Phenotypic and genotypic characterization of multidrug resistant and extended-spectrum ß-lactamase-producing Enterobacterales isolated from clinical samples in the western region in Cameroon.

BACKGROUND: The 2017 World Health Organization (WHO) report has listed extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon. METHODS: A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value < 0.05 was considered statistically significant. RESULTS: A total of 152 Enterobacterales were isolated among 597 clinical samples including urine, blood, cervico-vaginal, urethral swabs and wound samples. The overall prevalence of ESBL-Enterobacterales was 29.61% (45/152). The most represented ESBL species were Escherichia coli (n = 23; 51.11%), Klebsiella pneumoniae (n = 8; 17.78%) and Citrobacter freundii (n = 6; 13.33%). CONCLUSION: This study reveals the high burden of ESBL-E among clinical samples in the regional hospital in Dschang with the most common species being E. coli and K. pneumoniae. It confirmed the high occurrence of blaCTX-M and blaTEM among ESBL-E. The study suggests that implementing antimicrobial stewardship program and real-time surveillance of antimicrobial resistance are needed in the Western region of Cameroon. Moreover, the implementation of infection prevention and control measures (IPC) is essential to curb the dissemination of these bacteria from community to hospital settings. Implementation of national action plan to fight against antimicrobial resistance at the local levels is urgently needed.

Faecal carriage of multidrug-resistant and extended-spectrum ß-lactamase-producing Enterobacterales in people living with HIV in Yaoundé, Cameroon.

OBJECTIVES: Antibiotic resistance (AR) is a global health issue with multidimensional repercussions. There is a paucity of data regarding the molecular epidemiology of multidrug-resistant Enterobacterales (MDR-E) and extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) in Africa, especially among people living with HIV (PLHIV). This study aimed at determining the prevalence, risk factors, phenotypic and genotypic profiles of MDR-E and ESBL-PE isolated from PLHIV in Yaoundé, Cameroon. METHODS: In total, samples were collected from 185 PLHIV during a three-month period (April-June 2021) at the Yaoundé Central Hospital. Stool samples and rectal swabs were collected and cultured on MacConkey agar. The API 20E kit was used for the phenotypic identification of the isolates, whereas antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. The ß-lactamase genes and genotypic relatedness were studied by PCR and ERIC-PCR, respectively. RESULTS: The prevalence of MDR-E among PLHIV was 81%, of which 39% were ESBL-PE. A high level of resistance to fosfomycin (89%), chloramphenicol (63%), and gentamicin (56%) was observed. Escherichia coli was the predominant MDR non-ESBL-PE (80.8%) and MDR ESBL-PE (73.77%). The principal ß-lactamases genes in MDR non-ESBL and MDR ESBL-PE were blaTEM (62.90%) and blaCTX-M (40.86%), respectively. Genetic fingerprinting revealed high genetic relatedness among E. coli isolates. CONCLUSION: This study shows a high prevalence of MDR-E and ESBL-PE in the gut of PLHIV in Yaoundé, with blaTEM and blaCTX-M being the most prevalent. It demonstrates the need to strengthen real-time surveillance of these resistant bacteria in order to improve management of infection among PLHIV.

Multidrug-Resistant and Extended-Spectrum ß-Lactamase (ESBL) - Producing Enterobacterales Isolated from Carriage Samples among HIV Infected Women in Yaoundé, Cameroon.

The exacerbation of antimicrobial resistance (AMR) is a major public health threat worldwide. In sub-Saharan Africa, there is a scarcity of data regarding multidrug-resistant (resistance to at least one antibiotic of three or more families of antibiotics) as well as extended spectrum ß-lactamase-producing Enterobacterales (ESBL-PE), isolated among clinical and asymptomatically healthy patients, especially in women living with HIV (WLHIV) despite their immunocompromised status. The overarching aim of this study was set to determine the prevalence and characterize genotypically multi-drug resistant Enterobacterales (MDR-E) and ESBL- PE isolated from vaginal swabs of WLHIV attending the Yaoundé Central Hospital, Yaoundé, Cameroon. A cross-sectional study was conducted among WLHIV during a four-month periods from 1 February to 31 May 2021. A total of 175 WLHIV, of childbearing age and under antiretroviral treatment were contacted. One hundred and twenty participants (120) were recruited and vaginal swabs were collected from them. After culture on Eosine-Methylen Blue (EMB) agar, the identification of Enterobacterales was performed using API 20E kit. A double-screening of ESBL-PE was performed using a combined disc diffusion method and ROSCO Diagnostica kits. An antibiotic susceptibility test was carried out by disc diffusion as per the Kirby-Bauer method and the ß-lactamase resistance genes, blaCTX-M, blaCTX-M-group1-2-9, blaTEM were molecularly characterized using a conventional Polymerase Chain Reaction (PCR). Overall, 30.83% (37/120) of the included WLHIV were colonized with Enterobacterales and the prevalence of vaginal carriage of MDR Enterobacterales among them was 62.16% (23/37). Among MDR-E isolates, the most prevalent species were E. coli (56.0%; 14/25) and K. pneumoniae (20.0%; 5/25). High rates of resistance to trimethoprim-sulfamethoxazole (96.0%; 24/25), amoxicillin-clavulanic acid (88.0%; 22/25) and gentamicin (72%; 18/25) were observed. The resistance mechanisms detected among these isolates were ESBL (48.0%; 12/25), ESBL+ porin loss (8.0%; 2/25), ESBL+AmpC (24%; 6/25), with blaCTX-M, blaCTX-M-group-1,2,9 being identified at 48.0% (12/25) for each of them and blaTEM at 72.0% (18/25). Our findings confirm the high-prevalence of MDR as well as ESBL-PE isolated in WLHIV, and suggest that a real time monitoring system of antimicrobial resistant bacteria coupled with the reinforcement of infection prevention control (IPC) strategies are needed to sustainably contain these life-threatening pathogens especially in the most vulnerable populations.