Bio

Dr. Joseph Kamau

I graduated with a PhD in 2011 from Hokkaido University, Research Center for Zoonosis Control, Japan. My PhD research focused on "Functional analysis of putative Theileria orientalis hemolysins and Molecular epidemiology of T. orientalis in Asia-Pacific region". Currently, my research interests are in Host-Parasite interaction, Genetics of diseases resistance and Molecular epidemiology of emerging and re-emerging zoonoses.

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Publications


2011

Kamau, J, Salim B, Yokoyama N, Kinyanjui P, Sugimoto C.  2011.  Rapid discrimination and quantification of Theileria orientaiis types using ribosomal DNA internal transcribed spacers. Abstract

We report the population structure analysis of Theiteiia orientalis types (Ikeda. Buffcli and Chitose). the causative agent of theileriosis in cattle and its cohorts, using ITSl and ITS2 spacers by fragment genotyping. We utilized primers flanking the two ribosomal RNA internal transcribed spacers (ITS I and ITS2). Due to varying degrees of sequence polymorphism in the ITS regions found within and between species. we exploited the insertions and or deletions in these regions which resulted in different fragment sizes. On the basis of fragment size polymorphism. we could discriminate the three commonly found types of T. orientalis. ITSl was capable of discriminating all three types (lkeda-251 bp, Chitose- 274 bp and Buffeli-269 bp) in one single reaction by fragment genotyping.In contrast. using ITS2.Ikeda (133-bp) a more pathogenic type was distinguishable from Buffeli/Chitose (139-bp). When compared with previous PCR detection method using. ITSI and ITS2 genotyping was found to be more sensitive method with high specificity in population analysis and can be deployed in molecular epidemiology studies

Thaiya, AG, Nyaga PN, Maribei JM, Ngatia TA, Kamau JPM, Kinyuru JM.  2011.  Acute, sub-chronic and chronic toxicity of Solanum incanum L in sheep in Kenya. AbstractWebsite

A study was carried out to determine the toxicity of unripe fruits of Solanum incanum L in sheep. The sheep were orally drenched with dried unripe fruits powder of S. incanum L at dose rates varying from 1,200mg to 3,600 mg/Kg /day for 9 weeks. Clinical signs were observed daily while blood with and without anticoagulant was taken weekly for haematological and biochemical analysis. Clinical signs started on day two with bloat. All sheep groups showed bloat and coughing. Signs of cerebellar hyperplasia were manifested in 25%, 75% and 25% of sheep in groups 2, 3, and 4 respectively, manifested by staggering gait, lateral recumbency, leg paddling movements, coma and death. The mortality rate was 25% for group 2 and 100% for groups 3 and 4. All sheep groups had pneumonia, froth in the bronchi, lung emphysema and congestion in the brain, liver and kidneys while groups 3 and 5 had hemorrhagic ulcers on distal abomasum to proximal duodenum and hemorrhagic enteritis from duodenum to colon. On histology, all sheep showed necrosis of the Purkinje cells of the cerebellum and Wallerian degeneration of neurons; lung emphysema and interstitial pneumonia, hemorrhagic enteritis, tubular necrosis in the kidneys and hepatocyte necrosis. The results indicate that S. incanum L is highly toxic to sheep and allowing sheep to graze on the plant is dangerous to their health.

Salim, B, Bakheit MA, Salih SE, Kamau J, Nakamura I, Nakao R, Sugimoto C.  2011.  An outbreak of bovine trypanosomiasis in the Blue Nile State, Sudan., 2011. Parasites & vectors. 4:74. Abstract

In this paper, we report an outbreak of bovine trypanosomiasis in Kurmuk District, Blue Nile State, Sudan that involved an infection with four Trypanosoma species in cattle. The outbreak occurred in June 2010 when indigenous cattle, mainly Kenana and Fulani breed types, crossed the national Sudanese border to Ethiopia and returned. A veterinarian was notified of massive deaths in the cattle populations that recently came from Ethiopia. All animals involved in the outbreak were from the nomadic Fulani group and resident local cattle were not infected and no death has been reported among them. A total of 210 blood samples were collected from the ear vein of cattle. A few samples were also collected from other domestic animals species. Parasitological examinations including hematocrit centrifugation techniques (HCT) and Giemsa-stained thin blood films were carried out. ITS1-PCR, which provides a multi-species-specific diagnosis in a single PCR, was performed.

Kamau, J, de Vos AJ, Playford M, Salim B, Kinyanjui P, Sugimoto C.  2011.  Emergence of new types of Theileria orientalis in Australian cattle and possible cause of theileriosis outbreaks., 2011. Parasites & vectors. 4:22. Abstract

Theileria parasites cause a benign infection of cattle in parts of Australia where they are endemic, but have, in recent years, been suspected of being responsible for a number of outbreaks of disease in cattle near the coast of New South Wales. The objective of this study was to identify and characterize the species of Theileria in cattle on six farms in New South Wales where disease outbreaks have occurred, and compare with Theileria from three disease-free farms in Queensland that is endemic for Theileria. Special reference was made to sub-typing of T. orientalis by type-specific PCR and sequencing of the small subunit (SSU) rRNA gene, and sequence analysis of the gene encoding a polymorphic merozoite/piroplasm surface protein (MPSP) that may be under immune selection. Nucleotide sequencing of SSU rRNA and MPSP genes revealed the presence of four Theileria genotypes: T. orientalis (buffeli), T. orientalis (ikeda), T. orientalis (chitose) and T. orientalis type 4 (MPSP) or type C (SSU rRNA). The majority of animals showed mixed infections while a few showed single infection. When MPSP nucleotide sequences were translated into amino acids, base transition did not change amino acid composition of the protein product, suggesting possible silent polymorphism. The occurrence of ikeda and type 4 (type C) previously not reported to occur and silent mutation is thought to have enhanced parasite evasion of the host immune response causing the outbreak.

2007

Kamau, JM, Mwai A, Kinyanjui PW, Iraqi FA.  2007.  Trypanotolerance effect as a result of genomic imprinting in F murine population. Abstract

African tsetse-fly transmitted trypanosomosis affects a wide range of wild and domesticated animal species. Trypanotolerance, the ability of some breeds to withstand the infection has been recognized and provides a sustainable option in animal production. While a genetic contribution, several behavioural traits are not in doubt, an attempt to find the responsible genes has proven to be complicated. One advance towards generating trypanotolerant animals has been the demonstration of an effective genetic im printing phenomenon in crossbred mice, similar to that observed following challenge. We report a novel reciprocal crossing strategy that exploits epistasis and heterosis in inbred mouse strains to identify imprinting effect controlling trypanosomosis using an F2 (129/ J x CS7BL/6) resource populations. The results indicate that genetic control for trypanotolerance is complicated and the identification of imprinting effect may provide new insights of introgressing trypanotolerance in livestock

1990

Wandera, J G;; Price, JE, Kamau JA, Ngatia TA;, Buoro IBJ;, Price JE.  1990.  Haemangiosarcoma in dogs: morphological and clinical findings. Abstract

Haemangiosarcomas in 24 dogs (average age 9 years) were found in the spleen (11 cases) or skin (9) or in bone, heart, liver or tongue (1 each); haemoperitoneum was present in 9 dogs. Metastases to the liver or lungs or both were found in 12 dogs, and to the peritoneal cavity in 8. German Shepherds (13 cases) showed particular susceptibility. Dogs that died or were killed because of tumours in the abdomen or lungs showed weakness, anaemia, weight loss and abdominal distension. Grossly the tumours contained vascular spaces lined with elongated spindle cells that were empty or contained variable amounts of blood. The spaces formed channels, or were papillary or cavernous in shape. Nests of solid tumour cells with large hyperchromatic nuclei were found in all cases.

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