfection. There was good correlation of detection of Moraxella catarrhalis in different sampling sites in patients with more severe tonsillar hypertrophy, suggesting that Moraxella catarrhalis may be associated with the development of more severe hypertrophy, that inflammatory conditions favor colonization by this agent. Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis are frequently detected in palatine tonsils, adenoids, and nasopharyngeal washes in children. Simultaneous detection of Moraxella catarrhalis in adenoids, palatine tonsils, and nasopharyngeal washes was correlated with more severe tonsillar hypertrophy.
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45

Luke, Nicole R., Simon Allen, Bradford W. Gibson, and Anthony A. Campagnari. "Identification of a 3-Deoxy-d-manno-Octulosonic Acid Biosynthetic Operon in Moraxella catarrhalis and Analysis of a KdsA-Deficient Isogenic Mutant." Infection and Immunity 71, no. 11 (November 2003): 6426–34. http://dx.doi.org/10.1128/iai.71.11.6426-6434.2003.

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ABSTRACT Lipooligosaccharide (LOS), a predominant surface-exposed component of the outer membrane, has been implicated as a virulence factor in the pathogenesis of Moraxella catarrhalis infections. However, the critical steps involved in the biosynthesis and assembly of M. catarrhalis LOS currently remain undefined. In this study, we used random transposon mutagenesis to identify a 3-deoxy-d-manno-octulosonic acid (KDO) biosynthetic operon in M. catarrhalis with the gene order pyrG-kdsA-eno. The lipid A-KDO molecule serves as the acceptor onto which a variety of glycosyl transferases sequentially add the core and branch oligosaccharide extensions for the LOS molecule. KdsA, the KDO-8-phosphate synthase, catalyzes the first step of KDO biosynthesis and is an essential enzyme in gram-negative enteric bacteria for maintenance of bacterial viability. We report the construction of an isogenic M. catarrhalis kdsA mutant in strain 7169 by allelic exchange. Our data indicate that an LOS molecule consisting only of lipid A and lacking KDO glycosylation is sufficient to sustain M. catarrhalis survival in vitro. In addition, comparative growth and susceptibility assays were performed to assess the sensitivity of 7169kdsA11 compared to that of the parental strain. The results of these studies demonstrate that the native LOS molecule is an important factor in maintaining the integrity of the outer membrane and suggest that LOS is a critical component involved in the ability of M. catarrhalis to resist the bactericidal activity of human sera.
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46

Forsgren, Arne, Marta Brant, Mirela Karamehmedovic, and Kristian Riesbeck. "The Immunoglobulin D-Binding Protein MID from Moraxella catarrhalis Is Also an Adhesin." Infection and Immunity 71, no. 6 (June 2003): 3302–9. http://dx.doi.org/10.1128/iai.71.6.3302-3309.2003.

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ABSTRACT The Moraxella catarrhalis immunoglobulin D (IgD)-binding protein (MID) is a 200-kDa outer membrane protein displaying a unique and specific affinity for human IgD. MID is found in the majority of M. catarrhalis strains. In the present paper, we show that MID-expressing M. catarrhalis strains agglutinate human erythrocytes and bind to type II alveolar epithelial cells. In contrast, M. catarrhalis isolates with low MID expression levels and two mutants deficient in MID, but with readily detectable UspA1 expression, do not agglutinate erythrocytes and have a 50% lower adhesive capacity. To examine the adhesive part of MID, the protein was dissected into nine fragments covering the entire molecule. The truncated MID proteins were expressed in Escherichia coli, purified, and used for raising polyclonal antibodies in rabbits. Interestingly, by using recombinant fragments, we show that the hemagglutinating and adhesive part of MID is localized within the 150-amino-acid fragment MID764-913. In addition, antibodies against full-length MID, MID764-913, or a 30-amino-acid consensus sequence (MID775-804) inhibited adhesion to alveolar epithelial cells. Antibodies against UspA1, an outer membrane protein expressed in essentially all M. catarrhalis strains, also inhibited adhesion, suggesting that both MID and UspA1 are needed for optimal attachment to epithelial cells. Taken together, in addition to MID-dependent IgD binding, we have demonstrated that the outer membrane protein MID is a novel adhesin that would be a suitable target for a future vaccine against M. catarrhalis.
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47

Balder, Rachel, Thomas M. Krunkosky, Chi Q. Nguyen, Lacey Feezel, and Eric R. Lafontaine. "Hag Mediates Adherence of Moraxella catarrhalis to Ciliated Human Airway Cells." Infection and Immunity 77, no. 10 (August 10, 2009): 4597–608. http://dx.doi.org/10.1128/iai.00212-09.

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ABSTRACT Moraxella catarrhalis is a human pathogen causing otitis media in infants and respiratory infections in adults, particularly patients with chronic obstructive pulmonary disease. The surface protein Hag (also designated MID) has previously been shown to be a key adherence factor for several epithelial cell lines relevant to pathogenesis by M. catarrhalis, including NCIH292 lung cells, middle ear cells, and A549 type II pneumocytes. In this study, we demonstrate that Hag mediates adherence to air-liquid interface cultures of normal human bronchial epithelium (NHBE) exhibiting mucociliary activity. Immunofluorescent staining and laser scanning confocal microscopy experiments demonstrated that the M. catarrhalis wild-type isolates O35E, O12E, TTA37, V1171, and McGHS1 bind principally to ciliated NHBE cells and that their corresponding hag mutant strains no longer associate with cilia. The hag gene product of M. catarrhalis isolate O35E was expressed in the heterologous genetic background of a nonadherent Haemophilus influenzae strain, and quantitative assays revealed that the adherence of these recombinant bacteria to NHBE cultures was increased 27-fold. These experiments conclusively demonstrate that the hag gene product is responsible for the previously unidentified tropism of M. catarrhalis for ciliated NHBE cells.
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48

Gao, Song, Dabin Ren, Daxin Peng, Wenhong Zhang, Artur Muszyński, Russell W. Carlson, and Xin-Xing Gu. "Late acyltransferase genes lpxX and lpxL jointly contribute to the biological activities of Moraxella catarrhalis." Journal of Medical Microbiology 62, no. 6 (June 1, 2013): 807–12. http://dx.doi.org/10.1099/jmm.0.056846-0.

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Lipo-oligosaccharide (LOS) is a major surface component and virulence factor of the human respiratory pathogen Moraxella catarrhalis. Two late acyltransferase genes, lpxX and lpxL, have been identified involved in the incorporation of acyloxyacyl-linked secondary acyl chains into lipid A during M. catarrhalis LOS biosynthesis. In this study, a double mutant with a deletion of both the lpxX and lpxL genes in M. catarrhalis strain O35E was constructed and named O35ElpxXL. Structural analysis of lipid A showed that the O35ElpxXL mutant lacked two decanoic acids (10 : 0) and one dodecanoic (lauric) acid (12 : 0). In comparison with the O35E parental strain and the single mutants O35ElpxX and O35ElpxL, the double mutant O35ElpxXL displayed prominently decreased endotoxin content, reduced resistance to normal human serum and accelerated bacterial clearance at 0, 3 and 6 h after an aerosol challenge in a mouse model of bacterial pulmonary clearance. These results indicate that these two genes encoding late acyltransferases responsible for lipid A biosynthesis jointly contribute to the biological activities and pathogenicity of M. catarrhalis. The double mutant O35ElpxXL with dramatically reduced toxicity is proposed as a potential vaccine candidate against M. catarrhalis infections for further investigation.
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49

Ndiaye, Aissatou Geuye, Cheikh Saadbou Boye, Edwige Hounkponou, Fatou Bintou Gueye, and Aida Badiane. "Antimicrobial susceptibility of select respiratory tract pathogens in Dakar, Senegal." Journal of Infection in Developing Countries 3, no. 09 (October 22, 2009): 660–66. http://dx.doi.org/10.3855/jidc.20.

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Background : Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes, and Streptococcus pneumoniae are the most common causative agents of respiratory tract infections (RTIs). The increase in resistance to current antibacterial agents highlights the need to monitor the resistance pattern of these bacterial pathogens. Methodology: In this study, we assessed the antibacterial susceptibility of these pathogens causing respiratory tract infections in Dakar, Senegal, during 2007-2008. A total of 290 bacterial isolates (75 H. influenzae, 10 M. catarrhalis, 105 S. pneumoniae, and 100 S. pyogenes) were collected. Results and Conclusions: All H. influenzae isolates were susceptible to amoxicillin/clavulanic acid, ofloxacin, clarithromycin, cephalosporins, and macrolides. Overall, 26.7% of H. influenzae isolates were completely resistant to ampicillin. Among the M. catarrhalis isolates, 30% were resistant to ampicillin. All the isolates of H. influenzae and M. catarrhalis that were resistant to ampicillin were beta-lactamase producing strains. Among the S. pneumoniae isolates, 33.3% isolates exhibited intermediate susceptibility to penicillin G, and one isolate was completely resistant. All five isolates that were resistant to erythromycin expressed the M phenotype. S. pyogenes exhibited high susceptibility to all other antibiotics, except tetracycline. Our study suggests that except for M. catarrhalis, all other bacterial isolates are susceptible to cephalosporins, macrolides, and fluroquinolones.
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50

Yano, Hisakazu, Mitsuko Suetake, Akio Kuga, Kazuhiko Irinoda, Ryoichi Okamoto, Toshimitsu Kobayashi, and Matsuhisa Inoue. "Pulsed-Field Gel Electrophoresis Analysis of Nasopharyngeal Flora in Children Attending a Day Care Center." Journal of Clinical Microbiology 38, no. 2 (2000): 625–29. http://dx.doi.org/10.1128/jcm.38.2.625-629.2000.

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To investigate how bacterial pathogens spread from child to child in a day care center, we monitored six children, two boys and four girls, born between August 1995 and November 1997, attending a day care center and analyzed nasopharyngeal samples from them using pulsed-field gel electrophoresis (PFGE). We obtained nasopharyngeal cultures from all of the affected children and almost all of the unaffected children between September 1998 and March 1999 after some children presented simultaneously with purulent rhinorrhea. Moreover, when a child was found to have acute otitis media, nasopharyngeal secretions from the child were independently cultured during treatment. During this period, 28 isolates of Moraxella catarrhalis, 13 ofStreptococcus pneumoniae, and 4 of Haemophilus influenzae were recovered. PFGE gave 8 patterns for M. catarrhalis, 10 for S. pneumoniae, and 1 for H. influenzae. PFGE patterns demonstrated spread of M. catarrhalis between children. However, each occurrence of clusters of infection with M. catarrhalis lasted 2 to 6 weeks, with a change in PFGE pattern between occurrences of clusters. The M. catarrhalis strain infecting each child also changed. Similarly, the S. pneumoniae strain in each child also changed. In contrast, infection with H. influenzaepersisted for about 3 months in an affected child.
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