Browsing by Author "Mgode, G.F."

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African pouched rats for the detection of pulmonary tuberculosis in sputum samples
(2009) Weetjens, B.J; Mgode, G.F.; Machang’u, R.S; Kazwala, R; Mfi nanga, G; Lwilla, F; Cox, C; Jubitana, M; Kanyagha, H; Mtandu, R; Kahwa, A; Mwessongo, J; Makingi, G; Mfaume, S; Steenberge, J.V; Beyene, N.W; Billet, M; Verhagen, R
SETTING: Resource-limited settings in sub-Saharan African countries. OBJECTIVE: To utilise African giant pouched rats (Cricetomys gambianus) for the diagnosis of tuberculosis (TB) in human sputum. DESIGN: A specially designed cage with 10 sniffi ng holes and cassette-carrier was used. The sputum samples were put in the sample cassette, containing 10 samples in line, placed under matching sniffi ng holes. Rats were trained to sniff each consecutive sample, and indicate TB positives by fi xing their nose for 5 seconds at the sniffi ng hole. This behaviour was maintained by food reinforcement upon correct indications. A total of 3416 samples were used. RESULTS: Of the 20 trained rats, 18 were able to discriminate positive from negative sputum samples, with average daily sensitivities ranging from 72% to 100%, and average daily false-positives ranging from 0.7% to 8.1%. The use of multiple rats signifi cantly increased sensitivity and negative predictive value. CONCLUSION: Utilising trained sniffer rats for TB detection is a potentially faster screening method and is at least as sensitive as smear microscopy. This method could therefore be suitable for active case fi nding, especially where large numbers of samples are to be analysed in resource-limited settings, to complement existing diagnostic techniques.
Cladogenesis and endemism in Tanzanian mole-rats, genus Fukomys: (Rodentia: Bathyergidae): a role for tectonics?
(2010) Faulkes, C.G; Mgode, G.F.; Le Comber, S.C.; Bennett, N.C
African mole-rats of the family Bathyergidae are subterranean hystricomorph rodents found throughout sub- Saharan Africa, where the distributional ranges of the most speciose taxa are divided by the African Rift Valley. In particular, mole-rats of the genera Heliophobius and Fukomys are distributed widely, and their adaptive radiation appears to have been strongly influenced by the geological process of rifting. As a result, virtually all members of the genus Fukomys occur in locations west of the Rift Valley. However, a small number of isolated populations occur east of the Rift Valley in Tanzania, where Heliophobius is widespread and is the predominant bathyergid rodent. Phylogenetic analysis of mitochondrial cytochrome b sequences of previously unstudied Tanzanian mole-rats (genus Fukomys) and geographically adjacent populations strongly suggests that vicariance in the Western Rift Valley has subdivided populations of mole-rats and, together with climatic changes, played a role in the isolation of extralimital populations of Fukomys in Tanzania. Together with molecular clock-based estimates of divergence times, these results offer strong support for the hypothesis that the observed patterns of cladogenesis are consistent with tectonic activity in the ‘Mbeya triple junction’ and Rungwe volcanic province between Lakes Rukwa and Nyasa.
Comparative and functional morphology of the middle ear in Zambezian mole-rats (Coetomys – Cryptomys, Bathyergidae)
(Belg. J. Zool, 2005-12) Leirs, Herwig; Makundi, Rhodes H.; Davis, Stephen; Lange, Simone; Burda, Hynek; Assogbadjo, A.E.; Codjia, J.T.C.; Sinsin, B.; Ekue, M.R.M.; Mensah, G.A.; Mgode, G.F.; Mhamphi, G.A.; Katakweba, A. W.; Paemelaere, E; Willekens, N.; Leirs, H.; Machang’u, R.S.; Hartskeerl, R.A.
Within the family Bathyergidae, the genus Coetomys (Cryptomys) is the most speciose. However, an unambiguous morphological or morphometrical species diagnosis has not been feasible to date. The middle ear structures involved in sound transmission were examined and measured in six species of Zambezian mole-rats of varying body sizes : Coetomys amatus, C. anselli, C. darlingi, C. kafuensis, C. mechowi and C. whytei. Compari- sons revealed many differences in the shape of the middle ear ossicles allowing species differentiation. Bullar vol- ume, eardrum area and cross-sectional area of the bony meatus were positively correlated with body size (as repre- sented by condylo-basal length) whereas the size of middle ear ossicles was rather independent of body size. Middle ears shared typical features with those found in low-frequency hearing mammals. Contrary to the findings in heter- omyids and the Spalax ehrenbergi species complex, within the genus Coetomys, those species occupying more mesic habitats had more efficient tympano-ossicular systems (suggesting more sensitive hearing) than species from drier habitats.
Pcr detection of Leptospira DNA in rodents and insecti- vores from Tanzania
(Sokoine University of Agriculture, 2005-12) Mgode, G.F.; Mhamphi, G.; Katakweba, A.; Paemelaere, E.; Willekens, N.; Leirs, H.; Machang, R.S.; Hartskeerl, R.A.
The true prevalence of leptospirosis in Tanzania is unknown or underestimated. In this study we report on the prevalence of leptospirosis in Morogoro, Tanzania, by PCR detection of leptospiral DNA in 27 kid- neys of rodents (Mastomys spp, Rattus spp, and Mus spp) and insectivores (Crocidura spp). The PCR study comple- mented previous attempts to isolate the leptospires and to perform seroprevalence by the microscopic agglutination test (MAT). Results of this study indicated an overall detection rate of 11 % by PCR, 7.4% by isolation and 0% by the MAT. Based on our analysis, it is recommended to use PCR and isolation for the detection of leptospires in potential host animals.
Serological and molecular characterization of leptospira serovar Kenya from captive African giant pouched rats (Cricetomys gambianus) from Morogoro Tanzania
(2004-03-07) Machangu, R.S.; Mgode, G.F.; Assenga, J.; Mhamphi, G.; Weetjens, B.; Cox, C.; Verhagen, R.; Sondij, S; Goris, M.G.; Hartskeerl, R.A.
Two identical leptospiral isolates coded Sh9 and Sh25 obtained from the urine of captive African giant pouched rats (Cricetomys gambianus), destined for use as biodetector of antipersonnel landmines were typed as serovar Kenya using cross-agglutination absorption test and DNA fingerprinting with the insertion element sequences IS1533 and IS1500 derived primers. The two isolates were previously characterized using cultural and serological – microagglutination test as pathogenic leptospires of the serogroup Ballum, closely related to serovars Kenya and Peru. To our knowledge, this is the first reported in-depth characterization of leptospira isolates from Tanzania.