ABSTRACT
The aim of this study was to determine the incidence of multidrug resistant (MDR) and ESBL producing Gram negative bacteria isolates from abattoir effluent and poultry droppings in Benin City, Nigeria. Water samples were collected for six (6) weeks from four sites (point source (PS), confluent point (CP), upstream (UP) and downstream (DS)) within an abattoir catchment located at the Ikpoba River axis of Benin City, Nigeria. Samples of poultry droppings were also collected within the same period from the Benson Idahosa University Farm at Ugbo, Benin City, Nigeria. Bacteria species were isolated, enumerated and identified from samples using standard Microbiological techniques. The identities of selected isolates were further confirmed using 16S rRNA partial sequence analysis. The antibiogram, MDR profile and ESBL producing capacity of isolates were determined according to the description of Clinical and Laboratory Standard Institute (CLSI). While the virulence potentials of the selected isolates were determined by standard in vitro phenotypic assay for beta-haemolysis, gelatinase production and biofilm formation. The total bacterial counts for water samples collected from the abattoir catchment ranged from 7.1 × 103 ± 0.28 cfu/ml to 1.53 × 106 ± 2.12 cfu/ml. Bacterial counts in PS were significantly (P<0.01) higher than those observed in UP and DS but not with CP. Bacteria density in poultry dung varied between 5.2 × 105 ± 0.71 and 1.91 × 107 ± 2.12. One hundred and seventy-three (173) bacterial isolates were presumptively identified as Salmonella, Escherichia, Klebsiella, Enterobacter and Shigella spp. Eight (8) of these isolates presumptively identified as as Shigella spp. were confirmed as Enterobacter cloacae (2 strains), Aeromonas eucrenophila (2 strains), Aeromonas hydrophila, Klebsiella pneumoniae, Aeromonas tecta, and Aeromonas jandaei using 16S rRNA analysis. The selected isolates were all susceptible to imipenem (100%) and gentamycin (100%); whereas, they were resistant to oxacillin (100%), vancomycin (87.5%), tetracycline (87.5%), ofloxacin (75%), cefotaxime (62.5%), ciprofloxacin (62.5%), neticillin (50%) and ceftazidime (50%). Seven (7) out of the eight (8) test isolates exhibited high levels of MDR; three (3) were positive for phenotypic ESBL production; whereas all eight test isolates manifested phenotypic virulence potentials in terms of beta heamolysis, gelatinase and biofilm production. The study demonstrated that abattoir effluents and poultry droppings are considerable reservoirs of potentially pathogenic MDR and ESBL-producing Gram-negative bacteria that could contribute to community acquired infections and spread of antibiotic resistance determinants.
