Browsing by Author "Mtalika, M. I."

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Case report: Suspected Piscine Chlamydia like infection in Tanzania
(Tanzania Veterinary Journal, 2019) Matondo, A. B.; Mtalika, M. I.; Mdegela, R. H.
Ten moribund fish were received at pathology laboratory to establish the cause of sponteneous mortalities of farmed tilapia recorded in Kilosa District, Morogoro region. Post-mortem examination revealed macroscopic mucous bands connecting gills and operculum; and oval to round grey-white cysts on the gill lamella. Gill samples were collected for microscopic and bacteriological investigation. Histopathological investigation revealed gill epithelial hyperplasia and characteristic enlargement of epithelial cells infected with pale and basophilic cytoplasmic inclusions. The gross pathological changes coupled with histopathological findings recorded in this case are typical features of epitheliocystis. Furthermore, fish mortalities ceased in the farm after water replacement and reconnection of all fish ponds with direct supply of fresh water from the source. This is the first report in Tanzania describing characteristic epitheliocystis lesions. Furthermore, this report re-affirm previous findings that epitheliocystis can be managed through routine management of water quality.
Optimization of PCR-based assay for detection of tilapia lake virus in Tanzania
(Sokoine University of Agriculture, 2018) Mtalika, M. I.
Tilapia Lake Virus disease (TiLVD) is an emerging disease that affects the aquaculture industry world-wide. The disease is caused by the orthomyxo-like virus with 10 segments on its genome called Tilapia Lake Virus (TiLV). The TiLVD causes massive tilapia mortalities, and hence leads to economic loss and food insecurity. The detection of TiLV genome in Lake Victoria from previous study has prompted the need for investigation of TiLV in the region. To understand the infection status of TiLV in Tanzania, the polymerase chain reaction (PCR) - based assay was optimized in the laboratory, followed by a cross-sectional study in Mwanza, Morogoro, Pwani and Iringa regions to unravel the situation of TiLV infection in different aquaculture production systems. The internal fish organs including spleens, kidney, eggs and whole fingerling/fry were analyzed by the optimized PCR-based assay targeting segment-2 of the virus and nucleotide sequencing. The findings from the field study indicated zero prevalence of TiLV genome (N = 120). When the optimized method applied to test the samples from Lake Victoria that used in previous studies, the TiLV genome was detected. Despite the fact that, TiLV genome was not detected in the examined samples, the optimized PCR-based assay and sequencing protocols for TiLV have the potential of being used in surveillance and identification of TiLV. More studies are required to further optimize the protocols and investigate the prevalence and risk factors associated with the occurrence of TiLVD and associated infections.
Parasitic and non-parasitic conditions affecting farmed and wild cichlids in Tanzania
(Tanzania Veterinary Journal, 2018) Matondo, A. B.; Mtalika, M. I.
Infectious fish diseases are among the known contributing factor in reduced productivity of fish farming enterprises. Despite of the growing importance of global fish farming industry, research in fish and other aquatic stocks relevant to Tanzania is limited. This paper presents preliminary results of the ongoing investigation on fish mortalities which occurred in fish farm located in Kibaha District. The paper also present preliminary results of formalin fixed samples received from other parts of Tanzania. In all the samples; branchitis, gill deformity, and intracellular chlamydia like organisms were the major findings regardless of the source. Other findings include encysted trematode metacercaria in different anatomical locations accompanied with variable pathomorphological changes to the host tissues. Interestingly, mortalities ceased in the affected farm after replenishment of water supply suggesting that either poor water quality was the main predisposing factor or aggravated the observed disease conditions. Therefore maintenance of water quality and or water replacement is recommended as the first intervention measure where poor water quality is strongly suspected to be associated with mortalities in fish farms. Further studies on the pathobiological characteristic of the observed infectious organisms will provide more insights on the suspected relationships between the environmental factors in one hand and progression of the observed pathological changes in fish.