Main Article Content
There is an increase in aquaculture in Kenya due to increased demand for fish as a source of white meat and increased population growth. Most fish farmers use plant-based ingredients such as peanuts, cottonseed, soybeans, maize bran and wheat as sources of protein for the fish feeds. These ingredients are very susceptible to attack by aflatoxigenic fungi. In humid climatic conditions like those found in Kisii County, growth of such fungi on fish feeds is accelerated due to absorption of moisture from the environment as a result of poor storage and sometimes improper drying. This study was conducted to determine the moulds associated with fish feeds sold in Kisii. Commercial fish feeds from five main outlets in Kisii County were sampled and analysed. Home-made fish feeds were obtained from three groups. Fungi were isolated using various media and percentage isolation determined. The results show that fifteen fungal species were associated with fish feeds sold in Kisii County. They include Mucor spp, Penicillium glabrum, Fusarium oxysporium, Aspergillus oryzae, Aspergillus flavus, Aspergillus parasiticus, Alternaria spp, Penicillium citrinum, Stachybotrys spp, Cladosporium spp, Aureobasibium spp, Eurotium spp, Aspergillus versicolor, Aspergillus fumigatus and Aspergillus niger. The aflatoxigenic fungi comprising of A. flavus, A. parasiticus and A. niger were most prevalent in fish feeds obtained from Egetuki outlet (29 %) and least prevalent in Dombetty (16.6 %). The mean differences of fungal species were statistically significant (P<0.05) in four outlets. This shows that fish feeds sold in Kisii county are contaminated with aflatoxigenic fungi.
Manning BB, Abbas HK. The effect of Fusarium mycotoxins deoxynivalenol, fumonisin, and moniliformin from contaminated moldy grains on aquaculture fish. Toxin Reviews. 2012; 31:11–15.
CAST (Council for Agricultural Science and Technology). Mycotoxins: Risks in plant, animal and human systems. Task Force Report No. 139; Ames; 2003.
NAFIS (National Farmers Information Service). Tilapia nutrition and feeding. National farmers information services, ministry of agriculture, government of Kenya; 2019.
Farmerstrend. A-Z on formulating your own floating fish feeds. Oxfarm organic Ltd.; 2016.
Samuel TO, Odunigba O. Aflatoxins associated with storage fungi in fish feeds. Ife Journal of Science. 2015;17:2.
Barbosa TS, Pereyra CM, Soleiro CA, Dias EO, Oliveira AA, Keller, KM, Silva, P, Cavaglieri LR, Rosa C. Mycobiota and mycotoxins present in finished fish feeds from farms in the Rio de Janeiro State, Brazil. International Aquatic Research. 2013;5:3.
Embaby EM, Nahed MA, Mona MA, Nasser AA, Mona MG. Mycoflora and mycotoxin contaminated chicken and fish feeds. Middle East Journal of Applied Sciences. 2015;5(4):1044-1054.
Fallah AA, Pirali-Kheirabadi E, Rahnama M, Dehkordi SS, Pirali-Kheirabadi T. Mycoflora, aflatoxigenic strains of Aspergillus section flavi and aflatoxins in fish feeds. Quality Assurance and Safety of Crops and Foods. 2014;6(4):419-424.
Greco M, Pardo A, Pose G. Mycotoxigenic Fungi and natural co-occurrence of mycotoxins in rainbow trout (Oncorhynchus mykiss) feeds. Toxins. 2015;7(11):4595-4609.
Rodriguez-Cervantes CH, Robledo-Marenco R, Sanchis V, Marin S, Giron-Perez MI. 2013. Determination of aflatoxin and fumonisin levels through ELISA and HPLC, on tilapia feed in Nayarit, Mexico. Food and Agricultural Immunology. 2013; 24(3):269-278.
Marijani E, Wainaina JM, Charo-Karia H, Nzayisenga L, Munguti J, Gnonlonfin GJB, Kigadye E, Okoth S. Mycoflora and mycotoxins in fish feed ingredients from smallholder farms in East Africa. Egyptian Journal of Aquatic Research. 2017;43: 169-176.
Njagi G. Isolation of fungal agents from formulated and commercial feeds in three fish farms in humid tropical environments of Kenya. In proceedings of the 5th Annual National Biosafety Conference, National Biosafety Authority, Nairobi Kenya; 2016.
Greco MV, Franchi ML, Rico-Golb S.L, Pardo AG, Pose GN. Mycotoxins and mycotoxigenic fungi in poultry feed for food-producing animals. Scientific World Journal. 2014;1–9.
KNBS (Kenya National Bureau of Statistics). Kenya population and housing census results, Volume 1: population by county and sub-county, Kenya; 2019.
DFKC (Directorate of Fisheries Kisii County). Annual report for 2014. Kisii County, Kenya; 2015.
Jaetzold R, Schmidt H. Farm management handbook of Kenya. Vol II. Natural conditions and farm management information part A WEST KENYA (Nyanza and Western provinces). Kenya Ministry of Agriculture. 1983;245-285.
Climate Data. Climate Kisii. Average temperature, weather by month kisii watch. Climate data Africa; 2019.
Accessed 23 April 2019.
Pitt JI, Hocking AD. Fungi and Food Spoilage. 2nd Edn. Springer, New York. 1997;19-52.
Talaro KP. Foundations in Microbiology. Macgraw Hill, New York. 2009;681.
Hocking AD. Fungi and Food spoilage. Academic Press, London. 2006;126-150.
Barnett, HL, Hunter B. Illustrated Genera of Imperfect Fungi. Saint Paul; The American Phytopathological Society; 1998.
Samson RA, Hocksra ES, Frisvad JC, Filternborg O. Methods for the Detection and Isolation of Food-borne Fungi. In: Introduction to Food-borne Fungi. The Netherlands, CBS. 1996;261-269.
Klich MA. Identification of common Aspergillus species. Centraalbureau voor schimmelcultures, Utrecht. The Netherlands. 2002;116.
Abe A, Oda Y, Asano K, Sone T. The molecular phylogeny of the genus Rhizopus based on rDNA sequences. Bioscience, Biotechnology and Biochemistry. 2006;70:2387-2393.
Muszewska A, Pawlowska J, Krzysciak P. Biology, systematics and clinical manifestations of Zygomycota infections. European Journal of Clinical Microbiology and Infectious Diseases. 2014;33;1273-1287.
Dalcero A, Mongoli C, Luna M, Ancasi G, Reynoso M, Chiacchieras S, Miazzo R, Palacio G. 1998. Mycoflora and naturally occurring mycotoxins in poultry feeds in Argentina. Mycopathologia. 1998;141:37-43.
Mahfouz ME, Sherif AH. A multiparameter investigation into adverse effects of aflatoxin on Oreochromis niloticus health status. Journal of Basics and Applied Zoology. 2015;71:48-59.
Abolagba OJ, Igbinevbo, EE. Microbial Load of Fresh and Smoked Fish Marketed in Benin Metropolis, Nigeria. Research Journal of Fisheries and Hydrobiology. 2010;5:99-104.
Juli-Anne RR, Roy PE. Molds in Fish Feeds and Aflatoxicosis. University of Florida, IFAS Extension; 2002.
Pietch C, Kersten S, Burkhardt-Holm P, Valenta H, Danickle S. Occurrence of deoxynivalenol and zearalenone in commercial fish feed: An initial study. Toxins. 2013;5(1):184-192.
Jonathan SG, Esho EO. Fungi and Aflatoxin detection in two oyster mushrooms Pleurotus ostreatus and Pleurotus pulmonarius from Nigeria. Electronic Journal of Environmental, Agricultural and Food Chemistry. 2010;9: 1722–1730.
NFSMI (National Food Service Management Institute). Safe Food Storage. The University of Mississippi; 2005.
Mutegi CK, Wagacha JM, Kimani J, Otieno G, Wanyama R, Hell K, Christie ME. 2013. Incidence of aflatoxin in peanuts (Arachis hypogaea Linnaeus) from markets in Western, Nyanza and Nairobi Provinces of Kenya and related market traits. Journal of Stored Products Research. 2013;52:118-127.
Udoh JM, Cardwel KF, Ikotun T. Storage structures and aflatoxin content of maize in five agro-ecological zones of Nigeria. Journal of Stored Products Research. 2000;36:187–201.
Rahmianna AA, Taufiq A, Yusnawan E. Effect of harvest timing and postharvest storage conditions on aflatoxin contamination in groundnuts harvested from the Wonogiri regency in Indonesia. SAT ejournal. 2007;5:1-3.
Sanders TH, Shubert AM, Pattee HE. Maturity methodology and postharvest physiology. In: Pattee HE, Young CT, Editors. Peanut science and technology. American Peanut Research and Education Society Inc, Yoakum. 1982;625-627.
Turner PC, Sylla A, Gong YY, Diallo MS, Sutcliffe AE, Hall AJ, Wild CP. Reduction in exposure to carcinogenic aflatoxins by postharvest intervention measures in west Africa: a community-based intervention study. The Lancet. 2005;365(9475):1950-1956.
Hell K, Mutegi C. 2011. Aflatoxin control and prevention strategies in key crops of Sub-Saharan Africa. African Journal of Microbiology Research. 2011;5:459-466.
Bankole SA, Adebanjo T. Mycotoxins in the West Africa, current and possibilities of controlling it. African Journal of Biotechnology. 2003;2(9):254-263.
Wu F, Khlangwiset P. Health economic impacts and cost-effectiveness of aflatoxin reduction strategies in Africa: Case studies in biocontrol and postharvest interventions. Food Additives and Contaminants. 2010;27:496-509.