Abstract

Medical wastewaters are potentially infectious wastes generated at health care facilities. Soil associated or under the disposed wastewater is one of the reservoirs of microbial life. The aim of this study is to determine the antibiotic sensitivity of bacteria and physicochemical constituents of medical wastewater discharged from some hospitals in Port Harcourt.  Wastewater samples were collected for the period of one (1) year from the Rivers State University Teaching Hospital, New Mile I Hospital, and Model Primary Health Centre, Potts Johnson. The bacteriological and physicochemical characteristics including heavy metal content of the wastewater samples were determined using standard analytical procedures. Data obtained were analyzed using statistical package for Social Sciences (SPSS) version 21. Mean values of counts of; total heterotrophic bacteria of samples ranged from 1.31±0.26 x10⁶CFU/ml to 1.84±0.38 x 10⁶CFU/ml across the stations, total coliform ranged from 1.18±0.21 x 10⁴CFU/ml to 1.44±0.19 x 10⁴CFU/ml, and faecal coliform ranged from 6.95±0.03 x10⁴CFU/ml to 8.45±1.34 x 10⁴CFU/ml. The following bacteria were isolated; Klebsiella oxytoca, Bacillus subtilis, Pseudomonas aeroginosa, Enterobacter siamensis, Staphyloccoccus aureus, Proteus mirabilis, Micrococcus luteus, Escherichia coli, Yersinia enterocolitica, Corynebacterium diphtheriae, Providencia vermicola, Salmonella typhi, Shigella dysenteriae and Vibrio cholerae. Physicochemical constituents of medical wastewater showed normal values except magnesium for all sample locations and bromine for Model Primary Health Centre. Antimicrobial susceptibility profile of the Gram negative isolates showed that E. coli (66.6%) and species of Proteus (50.0%), Vibrio (50.0%), and Pseudomonas (25.0%) were sensitive to Ceftazidime, Cefuroxime, Gentamycin, and Ceftriazone. However, Salmonella, Klebsiella, Enterobacter, and Yersinia species were resistant to Ofloxacin, Augmentin and Nitrofurantoin. Four Gram positive isolates belonging to the genera of Staphylococcus, Corynebacterium, Micrococcus, and Bacillus, were sensitive to Ofloxacin and Ceftriaxone. It is therefore recommended that medical wastewater should be treated before disposal since it has a tendency to pollute the subsoil and groundwater due to leaching of the pollutants and the health risks it poses to the general public.