Similarities in Virulence and Extended Spectrum Beta-Lactamase Gene Profiles among Cefotaxime-Resistant Escherichia coli Wastewater and Clinical Isolates

Abstract

The World Health Organization has identified antibiotic resistance as one of the largest threats to human health and food security. In this study, we compared antibiotic resistance patterns between ESBL-producing Escherichia coli from human clinical diseases and cefotaxime-resistant environmental strains, as well as their potential to be pathogenic. Antibiotic susceptibility was tested amongst clinical isolates (n = 11), hospital wastewater (n = 22), and urban wastewater (n = 36, both influent and treated effluents). Multi-drug resistance predominated (>70%) among hospitalwastewater and urban wastewater influent isolates. Interestingly, isolates from clinical and urban treated effluents showed similar multi-drug resistance rates (~50%). Most hospital wastewater isolates were Phylogroup A, while clinical isolates were predominately B2, with a more diverse phylogroup population in urban wastewater. ESBL characterization of cefotaxime-resistant populations identified blaCTX-M-1 subgroup as the most common, whereby blaKPC was more associated with ceftazidime and ertapenem resistance. Whole-genome sequencing of a carbapenemase-producing hospital wastewater E. coli strain revealed plasmid-mediated blaKPC-2. Among cefotaxime-resistant populations, over 60% of clinical and 30% of treated effluent E. coli encoded three or more virulence genes exhibiting a pathogenic potential. Together, the similarity among treated effluent E. coli populations and clinical strains suggest effluents could serve as a reservoir for future multi-drug resistant E. coli clinical infections.

Clinically Relevant β-Lactam Resistance Genes in Wastewater Treatment Plants

“…There are significantly fewer studies detecting bla OXA in the African region and they cover Algeria, where bla OXA-1 was detected [ 74 ]; Durban, South Africa, where cefotaxime-resistant E. coli were studied and bla OXA-1 was found as well [ 91 ]; Eastern Cape Province, South Africa, where bla OXA-1-like and bla OXA-48-like variants harbored by Enterobacterales isolated from effluents of WWTPs were noted [ 72 ]; and Tunisia, where C. freundii isolate carrying bla OXA-204 [ 121 ] and Enterobacterales strains possessing bla OXA-1 [ 127 ] were detected. American studies concerning WWTPs also confirm bla OXA presence in bacteria isolated from WWTP samples [ 80 , 90 , 102 , 104 , 119 , 125 , 133 ].…”

“…Liedhegner et al compared E. coli isolated from samples of various environmental compartments from one geographic area (clinical samples, hospital wastewater, and WWTP). The data including antibiotic resistance, virulence, and ESBL gene profiles confirmed high phenotypic and genotypic similarity across strains of these different origins and demonstrated potential health risks related to ESBL transmission [ 125 ]. An interesting study conducted by Raven et al showed genetic relatedness between E. coli isolated from 20 WWTPs in the UK, livestock farms, retail meat, and isolates responsible for human blood infections.…”

“…Environmental studies based on the analysis of bacterial strains during the treatment process most often concern the most critical pathogens posing the greatest threat, mainly Enterobacterales . In the reviewed literature, the predominantly tested and detected species among this bacteria family were Escherichia coli and K. pneumoniae [ 67 , 68 , 71 , 72 , 74 , 77 , 78 , 79 , 81 , 83 , 85 , 99 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ]; however, different species of Citrobacter spp., Enterobacter spp., Pseudomonas spp., Aeromonas spp., or others were noted as well [ 71 , 76 , 80 , 87 , 92 , 102 , 104 , 109 , 110 , 121 , 126 , 127 , 128 ].…”

“…It was also noted that these bacteria may survive the treatment process and that the WWTPs were unable to eradicate them completely. Generally, the number of MDR isolates decreased during the treatment, but for some, their proportion was still significant in effluents, in some even higher than in influent samples [ 70 , 71 , 73 , 86 , 88 , 92 , 94 , 97 , 99 , 118 , 119 , 123 , 125 , 129 , 130 ]. Moreover, analyzing downstream river or marine samples where final effluents are released, MDR isolates carrying ESBL enzymes were commonly detected [ 20 , 79 , 88 , 92 , 130 ].…”

The Impact of Chlorine Disinfection of Hospital Wastewater on Clonal Similarity and ESBL-Production in Selected Bacteria of the Family Enterobacteriaceae

“…(2019) [ 60 ] reported considerable variations in bla OXA concentrations in municipal wastewater. Amador et al (2015) [ 61 ] detected bla OXA in 27.8% of ESBL-E, and Liedhegner et al (2022) [ 62 ], in 86% of cefotaxime-resistant E. coli isolated from HWW. In the present study, bla OXA was the only gene whose abundance differed significantly between HWW samples collected from different sites.…”