In vitro production of trichothecenes and zearalenone by Fusarium isolates from equatorial barley (Hordeum vulgare l.) grown in Kenya

Fusarium head blight (scab) is a devastating disease of wheat and barley throughout the world. The disease has been reported worldwide wherever cereals are grown, cutting across diverse ecological and geographical distribution. In addition to being pathogenic to plants, which may cause severe crop yield reduction, many Fusarium species are also capable of producing mycotoxins deleterious to human health as secondary metabolites. Fusarium toxins are commonly detected in wheat, barley,maize, rice and beer. Traditionally malted barley (Hordeum vulgare L.) is the principal ingredient in clear beer and Fusarium toxins incidences are of major concern. Moreover, the spent grain from the brewing industry is used as feed and presence of mycotoxins can lead to harmful effects on domestic animals and also find a way into the human food chain. Studies carried out in Kenya have revealed presence of various Fusarium species with ability to produce mycotoxins and presence of Fusarium toxins in wheat and maize and beer. Based on the ubiquitous nature of Fusarium mold and the fact that barley production takes place in maize and wheatgrowing areas, this study set out to investigate the occurrence of Fusarium molds in Equatorial barley grown in Kenya and the ability of the isolates to produce selected mycotoxins. Grain samples were obtained from newly delivered barley lots originating from two regions and stored grain awaiting malting after break of dormancy from Kenya Maltings Ltd., Nairobi. The Fusarium isolates were identified to species level based on cultural and morphological characteristics. Additionally, they were screened in-vitro on rice cultures for their ability to produce Type A trichothecenes (T–2 toxin, HT–2 toxin, Diacetoxyscirpenol), Type B trichothecenes (deoxynivalenol and nivalenol) and Zearalenone. Samples from all sources were contaminated with Fusarium, but at varying magnitudes - 50%, 33.3% and 25% for barley kernels originating from Timau, Olchoro and in-storage grain with no common history of origin, respectively. The distribution of the species showed some regional specificity. F. graminearum and F. poae predominated in kernels sourced from Olchoro region. All strains of F. graminearum produced both deoxynivalenol and zearalenone. F. poae strains and F. chlamydosporum did not produce detectable amounts of the screened mycotoxins. However, two inconclusively identified isolatesof Fusarium spp. isolated from Timau samples produced deoxynivalenol only. The study revealed that a number of toxigenic Fusarium spp. do occur in Equatorial barley grown in Kenya

Molecular characterisation of echinococcus granulosus species/strains in human infections from Turkana, Kenya

Background: Cystic echinococcosis (CE) or hydatid disease is a neglected, economically important zoonotic disease endemic in pastoralist communities, in particular the Turkana community of Kenya. It is caused by the larval stage of the highly diverse species complex of Echinococcus granulosus sensu lato (s.l). The situation on the genetic diversity in humans in Kenya is not well established.Objective: To characterise Echinococcus granulosus (s.l) species/strains isolated from humans undergoing surgery in Turkana, Kenya.Design: A Cross sectional study.Setting: The Kakuma Mission Hospital and Centre for Microbiology Research, Kenya Medical Research InstituteSubjects: Eighty (80) parasite samples from 26 subjects were analysed by Polymerase chain reaction – Restriction fragment length polymorphism (PCR-RFLP) targeting the nad 1 gene for molecular characterizationResults: Two different genotypes of E. granulosus were identified from the samples analysed: E. granulosus sensu stricto (G1-G3) 85% of the samples analysed and E. canadensis G6/7 (15%). Most of the hydatid cysts (35%) were isolated from the liver. Other sites where cysts were isolated from include: kidney, abdomen, omentum, retroperitonium and the submandibular. Majority of cysts presented as CE1 (50%) and CE3B (42%) images according to WHO ultrasound classification. Both males and females were infected with E. granulosus s.s but only the females showed infection with E. canadensis G6/7. Chi-square test revealed significant difference between age of individuals and cysts classification by ultrasound. In addition, there was an association between cyst presentation (single or multiple) and genotype whereby all the E. canadensis G6/7 cases presented as single cysts in the infected persons.Conclusion: This study corroborates previous reports that E. canadensis G6/7 strain is present in Turkana, a place where initially only E. granulosus s.s (G1-G3) was known to be present and that E. granulosis (G1-G3) remains the most widespread genotype infecting humans in the Turkana community

The Green, Green Grass of Home: an archaeo-ecological approach to pastoralist settlement in central Kenya

© 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This paper considers the ecological residues of pastoralist occupation at the site of Maili Sita in Laikipia, central Kenya, drawing links with the archaeological record so as to contribute a fresh approach to the ephemeral settlement sites of mobile herding communities, a methodological aspect of African archaeology that remains problematic. Variations in the geochemical and micromorphological composition of soils along transects across the site are compared with vegetation distributions and satellite imagery to propose an occupation pattern not dissimilar to contemporary Cushitic-speaking groups further north. We argue that Maili Sita exemplifies the broad migratory and cultural exchange networks in place during the mid- to late second millennium AD, with pastoralist occupants who were both physically and culturally mobile.British Academy (2002-5 Funding) European Union - Marie Curie Initiatives (EXT grant 2007-11

Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation - a systematic review and meta-analysis

Background: Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear. Methods: We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation. Results: From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals. Conclusions: The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health

Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation - a systematic review and meta-analysis

Background: Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear. Methods: We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation. Results: From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals. Conclusions: The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health

Age-dependent acquisition of IgG antibodies to Shigella serotypes—a retrospective analysis of seroprevalence in Kenyan children with implications for infant vaccination

BackgroundShigellosis mainly affects children under 5 years of age living in low- and middle-income countries, who are the target population for vaccination. There are, however, limited data available to define the appropriate timing for vaccine administration in this age group. Information on antibody responses following natural infection, proxy for exposure, could help guide vaccination strategies.MethodsWe undertook a retrospective analysis of antibodies to five of the most prevalent Shigella serotypes among children aged <5 years in Kenya. Serum samples from a cross-sectional serosurvey in three Kenyan sites (Nairobi, Siaya, and Kilifi) were analyzed by standardized ELISA to measure IgG against Shigella sonnei and Shigella flexneri 1b, 2a, 3a, and 6. We identified factors associated with seropositivity to each Shigella serotype, including seropositivity to other Shigella serotypes.ResultsA total of 474 samples, one for each participant, were analyzed: Nairobi (n = 169), Siaya (n = 185), and Kilifi (n = 120). The median age of the participants was 13.4 months (IQR 7.0–35.6), and the male:female ratio was 1:1. Geometric mean concentrations (GMCs) for each serotype increased with age, mostly in the second year of life. The overall seroprevalence of IgG antibodies increased with age except for S. flexneri 6 which was high across all age subgroups. In the second year of life, there was a statistically significant increase of antibody GMCs against all five serotypes (p = 0.01–0.0001) and a significant increase of seroprevalence for S. flexneri 2a (p = 0.006), S. flexneri 3a (p = 0.006), and S. sonnei (p = 0.05) compared with the second part of the first year of life. Among all possible pairwise comparisons of antibody seropositivity, there was a significant association between S. flexneri 1b and 2a (OR = 6.75, 95% CI 3–14, p < 0.001) and between S. flexneri 1b and 3a (OR = 23.85, 95% CI 11–54, p < 0.001).ConclusionChildren living in low- and middle-income settings such as Kenya are exposed to Shigella infection starting from the first year of life and acquire serotype-specific antibodies against multiple serotypes. The data from this study suggest that Shigella vaccination should be targeted to infants, ideally at 6 or at least 9 months of age, to ensure children are protected in the second year of life when exposure significantly increases

Molecular characterization of Giardia duodenalis in children in Kenya

Background Giardia duodenalis is an important intestinal protozoan in humans worldwide with high infection rates occurring in densely populated and low resource settings. The parasite has been recorded to cause diarrhea in children. This study was carried out to identify G. duodenalis assemblages and sub-assemblages in children presenting with diarrhea in Kenya. Methods A total of 2112 faecal samples were collected from children aged ≤5 years and screened for the presence of Giardia cysts using microscopy. A total of 96 (4.5 %) samples were identified as Giardia positive samples and were genotyped using glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi) and β-giardin loci. Results The three markers successfully genotyped 72 isolates and grouped 2 (1.4) isolates as Assemblage A, 64 (88.9) as Assemblage B and 7 (9.7 %) consisted of mixed infections with assemblage A and B. A further analysis of 50 isolates using GDH Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) categorized 2 assemblage A isolates as sub-assemblage AII while 6 and 14 assemblage B isolates were categorized into sub-assemblage BIII and BIV respectively. A mixed infection with sub-assemblage BIII and BIV was recorded in 28 isolates. Over half (55.6 %) of Giardia infections were recorded among the children between 13 to 48 months old. Conclusion This paper reports the first data on the assemblages and sub-assemblages of Giardia duodenalis in children representing with diarrhea in Kenya