Virulence of &lt;i&gt;Trypanosoma congolense&lt;/i&gt; strains isolated from cattle and African buffaloes (&lt;i&gt;Syncerus caffer&lt;/i&gt;) in KwaZulu-Natal, South Africa

Motloang, Makhosazana; Masumu, Justin; Mans, Ben J.; Latif, Abdalla A.

doi:10.4102/ojvr.v81i1.679

Cited by 21 publications

(22 citation statements)

References 26 publications

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“…Early isoenzyme analyses revealed three genetic variants or subgroups within T. congolense (Majiwa, Hamers, Van Meirvenne, & Matthyssens, ; Young & Godfrey, ). The most virulent and widespread is the Savannah subgroup, which is found in the savannah ecosystem and leads to anaemia, weight loss and usually death within three months postinfection (Bengaly, Sidibe, Boly, Sawadogo, & Desquesnes, ; Bengaly, Sidibe, Ganaba et al., ; Motloang, Masumu, Mans, & Latif, ). The two other subgroups comprise the low‐ and nonpathogenic Forest and Kilifi T. congolense parasites, respectively (Bengaly, Sidibe, Boly et al., ; Bengaly, Sidibe, Ganaba et al., ).…”

Section: Introductionmentioning

confidence: 99%

Discovery and genomic analyses of hybridization between divergent lineages of Trypanosoma congolense, causative agent of Animal African Trypanosomiasis

et al. 2017

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Hybrid populations and introgressive hybridization remain poorly documented in pathogenic micro-organisms, as such that genetic exchange has been argued to play a minor role in their evolution. Recent work demonstrated the existence of hybrid microsatellite profiles in Trypanosoma congolense, a parasitic protozoan with detrimental effects on livestock productivity in sub-Saharan Africa. Here, we present the first population genomic study of T. congolense, revealing a remarkable number of single nucleotide polymorphisms (SNPs), small insertions/deletions (indels) and gene deletions among 56 parasite genomes from ten African countries. One group of parasites from Zambia was particularly diverse, displaying a substantial number of heterozygous SNP and indel sites compared to T. congolense parasites from the nine other sub-Saharan countries. Genomewide 5-kb phylogenetic analyses based on phased SNP data revealed that these parasites were the product of hybridization between phylogenetically distinct T. congolense lineages. Other parasites within the same region in Zambia presented a mosaic of haplotypic ancestry and genetic variability, indicating that hybrid parasites persisted and recombined beyond the initial hybridization event. Our observations challenge traditional views of trypanosome population biology and encourage future research on the role of hybridization in spreading genes for drug resistance, pathogenicity and virulence.

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Section: Introductionmentioning

confidence: 99%

Discovery and genomic analyses of hybridization between divergent lineages of Trypanosoma congolense, causative agent of Animal African Trypanosomiasis

et al. 2017

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“…In South Africa, Glossina brevipalpis Newstead and Glossina austeni Newstead are the vectors of Trypanosoma congolense and Trypanosoma vivax [4–7] that cause AAT in an area of about 16 000 km 2 in the north eastern parts of the KwaZulu-Natal Province [8,9]. Because of the limited options available for controlling the parasite, i.e.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of radiation sensitivity and mating performance of Glossina brevipalpis males

et al. 2017

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BackgroundArea-wide integrated pest management strategies that include a sterile insect technique component have been successfully used to eradicate tsetse fly populations in the past. To ensure the success of the sterile insect technique, the released males must be adequately sterile and be able to compete with their native counterparts in the wild.Methodology/Principal findingsIn the present study the radiation sensitivity of colonised Glossina brevipalpis Newstead (Diptera; Glossinidae) males, treated either as adults or pupae, was assessed. The mating performance of the irradiated G. brevipalpis males was assessed in walk-in field cages. Glossina brevipalpis adults and pupae were highly sensitive to irradiation, and a dose of 40 Gy and 80 Gy induced 93% and 99% sterility respectively in untreated females that mated with males irradiated as adults. When 37 to 41 day old pupae were exposed to a dose of 40 Gy, more than 97% sterility was induced in untreated females that mated with males derived from irradiated pupae. Males treated as adults with a dose up to 80 Gy were able to compete successfully with untreated fertile males for untreated females in walk-in field cages.Conclusions/SignificanceThe data emanating from this field cage study indicates that, sterile male flies derived from the colony of G. brevipalpis maintained at the Agricultural Research Council-Onderstepoort Veterinary Institute in South Africa are potential good candidates for a campaign that includes a sterile insect technique component. This would need to be confirmed by open field studies.

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“…We used mean survival time (MST) of mice post-infection as the main indicator of virulence as previously reported [23,30]; [24] and observed that the Tbr isolates were well distributed among the four virulence classes. This finding explains why clinical syndromes in HAT patients differ significantly even in a single HAT focus, thus complicating HAT diagnosis.…”

Section: Discussionmentioning

confidence: 99%

Differential virulence ofTrypanosoma brucei rhodesienseisolates does not influence the outcome of treatment with anti-trypanosomal drugs in the mouse model

Ndung’u

Murilla²,

Thuita

et al. 2020

Preprint

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18We assessed the virulence and anti-trypanosomal drug sensitivity patterns of Trypanosoma 19 brucei rhodesiense (Tbr) isolates in the Kenya Agricultural and Livestock Research 20 Organization-Biotechnology Research Institute (KALRO-BioRI) cryobank. Specifically, the 21 study focused on Tbr clones originally isolated from the western Kenya/eastern Uganda focus of 22 human African Trypanosomiasis (HAT). Twelve (12) Tbr clones were assessed for virulence 23 using groups(n=10) of Swiss White Mice monitored for 60 days post infection (dpi). Based on 24 survival time, four classes of virulence were identified: (a) very-acute: 0-15, (b) acute: 16-30, (c) 25 sub-acute: 31-45 and (d) chronic: 46-60 dpi. Other virulence biomarkers identified included: pre-26 patent period (pp), parasitaemia progression, packed cell volume (PCV) and body weight 2 27changes. The test Tbr clones together with KALRO-BioRi reference drug-resistant and drug 28 sensitive isolates were then tested for sensitivity to melarsoprol (mel B) pentamidine, diminazene 29 aceturate and suramin, using mice groups (n= 5) treated with single doses of each drug at 24 30 hours post infection. Our results showed that the clones were distributed among four classes of 31 virulence as follows: 3/12 (very-acute), 3/12 (acute), 2/12 (sub-acute) and 4/12 (chronic) isolates. 32 Differences in survivorship, parasitaemia progression and PCV were significant (P<0.001) and 33 correlated. The isolate considered to be drug resistant at KALRO-BioRI, KETRI 2538, was 34 confirmed to be resistant to melarsoprol, pentamidine and diminazene aceturate but it was not 35 resistant to suramin. At least 80% cure rates of all the test isolates was achieved with melarsoprol 36 (1mg/Kg and 20 mg/kg), pentamidine (5 and 20 mg/kg), diminazene aceturate (5 mg/kg) and 37 suramin (5 mg/kg) indicating that the isolates were not resistant to any of the drugs despite the 38 differences in virulence. This study provides evidence of variations in virulence of Tbr isolates 39 from a single HAT focus and confirms that these variations are not a significant determinant of 40 isolate sensitivity to anti-trypanosomal drugs. 41

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Virulence of <i>Trypanosoma congolense</i> strains isolated from cattle and African buffaloes (<i>Syncerus caffer</i>) in KwaZulu-Natal, South Africa

Cited by 21 publications

References 26 publications

Discovery and genomic analyses of hybridization between divergent lineages of Trypanosoma congolense, causative agent of Animal African Trypanosomiasis

Discovery and genomic analyses of hybridization between divergent lineages of Trypanosoma congolense, causative agent of Animal African Trypanosomiasis

Evaluation of radiation sensitivity and mating performance of Glossina brevipalpis males

Differential virulence ofTrypanosoma brucei rhodesienseisolates does not influence the outcome of treatment with anti-trypanosomal drugs in the mouse model

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