Relevant bibliographies by topics / Horizontal transfer of resistance genes

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Academic literature on the topic 'Horizontal transfer of resistance genes'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Horizontal transfer of resistance genes"

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Lerminiaux, Nicole A., and Andrew D. S. Cameron. "Horizontal transfer of antibiotic resistance genes in clinical environments." Canadian Journal of Microbiology 65, no. 1 (January 2019): 34–44. http://dx.doi.org/10.1139/cjm-2018-0275.

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A global medical crisis is unfolding as antibiotics lose effectiveness against a growing number of bacterial pathogens. Horizontal gene transfer (HGT) contributes significantly to the rapid spread of resistance, yet the transmission dynamics of genes that confer antibiotic resistance are poorly understood. Multiple mechanisms of HGT liberate genes from normal vertical inheritance. Conjugation by plasmids, transduction by bacteriophages, and natural transformation by extracellular DNA each allow genetic material to jump between strains and species. Thus, HGT adds an important dimension to infectious disease whereby an antibiotic resistance gene (ARG) can be the agent of an outbreak by transferring resistance to multiple unrelated pathogens. Here, we review the small number of cases where HGT has been detected in clinical environments. We discuss differences and synergies between the spread of plasmid-borne and chromosomal ARGs, with a special consideration of the difficulties of detecting transduction and transformation by routine genetic diagnostics. We highlight how 11 of the top 12 priority antibiotic-resistant pathogens are known or predicted to be naturally transformable, raising the possibility that this mechanism of HGT makes significant contributions to the spread of ARGs. HGT drives the evolution of untreatable “superbugs” by concentrating ARGs together in the same cell, thus HGT must be included in strategies to prevent the emergence of resistant organisms in hospitals and other clinical settings.
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Yang, Dong, Jingfeng Wang, Zhigang Qiu, Min Jin, Zhiqiang Shen, Zhaoli Chen, Xinwei Wang, Bin Zhang, and Jun-Wen Li. "Horizontal transfer of antibiotic resistance genes in a membrane bioreactor." Journal of Biotechnology 167, no. 4 (September 2013): 441–47. http://dx.doi.org/10.1016/j.jbiotec.2013.08.004.

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Shoeb, Erum, Uzma Badar, Jameela Akhter, Hina Shams, Maria Sultana, and Maqsood A. Ansari. "Horizontal gene transfer of stress resistance genes through plasmid transport." World Journal of Microbiology and Biotechnology 28, no. 3 (September 29, 2011): 1021–25. http://dx.doi.org/10.1007/s11274-011-0900-6.

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Kleter, Gijs A., Ad A. C. M. Peijnenburg, and Henk J. M. Aarts. "Health Considerations Regarding Horizontal Transfer of Microbial Transgenes Present in Genetically Modified Crops." Journal of Biomedicine and Biotechnology 2005, no. 4 (2005): 326–52. http://dx.doi.org/10.1155/jbb.2005.326.

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The potential effects of horizontal gene transfer on human health are an important item in the safety assessment of genetically modified organisms. Horizontal gene transfer from genetically modified crops to gut microflora most likely occurs with transgenes of microbial origin. The characteristics of microbial transgenes other than antibiotic-resistance genes in market-approved genetically modified crops are reviewed. These characteristics include the microbial source, natural function, function in genetically modified crops, natural prevalence, geographical distribution, similarity to other microbial genes, known horizontal transfer activity, selective conditions and environments for horizontally transferred genes, and potential contribution to pathogenicity and virulence in humans and animals. The assessment of this set of data for each of the microbial genes reviewed does not give rise to health concerns. We recommend including the above-mentioned items into the premarket safety assessment of genetically modified crops carrying transgenes other than those reviewed in the present study.
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McInnes, Ross S., Gregory E. McCallum, Lisa E. Lamberte, and Willem van Schaik. "Horizontal transfer of antibiotic resistance genes in the human gut microbiome." Current Opinion in Microbiology 53 (February 2020): 35–43. http://dx.doi.org/10.1016/j.mib.2020.02.002.

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Zhang, Hongna, Jingbo Liu, Lei Wang, and Zhenzhen Zhai. "Glyphosate escalates horizontal transfer of conjugative plasmid harboring antibiotic resistance genes." Bioengineered 12, no. 1 (December 21, 2020): 63–69. http://dx.doi.org/10.1080/21655979.2020.1862995.

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Jia, Yuqian, Zhiqiang Wang, Dan Fang, Bingqing Yang, Ruichao Li, and Yuan Liu. "Acetaminophen promotes horizontal transfer of plasmid-borne multiple antibiotic resistance genes." Science of The Total Environment 782 (August 2021): 146916. http://dx.doi.org/10.1016/j.scitotenv.2021.146916.

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Froehlich, Barbara, Erik Holtzapple, Timothy D. Read, and June R. Scott. "Horizontal Transfer of CS1 Pilin Genes of Enterotoxigenic Escherichia coli." Journal of Bacteriology 186, no. 10 (May 15, 2004): 3230–37. http://dx.doi.org/10.1128/jb.186.10.3230-3237.2004.

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ABSTRACT CS1 is one of a limited number of serologically distinct pili found in enterotoxigenic Escherichia coli (ETEC) strains associated with disease in people. The genes for the CS1 pilus are on a large plasmid, pCoo. We show that pCoo is not self-transmissible, although our sequence determination for part of pCoo shows regions almost identical to those in the conjugative drug resistance plasmid R64. When we introduced R64 into a strain containing pCoo, we found that pCoo was transferred to a recipient strain in mating. Most of the transconjugant pCoo plasmids result from recombination with R64, leading to acquisition of functional copies of all of the R64 transfer genes. Temporary coresidence of the drug resistance plasmid R64 with pCoo leads to a permanent change in pCoo so that it is now self-transmissible. We conclude that when R64-like plasmids are transmitted to an ETEC strain containing pCoo, their recombination may allow for spread of the pCoo plasmid to other enteric bacteria.
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Basim, Huseyin, Robert E. Stall, Gerald V. Minsavage, and Jeffrey B. Jones. "Chromosomal Gene Transfer by Conjugation in the Plant Pathogen Xanthomonas axonopodis pv. vesicatoria." Phytopathology® 89, no. 11 (November 1999): 1044–49. http://dx.doi.org/10.1094/phyto.1999.89.11.1044.

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Genes for copper resistance, located on the chromosome of strain XvP26 of Xanthomonas axonopodis pv. vesicatoria, were transferred by conjugation to a recipient strain of the bacterium. The chromosomal gene transfer was verified by analyses of the genomes of donor, recipient, and putative transconjugants for plasmid profiles, by polymorphism of DNA bands obtained by digesting total genomic DNA by a rare-cutting endonuclease and pulsed-field gel electrophoresis, and by Southern hybridization with a probe containing the copper genes. Transfer of kanamycin resistance to a recipient strain, associated with Tn5 insertion into the chromosome of another strain of the bacterial spot pathogen, was also verified. The frequency of kanamycin resistance transfer to recipient was more than 75 times greater in pepper leaves than in vitro. The transfer of chromosomal sequences containing the hypersensitive reaction and pathogenicity (hrp) genes and pigmentation (pig) genes was linked with transfer of kanamycin resistance (Tn5). Horizontal transfer in planta of the chromosomal genes (i.e., cop, pig, hrp, and Tn5 sequences) among strains of X. axonopodis pv. vesicatoria means that horizontal chromosomal gene transfer is possible in nature. This type of gene transfer may explain the presence of great diversity among strains of the bacterial spot pathogen in terms of DNA polymorphism and may also explain the apparent horizontal transfer of hrp sequences among pathovars of Xanthomonas.
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Shoemaker, N. B., H. Vlamakis, K. Hayes, and A. A. Salyers. "Evidence for Extensive Resistance Gene Transfer amongBacteroides spp. and among Bacteroides and Other Genera in the Human Colon." Applied and Environmental Microbiology 67, no. 2 (February 1, 2001): 561–68. http://dx.doi.org/10.1128/aem.67.2.561-568.2001.

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ABSTRACT Transfer of antibiotic resistance genes by conjugation is thought to play an important role in the spread of resistance. Yet virtually no information is available about the extent to which such horizontal transfers occur in natural settings. In this paper, we show that conjugal gene transfer has made a major contribution to increased antibiotic resistance in Bacteroides species, a numerically predominant group of human colonic bacteria. Over the past 3 decades, carriage of the tetracycline resistance gene, tetQ, has increased from about 30% to more than 80% of strains. Alleles oftetQ in different Bacteroides species, with one exception, were 96 to 100% identical at the DNA sequence level, as expected if horizontal gene transfer was responsible for their spread. Southern blot analyses showed further that transfer of tetQwas mediated by a conjugative transposon (CTn) of the CTnDOT type. Carriage of two erythromycin resistance genes, ermF andermG, rose from <2 to 23% and accounted for about 70% of the total erythromycin resistances observed. Carriage oftetQ and the erm genes was the same in isolates taken from healthy people with no recent history of antibiotic use as in isolates obtained from patients with Bacteroidesinfections. This finding indicates that resistance transfer is occurring in the community and not just in clinical environments. The high percentage of strains that are carrying these resistance genes in people who are not taking antibiotics is consistent with the hypothesis that once acquired, these resistance genes are stably maintained in the absence of antibiotic selection. Six recently isolated strains carriedermB genes. Two were identical to erm(B)-P fromClostridium perfringens, and the other four had only one to three mismatches. The nine strains with ermG genes had DNA sequences that were more than 99% identical to the ermG ofBacillus sphaericus. Evidently, there is a genetic conduit open between gram-positive bacteria, including bacteria that only pass through the human colon, and the gram-negative Bacteroidesspecies. Our results support the hypothesis that extensive gene transfer occurs among bacteria in the human colon, both within the genus Bacteroides and among Bacteroides species and gram-positive bacteria.
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Dissertations / Theses on the topic "Horizontal transfer of resistance genes"

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Seaman, Paul F. "Development and horizontal gene transfer of triclosan resistance in Staphylococcus aureus." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54591/.

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Staphylococcus aureus is a major cause of hospital-acquired infections that are becoming increasingly difficult to treat because of the organism's ability to acquire resistance to current antimicrobial agents. Particular attention has been focussed on the evolution of methicillin-resistant S. aureus (MRSA) - strains of S. aureus that are, in some cases, resistant to almost all known antibiotic classes. One method used to control the spread of MRSA has been the use of topical washes that include triclosan, a potent antimicrobial with particular activity against Gram-positive organisms. Triclosan has traditionally been classed as a biocide and is also used in a broad spectrum of consumer healthcare products, including toothpastes and deodorants. It has also been used to prevent bacterial growth through incorporation into plastics used during food preparation or sutures used to close wounds following surgery. However, in 1991 resistance to triclosan was reported and was described to transfer in association with mupirocin resistance. This was followed by reports that resistance was present in 7.5% of S. aureus isolates and that MRSA was less susceptible to triclosan than methicillin- sensitive S. aureus (MSSA). It later emerged that, contrary to previous thinking, triclosan targets a specific bacterial protein, Fabl. We aimed to characterize the development of reduced susceptibility to triclosan in MSSA and MRSA and to identify whether triclosan does have a single, specific target. We also set out to elucidate the potential for triclosan resistance to be disseminated by horizontal gene transfer (HGT). By using extensive microbiological and genetic techniques we found that S. aureus can evolve reduced susceptibility to triclosan through spontaneous mutation. MICs of 1-4 mg/L were achieved by a C284T mutation offabl, compared to wild-type MICs of -0.03 mg/L. However, reduced susceptibility was also observed in non-fabl mutants, implying that other mechanisms of resistance are available (and that triclosan has targets other than Fabl). We have shown that triclosan induces the leakage of potassium ions from cells, an indication that triclosan targets the cytoplasmic membrane. However, whilst reduced susceptibility to triclosan did confer reduced susceptibility to the lethal effects of 7.5 mg/L triclosan, this effect was ameliorated by higher concentrations of triclosan. Indeed, in-use concentrations of the commercial preparation of triclosan, Irgacide LP 10, are equally active against reduced susceptibility S. aureus and wild-type. Therefore, the evolution of reduced-susceptibility to triclosan is of ambiguous clinical significance. We found that spontaneous mutation to reduced susceptibility was not associated with a significant fitness cost, augmenting its potential for emergence in nature. Evolution of reduced susceptibility did not confer co-resistance to other antimicrobials and MRSA and MSSA strains were equally susceptible. An assessment of commensal S. aureus carried amongst the student population of Cardiff revealed that reduced susceptibility to triclosan is rare in this population. However, coagulase-negative staphylococci (CoNS) showed consistently higher MICs for triclosan and may represent an amenable reservoir of resistance. There was no indication that mupirocin and triclosan resistance have co-transferred in the past. Indeed, there appeared to be no relationship between resistance to either of these compounds in S. aureus. Reduced susceptibility to triclosan could not be disseminated amongst 5". aureus, or related Gram-positive bacteria by transduction, conjugation or transformation. Importantly, during the course of this work we discovered that triclosan could select for S. aureus small-colony variants (SCVs) that were coincidently resistant to gentamicin and penicillin. These were slow growing and illustrated the typical SCV phenotype. SCVs were more readily transformable than wild-type cells and may represent an enduring reservoir of resistance determinants. In conclusion, we found that S. aureus could develop reduced susceptibility to triclosan by spontaneous mutation or the evolution of SCVs. However, the level of resistance is of ambiguous significance. We propose that triclosan does target Fabl, but also has other cellular targets, particularly at higher concentrations. Whilst the evolution of reduced susceptibility and the occurrence of SCVs should be monitored these should not preclude the use of triclosan as part of infection control procedures. However, to reduce the opportunities for resistance, infection control procedures should not rely upon a single antimicrobial to provide the panacea for nosocomial infections.
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Serfiotis-Mitsa, Dimitra. "Biophysical and structural studies of the antirestriction proteins ArdA and KlcA." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4358.

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Gene orf18, which is situated in the conjugative transposon Tn916 from the bacterial pathogen Enterococcus faecalis, encodes a putative ArdA (alleviation of restriction of DNA) protein. ArdA from Tn916 may be responsible for the apparent immunity of the transposon to DNA restriction and modification (R/M) systems and for ensuring that the transposon has a broad host range. The orf18 gene was engineered for overexpression in Escherichia coli and the recombinant ArdA protein was purified to homogeneity. Biophysical characterisation of ArdA demonstrated tight association between ArdA and the M.EcoKI. Also, ArdA was shown to efficiently inhibit restriction and modification by all four major classes of Type I R/M enzymes in vivo. Thus, ArdA can overcome the restriction barrier following conjugation and so helps to increase the spread of antibiotic resistance genes by horizontal gene transfer. The amino acid sequence of KlcA, from the incompatibility plasmid pBP136 from Bordetella pertussis, showed a high degree of similarity with the antirestriction protein ArdB from the IncN plasmid pKM101. In this study the solution structure of KlcA was solved with high-resolution NMR and its antirestriction function demonstrated. The structure of KlcA showed a rigid globular molecule with a novel fold. No antimodification function was observed for KlcA in vivo and the antirestriction function of KlcA has been successfully shown in vivo but not in vitro. Because no direct binding of KlcA to EcoKI was observed in vitro, the mechanism of the endonuclease blocking was assumed to be different from that of ArdA. Preliminary experiments including coimmunoprecipitation assays were conducted in order to elucidate the antirestriction mechanism of KlcA.
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Byrne-Bailey, Kathryne Greta. "Bacterial antibiotic resistance and horizontal gene transfer in slurries and slurry amended agricultural soils." Thesis, University of Warwick, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439746.

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Carrera, Sandra Garcés. "Virulence of Mayetiola destructor (Say) field populations in the Great Plains and levanase/inulase-like genes in the Hessian fly genome." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16873.

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Doctor of Philosophy
Department of Entomology
Ming-Shun Chen
C. Michael Smith
The Hessian fly, Mayetiola destructor (Say), is a major pest of wheat, and is controlled mainly through deploying fly-resistant wheat cultivars. This study investigated five M. destructor populations collected from Texas, Louisiana, and Oklahoma, where infestation by Hessian fly has been high in recent years. Eight resistance genes including H12, H13, H17, H18, H22, H25, H26, and Hdic, were found to be highly effective against all tested M. destructor populations in this region, conferring resistance to 80% or more of plants containing one of these resistant genes. The frequency of biotypes virulent to resistant genes ranged from 0 to 45%. A logistic regression model was established to predict biotype frequencies based on the correlation between the percentages of susceptible plants obtained in a virulence test. In addition to the virulence test, the log-odds of virulent biotype frequencies were determined by a traditional approach to predict the logistic regression model. Characterization of a bacterial artificial chromosome (BAC) clone identified a gene encoding a protein with sequence similarity to bacterial levanases. Blast searching with the levanase-like protein identified 14 levanase/inulase-like genes or gene fragments. In this study, we determined the expression levels of these genes in different developmental stages and different tissues of 3-d old larvae of M. destructor. Sequence analysis revealed that six genes encode full length proteins, three were truncated at the 5’ end, and five truncated at the 3’ end. Sequences of putative proteins showed approximately 42% similarities to bacterial levanases or inulases, and 36% similarity to fungal levanases or inulases. No sequence similarities were found with any known animal or plant proteins. Comparative analysis of sequences among 14 levanase/inulase-like genes revealed that positions for intron/exon boundaries are conserved among different genes even though the length of each intron and exon varied among different genes. The expression patterns of the levanase/inulase-like genes were different among developmental stages and larval tissues of M. destructor. Interestingly, three genes presented alternative splicing bands in different developmental stages, and two genes exhibited splicing bands in different tissues of 3 d old M. destructor. This study would be useful for future studies of the characterization and function of levanase/inulase-like genes of these enzymes in plant-insect interactions.
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Tolba, Sahar T. M. "Distribution of streptomycin resistance and biosynthesis genes in streptomycetes recovered from different soil sites and the role of horizontal gene transfer in their dissemination." Thesis, University of Warwick, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408239.

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Woloszczuk, Kyra. "pCF10 MEDIATES INTERSPECIES DISSEMINATION OF ANTIBIOTIC RESISTANCE DETERMINANTS IN MIXED SPECIES BIOFILMS." Master's thesis, Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/390993.

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Biomedical Sciences
M.S.
Enterococcus faecalis is a commensal bacterium, which upon acquisition of virulence factors on mobile genetic elements can cause sepsis, urinary tract infections and endocarditis. E. faecalis isolates can be multi-drug resistant and have been implicated in the dissemination of antibiotic resistance genes to other genera. Although the host range of pheromone inducible conjugative plasmids is restricted to Enterococci, they often carry transposons, which are capable of transposing into the chromosome of other genera. The plasmid pCF10 contains the antibiotic resistance gene tetM on a conjugative transposon Tn925. Tn925 is a Tn916-like plasmid and is capable of pCF10-independent conjugative transfer to multiple bacterial species at low levels. Biofilms are communities of bacteria growing within a matrix. In biofilms, bacteria are more difficult to kill because of their lower susceptibility to antibiotics. In hospital settings, biofilms can grow on medically implanted devices, catheters or even human tissue. In mixed species biofilms, antibiotic resistances are able to be transferred through horizontal gene transfer from E. faecalis to other bacterial species. In mixed species biofilms, it has been show that Tn925 can transpose into S. aureus at rates of 10-8 by Ella Massie Schuh. Using static mixed species biofilms, the transfer of tetM from E. faecalis to S. aureus was studied, hoping to better understand the underlying mechanisms. The goal of these studies was to determine if residence on pCF10 increased the transfer frequency of Tn925 in mixed species biofilms. Mixed species biofilms containing E. faecalis (pCF10) and S. aureus (pALC2073aPSM) were established and pCF10 conjugation was induced with pheromone cCF10. Transfer of Tn925::tetM to S. aureus was detected at a rate of approx. 10-8. No transfer was detected when Tn925 was present in the E. faecalis chromosome (lower limit of approx. 10-10). The increased transfer frequency was dependent on induction with cCF10. These results suggest that pCF10 can disseminate Tn925::tetM to S. aureus and the presence of the conjugative transposon on the plasmid increases its transfer rate. Previous observations in the laboratory show that in some circumstances, E. faecalis would be erythromycin resistant. To understand how this resistance was occurring, we investigated whether retrotransfer was occurring in mixed species biofilms. Retrotransfer is the transfer of genes from the recipient cell, back into the donor cell. For this experimental design, mixed species biofilms were forms erythromycin resistant E. faecalis transconjugants were selected for. While we successfully selected erythromycin resistant E. faecalis, upon gene sequencing it was shown that retrotransfer of the ermC gene was not occurring. Instead, these erythromycin resistant E. faecalis were spontaneous mutants. While transfer was not detected, this model leads to the hypothesis that induction of conjugation may increase the rates of spontaneous mutations of E. faecalis in biofilms.
Temple University--Theses
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Ray, Melissa D. "CHARACTERIZATION OF TRANSFER OF THE MOBILE GENOMIC ISLAND ENCODING METHICILLIN RESISTANCE AMONG STAPHYLOCOCCI." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3946.

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The gene encoding methicillin resistance in Staphylococcus aureus (MRSA) is carried in the chromosome on a large genomic island called SCCmec and is always inserted at the att site within orfX. SCCmec has been designated a mobile genetic element but a mechanism by which it moves among different strains and species of staphylococci has never been demonstrated. This work shows that bacteriophage 80α is capable of transducing SCCmec into a recipient cell, after which it can integrate into the bacterial chromosome via homologous recombination. More importantly, this work characterizes a conjugative mechanism of SCCmec transfer. Results demonstrate the capture of a 30.8 kb SCCmec element on a conjugative plasmid for the first time, its transfer into both S. aureus and S. epidermidis recipients, and its excision from the plasmid with insertion in the orfX att site in recipients. The element was integrated into the plasmid by recombination between IS elements invariably present on all SCCmec types and pGO1/pSK41-like conjugative plasmids. These data explain the movement of SCCmec from reservoirs in commensal coagulase-negative staphylococci into different Staphylococcus aureus lineages using a ubiquitous conjugative plasmid that can transfer among staphylococci of different species and, thus, describes a mechanism for the environmental dissemination of methicillin resistance in nature.
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Albaaj, Mohammed. "Diversity of β-Lactamase Genes in Gram-Negative Soil Bacteria from Northwest Ohio." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1566553116919146.

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Faucher, Marion. "Le transfert horizontal de gènes chez les mycoplasmes : de l'acquisition de l'antibiorésistance à la dynamique des génomes." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0117/document.

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Les mycoplasmes sont des bactéries atypiques, dépourvues de paroi et souvent considérées comme des cellules minimales du fait de la taille réduite de leur génome. De nombreuses espèces sont pathogènes et ont un impact économique important dans les filières d'élevage, notamment pour les ruminants. Les mycoplasmes n'échappent pas au phénomène mondial de la résistance aux antibiotiques. Contrairement à la plupart des autres bactéries, les mycoplasmes ne contiennent pas de plasmides conjugatifs souvent incriminés dans la dissémination horizontale de gènes de résistance, la base moléculaire principalement décrite étant la mutation chromosomique des gènes cibles. De façon générale, le transfert horizontal de gènes (HGT) chez les mycoplasmes a longtemps été sous-estimé. Récemment, deux mécanismes de HGT ont été décrits chez Mycoplasma agalactiae : le transfert d'élément conjugatif et intégratif (ICE), et le transfert non-conventionnel de régions chromosomiques par conjugaison appelé MCT (Mycoplasma Chromosomal Transfer). Nos travaux se sont attachés à explorer ce dernier mécanisme et à évaluer son impact sur l'acquisition de la résistance aux antibiotiques. Une analyse de génomique comparative a été conduite à partir du séquençage de nombreux mutants spontanément résistants et de transconjugants générés par des expériences de mating et sélectionnés pour leur résistance. Nos résultats montrent que le MCT conduit de façon distributive au transfert simultané de nombreux fragments. En une seule étape de conjugaison impliquant deux souches, ce phénomène génère une population variée de génomes hautement mosaïques. Il accélère la dissémination de l'antibiorésistance, permettant l'acquisition de plusieurs mutations distantes associées à la résistance en un seul événement. De par les multiples possibilités de réassemblage génomique qu'il produit, le MCT pourrait avoir des conséquences importantes sur d'autres processus adaptatifs comme la virulence ou la spécificité d'hôte. Enfin, les modalités distributives et l’ampleur du MCT expliquent l'origine des transferts de gènes précédemment détectés in silico entre de nombreux mycoplasmes. Ce phénomène pourrait donc avoir eu des répercussions importantes sur l'évolution de ces bactéries minimales et être un facteur clé de leur persistance et virulence actuelles
Mycoplasmas are wall-less bacteria often portrayed as minimal cells because of their reduced genomes. Several species are pathogenic and have a significant economic impact on livestock production, especially for ruminants. Mycoplasmas are also concerned with the worldwide increase in antibiotic resistance. In contrast to the majority of bacteria, these simple bacteria are deprived of conjugative plasmids that are frequently implicated in the horizontal dissemination of resistance genes: in mycoplasmas antibiotic resistance mainly relies on chromosomal mutations in target genes. In Mycoplasmas, the horizontal gene transfer (HGT) has long been underestimated. Recently, two conjugative mechanisms of HGT were described in Mycoplasma agalactiae: the transfer of an integrative and conjugative element (ICE), and the unconventional transfer of chromosomal DNA further designed by “MCT” for Mycoplasma Chromosomal Transfer. Our current study focused on exploring MCT mechanisms and on estimating its impact on antibiotic resistance dissemination. Comparative genomic analyses were performed from the sequencing (i) of spontaneous resistant mutants and (ii) of transconjugants selected by mating experiments and selected based on their resistance. Data revealed that MCT generated the simultaneous transfer of multiple, unrelated donor-fragments following a distributive process. In one conjugative step involving two strains, MCT generated a variety of highly mosaic genomes. This phenomenon was also shown to accelerate the dissemination of antibiotic resistance, by allowing in one step the acquisition of multiple and dispersed mutations associated with resistance. Due to the limitless ability of this phenomenon in reshuffling genomes, MCT may offer a valuable contribution in other adaptive processes such as virulence or host specificity. Finally, the distributive nature and the extent of MCT explain the origin of genes transfers detected in silico in several mycoplasma species. MCT is certainly a major player in the evolution of these minimal bacteria and a key factor of their persistence and virulence
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Balsalobre, Livia Carminato. "Resistência a tetraciclinas em isolados clínicos e ambientais de Escherichia coli, Klebsiella pneumoniae e Aeromonas spp.: identificação e mapeamento do ambiente genético de genes tet." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/6/6135/tde-11102014-091855/.

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Introdução. A resistência bacteriana a antibióticos é aceita como um dos maiores problemas de saúde pública. As tetraciclinas são antibióticos de amplo espectro, e após seu uso indiscriminado observou-se o surgimento de bactérias resistentes, levando médicos e veterinários a diminuírem seu uso. Objetivos. Verificar o perfil de sensibilidade a tetraciclinas em isolados clínicos e ambientais de Escherichia coli, Klebsiella pneumoniae e Aeromonas spp., bem como pesquisar os principais genes tet associados à resistência a esta classe de antibióticos e determinar a potencial forma de disseminação destes genes através da caracterização de seu ambiente genético. Material e Métodos. Os perfis de sensibilidade à tetraciclina (TET), doxiciclina (DOX), minociclina (MIN) e tigeciclina (TGC) de 572 isolados foram obtidos através das técnicas de Disco-Difusão e Concentração Inibitória Mínima. Os isolados não-sensíveis à tetraciclina foram submetidos a reações de PCR para pesquisa de grupos Inc, genes tet e para a caracterização de seu ambiente genético pela pesquisa das integrases de classes 1, 2, 3 e 4, e dos elementos genéticos móveis Tn1721, IS26, Tn10 e ISAS5. Perfis de similaridade genética dos isolados foram obtidos através das técnicas de ERIC-PCR e PFGE. Após análise destes resultados 33 cepas foram selecionadas para as técnicas de S1-PFGE e transformação. Resultados. A partir dos 572 isolados 18,5 por cento foram resistentes à TET, 13,5 por cento à DOX, 8 por cento à MIN e nenhum à TGC. Vinte e dois por cento dos isolados clínicos e 16,3 por cento ambientais foram resistentes à TET. Os genes codificadores de bomba de efluxo tet(A), tet(B), tet(C), tet(D) e tet(E), foram observados em 25,5 por cento , 33 por cento , 6,5 por cento , 18,9 por cento e 23,5 por cento dos isolados, respectivamente. Noventa e cinco por cento, 100 por cento , 100 por cento e 4,5 por cento das cepas carreando o gene tet(A), tet(B), tet(D) e tet(E), foram não-sensíveis à DOX, nesta ordem. Resistência à MIN foi observada em 4,2 por cento , 78,8 por cento e 100 por cento dos isolados carreando tet(A), tet(B) e tet(D), respectivamente. O gene tet(A) estava associado a Tn1721, tet(B) à Tn10 e tet(C) e tet(D) à IS26. Nenhuma das integrases pesquisadas estavam associadas aos genes tet detectados. Os grupos IncF, IncFIB e IncA/C foram observados em 54,8 por cento , 41,1 por cento e 28,7 por cento dos isolados, respectivamente. Uma cepa de Aeromonas spp. carreava um plasmídio do grupo IncP. Através dos perfis de similaridade genética foi observado que dentre os isolados hospitalares de K. pneumoniae houve a ocorrência de perfis genéticos idênticos, no entanto nos demais isolados do estudo os perfis genéticos observados eram distintos. Das 33 cepas selecionadas para os experimentos de linearização plasmidial e de transformação, 8 foram transformadas com sucesso, nas quais foi observada a presença dos genes tet em plasmídios. Conclusões. Uma baixa porcentagem de resistência à TET foi detectada. Verificou-se que a TGC foi a tetraciclina mais ativa, seguida da MIN. Os genes tet(A) e tet(B) foram os mais prevalentes. Todas as cepas carreando tet(B) e tet(D) foram não-sensíveis a DOX e MIN. Plasmídios dos grupos IncF, FIB e A/C foram os mais detectados neste estudo. Os resultados sugerem que os genes tet(A), (B), (C) e (D) são disseminados por meio de plasmídios e estão associados aos transposons Tn1721, IS10 e IS26. Estudos adicionais com isolados mais recentes e outros gêneros bacterianos são necessários, para contribuir com informações da resistência bacteriana a tetraciclinas.
Introduction. The antibiotic resistance is accepted as one of the major problems for public health. Tetracyclines are broad spectrum antibiotics, and its indiscriminate use promoted the emergence of resistant bacteria, leading physicians and veterinarians to decrease its use. Objectives. Verify the susceptibility of clinical and environmental isolates of Escherichia coli, Klebsiella pneumoniae and Aeromonas spp. to tetracyclines, and also search for the main tet genes associated with resistance to these antibiotics and determine the potential mechanism of tet genes dissemination by characterizing their genetic context. Material and Methods. Disk-Diffusion and Minimum Inhibitory Concentration tests were carried out in 572 isolates using tetracycline (TET), doxycycline (DOX), minocycline (MIN) and tigecycline (TGC). PCR was carried out in TET non-susceptible isolates for the detection of Inc groups, tet genes and its genetic context determination through the search of classes 1, 2, 3, and 4 integrases, and Tn1721, Tn10, IS26 and ISAS5 mobile genetic elements. Genetic similarities patterns were determined by ERIC-PCR and PFGE techniques. After analyzing the results 33 strains were selected for the S1-PFGE and transformation experiments. Results. From 572 isolates, 18.5 per cent were TET-resistant, 13.5 per cent DOX-resistant, 8 per cent MIN-resistant and none resistant to TGC. Twenty-two per cent and 16.3 per cent of clinical and environmental isolates were TET-resistant, in that order. Genes tet(A), tet(B), tet(C), tet(D) and tet(E), coding for efflux pump mechanism, were found in 25.5 per cent , 33 per cent , 6.5 per cent , 18.9 per cent and 23.5 per cent of the isolates, respectively. Ninety-five per cent, 100 per cent , 100 per cent and 4.5 per cent of the isolates carrying tet(A), tet(B), tet(D) and tet(E) were non-susceptible to DOX, respectively. Resistance to MIN was observed in 4.2 per cent , 78.8 per cent and 100 per cent of isolates carrying tet(A), tet(B) and tet(D), in that order. The gene tet(A) was associated with Tn1721, tet(B) with Tn10, and tet(C) and (D) with IS26. None of the searched integrases were associated with the tet genes detected. Groups IncF, IncFIB and IncA/C were respectively observed in 54.8 per cent , 41.1 per cent and 28.7 per cent of the isolates. One Aeromonas spp. was carrying an IncP plasmid. The genetic similarities patterns demonstrated that there were identical genetic patterns among the hospital K. pneumoniae isolates, however all the remaining isolates possessed distinct genetic patterns. Of the 33 strains selected for plasmid linearization and transformation experiments, 8 were successfully transformed, in which the presence of tet genes in plasmids were observed. Conclusions. A low level of tetracycline resistance was detected. TGC was the most active tested antibiotic, followed by MIN. Genes tet(A) and tet(B) were the most prevalent among the isolates. All strains carrying tet(B) and tet(D) were non-susceptible to DOX and MIN. Groups IncF, IncFIB and IncA/C were the most detected in this study. The results suggest that tet(A), (B), (C) and (D) are disseminated by plasmids and are associated with Tn1721, Tn10 and IS26. Additional studies assembling recent isolates and other genera are necessary in order to contribute with information about the bacteria resistance to tetracyclines.
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Books on the topic "Horizontal transfer of resistance genes"

1

Michael, Syvanen, and Kado Clarence I, eds. Horizontal gene transfer. 2nd ed. San Diego, Calif: Academic Press, 2002.

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B, Levy Stuart, Novick Richard P. 1932-, Cold Spring Harbor Laboratory, United States. Environmental Protection Agency., and National Science Foundation (U.S.), eds. Antibiotic resistance genes: Ecology, transfer, and expression. Cold Spring Harbor, N.Y: Cold Spring Harbor Laboratory, 1986.

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Kado, Clarence I., and Michael Syvanen. Horizontal Gene Transfer, Second Edition. Academic Press, 2002.

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Kado, Clarence I., and Michael Syvanen. Horizontal Gene Transfer, Second Edition. 2nd ed. Academic Press, 2002.

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Sun, Dongchang, Katy Jeannot, Yonghong Xiao, and Charles W. Knapp, eds. Horizontal Gene Transfer Mediated Multidrug Resistance: A Global Crisis. Frontiers Media SA, 2019. http://dx.doi.org/10.3389/978-2-88963-157-5.

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Knapp, Charles W. Horizontal Gene Transfer Mediated Multidrug Resistance: A Global Crisis, 2nd Edition. Edited by Dongchang Sun, Katy Jeannot, and Yonghong Xiao. Frontiers Media SA, 2020. http://dx.doi.org/10.3389/978-2-88963-880-2.

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Levy, Stuart B. Antibiotic Resistance Genes: Ecology, Transfer, and Expression (Banbury Report) (Banbury Report). Cold Spring Harbor Laboratory Pr, 1987.

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Bertino, J. R., ed. Marrow Protection: Transduction of Hematopoietic Cells with Drug Resistance Genes. Karger, 1999.

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Zhao, Lei. Transfer of genes conferring resistance to the pathogen Phoma lingam from Brassica juncea to Brassica oleracea by asymmetric somatic hybridization. 1992.

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Kirchman, David L. Genomes and meta-omics for microbes. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789406.003.0005.

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The sequencing of entire genomes of microbes grown in pure cultures is now routine. The sequence data from cultivated microbes have provided insights into these microbes and their uncultivated relatives. Sequencing studies have found that bacterial genomes range from 0.18 Mb (intracellular symbiont) to 13 Mb (a soil bacterium), whereas genomes of eukaryotes are much bigger. Genomes from eukaryotes and prokaryotes are organized quite differently. While bacteria and their small genomes often grow faster than eukaryotes, there is no correlation between genome size and growth rates among the bacteria examined so far. Genomic studies have also highlighted the importance of genes exchanged (“horizontal gene transfer”) between organisms, seemingly unrelated, as defined by rRNA gene sequences. Microbial ecologists use metagenomics to sequence all microbes in a community. This approach has revealed unsuspected physiological processes in microbes, such as the occurrence of a light-driven proton pump, rhodopsin, in bacteria (dubbed proteorhodopsin). Genomes from single cells isolated by flow cytometry have also provided insights about the ecophysiology of both bacteria and protists. Oligotrophic bacteria have streamlined genomes, which are usually small but with a high fraction of genomic material devoted to protein-encoding genes, and few transcriptional control mechanisms. The study of all transcripts from a natural community, metatranscriptomics, has been informative about the response of eukaryotes as well as bacteria to changing environmental conditions.
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Book chapters on the topic "Horizontal transfer of resistance genes"

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Barlow, Miriam. "What Antimicrobial Resistance Has Taught Us About Horizontal Gene Transfer." In Horizontal Gene Transfer, 397–411. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60327-853-9_23.

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Golz, Julia Carolin, and Kerstin Stingl. "Natural Competence and Horizontal Gene Transfer in Campylobacter." In Current Topics in Microbiology and Immunology, 265–92. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-65481-8_10.

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AbstractThermophilic Campylobacter, in particular Campylobacter jejuni, C. coli and C. lari are the main relevant Campylobacter species for human infections. Due to their high capacity of genetic exchange by horizontal gene transfer (HGT), rapid adaptation to changing environmental and host conditions contribute to successful spreading and persistence of these foodborne pathogens. However, extensive HGT can exert dangerous side effects for the bacterium, such as the incorporation of gene fragments leading to disturbed gene functions. Here we discuss mechanisms of HGT, notably natural transformation, conjugation and bacteriophage transduction and limiting regulatory strategies of gene transfer. In particular, we summarize the current knowledge on how the DNA macromolecule is exchanged between single cells. Mechanisms to stimulate and to limit HGT obviously coevolved and maintained an optimal balance. Chromosomal rearrangements and incorporation of harmful mutations are risk factors for survival and can result in drastic loss of fitness. In Campylobacter, the restricted recognition and preferential uptake of free DNA from relatives are mediated by a short methylated DNA pattern and not by a classical DNA uptake sequence as found in other bacteria. A class two CRISPR-Cas system is present but also other DNases and restriction–modification systems appear to be important for Campylobacter genome integrity. Several lytic and integrated bacteriophages have been identified, which contribute to genome diversity. Furthermore, we focus on the impact of gene transfer on the spread of antibiotic resistance genes (resistome) and persistence factors. We discuss remaining open questions in the HGT field, supposed to be answered in the future by current technologies like whole-genome sequencing and single-cell approaches.
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Juhas, Mario. "Genomic Islands and the Evolution of Multidrug-Resistant Bacteria." In Horizontal Gene Transfer, 143–53. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-21862-1_4.

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Villa, T. G., L. Feijoo-Siota, JL R. Rama, A. Sánchez-Pérez, and M. Viñas. "Horizontal Gene Transfer Between Bacteriophages and Bacteria: Antibiotic Resistances and Toxin Production." In Horizontal Gene Transfer, 97–142. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-21862-1_3.

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Yerrapragada, Shailaja, Janet L. Siefert, and George E. Fox. "Horizontal Gene Transfer in Cyanobacterial Signature Genes." In Horizontal Gene Transfer, 339–66. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60327-853-9_20.

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Ramírez-Bahena, Martha-Helena, Alvaro Peix, and Encarna Velázquez. "The Rhizobiaceae Bacteria Transferring Genes to Higher Plants." In Horizontal Gene Transfer, 269–89. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-21862-1_11.

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Budak-Alpdogan, Tulin, and Joseph R. Bertino. "Chemoprotection by Transfer of Resistance Genes." In Gene Therapy of Cancer, 661–704. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-561-9_34.

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Berg, K. "The Cholesteryl Ester Transfer Protein (CETP) Locus and Protection Against Atherosclerosis." In Genes and Resistance to Disease, 51–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-56947-0_6.

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Tian, Chang Fu, and J. Peter W. Young. "Evolution of Symbiosis Genes: Vertical and Horizontal Gene Transfer." In Ecology and Evolution of Rhizobia, 145–52. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9555-1_6.

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Martinez, Elena, Steven Djordjevic, H. W. Stokes, and Piklu Roy Chowdhury. "Mobilized Integrons: Team Players in the Spread of Antibiotic Resistance Genes." In Lateral Gene Transfer in Evolution, 79–103. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-7780-8_4.

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Conference papers on the topic "Horizontal transfer of resistance genes"

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Maia, Luciana Furlaneto, Márcia Regina Terra, and Márcia Cristina Furlaneto. "Horizontal Transfer of Vancomycin Resistance Gene From Enterococcus Sp. in Milk." In XII Latin American Congress on Food Microbiology and Hygiene. São Paulo: Editora Edgard Blücher, 2014. http://dx.doi.org/10.5151/foodsci-microal-101.

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Konstantinov, Yu M. "HORIZONTAL GENE TRANSFER INTO PLANT MITOCHONDRIA IN VIVO AND IN EXPERIMENTS." In The All-Russian Scientific Conference with International Participation and Schools of Young Scientists "Mechanisms of resistance of plants and microorganisms to unfavorable environmental". SIPPB SB RAS, 2018. http://dx.doi.org/10.31255/978-5-94797-319-8-1439-1440.

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REGUILLOT, F., L. WITTE, J. LIENHARD, and M. PONIEWSKI. "Pool boiling on a large horizontal flat resistance heater." In 28th National Heat Transfer Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1992. http://dx.doi.org/10.2514/6.1992-4050.

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"Transfer of rice resistance genes to blast using DNA markers." In Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Novosibirsk ICG SB RAS 2021, 2021. http://dx.doi.org/10.18699/plantgen2021-109.

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Rohrbach, Eric, and Lanbo Liu. "Simulation of 2D Heat Transfer in a Horizontal Plane with Thermal Resistance-Capacitance Model." In The 2nd World Congress on Mechanical, Chemical, and Material Engineering. Avestia Publishing, 2016. http://dx.doi.org/10.11159/htff16.140.

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Baymiev, An Kh, A. A. Vladimirova, E. S. Akimova, I. S. Koryakov, and Al Kh Baymiev. "High activity of horizontal gene transfer in nodule bacteria as a strategy for interaction with legumes." In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.038.

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The contribution of the legume plant to the formation of the genetic diversity of nodule bacteria and its effect on the activity of horizontal transfer of symbiotic genes in rhizospheric bacteria is studied.
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Jia, Li, and Dongmei Wu. "Condensating Heat Transfer of Mixture Gases Across a Horizontal Tube." In ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference collocated with the ASME 2007 InterPACK Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ht2007-32667.

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This paper combined modified film model and Nusselt’s condensation theory and studies convective condensation heat transfer on a horizontal tube across which moist mixed gas flows horizontally at a certain speed. A theoretical model allowing for gas boundary layer separation was set up and how the liquid film flows and the heat transfers on the tube were presented. The effects of flowing direction on condensation heat transfer are discussed. Results predict that the condensate is so thin that the liquid phase heat resistance can be ignored.
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Zhang, Bo, Jianqiang Shan, and Jing Jiang. "Numerical Analysis of Supercritical Water Heat Transfer in Horizontal Circular Tube." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75411.

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CANDU supercritical water reactor (SCWR) offers advantages in the areas of sustainability, economics, safety and reliability and proliferation resistance. However, there is still a big deficiency in understanding and prediction of heat transfer behaviour in supercritical fluids. In this paper, heat transfer is numerically investigated on supercritical water for three-dimensional horizontal flows. Three ε-type turbulence models are tested and the numerical results are compared with experimental data. Based on the result, the standard k-ε turbulence model with enhanced wall treatment is recommended. The effect of the buoyancy and heat transfer deterioration is also analyzed, and the criteria for onset of buoyancy effects is evaluated. The quantity Gr/Re2.7 recommended by Jackson et al. (1975) gives a capacity to predict the buoyancy.
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Hao, Tingting, Huiwen Yu, Xuehu Ma, and Zhong Lan. "Heat Transfer Characteristics of Horizontal Nano-Structured Oscillating Heat Pipes." In ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/mnhmt2019-4100.

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Abstract Working fluid in the oscillating heat pipe (OHP) with low turn number (&lt; 9) positioned in the horizontal heat mode could not easily backflow to the evaporator due to the absence of gravity. In this paper, copper OHP with superhydrophilic nano-structured inner surface by introducing additional capillary force was investigated through the visualization and thermal experiments. OHPs with 6 turns, charged with pure water as the working fluid, were fabricated with copper, and nano-structured inner surface and tested for comparison. Contact angles of water on the copper and superhydrophilic surface were 36.7 and 0 deg. The filling ratio of water was 50%, 65%, and 80%, respectively. Startup performance, thermal resistance, and liquid slug oscillation of OHPs were investigated experimentally at the heat input of 100–380 W. Experimental results showed that OHPs with the superhydrophilic nano-structured surface showed an enhanced heat transfer performance due to the nanostructure-induced capillary action for water in the horizontal direction. The optimum filling ratio was 65% in this work. Dryout was observed in the OHPs with the filling ratio of 50% at the heat input higher than 220 W. At the filling ratio of 80%, the working fluid was accumulated in the adiabatic and condensation section, and the driving force due to the water evaporation in evaporator was not high enough to activate the movements of liquid slugs. Heat transfer performance of OHP with nano-structured surface was higher than that of bare copper surface by introducing the additional capillary force.
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Klyce, Brig. "GTOs and HGT: genes are older than expected and can be installed by horizontal gene transfer, especially with help from viruses." In SPIE Optical Engineering + Applications, edited by Richard B. Hoover, Gilbert V. Levin, and Alexei Y. Rozanov. SPIE, 2012. http://dx.doi.org/10.1117/12.930131.

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Reports on the topic "Horizontal transfer of resistance genes"

1

Gaul, Stephen B., Isabel T. Harris, and D. L. Hank Harris. Molecular Characterization of Multidrug Resistant Salmonella Isolates From a Single Finisher Building for Determination of Horizontal Transmission of Resistance Genes. Ames (Iowa): Iowa State University, January 2005. http://dx.doi.org/10.31274/ans_air-180814-1094.

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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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