Microbiological Assessment of Irrigation Water That Serves as Watershed for Wastewater in Osogbo and Its Impact on Fresh Vegetables

Abstract

This study was designed to investigate the microbiological safety of irrigation water along with waste effluents and their impact on vegetables. Irrigation water samples situated amongst hospital, abattoir and petrol station were aseptically collected with fresh vegetables simultaneously. Physicochemical, microbiological and molecular studies were carried out using standard methods. The result of the physicochemical analysis shows that the irrigation water samples temperature ranged from 23.4-24.8oC while the pH ranged from 7.24-7.51. The bacterial count of isolates showed that the water samples were highly contaminated with microbial count ranging from 9×102 to 151×104cfu/ml which has exceeded the WHO microbial count recommendation for potable water (10×103cfu/ml). Organisms isolated from both water and vegetable samples were all pathogenic. Antimicrobial susceptibility test results showed that all the isolates were susceptible to cefepime and oxacillin while 60% of the isolates were multidrug resistant. Aeromonas taiwanensis was recovered from both the water and vegetable samples. This however calls for huge attention as Aeromonas species are potential pathogenic organisms that can be isolated from both clinical and polluted environmental samples such as wounds, petrol and abattoir litters. Therefore, it can be concluded that wastewater effluents should not be channeled directly into surface water bodies without prior safety treatments.