ABSTRACT
The in vitro combination effects of amoxicillin and cotrimoxazole on clinical isolates was investigated using the agar diffusion and macrobroth dilution methods. The results showed that these organisms had varied susceptibility to the different concentrations of each of these antibiotics and their combinations. The susceptibility of the isolates to the antibacterial combinations showed that they were susceptible in the following order: Streptococcus pyogenes (TD2) > Streptococcus pyogenes (TD10) > Streptococcus pneumoniae (TE10) > Salmonella typhi (TC6) > Salmonella typhi (TC2). The macrobroth assay showed a drastic reduction in the minimum inhibitory concentrations of both antibiotics. While the MIC of amoxicillin ranged between 0.1202 and 0.4808 μg/ml and that of cotrimoxazole ranged between 0.2405 and 0.9619 μg/ml, the MIC of the antibacterial combinations ranged between 0.00305 and 0.0150 μg/ml. A statistical analysis of the zones of inhibitions produced by the antibiotics and their combinations indicated that the mean differences between the zones of inhibitions were significantly diverse. This study showed that there was synergistic interaction between amoxicillin and cotrimoxazole in vitro and could be an alternative choice of therapy for the treatment of streptococcal and gastrointestinal infections in which these organisms have been implicated.
ABSTRACT
Aims: To determine the survival rates of bacteria in contaminated fresh fruit juice samples Place and Duration of Study: Biosciences and Biotechnology Department, Babcock University, Ilisan Remo, Ogun State, Nigeria, between November, 2012 and May, 2013. Methodology: Freshly extracted juice samples were obtained from intact pineapple (Ananas comosus Merr.) and watermelon (Citrillus lanatus Thunb.) were pasteurized before being contaminated with Escherichia coli ATCC 25922 and Lactobacillus acidophilus. While the pH and the sugar contents were determined at interval after being contaminated with the bacterial strains, the contaminated juice samples were sampled for 150 min to determine colony forming unit per milliliter (cfu/ml) at different sampling time. Results: In pineapple juice, the log of concentration of E. coli was reduced from 6.452 at 0 min to 5.079 at 150min. In watermelon, the log of concentration of E. coli was reduced from 6.301 at 0min to 5.954 at 150min. While the log of concentration of L. acidophilus in pineapple juice was between 6.204 at 0 min and 6.262 at 150min, its log of concentration in watermelon juice ranged between 6.228 at 0 min and 6.291 at 150min. The pH was reduced to 2.9 and 3.7 by E. coli while L. acidophilus reduced the pH to 2.5 and 3.0 for pineapple and watermelon juices respectively. After 150min, the sugar contents of pineapple and watermelon juices decreased from 1.181 and 1.060mg/ml to 0.011 and 0.004mg/ml by the E. coli while L. acidophilus reduced the sugar contents to 0.003mg/ml for pineapple juice and 0.018mg/ml for watermelon juice. The reduction in the pH values of each of the fruit juices showed that the activities of each bacterial strain resulted in increase in the production of acid in the growth medium. Conclusion: The inability of coli form (E. coli) to survive in the fruit juices suggested that the fruit juices may not harbor and/or disseminate enteric pathogens if allowed to stay for a while before packaging.