Abstract: Tsetse flies are vectors of African trypanosomes, the protozoan agent of devastating disease, trypanosomiasis that afflicts both humans and animals. Currently, there is no promising vaccine in the horizon and treatment efforts are further constrained by the rapid increase in parasite drug resistance observed in patients. In addition, little effort is being made to develop new and effective drugs. Alternative methods to control trypanosomiasis and its transmission are therefore requ...
Abstract: The tsetse fly is an insect of great economic importance to man as a vector of both human and animal trypanosomiasis. Trypanosomes are ingested by the tsetse fly vector with a bloodmeal taken from .an infected host. In the midgut, these parasites are exposed to a hostile environment which comprises of lectins/ trypanoagglutinins, proteolytic enzymes, trypanolysins and other unknown factors. Lectins or agglutinins are a group of proteins of non-immune in origin, that bind carbohydra...
Abstract: Soil is the primary reservoir for fungi of which Aspergillus and Fusarium species are the main causal agents of maize ear rot and mycotoxin production. Season and cropping systems are known to influence soil fungal community structure. It is imperative to establish the distribution and density of soil fungal communities as a requisite for formulating strategies for management of ear rot infections and mycotoxin contamination. The current study was carried out to investigate the dis...
Abstract: Malaria is a strong selective force in the human genome, selecting genes for resistance to disease in human populations living in malaria endemic areas. Selection by malaria has generated genetic variations, providing evolutionary driving force mediating polymorphisms such as Glucose-6-Phosphate Dehydrogenase deficiency and sickle-cell anaemia. Genes encoding erythrocyte receptors of Plasmodium falciparum especially the sialoglycoproteins, glycophorins A, B and C, which are the mai...
The main purpose of this study was to establish the pathway(s) by which PEP from glucose catabolism is catabolised , the end products formed in the presence and absence of SHAM, the sub cellular localisation of some key enzymes involved in PEP catabolism and to partially characterise PEPCK in bloodstream T. congolense.
Abstract: The relationship between Pseudotheraptus wayi (cashew pest), Anacardium occidentale (cashew plant), and Oecophylla longinoda (natural enemy) is a trophic interaction that is very important in cashew nut production. However, the chemical ecology of the interaction, specifically between the cashew plant and natural enemy as well as the pest and natural enemy was little investigated. Based on the hypothesis that both interactions were mediated by chemical signals, the objective of thi...
Abstract: In a previous study using three plant species (maize, sorghum and Napier grass), naïve gravid B fusca females significantly preferred sorghum and maize over Napier grass for oviposition a phenomenon, which was partly related to plant physical characteristics such as leaf surface texture and sheath toughness. The purpose of this study was therefore to determine the importance of plant chemical characteristics (volatiles as well as surface compounds) in host selection for ovipositio...
Abstract: Ticks are haematophagous ectoparasites capable of transmitting diseases to vertebrates and, therefore, constitute a threat to human, livestock and wildlife health. Though synthetic chemical acaricides have made a tremendous impact over the years in the control and management of the vector on livestock, ticks have developed resistance to most of them. In addition, the chemicals are toxic to non-target organisms. In some parts of Kenya, powdered parts of some plants, including those ...
Abstract: The braconid larval parasitoid Cotesia flavipes Cameron (Hymenoptera: Braconidae) was introduced into Kenya from Pakistan and India for the control of the exotic crambid stem borer Chilo partellus Swinhoe (Lepidoptera: Crambidae). In Africa, maize fields are usually islands surrounded by land occupied by wild gramineous plants. Many of the wild plants harbour borer species not found on crops. It is not known if the exotic parasitoid C. flavipes follows these borers into the wild ha...
Abstract: Anopheles gambiae mosquito, the principle Afro-tropical vector of malaria, has been documented in habitats with heavy metals in excess of natural loads. The mosquito has also displayed resistance to most conventional insecticides, and potential to resist challenges by heavy metals. Investigations were conducted in strains of An. gambiae ss, in which tolerance to cadmium and lead heavy metals were established. This study was undertaken to determine any putative relationship between ...
Abstract: Tsetse flies are important agricultural and medical vectors of African trypanosomes, the causative agents of trypanosomosis in humans and animals. The life cycle of the protozoan parasite Trypanosoma, in its invertebrate vector begins when the tsetse fly feeds on an infected mammalian host. An important step in the establishment of tsetse midgut infection involves transformation of bloodstream-form trypanosomes into procyclic forms. This process is mediated by a wide variety of fac...
Abstract: Rift Valley Fever (RVF) is a mosquito borne viral infection, first reported in the Rift Valley province of Kenya in 1912 and identified in 1931. Major outbreaks have been reported in Kenya in 1997/1998 and 2006/2007. Baringo, Garissa and Kilifi district of Kenya were hot spots in the last major RVF outbreak that occurred in the country in 2006/2007. Investigations were conducted during the outbreak to establish putative mosquito vectors and vertebrate host of RVF virus. Engorged fe...
Abstract: Several studies have shown that Rhipicephalus appendiculatus from geographically isolated areas differ in their susceptibilities to Theileria paIva, the haemoprotozoan causative agent of East Coast Fever. In Kenya, R. appendiculatus from Muguga have been reported to be less susceptible to T parva infection than those from Rusinga Islands. As the same tick species from different areas shows variation in vector competence, it was considered to be of epidemiological interest to determ...
Abstract: This research work on the role of termites in an arid ecosystem covered eleven months (August 1981 to .June 1982). It was conducted at the site of the UNESCO integrated project in Arid Lands (UNESCO - !PAL} . This area is in Western Marsabit district, Kenya . About 80% of this area is semi-arid thorn bush scrubland and receives annual rainfall from about 100 to 600 mm. A survey of the termite fauna as a whole was carried out around most of the !PAL Field camps. Main investigation s...
Abstract: Cellulolytic microorganisms such as fungi and bacteria are responsible for much of the cellulose degradation in soils. Despite this vast number of cellulase producers, there is a deficiency of microorganisms that can produce significant amount of the three cellulase enzyme specifities i.e. endoglucanases, exoglucanases and cellobiases to efficiently degrade cellulose to fermentable products. Little emphasis has been given to cellulase production from bacteria despite their extremel...