Relevant bibliographies by topics / QacA

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Academic literature on the topic 'QacA'

Author: Grafiati
Published: 6 September 2023

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Journal articles on the topic "QacA"

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Bayer, A. S., L. I. Kupferwasser, M. H. Brown, R. A. Skurray, S. Grkovic, T. Jones, K. Mukhopadhay, and M. R. Yeaman. "Low-Level Resistance of Staphylococcus aureus to Thrombin-Induced Platelet Microbicidal Protein 1 In Vitro Associated with qacA Gene Carriage Is Independent of Multidrug Efflux Pump Activity." Antimicrobial Agents and Chemotherapy 50, no. 7 (July 2006): 2448–54. http://dx.doi.org/10.1128/aac.00028-06.

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ABSTRACT Thrombin-induced platelet microbial protein 1 (tPMP-1), a cationic antimicrobial polypeptide released from thrombin-stimulated rabbit platelets, targets the Staphylococcus aureus cytoplasmic membrane to initiate its microbicidal effects. In vitro resistance to tPMP-1 correlates with survival advantages in vivo. In S. aureus, the plasmid-carried qacA gene encodes a multidrug transporter, conferring resistance to organic cations (e.g., ethidium [Et]) via proton motive force (PMF)-energized export. We previously showed that qacA also confers a tPMP-1-resistant (tPMP-1r) phenotype in vitro. The current study evaluated whether (i) transporters encoded by the qacB and qacC multidrug resistance genes also confer tPMP-1r and (ii) tPMP-1r mediated by qacA is dependent on efflux pump activity. In contrast to tPMP-1r qacA-bearing strains, the parental strain and its isogenic qacB- and qacC-containing strains were tPMP-1 susceptible (tPMP-1s). Efflux pump inhibition by cyanide m-chlorophenylhydrazone abrogated Etr, but not tPMP-1r, in the qacA-bearing strain. In synergy assays, exposure of the qacA-bearing strain to tPMP-1 did not affect the susceptibility of Et (ruling out Et-tPMP-1 cotransport). The following cytoplasmic membrane parameters did not differ significantly between the qacA-bearing and parental strains: contents of the major phospholipids; asymmetric distributions of the positively charged species, lysyl-phosphotidylglycerol; fatty acid composition; and relative surface charge. Of note, the qacA-bearing strain exhibited greater membrane fluidity than that of the parental, qacB-, or qacC-bearing strain. In conclusion, among these families of efflux pumps, only the multidrug transporter encoded by qacA conferred a tPMP-1r phenotype. These data suggest that qacA-encoded tPMP-1r results from the impact of a specific transporter upon membrane structure or function unrelated to PMF-dependent peptide efflux.
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Kawai, Mako, Sakuo Yamada, Ai Ishidoshiro, Yoshihiro Oyamada, Hideaki Ito, and Jun-ichi Yamagishi. "Cell-wall thickness: possible mechanism of acriflavine resistance in meticillin-resistant Staphylococcus aureus." Journal of Medical Microbiology 58, no. 3 (March 1, 2009): 331–36. http://dx.doi.org/10.1099/jmm.0.004184-0.

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Acriflavine resistance in the clinical meticillin-resistant Staphylococcus aureus isolate KT24 was found not to be mediated by multidrug efflux pumps encoded by qacA/B, smr, qacE, qacG, qacH, qacJ or norA. Early uptake and accumulation of ethidium bromide in MRSA KT24 was significantly lower than that in a susceptible strain, although the efflux rates were similar. Therefore, a permeability barrier in MRSA KT24 may be the conceivable mechanism of acriflavine resistance. Interestingly, it was found that MRSA KT24 had a significantly thickened cell wall, and that cell-wall thickness increased gradually during bacterial growth. In contrast, cell size and surface area in MRSA KT24 were not different from those in the susceptible strain. Moreover, MRSA KT24 exposure to sub-MIC concentrations of acriflavine resulted in a thicker cell wall. These results indicate that cell-wall thickness may be responsible for acriflavine resistance in S. aureus.
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He, Gui-Xin, Michael Landry, Huizhong Chen, Conner Thorpe, Dennis Walsh, Manuel F. Varela, and Hongmiao Pan. "Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci." Journal of Medical Microbiology 63, no. 5 (May 1, 2014): 735–41. http://dx.doi.org/10.1099/jmm.0.073072-0.

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We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02–0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.
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Nakaminami, Hidemasa, Norihisa Noguchi, and Masanori Sasatsu. "Fluoroquinolone Efflux by the Plasmid-Mediated Multidrug Efflux Pump QacB Variant QacBIII in Staphylococcus aureus." Antimicrobial Agents and Chemotherapy 54, no. 10 (July 26, 2010): 4107–11. http://dx.doi.org/10.1128/aac.01065-09.

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ABSTRACT Plasmids that carry the multidrug efflux genes qacA and qacB are widely distributed in methicillin-resistant Staphylococcus aureus (MRSA). Although the QacA and QacB proteins are similar to each other, their respective substrate specificities may differ. We investigated the variability and structure-function relationships of QacA and QacB in MRSA isolates. The amino acid sequences of 7 QacA and 25 QacB proteins showed that QacB was present in three variants, designated QacBII, QacBIII, and QacBIV, that were different from the prototypic QacB variant encoded by plasmid pSK23, which was named QacBI, while QacA was present in two variants. When cloned and expressed in S. aureus, the strain carrying qacBIII exhibited higher susceptibility to dyes and decreased susceptibility to norfloxacin and ciprofloxacin compared to strains carrying the other QacB variants. Site-directed mutagenesis experiments revealed that the residue at position 320 in QacB plays an important role in the resistance phenotypes to dyes and fluoroquinolones. Furthermore, the accumulation of norfloxacin and ciprofloxacin in the strain carrying qacBIII was significantly decreased. Our data demonstrate that the plasmid-mediated multidrug efflux pump QacB variant QacBIII confers the capability for fluoroquinolone efflux on S. aureus.
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Bjorland, Jostein, Terje Steinum, Marianne Sunde, Steinar Waage, and Even Heir. "Novel Plasmid-Borne Gene qacJ Mediates Resistance to Quaternary Ammonium Compounds in Equine Staphylococcus aureus, Staphylococcus simulans, and Staphylococcus intermedius." Antimicrobial Agents and Chemotherapy 47, no. 10 (October 2003): 3046–52. http://dx.doi.org/10.1128/aac.47.10.3046-3052.2003.

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ABSTRACT We identified a novel plasmid-borne gene (designated qacJ) encoding resistance to quaternary ammonium compounds (QACs) in three staphylococcal species associated with chronic infections in four horses. qacJ was located on a 2,650-bp plasmid (designated pNVH01), a new member of the pC194 family of rolling-circle replication plasmids. The 107-amino-acid protein, QacJ, showed similarities to known proteins of the small multidrug resistance family: Smr/QacC (72.5%), QacG (82.6%), and QacH (73.4%). The benzalkonium chloride MIC for a qacJ-containing recombinant was higher than those for otherwise isogenic recombinants expressing Smr, QacG, or QacH. Molecular epidemiological analyses by pulsed-field gel electrophoresis suggested both the clonal spread of a qacJ-harboring Staphylococcus aureus strain and the horizontal transfer of pNVH01 within and between different equine staphylococcal species. The presence of pNVH01 of identical nucleotide sequence in different staphylococcal species suggests that recent transfer has occurred. In three of the horses, a skin preparation containing cetyltrimethylammonium bromide had been used extensively for several years; this might explain the selection of staphylococci harboring the novel QAC resistance gene.
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Ergun, Y., Z. Cantekin, K. Gurturk, H. Solmaz, IH Ekin, and D. Ozturk. "Distribution of antiseptic resistance genes in Staphylococcus spp. from bovine mastitis." Veterinární Medicína 62, No. 4 (April 10, 2017): 200–203. http://dx.doi.org/10.17221/265/2015-vetmed.

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The purpose of this study was the determination of antiseptic resistance genes (qacA/B and qacC) from staphylococcal mastitis in cattle in various regions of Turkey. In total, 283 isolates (Burdur: 36, Hatay: 47 and Van: 200) were studied, and the antiseptic resistance genes were detected using simplex PCR. The distribution of the qacA/B and qacC genes, mediating resistance against quaternary ammonium compounds, was found to vary among the different isolates. The qacA/B genes were found in three of the Burdur isolates, six of the Hatay isolates and seven of the Van isolates. The qacC gene was found in two of the Burdur isolates, none of the Hatay isolates and two of the Van isolates. The presence of these genes and transmission among Staphylococcus spp. strains may pose risks in the control of mastitis, as well as to public health.
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Et al., Saber. "Detection a New Antiseptic Resistant Variant of qac Gene in Some Multi Drug Resistant Staphylococcus aureus Isolated from Different Clinical Sources." Baghdad Science Journal 16, no. 3 (September 1, 2019): 0571. http://dx.doi.org/10.21123/bsj.2019.16.3.0571.

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The increasing use of antiseptic compounds creates selective pressure cause emergence of antiseptic resistance among Staphylococcus aureus .Resistance mechanism of antiseptic is driven mainly by multi drug resistant (MDR) efflux protein.Sixty five isolates of S.aureuswere collected from different clinical sources and subjected to 11 antibiotics most of them are recognized by efflux systems as extruded substrates. Range of efflux activity was estimated using cartwheel method. Simultaneous discrimination of antiseptic coding genes (qacA/B, smr and norA)as well as nuc and mecA genes among multidrug resistantS.aureus(MRSA) isolates was preformed using multiplex PCR assay , 61 isolatesamong 65 were positive tonucand mecA genes, 58 of them were positive to norA, 14 of them were positive to qacA/B and only two were positive to smr. All isolates detected with qacA/B characterized by fluoroquinolones resistant and most of them show strong efflux activity at cartwheel assay, all of the 14 isolates positive qacA/B were sequenced to differentiate between variants depending on position 323 (aspartic in QacA, alanine in QacB), 3 of them harbored asparagines amino acid at position 323 and considered to be a new variants that reported for the first time.
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Paulsen, Ian T., Melissa H. Brown, and Ronald A. Skurray. "Characterization of the Earliest KnownStaphylococcus aureus Plasmid Encoding a Multidrug Efflux System." Journal of Bacteriology 180, no. 13 (July 1, 1998): 3477–79. http://dx.doi.org/10.1128/jb.180.13.3477-3479.1998.

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ABSTRACT The staphylococcal qacB-encoding multidrug resistance plasmid pSK156, isolated from a clinical strain dating from 1951, was characterized. Comparison of the regions flanking qacB with other qacA- and qacB-encoding plasmids provided insights into the evolution and dissemination of these multidrug efflux genes and led to the detection of the earliest known copy of the insertion sequence IS257.
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Sidhu, Maan Singh, Even Heir, Truls Leegaard, Karianne Wiger, and Askild Holck. "Frequency of Disinfectant Resistance Genes and Genetic Linkage with β-Lactamase Transposon Tn552 among Clinical Staphylococci." Antimicrobial Agents and Chemotherapy 46, no. 9 (September 2002): 2797–803. http://dx.doi.org/10.1128/aac.46.9.2797-2803.2002.

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ABSTRACT A total of 61 strains of Staphylococcus aureus and 177 coagulase-negative staphylococcal strains were isolated from the blood of patients with bloodstream infections and from the skin of both children under cancer treatment and human immunodeficiency virus-positive patients. The MIC analyses revealed that 118 isolates (50%) were resistant to quaternary ammonium compound-based disinfectant benzalkonium chloride (BC). The frequencies of resistance to a range of antibiotics were significantly higher among BC-resistant staphylococci than among BC-sensitive staphylococci. Of 78 BC-resistant staphylococcal isolates, plasmid DNA from 65 (83%), 2 (3%), 43 (55%), and 15 (19%) isolates hybridized to qacA or -B (qacA/B), qacC, blaZ, and tetK probes, respectively. The qacA/B and blaZ probes hybridized to the same plasmid in 19 (24%) staphylococcal strains. The plasmids harboring both qacA/B and blaZ genes varied from approximately 20 to 40 kb. The Staphylococcus epidermidis Fol62 isolate, harboring multiresistance plasmid pMS62, contained qacA/B and blaZ together with tetK. Molecular and genetic studies indicated different structural arrangements of blaZ and qacA/B, including variable intergenic distances and transcriptional directions of the two genes on the same plasmid within the strains. The different organizations may be due to the presence of various genetic elements involved in cointegration, recombination, and rearrangements. These results indicate that qac resistance genes are common and that linkage between resistance to disinfectants and penicillin resistance occurs frequently in clinical isolates in Norway. Moreover, the higher frequency of antibiotic resistance among BC-resistant strains indicates that the presence of either resistance determinant selects for the other during antimicrobial therapy and disinfection in hospitals.
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Kiley, John L., Dana M. Blyth, Dana M. Blyth, Miriam Beckius, Susan Kaiser, M. Leigh Carson, Dan Lu, et al. "543. Biocide Resistance Genes in Klebsiella spp. Infections from Trauma Patients in Iraq and Afghanistan." Open Forum Infectious Diseases 6, Supplement_2 (October 2019): S259. http://dx.doi.org/10.1093/ofid/ofz360.612.

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Abstract Background Biocides play an integral role in infection control. Paralleling concern about rising incidence of multidrug-resistant (MDR) organisms is a concern for resistance to biocides. In small studies, several genes involved in the production of efflux pump proteins have been identified as markers of biocide resistance in Klebsiella spp., namely cepA, qacA, qacE, qac∆E, and acrA. This study aimed to analyze the Klebsiella spp. isolates of a previously defined military trauma group with a high incidence of MDR organisms for the presence of these genes and their correlation with other resistance. Methods All infecting K. pneumoniae, K. variicola, and K. quasipneumoniae isolates archived by the Trauma Infectious Disease Outcomes Study (June 2009–December 2014) were selected. Additionally, all colonizing isolates linked with infecting isolates were included; the remainder to total 50 MDR and 46 non-MDR colonizing isolates were chosen randomly. Antimicrobial identification and susceptibilities were determined by CLSI criteria using the BD Phoenix Automated Microbiology System. PCR according to published methods for cepA, qacA, qacE, qac∆E, and acrA was accomplished in duplicate. MDR was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of an ESBL or KPC. Results A total of 237 isolates (221 K. pneumoniae, 10 K. variicola, 6 K. quasipneumoniae) met inclusion criteria, of which 149 (63%) were MDR. All isolates had been exposed to antimicrobials prior to isolation. Of all isolates, 234 (98%) carried cepA: 218 (98%) K. pneumoniae carried cepA, 10 (100%) K. variicola carried cepA, and 6 (100%) of K. quasipneumoniae carried cepA. In addition, 148 (62%) isolates with cepA were MDR. One (10%) K. variicola isolate carried qacE along with cepA. This isolate was the only MDR K. variicola. None of the isolates carried qacA, qac∆E, or acrA. Conclusion We confirmed the near universal presence of the cepA biocide resistance gene in Klebsiella spp. isolated from trauma patients in Iraq and Afghanistan. In the largest evaluation of biocide resistance genes in Klebsiella spp. to our knowledge, the presence of qacA, qacE, qac∆E, and acrA was less common than has been reported elsewhere. Disclosures All authors: No reported disclosures.
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Dissertations / Theses on the topic "QacA"

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Xu, Zhiqiang. "Molecular analysis of staphylococcal multidrug transport protein QacA." Thesis, The University of Sydney, 2005. https://hdl.handle.net/2123/27983.

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The multidrug exporter QacA from Staphylococcus aureus confers resistance to a wide range of structurally-dissimilar monovalent and bivalent lipophilic, cationic compounds, including intercalating dyes, quaternary ammonium compounds (Qacs), diamidines, and biguanidines, many of which are used as antiseptics and disinfectants in current applications. To overcome such a problem, detailed understanding of the substrate-recognition and transport mechanisms of QacA is crucial. High-resolution structural studies of QacA can provide critical insights to these mechanisms. The preliminary requirement of such studies is a regular supply of purified QacA protein in milligram quantities. In this study, an over-expression and purification system of QacA based on the E. coli expression vector pTTQ18His6 was established. Conditions for the over-expression and purification of the QacA protein were optimized, resulting in a yield of approximately 600 pg of purified protein from 1 litre of bacterial culture. Circular dichroism (CD) spectroscopic analysis suggested that the purified QacA protein was structurally integral as demonstrated by its predominantly oc-helical structure, and substrate-binding assays were also performed.
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Mourato, Cláudia Alhinho. "A contribuição das bombas de efluxo QacA e Smr para a multirresistência em Staphylococcus aureus." Master's thesis, Faculdade de Ciências Médicas. Universidade Nova de Lisboa, 2012. http://hdl.handle.net/10362/7718.

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RESUMO: O efluxo de compostos antimicrobianos é um mecanismo importante na multirresistência em bactérias. Bombas de efluxo codificadas em plasmídeos, como a QacA e a Smr, estão implicadas na susceptibilidade reduzida a biocidas, geralmente utilizados na prevenção e controlo de infecções nosocomiais, incluindo as causadas por estirpes de Staphylococcus aureus resistentes à meticilina (MRSA). Neste trabalho pretendeu-se avaliar a relevância de QacA e Smr no perfil de susceptibilidade dos isolados clínicos MRSA SM39 e SM52, que transportam os plasmídeos pSM39 e pSM52 com os determinantes qacA e smr, respectivamente. A actividade de efluxo das estirpes SM39 e SM39 curada (sem pSM39) e das estirpes SM52 e RN4220:pSM52 (estirpe susceptível RN4220 transformada com pSM52) foi caracterizada por: (1) determinação da concentração mínima inibitória (CMI) de biocidas, corantes e antibióticos, na ausência e presença dos inibidores de efluxo tioridazina, clorpromazina, verapamil e reserpina; e (2) fluorometria em tempo-real. A determinação de CMIs demonstrou que a actividade de efluxo mediada por QacA e Smr está envolvida na susceptibilidade reduzida aos biocidas e corantes testados, que incluíram o brometo de hexadeciltrimetilamónio, a cetrimida, o cloreto de benzalcónio, a berberina, o cloreto de dequalínio, a pentamidina e o brometo de etídeo. Os ensaios fluorométricos confirmaram a elevada actividade de efluxo presente nas estirpes com os genes qacA ou smr. A determinação de CMIs para antibióticos β-lactâmicos em conjunto com o teste da nitrocefina revelou a presença simultânea do gene qacA e de uma β-lactamase no plasmídeo pSM39. Este trabalho evidencia a importância das bombas de efluxo QacA e Smr na resistência a biocidas em estirpes MRSA e na sobrevivência destas estirpes em ambiente hospitalar e na comunidade, para além de destacar a questão da potencial co-resistência entre biocidas e antibióticos.--------------- ABSTRACT: Drug efflux has become an important cause of multidrug resistance (MDR) in bacteria. Plasmid-encoded MDR efflux pumps, such as QacA and Smr, are implicated in reduced susceptibility to biocides, generally used in the prevention and control of nosocomial infections, including the ones caused by methicillin-resistant Staphylococcus aureus (MRSA). In this work, we aimed to evaluate the relevance of QacA and Smr to the susceptibility profile of the clinical MRSA isolates SM39 and SM52, which harbor the plasmids pSM39 and pSM52 that carry the determinants qacA and smr, respectively. Efflux activity of strain SM39 and its plasmid-free counterpart, SM39 cured, SM52 and RN4220:pSM52 (susceptible strain RN4220 transformed with pSM52) was characterized by: (1) determination of minimum inhibitory concentration (MIC) of biocides, dyes and antibiotics, in the absence and presence of the efflux inhibitors thioridazine, chlorpromazine, verapamil and reserpine; and (2) real-time fluorometry. MIC determination showed that QacA and Smr mediated efflux was involved in the reduced susceptibility profile to the biocides and dyes tested, which included hexadecyltrymethylammonium bromide, cetrimide, benzalkonium chloride, berberine, dequalinium chloride, pentamidine and ethidium bromide. Fluorometric assays confirmed the higher efflux activity present in strains harboring qacA or smr genes. Moreover, MIC determination for β-lactam antibiotics together with the nitrocefin test confirmed the presence of a β-lactamase in the plasmid carried by SM39 strain, pSM39. This work highlights the relevance of QacA and Smr to the biocide resistance in MRSA strains, and consequently to their survival and maintenance in the hospital environment and in the community. Furthermore, the presence of a β-lactamase and qacA determinants in the the same plasmid reinforces the question of the potencial biocide/antibiotic co-resistance in MRSA strains.
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Vale, Bruna Costa Moura do. "Redu??o da susceptibilidade ? clorexidina e distribui??o dos genes qacA/B em isolados de estafilococos coagulase-negativa." PROGRAMA DE P?S-GRADUA??O EM CI?NCIAS BIOL?GICAS, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/24056.

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As infec??es relacionadas ? assist?ncia ? sa?de (IRAS) s?o atualmente um dos principais problemas de sa?de p?blica. Os estafilococos coagulase-negativa (ECN) est?o entre as esp?cies mais prevalentes neste tipo de infec??o, devido ? sua capacidade de colonizar dispositivos m?dicos invasivos. A clorexidina ? extensivamente utilizada no ambiente hospitalar como forma de preven??o e controle de IRAS. No entanto, a literatura relata a exist?ncia de cepas com susceptibilidade reduzida ocasionada possivelmente pela presen?a dos genes qacA/B. O objetivo do estudo foi investigar a susceptibilidade ? clorexidina e sua rela??o com a presen?a dos genes qacA/B em 211 isolados de ECN provenientes de diferentes hospitais da cidade do Natal-RN. As amostras foram identificadas por testes bioqu?micos convencionais; a susceptibilidade ? antimicrobianos foi realizada pela metodologia disco-difus?o; a determina??o da Concentra??o Inibit?ria M?nima (CIM) para a clorexidina foi avaliada pela t?cnica de dilui??o em ?gar; a t?cnica da PCR foi utilizada para pesquisar os genes qacA/B e o gene mecA. No total de 211 amostras de ECN, 69% foram isolados a partir hemoculturas. As esp?cies mais frequentes foram S. epidermidis, S. hominis hominis, S. auricularis e S. haemolyticus, respectivamente. As cepas apresentaram um perfil de resist?ncia a multidrogas de 87%, incluindo resist?ncia ? oxacilina; 31% demonstraram susceptibilidade reduzida ? clorexidina. Os genes qacA/B foram detectados tanto em amostras resistentes ? clorexidina (32/32) quanto em amostras suscept?veis (17/32). Grande parte das cepas com susceptibilidade reduzida ? clorexidina exibiram tamb?m multirresist?ncia aos antibi?ticos testados (94%). A identifica??o de cepas com susceptibilidade reduzida ? clorexidina nesse estudo representa uma amea?a as pr?ticas de controle de IRAS. Apesar de todas as cepas resistentes ? clorexidina possu?rem os genes qacA/B, sua presen?a n?o foi um fator determinante para a express?o da resist?ncia, necessitando de estudos adicionais. A diminui??o da susceptibilidade ? antiss?pticos pode levar ? persist?ncia bact?rias no ambiente hospitalar contribuindo, dessa forma, para a sobreviv?ncia de cepas multirresistentes.
Health Care Associated Infections (HAI) are currently a of major public health problem. The coagulase-negative Staphylococci (CNS) are among the most prevalent species in this type of infection due to their ability to colonize invasive medical devices. Chlorhexidine is extensively used in the hospital setting as a means of prevention and control of HAI. However, the existence of strains with reduced susceptibility caused possibly by the presence of the qacA/B genes has been reported in the literature. The main of this study was to investigate the susceptibility to chlorhexidine and its relation to the presence of the qacA/B genes in 211 isolates of ECN from diferente hospitals in the city of Natal-RN. Samples were identified by standard biochemical tests; the susceptibility to antimicrobials was performed using the disc-diffusion methodology; the susceptibility to chlorhexidine was evaluated by determining the Minimum Inhibitory Concentration (MIC) by the agar dilution technique; the PCR method was used to investigate the qacA/B genes and mecA gene. In total of 211 CNS samples, 69% were isolated from blood cultures. The most frequent species were S. epidermidis, S. hominis hominis, S. auricularis and S. haemolyticus, respectively. The strains had a multidrug resistance profile of 87%, including resistance to oxacillin; 31% demonstrated reduced susceptibility to chlorhexidine. The qacA/B genes were detected in both chlorhexidine resistant (32/32) and susceptible samples (17/32). Most of the strains with reduced susceptibility to chlorhexidine also showed multidrug resistance to the tested antibiotics (94%). Identification of strains with reduced susceptibility to chlorhexidine in this study poses a threat to HAIs control practices. Although all strains resistant to chlorhexidine had the qacA/B genes, their presence was not a determining factor for the expression of the resistance, requiring additional studies. The decrease in susceptibility to antiseptics may allow bacteria to persist in the hospital environment, thus contributing to the survival of multiresistant strains.
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MORANDINI, ANDREA. "SYNTHESIS AND USE OF TRIAZINYL QACs AS ANTIMICROBIAL AGENTS." Doctoral thesis, Università degli Studi di Trieste, 2021. http://hdl.handle.net/11368/2988358.

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L’aumento dello sviluppo di microorganismi in grado di resistere alle più comuni sostanze antimicrobiche negli ultimi anni è un fenomeno che da tempo preoccupa le varie organizzazioni della salute mondiale. Lo sviluppo della resistenza alle sostanze avverse è un meccanismo naturale, che i microorganismi hanno sfruttato fin dall’antichità. Con l’avvio verso l’industrializzazione ai primi del XX secolo e la scoperta di potenti farmaci antibiotici, l’umanità ha potuto notevolmente migliorare il suo stile di vita. Il risultato di decenni di utilizzo irresponsabile e sperpero nell’ambiente di queste sostanze antimicrobiche però ha inevitabilmente portato alla generazione di microorganismi antibiotico resistenti. L’umanità, se meglio vuole arginare questo fenomeno, in futuro dovrà agire con più coscienza, limitando gli sprechi, utilizzando prodotti che meglio preservino l’ambiente e sviluppando nuove sostanze antimicrobiche efficaci. In questa lavoro di dottorato si descrive la sintesi di nuovi sali d’ammonio quaternario antimicrobici (QACs), sfruttando la grande reattività dalle cloro triazine. Diversi QACs triazinici sono stati sintetizzati e la loro attività antimicrobica è stata investigata. In prima istanza ci si è concentrati sulla sintesi di una libreria di QACs morfolino-triazinici di diretta ispirazione alla struttura della 4-(4,6-dimetossi-1,3,5-triazin-2-il)-4-metil-morfolinio cloruro o DMTMM. Valutandone poi l’efficacia contro ceppi batterici Gram-positivi e Gram-negativi come Staphylococcus aureus ed Escherichia coli. Successivamente si è passati alla sintesi di una libreria di QACs imidazolo-triazinici che hanno mostrato prestazioni superiori rispetto ai primi QACs morfolino-triazinici, sia in termini di resa delle reazioni che in termini di attività antimicrobica. Infine, è stata descritta la sintesi di vari polimeri a blocchi basati sulla 2-N-morfolinoetil metilmetacrilato (MEMA) e il loro utilizzo nella preparazione di QACs polimerici e superfici antimicrobiche.
The increased development of microorganisms capable of resisting the most common antimicrobial substances, in recent years, is a phenomenon that has long been of concern to various global health organizations. The development of resistance to adverse substances is a natural mechanism, which microorganisms have exploited since ancient times. With the onset of industrialization in the early 20th century and the discovery of powerful antibiotic drugs, mankind has been able to significantly improve its lifestyle. The result of decades of irresponsible use and wastage of these antimicrobial substances in the environment, however, has inevitably led to the generation of antibiotic-resistant microorganisms. Humanity, if it wants to better contain this phenomenon, in the future will have to act with more conscience, limiting waste, using products that better preserve the environment and developing new effective antimicrobial substances. In this Ph.D. work we describe the synthesis of novel antimicrobial quaternary ammonium salts (QACs) by exploiting the high reactivity of chloro triazines. Several triazine QACs were synthesized and their antimicrobial activity was investigated. In the first instance, we focused on the synthesis of a library of morpholino-triazine QACs directly inspired by the structure of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride or DMTMM. Then evaluating its efficacy against Gram-positive and Gram-negative bacterial strains such as Staphylococcus aureus and Escherichia coli. Next, we moved on to the synthesis of a library of imidazole-triazine QACs that showed superior performance compared to the first morpholino-triazine QACs, both in terms of yield and antimicrobial activity. Finally, the synthesis of various blockcopolymers based on 2-N-morpholinoethyl methylmethacrylate (MEMA) and their use in the preparation of polymeric QACs and antimicrobial surfaces was described.
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Ndima, Mlungisi. "A history of the Qwathi people from earliest times to 1910." Thesis, Rhodes University, 1989. http://hdl.handle.net/10962/d1002402.

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This is the first history of the Qwathi to appear. It relates all the events which have shaped the historical consciousness of the Qwathi people. The first chapter deals with the foundation of the Qwathi chiefdom by Mtshutshumbe and his followers who emigrated from EmaXesibeni to Thembuland before 1700. It also covers the development of the various Qwathi clans. The reign of Fubu which is discussed in Chapter Two was characterised by warfare. The most important of these wars was the Qwathi-Thembu war of the beginning of the nineteenth century. Its importance lies in the fact that although the Qwathi were a small chiefdom, they were able to goad the Thembu nation into war, the results of which were indecisive, hence, in subsequent years, the Thembu were always cautious in their dealings with the Qwathi. Fubu's other wars, including those of the Mfecane, are also discussed. Chapter Three deals mainly with the Qwathi-Thembu relations during the reign of Dalasile, Fubu's son. These were at first cordial but they became strained when Ngangelizwe took over as Thembu king in 1863. Dalasile refused to involve the Qwathi people in Thembu conflicts with their enemies and he desired to pursue an independent line. In 1875, when Ngangelizwe accepted colonial control, Dalasile stood out against it but, under pressure from the agents of colonialism, he gave in. The period from 1875 to 1880 was one of passive resistence to colonial control. This erupted into Dalasile's rebellion against the colony from 1880 to 1881. Chapter Six deals with the surrender, relocation and the introduction of a new system of control called the "Ward System". The ruling house was replaced by appointed headmen most of whom were drawn from non-Qwathi communities. Chapter Seven deals with the rise and Fall of the Qwathi peasantry. The fall of the peasantry facilitated labour migracy which contributed to further deterioration of the Qwathi both economically and physically.
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Walker, Molly C. "Masterplan for a healing garden in the village of Qala-e-Malakh, Behsood District, Nangarhar Province, Afghanistan." Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1379443.

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This creative project is the exploration of a healing garden for Afghan women who have been victims of war and terror. The project culminates with a masterplan and design for a healing garden in the rural village of Qala-e-Malakh in the Behsood District of the Nangarhar Province of Afghanistan. This issue became a viable project when I was put into contact with Lalbibi (Bibi) Bahrami, an Afghan woman living in Yorktown, Indiana, and native of Qala-e-Malakh. She has worked tirelessly to create and raise funds for her organization, Afghan Women's And Kids' Education and Necessities (AWAKEN), which provides education, basic healthcare, and vocational training to women and children in several rural villages. It is my intent to determine how a designed space, incorporating elements of native culture, emotional treatment standards, and therapeutic garden research, can help heal and renew the spirits of women who have experienced such extreme tragedy and devastation.
Department of Landscape Architecture
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7

Rodríguez, Coll Pablo 1985. "Adaptación y validación del "Questionnaire for Assessing the Childbirth Experience (QACE)" en mujeres españolas." Doctoral thesis, Universitat Pompeu Fabra, 2021. http://hdl.handle.net/10803/672354.

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El "Questionnaire for Assessing the Childbirth Experience (QACE)" busca identificar mujeres con una experiencia negativa del parto y evitar que tenga repercusiones en siguientes embarazos o en su relación de pareja. El objetivo de la tesis es adaptar y validar el QACE desde el inglés al castellano de España, así como describir los resultados obstétricos y el nivel de satisfacción en el parto de los dos hospitales participantes. Este estudio concluye en tres principales resultados: a) el CEEP ha sido adaptado y traducido de forma metodológicamente correcta, tiene una buena consistencia interna (ω=0,818) y es estable en el tiempo (CCI 0,94, p ,00); b) el anàlisis factorial confirmatorio mostró un ajuste adecuado/bueno con 20 ítems clasificados en cuatro factores que explicaban el 52,63% del total de la varianza; c) la satisfacción con el parto es similar en ambos hospitales, aunque el hospital de menor complejidad tiene mejores resultados obstétricos.
The "Questionnaire for Assessing the Childbirth Experience (QACE)" seeks to detect those women who have had a negative experience in childbirth and avoid having repercussions in subsequent pregnancies or in their relationship. The objective of the thesis is to obtain, adapt and validate the QACE from English to the Spanish version of Spain, as well as to describe the obstetrical results and the birth satisfaction level between the participant hospitals. This study concludes in three main results: a) CEEP has been adapted and translated in a methodologically correct manner, internal consistency was assured (ω=0,818) and is stable over time (ICC 0.94, p <.00); b) confirmatory factor analysis was good/adequate with 20 items classified in four factors that explained 52.63% of the variance; c)in terms of birth satisfaction, similar results were obtained in both hospitals. However, there are better obstretrical outcomes in the hospital with less complexity.
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Berrospi, Torres Ivan, Corales Brigitte Gallarday, Durand Ana Patricia Mantilla, Guillermo Mishell Mercedes Peralta, and Peralta Clodoaldo Kevin Yñigo. "Qara Sumaq: emprendimiento de mascarilla facial a base de arcillas cosméticas y agar agar." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/654797.

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En el presente trabajo, se ejecutó un plan de negocios de mascarillas faciales a base de arcillas cosméticas y agar agar, creado por cinco estudiantes de la facultad de Negocios de la Universidad Peruana de Ciencias Aplicadas (UPC). El proyecto se desarrolló en base a la necesidad que tienen las mujeres en encontrar productos cosméticos con ingredientes naturales que no contengan productos químicos que puedan dañar su piel y que sean amigables con el medio ambiente. Al analizar el mercado de belleza, pudimos apreciar que el crecimiento de este sector es constante y la tendencia a consumir productos de belleza naturales está en proceso de crecimiento. Luego de evaluar las necesidades y requerimientos de nuestro público objetivo, desarrollamos las fórmulas de las tres versiones de mascarillas, usando insumos naturales que cumplen diferentes funciones como purificar, regenerar y limpiar profundamente la piel. El objetivo de este proyecto es poder comercializarlas. Al finalizar nuestro proyecto de ventas, se analizaron los diferentes planes presupuestales del área de RRHH, de operaciones, marketing y de Responsabilidad Social Corporativa, para tener una proyección, en términos monetarios, de lo que necesitamos para llevar a cabo nuestra idea de negocio. Con ello, seremos capaces de saber si es aceptable invertir en él o en todo caso, aprender y crear nuevas ideas de negocio. Los objetivos planteados en este proyecto han sido alcanzados a plenitud, como también los datos encontrados facilitaron el logro de estos.
In the present work, a business plan for facial masks based on clays and agar agar was executed, created by five students from the Business School of the Peruvian University of Applied Sciences (UPC). The project was developed based on the need for women to find cosmetic products with natural ingredients that do not contain chemicals that can damage their skin and that are friendly to the environment. When analysing the beauty market, we could see that the growth of this sector is constant and the trend to consume natural beauty products is growing. After evaluating the needs of our target audience, we developed the formulas for the three versions of masks, using natural inputs that fulfil different functions such as purifying, regenerating and deeply cleansing the skin. The objective of this project is to be able to commercialize them. At the end of our sales project, the different budget plans for the HR, operations, marketing and Corporate Social Responsibility areas will be analysed to have a projection of what we need to carry out our business idea. In addition, to better examine our model, the total project was evaluated to see if it would generate value and if it is profitable. With this, we will be able to know if it is acceptable to invest in it or in any case, learn and create new business ideas. Therefore, the objectives set out in this project have been fully achieved, as well as the data found facilitated their achievement.
Trabajo de investigación
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Khan, Azra. "An investigation into the association of plasmid-borne qacAB and antimicrobial resistance in meticillin-resistant Staphylococcus aureus." Thesis, University of Portsmouth, 2013. https://researchportal.port.ac.uk/portal/en/theses/an-investigation-into-the-association-of-plasmidborne-qacab-and-antimicrobial-resistance-in-meticillinresistant-staphylococcus-aureus(49b2b0fc-936a-412a-b418-8d9d24d3b531).html.

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Meticillin-resistant Staphylococcus aureus (MRSA) is globally recognised as a major causative organism of hospital acquired infection (HAI) and continues to present many challenges for infection prevention and control. Once established within hospitals and healthcare centers, the control of spread of MRSA and therapy is difficult due to resistance to otherwise effective antimicrobials. Government initiatives in the United Kingdom (UK) have led to considerable investments in improving infection control practices, with emphasis on improving hand hygiene compliance of healthcare professionals and hospital environmental cleanliness to control the spread and limit the source of MRSA and other HAIs. This has resulted in the subsequent increase in disinfectant and antiseptic usage containing, quaternary ammonium compounds (QACs), cationic biocides such as chlorhexidine and the bisphenol ether, triclosan, for decontamination of surfaces and disinfection of skin. Thus, there is serious concern that as with antibiotic resistance, continual and intensive exposure of MRSA (and other hospital pathogens) to biocides, may result in the emergence of resistance to these agents with further detrimental consequences and substantial burden for prevention, treatment and control of hospital infections. MRSA carry a number of plasmid-borne qac genes, predominantly qacA, qacB and smr that encode resistance to commonly used antiseptics and disinfectants in hospitals, nursing homes and other healthcare establishments. The proteins encoded by qacA and qacB mediate efflux via active transport; QacA multidrug exporter mediates resistance to monovalent, divalent cationic and lipophilic antimicrobial compounds, whilst the closely related export protein QacB mediates lower levels of resistance to divalent cations. In this research a “snapshot” study of hospital strains of MRSA stored at the Hospital Infection Research Laboratory (HIRL), City Hospital, Birmingham, was carried out to determine the prevalence and distribution of qacAB in these isolates and determine a possible association between presence of these genes and biocide resistance. The intercalating dye, ethidium bromide (EtBr) is a substrate for many S. aureus multi-drug resistant (MDR) efflux pumps and was used in the present study as a marker for detection of efflux pump activity. Previous studies have reported that MRSA strains with an MIC of ≥ 64 mg/L to EtBr have qacAB, however, the present study used a lower baseline value of ≥ 32 mg/L resistance to EtBr to capture any isolates with low MICs that may have qacAB and may be missed. Initially 3,400 MRSA strains collected between October 2002 and October 2006 were screened to identify and select isolates with ≥ 32 mg/L resistance to EtBr. A second MRSA collection stored at the Antimicrobial Chemotherapy Laboratory, City Hospital, Birmingham, comprised 63 isolates that showed MICs of ≥ 64mg/L, were also included in the study. At this stage the study set (Set A) comprised 112 isolates with varying MIC to EtBr ranging from ≥ 32 mg/L to 256 mg/L. At a later date an additional 400 strains were screened from the same stored collection to include strains with lower MICs, i.e. < 32 mg/L. Thus a total of 336 isolates with varying levels of resistance to EtBr were studied. PCR was carried out on all 336 isolates for detection o qacAB, smr, qacG, qacH and qacJ to determine the presence and prevalence of the genes. Set A isolates positive for qacAB were further investigated to differentiate between qacA and qacB. Restriction digestion using the restriction enzyme Rsa1 was carried out on PCR products followed by PCR using specific primers for detection of the two genes. Urease activity and neomycin sensitivity were used as a means of basic characterization applied to all the study isolates. A select number of samples negative for qacA and qacB were typed using spa typing. Transfer studies involving, conjugation, plate mating and transformation on selected strains were carried out to attempt transfer of qacAB using the marker EtBr from a strain of MRSA with an MIC of ≥ 256 mg/L to EtBr and qacAB positive to a strain with < 32mg/L MIC to EtBr and lacking qacAB. Unfortunately, conjugation experiments were not successful in this study. Plasmid curing experiments were also carried out to demonstrate loss of plasmid through continual passaging onto selective plates. A variety of antiseptics and disinfectants are used in hospitals for prevention of HAIs. The present study was limited to carrying out minimum bactericidal concentration (MBC) determinations and MIC of four commonly used hospital biocides against randomly selected strains. The strains reflected ranges of MICs to EtBr and presence or absence of qacAB. These experiments, determined the efficacy of the biocides tested, to effectively destroy MRSA on skin and environment when used in healthcare settings. The results suggest that in the majority of strains showing high MICs to EtBr i.e. ≥ 64 mg/L, qacAB is present and thus, the mechanism of resistance to biocides may be attributed to an efflux protein pump encoded by these genes. Following restriction digestion of qacAB positive strains, with the restriction enzyme Rsa1, 81 of the 112 qacAB positive strains tested positive for qacA, i.e. 90% and 9 (11%) for qacB. The predominant prevalence of the qacA gene indicates that most of these strains are likely to be resistant to organic cationic biocides and intercalating dyes such as EtBr and acriflavine. However, the results of the MIC and MBC determinations carried out on a selection of biocides commonly used in the healthcare environment implies that the four biocides tested are likely to be 99.9% effective at killing the majority of isolates in this study set. However, five isolates demonstrated MBCs to chlorhexidine of > 32 mg/L. Chlorhexidine is a compound that is widely used in hand hygiene and surgical antisepsis products, and the results suggest that solutions containing this compound would be ineffective in removing MRSA from the hands of healthcare workers and skin sites if used. Molecular spa typing of selected samples negative for qacAB revealed that Endemic-MRSA (EMRSA) type 15 was the most frequent spa type identified in this study, followed by EMRSA-16 and EMRSA-1. Three strains identified jointly as EMRSA-3 and EMRSA-1. One strain identified as the Berlin clone. With regards to the challenges presented to infection prevention and control, MRSA has the potential to develop increased tolerance to biocides commonly used in the hospital environment, due to expression of efflux pumps, although currently there is little evidence of this. Further research is required to understand and learn of the various mechanisms of resistance, supported by adherence to control of infection strategies for prevention and spread of infections in healthcare facilities.
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Ho, Kai Lung. "Power, economy, and culture on the Mongol steppe in the Yuan era : the case of Qara Qorum /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?HUMA%202004%20HO.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 159-175). Also available in electronic version. Access restricted to campus users.
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Books on the topic "QacA"

1

Ali-Sade, Frangis. Qara Qarayev. Bakı: [s.n.], 1997.

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Ämirov, Cämşid. Qara "Volqa". Bakı: Azärbaycan Dövlät Näşrĭyyati, 1993.

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Masood, Anwar. Qata kalami. Lahore: Gora Publishers, 1996.

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Ghassan, Habbal, and Sehnaoui Mouna Bassili, eds. Qānā = Qana. [Beirut]: Muʻassasat al-Ḥarīrī, 1997.

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Bassili, Sehnaoui Mouna, and Habbali Ghassan, eds. Qānā = Qana. [Bayrūt, Lubnān]: Muʻassasat al-Ḥarīrī, 1997.

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Fazlyev, Sabit. Qara ėtap: Roman. Ȯfȯ: Kitap, 2018.

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Baku (Azerbaijan). Bakı Şähär Mädäniyyät İdaräsi., ed. Qala räsm qalereyası. Bakı: Çaşıoğlu, 2002.

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Rahi, Aslam. Karwan-e-Qaza. Lahore: Maqbool, 2000.

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Safi, Ibne. Dast-e-qaza. Delhi: Kitabvala, 1990.

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Ḥakīm, Tawfīq. Himari qala li. Cairo: Misr, 2002.

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Book chapters on the topic "QacA"

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Abakarov, Ibragim. "Aliev, Habib: Qutqussi schurqla Qada." In Kindlers Literatur Lexikon (KLL), 1–2. Stuttgart: J.B. Metzler, 2020. http://dx.doi.org/10.1007/978-3-476-05728-0_1137-1.

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Fakhimi, Ramin, and Hamidreza Validi. "Quantum Approximate Optimization Algorithm (QAOA)." In Encyclopedia of Optimization, 1–7. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-030-54621-2_854-1.

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Hamido, Omar Costa. "QAC: Quantum-Computing Aided Composition." In Quantum Computer Music, 159–95. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-13909-3_8.

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Natolski, Jan. "Eigenschaften der Probleme QTV, QSCF und QACF." In Replizierende Portfolios in der Lebensversicherung, 87–99. Wiesbaden: Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-20376-4_6.

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Natolski, Jan. "Zusammenhänge der Probleme QTV, QSCF und QACF." In Replizierende Portfolios in der Lebensversicherung, 101–19. Wiesbaden: Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-20376-4_7.

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May, Timothy. "The Conquest of Qara Khitai and Western Siberia." In The Mongol World, 137–49. London: Routledge, 2022. http://dx.doi.org/10.4324/9781315165172-12.

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Haddad, Fidaa F. "Qa’a Azraq Oasis, Strengthening Stakeholder Representation in Restoration (Jordan)." In The Wetland Book, 1–7. Dordrecht: Springer Netherlands, 2016. http://dx.doi.org/10.1007/978-94-007-6173-5_25-9.

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Haddad, Fidaa F. "Qa’a Azraq Oasis: Strengthening Stakeholder Representation in Restoration (Jordan)." In The Wetland Book, 461–67. Dordrecht: Springer Netherlands, 2018. http://dx.doi.org/10.1007/978-94-007-4001-3_25.

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Lu, Chi-Jen. "An Exact Characterization of Symmetric Functions in qAC0[2]." In Lecture Notes in Computer Science, 167–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/3-540-68535-9_20.

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McCollough, Tom. "The Synagogue at Khirbet Qana in Its Village Context." In The Synagogue in Ancient Palestine: Current Issues and Emerging Trends, 81–96. Göttingen: Vandenhoeck & Ruprecht, 2020. http://dx.doi.org/10.13109/9783666522147.81.

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Conference papers on the topic "QacA"

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Nguyen, Trang M., Van-Lien Tran, Duy-Cat Can, Quang-Thuy Ha, Ly T. Vu, and Eng-Siong Chng. "QASA." In the 3rd International Conference. New York, New York, USA: ACM Press, 2019. http://dx.doi.org/10.1145/3310986.3310999.

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Chen, Jiasi, Amitabha Ghosh, Josphat Magutt, and Mung Chiang. "QAVA." In the 8th international conference. New York, New York, USA: ACM Press, 2012. http://dx.doi.org/10.1145/2413176.2413191.

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Kim, Jinhan, Sameh Elnikety, Yuxiong He, Seung-won Hwang, and Shaolei Ren. "QACO." In the 2013 ACM Cloud and Autonomic Computing Conference. New York, New York, USA: ACM Press, 2013. http://dx.doi.org/10.1145/2494621.2494636.

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Zheng, Yudian, Jiannan Wang, Guoliang Li, Reynold Cheng, and Jianhua Feng. "QASCA." In SIGMOD/PODS'15: International Conference on Management of Data. New York, NY, USA: ACM, 2015. http://dx.doi.org/10.1145/2723372.2749430.

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Campbell, Colin, and Edward Dahl. "QAOA of the Highest Order." In 2022 IEEE 19th International Conference on Software Architecture Companion (ICSA-C). IEEE, 2022. http://dx.doi.org/10.1109/icsa-c54293.2022.00035.

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Turati, Gloria, Maurizio Ferrari Dacrema, and Paolo Cremonesi. "Feature Selection for Classification with QAOA." In 2022 IEEE International Conference on Quantum Computing and Engineering (QCE). IEEE, 2022. http://dx.doi.org/10.1109/qce53715.2022.00117.

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Chen, Yanzhu, Linghua Zhu, Nicholas J. Mayhall, Edwin Barnes, and Sophia E. Economou. "How Much Entanglement Do Quantum Optimization Algorithms Require?" In Quantum 2.0. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/quantum.2022.qm4a.2.

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ADAPT-QAOA, a novel problem-tailored version of quantum approximate optimization algorithm, speeds up convergence using entangling operators while reducing the total number of CNOTs. We explore how much entanglement is required to speed up optimization algorithms.
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Lim, Wootaek. "SpecAugment for Sound Event Detection in Domestic Environments using Ensemble of Convolutional Recurrent Neural Networks." In 4th Workshop on Detection and Classification of Acoustic Scenes and Events (DCASE 2019). New York University, 2019. http://dx.doi.org/10.33682/qacg-8m97.

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Chalupnik, Michelle, Hans Melo, Yuri Alexeev, and Alexey Galda. "Augmenting QAOA Ansatz with Multiparameter Problem-Independent Layer." In 2022 IEEE International Conference on Quantum Computing and Engineering (QCE). IEEE, 2022. http://dx.doi.org/10.1109/qce53715.2022.00028.

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Kakkar, Ashish, Jeffrey Larson, Alexey Galda, and Ruslan Shaydulin. "Characterizing Error Mitigation by Symmetry Verification in QAOA." In 2022 IEEE International Conference on Quantum Computing and Engineering (QCE). IEEE, 2022. http://dx.doi.org/10.1109/qce53715.2022.00086.

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Reports on the topic "QacA"

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Pelofske, Elijah, Andreas Baertschi, and Stephan Eidenbenz. Short-Depth QAOA circuits and Quantum Annealing on Higher-Order Ising Models. Office of Scientific and Technical Information (OSTI), June 2023. http://dx.doi.org/10.2172/1985256.

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Hutchinson, M. L., J. E. L. Corry, and R. H. Madden. A review of the impact of food processing on antimicrobial-resistant bacteria in secondary processed meats and meat products. Food Standards Agency, October 2020. http://dx.doi.org/10.46756/sci.fsa.bxn990.

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For meat and meat products, secondary processes are those that relate to the downstream of the primary chilling of carcasses. Secondary processes include maturation chilling, deboning, portioning, mincing and other operations such as thermal processing (cooking) that create fresh meat, meat preparations and ready-to-eat meat products. This review systematically identified and summarised information relating to antimicrobial resistance (AMR) during the manufacture of secondary processed meatand meat products (SPMMP). Systematic searching of eight literature databases was undertaken and the resultantpapers were appraised for relevance to AMR and SPMMP. Consideration was made that the appraisal scores, undertaken by different reviewers, were consistent. Appraisal reduced the 11,000 initially identified documents to 74, which indicated that literature relating to AMR and SPMMP was not plentiful. A wide range of laboratory methods and breakpoint values (i.e. the concentration of antimicrobial used to assess sensitivity, tolerance or resistance) were used for the isolation of AMR bacteria.The identified papers provided evidence that AMR bacteria could be routinely isolated from SPMMP. There was no evidence that either confirmed or refuted that genetic materials capable of increasing AMR in non-AMR bacteria were present unprotected (i.e. outside of a cell or a capsid) in SPMMP. Statistical analyses were not straightforward because different authors used different laboratory methodologies.However, analyses using antibiotic organised into broadly-related groups indicated that Enterobacteriaceaeresistant to third generation cephalosporins might be an area of upcoming concern in SPMMP. The effective treatment of patients infected with Enterobacteriaceaeresistant to cephalosporins are a known clinical issue. No AMR associations with geography were observed and most of the publications identified tended to be from Europe and the far east.AMR Listeria monocytogenes and lactic acid bacteria could be tolerant to cleaning and disinfection in secondary processing environments. The basis of the tolerance could be genetic (e.g. efflux pumps) or environmental (e.g. biofilm growth). Persistent, plant resident, AMR L. monocytogenes were shown by one study to be the source of final product contamination. 4 AMR genes can be present in bacterial cultures used for the manufacture of fermented SPMMP. Furthermore, there was broad evidence that AMR loci could be transferred during meat fermentation, with refrigeration temperatures curtailing transfer rates. Given the potential for AMR transfer, it may be prudent to advise food business operators (FBOs) to use fermentation starter cultures that are AMR-free or not contained within easily mobilisable genetic elements. Thermal processing was seen to be the only secondary processing stage that served as a critical control point for numbers of AMR bacteria. There were significant linkages between some AMR genes in Salmonella. Quaternary ammonium compound (QAC) resistance genes were associated with copper, tetracycline and sulphonamide resistance by virtue of co-location on the same plasmid. No evidence was found that either supported or refuted that there was any association between AMR genes and genes that encoded an altered stress response or enhanced the survival of AMR bacteria exposed to harmful environmental conditions.
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