Recent research has focused on natural plant products as alternative for disease control in both developed and developing countries. Medicinal plants can be a possible source for new potent antimicrobial agents to which pathogenic strains are not resistant. The present study was carried out to determine the in vitro antimicrobial activity of 14 plant species namely; Allium sativum, Aloe vera, Bryophyllum pinnatum, Cassia ocidentalis, Citrus sinensis, Euphorbia hirta, Mangifera indica, Myristica fragrans, Ocimium gratissimum, Piper guineese, Psidium guajava, Spermacoce verticilata, Vernonia amygdalina and Zingiber officinale and 3 antibiotic drugs namely; ampicillin, ciprofloxacin and streptomycin on Escherichia coli O157:H7 isolated from human clinical sample. The extracts of the plant species were prepared by cold percolation method using ethanol and water as solvents. Phytochemical analyses of the extracts of the different plant species were determined using standard methods. Agar well diffusion method was used to evaluate the antimicrobial sensitivity test of the plant extracts and that of antibiotic drugs at different concentrations ranging from 31.25 to 500 mg/ml. The minimum inhibitory concentration (MIC) of the antimicrobial agents against Escherichia coli O157:H7 was also conducted. Phytochemical analyses of the plant species revealed the presence of bioactivity principle such as alkaloids, balsam, cardiac glucoside, flavonoids, phenols, resins, saponins, tannins, terpenes and steroids. The results showed that all the antimicrobial agents exhibited inhibitory effects against the growth of the bacterial isolate at various degrees. Among the plant species employed in the study, the ethanolic and water extracts of P. guajava showed the highest inhibitory effect against the bacterium with growth inhibition mean zone diameters of 29.9 and 26.0 mm respectively at 500 mg/ml. Following P. guagava in order of inhibitory effect against E. coli O157:H7 are ethanolic extracts A. sativum, Z. officinale, V. amygdalina and M. indica with mean zones of inhibition of 21.2, 20.8, 20.3 and 19.9 mm respectively at 500 mg/ml. The results also revealed that of the three antibiotic drugs used in the study, ciprofloxacin exhibited the highest inhibitory effect against the organism with zone of inhibition of 38.6 mm, followed by streptomycin 30.2 mm, while ampicilin had the least 22.3 mm. The MIC results reveal that some of the plant species showed similar inhibitory effect against the bacterium, while the MIC results of the rest of the plants varied from one another. The in vitro study of the antimicrobial activity of the extracts of the various plant species and that of the antibiotic drugs against E. coli O157:H7 has demonstrated that certain folk medicine can be as effective as modern medicine in combating pathogenic microorganisms.

This study was carried out to determine the frequency and antibiotic susceptibility profile of bacterial agents associated with diabetic patients attending out-patients Department in Plateau Specialist Hospital Jos. Wound swabs and pus were collected from the wounds of 251 out-patients’ department (OPD) over a 14 months’ period. Subjects were recruited upon approval by the Ethical Research Committee of the UCTH and after obtaining written or oral informed consent from the subject. Samples were cultured and microbial isolates identified using standard microbiology methods.  Antibiotic susceptibility testing was carried out on the bacterial isolates. Six bacterial isolates were identified from wounds of diabetic patients viz: Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The most frequently encountered bacterial pathogen of wound infection among subjects was Pseudomonas aeruginosa (26.67%) followed by Staphylococcus aureus (23.33%) while the lowest was Klebsiella pneumonia (6.67%). The antibiotic susceptibility profile of the bacterial isolates to commonly used antibiotics ranged between 0.0% to 100%. The flouroquinolones were the most active antimicrobial agents observed among bacterial isolates from diabetic out-patients studied. S. aureus [7(100%) and 6(85.7%)] was the highest susceptible bacteria followed by P. aeruginosa [7(87.5%) and 5(62.5%)], E. coli 6(100%) against Ciprofloxacin (10%) and Augmentin (30%) respectively. Meanwhile, K. pneumonia and S. pneumonia were not susceptible each (0.0%) against Doxycycline and Chloramphenicol at 10% and 30% concentrations respectively. The study showed a high index of wound contamination with bacteria pathogens and resistance pattern to standard and commonly used antibacterial agents among diabetic out-patient from the study area. Pandukur, S. G. | Department of Science Laboratory Technology, Faculty of Natural Sciences, University of Jos.

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