Wild birds, particularly silver gulls (Chroicocephalus novaehollandiae) that nest near anthropogenic sites, often harbour bacteria resistant to multiple antibiotics, including those considered of clinical importance. Here, we describe the whole genome sequence of Escherichia coli isolate CE1867 from a silver gull chick sampled in 2012 that hosted an I1 pST25 plasmid with blaSHV-12, a β-lactamase gene that encodes the ability to hydrolyze oxyimino β-lactams, and other antibiotic resistance genes. Isolate CE1867 is an ST297 isolate, a phylogroup B1 lineage, and clustered with a large ST297 O130:H11 clade, which carry Shiga toxin genes. The I1 plasmid belongs to plasmid sequence type 25 and is notable for its carriage of an atypical sul3-class 1 integron with mefB∆260, a structure most frequently reported in Australia from swine. This integron is a typical example of a Tn21-derived element that captured sul3 in place of the standard sul1 structure. Interestingly, the mercury resistance (mer) module of Tn21 is missing and has been replaced with Tn2-blaTEM-1 and a blaSHV-12 encoding module flanked by direct copies of IS26. Comparisons to similar plasmids, however, demonstrate a closely related family of ARG-carrying plasmids that all host variants of the sul3-associated integron with conserved Tn21 insertion points and a variable presence of both mer and mefB truncations, but predominantly mefB∆260.

• Klíčová slova
• AMR, Escherichia coli, IS26, Tn21, antibiotic, extended spectrum β-lactamase,
• Publikační typ
• časopisecké články MeSH

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.

• Klíčová slova
• AMR, Escherichia coli, genomics, wildlife,
• MeSH
• antibakteriální látky farmakologie   MeSH
• antibiotická rezistence MeSH
• antiinfekční látky * MeSH
• Charadriiformes * mikrobiologie   MeSH
• divoká zvířata MeSH
• Enterobacteriaceae MeSH
• Escherichia coli genetika   MeSH
• fylogeneze MeSH
• lidé MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Austrálie epidemiologie   MeSH
• Názvy látek
• antibakteriální látky MeSH
• antiinfekční látky * 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.

• Klíčová slova
• Australian silver gull, Chroicocephalus novaehollandiae, ST216, anthropogenic pollution, urban birds, whole genome sequencing, wildlife,
• Publikační typ
• časopisecké články MeSH

Silver gulls carry phylogenetically diverse Escherichia coli, including globally dominant extraintestinal pathogenic E. coli (ExPEC) sequence types and pandemic ExPEC-ST131 clades; however, our large-scale study (504 samples) on silver gulls nesting off the coast of New South Wales identified E. coli ST457 as the most prevalent. A phylogenetic analysis of whole-genome sequences (WGS) of 138 ST457 samples comprising 42 from gulls, 2 from humans (Australia), and 14 from poultry farmed in Paraguay were compared with 80 WGS deposited in public databases from diverse sources and countries. E. coli ST457 strains are phylogenetic group F, carry fimH145, and partition into five main clades in accordance to predominant flagella H-antigen carriage. Although we identified considerable phylogenetic diversity among the 138 ST457 strains, closely related subclades (<100 SNPs) suggested zoonotic or zooanthroponosis transmission between humans, wild birds, and food-producing animals. Australian human clinical and gull strains in two of the clades were closely related (≤80 SNPs). Regarding plasmid content, country, or country/source, specific connections were observed, including I1/ST23, I1/ST314, and I1/ST315 disseminating blaCMY-2 in Australia, I1/ST113 carrying blaCTX-M-8 and mcr-5 in Paraguayan poultry, and F2:A-:B1 plasmids of Dutch origin being detected across multiple ST457 clades. We identified a high prevalence of nearly identical I1/ST23 plasmids carrying blaCMY-2 among Australian gull and clinical human strains. In summary, ST457 is a broad host range, geographically diverse E. coli lineage that can cause human extraintestinal disease, including urinary tract infection, and displays a remarkable ability to capture mobile elements that carry and transmit genes encoding resistance to critically important antibiotics.

• Klíčová slova
• AmpC, ESBL, ExPEC, I1 plasmids, ST457,
• MeSH
• antibakteriální látky farmakologie   MeSH
• beta-laktamasy genetika   MeSH
• beta-laktamy MeSH
• divoká zvířata MeSH
• Escherichia coli * genetika   MeSH
• fylogeneze MeSH
• infekce vyvolané Escherichia coli * veterinární   MeSH
• lidé MeSH
• plazmidy genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Austrálie MeSH
• Názvy látek
• antibakteriální látky MeSH
• beta-laktamasy MeSH
• beta-laktamy MeSH