Investigation of possible alternate animal reservoir hosts of Opisthorchis viverrini.

Chronic opisthorchiasis caused by Opisthorchis viverrini (O. viverrini) adversely affects human health and is associated with a fatal bile duct cancer (cholangiocarcinoma). Although cats and dogs are known animal reservoir hosts of opisthorchiasis, there is limited information about whether other fish-eating animals are fluke reservoirs. Wetlands along Chi River of Thailand have abundant intermediate host snails and fish for O. viverrini and diverse other animal species. This led to our investigation into whether other fish-eating animals can also become infected and be alternate reservoir hosts for human opisthorchiasis. Our preliminary study focused on the O. viverrini infection status of crab-eating or long-tailed macaques roaming in Kosumpi National Forest Park in Chi River Basin, Kosumpisai District of Mahasarakam Province, and rodents, small residential mammals and fish-eating birds living in Lawa wetland complex of Khon Kaen Province. Fecal samples of each animal were collected and modified formalin ether concentration technique was applied to identify infections. Additionally, participatory epidemiology was used to retrieve information from local communities on opisthorchiasis transmission in these animals. No O. viverrini infection was found in any fecal samples suggesting that monkeys, rodents, small residential mammals and birds in these two wetlands probably do not serve as alternate reservoir hosts of O. viverrini.

Vigilancia molecular de la malaria en potenciales reservorios silvestres que viven en una región históricamente endémica de Paraguay / Molecular surveillance of malaria in potential wild reservoirs that live in a historically endemic region of Paraguay

En Paraguay, no se han registrado casos autóctonos de malaria desde el 2011. Se realizó un estudio descriptivo observacional transversal en 6 monos y 23 aves que vivían en una región históricamente endémica de Paraguay para buscar presencia de reservorios silvestres de parásitos plasmodios causantes de la malaria. El ADN se extrajo por el método de Chelex a partir de una gota de sangre en un papel de filtro, y la detección del parásito se realizó mediante la PCR múltiple semianidada. Por este método, no se detectaron parásitos en ninguna de las 29 muestras. Se evaluó el riesgo potencial de circulación selvática de los parásitos que causan la malaria. Teniendo en cuenta la presencia de mosquitos anofelinos vectores en la zona, el hecho de que no se hayan observado casos positivos es un buen indicador teniendo en cuenta que nuestro país fue declarado recientemente como país libre de malaria por la OMS(AU)

In Paraguay, autochthonous cases of malaria have not been recorded since 2011. A cross-sectional observational descriptive study was conducted in 6 monkeys and 23 birds living in a historically endemic region of Paraguay to identify wild reservoirs of plasmodium parasites that cause malaria. DNA was extracted by the Chelex method from a blood drop in a filter paper, and parasite detection was performed by the seminested multiplex PCR. By this method, parasites were not detected in any of the 29 samples. The risk of potential sylvatic circulation of the parasites causing malaria was evaluated. Considering the presence of anopheline mosquitoes in the area, the fact that we did not find any positive cases is a good indicator as our country was recently certified as a malaria-free country by the WHO(AU)

Comparative study of three xenic media culture for cultivation of Balantidium coli strains / Estudo comparativo entre três meios de cultivo xênicos para o cultivo de cepas de Balantidium coli

Abstract The aim of the present study was to evaluate the growth rate of Balantidium coli in three xenic media cultures. Between 2013 and 2015, 10 B. coli isolates obtained from feces of Cynomolgus macaques, and 30 isolates from feces of pigs were studied. An inoculum of 500 trophozoites was transferred to tubes containing LES, TYSGM-9 and Pavlova media. These cultures were evaluated at incubation times of 24, 48, 72 and 96 hours. In most of strains analyzed wasn't showed significant difference in the growth rate comparing TYSGM-9 and Pavlova media (Wilcoxon p>0.016). In Pavlova medium, the trophozoites showed a maximum growth at 72 hours with significant difference when compared with the times of 24 h and 96 h (Wilcoxon <0.008). In LES, viable trophozoites were observed until 24 hours, with a significant difference (Friedman p<0.05, Wilcoxon p<0.016) in the number of parasite cells compared with Pavlova and TYSGM-9 media cultures. Thus, LES medium seemed to be less adequate than the other media for maintenance of B. coli. Despite the satisfactory results in TYSGM-9, Pavlova medium was considered ideal for the maintenance of this protozoan strain, guaranteeing the viability of the parasite with subculture every three days, presenting lower costs.

Resumo O objetivo do presente estudo foi avaliar a taxa de crescimento de Balantidium coli em três meios de cultura xênicos. Entre 2013 e 2015 foram estudados 10 isolados de B. coli obtidos de Cynomolgus macaques e 30 isolados de suínos. Um inóculo contendo 500 trofozoítos foi transferido para tubos contendo os meios LES, TYSGM-9 e Pavlova. Os cultivos foram avaliados com tempos de incubação de 24, 48, 72 e 96 horas. Na maioria das cepas analisadas não foi observado diferença significativa na taxa de crescimento comparando TYSGM-9 e Pavlova (Wilcoxon p>0,016). Em Pavlova, os trofozoítos apresentaram máximo de crescimento a 72 h com diferença significativa quando se comparou com os tempos de 24 h e 96 h (Wilcoxon <0,008). Em LES observou-se trofozoítos viáveis até 24 horas com diferença significativa (Friedman p<0,05 e Wilcoxon p<0,016), na quantidade de células parasitárias, quando comparado com Pavlova e TYSGM-9. Dessa forma, o meio LES mostrou-se ser menos adequado do que os outros, para a manutenção de B. coli. Apesar do resultado satisfatório em TYSGM-9, Pavlova foi considerado ideal para manutenção do protozoário, por garantir a viabilidade do parasito com subcultivos a cada três dias, além de apresentar menor custo.

Accelerated diversification of nonhuman primate malarias in Southeast Asia: adaptive radiation or geographic speciation?

Although parasitic organisms are found worldwide, the relative importance of host specificity and geographic isolation for parasite speciation has been explored in only a few systems. Here, we study Plasmodium parasites known to infect Asian nonhuman primates, a monophyletic group that includes the lineage leading to the human parasite Plasmodium vivax and several species used as laboratory models in malaria research. We analyze the available data together with new samples from three sympatric primate species from Borneo: The Bornean orangutan and the long-tailed and the pig-tailed macaques. We find several species of malaria parasites, including three putatively new species in this biodiversity hotspot. Among those newly discovered lineages, we report two sympatric parasites in orangutans. We find no differences in the sets of malaria species infecting each macaque species indicating that these species show no host specificity. Finally, phylogenetic analysis of these data suggests that the malaria parasites infecting Southeast Asian macaques and their relatives are speciating three to four times more rapidly than those with other mammalian hosts such as lemurs and African apes. We estimate that these events took place in approximately a 3-4-Ma period. Based on the genetic and phenotypic diversity of the macaque malarias, we hypothesize that the diversification of this group of parasites has been facilitated by the diversity, geographic distributions, and demographic histories of their primate hosts.

Human presence increases parasitic load in endangered lion-tailed macaques (Macaca silenus) in its fragmented rainforest habitats in Southern India.

BACKGROUND: Understanding changes in the host-parasite relationship due to habitat fragmentation is necessary for better management and conservation of endangered species in fragmented landscapes. Pathogens and parasites can pose severe threat to species in restricted environments such as forest fragments where there is increased contact of wildlife with human and livestock populations. Environmental stress and reduced nutritional level in forest fragments can influence parasite infection and intensity on the native species. In this study, we examine the impact of habitat fragmentation on the prevalence of gastrointestinal parasites in lion-tailed macaques in a fragmented rainforest in Western Ghats. METHODS: The prevalence of different gastrointestinal parasites was estimated from 91 fecal samples collected from 9 lion-tailed macaque groups in nine forest fragments. The parasites were identified up to genus level on the basis of the morphology and coloration of the egg, larva and cyst. The covariates included forest fragment area, group size and the presence/absence of human settlements and livestock in proximity. We used a linear regression model to identify the covariates that significantly influenced the prevalence of different parasite taxa. RESULTS: Nine gastrointestinal parasite taxa were detected in lion-tailed macaque groups. The groups near human settlements had greater prevalence and number of taxa, and these variables also had significant positive correlations with group size. We found that these parameters were also greater in groups near human settlements after controlling for group size. Livestock were present in all five fragments that had human settlements in proximity. CONCLUSION: The present study suggests that high prevalence and species richness of gastrointestinal parasites in lion-tailed macaque groups are directly related to habitat fragmentation, high anthropogenic activities and high host density. The parasite load partially explains the reason for the decline in immature survival and birth rate in small and isolated rainforest fragments in Anamalai Hills.

Echinococcus and Taenia spp. from captive mammals in the United Kingdom.

Taeniid tapeworms which include Echinococcus and Taenia spp. are obligatory parasites of mammals with pathogenicity usually related to the larval stages of the life cycle. Two species (or genotypes) of Echinococcus, E. granulosus sensu stricto and E. equinus, as well as several Taenia spp. are endemic in the UK. Here we report on the occurrence of larval cystic stages of Echinococcus and Taenia spp. in captive mammals in the UK. Using molecular techniques we have identified E. granulosus (G1 genotype) in a guenon monkey and a Philippine spotted deer; E. equinus in a zebra and a lemur; E. ortleppi in a Philippine spotted deer; E. multilocularis in a macaque monkey and Taenia polyacantha in jumping rats. To the best of our knowledge this is the first report of E. multilocularis in a captive primate translocated to the UK. As far as we know these are the first reports of E. equinus in a primate (lemur) and in a zebra; as well as E. granulosus (G1 genotype) and E. ortleppi in a cervid translocated to the UK. These infections and implications of the potential establishment of exotic species of cestodes are discussed.

[Identification of Taenia solium with abnormal number of scolex hooklets].

OBJECTIVE: To identify 3 suspected adults Taenia solium with abnormal number of hooklets on scolex collected from 3 patients of Dali in Yunnan Province. METHODS: Tapeworms were observed with unaided eyes. Morphology of the scolices and gravid proglottids was observed under microscope. DNA of gravid proglottids of the 3 adult tapeworms was extracted. T. solium mitochondrial cytochrome c oxidase subunit 1 gene (cox1) fragment and the full coxz1 gene were amplified by PCR. The cox1 gene of one isolate was sequenced. Eggs were hatched and oncospheres were inoculated into mice subcutaneously. Each mouse was subcutaneously injected with 1 mg dexamethasone once daily. Sixty days after infection, all mice were sacrificed and the morphology of cysticerci was observed. Two macaque monkeys were fed with eggs (2.5 x 10(5) per monkey). Euthanasia and autopsy were performed on day 47. Morphology of cysticerci were observed by light and scanning electron microscopy, and pathological changes of livers were observed. RESULTS: The number of hooklets on scolices of the three tapeworms was 0, 4 and 10, respectively, and lateral uterine branches in gravid proglottids were 7-12. PCR results of co1l gene fragment with species-specific primer for T. solium were all positive. The complete sequence of cox1 gene had 99.8% identity to the reported T. solium sequences. Cysticerci were obtained from hypoderm of mouse, muscles and hearts of monkey. Four suckers and 26-28 hooklets ranged in two rows around rostellum on scolex were microscopically observed. Milia-like lesions were found in monkey liver. Histological examination showed that there was fibrous connective tissue hyperplasia and eosinophil infiltration around lesion, and parasites were found in some cysts. CONCLUSION: The three tapeworms with abnormal number of hooklets have all been identified as T. solium. The larvae can infect macaque and lead to muscle and liver cysticercosis.

Significance of imaging features of alveolar echinococcosis in studies on nonhuman primates.

In this study, we report the imaging findings in two Japanese monkeys (Macaca fuscata) diagnosed with alveolar echinococcosis. Both monkeys were treated with albendazole for 10 years, without surgery. Radiography, computed tomography, and contrast-enhanced ultrasonography were performed under general anesthesia. This is the first report on contrast-enhanced ultrasonographic imaging for alveolar echinococcosis wherein perflubutane was used as the contrast medium. The findings of the imaging analyses were similar to those reported for alveolar echinococcosis in humans, such as snowflake sign and worm-eaten sign. In addition, the serology correlated well with the imaging data in these two monkeys. Therefore, we propose that the imaging findings of alveolar echinococcosis in nonhuman primates may be used to accumulate data on this condition in human alveolar echinococcosis.

Impact of infections and normal flora in nonhuman primates on drug development.

Preclinical safety studies that are required for the marketing approval of a pharmaceutical include single and repeat dose studies in rodent and nonrodent species. The use of nonhuman primates (NHPs), primarily macaques, as the nonrodent species has increased in recent years, in part due to the increase in development of biopharmaceuticals and immunomodulatory agents. Depending on the source of the macaques, they may vary in genetic background, normal flora, and/or the incidence of preexisting pathogens and inflammatory conditions. As the use of alternative sources of macaques rises to meet the increased demand for these animals in biomedical research, the toxicologic pathologist should be well versed in NHP pathology to adequately assess potential drug-related effects in the context of these variations. Such knowledge is particularly important in studies involving immunomodulatory drugs as the toxicologic pathologist should anticipate which type(s) of infections are most likely to arise depending on which arm of the immune system is modulated. The purpose of this review is to discuss the immunosuppressive (e.g., simian type D retrovirus, simian immunodeficiency virus) and opportunistic viruses (e.g., cytomegalovirus, adenovirus, simian virus 40, rhesus rhadinovirus, and lymphocryptovirus), primary and opportunistic bacteria (e.g., Campylobacter spp., Shigella flexneri, Yersinia enterocolitica, Moraxella catarrhalis, Mycobacterium avium complex, enteropathogenic Escherichia coli), and parasites (e.g., Plasmodium spp., Schistosoma spp., Strongyloides fulleborni) that have had the most profound impact on the interpretation of drug safety studies and/or that may reemerge as alternative sources of NHPs are used for drug safety studies.

Outbreak of larval Echinococcus multilocularis infection in Japanese monkey (Macaca fuscata) in a zoo, Hokkaido: western blotting patterns in the infected monkeys.

A high prevalence of larval Echinococcus multilocularis (Em) infection was found in zoo primates in Hokkaido, Japan. In October 1997, a Japanese monkey (Macaca fuscata) died and histopathologically diagnosed as alveolar hydatidosis. Serum samples were collected from the remaining Japanese monkeys and examined for antibodies against Em by enzyme-linked immunosorbent assay and western blotting. Serological tests showed 12 more animals of the remaining 57 monkeys were possibly infected. Ultrasonography revealed that nine of these 12 animals had a cystic lesion in the liver. The band patterns of western blotting in the monkeys were very similar to those in human.

Plasmodium coatneyi-infected erythrocytes bind to C32 amelanotic melanoma cells under static and flow conditions.

The ability of Plasmodium coatneyi-infected red blood cells (IRBCs) to bind to C32 amelanotic melanoma cells was examined under static and physiologic flow conditions in vitro. Six blood samples obtained from P. coatneyi-infected Japanese macaques (Macaca fuscata) with severe manifestations of disease were used in the static adhesion assay. All blood samples constantly exhibited binding of IRBCs to C32 cells under static conditions. Immunofluorescence staining with anti-CD36 mAb revealed a positive reaction at the surface of C32 cells with the infected erythrocytes, while the reaction with C32 cells without IRBCs was negative. To further examine the specificity of the interaction between P. coatneyi-infected erythrocytes and C32 cells, we carried out the binding assay under physiological flow conditions. In flow adhesion assay, three blood samples were used. Adhesion and rolling of IRBCs on C32 cells were detected at several rates of shear stress under flow conditions. At a shear stress of 1.0 dyne/cm(2), the number of IRBCs adherent to C32 cell averaged 5 to 6, and the number of IRBCs rolling on C32 cells averaged 6 to 11. The anti-CD36 mAb OKM5 inhibited 75-100% of IRBC adhesion and rolling, while the inhibitory effect of anti-ICAM-1 mAb 84H10 varied between 20-40%. The combination of anti-CD36 and anti-ICAM-1 mAb resulted in 83-100% inhibition of rolling and 100% inhibition of adhesion. These findings suggest that CD36 is one of the principal adhesion receptors of P. coatneyi-infected erythrocytes.

Ectopic locations of Taenia saginata asiatica cysticerci in the abdominal cavity of domestic pig and monkey.

Eleven Small-Ear-Miniature pigs, 1 Landrace Small-Ear-Miniature pig, and 1 monkey (Macaca cyclopis) were infected experimentally with eggs of Taenia saginata asiatica. They were found to harbor cysticerci on the liver surface, each with a thin, whitish fiber connecting to another location in the same lobe, or to other lobes of the liver; some were also connected individually to the diaphragm, abdominal muscles, and gall bladder with a short, thin fiber. Moreover, they also harbored extrahepatic cysticerci. Most of these were observed on the omentum and in the peritoneal cavity, except for some suspended individually in the abdominal cavity by a long, thin, whitish fiber. The origin of the extrahepatic cysticerci and whitish fibers is probably from the surface of the liver of the host.

Are asian monkeys the original mammalian hosts of Trypanosoma conorhini

Apresenta-se a hipótese de que os hospedeiros originais do Trypanosoma cororhini poderiam ser macacos asiáticos, porque a infecçäo natural destes tem sido achada, o vetor entre ratos é um Triatomíneo tropicopolita que pertence a um complexo de espécies asiáticas e os primatas têm-se mostrado mais suscetíveis ao parasito do que os ratos

Experimental infection of rhesus monkeys with Entamoeba histolytica mimics human infection.

Experimental infection of Entamoeba histolytica was successfully established in rhesus monkeys (Macaca mulatta). Parasites of proven pathogenicity maintained through liver passage in hamsters were used in this study. Laparotomized monkeys were inoculated intracecally/intrahepatically with trophozoites, or by oral administration of cysts (2000 cysts/ml). The cysts were isolated from an infected human stool sample. Formation of typical amebic lesions in the inoculated tissues along with alterations in hematologic indices were studied in the infected monkeys. All the experimentally inoculated monkeys showed leukocytosis and mild neutrophilia, while the hemoglobin content and levels of blood sugar and blood urea remained unaltered during the post-infection period. Specific antiamebic antibodies were readily detectable in post-infected sera.

A pathological study in cynomolgus monkeys infected with Edesonfilaria malayensis.

The host response to natural infection with Edesonfilaria malayensis in six female adult cynomolgus monkeys (Macaca fascicularis) imported from Indonesia was examined retrospectively by histopathology and clinical investigations. Reduced values of hemoglobin and hematocrit, an increased number of eosinophils, an elevated level of total protein and a decrease in A/G ratio were noted in hematological and blood chemical examinations of the infected animals. The filarial worms inhabited subserosal connective tissues of the abdominal and the thoracic cavities but not the lumina of the body cavities. There was thickening of the connective tissues, hemorrhage and adhesion of the serosa in the site occupied by the worms and the cysts. Histopathologically, proliferation of the connective tissues and/or granulation tissues, infiltration of eosinophils, lymphocytes and other cells associated with inflammation and hemorrhage were observed. The worms occasionally caused mechanical damage in nearby tissues such as the pancreas and the iliopsoas muscle. In addition, splenic nodules were found in five of the six infected monkeys as a secondary lesion specifically related to the infection with Edesonfilaria malayensis.