IS-24 Zoonotic Wildlife Parasites in Southeast Asia and Their Global Implications

Domestic animals and wildlife harbour a number of zoonotic pathogens of veterinary and public health concern. Approximately 75% of the emerging human infectious have a sylvatic cycle and wild animals are known to be efficient reservoirs of these infections. In addition, wild animals in the peri-urban setting act as efficient sources of infection for domestic animals including livestock. In Southeast Asia, the increasing destruction of natural habitats and the escalating trend in land use change has narrowed the disease transmission interface between humans, domestic animals and wildlife The complex interaction between the zoonotic pathogens, humans and animals, the arthropod vectors or intermediate hosts, and the environment, pose a serious challenge for the control and prevention of these zoonotic diseases. In many instances, this is confounded by the paucity of sound epidemiological data.In Southeast Asia, wild and domestic animals including livestock are hosts to a myriad of parasites of which a number are zoonotic. These pathogens may be transmitted to humans either through an invertebrate vector or intermediate hosts, or by ingestion of the infective stages. While these parasites are endemic to the region, they pose a serious threat to visitors and may have negative impacts to the tourism industry. Of pivotal concern are two protozoan parasites which cause zoonotic primate malaria (Plasmodium knowlesi), and human muscular and enteric sarcocystosis (Sarcocystis spp.). The major natural reservoir host for P. knowlesi are the Long-tailed Macaques (Macaca fascicularis) which is the most common and widespread species of non-human primate in Southeast Asia. This apicomplexan haemoparasites is efficiently transmitted from macaques to humans by Anopheles mosquitoes. Zoonotic primate malaria is now considered the most common and most deadly form of human malaria in many parts of Southeast Asia.Sarcocystosis is transmitted by ingestion of the Sarcocystis cystic tissue stages present in meat or oocysts in the environment. The life cycle of the parasite involves intermediate and definitive hosts of which humans may assume both roles with varying pathological consequences. While the disease may be self-limiting, muscular infections can cause considerable clinical signs in humans. Both these protozoan parasites have global implications as they are known to infect travellers visiting the region. As such, it is necessary that veterinarians and public health workers be aware of these potentially fatal zoonotic parasites of our local wildlife and domestic animals, in order to facilitate timely and accurate diagnosis, treatment and control measures.     

Descriptive Morphology, Morphometry, Community Structure and Spatial Distribution of Helminth Parasites in the Malayan Box Turtle, Cuora Amboinensis (Chelonia: Bataguridae) From Peninsular Malaysia

Thirty-six wild-caught Cuora amhoinensis from Peninsular Malaysia, comprising adults and juveniles of both sexes, were examined for helminth endoparasites. A total of 11 species (5 nematodes and 6 trematodes) were recovered from various organs, namely, Selpinema octorugatus (small intestine), Falcaustra duyagi (large intestine), Falcaustra sp. 1 (large intestine), Oxyurid larvae sp. 1 (liver), Oxyurid larvae sp. 2 (large intestine), Atractidae sp. (large intestine), Parorientodiscus magnus (large intestine), Digenea sp. 1 (liver), Digenea sp. 2 (large intestine), Polystomoides malayi (urinary bladder), and Polystomoides asiaticus (oral cavity). Seven of these helminths were not previously recorded in C. amboinensis, while 4 species, namely Falcaustra sp. 1, Digenea spp . 1 and 2., and the Atractidae sp. may be new species and geographical records, and require further taxonomic workout. The morphology and morphometry of 4 helminth species, namely, S. octorugatus, F. duyagi, P. magnus and P. malayi were studied in detail. A rigorous redescription of S. octorugatus was done with the aid of SEM and Pepsin-HCL digestion. New information was obtained including the number and arrangement of the buccal ridges, the absence of the lateral papillae, the addition of a fifth post anal papillae and the complex structure of the spicule tip. This study also demonstrated the usefulness of the relative positions of the caudal papillae and derived ratios, in the characterisation of the genus Selpinema. The helminth community structure of C. amboinensis in relation to age, gender and lifestage categories was investigated for the first time. This chelonian had a rich assemblage of helminths (observed richness = 11; expected richness, Cha02 = 9.17), with high diversity (Shannon's index = 0.78) and low evenness (0.36). This supports previous claims that C. amboinensis is vagile in food habits and habitat selection. Two helminths, namely S. octorugatus and F duyagi exhibited high intensity and prevalence, and were designated as core and dominant species, while Falcaustra sp. 1 and Oxyurid sp. 1 were regarded as unsuccessful pioneers. The helminth community structure between the various hosts age, gender and life stage categories were different, and may be attributed to disparate feeding habits and habitat utilisation. Results on the spatial distribution of the helminths found in the alimentary canal of C. amboinensis indicate that the worms are site specific, with a relatively narrow niche width. Further, interspecific competition may not be a prominent factor in determining the habitat restriction of helminths in this turtle host. Significant and positive correlation (Spearman' s rank coefficient = 0.45, P<0.05) was found between the intensity and prevalence of S. octorugatus and the packing density of the mucosal folds in the cranial duodenum. These helminths may actively select this niche, as the close proximity of the mucosal folds arranged in a complex labyrinth provide structural support and added traction, which function to stabilise the attachment interface. The large intestinal nematode (F duyagi), on the contrary, appeared to select its habitat based on physiological rather than morphological cues. It is likely that this luminal feeder is attracted to the prolonged retention of food material in the large intestine, and the presence of particulate digesta and abundant micro-organisms

Effects of olfactory enrichment on diurnal activity and stereotypic behaviour of captive Malayan tigers (Panthera tigris jacksoni)

Environment enrichment using olfactory stimuli is an emerging facet of zoo animal management, and has been shown to be effective in increasing behavioural diversity and reducing stereotypies in captive animals. This study was undertaken to document the effects of olfactory enrichment on the diurnal activity patterns and stereotypic repertoire in captive Malayan Tigers (Panthera tigris jacksoni). The diurnal behaviour of three pairs of adult P.t. jacksoni was observed at a local zoo using instantaneous scan sampling. The experimental protocol comprised three temporal blocks (pre-enrichment, enrichment and post-enrichment) lasting for five days each. A synthetically derived product (perfume) and a natural product (lime) were used as olfactory stimuli, and were applied on the walls of the enclosure following a fixed alternating routine. The frequency of behaviours and stereotypies observed for each tiger were scored following a defined ethogram. The diurnal activity budgets of the tigers were dominated by locomotion and stance (47%) and resting (33%). Pacing and patrolling were the major stereotypies exhibited by the tigers accounting for 8% of the diurnal activity budget. Investigative behaviour and scent marking significantly increased during the enrichment period. A reduction in locomotor activity was noted and the tigers spent more time resting in the presence of the olfactory stimuli. The frequency of stereotypic pacing and patrolling did not differ significantly between the pre-enrichment, enrichment and post-enrichment phases. However, the tigers did exhibit a trend of decreasing stereotypic behaviour pattern when the olfactory enrichment items were introduced. The highest contact frequency of the olfactory items was during the morning and evening. Olfactory stimuli have the potential to be used as a form of enrichment in captive tigers to increase their behavioural diversity and encourage investigative activities. Experimenting with varieties of olfactory stimuli may reveal preferences in captive tigers, and may prove effective in alleviating stress and reducing stereotypies in captive populations

Redescription of neopolystoma liewi Du Preez and Lim, 2000 (Monogenea: Polystomatidae) from Cuora amboinensis (Testudines: Geomydidae) with notes on specimen preparation.

Neopolystoma liewi Du Preez and Lim, 2000, is redescribed on the basis of specimens collected from the type host, Cuora amboinensis, in Malaysia during 2008. Morphometric comparison of the new specimens with the original description revealed significant differences because of differences in specimen preparation. The current material was killed in hot formalin without coverglass pressure, whereas the specimens from the original description were killed and fixed with coverglass pressure. Coverglass pressure resulted in increases of 30%–70% in most measurements of body organs. Sclerotized structures (genital and haptoral hooks and eggs) or structur es with sclerotized supports (haptoral suckers) were not affected by coverglass pressure. The coefficient of variation of measurements from worms killed with hot formalin was low (,10%) for most structures. The authors recommend discontinuing the use of flattening in the preparation of monogenetic trematodes, with the exception of a small number of specimens necessary to accurately view structures not easily seen in unflattened material. Measurements from flattened specimens should not be used in species descriptions

Assemblages of ectoparasites and haemoparasites in the Gallus gallus complex in Selangor, Malaysia.

Parasites are known to be host-specific through adaptive radiation and tandem evolution with their hosts. However, selective pressures like rapid environmental changes and the adaptation of the hosts to novel habitats often influence the assemblages of parasites. This research investigates the ectoparasite and haemoparasite fauna on the Gallus gallus complex in Selangor, with reference to two groups, namely, the wild Red Jungle fowl which is believed to be the ancestor of all the domestic chickens, and the indigenous free-ranging village chickens. Fifteen adult Red Jungle fowls (9 females and 6 males) and 15 indigenous village chickens (8 females and 7 males) were examined to determine the ectoparasite and haemoprotozoan assemblage among the Gallus gallus complex in Selangor. Blood was collected via venipuncture for detection of intra- and inter-erythrocyte haemoparasite. Five feathers from various parts of the body, namely, the primary wing, tail, axilla, thigh, neck, back and breast were plucked from each bird for examination of ectoparasites. Four species of blood parasites were found including microfilaria, Trypanosoma, Plasmodium and Leucocytozoon sabrazesi. The Red Jungle fowl and village chickens did not share the same kind of blood parasites apart from microfilaria. Six species of ectoparasites were detected, namely, Lipeurus caponis, Menopon gallinae, Gonoides dissimilis, Megninia cubitalis, Goniocotes sp. and Haemaphysalis sp. The species composition of ectoparasites was found to be similar between the Red Jungle fowl and village chickens. However, the prevalence and intensity of infection was higher in the Red Jungle fowl. There appears to be subtle microhabitat segregation between the species of ectoparasites. The Lipeurus caponis are distributed throughout the body in both the Red Jungle fowl and village chickens, indicating that they are not selective. Menopon gallinae and Gonoides dissimilis selected the shorter feathers on the neck, thigh, axilla, back and breast, which is closer to host body. Megninia cubitalis preferred the wing and tail feathers. The Red Jungle fowl harbors more ectoparasite and haemoparasite at a higher infestation rate compared to village chickens. This may be due to the differences in habitat, behaviour and diet, and warrants further investigation

First case of pulmonary acariasis in a pig-tailed macaque in Malaysia

A 15 year-old male, southern pig-tailed macaque (Macaca nemestrina), was found to have a history of bloody urine, inappetance, weight loss, and was weak before death. Multiple yellow to gray nodular-like lesions were observed grossly all over the lung. Some of the nodules were flattened and some were raised and there were also cavitations and tubercles-like lesions on the cut surface. Histopathologically, focal granulomatous lesions were seen throughout the lungs, especially those with the presence of mites. There were moderate alveolar macrophages observed with mild eosinophilic, plasma cells, and slight lymphocytes and neutrophilic cells infiltration. There was also the presence of the brownish mite pigments in the lung tissue as well as in macrophages. Diagnosis was made from the morphological observation of intact mites isolated from lung tissues. This is the first report on pulmonary acariasis in Malaysia

SHP2 phosphatase promotes mast cell chemotaxis toward stem cell factor via enhancing activation of the Lyn/Vav/Rac signaling axis

SHP2 protein-tyrosine phosphatase (encoded by Ptpn11) positively regulates KIT (CD117) signaling in mast cells and is required for mast cell survival and homeostasis in mice. In this study, we uncover a role of SHP2 in promoting chemotaxis of mast cells toward stem cell factor (SCF), the ligand for KIT receptor. Using an inducible SHP2 knockout (KO) bone marrow-derived mast cell (BMMC) model, we observed defects in SCF-induced cell spreading, polarization, and chemotaxis. To address the mechanisms involved, we tested whether SHP2 promotes activation of Lyn kinase that was previously shown to promote mast cell chemotaxis. In SHP2 KO BMMCs, SCF-induced phosphorylation of the inhibitory C-terminal residue (pY507) was elevated compared with control cells, and phosphorylation of activation loop (pY396) was diminished. Because Lyn also was detected by substrate trapping assays, these results are consistent with SHP2 activating Lyn directly by dephosphorylation of pY507. Further analyses revealed a SHP2- and Lyn-dependent pathway leading to phosphorylation of Vav1, Rac activation, and F-actin polymerization in SCF-treated BMMCs. Treatment of BMMCs with a SHP2 inhibitor also led to impaired chemotaxis, consistent with SHP2 promoting SCF-induced chemotaxis of mast cells via a phosphatase-dependent mechanism. Thus, SHP2 inhibitors may be useful to limit SCF/KIT-induced mast cell recruitment to inflamed tissues or the tumor microenvironment

Common species of Cyclorraphan Diptera in a Red Junglefowl Farm, Selangor, Malaysia

A study on the prevalence of Cyclorrhaphan Diptera species was carried out in a Red Jungle Fowl Farm, Dengkil, Selangor, Malaysia. Trappings were done twice a day, in the morning and evening, using hand nets and baited traps over a duration of 7 days. Chicken intestines were used as bait to attract the flies. The mean temperature and relative humidity during the period of sample collection were recorded. The flies were counted and the identification of species was based on standard taxonomic keys. Eleven species of flies were detected on the farm, representing eight genera; Chrysomya megacephala, Chrysomya rufifacies, Lucilia cuprina, Hemipyrellia liqurriens, Musca domestica, Musca sorbens, Musca ventrosa, Parasacrophaga, Boettcherisca, Seniorwhitea princeps and Chrysomela cf. aenea. The most prevalent fly species was Chrysomya megacephala, accounting for 80% of the total catch, followed by Musca domestica (5.15%). The other species were present in less than 5% of the catch. There was no significant correlation between temperature and the active fly population (r=-0.324, n=14, p=0.258). Similarly, the relative humidity did not have a significant effect on the number of flies on the farm (r=0.257, n=14, p=0.376). The number of female flies on the farm was high, comprising 64.42% of the total fly population. Certain species of flies displayed temporal activity. Chrysomyza cf. aenea and Seniorwhitea princeps were active in the morning, while Boetcherisca sp. was only encountered in the evening. The correct identification of the fly species, and knowledge on their temporal distribution and sex ratios, are important in order to ensure that control measures can be carried out in a more effective manner

Prevalence of endoparasites in village chicken (Gallus gallus domesticus) and wild jungle fowl (Gallus gallus spadiceus).

Thirty apparently healthy chickens comprising 15 adult wild jungle fowl (Gallus gallus spadiceus) and 15 free-ranged village chickens (Gallus gallus domesticus) were obtained from Jenderam Hulu in the district of Sepang, Selangor, Malaysia. From these samples, 3 of the village chickens were kept in a closed house system whereas the other village chickens were free ranged. All the wild red jungle fowls were caught from the Jinjarum in the district of Banting, Selangor. The nematodes species recovered from the necropsied 15 wild jungle fowls were Oxyspirura manson (32.6%) with mean intensity of 13.7 and Lemdana sp.(1.5%) with mean intensity of 3. Capillaria sp (0.5%) with mean intensity of 1.5. Tetrameres sp.(4.8%) with mean intensity of 6.5 and Heterakis gallinarum (10.85%) with mean intensity of 4.6. The cestodes recovered were Raillietina sp.(20.4%) with mean intensity of 11.1 and Hyemenolepis sp. (1.84%) with mean intensity of 1.03. Tanaisia sp.(26.5%) is the trematodes recovered with mean intensity of 26.5 and there is also the presence of Acanthocephala sp.(1.5%) with mean intensity of 2.25 in this group of chicken. In 15 village chicken, nematodes found were Oxyspirura mansoni (55.7%) mean intensity of 3.5, Lendana sp. (1.47%) with mean intensity of 31.3. Syngamus trachea (0.9%) with mean intensity of 2.5, Capillaria sp (0.7%) mean intensity of 1, Tetrameres sp. (4.8) mean intensity of 8.7, Ascaridia sp.(2.6%) mean intensity of 3.5 and Heterakis gallinarum (15.6%) with mean intensity of 8.5. The cestodes that were recovered were only Raillietina sp. (15.3%) with mean intensity of 8.7 and the trematodes were Tanaisia sp.(1.8%) with mean intensity of 10. From the results obtained, there was no significant difference in the endoparasites seen in village chicken and wild jungle fowl based on the T-test (P>0.05). The most common parasites in these two groups of chickens were the nematodes species Heterakis gallinarum

An updated checklist of the herpetofauna of the Belum-Temengor forest reserves, Hulu Perak, Peninsular Malaysia

A herpetofaunal survey was carried out in Temengor Forest Reserve, Peninsular Malaysia during the second Temengor Scientific Expedition conducted from 1st to 10th October 2012. This study represents the first records of amphibians and reptiles of Sungai Enam Basin and an updated record of Belum-Temengor Forest Reserve. In this survey, a total of 27 species of herpetofauna was recorded comprising 12 species of amphibians from four families and 15 species of reptiles from six families. No new records of frog or lizard species are reported in this study. However, three new records of snakes are reported from the area