Characterization of antibiotic-resistant Staphylococcus aureus from gills and gastro-intestinal tracts of catfish (Clarias gariepinus), and water samples from Jabi Lake, Abuja, Nigeria

Background: The isolation of antibiotic resistant Staphylococcus aureus in freshwater fish poses a threat to public health because of the risk of human infections from consumption of such contaminated fish. Studies assessing antibiotic resistance of bacteria from body parts of fish and freshwater in Nigeria are sparse in the literature. This study therefore characterized S. aureus isolates from gills and gastrointestinal tract (GIT) of catfish (Clarias gariepinus), and water samples from Jabi Lake, NigeriaMethodology: Over a period of three months (April to June 2018), gills and GIT samples of 30 fish, and water samples randomly collected from 6 sites of the Lake, were cultured on Mannitol Salt Agar (MSA) for the isolation of S. aureus. Standard biochemical tests were used for bacteria identification, and antibiogram of the isolates was determined by the disc diffusion methodResults: The bacterial colony count in the gills (54.6±1.41 x 105 CFU/ml) and GIT (54.3±1.31 x 105 CFU/ml) was significantly higher (p<0.05) than the count from water sample (27.7±2.85 x 105 CFU/mL). S. aureus was isolated from 53% (16 of 30) of the gills, 57% (17 of 30) of the GIT, and 33% (2 of 6) of the water samples (p<0.05). Ninety four point one percent of S. aureus recovered from gills were resistant to ampicillin while 53.3% from the GIT were resistant to levofloxacin. S. aureus from water samples were resistant (100%) to ciprofloxacin, norfloxacin, gentamycin, amoxicillin, rifampicin, erythromycin, ampicillin and levofloxacin, and 50% were resistant to streptomycin and chloramphenicolConclusion: The presence of antibiotic resistant S. aureus in this study may be the result of selective antimicrobial pressure from anthropogenic activities as a result of abuse and overuse of antimicrobials leading to residual antibiotics in the aquatic environmentKeywords: Clarias gariepinus; gill, gastrointestinal tract; antibiotic; Staphylococcu

Perspectives of bioremediation as a panacea for ecological pollution

Analyzing the prospects of bioremediation methods and technologies as a potential clean up solution and remedy to the current environmental pollution problems facing the world today. Due to the significant rise in the number of manufacturing/ heavy industries, increase in the volume of crude oil drilling, and refining and  transportation the area of contaminated land and water by heavy metals and  petroleum hydrocarbon has consequently increased has a result of accidents, spills, dumping, etc., posing serious risk to human health and livelihood, as well disrupting the ecosystem and climate. Bioremediation methods and  technologies can mostly be combined and carried out in a multi stage process to get best results. For  instance, in the event of an oil spill the initial Raskin, Ensley, 2000; Tyagi, et al, 2010; Alonge, 2016), as opposed to previous harmful and environmentally degrading clean up procedure should involve the physical / mechanical removal of excess crude oil from the surface of the  contaminated medium, by the use of hydraulic pumps, skimmers, boomers, surfactant’s etc. At the second stage a suitable  technique of microbial bioremediation can be applied, depending on the prevailing conditions. Lastly phytoremediation techniques can be applied at the final stages to complete the cleanup and restoration of the contaminated soil or water medium.Keywords: Bioremediation, environmental pollution, phytoremediation, rhizosphere, petroleum hydrocarbon, heavy metals