Genomic analysis of Citrobacter from Australian wastewater and silver gulls reveals novel sequence types carrying critically important antibiotic resistance genes

dc.contributor.authorHem, S.
dc.contributor.authorCummins, M.L.
dc.contributor.authorWyrsch, E.R.
dc.contributor.authorDrigo, B.
dc.contributor.authorHoye, B.J.
dc.contributor.authorMaute, K.
dc.contributor.authorSanderson Smith, M.
dc.contributor.authorGorman, J.
dc.contributor.authorBogema, D.R.
dc.contributor.authorJenkins, C.
dc.contributor.authorDeutscher, A.T.
dc.contributor.authorYam, J.
dc.contributor.authorHai, F.
dc.contributor.authorDonner, E.
dc.contributor.authorJarocki, V.M.
dc.contributor.authorDjordjevic, S.P.
dc.date.issued2024
dc.description.abstractAntimicrobial resistance (AMR) is a major public health concern, and environmental bacteria have been recognized as important reservoirs of antimicrobial resistance genes (ARGs). Citrobacter, a common environmental bacterium and opportunistic pathogen in humans and other animals, has been largely understudied in terms of its diversity and AMR potential. Whole-genome (short-read) sequencing on a total of 77 Citrobacter isolates obtained from Australian silver gull (Chroicocephalus novaehollandiae) (n = 17) and influent wastewater samples (n = 60) was performed, revealing a diverse Citrobacter population, with seven different species and 33 sequence types, 17 of which were novel. From silver gull using non-selective media we isolated a broader range of species with little to no mobilised ARG carriage. Wastewater isolates (selected using Carbapenem- Resistant Enterobacterales (CRE) selective media) carried a heavy burden of ARGs (up to 21 ARGs, conferring resistance to nine classes of antibiotics), with several novel multidrug-resistant (MDR) lineages identified, including C. braakii ST1110, which carried ARGs conferring resistance to eight to nine classes of antibiotics, and C. freundii ST1105, which carried two carbapenemase genes, blaIMP-4 in class 1 integron structure, and blaKPC-2. Additionally, we identified an MDR C. portucalensis isolate carrying blaNDM-1, blaSHV-12, and mcr-9. We identified IncC, IncM2, and IncP6 plasmids as the likely vectors for many of the critically important mobilised ARGs. Phylogenetic analyses were performed to assess any epidemiological linkages between isolation sources, demonstrating low relatedness across sources beyond the ST level. However, these analyses did reveal some closer relationships between strains from disparate wastewater sources despite their collection some 13,000 km apart. These findings support the need for future surveillance of Citrobacter populations in wastewater and wildlife populations to monitor for potential opportunistic human pathogens.
dc.identifier.citationScience of the Total Environment, 2024; 909(168608):1-15
dc.identifier.doi10.1016/j.scitotenv.2023.168608
dc.identifier.issn0048-9697
dc.identifier.issn1879-1026
dc.identifier.urihttps://hdl.handle.net/11541.2/37047
dc.language.isoen
dc.publisherElsevier
dc.rightsCopyright 2023 Elsevier
dc.source.urihttps://doi.org/10.1016/j.scitotenv.2023.168608
dc.subjectantimicrobial resistance
dc.subjectcarbapenamases
dc.subjectCitrobacter
dc.subjectgulls
dc.subjectplasmids
dc.subjectwastewater
dc.titleGenomic analysis of Citrobacter from Australian wastewater and silver gulls reveals novel sequence types carrying critically important antibiotic resistance genes
dc.typeJournal article
pubs.publication-statusPublished
ror.mmsid9916812531001831

Files

Collections