The synlophe of Batrachonema synaptospicula Yuen, 1965 collected from Rana limnocharis Boie, 1835 of peninsular Malaysia was found to be identical morphologically to that in the specimens from Rana narina Stejneger, 1901 of Okinawa, and R. limnocharis of Taiwan. In the midbody, 20-22 ridges are present, and the ridges increase gradually in size and are oriented from right to left in the dorsal and left ventral fields, whereas the right ventral ridges are small and almost perpendicular to the body wall. The orientation of ridges from right to left is considered to be a key characteristic of the genus Batrachonema. Because Amphibiophilus ranae Wang et al., 1978 and Amphibiophilus sp. from R. limnocharis of south China are regarded to be conspecific with B. synaptospicula, this nematode is surmised to be distributed widely in southeast and east Asia.
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.
A new nematode species, Paraphilometroides nemipteri sp. n. is described from the female specimens collected from the dorsal fin and operculum of the marine perciforme fish, Nemipterus peronii off Kuala Terengganu coastal waters in Malaysia. It considerably differs from all other species in Philometridae in the structure of the head end (presence of wide dorsal and ventral cephalic cuticular alae supported by special inner transverse muscular formations) and, therefore, a new genus Paraphilometroides gen. n. has been erected to accommodate it. Additional characteristic features of P. nemipteri are the presence of cuticular bosses on the body, eight cephalic papillae in the outer circle and four small papillae in the inner circle, and the absence of caudal protrusions.
The prevalence of Capillaria hepatica (Bancroft, 1893) infection in a total of 2324 rats trapped from 25 localities in West Malaysia was 15.5%. Infection rates in males (16.0%) and females (15.1%) are similar. A significantly higher percentage of adults (18.1%) than young (7.7%) was infected. Capillaria hepatica infection rates among urban (0.7%) and jungle (0.0%) rats was very low as compared to field rats (17.7%) trapped from agricultural areas such as oil palm estates and rice growing areas. Prevalence of C. hepatica infection in rats is not evenly distributed throughout West Malaysia. There seem to be localised foci of infection. In some areas as many as 77.8% of the adult rats are found to be infected while in other areas the same species of rats are found free of infection.
Five species of adult nematodes, unidentifiable nematode larvae, and three species of acanthocephalans, were found in freshwater ornamental fishes newly imported into Germany from Brazil, Colombia, Indonesia, Malaysia, Nigeria, Peru, Sri Lanka and Thailand. The following species were identified: Adult Nematoda: Pseudocapillaria tomentosa, Capillariidae gen. sp., Dichelyne hartwichi sp. n., Procamallanus (Spirocamallanus) pintoi and Spinitectus allaeri; Acanthocephala: Pseudogorgorhynchus arii gen. et sp. n., Neoechinorhynchus sp. and Pallisentis sp. The nematode Dichelyne hartwichi sp. n. (male only) from the intestine of Chelonodon fluviatilis (Hamilton) from Thailand is characterised mainly by the presence of minute cuticular spines on the tail tip, length of spicules (510 microns) and arrangement of caudal papillae. The acanthocephalan Pseudogorgorhynchus arii sp. n. from the intestine of Ariopsis seemanni (Günther) from Colombia represents a new genus Pseudogorgorhynchus gen. n., differing from other genera of the Rhadinorhynchidae mainly in possessing a small proboscis armed with markedly few (18) hooks arranged in six spiral rows. Spinitectus macheirus Boomker et Puylaert, 1994 and Spinitectus moraveci Boomker et Puylaert, 1994 are considered junior synonyms of Spinitectus allaeri Campana-Rouget, 1961.
Gonadectomized male albino rats aged 7 weeks were given 1.5 mg/kg testosterone propionate daily and inoculated with 50 third-stage larvae of Angiostrongylus malaysiensis. The treatment significantly increased the number of larvae and adult worms recovered from the brain and pulmonary arteries, respectively, and the rats exhibited smaller thymus glands. The total numbers of leukocytes, monocytes, neutrophils, and especially eosinophils increased significantly post-infection, but the counts were higher in the untreated infected controls. Presumably, immunosuppressive effects of testosterone may at least partly be responsible for the higher loads of A. malaysiensis worms found in male rats as compared with females in the field.
Splenic nodules from 38 cynomolgus monkeys (Macaca fascicularis) which were captured in Malaysia and Indonesia were studied histologically. The lesions were characterized by well-circumscribed focal fibrosis, accumulation of eosinophils and histiocytes, hemorrhage or hemosiderosis, and loss of normal splenic architecture. Small arteries in the lesion frequently had intimal thickening and narrowing of the lumen in addition to the presence of microfilariae. Microfilariae were also seen in the extravascular area of the lesion, and were occasionally engulfed by multinucleated giant cells. The splenic lesion was thought to have been initiated by incomplete infarction caused by intimal thickening and microfilarial occupation of the small arteries.
The prevalence and intensity of intestinal nematode infections were assessed during 3 anthelminthic interventions in an urban community in Malaysia. The prevalence levels of Ascaris lumbricoides at Interventions 1, 2 and 3 were 30.6%, 18.9% and 15.5%, respectively and the mean intensities were 1.9, 0.75 and 0.81 worms per person. For Trichuris trichiura, the prevalence levels at Interventions 1, 2 and 3 were 46.9%, 21.6% and 15.7%, respectively. The mean intensities for T. trichiura at Interventions 1, 2 and 3 were 3.30, 0.92 and 0.07 worms per person. No gender-related prevalence and intensity were observed for the two geohelminths in this community. Prevalences and intensity had convex age profiles. Although repeated chemotherapeutic intervention reduced both prevalence and intensity levels, intensity was a more sensitive indicator than prevalence. The results indicate that age-targetting treatment at school children of 7-12 years of age would be an appropriate strategy for this community.
Soil-transmitted helminth (STH) infections are the most common intestinal parasitic infections of medical importance in humans. The infections are widely distributed throughout tropical and subtropical countries, particularly among disadvantaged and underprivileged communities. In Malaysia, STH infections is highly prevalent, especially among the indigenous groups. However, species identification through molecular studies is still lacking. Using molecular techniques, this study was conducted to identify STH species that infect humans. Faecal samples were collected from three Iban tribal longhouses in the rural area of Sarikei Division, Sarawak. Positive faecal samples by microscopy were subjected to PCR and sequenced for species identification. Based on the microscopy examination, the most prevalent STH infection was Ascaris, followed by hookworm and Trichuris. All microscopy-positive samples were then PCR-amplified. The amplicons were sequenced, aligned, and compared with other sequences in the GenBank database. The results showed that Ascaris lumbricoides was the predominant STH species, followed by Trichuris trichiura, Ancylostoma duodenale, and Necator americanus. Our findings were contradictory to past studies, as we showed that A. duodenale was more abundant than N. americanus. Socioeconomic improvement and health education programs should be included in the management and prevention of public health strategies against STH.
Orang Asli are the indigenous minority peoples of peninsular Malaysia. Despite proactive socioeconomic development initiated by the Malaysian Government in upgrading the quality of life of the Orang Asli communities since 1978, they still remained poor with a current poverty rate of 76.9%. Poverty exacerbates the health problems faced by these communities which include malnourishment, high incidences of infectious diseases (eg. tuberculosis, leprosy, malaria) and the perpetual problem with intestinal parasitic infections. Studies reported that the mean infection rate of intestinal parasitic infections in Orang Asli communities has reduced from 91.1% in 1978, to 64.1% in the subsequent years. Although the results was encouraging, it has to be interpreted with caution because nearly 80% of studies carried out after 1978 still reported high prevalence (i.e. >50%) of soil-transmitted helminthiases (STH) among Orang Asli communities. Prior to 1978, hookworm infection is the most predominant STH but today, trichuriasis is the most common STH infections. The risk factors for intestinal parasitic infections remained unchanged and studies conducted in recent years suggested that severe STH infections contributed to malnutrition, iron deficiency anaemia and low serum retinol in Orang Asli communities. In addition, STH may also contribute to poor cognitive functions and learning ability. Improvements in socioeconomic status in Malaysia have shown positive impact on the reduction of intestinal parasitic infections in other communities however, this positive impact is less significant in the Orang Asli communities. In view of this, a national parasitic infections baseline data on morbidity and mortality in the 18 subgroups of Orang Asli, will assist in identifying intervention programmes required by these communities. It is hope that the adoption of strategies highlighted in the World Health Organisation- Healthy Village Initiatives (WHO-HVI) into Orang Asli communities will ensure the whole mechanism of delivery and empowerment by the government agencies become more efficient and productive in alleviating intestinal parasitic infections in these communities.
The approaches of transcriptomic and proteomic have been widely used to study host-pathogen interactions in fish diseases, and this is comparable to the recently emerging application of metabolomic in elucidating disease-resistant mechanisms in fish that gives new insight into potential therapeutic strategies to improve fish health. Metabolomic is defined as the large-scale study of all metabolites within an organism and represents the frontline in the 'omics' approaches, providing direct information on the metabolic responses and perturbations in metabolic pathways. In this review, the current research in infectious fish diseases using metabolomic approach will be summarized. The metabolomic approach in economically important fish infected with viruses, bacteria and nematodes will also be discussed. The potential of the metabolomic approach for management of these infectious diseases as well as the challenges and the limitations of metabolomic in fish disease studies will be explored. Current review highlights the impacts of metabolomic studies in infectious fish diseases, which proposed the potential of new therapeutic strategies to enhance disease resistance in fish.
Lambs with the Major Histocompatibility Complex DRB1*1101 allele have been shown to produce fewer nematode eggs following natural and deliberate infection. These sheep also possess fewer adult Teladorsagia circumcincta than sheep with alternative alleles at the DRB1 locus. However, it is unclear if this allele is responsible for the reduced egg counts or merely acts as a marker for a linked gene. This study defined the MHC haplotypes in a population of naturally infected Scottish Blackface sheep by PCR amplification and sequencing, and examined the associations between MHC haplotypes and faecal egg counts by generalised linear mixed modelling. The DRB1*1101 allele occurred predominately on one haplotype and a comparison of haplotypes indicated that the causal mutation or mutations occurred in or around this locus. Additional comparisons with another resistant haplotype indicated that mutations in or around the DQB2*GU191460 allele were also responsible for resistance to nematode infections. Further analyses identified six amino acid substitutions in the antigen binding site of DRB1*1101 that were significantly associated with reductions in the numbers of adult T. circumcincta.