The prevalence and genomic characteristics of hepatitis E virus in murine rodents and house shrews from several regions in China

Background

Urban rodents and house shrews are closely correlated in terms of location with humans and can transmit many pathogens to them. Hepatitis E has been confirmed to be a zoonotic disease. However, the zoonotic potential of rat HEV is still unclear. The aim of this study was to determine the prevalence and genomic characteristics of hepatitis E virus (HEV) in rodents and house shrews.

Results

We collected a total of 788 animals from four provinces in China. From the 614 collected murine rodents, 20.19% of the liver tissue samples and 45.76% of the fecal samples were positive for HEV. From the 174 house shrews (Suncus murinus), 5.17% fecal samples and 0.57% liver tissue samples were positive for HEV. All of the HEV sequences obtained in this study belonged to Orthohepevirus C1. However, we observed a lower percentage of identity in the ORF3 region upon comparing the amino acid sequences between Rattus norvegicus and Rattus losea. HEV derived from house shrews shared a high percentage of identity with rat HEV. Notably, the first near full-length of the HEV genome from Rattus losea is described in our study, and we also report the first near full-length rat HEV genomes in Rattus norvegicus from China.

Conclusion

HEV is prevalent among the three common species of murine rodents (Rattus. norvegicus, Rattus. tanezumi, and Rattus. losea) in China. HEV sequences detected from house shrews were similar to rat HEV sequences. The high identity of HEV from murine rodents and house shrews suggested that HEV can spread among different animal species.

     

Zoonotic and non-zoonotic helminths in black rats of rain-fed and irrigated areas of Swat,Khyber Pakhtunkhwa,Pakistan

Present study was conducted to get information on helminth parasites of zoonotic importance among the black rats of district Swat, Pakistan. Two hundred and sixty nine rats were captured from agricultural ecosystem of the district using live captured traps from 2011 to 2013. Captured rats were anesthetized and surveyed for the presence of ectoparasites, then were carefully dissected for investigation of endoparsites. Helminth parasites of 8 species were identified. Presence of parasite was noticed in 23.7% of sampled rats. The infection rates of sampled rats was given in order of their infectivity as Syphacia obvelata 13(4.83%), Aspiculuris tetraptera 13(4.83%), Heterakis spumosa 12 (4.46%), Hymenolepis spp. 9(3.34%), H.diminuta 8(2.97%), Hymenolepis fusa 4(1.48%), Lutziella microacetabularae 4(1.48%) and Lutziella spp. 1 (0.37%). No significant difference (P < 0.4289) was found in prevalence of parasites among areas, crops, crop stages and sex of the host while adult rats were found more infected than sub-adults. S. obvelata and A. tetraptera were the most common species of helminths while Lutziella sp., 1 (0.37%) was found only in one host. Rattus rattus (the black rat) was regarded as the host of helminth parasites of zoonotic importance, therefore the hidden health hazards of this rodent species needed to be considered to prevent infectivity of humans. Current study was concluded that Rattus rattus harbored a wide variety of helminth parasites which shows a hidden risk to inhabitants of the region. Monitoring rats’ population in settle areas and educating the local community about the risk of rat borne parasitic diseases transmission through rats appears to be absolutely essential.     

Mitochondrial gene order change in Schistosoma (Platyhelminthes: Digenea: Schistosomatidae)

In the flatworm genus Schistosoma, species of which include parasites of biomedical and veterinary importance, mitochondrial gene order is radically different in some species. A PCR-based survey of 19 schistosomatid spp. established which of 14 Schistosoma spp. have the ancestral (plesiomorphic) or derived gene order condition. A phylogeny for Schistosoma was estimated and used to infer the origin of the gene order change which is present in all members of a clade containing Schistosoma incognitum and members of the traditionally recognised Schistosoma indicum, Schistosoma mansoni and Schistosoma haematobium spp. groups. Schistosoma turkestanicum, with the plesiomorphic gene order state, is sister to this clade. Common interval analysis suggests change in gene order, from ancestral to derived, consisted of two sequential transposition events: (a) nad1_nad3 to nad3_nad1 and (b) [atp6,nad2]_[nad3,nad1,cox1,rrnL,rrnS,cox2,nad6] to [nad3,nad1,cox1,rrnL,rrnS,cox2,nad6]_[atp6,nad2], where gene order of fragments within square brackets remain unchanged. Gene order change is rare in parasitic flatworms and is a robust synapomorphy for schistosome spp. that exhibit it. The schistosomatid phylogeny casts some doubt on the origin of Schistosoma (Asian or African), highlights the propensity for species to host switch amongst mammalian (definitive) hosts, and indicates the likely importance of snail (intermediate) hosts in determining and defining patterns of schistosome radiation and continental invasion. Mitogenomic sampling of Schistosoma dattai and Schistosoma harinasutai to determine gene order, and within key species, especially S. turkestanicum and S. incognitum, to determine ancestral ranges, may help discover the geographic origins of gene order change in the genus. Samples of S. incognitum from India and Thailand suggest this taxon may include cryptic species.     

Hematological and histopathological changes in Rattus norvegicus (Wistar) experimentally infected by Angiostrongylus cantonensis (Chen, 1935)

Eosinophilic meningitis caused by Angiostrongylus cantonensis is a zoonosis endemic to Southeast Asia and the Pacific islands. It is considered an emerging disease because it has been expanding both geographically and in terms of the range of hosts. In South America, the first cases were reported in Brazil and were attributed to eating infected snails. In this study, 70 adult females of Rattus norvegicus (Wistar) were used to evaluate hematology, blood gases, cardiac markers and lung histopathology changes caused by this parasite. Of them, 60 were individually infected by orogastric gavage with 100 L₃ larvae and 10 uninfected animals formed the control group. The results obtained demonstrate that infection caused by A. cantonensis in R. norvegicus promotes significant hematological changes induced in the vertebrate host, manifested mainly in the form of regenerative anemia, thrombocytopenia and eosinophilia. Additionally, histopathological changes in the lung parenchyma demonstrated in rodents reveal the occurrence of areas of necrosis and extensive fibrosis, being directly related to the development of cellular hypoxia and enzyme cardiac changes. This study can contribute to a better understanding of the relationship between A. cantonensis and R. norvegicus.     

Ecology of cutaneous leishmaniasis in Sinai: linking parasites,vectors and hosts

Cutaneous leishmaniasis (CL) is a neglected clinical form of public health importance that is quite prevalent in the northern and eastern parts of Egypt. A comprehensive study over seven years (January 2005-December 2011) was conducted to track CL transmission with respect to both sandfly vectors and animal reservoirs. The study identified six sandfly species collected from different districts in North Sinai: Phlebotomus papatasi, Phlebotomus kazeruni, Phlebotomus sergenti, Phlebotomus alexandri, Sergentomyia antennata and Sergentomyia clydei. Leishmania (-)-like flagellates were identified in 15 P. papatasi individuals (0.5% of 3,008 dissected females). Rodent populations were sampled in the same districts where sandflies were collected and eight species were identified: Rattus norvegicus (n = 39), Rattus rattus frugivorous (n = 13), Rattus rattus alexandrinus (n = 4), Gerbillus pyramidum floweri (n = 38), Gerbillus andersoni (n = 28), Mus musculus (n = 5), Meriones sacramenti (n = 22) and Meriones crassus (n = 10). Thirty-two rodents were found to be positive for Leishmania infection (20.12% of 159 examined rodents). Only Leishmania major was isolated and identified in 100% of the parasite samples. The diversity of both the vector and rodent populations was examined using diversity indices and clustering approaches.     

Verocytotoxin-Producing Escherichia coli in Wild Birds and Rodents in Close Proximity to Farms

Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission.     

Serological cross-reactivity between Strongyloides venezuelensis and Syphacia muris in Wistar rats (Rattus norvegicus)

One of the problems frequently faced in laboratory facilities is the possibility of the natural parasitic infection of lab animals, which can interfere with biomedical research results. The present study aimed to evaluate cross-reactivity among serum samples from Wistar rats (Rattus norvegicus) naturally infected with Syphacia muris and experimentally infected with Strongyloides venezuelensis. Forty rats were divided into four groups of ten animals each. Parasite load was evaluated by quantifying the adult worms from both helminthes species recovered from the intestines and the S. venezuelensis eggs eliminated in feces. Serological cross-reactivity by parasite-specific IgG detection was tested via enzyme linked immunosorbent assay (ELISA), immunofluorescence antibody test (IFAT) and immunoblotting. The results demonstrated that the quantity of S. venezuelensis eliminated eggs and parthenogenetic females decreased significantly in cases of co-infection with S. muris. ELISA revealed 100% cross-reactivity of serum samples from both species against the opposing antigen. IgG cross-reactivity was confirmed by IFAT using tissue sections of S. venezuelensis larvae and adult S. muris. Immunoblotting showed that IgG antibodies from the sera of animals infected with S. muris recognized eight antigenic bands from S. venezuelensis saline extract and that IgG antibodies from the sera of animals infected with S. venezuelensis recognized seven bands from S. muris saline extract. These results demonstrate the serological cross-reactivity between S. muris and S. venezuelensis in infected rats.     

Leptospira interrogans biofilm formation in Rattus norvegicus (Norway rats) natural reservoirs

Rattus norvegicus (Norway rat) is the main reservoir host of pathogenic Leptospira, the causative agent of leptospirosis, in urban environments. Pathogenic Leptospira forms biofilms in the environment, possibly contributing for bacterial survival and maintenance. Nonetheless, biofilms have not yet been studied in natural animal reservoirs presenting leptospiral renal carriage. Here, we described biofilm formation by pathogenic Leptospira inside the renal tubules of R. norvegicus naturally infected and captured in an urban slum endemic for leptospirosis. From the 65 rats carrying Leptospira in their kidneys, 24 (37%) presented biofilms inside the renal tubules. The intensity of leptospiral colonization in the renal tubules (OR: 1.00; 95% CI 1.05–1.1) and the type of occlusion pattern of the colonized renal tubules (OR: 3.46; 95% CI 1.20–9.98) were independently associated with the presence of Leptospira biofilm. Our data showed that Leptospira interrogans produce biofilms during renal chronic colonization in rat reservoirs, suggesting a possible role for leptospiral biofilms in the pathogenesis of leptospirosis and bacterial carriage in host reservoirs.     

Tissue specificities of Thelohania duorara,Agmasoma penaei, and Pleistophora sp., microsporidian parasites of pink shrimp, Penaeus duorarum

The pathology of pink shrimp, Penaeus duorarum, infected with the microsporidians Thelohania duorara, Agmasoma penaei, and Pleistophora sp. was described. Infections of T. duorara were widespread in most tissues; spores were located throughout the hemocoel, at the periphery of all striated muscle bundles, and in muscle and connective tissue surrounding the digestive tract. A. penaei infections invaded only dorsal abdominal muscles, muscles adjacent to blood vessels, and ovaries. Infected muscles and ovaries were eventually completely destroyed. Masses of A. penaei spores were often engulfed by hemocytes. Pleistophora sp. infected the interior of all striated muscles. Infected muscles were never completely destroyed but were often atrophied.     

Genome Sequence of Bartonella rattimassiliensis,a Bacterium Isolated from European Rattus norvegicus

Bartonella rattimassiliensis is a facultative intracellular bacterium isolated from the blood of Rattus norvegicus in Marseille. The present study reports the draft genome of B. rattimassiliensis strain 15908 (CIP 107705^T).     

Leptospirosis y rickettsiosis,reto diagnóstico para el síndrome febril en zonas endémicas

This is the case of a 50-year-old male from the region of Urabá, Colombia, with a mixed infection by Rickettsia rickettsii and Leptospira interrogans serovar Copenhageni ST78 and negative test for malaria and dengue fever.The patient presented with febrile syndrome and was unresponsive to systemic antibiotic treatment, who finally died in the intensive care unit. We established the postmortem diagnosis through molecular typification of the two etiological agents. In the inspection at the patient’s home, we found a Rattus rattus specimen infected with L. interrogans of the same serovar found in him. We found no ticks parasitizing the domestic animals cohabitating with the patient.This case of a mixed infection with progressive and fatal symptoms in a patient with occupational risk in a tropical disease endemic zone highlights the importance of considering the potential presentation of simultaneous etiologies in patients with multiple medical visits for unresolved febrile syndromes associated with risky exposure during agricultural activities.     

Focus: Zoonotic Disease: Prevalence and Diversity of the Streptobacillus Rat-bite Fever Agent,in Three Invasive,Commensal Rattus Species from South Africa

Rat-bite fever is an over-looked, global zoonotic disease that has a mortality rate of up to 13%, if untreated. Historically, this rat-borne disease has been attributed to one of two causative agents, Streptobacillus moniliformis or Spirillum minus. Given the confirmed presence of multiple invasive Rattus host species, high rat densities in urban, informal human settlements and increasing reports of rat bites in South Africa, we undertook a retrospective assessment of Streptobacillus in rats sampled from 16 urban sites, in Gauteng, the smallest but most populous Province in South Africa. Using a multi-gene PCR-sequencing approach, we confirmed Streptobacillus presence in 50.9% of oral swabs from three rat species and the presence of two Streptobacillus species, viz. S. moniliformis and S. notomytis. The two members of the cryptic Rattus rattus species complex (R. rattus and R. tanezumi), which are morphologically indistinguishable from each other, had markedly different colonization rates. Whereas 48.6% of rats from this species complex were Streptobacillus-positive, only 32.3% of Rattus tanezumi were positive compared to 61.5% R. rattus. Rattus norvegicus had an intermediate prevalence of 55.6%. Phylogenetic analysis of four gene regions (16S rRNA, gyrB, groEL, recA) identified two discrete lineages; S. moniliformis occurred exclusively in R. norvegicus, and S. notomytis was restricted to the two members of the R. rattus species complex; this represents the first report of Streptobacillus in R. tanezumi. These results highlight a largely overlooked zoonotic threat posed by invasive rats and confirm the presence of two discrete and potentially host-specific Streptobacillus lineages in South Africa.     

Rodent-Borne <Emphasis Type="Italic">Bartonella</Emphasis> Infection Varies According to Host Species Within and Among Cities

It is becoming increasingly likely that rodents will drive future disease epidemics with the continued expansion of cities worldwide. Though transmission risk is a growing concern, relatively little is known about pathogens carried by urban rats. Here, we assess whether the diversity and prevalence of Bartonella bacteria differ according to the (co)occurrence of rat hosts across New Orleans, LA (NO), where both Norway (Rattus norvegicus) and roof rats (Rattus rattus) are found, relative to New York City (NYC) which only harbors Norway rats. We detected human pathogenic Bartonella species in both NYC and New Orleans rodents. We found that Norway rats in New Orleans harbored a more diverse assemblage of Bartonella than Norway rats in NYC and that Norway rats harbored a more diverse and distinct assemblage of Bartonella compared to roof rats in New Orleans. Additionally, Norway rats were more likely to be infected with Bartonella than roof rats in New Orleans. Flea infestation appears to be an important predictor of Bartonella infection in Norway rats across both cities. These findings illustrate that pathogen infections can be heterogeneous in urban rodents and indicate that further study of host species interactions could clarify variation in spillover risk across cities.     

Subepidermal idioblasts and crystal macropattern in leaves of Ticodendron (Ticodendraceae)

Previously unknown leaf anatomy and foliar crystal macropattern are described for Ticodendron incognitum Gómez-Laurito and Gómez P. (monotypic eudicot family Ticodendraceae of a Fagales subclade with Betulaceae and Casuarinaceae). Leaf samples of five herbarium specimens were rehydrated, bleached, dehydrated to 100% ethanol, then xylol, mounted in Permount and viewed using polarizing microscopy. Large adaxial and abaxial hypodermal idioblasts occur. Numerous small druses populate palisade mesophyll, and fewer, larger druses populate the spongy mesophyll; this is the opposite of druse distribution in Fagaceae. Druses dominate major veins, many with visible cores, and some prisms occur. Minor veins exhibit isolated groups of 1–8 druses and rare prisms, but most terminal veins lack crystals. Many druses are misshapen or with epitactic crystals; several unusual variants of druses and prisms are common. Hypodermal idioblasts are an apomorphy for Ticodendraceae, but oil and resin cells occur in Myricaceae and Rhoipteleaceae of Fagales. Crystal forms and distribution differ from known Fagalean macropatterns.     

A microsporidium,Nosema pilicornis sp. n., of the purslane sawfly,Schizocerella pilicornis

A new microsporidian species, Nosema pilicornis, which infects the purslane sawfly, Schizocerella pilicornis, is described. This microsporidium infects most body tissues of the host. N. pilicornis was compared to other microsporidian species infecting Hymenoptera and to a group of similar microsporidia infecting Lepidoptera. N. pilicornis could be distinguished from all other microsporidian species on the basis of host range and ultrastructural characteristics of the spore. Spores were oval, containing 11 to 12 polar filament coils, and the polar filament had an angle of tilt of about 80°. N. pilicornis infected lepidopteran larvae, but only when heavy spore dosages were fed to early larval instars. S. pilicornis is a good but sporadic biological control agent of common purslane, Portulaca oleracea, a pernicious weed of vegetable, ornamental, and orchard crops. N. pilicornis, which is transovarially transmitted and causes high mortality in infected larvae, affects the performance of S. pilicornis as a biological control agent.     

GEOTROPIC ORIENTATION OF YOUNG RATS

The geotropic orientation of Rattus rattus (roof rat) obeys the equations previously found applicable for Rattus norvegicus. The former is more sensitive, geotiopically, and the numerical values of the constants in the equations for the two forms are found to differ significantly. Certain consequences of this difference are pointed out.     

The brachylaimidae (Trematoda: Digenea) of Australian native mammals and birds,including descriptions of Dasyurotrema n. g. and four new species of Brachylaima

The Brachylaimidae of Australian native animals are revised. Brachylaima dasyuri (Johnston, 1913) is redescribed from Dasyurus viverrinus, Phascogale tapoatafa and Isoodon macrourus. B. simile (Johnston, 1913) is removed from synonymy with B. dasyuri, reinstated as a valid species and redescribed from Perameles nasuta, Isoodon obesulus and Antechinus stuartii. B. antechini Peisley & Howell, 1975 is reduced to synonymy with B. simile. B. brindabellensis n. sp. is described from Rattus fuscipes. B. walterae n. sp. is described from Antechinus swainsonii and A. stuartii. B. delecta n. sp. is described from Antechinus flavipes. B. sandarsae n. sp. is described from Antechinus godmani. B. pulchellum (Johnston, 1917) is redescribed from Leucosarcia melanoleuca. An unnamed Brachylaima species is described from Isoodon macrourus. New host records are Brachylaima dasyuri from Phascogale tapoatafa and B. simile from Perameles nasuta. Dasyurotrema mascomai n. g., n. sp. is described from Antechinus swainsonii. The new genus is placed in the Panopistinae. It differs from the existing genera by having a single loop of the uterus passing anterior to the ventral sucker and the genital pore posterior to the posterior testis but still distinctly ventral. A second species of Dasyurotrema is recorded, but not described, from Antechinus stuartii. Brachylaimid metacercariae are described from Rhytida capillacea, Helicarion virens, H. mastersi and Vercularion strangei. In no case was a host species found to harbour more than one species from any brachylaimid genus at a single geographical site.     

Notes on the fleas Xenopsylla vexabilis Jordan, 1925 (Pulicidae: Siphonaptera) in Vietnam as related to the problem of anthropogenic plague foci

In the first half of the XX century, the flea Xenopsylla vexabilis, the main vector of the plague agent in the “natural plague foci” of the Hawaii, was shown to be a specific parasite of the small white-toothed rat Berylmys berdmorei, inhabiting the tropical forests and grasslands of Indochina, including Vietnam. X. vexabilis was not recorded in Vietnamese settlements. This flea was found in the fields bordering natural landscapes and agricultural areas as a parasite of the greater bandicoot rat Bandicota indica, Savile’s bandicoot rat B. savilei, and the rat Rattus koratensis. It was assumed that bandicoot rats may have played an important role in the introduction of the flea to the Pacific islands where X. vexabilis was then established on synanthropic rats. The new data do not support the concept of coevolution of the recent epizootic association Rattus exulans-Xenopsylla vexabilis-Yersinia pestis.     

Genetics of the ceramide/sphingosine-1-phosphate rheostat in blood pressure regulation and hypertension

Background

South Africa's long and extensive trade activity has ensured ample opportunities for exotic species introduction. Whereas the rich biodiversity of endemic southern African fauna has been the focus of many studies, invasive vertebrates are generally overlooked despite potential impacts on biodiversity, health and agriculture. Genetic monitoring of commensal rodents in South Africa which uncovered the presence of Rattus tanezumi, a South-East Asian endemic not previously known to occur in Africa, provided the impetus for expanded studies on all invasive Rattus species present.

Results

To this end, intensified sampling at 28 South African localities and at one site in Swaziland, identified 149 Rattus specimens. Cytochrome b gene sequencing revealed the presence of two R. tanezumi, seven Rattus rattus and five Rattus norvegicus haplotypes in south Africa. Phylogenetic results were consistent with a single, recent R. tanezumi introduction and indicated that R. norvegicus and R. rattus probably became established following at least two and three independent introductions, respectively. Intra- and inter-specific diversity was highest in informal human settlements, with all three species occurring at a single metropolitan township site. Rattus norvegicus and R. rattus each occurred sympatrically with Rattus tanezumi at one and five sites, respectively. Karyotyping of selected R. rattus and R. tanezumi individuals identified diploid numbers consistent with those reported previously for these cryptic species. Ordination of bioclimatic variables and MaxEnt ecological niche modelling confirmed that the bioclimatic niche occupied by R. tanezumi in south Africa was distinct from that occupied in its naturalised range in south-east Asia suggesting that factors other than climate may influence the distribution of this species.

Conclusions

This study has highlighted the value of genetic typing for detecting cryptic invasive species, providing historical insights into introductions and for directing future sampling. The apparent ease with which a cryptic species can become established signals the need for broader implementation of genetic monitoring programmes. In addition to providing baseline data and potentially identifying high-risk introduction routes, the predictive power of ecological niche modelling is enhanced when species records are genetically verified.     

Ecological,Social and Biological Risk Factors for Continued Trypanosoma cruzi Transmission by Triatoma dimidiata in Guatemala

Background

Chagas disease transmission by Triatoma dimidiata persists in Guatemala and elsewhere in Central America under undefined ecological, biological and social (eco-bio-social) conditions.

Methodology

Eco-bio-social risk factors associated with persistent domiciliary infestation were identified by a cross-sectional survey and qualitative participatory methods. Quantitative and qualitative data were generated regarding Trypanosoma cruzi reservoirs and triatomine hosts. Blood meal analysis and infection of insects, dogs and rodents were determined. Based on these data, multimodel inference was used to identify risk factors for domestic infestation with the greatest relative importance (>0.75).

Principal Findings

Blood meal analysis showed that 64% of 36 bugs fed on chickens, 50% on humans, 17% on dogs; 24% of 34 bugs fed on Rattus rattus and 21% on Mus musculus. Seroprevalence among 80 dogs was 37%. Eight (17%) of 46 M. musculus and three (43%) of seven R. rattus from households with infected triatomines were infected with T. cruzi Distinct Typing Unit I. Results from interviews and participatory meetings indicated that vector control personnel and some householders perceived chickens roosting and laying eggs in the house as bug infestation risk factors. House construction practices were seen as a risk factor for bug and rodent infestation, with rodents being perceived as a pest by study participants. Multimodel inference showed that house infestation risk factors of high relative importance are dog density, mouse presence, interior wall plaster condition, dirt floor, tile roofing and coffee tree presence.

Conclusions/Significance

Persistent house infestation is closely related to eco-bio-social factors that maintain productive T. dimidiata habitats associated with dogs, chickens and rodents. Triatomine, dog and rodent infections indicate active T. cruzi transmission. Integrated vector control methods should include actions that consider the role of peridomestic animals in transmission and community memberś level of knowledge, attitudes and practices associated with the disease and transmission process.