Basil Nzeako

In vitro antibacterial activity of Omani and African honey

Abstract The study aims to investigate the antibacterial activity of honey obtained from different parts of Oman and compare it with that of honey obtained from elsewhere in Africa. A total of 24 honey samples (16 from different parts of Oman and eight from elsewhere in Africa) were investigated for their antibacterial activity against Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 10418) and Pseudomonas aeruginosa (NCTC 10662) using standard antimicrobial assays. Marked variations in the antibacterial activity of the different honey samples were observed. Fourteen of the 16 Omani samples and five of the eight African samples showed antibacterial activity ranked as either fair, good or excellent to at least one of the three bacterial strains tested. Both Omani and African honeys possess in vitro antibacterial activity against the three bacterial strains tested, with 25% of the samples showing excellent antibacterial activity.

Bacterial enteropathogens and factors associated with seasonal episodes of gastroenteritis in Nsukka, Nigeria.

Abstract Each year, between April and October, many children of school age and some young adults in Nsukka, Nigeria suffer from gastroenteritis. The period covers the rainy season in this part of Africa, when manured farmland occasionally is flooded. In view of the number of people suffering diarrhoea and occasionally low-grade fever, it became necessary to investigate the nature of the bacterial agents responsible. Between April and October (1996-1998), 500 loose or watery stools were collected from patients, the ages of which ranged from one month to 31 years. Stools that contained parasites were excluded from the study. Samples were cultured on 5% blood agar and 1% egg-yolk agar (both containing 10 μg/mL ampicillin), MacConkey agar, Shigella Salmonella agar and in alkaline peptone water. Bacterial growths were identified using standard bacteriological procedures. Drinking water and some fruit and vegetables prevalent during this period of the year also were cultured. Of the 500 stool samples tested, 138 (27.6%) grew a range of organisms including Aeromonas hydrophila (65 [13%]), Salmonella spp. (55 [11%]), Shigella spp. (9 [1.8%]) and enteropathogenic Escherichia coli (9 [1.8%]). Drinking water and some vegetables grew Pseudomonas aeruginosa and Enterococcus faecalis, respectively. The highest isolation rate occurred during June and July, corresponding to the period of greatest flooding of arable land. Although no enteropathogens were isolated from the fruit and vegetables examined, they contained E. faecalis – an organism found in faeces. Our findings failed to explain why 72% of the samples grew no bacterial enteropathogens.

Nature of bacteria found on some wards in Sultan Qaboos University Hospital, Oman.

Abstract This study aims to determine what objects lying in the hospital environment or brought in from outside contribute to the introduction of bacteria associated with nosocomial infections. One hundred swab specimens collected from children’s toys, sinks, door handles, telephone handsets and flowers brought into the hospital were plated on different culture media. Colonial growth on the media was purified and identified subsequently using standard bacteriological methods. Of the 100 samples cultured, 61 (61%) grew a range of bacteria including Pseudomonas aeruginosa (n=14, 23.0%), Acinetobacter spp. (n=13, 21.3%), Serratia spp. (n=9, 14.7%), Staphylococcus epidermidis (n=9, 14.7%), Stenotrophomonas maltophilia (n=4, 6.6%), Staphylococcus aureus (n=4, 6.6%), Enterobacter cloacae (n=3, 4.9%), Pantoea sp. (n=2, 3.3%), Chryseobacterium sp. (n=2, 3.3%) and Klebsiella pneumoniae (n=1, 1.6%). Although all the Serratia, Enterobacter, Klebsiella and Pantoea species isolates showed varying degrees of resistance to gentamicin, ceftriaxone, cefuroxime and cefotaxime, all were resistant to ampicillin. Chryseobacterium and Stenotrophomonas species isolates were resistant to amikacin, imipenem, gentamicin and ceftazidime, to which only three isolates of Pseudomonas species were resistant. All the staphylococcal isolates were susceptible to methicillin. Although there has been no major outbreak of a nosocomial infection in the hospital, it is strongly recommended that effective control measures (e.g., sampling the hospital water supply, disinfecting children’s toys, use of appropriate hand washing and checking some of the disinfectants for presence of bacteria) are needed. These measures are necessary to ensure that the antibiotic-resistant strains identified in this study are not allowed to spread in the hospital.