Helminth composition and prevalence of indigenous and invasive synanthropic murid rodents in urban areas of Gauteng Province, South Africa

Abstract

Although synanthropic rodents such as the indigenous species, Mastomys coucha, and the invasive species, Rattus norvegicus, R. rattus and R. tanezumi, are well-known to be hosts to various micro- and macroparasites, their helminth parasite fauna is poorly studied in South Africa. In an attempt to remedy the situation, the aim of the present study was to investigate the helminth fauna of these sympatric rodent species, which were obtained from the informal settlements of Alexandra, Tembisa, Diepsloot and residential suburbs of Pretoria and Hammanskraal, Gauteng Province, South Africa. Helminths were recovered from the urinary bladder, liver and gastrointestinal tract and were identified morphologically and molecularly. The recovered nematodes were all rodent-specific and included Aspiculuris tetraptera, Eucoleus sp., Heterakis spumosa, Mastophorus muris, Nippostrongylus brasiliensis, Protospirura sp., Strongyloides ratti, Syphacia obvelata, Syphacia muris, Trichuris sp. and Trichosomoides crassicauda. Syphacia obvelata, a commensal nematode of laboratory rodents, was recovered from indigenous M. coucha. Strobilar stages of cestodes recovered included Hymenolepis diminuta, Hymenolepis nana and Inermicapsifer madagascariensis. Recovered metacestodes were strobilocerci of Hydatigera taeniaeformis from all three invasive Rattus species and coenurostrobilocerci of Hydatigera parva from M. coucha. An acanthocephalan, Moniliformis moniliformis, was recovered from R. rattus only. All rodent species examined showed high helminth infection prevalence (≥70%) with equal or higher nematode than cestode prevalence. Mastomys coucha, however, showed significantly lower cestode prevalence than Rattus species where they co-occur. Interspecific transmission of helminths likely occurs between invasive and indigenous rodents, and these rodents harbour several helminths that have zoonotic implications.

Molecular characterization of cosmopolitan and potentially co-invasive helminths of commensal, murid rodents in Gauteng Province, South Africa

“…2b) gene regions. The 18S phylogeny showed that the Nippostrongylus brasiliensis genotype recovered from R. norvegicus (Julius et al 2017) was nearly identical to the genotypes recovered from R. norvegicus in the UK and a Rattus sp. in Australia, however, despite several attempts in this study, the mtDNA counterpart for the COI gene region did not amplify and subsequent phylogeographic assessments could not be made.…”

“…Additionally, the Gauteng Province isolate of another pinworm, S. muris, was affiliated to a conspecific rat from Indonesia, which is part of the native range, and these geographical affiliations may represent co-invasion. The M. coucha associated S. obvelata was previously reported by Julius et al (2017) and may represent parasite spill over since S. obvelata was only previously recorded from laboratory rodents as a commensal endoparasite (Hussey 1957).…”

“…The mtDNA COI dataset for H. diminuta consisted of 791 bp fragments comprising 16 in-group taxa of which five were generated in a parallel study (Julius et al 2017) and 11 are reference sequences ( Table 2). The rRNA ITS dataset consisted of 711 bp fragments comprising eight taxa where five (two identical sequences not shown) were generated in this study (GenBank accession nos.…”

“…MG386201-07) and nine are reference sequences ( Table 2). The 18S dataset consisted of 16 in-group taxa of which seven were generated in a parallel study (Julius et al 2017), two in this study (GenBank accession nos. MG356472-3) and seven were reference sequences ( Table 2).…”

Rodents of Senegal and their role as intermediate hosts of Hydatigera spp. (Cestoda: Taeniidae)

“…Aside from the description of adult H. parva in a common genet (Genetta genetta) from South Africa (Baer, 1924) and in an African wildcat (Felis silvestris lybica) from the Democratic Republic of the Congo (Baer and Fain, 1965), polycephalic strobilocerci identified as H. parva have been described in Nile rats (Arvicanthis niloticus) from Sudan (Elowni and Abu Samra, 1988), in pygmy mice (Mus minutoides) from Nigeria (George et al 1990), in greater Egyptian gerbils (Gerbillus pyramidum) from Tunisia (Bernard, 1963), in southern multimammate mice (Mastomys coucha) from South Africa (Julius et al 2017), and in Guinea multimammate mice (Mastomys erythroleucus) from Sierra Leone and the Democratic Republic of the Congo (Southwell and Kirshner, 1937;Mahon, 1954). Larval stages of H. taeniaeformis have been observed in rats and other wild rodents from Egypt (Wanas et al 1993), Nigeria (Udonsi, 1989;Ivoke, 2009), South Africa (Julius et al 2017), and Sudan (Fagir and El-Rayah, 2009), whereas Nelson and Rausch (1963) observed Cysticercus fasciolaris Rudolphi, 1808 (i.e., C. fasciolaris is a historical synonym of H. taeniaeformis (Nakao et al (2013)) in the liver of black rats (Rattus rattus) in Kenya. Nevertheless, to our knowledge, the identity of Hydatigera isolates from the African continent has been molecularly confirmed only for specimens found in Rattus spp.…”