Assessment of Physicochemical Qualities, Heavy Metals Concentrations and Bacterial Pathogens in Creek Road / Bonny Estuary, Rivers State, Nigeria

An assessment of water bodies for pollution is very important, especially in tropical countries, such as Nigeria. Hence, this study analysed the levels of physicochemical parameters, concentrations of heavy metals and the presence of bacteria, mainly E. coli in the water body. A total of 36 water samples were used for the analysis of physicochemical parameters, 18 for Heavy metals and 60 for bacterial detection. The physicochemical parameters were analysed both periodically (morning and evening) and seasonally (start of rainy season (November), start of rainy season (April) and middle of rainy season (July). The parameters analysed are: Potential hydrogen (pH), Temperature, Salinity, Total dissolved solid (TDS), Dissolved oxygen (DO) and Biological oxygen demand (BOD). The heavy metals were analysed only seasonally. Heterotrophic Plate Count (HPC) technique was carried out both periodically and seasonally, while the Most Probable Number (MPN) technique and Eijkman test were performed for the detection of E. coli. Then, confirmed isolates of E. coli were subjected to antibiotic susceptibility testing by disc diffusion method. All the parameters, except Temperature fell within the recommended values. The levels of the Temperature were slightly higher than the permissible values. In the morning hours, the mean values ranged from 29.89�0.10 to 30.23�0.31, while in the evenings, the mean values ranged from 30.57�0.21 to 31.80�0.56. However, the highest mean value was obtained in the evening of July. The statistical analysis showed that there was a significant difference periodically, which was observed in April and July (p=0.011; t=-4.409 and p=0.004; t=-6.124), respectively. Throughout the study, the results of the heavy metals, such as Cadmium, Mercury, Lead, Arsenic, Chromium and Nickel did not fall within the recommended values. Results of the Heterotrophic Plate Count (HPC) showed that July had the highest HPC (7.30x 106) in the mornings and 7.47x106 in the evenings. Total coliform and Total E. coli counts revealed that coliform and E. coli were found in the water body in high number. These results confirmed observations made during the sampling; dried and fresh human and animal excreta were seen along the shores of the water body. One hundred and fifty seven isolates of E. coli were subjected to antibiotic sensitivity testing and according to the results, all the isolates were susceptible to Meropenem, Imipenem and Colistin, while only two isolates were resistant to Tigecycline. The Multiple Drug Resistance (MDR) isolates were 9 (5.73 %). One hundred and twenty two isolates showed Multiple Antibiotic Resistance Index (MARI) of 0.0; that is, susceptible to all antibiotics that were tested. However, twenty one isolates showed MARI of 0.1, which means that they were resistant to one only one antibiotic.