Jarocki, VM, Reid, CJ, Chapman, TA & Djordjevic, SP 2020, 'Escherichia coli ST302: Genomic Analysis of Virulence Potential and Antimicrobial Resistance Mediated by Mobile Genetic Elements', FRONTIERS IN MICROBIOLOGY, vol. 10.View/Download from: Publisher's site
Reid, CJ, Blau, K, Jechalke, S, Smalla, K & Djordjevic, SP 2020, 'Whole Genome Sequencing of Escherichia coli From Store-Bought Produce', FRONTIERS IN MICROBIOLOGY, vol. 10.View/Download from: Publisher's site
Zingali, T, Reid, CJ, Chapman, TA, Gaio, D, Liu, M, Darling, AE & Djordjevic, SP 2020, 'Whole genome sequencing analysis of porcine faecal commensal escherichia coli carrying class 1 integrons from sows and their offspring', Microorganisms, vol. 8, no. 6.View/Download from: Publisher's site
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Intensive pig production systems often rely on the use of antimicrobials and heavy metal feed additives to maintain animal health and welfare. To gain insight into the carriage of antimicrobial resistance genes (ARGs) in the faecal flora of commercially reared healthy swine, we characterised the genome sequences of 117 porcine commensal E. coli that carried the class 1 integrase gene (intI1+). Isolates were sourced from 42 healthy sows and 126 of their offspring from a commercial breeding operation in Australia in 2017. intI1+ E. coli was detected in 28/42 (67%) sows and 90/126 (71%) piglets. Phylogroup A, particularly clonal complex 10, and phylogroup B1 featured prominently in the study collection. ST10, ST20, ST48 and ST361 were the dominant sequence types. Notably, 113/117 isolates (96%) carried three or more ARGs. Genes encoding resistance to lactams, aminoglycosides, trimethoprim, sulphonamides, tetracyclines and heavy metals were dominant. ARGs encoding resistance to last-line agents, such as carbapenems and third generation cephalosporins, were not detected. IS26, an insertion sequence noted for its ability to capture and mobilise ARGs, was present in 108/117 (92%) intI1+ isolates, and it played a role in determining class 1 integron structure. Our data shows that healthy Australian pig faeces are an important reservoir of multidrug resistant E. coli that carry genes encoding resistance to multiple first-generation antibiotics and virulence-associated genes.
Cummins, ML, Reid, CJ, Roy Chowdhury, P, Bushell, RN, Esbert, N, Tivendale, KA, Noormohammadi, AH, Islam, S, Marenda, MS, Browning, GF, Markham, PF & Djordjevic, SP 2019, 'Whole genome sequence analysis of Australian avian pathogenic Escherichia coli that carry the class 1 integrase gene.', Microbial genomics, vol. 5, no. 2.View/Download from: Publisher's site
Avian pathogenic Escherichia coli (APEC) cause widespread economic losses in poultry production and are potential zoonotic pathogens. Genome sequences of 95 APEC from commercial poultry operations in four Australian states that carried the class 1 integrase gene intI1, a proxy for multiple drug resistance (MDR), were characterized. Sequence types ST117 (22/95), ST350 (10/95), ST429 and ST57 (each 9/95), ST95 (8/95) and ST973 (7/95) dominated, while 24 STs were represented by one or two strains. FII and FIB repA genes were the predominant (each 93/95, 98 %) plasmid incompatibility groups identified, but those of B/O/K/Z (25/95, 26 %) and I1 (24/95, 25 %) were also identified frequently. Virulence-associated genes (VAGs) carried by ColV and ColBM virulence plasmids, including those encoding protectins [iss (91/95, 96 %), ompT (91/95, 96 %) and traT (90/95, 95 %)], iron-acquisition systems [sitA (88/95, 93 %), etsA (87/95, 92 %), iroN (84/95, 89 %) and iucD/iutA (84/95, 89 %)] and the putative avian haemolysin hylF (91/95, 96 %), featured prominently. Notably, mobile resistance genes conferring resistance to fluoroquinolones, colistin, extended-spectrum β-lactams and carbapenems were not detected in the genomes of these 95 APEC but carriage of the sulphonamide resistance gene, sul1 (59/95, 63 %), the trimethoprim resistance gene cassettes dfrA5 (48/95, 50 %) and dfrA1 (25/95, 27 %), the tetracycline resistance determinant tet(A) (51/95, 55 %) and the ampicillin resistance genes blaTEM-1A/B/C (48/95, 52 %) was common. IS26 (77/95, 81 %), an insertion element known to capture and mobilize a wide spectrum of antimicrobial resistance genes, was also frequently identified. These studies provide a baseline snapshot of drug-resistant APEC in Australia and their role in the carriage of ColV-like virulence plasmids.
Reid, C, McKinnon, J & Djordjevic, S 2019, 'Clonal ST131-H22 Escherichia coli strains from a healthy pig and a human urinary tract infection carry highly similar resistance and virulence plasmids', Microbial Genomics, vol. 5, no. 9.
The interplay between food production animals, humans and the environment with respect to the transmission of drugresistant pathogens is widely debated and poorly understood. Pandemic uropathogenic Escherichia coli ST131-H30Rx, with
conserved fluoroquinolone and cephalosporin resistance, are not frequently identified in animals. However, the phylogenetic
precursor lineage ST131-H22 in animals and associated meat products is being reported with increasing frequency. Here we
characterized two highly related ST131-H22 strains, one from a healthy pig and the other from a human infection (in 2007 and
2009, respectively). We used both long and short genome sequencing and compared them to ST131-H22 genome sequences
available in public repositories. Even within the context of H22 strains, the two strains in question were highly related, separated
by only 20 core SNPs. Furthermore, they were closely related to a faecal strain isolated in 2010 from a geographically distinct,
healthy human in New South Wales, Australia. The porcine and hospital strains carried highly similar HI2-ST3 multidrug resistant plasmids with differences in the hospital strain arising due to IS-mediated insertions and rearrangements. Near identical
ColV plasmids were also present in both strains, further supporting their shared evolutionary history. This work highlights the
importance of adopting a One Health approach to genomic surveillance to gain insights into pathogen evolution and spread.
Reid, CJ, DeMaere, MZ & Djordjevic, SP 2019, 'Australian porcine clonal complex 10 (CC10) Escherichia coli belong to multiple sublineages of a highly diverse global CC10 phylogeny', Microbial Genomics, vol. 5, pp. ---.View/Download from: Publisher's site
Wyrsch, ER, Reid, CJ, DeMaere, MZ, Liu, MY, Chapman, TA, Roy Chowdhury, P & Djordjevic, SP 2019, 'Complete Sequences of Multiple-Drug Resistant IncHI2 ST3 Plasmids in Escherichia coli of Porcine Origin in Australia', Frontiers in Sustainable Food Systems, vol. 3.View/Download from: Publisher's site
Reid, C, Wyrsch, E, Chowdhury, PR, Zingali, T, Liu, M, Darling, A, Chapman, T & Djordjevic, S 2017, 'Porcine commensal Escherichia coli: A reservoir for class 1 integrons associated with IS26'.View/Download from: Publisher's site
Abstract Porcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial resistance and virulence-associated genes (VAGs) and the zoonotic potential of commensal Escherichia coli from swine is largely unknown. Furthermore, little is known about the role of commensal E. coli as contributors to the mobilisation of antimicrobial resistance genes between food animals and the environment. Here, we report whole genome sequence analysis of 141 E. coli from the faeces of healthy pigs. Most strains belonged to phylogroups A and B1 and carried i) a class 1 integron; ii) VAGs linked with extraintestinal infection in humans; iii) antimicrobial resistance genes bla TEM , aphAl, cmlA, strAB, tet(A) A, dfrA12, dfrA5, sul1, sul2, sul3 ; iv) IS26; and v) heavy metal resistance genes ( merA, cusA, terA ). Carriage of the sulphonamide resistance gene sul3 was notable in this study. The 141 strains belonged to 42 multilocus sequence types, but clonal complex 10 featured prominently. Structurally diverse class 1 integrons that were frequently associated with IS26 carried unique genetic features that were also identified in extraintestinal pathogenic E. coli (ExPEC) from humans. This study provides the first detailed genomic analysis and point of reference for commensal E. coli of porcine origin, facilitating tracking of specific lineages and the mobile resistance genes they carry. Conflict of Interest Statement None to declare.
Reid, CJ, Wyrsch, ER, Roy Chowdhury, P, Zingali, T, Liu, M, Darling, AE, Chapman, TA & Djordjevic, SP 2017, 'Porcine commensal Escherichia coli: a reservoir for class 1 integrons associated with IS26.', Microbial Genomics, vol. 3, no. 12, pp. 1-13.View/Download from: Publisher's site
Porcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial-resistance genes (ARGs) and virulence-associated genes (VAGs), and the zoonotic potential of commensal Escherichia coli from swine are largely unknown. Furthermore, little is known about the role of commensal E. coli as contributors to the mobilization of ARGs between food animals and the environment. Here, we report whole-genome sequence analysis of 103 class 1 integron-positive E. coli from the faeces of healthy pigs from two commercial production facilities in New South Wales, Australia. Most strains belonged to phylogroups A and B1, and carried VAGs linked with extraintestinal infection in humans. The 103 strains belonged to 37 multilocus sequence types and clonal complex 10 featured prominently. Seventeen ARGs were detected and 97 % (100/103) of strains carried three or more ARGs. Heavy-metal-resistance genes merA, cusA and terA were also common. IS26 was observed in 98 % (101/103) of strains and was often physically associated with structurally diverse class 1 integrons that carried unique genetic features, which may be tracked. This study provides, to our knowledge, the first detailed genomic analysis and point of reference for commensal E. coli of porcine origin in Australia, facilitating tracking of specific lineages and the mobile resistance genes they carry.
Reid, CJ, Roy Chowdhury, P & Djordjevic, SP 2015, 'Tn6026 and Tn6029 are found in complex resistance regions mobilised by diverse plasmids and chromosomal islands in multiple antibiotic resistant Enterobacteriaceae.', Plasmid, vol. 80, pp. 127-137.View/Download from: Publisher's site
Transposons flanked by direct copies of IS26 are important contributors to the evolution of multiple antibiotic resistance. Tn6029 and Tn6026 are examples of composite transposons that have become widely disseminated on small and large plasmids with different incompatibility markers in pathogenic and commensal Escherichia coli and various serovars of Salmonella enterica. Some of the plasmids that harbour these transposons also carry combinations of virulence genes. Recently, Tn6029 and Tn6026 and derivatives thereof have been found on chromosomal islands in both established and recently emerged pathogens. While Tn6029 and Tn6026 carry genes encoding resistance to older generation antibiotics, they also provide a scaffold for the introduction of genes encoding resistance to a wide variety of clinically relevant antibiotics that are mobilised by IS26. As a consequence, Tn6029 and Tn6026 or variants are likely to increasingly feature in complex resistance regions in multiple antibiotic resistant Enterobacteriaceae that threaten the health of humans and food production animals.