| Title |
Seasonal Abundance and Distribution of Vibrio Species in the Treated Effluents of Wastewater Treatment Facilities in Suburban and Urban Communities of Eastern Cape Province, South Africa |
| Author |
Etinosa O. Igbinosa1, Chikwelu L. Obi2, and Anthony I. Okoh1* |
| Address |
1Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa, 2Deputy Vice-Chancellor Office, Walter Sisulu University, Umthata 5117, South Africa |
| Bibliography |
Journal of Microbiology, 49(2),224-232, 2011,
|
| DOI |
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| Key Words |
environmental parameters, public health, Vibrio pathogens, treated effluents |
| Abstract |
We assessed the seasonal abundance and distribution of Vibrio species as well as some selected environmental parameters in the treated effluents of two wastewater treatment plants (WWTP), one each located in a suburban and urban community of Eastern Cape Province, South Africa. Vibrio population density ranged from 2.1×101 to 4.36×104 CFU/ml in the suburban community and from 2.80×101 to 1.80×105 CFU/ml in the urban community. Vibrio species associated with 180 μm, 60 μm, and 20 μm plankton sizes were observed at densities of 0-1.36×103 CFU/ml, 0-8.40×102 CFU/ml, and 0-6.80×102 CFU/ml, respectively at the suburban community’s WWTP. In the urban community, observed densities of culturable Vibrio were 0-2.80×102
CFU/ml (180 μm), 0-6.60×102 CFU/ml (60 μm), and 0-1.80×103 CFU/ml (20 μm). The abundance of free-living Vibrio species ranged from 0 to 1.0×102 and 1.0×103 CFU/ml in the suburban and urban communities’ WWTPs, respectively. Molecular confirmation of the presumptive Vibrio isolates revealed the presence of
V. fluvialis (41.38%), V. vulnificus (34.48%), and V. parahaemolyticus (24.14%) in the suburban community effluents. In the urban community molecular confirmation revealed that the same species were present at slightly different percentages, V. fluvialis (40%), V. vulnificus (36%), and V. parahaemolyticus (24%). There was no significant correlation between Vibrio abundance and season, either as free-living or planktonassociated entities, but Vibrio species abundance was positively correlated with temperature (r=0.565; p<0.01), salinity, and dissolved oxygen (p<0.05). Turbidity and pH showed significant seasonal variation (p<0.05)
across the seasons in both locations. This study underscores the potential of WWTPs to be sources of Vibrio pathogens in the watershed of suburban and urban communities in South Africa. |
