Browsing by Author "Anjili, Christopher O."
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Item Characterization and comparison of leishmania-like isolates from rodents, lizards and sand flies caught at Masinga location in Machakos district, Kenya(African Journal of Health Sciences, 2011-06) Kinuthia, Geoffrey K.; Lugalia, Reuben; Mwanyumba, Panuel J.; Ngeiywa, , Moses M.; Anjili, Christopher O.; Tonui, Willy K.A laboratory based study was designed to characterize 43 cryo-preserved Leishmania-like flagellates. These Leishmania-like flagellates were originally obtained from non-human hosts that included spiny mice (Acomys subspinosus), plated lizards (Gerrosaurus major) and sand flies of the Genus Sergentomyia caught at Masinga location, Machakos District in Kenya. Morphological features and isoenzyme banding patterns of the flagellates were studied. The isoenzyme markers which were used for isoenzyme electrophoresis included Malate dehydrogenase (MDH), Phosphoglucomutase (PGM), Glucose phosphate isomerase (GPI), Glucose 6-phosphate dehydrogenase (G6PD), Malic enzyme (ME), 6 phosphogluconate dehydrogenase (6PGD) and Mannose phosphate isomerase (MPI). The isoenzyme banding patterns of the flagellates’ lysates were compared with those of six WHO Leishmania reference strains and those of seven well characterized reference strains of Trypanosoma, Crithidia, Herpetomonas and Leptomonas species. The results showed that the morphological changes of the Leishmania-like flagellates in the growth medium were indistinguishable from those of Leishmania WHO reference strains used. The isoenzyme profiles of the flagellates were all distinguishable from the reference strains used except for isolate NLB-1236 from G. major which had an enzyme profile identical to that of L. tropica (NLB-305) in 6 enzymes (MDH, GPI, MPI, ME, PGM, and G6PD). The banding pattern of isolate NLB-1261 from A. subspinosus was indistinguishable from that of L. major (NLB-326) in 3 enzymes only (MDH, GPI and ME) while isolate NLB-1231 from A. subspinosus had an enzyme profile identical to those of L. tropica (NLB-305) and L. arabica (NLB-664) in six enzymes (MDH, GPI, ME, PGM, MPI, and 6PGD). More than 80% of the Leishmania-like flagellates had enzyme profiles indistinguishable from each other, in all the isoenzyme markers. The morphological traits of the flagellates suggested that they were Leishmania or strains closely related to Leishmania. Isoenzyme analysis suggested that Sergentomyia sand flies most likely feed on both lizards (reptiles) and rodents (mammals). There is need to carry further investigations on NLB-1236 (from plated lizards), NLB-1261 (from wild spiny mice) and NLB-1231 (from wild spiny mice).Item Effects of Metarhizium anisopliae on sand fly populations in their natural habitats in Marigat sub- County, Baringo County, Kenya(Centre for Biotechnology Research & Development,, 2010) Ngure, Peter K.; Ngumbi, Phillip M.; Kasili, Sichangi; Anjili, Christopher O.; Karanja, Robert M.; Kaburi, Josyline; Mwangi, Milkah; Kinuthia, Geoffrey; Kiarie, Martha; Nzau, Anastasia; Kepha, Stella; Maniania, Nguya K.; Irungu, LucyLeishmaniasis is one of the neglected tropical diseases that pose a threat to people in the endemic regions. In Africa, transmission is through the bite of an infected female phlebotomine sand fly. Disease control with chemotherapy is logistically difficult, toxic and expensive. Entomopathogenic fungi (EPF) hold great potential as alternative vector control for sandflies as demonstrated by their efficacy in recent laboratory experiments. The impressive results have merited testing of the effect of EPF on sand flies in their natural habitats. The goal of this study was to test the effect of EPF on sand fly populations on a small scale in a leishmania-endemic area in Kenya. Entomopathogenic fungi isolates were cultured on Sabourand dextrose agar (SDA) in Petri dishes and incubated at 22-280C. Conidia were produced on long white rice substrate and harvested by sifting the substrate through a 295 μm mesh size sieve and stored at 4- 2 6 0C before being used in the experiments. Metarhizium anisopliae isolates were selected for use in the field after showing 76.8 and 100% mortality in laboratory bred target insects. 2.0 x 1014 of dry conidia of the fungus were introduced into ten termite mounds through the shafts using a modified foot pump in Rabai, Marigat area of Baringo County, Kenya. The site harbours both Phlebotomus martini and P. duboscqi sandfly vectors. Sand fly densities, mycoses and survival after capture from the mounds were observed from week one post-treatment to week thirteen. Results indicate that the fungi in termite mounds caused three to ten-fold mortalities in the population of sand flies nine weeks after application. Longevity of sand flies collected from treated termite mounds was reduced to less than nine days after collection, whereas 90% of those from control mounds lived well over the nine days. Sand flies collected from the treated termite mounds during week nine had 100% mortality compared to 10.7% of those from the control mounds. Metarhizium anisopliae infection was observed in 42% of the sand fly cadavers collected from the treated termite mounds and 0% in the control group. The high susceptibility of sand flies to M. anisopliae suggests that fungi can be developed as potential vector control alternatives to synthetic chemical insecticides or preferentially be applied in integrated control strategies in order to gain maximum impact on adult sand fly populations. Further studies to determine the best methods for delivery and application in the diverse ecological settings of various leishmaniasis vectors are recommended.