Escherichia coli as Possible Agents of Spread of Multidrug Resistance in Port Harcourt, Rivers State.

Abstract

Multidrug resistance (MDR) continues to be a growing global issue. The problem of MDR is fuelled in part by the spread of the genes encoding resistance horizontally which is linked particularly to conjugation involving plasmids. Studies have demonstrated the presence of plasmids in drug resistant isolates, few have shown a link between these plasmids and drug resistance via plasmid curing especially in our locale. This study set out to explore this link in Escherichia coli isolates from Port Harcourt, Nigeria. Plasmid curing was done on a selection of clinical and non-clinical bacteria using acridine orange and antibiotic susceptibility testing carried out on both cured and uncured variants. Data generated was analysed to ascertain the multiple antibiotic resistance (MAR) index and MDR of each isolate. Data was then compared to ascertain effects of plasmid curing on antibiotic resistance of the isolates. Results revealed a decrease in resistance to 7 of 8 antibiotics following plasmid curing. The highest change was noted in ceftazidime (40%), followed by ofloxacin (26.7%). Plasmid curing caused a shift in MAR index values of isolates from higher to lower indices. At MAR index values of ≤0.25 occurrence increased from 5% to 36.7% while at MAR index values ≥0.75, occurrence reduced from 29.9% to 10.0%. A reduction in the degree of MDR was noted (from 55% to 36.7%). Strikingly, the reduction in MDR level of non-clinical isolates was 30% as opposed to 3.4% in the clinical isolates. This study shows a link between plasmids and antibiotic resistance. For the non-clinical isolates, the high-level link between MDR and plasmid carriage could indicate a higher use of antimicrobials in non-clinical rather than clinical settings. Additionally, it could be an indicator for a higher risk of the transfer of MDR determinants from non-clinical sources to human populations in our locale.

Antibiotic resistance and ESBL production in Escherichia coli from various sources in Aba metropolis, Nigeria

“…Similar moderate rates in non-clinical E. coli isolates have been described by other studies (Haberecht et al 2019 ; Sabala et al 2021 ; Adelowo et al 2014 ; Odonkor and Addo 2018 ). Though, in some instances, much higher rates of resistance were described either in general or to specific antibiotics (Adelowo et al 2014 ; Sarker et al 2019 ; Otokunefor et al 2019b ). Some of these were linked with poultry environment and thought to be a reflection of antibiotic use in these environments.…”

Potentially pathogenic multidrug-resistant <i>Vibrio</i> sp. isolated from dumpsites in Rivers State, Nigeria

“…Soil samples collected were immediately transferred to the laboratory and processed for the presence of Vibrio sp. as previously described (Otokunefor et al, 2023). In brief, a pre-enrichment was carried out using Alkaline Peptone Water (APW) and culture was subsequently done on the Thiosulfatecitrate-bile salts-sucrose (TCBS) agar using the streak method.…”

Biofilm Forming Potential of Escherichia coli from Various Sources

“…coli isolates used in this study were obtained from the bacterial collection of the Bacteriology group, Medical Microbiology Unit, University of Port Harcourt. These isolates consist of sixty previously characterized clinical (30) and non-clinical (30) Escherichia coli (Otokunefor et al, 2019).…”