The Australian silver gull is an urban-adapted species that frequents anthropogenic waste sites. The enterobacterial flora of synanthropic birds often carries antibiotic resistance genes. Whole-genome sequence analyses of 425 Escherichia coli isolates from cloacal swabs of chicks inhabiting three coastal sites in New South Wales, Australia, cultured on media supplemented with meropenem, cefotaxime, or ciprofloxacin are reported. Phylogenetically, over 170 antibiotic-resistant lineages from 96 sequence types (STs) representing all major phylogroups were identified. Remarkably, 25 STs hosted the carbapenemase gene blaIMP-4, sourced only from Five Islands. Class 1 integrons carrying blaIMP and blaOXA alongside blaCTX-M and qnrS were notable. Multiple plasmid types mobilized blaIMP-4 and blaOXA-1, and 121 isolates (28%) carried either a ColV-like (18%) or a pUTI89-like (10%) F virulence plasmid. Phylogenetic comparisons to human isolates provided evidence of interspecies transmission. Our study underscores the importance of bystander species in the transmission of antibiotic-resistant and pathogenic E. coli. IMPORTANCE By compiling various genomic and phenotypic data sets, we have provided one of the most comprehensive genomic studies of Escherichia coli isolates from the Australian silver gull, on media containing clinically relevant antibiotics. The analysis of genetic structures capturing antimicrobial resistance genes across three gull breeding colonies in New South Wales, Australia, and comparisons to clinical data have revealed a range of trackable genetic signatures that highlight the broad distribution of clinical antimicrobial resistance in more than 170 different lineages of E. coli. Conserved truncation sizes of the class 1 integrase gene, a key component of multiple-drug resistance structures in the Enterobacteriaceae, represent unique deletion events that are helping to link seemingly disparate isolates and highlight epidemiologically relevant data between wildlife and clinical sources. Notably, only the most anthropogenically affected of the three sites (Five Islands) was observed to host carbapenem resistance, indicating a potential reservoir among the sites sampled.

• Keywords
• AMR, Escherichia coli, genomics, wildlife,
• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Drug Resistance, Microbial MeSH
• Anti-Infective Agents * MeSH
• Charadriiformes * microbiology   MeSH
• Animals, Wild MeSH
• Enterobacteriaceae MeSH
• Escherichia coli genetics   MeSH
• Phylogeny MeSH
• Humans MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Australia epidemiology   MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Anti-Infective Agents * MeSH

Escherichia coli ST216, including those that carry blaKPC-2, blaFOX-5, blaCTX-M-15 and mcr-1, have been linked to wild and urban-adapted birds and the colonisation of hospital environments causing recalcitrant, carbapenem-resistant human infections. Here we sequenced 22 multiple-drug resistant ST216 isolates from Australian silver gull chicks sampled from Five Islands, of which 21 carried nine or more antibiotic resistance genes including blaIMP-4 (n = 21), blaTEM-1b (n = 21), aac(3)-IId (n = 20), mph(A) (n = 20), catB3 (n = 20), sul1 (n = 20), aph(3")-Ib (n = 18) and aph(6)-Id (n = 18) on FIB(K) (n = 20), HI2-ST1 (n = 11) and HI2-ST3 (n = 10) plasmids. We show that (i) all HI2 plasmids harbour blaIMP-4 in resistance regions containing In809 flanked by IS26 (HI2-ST1) or IS15DI (HI2-ST3) and diverse metal resistance genes; (ii) HI2-ST1 plasmids are highly related to plasmids reported in diverse Enterobacteriaceae sourced from humans, companion animals and wildlife; (iii) HI2 were a feature of the Australian gull isolates and were not observed in international ST216 isolates. Phylogenetic analyses identified close relationships between ST216 from Australian gull and clinical isolates from overseas. E. coli ST216 from Australian gulls harbour HI2 plasmids encoding resistance to clinically important antibiotics and metals. Our studies underscore the importance of adopting a one health approach to AMR and pathogen surveillance.

• Keywords
• Australian silver gull, Chroicocephalus novaehollandiae, ST216, anthropogenic pollution, urban birds, whole genome sequencing, wildlife,
• Publication type
• Journal Article MeSH

Antimicrobial consumption in veterinary medicine has led to the spread of multi drug-resistance in clinically important bacteria, with the companion animals and their environment involved as emerging reservoirs. While CTX-M-15 and CMY-2 acquired β-lactamases have been widely detected in the bacterial population of companion and breeding animals in European area, DHA-1 enzymes have been rarely reported in veterinary medicine. The aim of the study was to characterize the Escherichia coli associated with mortality of a litter of Bulldog puppies in a breeding kennel located in Pesaro area, Central Italy. The E. coli strains O39 serotype were resistant to 3rd/4th generation cephalosporins, chloramphenicol, aminoglycosides, trimethoprim-sulfamethoxazole, and ciprofloxacin, retaining susceptibility to carbapenems, colistin, fosfomycin, and levofloxacin (by Microscan Autoscan4, EUCAST clinical breakpoints). Pulse field gel electrophoreses (PFGE-XbaI) on five E. coli strains revealed the presence of a single profile. Whole genome sequencing (WGS) analysis revealed a complex resistome, harboring bla TEM-1b, bla CTX-M-15, bla OXA-1, aph(6)-Ib, aac(6')Ib-cr, aac(3)-Ila, aph(6)-Id, aadA1, qnrB1, sul2, catA1, catB3, tetA, and dfrA14 genes located on a 302597 bp IncHI2/HI2A plasmid. Moreover, bla DHA-1, qnrB4, mph(A), sul1, and dfrA17 determinants were carried on an 83,429 bp IncFII plasmid. A bla CMY-2 determinant was carried on a 90,249 bp IncI1 plasmid. Two IncX1 and IncX4 plasmids without antimicrobial resistance genes were also detected. The presence of lpfA, iss, astA, and gad virulence factors was highlighted. This is the first report in Italy on an invasive infection in eight 2-weeks old dogs caused by the same MDR E. coli O39 bla CTX-M-15, bla CMY-2, bla DHA-1, and aac(6')-Ib-cr positive strain. The above MDR E. coli clone caused the death of the entire litter, despite amoxicillin-clavulanate and enrofloxacin administration. The tank for storage of the water used to prepare the milk-based meal for the litter was the suspected reservoir.

• Keywords
• CMY-2, CTX-M-15, DHA-1, E. coli, plasmids, whole genome sequencing,
• Publication type
• Journal Article MeSH

Wild animals foraging in the human-influenced environment are colonized by bacteria with clinically important antibiotic resistance. The occurrence of such bacteria in wildlife is influenced by various biological, ecological, and geographical factors which have not yet been fully understood. More research focusing on the human-animal-environmental interface and using novel approaches is required to understand the role of wild animals in the transmission of antibiotic resistance and to assess potential risks for the public health.

• Keywords
• antibiotics, carbapenemase, environment, landfill, transmission, wild animal,
• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacteria drug effects   enzymology   genetics   MeSH
• Drug Resistance, Bacterial MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• beta-Lactamases genetics   metabolism   MeSH
• Animals, Wild microbiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• beta-Lactamases MeSH
• carbapenemase MeSH Browser