Parasites and Parasitic Diseases of Laboratory Animals in Plateau State Nigeria: The Zoonotic Implications

Parasitic infections in laboratory animals, are detrimental to the success of researches and can also infect personnel and researchers. This study is aimed at investigating the parasitic infections of laboratory animals maintained in animal houses of The National Veterinary Research Institute, Vom, Nigeria, as well determining the zoonotic implications of the parasites. Two hundred and six laboratory animals (55 guinea pigs, 72 rabbits, 29 rats and 50 mice) were sampled. Faecal samples and skin scrapings were collected and subjected to parasitological analyses. Pathological examinations were conducted on laboratory animals that had skin lesions. Sixteen different species comprising of 7 nematodes, 5 cestodes, 3 protozoans, and 1 mite were detected. Eimeria species (40/206; 19.42%; 95% CI = 14.44 – 25.25) was the most prevalent parasite, followed by Syphacia muris (26/206; 12.62%; 95% CI = 8.59 – 17.69). Entamoeba caviae, Tritrichomonas caviae, Rodentolepis microstoma, Rodentolepis nana, Heterakis spumosa, Capillaria hepatica and Cysticercus fasciolaris were the least prevalent with a 0.49% prevalence each. Three, four, five and six different species of parasites were detected in mice, guinea pigs, rats and rabbits respectively. The Chi square analysis revealed that the infection rate of parasites was significantly higher (p = <0.01) in mice compared to guinea pigs, rabbits and rats. Of the Sixteen species of parasites detected, Eimeria species, Syphacia muris, Rodentolepis diminuta, Rodentolepis microstoma, Rodentolepis nana, and Capillaria hepatica are zoonotic. This study showed that 40.29% of the studied laboratory animals were infected with one parasite species or the other. The outcome of this study stresses the zoonotic implications of the parasites detected. We thereby advise researchers and handlers to take caution and apply utmost sanitary measures in the handling of laboratory animals so as to prevent themselves from been infected with these zoonotic parasites.

Diversity, Prevalence and Risk Assessment of Nematode Parasites in Tatera indica found in Punjab State

Background: Present study was aimed to record diversity, prevalence and risk assessment of nematode parasites in Indian gerbil, Tatera indica, a wild rodent species found in crop fields. Methods: Total 180 Indian gerbils (T. indica) were live trapped from crop fields of Ludhiana, Punjab between April, 2019 to March, 2020 and examined for the diversity and prevalence of nematode parasites in liver and gastrointestinal tract. Result: Only 33 (18.33%) gerbils were found infected with four nematodes species i.e. Nippostrongylus brasiliensis (39.40%), Calodium hepaticum (21.21%), Trichuris muris (21.21%) and Syphacia muris (18.18%). Eggs of N. brasiliensis, T. muris and S. muris were found in faecal samples. Pale yellow lesions on surface of liver and subsequent histopathology of infected liver indicated the presence of C. hepaticum eggs entrapped in parenchyma. Host age (χ2 = 8.78, P = 0.03) and season (χ2 = 9.21, P = 0.01) significantly affected the prevalence of N. brassiliensis and C. hepaticum, respectively. Shannon-Weiner index and Species Evenness of nematode parasites were maximum in monsoon season (1.04 and 0.94, respectively). Based on results proper rodent pest management is advised by integrated control measures at village level to prevent spread of diseases caused by them.

Nematoda Parasit Pada Rattus spp. dari Pulau Simeulue, Aceh

Rattus spp. are often found living together in the human environment. Till date, there are no data on nematodes in rats from Simeulue Island. Therefore, a research on the nematodes of Rattus spp. from Simeulue Island, Aceh was conducted to know the species and the pattern of nematodes infection. The observation was carried out by dissecting 14 carcasses of Rattus spp. and then observing the internal organs for nematodes. For the result, we identified four species i.e., Syphacia muris, Cyclodontostomum purvisi, Gongylonema neoplasticum, and Nippostrongylus brasiliensis with prevalence 28.5%, 7.1%, 7.1%, 85.7%, respectively, and parasite indexes 1-23, 1, 1, 2-118 individual parasites in each host, respectively.Key words: nematodes, parasites, Rattus spp., Simeuleu Island.

Oxyurid nematodes of pet rodents in Slovakia - a neglected zoonotic threat

The role of rodents as reservoirs of helminths of public health importance is not well known. The zoonotic potential of Syphacia spp. has been confirmed; therefore, the study aimed to estimate the occurrence of oxyurid nematodes in small rodents from pet shops and breeding clubs in Slovakia. Fecal samples of 586 pet rodents kept in 133 cages were collected between 2016 and 2018 and examined by Faust´s flotation method. Four species of oxyurid nematodes, Syphacia muris, S. obvelata, Aspiculuris tetraptera and Paraspidodera uncinata were detected. A. tetraptera was found in the faecal samples of all rodent species included in this survey. The number of positive boxes varied from 5.4% in hamsters to 70.0% with mice. The prevalence of Syphacia muris was highest in Mongolian gerbils where up to 75.0% boxes were positive; S. obvelata was found in 26.7% of boxes with mice, 25.0% of boxes with Mongolian gerbils and 3.2% of boxes with rats. The high prevalence of Syphacia spp. in all animal species points out the infection risk for humans. Animals offered for sale are often in close contact with human beings; therefore they should be regularly tested for parasites and then effectively dewormed.

Antihelminic Activity of Carvacrol, Thymol, Cinnamaldehyde and P-Cymen Against the Free-Living Nematode Caenorhabditis elegans and Rat Pinworm Syphacia muris

In the present study we tested the dose andh time dependence of the antinematodal effects of carvacrol and tyhmol on Caenorabditis elegans, and the efficacy of carvacrol, thymol, p-cymene and cinnamaldehyde,which were administrated in the drinking water of rats naturally infected with the pinworm Syphacia muris. The control treatment of the infected rats was carried out with piperazine. Thymol caused a dose and time-dependent mortality in adult C. elegans. The value of the Median Lethal Concentration (LC50) of thymol was 117.9nM after 24h and 62.89 nM after 48h of exposure. Carvacrol exhibited a higher antinematodal efficiency than thymol. The LC50 of carvacrol, after 24 hours of exposure, was 53.03 nM, while after 48 hours it was 33.83 nM. On the other hand, piperazine showed an extremely high efficacy against S. muris infection in rats. Piperazine, at a dose of 625 mg/kg bw, administered in drinking water continuously for 10 days, eliminates the infection completely. However, none of the investigated active ingredients of essential oils were effective against S. muris. The reason for the lack of efficiency may be due to their pharmacokinetic properties. A relatively low amount of, orally administered, active ingredients of essential oils reaches the distal segments of the gastrointestinal tract, where S. muris inhabits the gut (colon and cecum). The obtained results, on C. elegans, indicate a clear dose and time-dependent antinematodal effect of thymol and carvacrol. However, for clinical application, it is necessary to examine the efficacy of microencapsulated formulations with a controlled release of active ingredients of essential oils in certain parts of the gastrointestinal tract.

Syphacia muris infection in rats attenuates colorectal carcinogenesis through oxidative stress and gene expression alterations. Implications for modulatory effects by Bryostatin-1

Accumulating evidence suggest that some infectious agents may interfere in the natural progression of neoplasia. This study examined the association between chronic infection with adult Syphacia muris parasites and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in rats. In addition, the conceivable therapeutic effect of Bryostatin-1, a potent extract of the marine Bryozoan, Bugulane ritina, was investigated against this combined effect.DMH administration has induced aberrant crypt foci (ACF), surrogate biomarkers for colorectal carcinogenesis, while the S. muris infection combined with DMH has significantly increased the total numbers of ACF. Nonetheless, treatment with Bryostatin-1 after infection has significantly reduced the ACF numbers particularly larger ones. This inhibition was concomitant with significant inhibition in the immunohistochemical levels of the ki67, Caspase-3 and IgM levels in colorectal epithelium, as well as serum levels of IgM and IgG. Additionally, treatment with Bryostatin-1 after S. muris + DMH has modulated enzymatic antioxidative markers levels of superoxide dismutase and catalase as well as the non-enzymatic antioxidant markers levels of reduced glutathione, lipid peroxidation, nitric oxide and total antioxidant capacity. Further, treatment with Bryostatin-1 has down-regulated the mRNA expression levels of COX-2 and APC genes in colorectal mucosa. In conclusion, infection with S. muris during colorectal carcinogenesis has significantly modulated the oxidative stress markers in the colorectum, while treatment with Bryostatin-1 has exerted significant curative potential. A mechanism could be explained that Bryostatin-1 treatment has reduced oxidative stress markers activities along with affecting host to parasite immunity possibly leading to changes in the COX-2 and APC expression, retarding cellular proliferation and subsequently reducing the colorectal carcinogenesis events.

High IL-1α production was induced in the WBN/Kob-Leprfa type 2 diabetes mellitus rat model and inhibited by Syphacia muris infection

Summary The novel WBN/Kob-Leprfa (fa/fa) congenic rat strain is considered a useful rat model of type 2 diabetes mellitus (T2DM). Accumulating findings suggest that low-grade inflammation is a causative factor in T2DM and that circulating levels of inflammatory cytokines are associated with insulin resistance. However, inflammatory cytokine profiles and their correlations with T2DM development/progression in fa/fa rats have not been studied. In this study, we found that the fa/fa rats had considerably high plasma levels of interleukin (IL)-1α. Abundant cecal IL-1α mRNA expression and cecal inflammation with infiltrating IL-1α-producing macrophages was observed in fa/fa rats. Bone marrow derived macrophages from fa/fa rats expressed high levels of IL-1α upon lipopolysaccharide stimulation. Furthermore, Syphacia muris infection, which delays the onset of T2DM, reduced both plasma and cecal IL-1α levels in fa/fa rats. These results suggest that macrophage infiltration and IL-1α secretion comprise an important part of T2DM development and that S. muris infection inhibits pro-inflammatory cytokine expression in fa/fa rats.

New host, geographical records, and factors affecting the prevalence of helminths infection from synanthropic rodents in Yucatán, Mexico

SummaryThe aim of this paper was to study the occurrence of helminths inMus musculusandRattus rattusfrom urban, suburban and rural settlements in Yucatán, Mexico; and to analyse the host factors (e.g. sex) related to helminths’ distribution. Helminths in a total of 279 rodents were surveyed by visual examination of the liver for metacestodes and faecal examination for helminth eggs using the formalin-ethyl acetate sedimentation technique. The cestodesHydatigera taeniaeformis(metacestodes detected in the liver) andHymenolepis diminuta,and the nematodesAspiculurissp.,Nippostrongylus brasiliensis,Syphacia muris,Syphacia obvelata, andTrichuris muriswere identified. InM. musculus, the prevalence of infection withT. murisandH. taeniaeformiswas higher in the rural village compared to those in the suburban neighbourhood. ForR. rattus, a higher prevalence of infection withH. diminutawas found in the urban site compared to that in the suburban site. This study reports the occurrence ofH. diminutaamong rodents living in close proximity to humans, representing a potential public health risk. In addition, this survey increases our understanding of dynamic transmission among intestinal helminths recorded in Yucatán, Mexico.