Extraintestinal pathogenic Escherichia coli (ExPEC) sequence type (ST) 38 is one of the top 10 human pandemic lineages. Although a major cause of urinary tract and blood stream infections, ST38 has been poorly characterized from a global phylogenomic perspective. A comprehensive genome-scale analysis of 925 ST38 isolate genomes identified two broad ancestral clades and linkage of discrete ST38 clusters with specific bla CTX-M variants. In addition, the clades and clusters carry important virulence genes, with diverse but poorly characterized plasmids. Numerous putative interhost and environment transmission events were identified here by the presence of ST38 clones (defined as isolates with ≤35 SNPs) within humans, companion animals, food sources, urban birds, wildlife, and the environment. A small cluster of international ST38 clones from diverse sources, likely representing progenitors of a hospital outbreak that occurred in Brisbane, Australia, in 2017, was also identified. Our study emphasizes the importance of characterizing isolate genomes derived from nonhuman sources and geographical locations, without any selection bias.

• Klíčová slova
• EAEC, One Health, ST38, bla CTX-M, drug resistance, enteroaggregative E. coli, genomic surveillance, phylogenomics, β-lactamase genes,
• MeSH
• Escherichia coli genetika   MeSH
• extraintestinální patogenní Escherichia coli * MeSH
• fylogeneze MeSH
• infekce vyvolané Escherichia coli * epidemiologie   MeSH
• lidé MeSH
• plazmidy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Escherichia coli sequence type 963 (ST963) is a neglected lineage closely related to ST38, a globally widespread extraintestinal pathogenic ST causing urinary tract infections (UTI) as well as sepsis in humans. Our current study aimed to improve the knowledge of this understudied ST by carrying out a comprehensive comparative analysis of whole-genome sequencing data consisting of 31 isolates from silver gulls in Australia along with another 80 genomes from public resources originating from geographically scattered regions. ST963 was notable for carriage of cephalosporinase gene blaCMY-2, which was identified in 99 isolates and was generally chromosomally encoded. ST963 isolates showed otherwise low carriage of antibiotic resistance genes, in contrast with the closely related E. coli ST38. We found considerable phylogenetic variability among international ST963 isolates (up to 11,273 single nucleotide polymorphisms [SNPs]), forming three separate clades. A major clade that often differed by 20 SNPs or less consisted of Australian isolates of both human and animal origin, providing evidence of zoonotic or zooanthropogenic transmission. There was a high prevalence of virulence F29:A-:B10 pUTI89-like plasmids within E. coli ST963 (n = 88), carried especially by less variable isolates exhibiting ≤1,154 SNPs. We characterized a novel 115,443-bp pUTI89-like plasmid, pCE2050_A, that carried a traS:IS5 insertion absent from pUTI89. Since IS5 was also present in a transposition unit bearing blaCMY-2 on chromosomes of ST963 strains, IS5 insertion into pUTI89 may enable mobilization of the blaCMY-2 gene from the chromosome/transposition unit to pUTI89 via homologous recombination. IMPORTANCE We have provided the first comprehensive genomic study of E. coli ST963 by analyzing various genomic and phenotypic data sets of isolates from Australian silver gulls and comparison with genomes from geographically dispersed regions of human and animal origin. Our study suggests the emergence of a specific blaCMY-2-carrying E. coli ST963 clone in Australia that is widely spread across the continent by humans and birds. Genomic analysis has revealed that ST963 is a globally dispersed lineage with a remarkable set of virulence genes and virulence plasmids described in uropathogenic E. coli. While ST963 separated into three clusters, a unique specific clade of Australian ST963 isolates harboring a chromosomal copy of AmpC β-lactamase encoding the gene blaCMY-2 and originating from both humans and wild birds was identified. This phylogenetically close cluster comprised isolates of both animal and human origin, thus providing evidence of interspecies zoonotic transmission. The analysis of the genetic environment of the AmpC β-lactamase-encoding gene highlighted ongoing evolutionary events that shape the carriage of this gene in ST963.

• Klíčová slova
• Australia, Escherichia coli, ST963, WGS, comparative genomics, humans, phylogenetic analysis, silver gulls, transmission, β-lactamases,
• MeSH
• Charadriiformes * mikrobiologie   MeSH
• Escherichia coli * genetika   MeSH
• fylogeneze MeSH
• infekce vyvolané Escherichia coli * přenos   veterinární   MeSH
• lidé MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Austrálie MeSH

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

Poultry represents a common source of bacteria with resistance to antibiotics including the critically important ones. Selective cultivation using colistin, cefotaxime and meropenem was performed for 66 chicken samples coming from 12 farms in Paraguay while two breeding companies supplied the farms. A total of 62 Escherichia coli and 22 Klebsiella pneumoniae isolates were obtained and representative isolates were subjected to whole-genome sequencing. Relatively high prevalence of phylogenetic group D and F was observed in E. coli isolates and several zoonotic sequence types (STs) including ST457 (14 isolates), ST38 (5), ST10 (2), ST117 (2) or ST93 (4) were detected. Isolates from three farms, which purchased chicken from a Paraguayan hatchery showed higher prevalence of mcr-5.1 and blaCTX-M-8 compared to the other nine farms, which purchased chickens from a Brazilian hatchery. Moreover, none of the K. pneumoniae isolates were linked to the Paraguayan hatchery. ESBL/AmpC and mcr-5-carrying multi-drug resistant (MDR) plasmids were characterized, and complete sequences were obtained for eight plasmids. The study shed light on Paraguayan poultry farms as a reservoir of antibiotic resistance commonly conferred via MDR plasmids and showed linkage between resistance and origin of the chickens at the hatcheries level.

• Klíčová slova
• E. coli, ESBL/AmpC, I1 plasmids, K. pneumoniae, colistin,
• Publikační typ
• časopisecké články 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