A study of the antimicrobial resistance and transfer of resistance among organisms isolated from lettuce (Lactuca sativa) leaves in three localities in southwest Nigeria.

The bacterial flora of lettuce from western Nigeria were investigated for their identity, antimicrobial resistance, and ability to transfer such resistance to other organisms. The isolated contaminants were mostly Gram-negative organisms of the Enterobacteriaceae family, which included Enterobacter species and E. coli. The organisms were resistant to a wide range of antimicrobials and they exhibited multiple antimicrobial resistance phenotypes. Common resistance phenotypes observed included those to beta lactam antibiotics, trimethoprim, and streptomycin. A majority of the isolates had minimum inhibitory concentration of trimethoprim over 1,000 mg/L and they were shown to possess the ability to transfer their resistance to a plasmidless E. coli strain. The results of the authors' study underscore the contributory role of lettuce in the dissemination of antimicrobial resistance in the Nigerian community.

Antioxidant and antibacterial activities of flavonoid glycosides from Ficus exasperata Vahl-Holl (moraceae) leaves.

BACKGROUND: Ficus exasperata Vahl-Holl (Moraceae) leaves are used for infectious and inflammatory conditions in many West African Countries. However, there is need for more phytochemical studies to justify the ethnomedicinal uses of the plant. MATERIAL AND METHODS: The crude 50% aqueous ethanolic extract of the leaves was partitioned successively between water and; n-hexane, ethyl acetate and n-butanol. The fractions were subjected to antimicrobial activity using agar diffusion test. n-Butanol fraction, which showed both antimicrobial and radical scavenging activities was subjected to repeated chromatographic fractionation on both silica and Sephadex LH-20 columns. Each stage of the purification was monitored by thin layer chromatographic diphenylpicryl hydrazyl autographic assay. Three compounds were isolated. The structures of the compounds were elucidated using spectroscopic methods, shift reagent studies, acid hydrolysis, and by comparison with literature data. RESULTS: The compounds were identified as apigenin C-8 glucoside (1), isoquercitrin-6-O-4-hydroxybenzoate (2) and quercetin-3-O-ß-rhamnoside (3). The solvent fractions and isolated compounds were found to inhibit the growth of Gram +ve organisms only. CONCLUSION: These flavonoid glycosides are being reported in this plant species for the first time. Their weak in vitro antimicrobial activity suggest the flavonoids may be acting as pro-drug. The radical scavenging activity of the compounds may justify some of the ethnomedicinal uses of the plant as free radicals are implicated in the aetiology of many inflammatory diseases.

The bacteriological quality of different brands of bottled water available to consumers in Ile-Ife, south-western Nigeria.

BACKGROUND: The upsurge in the demand for bottled water has prompted the interest of many manufacturers in the production of bottled water and very many water bottling companies are therefore involved in its production. These range from large scale multinational companies to medium scale business enterprises, institutional and government business investment companies as well as small scale entrepreneurs. There is however little information on the comparative quality of bottled water brands produced by different classes of water bottling companies in Nigeria. This study was undertaken to determine the bacteriological quality of brands of bottled water available to consumers in Ile-Ife. METHODS: Forty-three samples of bottled water comprising of three batches each of thirteen bottled water brands and two batches of two brands were purchased and analyzed for total bacterial count, presence of coliform and the presence of other bacterial indicators of drinking water quality. RESULTS: Only 67.4% of the water samples representing the products of 10 companies or 66.7% of the brands had heterotrophic counts within the acceptable limits. Coliforms present in 100 ml of water were detected in 26.7% of the bottled water brands. Other indicator organisms detected included Staphylococci isolated from 27.9% of the samples (33.3% of the brands) and specifically Staphylococcus aureus found in four brands constituting 14% of the samples. Pseudomonas strains were consistently detected in consecutive batches of three brands of the water samples. CONCLUSIONS: Bottled water samples produced by the large scale multinational producers were of acceptable bacteriological quality unlike those produced by most small companies. SIGNIFICANCE AND IMPACT OF STUDY: There is need for a greater control of water bottling processes carried out by commercial bottled water producers in Nigeria.

Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value.

Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers.