Browsing by Author "Keyyu, J. D."

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Isolation and potential for transmission of mycobacterium bovis at human–livestock–wildlife interface of the Serengeti Ecosystem, Northern Tanzania
(PubMed, 2015) Katale, B. Z.; Mbugi, E. V.; Siame, K. K.; Keyyu, J. D.; Kendall, S.; Kazwala, R. R.; Dockrell, H. M.; Fyumagwa, R. D.; Michel, A. L.; Rweyemamu, M; Streicher, E. M.; Warren, R. M.; Helden, P.; Matee, M. I.
Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is a multihost pathogen of public health and veterinary importance. We characterized the M. bovis isolated at the human– livestock–wildlife interface of the Serengeti ecosystem to determine the epidemiology and risk of crossspecies transmission between interacting hosts species. DNA was extracted from mycobacterial cultures obtained from sputum samples of 472 tuberculosis (TB) suspected patients and tissue samples from 606 livestock and wild animal species. M. bovis isolates were characterized using spoligotyping and Mycobacterial Interspersed Repetitive Units-Variable Tandem Repeats (MIRU-VNTR) on 24 loci. Only 5 M. bovis were isolated from the cultured samples. Spoligotyping results revealed that three M. bovis isolates from two buffaloes (Syncerus caffer) and 1 African civet (Civettictis civetta) belonged to SB0133 spoligotype. The two novel strains (AR1 and AR2) assigned as spoligotype SB2290 and SB2289, respectively, were identified from indigenous cattle (Bos indicus). No M. bovis was detected from patients with clinical signs consistent with TB. Of the 606 animal tissue specimens and sputa of 472 TBsuspected patients 43 (7.09%) and 12 (2.9%), respectively, yielded non-tuberculous mycobacteria (NTM), of which 20 isolates were M. intracellulare. No M. avium was identified. M. bovis isolates from wildlife had 45.2% and 96.8% spoligotype pattern agreement with AR1 and AR2 strains, respectively. This finding indicates that bTB infections in wild animals and cattle were epidemiologically related. Of the 24 MIRU-VNTR loci, QUB 11b showed the highest discrimination among the M. bovis strains. The novel strains obtained in this study have not been previously reported in the area, but no clear evidence for recent cross-species transmission of M. bovis was found between human, livestock and wild animals.
Isolation and Potential for Transmission of Mycobacterium bovis at Human–livestock–wildlife Interface of the Serengeti Ecosystem, Northern Tanzania
(DOI, 2017) Katale, B. Z.; Mbugi, E.; Siame, K. K.; Keyyu, J. D.; Kendall, S.; Kazwala, R. R.; Dockrell, H. M.; Fyumagwa, R. D.; Michel, A. L.; Rweyemamu, M.; Streicher, E. M.; Warren, R. M.; Helden, P.; Matee, M.
Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is a multihost pathogen of public health and veterinary importance. We characterized the M. bovis isolated at the human– livestock–wildlife interface of the Serengeti ecosystem to determine the epidemiology and risk of crossspecies transmission between interacting hosts species. DNA was extracted from mycobacterial cultures obtained from sputum samples of 472 tuberculosis (TB) suspected patients and tissue samples from 606 livestock and wild animal species. M. bovis isolates were characterized using spoligotyping and Mycobacterial Interspersed Repetitive Units-Variable Tandem Repeats (MIRU-VNTR) on 24 loci. Only 5 M. bovis were isolated from the cultured samples. Spoligotyping results revealed that three M. bovis isolates from two buffaloes (Syncerus caffer) and 1 African civet (Civettictis civetta) belonged to SB0133 spoligotype. The two novel strains (AR1 and AR2) assigned as spoligotype SB2290 and SB2289, respectively, were identified from indigenous cattle (Bos indicus). No M. bovis was detected from patients with clinical signs consistent with TB. Of the 606 animal tissue specimens and sputa of 472 TBsuspected patients 43 (7.09%) and 12 (2.9%), respectively, yielded non-tuberculous mycobacteria (NTM), of which 20 isolates were M. intracellulare. No M. avium was identified. M. bovis isolates from wildlife had 45.2% and 96.8% spoligotype pattern agreement with AR1 and AR2 strains, respectively. This finding indicates that bTB infections in wild animals and cattle were epidemiologically related. Of the 24 MIRU-VNTR loci, QUB 11b showed the highest discrimination among the M. bovis strains. The novel strains obtained in this study have not been previously reported in the area, but no clear evidence for recent cross-species transmission of M. bovis was found between human, livestock and wild animals.
Prevalence and risk factors for infection of bovine tuberculosis in indigenous cattle in the Serengeti ecosystem, Tanzania
(BMC Veterinary Research, 2013) Katale, B. Z.; Mbugi, E. V.; Karimuribo, E. D.; Keyyu, J. D.; Kendall, S.; Kibiki, G. S.; Godfrey-Faussett, P.; Michel, A. L.; Kazwala, R. R.; Helden, P.; Matee, M.
Background: Bovine tuberculosis (bTB) is a chronic debilitating disease and is a cause of morbidity and mortality in livestock, wildlife and humans. This study estimated the prevalence and risk factors associated with bovine tuberculosis transmission in indigenous cattle at the human-animal interface in the Serengeti ecosystem of Tanzania. Results: A total of 1,103 indigenous cattle from 32 herds were investigated for the presence of bTB using the Single Intradermal Comparative Tuberculin Test. Epidemiological data on herd structure, management and grazing system were also collected. The apparent individual animal prevalence of tuberculin reactors was 2.4% (95% confidence interval (CI), 1.7 – 3.5%), whereas the true prevalence was 0.6% CI, 0.6 – 0.7% as indicated by a reaction to avian tuberculin purified protein derivatives (PPD) which is more than 4 mm greater than the reaction to avian tuberculin PPD. The results showed that 10.6% (117/1,103) showed non-specific reactions (atypical mycobacterium). The herd prevalence of 50% (16/32) was found. Tuberculin skin test results were found to be significantly associated with age, location, size of the household and animal tested. Of 108 respondents, 70 (64.8%) individuals had not heard about bovine tuberculosis at all. Thirty five percent (38/108) of respondents at least were aware of bTB. About 60% (23/38) of respondents who were aware of bTB had some knowledge on how bTB is spread. Eighty one percent (87/108) of respondents were not aware of the presence of bTB in wildlife. There is regular contact between cattle and wild animals due to sharing of grazing land and water sources, with 99% (107/108) of households grazing cattle in communal pastures. Conclusion: The study has demonstrated a high reported interaction of livestock with wildlife and poor knowledge of most cattle owners concerning bTB and its transmission pathways among people, livestock and wildlife. Although the overall proportion of animals with bTB is relatively low, herd prevalence is 50% and prevalence within herds varied considerably. Thus there is a possibility of cross transmission of bTB at wildlife-livestock interface areas that necessitates use of genetic strain typing methods to characterize them accurately
Species diversity of non-tuberculous mycobacteria isolated from humans, livestock and wildlife in the Serengeti ecosystem, Tanzania
(BMC Infectious Diseases, 2014) Katale, B. Z.; Mbugi, E. V .; Botha, L.; Keyyu, J. D.; Kendall, S.; Dockrell, H. M.; Michel, A. L.; Kazwala, R. R.; Rweyemamu, M. M .; Helden, P. v.; Matee, M. I.
Background: Non-tuberculous mycobacteria (NTM), which are ubiquitous micro-organisms occurring in humans, animals and the environment, sometimes receive public health and veterinary attention as opportunistic disease-causing agents. In Tanzania, there is limited information regarding the diversity of NTM species, particularly at the human-livestock-wildlife interface such as the Serengeti ecosystem, where potential for cross species infection or transmission may exist. Methods: Mycobacterial DNA was extracted from cultured isolates obtained from sputum samples of 472 suspect TB patients and 606 tissues from wildlife species and indigenous cattle. Multiplex PCR was used to differentiate NTM from Mycobacterium tuberculosis complex (MTBC) members. NTM were further identified to species level by nucleotide sequencing of the 16S rRNA gene. Results: A total of fifty five (55) NTM isolates representing 16 mycobacterial species and 5 isolates belonging to the MTBC were detected. Overall, Mycobacterium intracellulare which was isolated from human, cattle and wildlife, was the most frequently isolated species (20 isolates, 36.4%) followed by M. lentiflavum (11 isolates, 20%), M. fortuitum (4 isolates, 7.3%) and M. chelonae-abscessus group (3 isolates, 5.5%). In terms of hosts, 36 isolates were from cattle and 12 from humans, the balance being found in various wildlife species. Conclusion:This study reveals a diversity of NTM species in the Serengeti ecosystem, some of which have potential for causing disease in animals and humans. The isolation of NTM from tuberculosis-like lesions in the absence of MTBC calls for further research to elucidate their actual role in causing disease. We are also suggesting a one health approach in identifying risk factors for and possible transmission mechanisms of the NTM in the agro-pastoral communities in the Serengeti ecosystem.
Species identification of Tanzanian antelopes using DNA barcoding
(Molecular Ecology Resources, 2011) Bitanyi, S.; Bjørnstad, G.; Ernest, E. M.; Nesje, M.; Kusiluka, L. J.; Keyyu, J. D.; Mdegela, R. H.; Røed, K. H.
Efficient tools for consistent species identification are important in wildlife conservation as it can provide information on the levels of species exploitation and assist in solving forensic-related problems. In this study, we evaluated the effectiveness of the mitochondrial cytochrome c oxidase subunit I (COI) barcode in species identification of Tanzanian antelope species. A 470 base-pair region of the COI gene was examined in 95 specimens representing 20 species of antelopes, buffalo and domestic Bovidae. All the Tanzanian species showed unique clades, and sequence divergence within species was <1%, whereas divergence between species ranged from 6.3% to 22%. Lowest interspecific divergence was noted within the Tragelaphus genus. Neighbour-joining phylogenetic analyses demonstrated that the examined COI region provided correct and highly supported species clustering using short fragments down to 100 base-pair lengths. This study demonstrates that even short COI fragments can efficiently identify antelope species, thus demonstrating its high potential for use in wildlife conservation activities.
Tuberculosis infection: occurrence and risk factors in presumptive tuberculosis patients of the Serengeti Ecosystem in Tanzania
(Research Gate, 2017) Mbugi, E.; Katale, B. Z.; Lupindu, A. M.; Keyyu, J. D.; Kendall, S. I.; Dockrell, H. M.; Michel, A.; D van Helden, P.
Background: Cross-species tuberculosis (TB) transmission between humans and animals has been reported for quite a long time in sub-Saharan Africa. Because humans and animals coexist in the same ecosystem, exploring their potential for cross-species transmission and the impact the disease may have on the health of humans, animals, and their products is critical. Objectives:This study aimed to identify risk factors for transmission of TB (Mycobacterium tuberculosis) and to assess the potential for zoonotic TB (Mycobacterium bovis) transmission in the Serengeti ecosystem where humans and animals are in intense contact. Our aim is to create a base for future implementation of appropriate control strategies to limit infection in both humans and animals. Methodology: We administered a semi-structured questionnaire to 421 self-reporting patients to gather information on risk factors and TB occurrence. In a parallel study, researchers screened sputum smears using Ziehl–Neelsen staining and confirmed by mycobacterial culture. We then performed descriptive statistics (Pearsons chi-square test) and logistic regression analysis to establish frequencies, association, and quantification of the risk factors associated with TB cases. Results: Our findings showed 44% (95% confidence interval [CI], 0.40-0.49) of the results were positive from sputum samples collected over a 1-year duration in areas with a high TB burden, particularly the Bunda district, followed by the Serengeti and Ngorongoro districts. Of the culture-positive patients who also had infections other than TB (43/187 patients), 21 (49%) were HIV positive. Contact with livestock products (odds ratio [OR] 6.0; 95% CI, 1.81-19.9), infrequent milk consumption (OR 2.5; 95% CI, 1.42-4.23), cigarette smoking (OR 2.9; 95% CI, 1.19-7.1.2), and alcohol consumption (OR 2.3; 95% CI, 1.22-4.23) were associated with a higher likelihood of TB infection. Conclusion: There was no evidence of direct cross-species transmission of either M tuberculosis or M bovis between humans and animals using the study methods. The absence of cross-species TB transmission could be due to limited chances of contact rather than an inability of cross-species disease transmission. In addition, not all people with presumptive TB are infected withTB, and therefore control strategies should emphasise confirming TB status before administering anti-TB drugs. Tuberculosis Infection: Occurrence and Risk Factors in Presumptive Tuberculosis.
Widespread Treponema pallidum Infection in Nonhuman Primates, Tanzania.
(centers for disease control and prevention., 2018) Chuma, I. S; Batamuzi, E. K.; Collins, D. A.; Fyumagwa, R. D.; Hallmaier-Wacker, L. K.; Kazwala, R. R.; Keyyu, J. D.; Lejora, I. A.; Lipende, I. F.; Lüert, S.; Paciência, F. M.D.; Piel, A.; Stewart, F. A.; Zinner, D.; Roos, C.; Knau, S.
We investigated Treponema pallidum infection in 8 nonhuman primate species (289 animals) in Tanzania during 2015–2017. We used a serologic treponemal test to detect antibodies against the bacterium. Infection was further confirmed from tissue samples of skin-ulcerated animals by 3 independent PCRs (polA, tp47, and TP_0619). Our findings indicate that T. pallidum infection is geographically widespread in Tanzania and occurs in several species (olive baboons, yellow baboons, vervet monkeys, and blue monkeys). We found the bacterium at 11 of 14 investigated geographic locations. Anogenital ulceration was the most common clinical manifestation; orofacial lesions also were observed. Molecular data show that nonhuman primates in Tanzania are most likely infected with T. pallidum subsp. pertenue–like strains, which could have implications for human yaws eradication.