Background: The qacE gene and its variant, qacE∆1, have been associated with resistance to antimicrobials and biocides. This poses a threat to infection prevention, control and treatment. Several studies investigated this relationship with conflicting results. The aim of this research was to determine the prevalence of qacE and qacE∆1 in clinical extended spectrum β-lactamase- (ESBL) and carbapenemase-producing Klebsiella spp. and Enterobacter spp. and elucidate the association of these genes with resistance to sodium hypochlorite. Methods: This study included 216 isolates of ESBL- and carbapenemase-producing multidrug-resistant (MDR) Klebsiella spp. and Enterobacter spp. These isolates were identified by VITEK-2 analyser. The MIC and MBC of sodium hypochlorite were determined using the microbroth serial-dilution method. PCR was used to detect gene variants. A regression analysis investigated any association between qacE genotypes, MIC and MBC, as well as antimicrobial drug resistance profiles. Results: Overall, there was a high prevalence of qacE and qacE∆1 variants (84.7%; 95% CI, 79.2–89.2). There was a high prevalence of qacE∆1 (80.6%; 95% CI, 74.6–85.6) as compared to qacE (15.3%, 95% CI, 10.8–20.8). The MIC₅₀ and MIC₉₀ of the isolates ranged between 7031 mg/L and 9375 mg/L and 14,060 mg/L and 18,750 mg/L, respectively, while the MBC ranged from 48,750 mg/L to 18,750 mg/L. There was no association between qacE genotypes and high MIC and MBC as well as antimicrobial drug resistance. Conclusions: The MIC and MBC of sodium hypochlorite are higher than what is currently used for disinfection in Botswana. There is a high prevalence of qacE and qacE∆1; however, these genes do not seem to be associated with resistance to sodium hypochlorite.

Extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) and carbapenem-resistant Enterobacterales (CRE) are significant contributors to infection-related mortality in low- and middle-income countries. Colonization with ESCrE and/or CRE can precede infection and serve as a reservoir for transmission within healthcare facilities and the community.We conducted a 12-month period-prevalence study, screening patients for ESCrE and CRE upon admission to a referral tertiary hospital Emergency Department in Botswana. Rectal swabs were collected within 24 hours of hospital arrival. Colonization was identified using selective culture media and confirmed using automated susceptibility testing. Associations between ESCrE/CRE colonization, and clinical and demographic variables were analysed using univariate and multivariable logistic regression. Among 802 patients, 24.1% (n = 193) were colonized with ESCrE, and 1.5% (n = 12) with CRE. ESCrE colonization was associated with recent hospitalization (within the last six months) (aOR 1.76, 95% CI 1.11-2.79), borehole water use (aOR 3.95, 95% CI 1.12-13.87), indwelling medical devices (aOR 2.19, 95% CI 1.08-4.48), and age < 1 year (aOR 2.09, 95% CI 1.32-3.30). CRE colonization was associated with antiretroviral drug use (cOR 6.60, 95% CI 1.72-25.36). Infants (<1 year) had over three times the odds of ESCr/CR- Klebsiella spp . colonization compared to adults (cOR 3.60, 95% CI 1.82-7.13). Infant age, recent healthcare exposure, indwelling medical devices, and borehole water use were key risk factors for ESCrE colonization, highlighting the need for targeted infection prevention strategies in Botswana. The identified potential association between CRE colonization and antiretroviral drug use warrants further investigation to elucidate any possible links and drivers between HIV care and antimicrobial resistance.