Unraveling virulence determinants in extended-spectrum beta-lactamase-producing Escherichia coli from East Africa using whole-genome sequencing.

Escherichia coli significantly causes nosocomial infections and rampant spread of antimicrobial resistance (AMR). There is limited data on genomic characterization of extended-spectrum ß-lactamase (ESBL)-producing E. coli from African clinical settings. This hospital-based longitudinal study unraveled the genetic resistance elements in ESBL E. coli isolates from Uganda and Tanzania using whole-genome sequencing (WGS). A total of 142 ESBL multi-drug resistant E. coli bacterial isolates from both Tanzania and Uganda were sequenced and out of these, 36/57 (63.1%) and 67/85 (78.8%) originated from Uganda and Tanzania respectively. Mutations in RarD, yaaA and ybgl conferring resistances to chloramphenicol, peroxidase and quinolones were observed from Ugandan and Tanzanian isolates. We reported very high frequencies for blaCTX-M-15 with 11/18(61.1%), and blaCTX-M-27 with 12/23 (52.1%), blaTEM-1B with 13/23 (56.5%) of isolates originating from Uganda and Tanzania respectively all conferring resistance to Beta-lactam-penicillin inhibitors. We observed chloramphenicol resistance-conferring gene mdfA in 21/23 (91.3%) of Tanzanian isolates. Extraintestinal E. coli sequence type (ST) 131 accounted for 5/59 (8.4%) of Tanzanian isolates while enterotoxigenic E. coli ST656 was reported in 9/34 (26.4%) of Ugandan isolates. Virulence factors originating from Shigella dysenteriae Sd197 (gspC, gspD, gspE, gspF, gspG, gspF, gspH, gspI), Yersinia pestis CO92 (irp1, ybtU, ybtX, iucA), Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 (csgF and csgG), and Pseudomonas aeruginosa PAO1 (flhA, fliG, fliM) were identified in these isolates. Overall, this study highlights a concerning prevalence and diversity of AMR-conferring elements shaping the genomic structure of multi-drug resistant E. coli in clinical settings in East Africa. It underscores the urgent need to strengthen infection-prevention controls and advocate for the routine use of WGS in national AMR surveillance and monitoring programs.Availability of WGS analysis pipeline: the rMAP source codes, installation, and implementation manual can free be accessed via https://github.com/GunzIvan28/rMAP .

Gastrointestinal Tract Colonization Rate of Extended-Spectrum Beta-Lactamase-Producing Gram-Negative Bacteria and Associated Factors Among Orthopaedic Patients in a Tertiary Hospital in Tanzania: Implications for Infection Prevention.

BACKGROUND: The dual burden of road traffic accidents and antimicrobial resistance in orthopaedic infections is challenging already strained health-care systems. Limited information exists in Tanzania on antimicrobial resistance surveillance to delineate the potential sources of multi-drug-resistant bacteria for specific mitigation strategies among orthopaedic patients. METHODS: A longitudinal study was conducted at Bugando Medical Centre in Mwanza city between January and May 2020. It involved the collection of rectal swabs/stools, hand swabs, and environmental sampling to identify extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria. Participants' data were collected using a structured questionnaire and analysed to determine factors associated with ESBL colonization among index orthopaedic patients and correlates with other ESBL sources using OR (95% CI) and a cut-off p-value of ≤0.05. RESULTS: We found that 47.2% (125/265) of index patients, 77.8% (14/18) of neighbouring patients, 8.3% (2/24) of health-care workers, 72.2% (13/18) of non-medical caregivers, and 31.4% (27/86) of samples taken from the hospital environment had ESBL producers. Escherichia coli and Klebsiella spp. predominated among participants and Acinetobacter spp. predominated in the environmental samples. Patients with open fractures had increased odds of being colonized with ESBL producers [OR (95% CI): 2.08 (1.16-3.75); p=0.015]. The floor below patients' beds was commonly contaminated; however, the odds of environmental contamination decreased on the third round of sampling [OR (95% CI: 0.16 (0.04-0.67); p=0.012], apparently as a result of parallel infection prevention and control responsive measures against coronavirus disease 2019 (COVID-19). CONCLUSION: We found a high occurrence of ESBL colonization among participants and in the environmentat this tertiary hospital. The importance of routine ESBL surveillance among orthopaedic patients with open fractures on admission and strengthened decontamination of health-care premises is reiterated.