Biofilm Formation and Resistance Profile of Microorganisms Associated with Groundwater Tap in Selected Rural Communities

Abstract

Facilities such as tap control system of groundwater can harbor microorganisms thereby leading to microbial contamination of water. Thus, the research work aimed to profile the resistance pattern and potentials for biofilm formation by bacteria isolated from groundwater sources in two selected rural communities. Swabbed samples were collected aseptically from water tap control facility for microbial isolation. Isolation was done using 10-4 and 10-5 diluent factors by pour plating technique. Biofilm formation and Kirby-Bauer disc diffusion by standard methods were employed for antibiotic sensitivity test. Pearson correlation coefficient (r) was calculated to determine the relationship between resistance and biofilm formation in the isolates. The result from the study showed that eleven (11) bacterial isolates were isolated that belong to 6 genera; Staphylococcus, Lysinbacillus, Enterobacter, Escherichia, Klebsiella and Clostridium. All isolates were found to produce biofilm in different quantities. Escherichia (9%) represents the only group with strong biofilm-forming ability, with 1.355±0.432 activity; 55% were moderate formers. Isolated bacteria showed resistance to more than one group of antibacterial agents used with the highest resistance of 81.82% in all isolates for imipenem and the least resistance observed for levofloxacin at 27.27%. Multiple Antibiotic Resistance Index ranging from 0.4-0.8 was found to be above the recommended safe limit, and ranged from 0.3-0.8 in all bacterial isolates. Water sources in the communities are heavily contaminated with microorganisms of faecal origins. It is therefore recommended that water should be treated before use, and regulatory agencies should ensure the hygiene of groundwater storage facilities and tap control.