Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of
distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since
it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic
sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal
zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core
was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone
respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be
due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the
density data indicated the highest degree of scattering and an over-lapping condition for those intertidal and sub-tidal
samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the subtidal
(reaching 90%) in the first sampling before both became no significant different in the second sampling. It could
indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos
could indicate their response towards the environmental condition in the area which will only be confirmed by long term
ecological study.
The current information on isoenzyme studies of nematode parasites was reviewed. The genetic heterogeneity as reviewed by these studies was highlighted. Application of isoenzyme studies and the role of biotechnological techniques in isoenzyme studies was discussed, and the status of cytogenetic studies on nematode parasites was presented.
A collection of parasitic worms was made from Rattus rattus jarak (Bonhote) from Pulau Jarak, “which lies in the middle of the Malacca Straits between Penang and Port Swettenham and some 85 miles from the Sembilan Islands opposite the Dindings.” (Audy, 1950). It was collected by Dr. J. R. Audy, Senior Research Officer of the Division of Virus Research and Medical Zoology, Institute for Medical Research, Kuala Lumpur while investigating scrub-typhus on the island.
Hard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5-10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.
Haemonchosis is a common problem on goat farms in tropical countries such as Malaysia. Prevention of production losses generally depends on the use of anthelmintic drugs, but is threatened by the emergence of anthelmintic resistance. This study investigates anthelmintic efficacy on small-scale Malaysian goat farms and describes putative risk factors. Adult goats had moderate to high pre-treatment faecal trichostrongyle egg counts, despite being housed on slatted floors and fed on cut-and-carry forage, raising questions about the source of nematode infection. Our results show multiple resistance to benzimidazole and macrocyclic lactone anthelmintic drugs and allow us to discuss the genetic origins of resistance with reference to farm husbandry and management. We conclude that improvement in Malaysian goat production efficiency will require the development of sustainable helminth control strategies, underpinned by a better understanding of the origins and population genetics of anthelmintic resistance.
Unidentified mermithid nematodes were found in the abdominal cavity of three species of Anopheles mosquitoes from LAO PDR. This is a first record of mermithid nematodes in adult mosquitoes from Lao PDR. Two worms were found in each adult host and the infection was more prevalent in the northern region compared to the south.
Gastrointestinal nematodes can cause assorted health problems to human and other primates. The status of gastrointestinal nematodes in non-human primates remained less documented in Malaysia. This study aimed to determine the occurrence of gastrointestinal nematodes recovered from the fecal samples of captive non-human primates at the Matang Wildlife Centre (MWC), Sarawak. Fresh fecal samples were collected from 60 non-human primates of six species (i.e. Orangutan, Bornean gibbon, Silvered Leaf monkey, Slow loris, Pig-tailed macaque, and Long-tailed macaque) and processed using simple fecal floatation method and fecal sedimentation method. This study shows high prevalence of nematode infection (>=50%) and co-infection (22 from 45 infected individuals) in all species of captive non-human primates found in MWC, except one individual of young Silvered Leaf monkey was negative for nematode. From these, eight genera of 11 species and one unknown nematode larvae were recovered and among them Oesophagostomum sp., Ascaris sp., and Strongyloides sp. were the most common nematodes infecting the non-human primates. All the Bornean gibbon (n=7) were found to be infected with nematodes. Moreover, Long-tailed macaques at the centre were heavily infected by Ascaris sp. (number of total count, nt = 2132; total mean abundance, MA=113.70). This is the first report of high prevalence nematode infection on multiple species of captive non-human primates in a wildlife centre located in Sarawak. Some of the nematodes are of zoonotic potential. This information is important for health care management, both in-situ and ex-situ conservations of captive and free-ranging nonhuman primates.
A total of 2,337 rodents trapped from various parts of Peninsular Malaysia were dissected and studied for the distribution and prevalence of parasitic infections. Four new rodent hosts for Sarcocystis in Malaysia are reported (Bandicota indica, Rattus sabanus Rattus argentiventer and Rattus norvegicus). Sarcocystis was found in 17.2 percent of the rodents examined. Rattus annandalei, Rattus tiomanicus and Rattus norvegicus are new hosts of Syphacia muris in Peninsular Malsysia. Rattus sabanus was found to be infected with Zonorchis borneonenis. Brachylaima ratti Baugh, 1962 was recovered from the small intestine of Rattus rattus diardii for the first time in Malaysia. The prevalence and distribution of other parasites are also discussed.
We redescribe the camallanid nematode Serpinema octorugatum (Baylis, 1933) from the box turtle Cuora amboinensis (Daudin) collected in Malaysia. In this redescription, we amend the original description by noting that there are only four cephalic papillae and that there are five pairs of post-anal papillae, and propose that the name of this species be corrected from S. octorugatus to S. octorugatum. Additionally, we removed the tissues overlying the buccal capsule and have used SEM studies to show that the peribuccal shields extend laterally from the buccal capsule, forming a surface possibly used in muscle attachment. Furthermore, we show that the supposedly non-cuticularised cylinder connecting the buccal capsule to the oesophagus in the Camallanidae is part of the buccal capsule and is, therefore, likely to be cuticularised. We also examine morphological measurements of taxonomic interest for correlations with total body length and find that many characters traditionally used for inter- and intra-specific comparisons are correlated with total body length in adult female worms. This suggests that comparisons between samples of adult female worms that do not account for the potential effect of total body length may be misleading. However, we show that some features of taxonomic interest are not correlated with total body length.
A cross-sectional study of intestinal parasitic infections amongst migrant workers in Malaysia was conducted. A total of 388 workers were recruited from five sectors including manufacturing, construction, plantation, domestic and food services. The majority were recruited from Indonesia (n = 167, 43.3%), followed by Nepal (n = 81, 20.9%), Bangladesh (n = 70, 18%), India (n = 47, 12.1%) and Myanmar (n = 23, 5.9.2%). A total of four nematode species (Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms), one cestode (Hymenolepis nana) and three protozoan species (Entamoeba histolytica/dispar, Giardia sp. and Cryptosporidium spp.) were identified. High prevalence of infections with A. lumbricoides (43.3%) was recorded followed by hookworms (13.1%), E. histolytica/dispar (11.6%), Giardia sp. (10.8%), T. trichura (9.5%), Cryptosporodium spp. (3.1%), H. nana (1.8%) and E. vermicularis (0.5%). Infections were significantly influenced by socio-demographic (nationality), and environmental characteristics (length of working years in the country, employment sector and educational level). Up to 84.0% of migrant workers from Nepal and 83.0% from India were infected with intestinal parasites, with the ascarid nematode A. lumbricoides occurring in 72.8% of the Nepalese and 68.1% of the Indian population. In addition, workers with an employment history of less than a year or newly arrived in Malaysia were most likely to show high levels of infection as prevalence of workers infected with A. lumbricoides was reduced from 58.2% to 35.4% following a year's residence. These findings suggest that improvement is warranted in public health and should include mandatory medical screening upon entry into the country.
The amended diagnosis of the genus Pratylenchoides and list of its valid species with synonyms are given. All the efficient diagnostic characters are listed. Modern taxonomic standard for the description of Pratylenchoides species is proposed; it may be used also in taxonomic databases. Tabular and text keys for all species of the genus are given. Five following groups are considered within the genus Pratylenchoides. The group arenicola differs from other groups in the primitive adanal bursa type; the groups magnicauda, crenicauda, ritteri, and megalobatus differ from each other in the position of cardium along the body axis in relation to the pharyngeal gland nuclei, pharynx types are named according to the stages of its evolution from the primitive tylenchoid pharynx (cardium situated posteriorly) to the advanced hoplolaimoid one (cardium situated anteriorly). Diagnoses and species compositions of the groups are given. Basing on the matrix of species characters, the dendrogram has been generated for all species of Pratylenchoides and for all characters (UPGMA, distance, mean character difference, random, characters ordered). Taking in view that the PAUP software gives equal weights to all characters, including the most important ones which define the prognostic species groups, the separate dendrograms for each prognostic species group were generated using the same above mentioned tree parameters. On the base of the records of Pratylenchoides species the matrices of plant host ranges, geographic distribution, and preferred soil-climatic conditions were developed. The dendrograms of the faunal similarities were generated using these matrices, with conclusions on a possible origin and evolution of the genus. The genus evolved from the flood lands with swampy soils and prevalence of dicotyledons (herbaceous Lamiaceae and woody Salicaceae families) to the forest mainland communities with balanced humidity and predominance of herbaceous Poaceae and Fabaceae with woody Fagaceae, Betulaceae, and Oleaceae. The leading factor of the evolutional adaptation to soil-climatic conditions was the factor of humidity, but its significance gradually decreased with the host change to more advanced plant taxa adapted to the communities with more dry balanced humidity. The genus took its origin on the south shores of Laurasia in the Cainozoe. Later, when Hindistant and Arabian Peninsula joined with Laurasia creating the Himalayas barrier, the Pratylenchoides spp. distributed by two branches: the northern one moved into Central Asia, East Europe and North America, and the south branch came into Indo-Malaya, West Asia and the north of Africa. The remnants of the ancient species groups remain in West Europe and East Asia. In the North America the genus gave an origin to its sister genus Apratylenchoides, which spread to the south up to Antarctica; another advanced branch spread in the North America reaching Alaska.
Faecal samples were collected from 48 randomly selected smallholder goat farms in northern Peninsular Malaysia. The nematode eggs extracted were tested for resistance to thiabendazole using the egg hatch assay technique. Thiabendazole resistance was found on 19% of farms tested.
Tarsubulura perarmata (Ratzel, 1868) is described from a primate Tarsius bancanus and from Tupaidae: Tupaia glis and T. minor in Malaysia (Kuala Lumpur). Its biological cycle is done by the experimental infestation of crickets belonging to the genera Valanga and Oxya. The infective larvae are obtained after three weeks of development of 28 degrees C in the intermediate host. They differ from third stage larvae obtained from Subulurinae by the development of cuticular pharyngeal lobes. The early apparition of this ontogenetic character confirms the isolation of the genus Tarsubulura as compared to the general evolution of the Subuluridae.
Description of the male Pterygodermatites nycticebi (Mönnig, 1920) unknown until the present study, and a study of the cephalic and cuticular structures of the female. This rictularid has a morphological evolution comparable to that of other males of the Rictulariidae parasitic in viverrid carnivores and in primates.
Culicoides Latreille biting midges are important blood feeding insects. Many species are pests and vectors of the disease causing agents including viruses, protozoa and filarial nematodes which can be transmitted to humans and other animals. However, knowledge of the role of Culicoides as vectors of filarial nematodes is limited, particular in Thailand, where at least 100 species of the genus Culicoides have been reported. In this study, a molecular approach using the 12S rRNA gene sequence was used to detecting the filarial nematode in four common biting midge species, C. actoni Smith, C. oxystoma Kieffer, C. peregrinus Kieffer and C. mahasarakhamense Pramual, Jomkumsing, Piraonapicha & Jumpato in animal shelters from northeastern Thailand. A total of 1,721 specimens were used for molecular screening. An unidentified Onchocercidae sp. was detected in a specimen of C. mahasarakhamense collected from Maha Sarakham province. This filarial species shows 93% sequence similarity with an unidentified Onchocercidae sp. isolated from Culex mosquitoes. Phylogenetic analyses revealed that Onchocercidae sp. from C. mahasarakhamense formed a clade with strong bootstrap support (100%) with filarial species detected in birds. Thus, it is very likely that the Onchocercidae sp. found in this study employes birds as vertebrate hosts which agrees with feeding behavior of C. mahasarakhamense which is known to feed on chicken. Further study is requiring to examine whether this biting midge species is a competent vector of this Onchocercidae sp.