Fumonisin contamination of maize (Zea mays) in aflatoxin ‘hot’ zones in eastern province of Kenya

Natural Fusarium and fumonisin contamination were evaluated in 86 stored maize samples and correlated to damaged kernels (%). Maize samples were collected from selected farmers in Aflatoxin ‘hot’ zones of Eastern province. Samples were collected from Kitui and Kibwezi districts in May to June 2008. Fusarium species were isolated and identified using morphological characteristics at Mycology Laboratory, Kenya Medical Research Institute. Fumonisinquantification was done using ELISA (RIDASCREEN ® ELISA test kit (Art. No.: R3401) at Bora Biotech, Nairobi. Colony Forming Unit (CFU) counts indicated that apart from Aspergillus a common contaminant in maize, Fusarium species infestation was also high. The most common species being F. verticillioides isolated at (39.9 %) in the two districts. Other isolated Fusarium species included, F. proliferatum (15.1 %), F. solani (9.0 %), F. anthophilium (9.0 %), F. oxysporium (15.1 %), and F. Lateritium (12.1 %). Damaged kernels analysed in this study included insect infestation, mouldy kernels, and off coloured kernels. Results showed up to 20 % of the grains were damaged in some samples. Contamination with fumonisin toxin was observed to be high. Most of the samples exceeded 1 mg / kg the maximum tolerable levels recommended by the European commission. Fusarium species count and fumonisin levels showed positive correlation (p < 0.05). In addition, there was a positive correlation between damaged kernels (%) and Fusarium species count (p < 0.05). Positive correlation was also observed between damaged kernels (%) and Fusarium species count (p < 0.05). In general, F. verticillioides and F. proliferatum were isolated in samples with the highest percentage of kernel damage and highest fumonisin concentrations. These findings indicate wide spread infestation and contamination of maize by Fusarium species and fumonisin toxins. It is apparent that apart from aflatoxins contamination there is also high level of fumonisin exposure in the high risk population necessitating urgent intervention measures to curb the long term health consequences in the population. Keywords: Fusarium spp, Mycotoxin, Fumonisin, Zea maize, Aflatoxin ‘Hot’ zone

Evaluation of bacteriological risks of barbershops in Kenyatta Market, Nairobi County, Kenya

Background: There is a growing concern that barber shops could serve as potential reservoirs of bacterial, fungal or even viral pathogens. Along with this background little is known about microbiological hazards associated with barbershops in Kenyatta Market, Nairobi County.Objective: To determine the microbiological hazards of barber shops by isolating and identifying potential bacterial pathogens from materials and equipment used in barber shops by swabbing surfaces of combs, brush, shaving machines/ clippers, customer apron, shelve and towels using moistened sterile cotton swabs.Design: Cross sectional study design was used to evaluate microbiological hazards of barber shops.Setting: Kenyatta market and its environs, barber shops.Subjects: All barbers within Kenyatta market as well as those around Ngumo and who consented to participate in the study and whose barber shops have the materials and equipment of interest.Results: A total of 56 bacterial isolates were isolated from the barbershop’s materials and equipment. The overall prevalence of pathogenic bacteria was Staphylococcus aureus 17(68.0%), E. coli 14 (56%), P. aeruginosa 14 (56.0%) and Klebsiella spp. 11(44.0%). P. aeruginosa microbial hazards were more associated with the customer aprons 6 (24.0%) , E. coli with shelves 8 (32.0%) and S. aureus with shaving machines 10 (40.0%), Klebsiella spp. was more associated with shelves, brushes and customer aprons respectively 3(12.0%). Chi square test of association showed that there was association in the type of bacteria isolated from materials and equipment at x2 = 45.710, df = 23, P =0.001. A one sample t-test analysis to test for the variation in the bacteria strains in the barber shops indicated that there was no significant difference in the number of the bacteria strains isolated in the shops (t = 1.29, P = 0.211).Conclusion: Barbering procedures particularly in Kenyatta market is associated with risks of bacterial infections both to the clients and the barbers through contaminated barber shop materials and equipment. In this regard, barbershops in Kenyatta market could serve as potential reservoir for potential bacterial pathogens for transmission to the general public. This should be a public health concern that calls for legislative mechanism to instill sanitary practices in this important public health practice

Antimicrobial properties of hugonia casteneifolia and its potential use for the control of opportunistic infections

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Dermatophyte Infections In Primary School Children In Kibera Slums Of Nairobi

Objective: To determine the prevalence and aetiology of dermatophyte infections in relation to social economic factors in primary school children in Kibera.Design: A Cross- sectional descriptive study.Setting: City council sponsored schools namely Olympic, Kibera, Ayany and Mbagathi way all in Kibera, the largest of the informal settlement within Nairobi which is home to between 700,000 - 1,000,000 inhabitamts. The study was conducted between September 2006 and February 2007.Subjects: A total of 422 primary school children from the ages of five years to 15 years were selected for the study.Results: The prevalence of dermatophytoses was 11.2% with tinea capitis being the most common type while the grey patch form being the dominant clinical manifestation. There was a significant difference (p=0.001) in dermatophytoses in different schools with Olympic primary school registering the highest prevalence (22.6%). The highestinfection rate occurred among six to eight years age bracket in both sexes compared to other age brackets (p=0.002). The genera of fungi associated with dermatophytoses were isolated indicating the number in each species as follows; T. violecium (35), T. mentagrophytes(3), T. terestre(3), T. schoenleinii(2), and T. interdigitale(1), M. canis(2),M. equinum(1) and E. flocossum(1). T. violecium was the predominant species isolated, at 35/48(71%) followed by T. mentagrophytes and T. terrestre at 3/48 (6%) each. Conclusion: The study indicates high prevalence of 11.2% dermatophyte infection among the school children in Kibera. Factors contributing to the high frequency and chronic occurrences of ring worm in this area may include poor living environment, children interaction patterns and poor health seeking behaviour. There is need for health education and public awareness campaigns among the communities in urban informal settlements on healthy seeking behaviors and hygiene in order to reducetransmission and severe clinical manifestations

Susceptibility of mycotoxigenic fungi to commercial fungicides, a potential tool for mycotoxin control in maize in Kenya

Mycotoxin contamination of food grains represents significant health and economic challenges in developing countries as well as the developed world. Mycotoxin- producing fungal species affecting maize mainly belong to the genera Aspergillus, Fusarium, and Penicillium.They pose serious phytopathological and mycotoxicological risks both at pre-harvest and post-harvest stages. Maize in Kenya has been associated with frequent outbreaks of aflatoxin contamination. A number of mycotoxin control strategies both chemical and biological have been developed as potential tools for mycotoxin control. A Laboratory based cross-sectional study was carried out in a Mycology Laboratory at the Center for Microbiology Research in Kenya Medical Research Institute, Nairobi, Kenya. A total of 138 maize samples obtained from Machakos, Nairobi, Mombasa, Kitale and Kisumu were subjected to mycological analysis. The samples were treated with the fungicides; Antracol (propineb), Milraz (propineb700g/kg and Cymoxanil60g/kg), Mistress (Cymoxanil 8% and Mancozeb 64%) and Victory (Metalaxy 80g/kg and Mancozeb 640g/kg.) before inoculation on Sabourauds dextrose agar (SDA). Infestation rates on fungicide- treated and non treated control maize kernels were scored. The susceptibility of the isolates to the four test fungicides was determined by disk diffusion technique. All the maize samples were infested by moulds and there was a significant difference in regional infestation rates (p<0.05). Maize from Mombasa had the lowest infestation of 72.5% while Nairobi was the highest with 99.1%. Fungi of the genera Aspergillus, Fusarium, and Penicillium were frequently isolated from the five regions. There was a significant reduction {p<0.05 (0.00)} of infestation rates on fungicide- treated maize compared to the untreated. Generally, 26% (n=35) and 34% (n=47) of maize samples treated with Mistress and Victory, respectively had 0% infestation while those treated with Milraz and Antracol were 10% (n=14) and 14% (n=19), respectively. Some mycotoxigenic isolates were found to be resistant to more than one of the test fungicides. However, their in- vitro antifungal activity is of great importance and could further be evaluated to determine their field efficacy for mycotoxin control in maize.Key words: Maize, Mycotoxigenic fungi, Fungicides, Susceptibility

Phytochemical analysis and antimicrobial activity of Phytolacca dodecandra, Cucumis aculeatus and Erythrina excelsa

Three medicinal plants, Erythrina excelsa, Phytolacca dodecandra and Cucumis aculeatus, collected from Siaya and Migori District in Kenya, were screened for the presence of phytochemicals. These plants have diverse compounds including phenolics, terpenoids, anthraquinones, alkaloids and flavonoids, whereby the terpenoids were the most abundant. The antimicrobial activity of the hexane, dichloromethane, ethyl acetate, methanol and water extracts from the stem barks, root barks and the leaves of selected medicinal plants were assayed against eight microorganisms. In comparison with the standard antibiotics (chloramphenicol), the dichloromethane extract presented a high activity against Pseudomonas aeruginosa ATCC 27853 and a moderate activity on Salmonella typhi (Clinical isolate). The methanol extract presented significant activity against clinical fungal isolates, Microsporum gypseum and Trychophyton mentagrophytes. The hexane and ethyl acetate extract of Cucumis aculeatus leaves were active against P. aeruginosa ATCC 27853, whereas the dichloromethane extract of Erythrina excelsa had antibacterial activity against Staphylococcus aureus ATCC 25923. Hexane, dichloromethane and water extracts of Erythrina excelsa also showed activity against Pseudomonas aeruginosa ATCC 27853. These investigations shows that various extracts obtained from Erythrina excelsa, Phytolacca dodecandra and Cucumis aculeatus could be used in vitro to inhibit the growth of some important bacteria and fungi. The above results justify the reason why these medicinal plants have been and are being used to treat the fungal and bacterial infections by the Luo community.Keywords: Phytochemicals, Erythrina excelsa, Phytolacca dodecandra, Cucumis aculeatus, antimicrobial propertie

In-vitro Antimicrobial Properties of Methanol extracts of three Medicinal Plants from Kilifi District - Kenya

Multidrug resistant microbes are a health management challenge in immunocopromised individuals. The study aimed to evaluate antimicrobial potential and toxicity of the methanol extracts of Hosludia opposita, Rhus natalensis and Combretum illairii. The plants were collected from Kilifi District and authenticated at East African Herbarium. Samples collected were extracted in methanol. Quantitative bioassay was done using disc diffusion method; minimum inhibition concentration was done using broth dilution methods. The isolates used for bioactivity testing were Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Trichophyton mentarophyte. Phytochemical screening was done using thin layer chromatograpy and cell toxicity was done using human embryonic lung cells. The H. opposita and C. illairii had terpenoids, flavonoids and anthaquinones. All the extracts were safe to the mammalian cells. Combretum illairii plant extracts had good activity against S. aureus and P. aeruginosa with inhibition zones diameters of 15.60 mm and 17.00 mm respectively. Rhus natalensis had an MIC of 6.25mg/ against both S. aureus and P. aeruginosa. The plant extracts were active against both bacteria and fungi. The result indicates that’s the plants extracts have potential for managing infections caused by the tested microbes. Isolation of compounds present and determination of their bioactivity should be done together with conservation initiatives

Actividad antioxidante, composición polifenólica y actividades antibacterianas y antifúngicas in vitro del aceite de semilla de té

The polyphenolic composition and antioxidant activity of tea seed oil from C. sinensis TRFK 301/5 (green colored) and TRFK 306 (purple colored) and C. oleifera were evaluated. The total polyphenolic content, total catechins and catechin fractions were significantly different in the oils. C. oleifera contained significantly (p ≤ 0.05) higher amounts of catechins and polyphenols than C. sinensis. C. oleifera also exhibited a higher DPPH radical scavenging activity (18.81 ± 0.46%) compared to C. sinensis (TRFK 306; 15.98 ± 0.13 and TRFK 301/5; 14.73 ± 0.47%). The antimicrobial activities of tea seed oil and two selected oils (olive and eucalyptus oil), were also evaluated against Escherichia coli, Staphylococcus aureus, Candinda albicans, Cryptococcus neoformans and Trichophyton mentagrophytes. S. aureus was significantly inhibited by the oils compared to E. coli. The oils inhibited the growth of T. mentagrophytes and C. albicans, although they had no effect on C. neoformans. Tea seed oil is a potential source of beneficial phytochemicals and potent antimicrobial agents.Se evaluó la composición polifenólica y la actividad antioxidante del aceite de semilla de té de C. sinensis TRFK 301/5 (color verde) y TRFK 306 (color púrpura) y C. oleifera. El contenido polifenólico total, catequinas totales y fracciones de catequinas fueron significativamente diferentes en los aceites. C. oleifera contenía cantidades significativamente mayores (p≤0.05) de catequinas y polifenoles que C. sinensis. C. oleifera también exhibió una mayor actividad de eliminación de radicales DPPH (18,81 ± 0,46%) en comparación con C. sinensis (TRFK 306; 15,98 ± 0,13 y TRFK 301/5; 14,73 ± 0,47%). También se evaluó la actividad antimicrobiana del aceite de semilla de té y dos aceites seleccionados (aceite de oliva y de eucalipto) frente a Escherichia coli, Staphylococcus aureus, Candinda albicans, Cryptococcus neoformans y Trichophyton mentagrophytes. S. aureus fue inhibido significativamente por los aceites en comparación con E. coli. Los aceites inhibieron el crecimiento de T. mentagrophytes y C. albicans, sin embargo, no tuvieron ningún efecto sobre C. neoformans. El aceite de semilla de té es una fuente potencial de fitoquímicos beneficiosos y potentes agentes antimicrobianos. &nbsp

Emerging azole resistance among Candida albicans from clinical sources in Nairobi, Kenya

In the recent years the number of serious opportunistic yeast infections,particularly in immunocompromised patients has increased significantly. The increased incidence of these infections has paralleled the emergence of HIV/AIDS pandemic that result in lowered resistance of the host. Azole antifungal agents has been extensively used in the management of these yeast infections. Candida albicans is one of the most frequently isolated yeasts in clinical laboratories and accounts for up to 80 % of the yeasts recovered from sites of infection. The study was set out to determine antifungal susceptibility of clinical isolates of Candida albicans and to establish the Minimum Inhibitory Concentrations (MIC) to Fluconazole, Clotrimazole, Nystatin and Amphotericin B. Laboratory based experiment were conducted at Mycology Laboratory, Kenya Medical Research Institute, Nairobi, Kenya. One hundred and thirty clinical isolates of Candida albicans were subjected to antifungal susceptibility testing. Susceptibility to Fluconazole, Clotrimazole, Nystatin and Amphotericin B was done using Broth Microdilution Technique with reference to Clinical laboratory Standard Institute (CLSI). The investigations showed that 16/130 (12.3 %) of the Candida albicans isolates were resistant (MIC ≥ 64 µg/ml) to fluconazole, 121/130 (93.1 %) of the isolates had an MIC ≤ 1 µg/ml to Amphotericin B. Of the isolates 51/130 (39.2 %) had MIC> 1 µg/ml to clotrimazole  whereas 109/130 (83.8 %) of the isolates had MIC . 1 µg/ml to nystatin. The study showed elevated MICs among Candida albicans isolates to fluconazole and clotrimazole and calls for constant antifungal resistance surveillance especially in the context of fluconazole maintenance treatment for opportunistic infections in HIV/AIDS

Fungal Infections among Diabetic Foot Ulcer- Patients Attending Diabetic Clinic in Kenyatta National Hospital, Kenya

Objective: To isolate and identify fungal pathogens associated with dermatophytoses in diabetic patients and identify the spectrum of yeasts colonising diabetic foot ulcers at Kenyatta National Hospital.Design: A cross sectional Laboratory based study.Setting: The Kenyatta National Hospital diabetic clinic.Subjects: Sixty one patients with diabetic foot ulcers from August to November 2009.Results: The five most occurring pathogens were Biopolaris hawaiiensis (5.5%), Trichophyton schoenleinii (3.7%), Aspergillus niger (3.0%), Trichophyton rubrum (3.0%), Fusarium oxysporum (3.0%). Other moulds accounted for less than 3.0%. One suspected case (0.6%) of Penicilium marneffei was isolated although it could not be ascertained due to its high containment requirement. Among the dermatophytes, the most occurring mould was Trichophyton schoenleinii (3.7%) while in non-dermatophyte was Biopolaris hawaiiensis (5.5%). Eight pathogenic yeasts were identified with C. parapsilosis (6.1 %) being the most common followed by C. famata (3.0%). Fungal infestation was highest in callus formation (78.6%).Conclusion: Fungal aetiological agents are significant cause of diabetic wound infection and may require antifungal intervention for successful management of diabetic foot ulcers