Prevalence of Multidrug-Resistant Bacteria Isolates in Waste Water from Different Hospital Environment in Umuahia, Nigeria

The discharge of untreated hospital waste water into the environment is a major public health concern as this could result in the environmental spread of multidrug-resistant (MDR) bacteria. The dissemination of such MDR bacteria in waste water remains unexamined in most geographical area. This study assessed the prevalence of multidrug-resistant bacterial isolates in waste water from hospital environment in Umuahia, Nigeria. Exactly 200 waste water samples were collected from various diagnostic laboratory units of Michael Okpara University of Agriculture, Umudike (MOUAU) Health Centers and Federal Medical Center (FMC), Umuahia in 250 ml screw-capped, heat-sterilized bottles. Water samples were analyzed using standard microbiological techniques. Bacterial isolates from water samples were identified with API-20E test kit. Antibiotic susceptibility test was done using Kirby–Bauer disc diffusion method. Multiple antibiotic resistance index (MARI) of isolated bacteria was determined using standard formulae. A total of 147(73.5 %) bacterial species such as S. aureus, Shigella spp, E. coli, Enterobacter spp, Proteus mirabilis, and Arizona spp were identified from the waste water samples. Bacterial isolates exhibited resistance to tetracycline, trimethoprim-sulfamethoxazole, clindamycin, nalixidic acid, vancomycin, and chloramphenicol but very susceptible to imipenem. All isolates were multidrug-resistant with MARI values ranging from 0.5 - 0.8. This study revealed the presence of MDR bacteria in hospital waste water samples in Umuahia, Abia state, Nigeria. The threat and risk of exposure to such MDR bacteria is of public health significance and raises concern over poor management and disposal of hospital waste water or effluents.