This study investigated the prevalence of Klebsiella (K.) pneumoniae isolates among clinical samples of patients in four medical centers in Lagos, Nigeria and the burden of extended-spectrum beta-lactamases (ESBL) and carbapenem-resistant K. pneumoniae (CRKP) strains. Different samples (stool, blood, urine, wound swabs and nasal swabs) from 127 patients with suspected Gram-negative infections based on on-site performed Gram-stain from four public hospitals between March and September 2015 were analyzed. K. pneumoniae was identified in 43 (34%) patients. Resistance rates of these 43 strains according to the CLSI breakpoints were as followed: cotrimoxazole (90.7%), cefuroxime (74.4%), ofloxacin (55.8%), ceftazidime (46.5%), and cefixime (35%). Three isolates (7%) were resistant to imipenem. All isolates were susceptible to amoxicillin/clavulanic acid and nitrofurantoin. The prevalence of ESBL-producing, MDR and CRKP strains was 69.8%, 62.8%, and 7.0%, respectively. Of the ESBL-producing isolates, two K. pneumoniae isolates obtained from urine harbored both blaSHV and blaCTX-M-1, and a third isolate from urine harbored only the blaCTX-M-1. This study revealed the emergence of CRKP isolates and blaCTX-M-1 and blaSHV co-harboring K. pneumoniae strains in Lagos hospitals. The emergence of CRKP strains is an early warning signal for carbapenem antibiotics’ prudent use with concern for their efficacies.

Backgrounds:The burden of bacteremia in febrile cases is still poorly understood in Nigeria as in many sub-Saharan African countries due to diagnostic limitations. This study aimed to determine the prevalence of Salmonella bloodstream infections and antimicrobial resistance patterns of bacterial isolates recovered from febrile patients in Lagos, Nigeria. Materials & Methods: A total of 300 blood samples were collected from febrile patients attending four medical centers in Lagos during August 2020 to July 2021. Clinical isolates were identified using API 20E kit. qPCR was used to detect Salmonella isolates in positive blood culture samples using a specific primer set. All isolates were subjected to antimicrobial susceptibility tests using standard procedures. Findings: Totally, 55 bacterial isolates belonging to six bacterial genera were identified, including Salmonella (n=4, 7.27%), Klebsiella species (n=23, 41.82%), Escherichia coli (n=6, 10.91%), Proteus species (n=13, 23.64%), Serratia species (n=7, 12.73%), and Citrobacter species (n=2, 3.64%). In this study, the detection rate of Salmonella isolates in positive blood culture samples using qPCR and invA gene primer set was 100%. Salmonella isolates were %100 resistant to ceftazidime, cefotaxime, and doripenem. Multidrug resistance (MDR) was observed in Salmonella and other bacterial isolates. Conclusion:In this study, qPCR using the invA primer set was found to be highly specific for Salmonella detection. All the bloodstream bacterial pathogens in this study were MDR; thus, there is a need for continuous evaluation of antibiotics in medical settings. Further molecular studies on these bacterial isolates is essential.

Different samples (i.e. stool, blood, urine, sputum, wound swabs, nasal swabs etc.) from 127 patients with suspected gramnegative infections based on on-site performed Gram-stain from four public hospitals between March and September 2015 in Lagos, Nigeria were analysed. Klebsiella (K.) pneumonia was identified in 43 (34%) patients. Resistance rates of these 43 strains according to the CLSI breakpoints were as followed: cotrimoxazole (90.7%), cefuroxime (74.4%), ofloxacin (55.8%), ceftazidime (46.5%), and cefixime (35%). Three isolates (7%) were resistant to imipenem. All isolates were susceptible to amoxicillin/clavulanic acid and nitrofurantoin. The prevalence of ESBL-producing and carbapenem resistant strains (CRKP) was 69.8% and 7.0%, respectively. Of the ESBL producing isolates, two K. pneumoniae isolates obtained from urine harbored both blaCTX-M-1 and blaSHV and a third isolate from urine harbored only blaCTX-M-1. Emerging of CRKP strains is an early warning signal for the prudent use of carbapenem antibiotics in concern to their efficacies.