Centro de Biotecnologia - CB

A distribution model for Glossina brevipalpis and Glossina austeni in Southern Mozambique, Eswatini and South Africa for enhanced area-wide integrated pest management approaches

2024-08-29T11:26:58Z

A distribution model for Glossina brevipalpis and Glossina austeni in Southern Mozambique, Eswatini and South Africa for enhanced area-wide integrated pest management approaches Beer, Chantel J. de; Dicko, Ahmadou H.; Ntshangase, Jerome; Moyaba, Percy; Taioe, Moeti O.; Mulandane, Fernando C.; Neves, Luis; Mdluli, Sihle; Guerrini, Laure; Bouyer, Jérémy; Vreysen, Marc J. B.; Venter, Gert J. Glossina austeni and Glossina brevipalpis (Diptera: Glossinidae) are the sole cyclical vec- tors of African trypanosomes in South Africa, Eswatini and southern Mozambique. These populations represent the southernmost distribution of tsetse flies on the African continent. Accurate knowledge of infested areas is a prerequisite to develop and implement efficient and cost-effective control strategies, and distribution models may reduce large-scale, exten- sive entomological surveys that are time consuming and expensive. The objective was to develop a MaxEnt species distribution model and habitat suitability maps for the southern tsetse belt of South Africa, Eswatini and southern Mozambique.The present study used existing entomological survey data of G. austeni and G. brevipalpis to develop a MaxEnt species distribution model and habitat suitability maps. Distribution models and a checkerboard analysis indicated an overlapping presence of the two species and the most suitable habitat for both species were protected areas and the coastal strip in KwaZulu-Natal Province, South Africa and Maputo Province, Mozambique. The predicted presence extents, to a small degree, into communal farming areas adjacent to the protected areas and coastline, especially in the Matutuı́ne District of Mozambique. The quality of theMaxEnt model was assessed using an independent data set and indicated good perfor- mance with high predictive power (AUC > 0.80 for both species).The models indicated that cattle density, land surface temperature and protected areas, in relation with vegetation are the main factors contributing to the distribution of the two tsetse species in the area. Changes in the climate, agricultural practices and land-use have had a significant and rapid impact on tsetse abundance in the area. The model predicted low habi- tat suitability in the Gaza and Inhambane Provinces of Mozambique, i.e., the area north of the Matutuı́ne District. This might indicate that the southern tsetse population is isolated from the main tsetse belt in the north of Mozambique. The updated distribution models will be useful for planning tsetse and trypanosomosis interventions in the area.

Assessing the impact of rice cultivation and off-season period on dynamics of soil enzyme activities and bacterial communities in two agro-ecological regions of Mozambique

2024-08-29T09:52:35Z

Assessing the impact of rice cultivation and off-season period on dynamics of soil enzyme activities and bacterial communities in two agro-ecological regions of Mozambique Ezeokoli, Obinna T.; Nuaila, Valter N. A.; Obieze, Chinedu C.; Muetanene, Belo A.; Fraga, Irene; Tesinde, Maria Natalia; Ndayiragije, Alexis; Coutinho, João; Melo, Ana M. P.; Adeleke, Rasheed A.; Barros, Ana I. Ribeiro; Fangueiro, David Soil ecosystem perturbation due to agronomic practices can negatively impact soil pro- ductivity by altering the diversity and function of soil health determinants. Currently, the influence of rice cultivation and off-season periods on the dynamics of soil health determinants is unclear. Therefore, soil enzyme activities (EAs) and bacterial community compositions in rice-cultivated fields at postharvest (PH) and after a 5-month off-season period (5mR), and fallow-fields (5-years-fallow, 5YF; 10-years-fallow, 10YF and/or one-year-fallow, 1YF) were assessed in two agroecological regions of Mozambique. EAs were mostly higher in fallow fields than in PH, with significant (p < 0.05) differences detected for β-glucosidase and acid phosphatase activities. Only β-glucosidase activity was significantly (p < 0.05) different between PH and 5mR, suggesting that β-glucosidase is respon- sive in the short-term. Bacterial diversity was highest in rice-cultivated soil and correlated with NO 3 − , NH 4 + and electrical conductivity. Differentially abundant genera, such as Agromyces, Bacil- lus, Desulfuromonas, Gaiella, Lysobacter, Micromonospora, Norcadiodes, Rubrobacter, Solirubrobacter and Sphingomonas were mostly associated with fallow and 5mR fields, suggesting either negative effects of rice cultivation or the fallow period aided their recovery. Overall, rice cultivation and chemical parameters influenced certain EAs and shaped bacterial communities. Furthermore, the 5-month off-season period facilitates nutrient recovery and proliferation of plant-growth-promoting bacteria

Ticks and tick-borne pathogens infecting livestock and dogs in Tchicala-Tcholoanga, Huambo Province, Angola

2024-08-29T09:42:13Z

Ticks and tick-borne pathogens infecting livestock and dogs in Tchicala-Tcholoanga, Huambo Province, Angola Sili, Gourgélia; Byaruhanga, Charles; Horak, Ivan; Steyn, Helena; Chaisi, Mamohale; Oosthuizen, Marinda C.; Neves, Luís The diversity of ticks and tick-borne pathogens (TBPs) infesting domestic animals in Tchicala-Tcholoanga, Angola, in 2016 was investigated. Seventeen tick species were recorded, Amblyomma pomposum being the most abundant on cattle (40%), goats (38%) and sheep (35%); Rhipicephalus turanicus was the most abundant on dogs (46%). This study presents new records of Haemaphysalis paraleachi, R. compositus, R. kochi and R. sulcatus in Angola, the first georeferenced population of Ha. leachi in southern Africa and the second record of R. microplus in Angola. Using the reverse line blot (RLB) hybridisation assay, fifteen TBP species were detected in blood samples from cattle (n = 88), goats (n = 82), sheep (n = 85) and dogs (n = 85). F The most frequently detected species were Theileria velifera in cattle (78%), Theileria ovis in sheep (80%) and Babesia vogeli in dogs (35%). Species-specific quantitative PCR assays detected Babesia bigemina in 43% (35/80) of blood samples of cattle, while E. ruminantium was detected in 4% (3/70) of blood samples and in 7% of A. pomposum ticks. Anaplasma platys was detected from cattle (18%) and sheep (6%) during RLB analysis. These findings constitute pioneering research in Angola.

An atlas of tsetse and animal African trypanosomiasis in Zimbabwe

2024-08-29T09:32:54Z

An atlas of tsetse and animal African trypanosomiasis in Zimbabwe Shereni, William; Neves, Luis; Argilés, Rafael; Nyakupinda, Learnmore; Cecchi, Giuliano In the 1980s and 1990s, great strides were taken towards the elimination of tsetse and animal African trypanosomiasis (AAT) in Zimbabwe. However, advances in recent years have been limited. Previously freed areas have been at risk of reinvasion, and the disease in tsetse-infested areas remains a constraint to food security. As part of ongoing control activities, monitoring of tsetse and AAT is performed regularly in the main areas at risk. How- ever, a centralized digital archive is missing. To fill this gap, a spatially explicit, national-level database of tsetse and AAT (i.e. atlas) was established through systematic data collation, harmonization and geo-referencing for the period 2000–2019. Methods: The atlas covers an area of approximately 70,000 km 2 , located mostly in the at-risk areas in the north of the country. In the tsetse component, a total of 33,872 entomological records were assembled for 4894 distinct trap locations. For the AAT component, 82,051 samples (mainly dry blood smears from clinically suspicious animals) were collected at 280 diptanks and examined for trypanosomal infection by microscopy. Results: Glossina pallidipes (82.7% of the total catches) and Glossina morsitans morsitans (17.3%) were the two tsetse species recorded in the north and northwest parts of the country. No fly was captured in the northeast. The distribu- tion of AAT follows broadly that of tsetse, although sporadic AAT cases were also reported from the northeast, appar- ently because of transboundary animal movement. Three trypanosome species were reported, namely Trypanosoma brucei (61.7% of recorded infections), Trypanosoma congolense (28.1%) and Trypanosoma vivax (10.2%). The respective prevalences, as estimated in sentinel herds by random sampling, were 2.22, 0.43 and 0.30%, respectively. Discussion: The patterns of tsetse and AAT distributions in Zimbabwe are shaped by a combination of bioclimatic factors, historical events such as the rinderpest epizootic at the turn of the twentieth century and extensive and sustained tsetse control that is aimed at progressively eliminating tsetse and trypanosomiasis from the entire country. The comprehensive dataset assembled in the atlas will improve the spatial targeting of surveillance and control activi- ties. It will also represent a valuable tool for research, by enabling large-scale geo-spatial analyses