High prevalence of multidrug-resistant Gram-negative bacterial infections in Northwest Nigeria

Abstract

Introduction: There is limited data on the prevalence and antibiotic susceptibility profile of Gram-negative bacteria in northwest Nigeria. This study thus aimed to investigate the prevalence of multidrug resistant Gram-negative bacterial infections among patients in two healthcare facilities in Sokoto, northwest Nigeria.

Methods: A total of 735 non-duplicate clinical bacterial isolates were collected between January and July 2019, from among specimens processed by the diagnostic microbiological laboratory of the two hospitals. The isolates were identified using MALDI-TOF mass spectrometry and tested against a panel of sixteen (16) antibiotics using the current EUCAST guidelines.

Results: Of the 735 randomly selected bacterial isolates, 397 (54.0%) yielded Gram-negative bacteria. In the two hospitals, E. coli 104 (26.2%) and Klebsiella spp. 58 (14.6%) were the most common Gram-negative pathogens implicated in all infections. Overall, the isolates exhibited moderate to high resistance to all tested antibiotics, the lowest was observed against amikacin (7.1%). The phenotypic test for ESBL and carbapenemase enzymes showed that 48 (24.6%) and 15 (32.6%) of the isolates were positive, with 88.9% of the isolates being multidrug resistant.

Conclusions: The study documents prevalent high multidrug resistant Gram-negative bacterial infections, predominantly caused by E. coli and K. pneumoniae in Sokoto, northwest Nigeria. The isolates were mostly MDR and exhibited ESBL and carbapenemase activities. The findings of this study call for urgent implementation of infection control measures and antibiotic stewardship in our hospitals so as to limit the spread of antibiotic-resistant bacteria in our healthcare facilities.

Keywords: ESBL; Gram-negative; Multidrug resistant; Nigeria; carbapenemases.

Figure 1. Antibiotic susceptibility profile of fermentative Gram-negative bacteria. AMX- amoxicillin; AMC - amoxicillin-clavulanate; FEP - cefepime; TZP - piperacillin/tazobactam; KF - cefalotin; CRO - ceftriaxone; ERT - ertapenem; IMP - imipenem; FF - fosfomycin; F - nitrofurantoin; SXT - trimethoprim/sulfamethoxazole; AK - amikacin; CIP - ciprofloxacin; DO - doxycycline; CT - colistin; CN - gentamicin.

Figure 2. Antibiotic susceptibility profile of non-fermentative bacteria. TIC- ticarcillin; TMC - ticarcillin-clavulanate; TZP - piperacillin-tazobactam; MRM - meropenem; RIF - rifampicin; CTZ - ceftazidime; FF - fosfomycin; F - nitrofurantoin; SXT - trimethoprim-sulfamethoxazole; AK - amikacin; CIP - ciprofloxacin; DO - doxycycline; CT - colistin; CN - gentamicin.