Browsing by Author "Fyumagwa, R. D."

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Cyanobacterial toxins and bacterial infections are the possible causes of mass mortality of lesser flamingos in Soda lakes in northern Tanzania
(2013) Fyumagwa, R. D.; Bugwesa, Z; Mwita, M; Kihwele, E.S; Nyaki, A; Mdegela, R. H.; Mpanduji, D.G
During the mass die-off of lesser flamingos in Soda lakes of Tanzania in 2000, 2002 and 2004, clinicopathological and toxicological investigations were made in order to elucidate the likely cause of mortality. Water and tissue samples were collected from the lakes and from dead flamingos respectively. While water samples were analyzed for pesticide residues, tissues were analyzed for pesticide residues and cyanotoxins. The significant pathological lesions observed in fresh carcasses included oedema in lungs, enlarged liver, haemorrhages in liver with multiple necrotic foci, haemorrhages in kidneys and haemorrhages in intestines with erosion of mucosa. Analysis of cyanotoxins revealed presence of neurotoxin (anatoxin-a) and hepatotoxins (microcystins LR, RR). Concentrations of microcystins LR were significantly higher (P = 0.0003) in liver than in other tissues. Based on clinicopathological findings and concentrations of the detected cyanotoxins, it is suspected that cyanobacterial toxins concurrent with secondary bacterial infection were the likely cause of the observed mortalities in flamingos.
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.
Treponema pallidum Infection in the Wild Baboons of East Africa: Distribution and Genetic Characterization of the Strains Responsible
(PLOS ONE, 2012) Harper, K. N.; Fyumagwa, R. D.; Hoare, R.; Wambura, P. N.; Coppenhaver, D. H.; Sapolsky, R. M.; Alberts, S. C.; Tung, J.; Rogers, J.; Kilewo, M.; Batamuzi, E. K.; Leendertz, F. H.; Armelagos, G. J.; Knauf, S.
It has been known for decades that wild baboons are naturally infected with Treponema pallidum, the bacterium that causes the diseases syphilis (subsp. pallidum), yaws (subsp. pertenue), and bejel (subsp. endemicum) in humans. Recently, a form of T. pallidum infection associated with severe genital lesions has been described in wild baboons at Lake Manyara National Park in Tanzania. In this study, we investigated ten additional sites in Tanzania and Kenya using a combination of macroscopic observation and serology, in order to determine whether the infection was present in each area. In addition, we obtained genetic sequence data from six polymorphic regions using T. pallidum strains collected from baboons at two different Tanzanian sites. We report that lesions consistent with T. pallidum infection were present at four of the five Tanzanian sites examined, and serology was used to confirm treponemal infection at three of these. By contrast, no signs of treponemal infection were observed at the six Kenyan sites, and serology indicated T. pallidum was present at only one of them. A survey of sexually mature baboons at Lake Manyara National Park in 2006 carried out as part of this study indicated that roughly ten percent displayed T. pallidum-associated lesions severe enough to cause major structural damage to the genitalia. Finally, we found that T. pallidum strains from Lake Manyara National Park and Serengeti National Park were genetically distinct, and a phylogeny suggested that baboon strains may have diverged prior to the clade containing human strains. We conclude that T. pallidum infection associated with genital lesions appears to be common in the wild baboons of the regions studied in Tanzania. Further study is needed to elucidate the infection’s transmission mode, its associated morbidity and mortality, and the relationship between baboon and human strains.
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.