9 research outputs found

    Mycoflora and mycotoxins in finished fish feed and feed ingredients from smallholder farms in East Africa

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    A total of 52 samples of finished fish feeds and ingredients were collected from smallholder farmers in Kenya, Tanzania, Rwanda and Uganda, and analyzed. Culture and molecular techniques were used to identify fungal isolates from the feedstock, and mycotoxin profiles were determined using liquid chromatography–tandem mass spectrometry. The most prevalent fungal species recovered in the samples was Asperigillus flavus (54.5%). Other fungal species recovered from the samples were Aspergillus tamarii (9.1%), Mucorvelutinosus (9%), Phoma sp. (6.1%), Aspergillus niger (6%), Eurotium rubrum (3%) and Penicillium chrysogenum (3%). Fourteen mycotoxins were identified: aflatoxins B1, B2, G1and G2, fumonisin B1 and B3, deoxynivalenol (DON) and acetyldeoxynivalenol (sum of 3-ADONand 15-ADON), ochratoxin A, roquefortine C, alternariol, T-2 toxin, and nivalenol. DON (92.9%), aflatoxins (64.3%) and fumonisins (57.1%) were the most prevalent within locally manufactured feeds, while no contamination was found in imported feed. Samples from Kenya were the most contaminated with aflatoxin (maximum 806.9 ÎŒg·kg−1). The high levels of aflatoxin and trichothecene type A and B contamination found in this study point to potential risks to fish performance and to the health of consumers of the fish and derived products

    Zoonotic surveillance for rickettsiae in domestic animals in Kenya

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    Abstract Rickettsiae are obligate intracellular bacteria that cause zoonotic and human diseases. Arthropod vectors, such as fleas, mites, ticks, and lice, transmit rickettsiae to vertebrates during blood meals. In humans, the disease can be life threatening. This study was conducted amidst rising reports of rickettsioses among travelers to Kenya. Ticks and whole blood were collected from domestic animals presented for slaughter at major slaughterhouses in Nairobi and Mombasa that receive animals from nearly all counties in the country. Blood samples and ticks were collected from 1019 cattle, 379 goats, and 299 sheep and were screened for rickettsiae by a quantitative PCR (qPCR) assay (Rick17b) using primers and probe that target the genus-specific 17-kD gene (htrA). The ticks were identified using standard taxonomic keys. All Rick17b-positive tick DNA samples were amplified and sequenced with primers sets that target rickettsial outer membrane protein genes (ompA and ompB) and the citrate-synthase encoding gene (gltA). Using the Rick17b qPCR, rickettsial infections in domestic animals were found in 25/32 counties sampled (78.1% prevalence). Infection rates were comparable in cattle (16.3%) and sheep (15.1%) but were lower in goats (7.1%). Of the 596 ticks collected, 139 had rickettsiae (23.3%), and the detection rates were highest in Amblyomma (62.3%; n=104), then Rhipicephalus (45.5%; n=120), Hyalomma (35.9%; n=28), and Boophilus (34.9%; n=30). Following sequencing, 104 out of the 139 Rick17b-positive tick DNA had good reverse and forward sequences for the 3 target genes. On querying GenBank with the generated consensus sequences, homologies of 92-100% for the following spotted fever group (SFG) rickettsiae were identified: Rickettsia africae (93.%, n=97), Rickettsia aeschlimannii (1.9%, n=2), Rickettsia mongolotimonae (0.96%, n=1), Rickettsia conorii subsp. israelensis (0.96%, n=1), Candidatus Rickettsia kulagini (0.96% n=1), and Rickettsia spp. (1.9% n=2). In conclusion, molecular methods were used in this study to detect and identify rickettsial infections in domestic animals and ticks throughout Kenya

    Global phylogenetic relationships, population structure and gene flow estimation of Trialeurodes vaporariorum (Greenhouse whitefly)

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    This study explored instructional strategies elementary-year mathematics teachers of students with emotional and/or behavioural disorders (EBD) perceived to be helpful in improving students’ performance in mathematics using a resiliency perspective (i.e., the ability to positively adapt despite experiencing significant adversity; Luthar, Cicchetti, & Becker, 2000). The researcher interviewed three elementary-year teachers to gain insight into their teaching experiences and the instructional strategies. A basic interpretive qualitative approach (Merriam, 2002) was used to understand the underlying meaning of the experiences of these mathematics teachers of students with EBD as they used evidence-based instructional strategies to improve students’ academic performance in mathematics and behaviour during instruction. A definitional focus on resiliency was the lens utilized for analyzing data generated through the interviews (Luthar, Cicchetti & Becker, 2000; Masten, 2001; Smith & Prior, 1995; Smokowski, 1998). Three themes emerged from participant interviews: ways of engaging students in learning; from dead time to active learning; and promoting positive student behaviour. Specifically, teachers reported an instructional strategy that met the needs of students of EBD which helped them obtain academic success in mathematics, and students were also better behaved in classrooms where instructional strategies employed were meeting their individual needs. These findings suggest an appropriate instructional strategy influences how students of EBD make meaning of mathematics, since teachers observed students were able to do higher thinking mathematics when strategies were in place in the classroom that met their individual needs. Teachers also shared that students were able to make good behavioural choices when they were experiencing academic success in the classroom. Practical implications of the findings, the limitations and strengths of the current study, and areas for future research are discussed

    Host Plant Strategies to Combat Against Viruses Effector Proteins

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