Meticillin-resistant staphylococcus aureus (MRSA) among animals in France : prevalence and co-resistance

Meticillin-Resistant Staphylococcus aureus (MRSA) is an important human pathogen. Recent infections in humans in the Netherlands (2006) were attributed to ST398 MRSA isolates from pigs and highlighted the potential risk for humans to get infected with MRSA strains of animal origin. Most data available at this time argue for a large prevalence, albeit variable among countries, of ST398 MRSA colonizing (but not infecting) pigs. With respect to transmission to humans, professional exposure to pigs remains the main risk factor identified so far. In Europe, data on MRSA (and mainly non-ST398 MRSA) in other animal species than pigs are still scarce. Therefore, further studies are needed for a more acute evaluation of the risk of spreading to humans.Le staphylocoque doré (Staphylococcus aureus) résistant à la méticilline (SARM) constitue un pathogène majeur en médecine humaine. Des cas récents d’infections liées à des souches d’origine porcine (clone ST398) aux Pays-Bas en 2006 ont mis en lumière le risque que pouvait constituer le SARM animal pour l’homme. Les principales données disponibles restent encore issues à ce jour de la filière porcine, et montrent une large prévalence, bien que variable d’un pays à l’autre, d’un clone colonisateur peu virulent, et principalement du groupe clonal ST398. Les infections humaines apparaissent, quant à elles, limitées aux expositions professionnelles (éleveurs de porcs). Dans les autres espèces animales, le SARM (surtout non-ST398) reste peu décrit, en France comme en Europe. Il conviendra, au cours des prochaines années, de compléter ces données pour préciser les évolutions éventuelles du pouvoir pathogène pour l’homme des SARM animaux

Resistance to carbapenems in animals in the absence of use

Les carbapénèmes, classe d’antibiotiques naturels ou semi-synthétiques de la famille des bêta-lactamines sont des antibiotiques de première importance en médecine humaine. Même si l’usage des carbapénèmes est interdit en médecine vétérinaire (antibiotiques critiques), des souches bactériennes résistantes à cette classe d’antibiotiques sont décrites dans le secteur animal. À partir d’exemple récents, cette communication a pour objectif de faire un point sur la situation chez l’animal domestique en France. En particulier, l’exemple de Pseudomonas aeruginosa dans des infections cutanées chez le chien illustre comment la résistance aux carbapénèmes est très probablement sélectionnée par l’usage des fluoroquinolones et/ou des aminosides (mécanismes d’efflux). Au final, ces éléments constituent une occasion supplémentaire de rappeler à la profession vétérinaire, l’importance de l’usage raisonné des antibiotiques en toutes circonstances.Carbapenems, a class among beta-lactams are antibiotics of crucial importance in human medicine. Even though carbapenems are not authorized in veterinary medicine, various bacteria harbouring resistance to carbapenems have been reported in the animal sector. Here, based on recent examples, we provide an update on the epidemiological situation of carbapenem resistance in domestic animals in France. Notably, the case of Pseudomonas aeruginosa in the context of external otitis in dogs highlights to what extent resistance to carbapenems may have likely been selected by the use of fluoroquinolones and/or aminoglycosides. At the end, these data stress again the importance of a rational use of antibiotics at any time in veterinary medicine

M-protein and other intrinsic virulence factors of Streptococcus pyogenes are encoded on an ancient pathogenicity island

BACKGROUND: The increasing number of completely sequenced bacterial genomes allows comparing their architecture and genetic makeup. Such new information highlights the crucial role of lateral genetic exchanges in bacterial evolution and speciation. RESULTS: Here we analyzed the twelve sequenced genomes of Streptococcus pyogenes by a naïve approach that examines the preferential nucleotide usage along the chromosome, namely the usage of G versus C (GC-skew) and T versus A (TA-skew). The cumulative GC-skew plot presented an inverted V-shape composed of two symmetrical linear segments, where the minimum and maximum corresponded to the origin and terminus of DNA replication. In contrast, the cumulative TA-skew presented a V-shape, which segments were interrupted by several steep slopes regions (SSRs), indicative of a different nucleotide composition bias. Each S. pyogenes genome contained up to nine individual SSRs, encompassing all described strain-specific prophages. In addition, each genome contained a similar unique non-phage SSR, the core of which consisted of 31 highly homologous genes. This core includes the M-protein, other mga-related factors and other virulence genes, totaling ten intrinsic virulence genes. In addition to a high content in virulence-related genes and to a peculiar nucleotide bias, this SSR, which is 47 kb-long in a M1GAS strain, harbors direct repeats and a tRNA gene, suggesting a mobile element. Moreover, its complete absence in a M-protein negative group A Streptococcus natural isolate demonstrates that it could be spontaneously lost, but in vitro deletion experiments indicates that its excision occurred at very low rate. The stability of this SSR, combined to its presence in all sequenced S. pyogenes sequenced genome, suggests that it results from an ancient acquisition. CONCLUSION: Thus, this non-phagic SSR is compatible with a pathogenicity island, acquired before S. pyogenes speciation. Its potential excision might bear relevance for vaccine development, because vaccines targeting M-protein might select for M-protein-negative variants that still carry other virulence determinants

vanA in Enterococcus faecium, Enterococcus faecalis, and Enterococcus casseliflavus detected in French cattle.

The goal of this study was to assess the presence of enterococci species presenting van-mediated glycopeptide resistance in French cattle. Fecal samples were collected from healthy and sick animals, and enterococci were screened for vancomycin resistance. Vancomycin resistance was principally encountered in Enterococcus gallinarum and Enterococcus casseliflavus strains. However, glycopeptide resistance was detected in three different species of enterococci (E. faecalis, E. faecium, and E. casseliflavus). Molecular characterization of the genetic support proved that they all presented the prototypic VanA element. Interestingly, the E. casseliflavus strain displayed a remarkable VanB phenotype/vanA-vanC genotype. Transferability, associated resistances, and factors of vanA cotransfer were sought. This study proved that acquired vanA genes can still be detected in food-producing animals more than a decade after the avoparcin ban. Indeed, calves, which are recurrently exposed to antibiotics in France, may allow the re-emergence of glycopeptide resistance through coselection factors, and this might potentially be concerning for human health

Global transmission of extended-spectrum cephalosporin resistance in Escherichia coli driven by epidemic plasmids

Background Extended-spectrum cephalosporins (ESCs) are third and fourth generation cephalosporin antimicrobials used in humans and animals to treat infections due to multidrug-resistant (MDR) bacteria. Resistance to ESCs (ESC-R) in Enterobacterales is predominantly due to the production of extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (AmpCs). The dynamics of ESBLs and AmpCs are changing across countries and host species, the result of global transmission of ESC-R genes. Plasmids are known to play a key role in this dissemination, but the relative importance of different types of plasmids is not fully understood. Methods In this study, Escherichia coli with the major ESC-R genes blaCTX-M-1, blaCTX-M-15, blaCTX-M-14 (ESBLs) and blaCMY-2 (AmpC), were selected from diverse host species and other sources across Canada, France and Germany, collected between 2003 and 2017. To examine in detail the vehicles of transmission of the ESC-R genes, long- and short-read sequences were generated to obtain complete contiguous chromosome and plasmid sequences (n = 192 ESC-R E. coli). The types, gene composition and genetic relatedness of these plasmids were investigated, along with association with isolate year, source and geographical origin, and put in context with publicly available plasmid sequences. Findings We identified five epidemic resistance plasmid subtypes with distinct genetic properties that are associated with the global dissemination of ESC-R genes across multiple E. coli lineages and host species. The IncI1 pST3 blaCTX-M-1 plasmid subtype was found in more diverse sources than the other main plasmid subtypes, whereas IncI1 pST12 blaCMY-2 was more frequent in Canadian and German human and chicken isolates. Clonal expansion also contributed to the dissemination of the IncI1 pST12 blaCMY-2 plasmid in ST131 and ST117 E. coli harbouring this plasmid. The IncI1 pST2 blaCMY-2 subtype was predominant in isolates from humans in France, while the IncF F31:A4:B1 blaCTX-M-15 and F2:A-:B- blaCTX-M-14 plasmid subtypes were frequent in human and cattle isolates across multiple countries. Beyond their epidemic nature with respect to ESC-R genes, in our collection almost all IncI1 pST3 blaCTX-M-1 and IncF F31:A4:B1 blaCTX-M-15 epidemic plasmids also carried multiple antimicrobial resistance (AMR) genes conferring resistance to other antimicrobial classes. Finally, we found genetic signatures in the regions surrounding specific ESC-R genes, identifying the predominant mechanisms of ESC-R gene movement, and using publicly available databases, we identified these epidemic plasmids from widespread bacterial species, host species, countries and continents. Interpretation We provide evidence that epidemic resistance plasmid subtypes contribute to the global dissemination of ESC-R genes, and in addition, some of these epidemic plasmids confer resistance to multiple other antimicrobial classes. The success of these plasmids suggests that they may have a fitness advantage over other plasmid types and subtypes. Identification and understanding of the vehicles of AMR transmission are crucial to develop and target strategies and interventions to reduce the spread of AMR