Survey of Extended-Spectrum β-lactamase Producing Gram-negative Bacteria in Lower Respiratory Tract Infections in Kebbi State, Nigeria

Abstract

Extended-spectrum beta-lactamase (ESBL) producing Gram-negative bacteria are a significant public health concern, particularly in developing countries. This study was designed to survey for extended-spectrum β-lactamase-producing Gram-negative bacteria in patients with lower respiratory tract infection in Kebbi State, Nigeria. Three hundred and fifty (350) sputum samples were collected from patients attending six different hospitals in Kebbi State. The bacterial isolates were identified using conventional biochemical tests and then confirmed using a commercial biochemical test kit (MICROBACT). Antimicrobial susceptibility test was determined using the disc diffusion method. The bacterial isolates that were resistant to third-generation cephalosporins were confirmed for ESBL production using the double disk synergy test. Out of 350 sputum samples analysed, 74 (21.1%) were found to be gram-negative bacteria. Also, out of 74 different gram-negative bacterial isolates identified, 50(67.6) were identified to be ESBL producers.  ESBLs were seen among Aeromonas hydrophila 6(100%), Pseudomonas aeruginosa 6(100%), Burkholderia pseudomallei 3 (100%) and Klebsiella pneumoniae 19 (79.2%). Other ESBL-producing bacteria recorded included Proteus vulgaris 2 (66.7%), Klebsiella oxytoca 8(53.3%), Acinetobacter baumannii 2(40%) and Escherichia coli 4 (33.3%). It was also recorded from this study that ESBL-producing bacteria were detected in all the hospitals studied, but the highest level of ESBL production was detected at Sir Yahaya Memorial Hospital (SYMH) and Martha Bamaiyi General Hospital, Zuru (MGHZ), with a percentage occurrence of 11(22%), respectively. In conclusion, it was observed that high levels of ESBL production were detected among Aeromonas hydrophila 6(100%), Pseudomonas aeruginosa 6(100%), Burkholderia pseudomallei 3 (100%) and Klebsiella pneumoniae 19 (79.2%).