Genetic characterization of nodular worm infections in Asian Apes

Parasitic nematodes of Oesophagostomum spp., commonly known, as 'nodular worms' are emerging as the most widely distributed and prevalent zoonotic nematodes. Oesophagostomum infections are well documented in African non-human primates; however, the taxonomy, distribution and transmission of Oesophagostomum in Asian non-human primates are not adequately studied. To better understand which Oesophagostomum species infect Asian non-human primates and determine their phylogeny we analysed 55 faecal samples from 50 orangutan and 5 gibbon individuals from Borneo and Sumatra. Both microscopy and molecular results revealed that semi-wild animals had higher Oesophagostomum infection prevalence than free ranging animals. Based on sequence genotyping analysis targeting the Internal transcribed spacer 2 of rDNA, we report for the first time the presence of O. aculeatum in Sumatran apes. Population genetic analysis shows that there is significant genetic differentiation between Bornean and Sumatran O. aculeatum populations. Our results clearly reveal that O. aculeatum in free-ranging animals have a higher genetic variation than those in semi-wild animals, demonstrating that O. aculeatum is circulating naturally in wildlife and zoonotic transmission is possible. Further studies should be conducted to better understand the epidemiology and dynamics of Oesophagostomum transmission between humans, non-human primates and other wild species and livestock in Southeast Asia

First Study of <i>Ascaris lumbricoides</i> from the Semiwild Population of the Sumatran Orangutan <i>Pongo abelii</i> in the Context of Morphological Description and Molecular Phylogeny

There is little evidence that the already described and accepted taxa of ascarids (Ascaris lumbricoides, A. suum, and A. ovis) infecting individuals of taxonomically distant groups (hominids, pigs, sheep, goats, and dogs) can be genetically or morphologically distinguished. However, despite described morphological differences, e.g., due to intraspecific variation, these are insufficient for species determination and may indicate differences amongst ascarids because of cross infections, hybrid production, and specific adaptations to hosts. Herein, the results of a molecular and morphological analysis of ascarids parasitising Sumatran orangutans (Pongo abelii Lesson, 1827) in native populations are presented. The research took place in the Bukit Lawang area, Indonesia, in 2009. Throughout the year, fresh faecal samples were collected regularly from 24 orangutans, and all were examined for the presence of nematode adults. Only five adult worms from two orangutan females were found during regular collection. Using the integrative taxonomic approach, the nematodes found were identified as A. lumbricoides. The significance of the find and its rarity is documented by the fact that this is the first confirmed finding of adult ascarids from an original orangutan site (not from a zoo) in more than 130 years (including the long-term study spanning the last 20 years focusing on orangutan parasites and natural antiparasitic drugs). More accurate morphometric parameters and genetic differences for the identification of ascarids were established. These parameters will be helpful for other findings in great apes and will also be suitable for further and precise determination of this parasite. The details distinguishing between male and female specimens are also stated and well defined. A comprehensive evaluation of the situation of Ascaris species parasitising orangutans, including a comparison with previously described orangutan parasite (i.e., A. satyri—species inquirenda), is discussed

Prevalence of Cryptosporidium spp., Enterocytozoon bieneusi, Encephalitozoon spp. and Giardia intestinalis in Wild, Semi-Wild and Captive Orangutans (Pongo abelii and Pongo pygmaeus) on Sumatra and Borneo, Indonesia.

BACKGROUND:Orangutans are critically endangered primarily due to loss and fragmentation of their natural habitat. This could bring them into closer contact with humans and increase the risk of zoonotic pathogen transmission. AIMS:To describe the prevalence and diversity of Cryptosporidium spp., microsporidia and Giardia intestinalis in orangutans at seven sites on Sumatra and Kalimantan, and to evaluate the impact of orangutans' habituation and location on the occurrence of these zoonotic protists. RESULT:The overall prevalence of parasites in 298 examined animals was 11.1%. The most prevalent microsporidia was Encephalitozoon cuniculi genotype II, found in 21 animals (7.0%). Enterocytozoon bieneusi genotype D (n = 5) and novel genotype Pongo 2 were detected only in six individuals (2.0%). To the best of our knowledge, this is the first report of these parasites in orangutans. Eight animals were positive for Cryptosporidium spp. (2.7%), including C. parvum (n = 2) and C. muris (n = 6). Giardia intestinalis assemblage B, subtype MB6, was identified in a single individual. While no significant differences between the different human contact level groups (p = 0.479-0.670) or between the different islands (p = 0.992) were reported in case of E. bieneusi or E. cuniculi, Cryptosporidium spp. was significantly less frequently detected in wild individuals (p < 2×10-16) and was significantly more prevalent in orangutans on Kalimantan than on Sumatra (p < 2×10-16). CONCLUSION:Our results revealed that wild orangutans are significantly less frequently infected by Cryptosporidium spp. than captive and semi-wild animals. In addition, this parasite was more frequently detected at localities on Kalimantan. In contrast, we did not detect any significant difference in the prevalence of microsporidia between the studied groups of animals. The sources and transmission modes of infections were not determined, as this would require repeated sampling of individuals, examination of water sources, and sampling of humans and animals sharing the habitat with orangutans

Geographical distribution of <i>Pongo abelii</i> and <i>Pongo pygmaeus</i> on Sumatra and Kalimantan, respectively, with sampling areas highlighted.

<p>Geographical distribution of <i>Pongo abelii</i> and <i>Pongo pygmaeus</i> on Sumatra and Kalimantan, respectively, with sampling areas highlighted.</p

Maximum-likelihood tree of partial sequences of small ribosomal subunit (SSU) gene of <i>Cryptosporidium</i> spp. Sequences generated in this study are shaded.

<p>Taxa previously found in non-human primates are bolded. The tree with the highest log likelihood is shown. The percentage of trees in which the associated taxa clustered together is shown next to the branches. Only bootstrap values >50% are shown. Scale bar included in each tree.</p

Prevalence of <i>Cryptosporidium</i> spp., <i>Enterocytozoon bieneusi</i>, <i>Encephalitozoon</i> spp. and <i>Giardia intestinalis</i> in Wild, Semi-Wild and Captive Orangutans (<i>Pongo abelii</i> and <i>Pongo pygmaeus</i>) on Sumatra and Borneo, Indonesia

<div><p>Background</p><p>Orangutans are critically endangered primarily due to loss and fragmentation of their natural habitat. This could bring them into closer contact with humans and increase the risk of zoonotic pathogen transmission.</p><p>Aims</p><p>To describe the prevalence and diversity of <i>Cryptosporidium</i> spp., microsporidia and <i>Giardia intestinalis</i> in orangutans at seven sites on Sumatra and Kalimantan, and to evaluate the impact of orangutans’ habituation and location on the occurrence of these zoonotic protists.</p><p>Result</p><p>The overall prevalence of parasites in 298 examined animals was 11.1%. The most prevalent microsporidia was <i>Encephalitozoon cuniculi</i> genotype II, found in 21 animals (7.0%). <i>Enterocytozoon bieneusi</i> genotype D (n = 5) and novel genotype Pongo 2 were detected only in six individuals (2.0%). To the best of our knowledge, this is the first report of these parasites in orangutans. Eight animals were positive for <i>Cryptosporidium</i> spp. (2.7%), including <i>C</i>. <i>parvum</i> (n = 2) and <i>C</i>. <i>muris</i> (n = 6). <i>Giardia intestinalis</i> assemblage B, subtype MB6, was identified in a single individual. While no significant differences between the different human contact level groups (<i>p</i> = 0.479–0.670) or between the different islands (<i>p</i> = 0.992) were reported in case of <i>E</i>. <i>bieneusi</i> or <i>E</i>. <i>cuniculi</i>, <i>Cryptosporidium</i> spp. was significantly less frequently detected in wild individuals (<i>p</i> < 2×10⁻¹⁶) and was significantly more prevalent in orangutans on Kalimantan than on Sumatra (<i>p</i> < 2×10⁻¹⁶).</p><p>Conclusion</p><p>Our results revealed that wild orangutans are significantly less frequently infected by <i>Cryptosporidium</i> spp. than captive and semi-wild animals. In addition, this parasite was more frequently detected at localities on Kalimantan. In contrast, we did not detect any significant difference in the prevalence of microsporidia between the studied groups of animals. The sources and transmission modes of infections were not determined, as this would require repeated sampling of individuals, examination of water sources, and sampling of humans and animals sharing the habitat with orangutans.</p></div

Maximum-likelihood tree of whole ITS region of <i>Enterocytozoon bieneusi</i>.

<p>Sequences generated in this study are shaded. Taxa previously found in non-human primates are bolded. The tree with the highest log likelihood is shown. The percentage of trees in which the associated taxa clustered together is shown next to the branches. Only bootstrap values >50% are shown. Scale bar included in each tree.</p