Extended-spectrum β-lactamase Enzymes (ESBLs) and Slime Production of some Gram-negative Bacilli Isolated from Human, Animal and Environmental Sources in Port Harcourt, Nigeria

Aim: To determine extended-spectrum β-lactamase enzymes (ESBLS) and slime production of some Gram-negative Bacilli isolated from human, animal and environmental sources in Port Harcourt, Nigeria

Study design: Cross-sectional study.

Place and Duration of Study: University of Port Harcourt Teaching Hospital, Trans-Amadi and Rumuodomaya Slaughters and Bob-D Ventures Poultry Farms, all in Port Harcourt, Nigeria, between July and December, 2019.

Methodology: This study was conducted at Port Harcourt and Obio/Akpor local government areas of Rivers State, Nigeria from 2019-2020. Hospital wastewater was taken from different sections at the two University Teaching Hospitals- University of Port Harcourt and Rivers State University Teaching Hospitals. Abattoir effluent water samples were taken at different sites from Trans-Amadi and Rumuodumaya Abattoirs. Chicken cloaca samples as well as Hand swab samples of Butchers were collected at the two Abattoirs. All samples were processed following standard procedures and identified organisms were assessed for susceptibilities to different antibiotics following Kirby-Bauer disk diffusion and Microbroth dilution methods. Isolates from the susceptibility testing with zone diameters found to be resistant to the Cephalosporins were suspected to be ESBL Positive (β-lactamase positive isolates). All isolates were also subjected to detection of slime production by Congo red agar plate method. Data were analyzed using SPSS version 22.0. Percentages and Chi square were used to summarize the data and p values less than 0.05 were considered significant.

Results: The results showed that out of the 224 isolates, 38 (17.0%) were ESBL-producing. ESBL-producers were more frequently isolated from Hospital Wastewaters (26.3%), followed by isolates from Poultry dung samples 12(24.0%) and Abattoir Effluent waters (15.0%). No ESBL-producing bacteria was recovered from the Butchers’ Hand swabs. Again, of the 38 ESBL-producing organisms, E. coli accounted for 24 (63.2%), followed by Klebsiella spp. 8 (21.1%), while Pseudomonas sp. recorded 6 (15.8%). Of the 224 isolates, 98 (43.8) were slime-producing, while 23 (60.5%) of the 38 ESBL-producing isolates produced slime.

Conclusion: ESBL and slime producing organisms (mostly E. coli) were more frequently isolated from Hospital Wastewaters compared to other sample areas.