ABSTRACT
This study aimed at determining the identity of freshwater snails collected from selected water habitats frequented by wildlife as source of drinking water in the Matebeleland region of Zimbabwe and further screening the identified snails for natural infections with amphistomes using PCR. A total of 487 freshwater snails were collected from six areas in the Matebeleland region of Zimbabwe for identification and screening of amphistome infection. Eight freshwater snail species were morphologically identified and Biomphalaria pfeifferi, Bul. tropicus, Bul. truncatus, Bul. globosus, and L. (R.) natalensis were confirmed using the COI gene. Bulinus tropicus and Phy. acuta were the most abundant species at 33.9% (165/487) and 31.2% (155/487), respectively. DNA of amphistome was detected in 11.9% (58/487) of the collected snails. The highest infection rate was detected in Bul. globosus (44.4%). West Nicholson recorded the highest infection rate (33.9%), and infection was not detected in L. (R.) natalensis, Phy. acuta, and Bellamya spp. Amphistome DNA from M. tuberculata was successfully sequenced and identified as Calicophoron microbothrium. An additional band was detected in M. tuberculata, Bul. tropicus, and Bul. trancatus, which showed a 96.42% similarity to Paragonimus sp. sequence in the GenBank.
ABSTRACT
This review summarizes published records on the prevalence, species diversity, geographical distribution, mixed infections, co-infections with other trematodes and intermediate hosts (IHs) of amphistomes (rumen flukes) of wild ruminants in Africa. Literature search was conducted on Google Scholar, PubMed and JSTOR, using a combination of predetermined search terms and Boolean operators. Of the 54 African countries searched, results showed that occurrence of amphistome infections in wild ruminants have only been reported in 23 countries. A total of 38 amphistome species consisting of the following 11 genera were recorded, viz Bilatorchis, Calicophoron, Carmyerius, Choerecotyloides, Cotylophoron, Explanatum, Gastrothylax, Gigantocotyle, Leiperocotyle, Paramphistomum and Stephanopharynx. These were recorded in 39 wild ruminant species, belonging to the Bovidae family. The genus Carmyerius recorded the highest number of species (n = 13) across nine countries Africa. However, Calicophoron species (n = 9) were more widely distributed, occurring in 17 countries across all regions of Africa. Species of this genus collectively infected 27 wild ruminant species. However, at a species level, Cotylophoron cotylophorum infected the highest number of wild ruminant species. Prevalence of infection based on post-mortem examination ranged from 1.89% in African Buffalo to 100% in Defassa waterbuck from Egypt and Zambia, respectively. The most common mixed infections recorded were those between amphistomes of the same or different genus. Snail intermediate hosts (IHs) were described for 10/38 amphistome species, and these were predominantly species from Plarnobidae family. Despite the richness in diversity of amphistomes infecting wild ruminants in Africa, there is need to further confirm identity of snail IHs and the amphistome species using both morphological and molecular techniques. Furthermore, more studies are recommended to assess the burden of amphistomosis in commercially reared wildlife/game farming, mixed game and livestock farming systems in Africa.
ABSTRACT
BACKGROUND: Harvesting and consuming insects (entomophagy), particularly Imbrasia belina is widespread in developing countries like Zimbabwe. Due to their extraordinary nutritional content, tastiness, ease of processing and storage, Imbrasia belina has become a delicacy, reachable nutritious complement, and money source for some people in Zimbabwean communities. However, some harvesters and consumers have become allergic to the Imbrasia belina, popularly known as Mopani worms. This has been attributed or associated with the changes in the genetic structure of Imbrasia belina. Therefore, this research sought to compare the presence of the genes associated with allergic reactions to mopane worms from Gwanda and Umguza districts in Zimbabwe. METHODS: A lab-based observational study was conducted on collected Imbrasia belina samples from both districts. Fifteen samples of mopane worms were collected from each district, and DNA extraction was performed using DNeasy blood and tissue kit. The DNA extraction products were then amplified using a Polymerase chain reaction. The polymerase chain reaction products were run on agarose gel electrophoresis to determine the presence of the target genes. RESULTS: Three of the five samples from Gwanda district were positive for the tropomyosin gene, whereas two samples from Umguza district were positive. All the samples from the two districts were negative for arginine kinase genes. CONCLUSION: The study results highlighted that allergic reactions to Imbrasia belina reported in Gwanda district are associated with the presence of the tropomyosin gene, which has undergone polymorphism. Responsible authorities such as Gwanda local authority should develop bylaws that govern Imbrasia belina harvesting in the district.
