Bacteriological analysis of potable water in areas with reported cholera outbreaks in Ogun, Oyo and Lagos States, Nigeria

Background: Cholera outbreaks, reported yearly in Nigeria, are a public health concern and transmission is attributed to drinking of contaminated water and poor sanitation. Objective: To conduct a bacteriological analysis of potable water in areas with reported cholera outbreaks in Ogun, Lagos and Oyo States. Methods: Water samples collected from the study areas were examined physically, cultured in MacConkey broth and Alkaline peptone water to determine the most probable number (MPN) of Coliforms and isolate Vibro species respectively. Bacteria were cultured from the broths and were identified using standard methods. Results: All the other water samples examined were colourless, odourless, tasteless and lack particles except the well water which had yellowish brown colouration (4; 8%) and contained visible particles (5; 30%). The presumptive total coliform count ranged between < 3 and 1,100 MPN /100ml. Enterobacter gergoviae (34; 47.2%), Escherichia coli (16; 22.2%), Klebsiella pneumonia (7; 9.7%), Sarratia liquefaciens (6; 8.3%), Vibrio parahaemolyticus (5; 6.9%), Citrobacter diversus (2; 2.8), Klebsiella oxytoca (1; 1.4%) and Enterobacter aerogenes (1; 1.4%) were isolated from 33.5% of the water samples. The level of contamination of water sources within the different study areas was significant (p<0.001). Vibrio cholerae was not isolated, but Vibrio parahaemolyticus was isolated from 5 (10%) of the well water samples. Thermo-tolerant Coliforms were also identified from some samples. Conclusion: The well water samples were grossly contaminated with coliform bacteria and Vibrio parahaemolyticus and should be treated before drinking

In Vitro Antimicrobial Studies of Plait Aqueous Extracts of Some Nigerian Medicinal Plants

Medicinal plants have been used by man to treat various kinds of infections without scientfic pror of their efficacy. The Antimicrobial activities of aqueous extracts of four Nigerian medicinal plants namely: Solanum americanum, Euphorbia hirta, Cassia occidentalis and Telfaria occidentalis were investigated against a wide range of isolated strains of bacteria by the disc diffusion method. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts were also determined on the susceptible organisms. These plant extracts are used in Nigeria folklore medicine to treat infections of microbial origin. Aqueous extracts of the investigated plants showed antibacterial activities against different pathogenic bacteria. Among the pathogenic organisms  used, Staphylococcus  aureus, Pseudomonas aeruginosa, Klebsiella  pneumoniae and Escherichia coli were susceptible to three of the aqueous extracts used at concentrations of 100μg/ml. The plant  extracts demonstrated broadspectrum antibacterial activity against the microorganisms tested. The Minimum Inhibitory Concentration (MIC) of Solanum americanum was between 6.3μg/ml to 25μg/ml against these test organisms while MIC of Cassia occidental is ranged between 12.5μg/ml to 25μg/ml, while that of Eurporbia hirta ranged between 25μg/ml and 50μg/ml. The Minimum Bactericidal Concentration (MBC) of Cassia occidentalis and Euphorbia hirta was 25μg/ml for all the bacterial isolates, while that for Solanum americanum was 12.5μg/ml for Pseudomonas aemginosa and Staphlococcus aureus and 25μg/ml for E. coli and Klebsiella pneumoniae. Keywords: Antimicrobial activity, Medicinal plants, Minimum Bactericidal Concentration, Minimum Inhibitory Concentratio