Efficacy of aqueous plant extract in disinfecting water of different physicochemical properties.

This study explored the possibility of disinfecting water using aqueous extracts of medicinal plants. Seven medicinal plants used by Samburu herbalists for the treatment of stomach illnesses were investigated for water disinfection. Aqueous extracts of the dried powdered plant material were directly used to treat the water samples collected. Efficacy of water treatment with medicinal plants expressed as percentage reduction in bacterial colonies revealed that Acacia nilotica extract with a mean percentage reduction of 99.86% was the most effective at reducing the number of bacterial colonies. Albizia anthelmintica extract with a mean of 9.47% was the least effective at reducing the number of bacterial colonies. The study also revealed a possible interaction between plant extracts and water source (P<0.05, df=54). The results obtained in this study point out a possibility of using aqueous extracts from A. nilotica in disinfecting water of different physicochemical properties.

PRESENCE OF CRYPTOCOCCUS SPECIES IN DOMESTIC CHICKEN (GALLUS GALLUS) DROPPINGS AND THE POSSIBLE RISK IT POSED TO HUMANS IN KABIGERIET VILLAGE, NAKURU COUNTY, KENYA.

OBJECTIVE: To isolate and identify Cryptococcus from domestic Chicken dropping. DESIGN: cross sectional study. SETTING: Kabigeriet village, Olenguorone Division, Nakuru county, approximately 282 km from Nairobi, Kenya. SUBJECTS: Sixty four domestic chicken droppings were sampled in thirty two homesteads after obtaining the farmers consent. RESULTS: Two species of Cryptococcus were isolated. CONCLUSION: Domestic chicken (Gallus gallus) harbor Pathogenic Cryptococcus in their dropping and their close proximity to human habitation poses a risk of AIDS to immunocompromised persons.

The efficacy of the crude root bark extracts of Erythrina abyssinica on rifampicin resistant Mycobacterium tuberculosis.

INTRODUCTION: Tuberculosis (TB) is one of the leading causes of morbidity and mortality with a global mortality rate at two million deaths per year while one third of the world's population is infected with the TB bacillus. OBJECTIVE: To determine the efficacy of the crude extracts of Erythrina abyssinica root bark on rifampicin-resistant TB. METHODS: Crude extracts of root bark of Erythrina abyssinica, were screened against three strains of Mycobacterium tuberculosis including rifampicin-resistant TMC-331. Susceptibility tests used the disc diffusion method and were done on solid Middle brook 7H10, while the Minimum Inhibitory concentration (MICs) and minimum bactericidal concentration (MBCs) were determined by the Microtitre plate method using Middle brook 7H9 broth. RESULTS: The total crude methanol extract showed activity against all the three strains of mycobacterium used, at 50mg/ml and diameters of zones of inhibition of up to 26 mm. Erythrina abyssinica total crude methanol extract showed the highest activity on the pan sensitive strain H37Rv (0.39±0.0 mg/ml) and the rifampicin resistant strain (TMC-331) (2.35±1.11 mg/ ml) and was also active on Mycobacterium avium (0.39±0.mg/ml. The values for isoniazid were 0.25µg/ml and 9.38µg/ml for H37Rv and TMC-331 respectively, while for rifampicin the MIC value was 0.25µg/ml for H37Rv but it was not active on TMC-331. Acute toxicity test gave an LD50 of 776.2mg/kg body weight while the phytochemical analysis showed the presence of alkaloids, tannins and flavones. CONCLUSION: The conclusion from the study was that Erythrina abbyssinica has antimycobacterial activity and reasonable safety that merits further research.

Antibiotic resistant salmonella and Escherichia coli isolated from indigenous Gallus domesticus in Nairobi, Kenya.

OBJECTIVE: To characterise and investigate antimicrobial resistance of Esherichia coli and salmonella strains isolated from indigenous Gallus gallus in a leading slaughterhouse/market outlet in Nairobi-Kenya. DESIGN: A repeated cross sectional study and based on random sampling was used. SETTING: The study was carried out in a leading market outlet in Nairobi, Kenya. RESULTS: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern was the single resistance to Tet (21.43%), followed by Amp Cot Tet (14%), Aug Amp Cot Tet (4.29%), Aug Amp Cot Tet Kan Chl (2.86%), Amp Cot Tet Chl, Cot Tet (2.86%) and Crx Amp Cot Tet Chl, Crx Amp Cot Chi, Amp Cot, Aug Amp, (1.43%) respectively. The highest rate of resistance was against Tet (55.7%), followed by Cot (40%). Third in line of resistance was Amp 32.86%, followed by Aug (11.43%), low or moderate resistance was against Chl (8.57%), Kan (4.29%), and Crx (2.86%) (P<0.0002). Salmonella typhimurium recovered displayed single resistance pattern to Tet (16.67%), Gen Cot Tet (8.33%), Amp Cot Tet (8.33%), Aug Amp Cot Tet (8.33%) and Amp Cot Tet Chl (16.67%). The highest resistance was against Tet (58.3%), Cot (41.7%), Amp (33.3%), Chl (16.7%), Aug and Gen (8.3%) respectively (P<0.0001). 3.0kb and 5.6kb plasmids isolated were not transferable by conjugation. CONCLUSION: Routine surveillance at slaughter/market outlets of Escherichia coli and Salmonella enterica should be done to identify infected flocks as a regulatory procedure for food safety and security programme.

Resistance to antibiotics in urinopathogenic bacteria isolated in patients attending Kenyatta University Health Clinic, Nairobi.

OBJECTIVE: To determine the aetiological bacterial agents of urinary tract infections, within communities in Kenyatta University, and current resistance levels to commonly available therapeutic agents. DESIGN: Cross-sectional survey research design. SETTING: Kenyatta University Health Services Clinic, Nairobi. SUBJECTS: Outpatients with symptoms of urinary tract infection within the six months study duration were observed. RESULTS: Females were particularly prone to have confirmed cases of UTI. Escherichia coli were the principle aetiological agent accounting for 61.7% of the isolates. Other bacterial agents were Enterobacter agglomerans (18.7%), Citrobacter diversus (4%), Klebsiella pneumoniae (3.3%), Proteus spp. (2.1%), Pseudomonas spp. (0.1%), Staphylococcus saprophyticus (9.3%), and Streptococcus feacalis (0.7%). Over 60% of the Gram negative bacterial isolates were resistant to cotrimoxazole and ampicillin, 39% resistant to augmentin and 25% were resistant to nalidixic acid. The ceftazidime was the most efficacious antimicrobial with an Escherichia coli resistance level of 2.2% (P=0.05). Resistance to nitrofuraintoin, gentamicin, cefuroxime, norfloxacin and ciprofloxacin was demonstrated in less than 15% of the bacterial isolates. CONCLUSION: The cephalosporins, fluoroquinolones, nitrofurantoin and gentamicin have good efficacy against the uropathogenic bacteria and may be good therapeutic choices when culture results are unavailable. High resistance levels exist against cotrimoxazole, ampicillin, augmentin, and nalidixic acid. These later antibiotics should therefore be used against the uropathogenic bacteria with caution.

Antibiotic resistance and virulence factors in Escherichia coli from broiler chicken slaughtered at Tigoni processing plant in Limuru, Kenya.

BACKGROUND: Antibiotics and disinfectant use in broiler farms is a common practice and an important risk factor for promoting the emergence, selection and spread of antimicrobial-resistant micro-organisms in environment, veterinary and human medicine. OBJECTIVES: To investigate multi-drug resistance and presence of virulence related genes in Escherichia coli isolates from healthy broiler chicken at slaughter time. DESIGN: Cross sectional and laboratory based study. SETTING: Tigoni processing plant, Limuru, Kenya. RESULTS: High resistance levels were detected for most commonly used drugs like tetracycline (75.9%) and cotrimoxazole (72.4%). Other antibiotics like ampicillin (39%), chloramphenicol (13.2%) and ciprofloxacin (19%) recorded resistance levels although they are rarely used in poultry farming. One hundred and seventeen isolates showed resistance to two and more antibiotics. Different farm treatments were a significant factor for multi-drug resistance (p < or = 0.001). The E. coli isolates showed twenty-one different multi-drug resistant patterns with tetracycline/cotrimoxazole being the most common. Sixty samples were analysed for virulence related genes using multiplex PCR. Seven virulence related genes were investigated but ten isolates were positive for verotoxin and three for intimin. Serotype 0111, 0126, 06 and 078 were positive for verotoxin, 0126 and 0111 were positive for intimin. There was no significant relationship between virulence and multi-drug resistance (p < or = 0.05). CONCLUSION: The present study highlights the presence of multi-drug resistant and virulent E. coli among healthy broiler chicken in Kenya. The possible source of antibiotic resistance in the broilers is the use of recommended antibiotics which co-select resistance for other antibiotics. Surveillance for drug resistance pathogens in food products is recommended.

Microbiological quality and safety of Rastrineobola argentea retailed in Kisumu town markets, Kenya.

OBJECTIVE: To investigate faecal contamination and safety of Rastrineobola argentea sold in retail markets in Kisumu town. DESIGN: This was a repeated cross sectional study and based on random sampling. SETTING: Kisumu city, targeting six markets; Oile, Jubilee, Kibuye, Kondele, Nyalenda and Manyatta. RESULTS: A total of 60 fish samples were analysed. All the fish were found to be contaminated with E. coli, and in addition 6.67% of the fish products tested positive for Salmonella. Shigella was absent in all samples analysed. 26.53% of E. coli isolates tested were resistant to two or more antimicrobial agents tested, with the highest level of resistance detected against cotrimoxazole at 38.76%. The E. coli multiple antibiotic resistance (MAR) index was 0.084 indicating that the contamination was not originating from a high-risk source. A plasmid of approximately 5.6 kb was commonly isolated from E. coli isolates that showed resistance to ampicillin. Plasmids isolated were not transferable by conjugation. CONCLUSION: The presence of Salmonella spp and occurrence of MDR E. coli were identified as some of the possible health risks that may be associated with R. argentea displayed for sale in Kisumu city markets. This possess a real health risk through consumption or directly through contact with the fish products.

Antibacterial activity of East African medicinal plants.

In an ethnopharmacological survey, extracts of the six East African medicinal plants Entada abyssinica (stem bark), Terminalia spinosa (young branches), Harrisonia abyssinica (roots), Ximenia caffra (roots), Azadirachta indica (stem bark and leaves), and Spilanthes mauritiana (roots and flowers) were tested against 105 strains of bacteria from seven genera (Staphylococcus, Enterococcus, Pseudomonas, Escherichia, Klebsiella, Salmonella, Mycobacterium). The minimum inhibitory concentration reached by 50% (MIC50%) and 90% (MIC90) of the strains for the extracts of E. abyssinica, T. spinosa, X. caffra, and A. indica (stem bark) ranged from 0.13-8 mg/ml and from 0.5 to > 8 mg/ml, respectively. Their minimum bactericidal concentration by 50% (MBC50%) and MBC90% were all between 0.5 and > 8 mg/ml. H. abyssinica, A. indica (leaves), and S. mauritiana (roots and flowers) had MIC and MBC values > or = 8 mg/ml. Mycobacteria were not inhibited at extract concentrations of 0.5-2 mg/ml. It is concluded that plant extracts with low MIC and MBC values may serve as sources for compounds with therapeutic potency.

Activity of east African medicinal plants against Helicobacter pylori.

The activity of extracts from the East African medicinal plants Entada abyssinica (stem bark), Terminalia spinosa (young branches), Harrisonia abyssinica (roots), Ximenia caffra (roots), Azadirachta indica (leaves and stem bark) and Spilanthes mauritiana (roots and flowers) were evaluated against 12 strains of Helicobacter pylori. The most active extracts were those derived from T. spinosa with an MIC50 of 125 micrograms/ml, an MIC90 of 250 micrograms/ml and an MIC range of 62.5-500 micrograms/ml. An MIC50 of 250 micrograms/ml and an MIC90 of > 4,000 micrograms/ml was reached by H. abyssinica with a range of 125-->4,000 micrograms/ml and by X. caffra with a range of 62.5-->4,000 micrograms/ml, respectively. It is concluded that these plants contain compounds with antimicrobial activity against H. pylori.

Susceptibility of Helicobacter pylori and Candida spp. to the east African plant Terminalia spinosa.

Trees of the genus Terminalia have long been used in the traditional medicine of Kenya (East Africa). In an ethnopharmacological approach, extracts of the stem bark of Terminalia spinosa were investigated for antibacterial and antifungal activity. The extracts were active against Helicobacter pylori, with the following minimum inhibitory concentrations (MIC): MIC50 of 125 mg/l, MIC90 of 250 mg/l, and MIC-range of 62.5-500 mg/l. Yeasts of the genus Candida showed a similar susceptibility. The results indicate that the plant if a source of antimicrobial compounds with therapeutic potential.

Fungistatic and fungicidal activity of east African medicinal plants.

Extracts of the traditionally used medicinal plants Entada abyssinica (stem bark), Terminalia spinosa (young branches), Harrisonia abyssinica (roots), Ximenia caffra (roots), Azadirachta indica (stem bark), Zanha africana (stem bark) and Spilanthes mauritiana (roots and flowers) were investigated for fungistatic and fungicidal activity against Candida spp. and Aspergillus spp. by a microtitre serial dilution technique. Entada abyssinica, T. spinosa, X. caffra, A. indica, and Z. africana showed activity against various Candida species. The minimum inhibitory concentrations (MICs) ranged from 0.006 to > 8 mg ml-1 and the minimum fungicidal concentrations (MFCs) from 0.06 to > 8 mg ml-1. Extracts from S. mauritiana (both roots and flowers) exhibited no activity against Candida spp., but against Aspergillus spp., the MIC and MFC values ranged from 0.13 to 0.25 mg ml-1 and from 0.13 to 1 mg ml-1 respectively. It is concluded that the extracts contain compounds with high antifungal potency.