Sequence Type 48 Escherichia coli Carrying the blaCTX-M-1 IncI1/ST3 Plasmid in Drinking Water in France.

Drinking water has rarely been recognized as a source of antimicrobial resistance for humans, and only in low-income countries. Here, a sequence type 48 Escherichia coli isolate carrying the blaCTX-M-1 IncI1/ST3 plasmid was recovered from drinking water in France. This plasmid was similar to other blaCTX-M-1 IncI1/ST3 plasmids found previously in animals and humans. Our findings highlight the possible human transfer of extended-spectrum ß-lactamase (ESBL) genes through drinking water in high-income countries.

High prevalence of international ESBL CTX-M-15-producing Enterobacter cloacae ST114 clone in animals.

OBJECTIVES: The objective of this study was to characterize ESBL-producing Enterobacter cloacae isolated from animals and to compare their clonal distribution with that of human-related isolates. METHODS: Among 635 clinical E. cloacae from horses, dogs and cats collected in France between 2010 and 2013, 36 were resistant to ceftiofur as determined by disc diffusion. ESBL genes were identified by sequencing. Plasmids carrying ESBL-encoding genes were characterized by PCR-based replicon typing, S1-PFGE and Southern blotting. IncHI2 plasmids were subtyped using the plasmid double-locus sequence typing scheme and multiplex amplification of the hipA, smr0092 and smr0183 genes. All E. cloacae were typed by PFGE and MLST. ST clustering was analysed by eBURST. RESULTS: All 36 ceftiofur-resistant E. cloacae produced an ESBL. Their PFGE patterns formed 23 clusters of high similarity and 13 STs and were isolated from epidemiologically unrelated animals (14 horses, 11 dogs and 11 cats) distributed throughout France. ST114, the most prevalent clone in humans, was over-represented in animals (16/36) compared with other human-related clones detected here. The blaCTX-M-15 gene was dominant (66.7%) and mostly carried on IncHI2 plasmids (ST1 subtype). ST114 isolates always produced CTX-M-15. CONCLUSIONS: Most ESBL-producing E. cloacae from animals studied here (69.4%) belonged to potentially high-risk clones in humans, in particular ST114 (44.4%). These data raise questions and potential concerns about the transfer of E. cloacae between animals and humans.

Population structure and antimicrobial susceptibility of Pseudomonas aeruginosa from animal infections in France.

BACKGROUND: Pseudomonas aeruginosa is a major human pathogen, which also affects animals. It is thought that P. aeruginosa has a non-clonal epidemic population structure, with distinct isolates found in humans, animals or the environment. However, very little is known about the structure of the P. aeruginosa population from diseased animals. Data on antimicrobial resistance are also scarce. RESULTS: Thirty-four already registered and 19 new MLST profiles were identified. Interestingly, a few clones were more prevalent, and clones associated to human outbreaks were also detected. Multidrug resistance phenotypes were overall rare. CONCLUSION: We highlight the non clonal structure of the population and show a higher prevalence of specific clones, possibly correlating with higher pathogenicity. The low proportion of antimicrobial resistance contrasts with the high resistance rate of human isolates.

Characterization of resistance genes in multidrug-resistant Salmonella enterica serotype Typhimurium isolated from diseased cattle in France (2002 to 2007).

We report here the results of the survey of antimicrobial resistance in 148 serotype Typhimurium strains isolated from cattle in France from 2002 to 2007 and displaying more than two antimicrobial resistances. Salmonella enterica serotype Typhimurium of definitive phage type 104 strains that are commonly resistant to ampicillin-amoxicillin, chloramphenicol-florfenicol, streptomycin-spectinomycin, sulfonamides, and tetracycline (ACSSuT phenotype) harbored resistance genes clustered on a complex class 1 integron In104 of the Salmonella genomic island 1 (SGI1). In our isolates, the most common antimicrobial resistance pattern was ACSSuT (77.7%) or ACSSuT combined to additional resistances. SGI1 was detected in 143 strains and constituted thus the main structure involved in resistance to antimicrobials in these strains. In spite of the high recombination potential of In104, SGI1 variability was quite limited among these strains since only two SGI1 variants, SGI1-B and SGI1-C, were identified. One hundred and thirty-eight out of the 143 SGI1-positive isolates belonged to the DT104 complex. Pulsed-field gel electrophoresis profile A was the most prevalent in 135 SGI1-positive isolates, confirming the diffusion of the DT104 clone. However, changes in phages susceptibility have occurred in three serotype Typhimurium strains of phage type DT12, as they displayed the same pulsed-field gel electrophoresis profile as the SGI1-positive serotype Typhimurium DT104. No variant harboring an additional resistance gene was identified, but the risk of recombination between SGI1 and any other mobile structure carrying other antimicrobial resistance genes is still an issue in serotype Typhimurium.