Effect of Spices, pH and Temperature on the Survival and Multiplication of Staphylococcus aureus in Zobo Drink

This study was carried out to investigate the effects of spices, pH and temperature on the survival and growth of Staphylococcus aureus isolated from stream water samples in zobo drink. A total of 12 water samples were drawn from 3 different streams used in Ihiala Local Government Area, Anambra State, and screened for the presence of Staphylococcus aureus using pour plate method. The isolate obtained was characterized and identified using their morphological and biochemical characteristics. The effect of spices, pH and temperature on the isolate was determined by subjecting the isolate to 0.25%, 1.25% and 2.5% of spices (Zigiber officinale and Myristica fragrans), different pH ranges (3-10) and different temperatures (40C, 250C and 370C). Eleven water samples out of twelve samples drawn from the streams showed the presence of Staphylococcus aureus. The spices showed pronounced activity against the organism in both sterilized and non sterilized samples of which the activity increased significantly (P<0.05) as the concentration increased. The activity of Zigiber officinale was significantly (P<0.05) higher than that of Myristica fragrans. The maximum growth of the isolate was significantly (P<0.05) observed at pH 6 and 370C. Little or no growth was observed at 40C. This study has shown that the growth of Staphylococcus aureus in zobo drink could be controlled using Zigiber officinale and Myristica fragrans extracts at pH values other than 6, and should best be sold and consumed at refrigeration temperature (40C)

Pathogenicity Study of Dematiaceous Fungi Isolated from Chicken Feeds on Immunoincompetent Chickens

This study was carried out to investigate the pathogenicity of dematiaceous fungi isolated from chicken feeds sample in immunoincompetent chickens. A total of 40 chicken feed samples were collected from Ihiala market and screened for the presence of dematiaceous fungi using spread plate technique. The isolates obtained were characterized and identified using their microscopic and macroscopic characteristics. They were challenged orally using 0.5 ml of each of the test isolate to investigate the pathogenic potentials of each test isolate on the chickens. Dematiaceous fungi were detected in 13 chicken feed samples out of 40 chicken feed samples analysed. Alternaria alternata, Phialophora verrucosa, Madurella grisea, Madurella mycetomatis, Exophiala jeanselmei were the dematiaceous fungi detected from the feed sample. There was significant (P<0.05) decrease in the body weight of the infected immunoincompetent chickens. The total mean viable plate counts of the challenged isolates from the internal organs (heart, liver, lungs) of immunoincompetent chickens were significantly (P<0.05) higher. No count was recorded on the non-infected chicken. It was observed that the test isolate showed reasonable pathogenic features among immunoincompetent chickens and Alternaria alternata proved to be most pathogenic among the tested isolates