Many trichostrongyloid species parasitizing rodents in Malaysia were described in 1967 in a thesis that was never published. Some of these species have since been redescribed sometimes with, sometimes without reference to the thesis. The remaining species are redescribed using information given in the thesis and certain additional morphological data (in particular, the synlophe) taken from study of the paratypes. The species are reclassified according to criteria established in the most recent classification. The following genera are proposed: Brevistriatinae: - Macrostrongylus n. gen. characterized by a caudal bursa of Calypsostrongylus type and absence of synlophe. Nippostrongylinae: - Malaistrongylus n. gen. characterized by a synlophe of Heligmonoides type but with a larger number of ridges and by the fusion of rays 4 and 5 in the caudal bursa. - Rattus strongylus n. gen. characterized by small, subequal dorsal left ridges and a total number of ridges less than 20. - Sabanema n. gen. characterized by small subequal dorsal left ridges and a total number of ridges greater than 30. The species under consideration are the following: Hepatojarakus malayae Yeh, 1955; Pithecostrongylus bicapitatus n. sp. (= P. bicapitatus Ow Yang, 1967, in litt); Macrostrongylus ratti n. gen., n. sp. (= Macrostrongylus ratti Ow Yang, 1967, in litt.); Calypsostrongylus malayensis Durette-Desset, 1976 (= Brevistriata malayensis Ow Yang, 1967, in litt); Fissicauda callosciuri (Supperer et Kutzer, 1964); Fissicauda brevispicula n. sp. (= Brevistriata brevispicula Ow Yang, 1967, in litt.); Nippostrongylus brasiliensis (Travassos, 1914); Orientostrongylus tenorai Durette-Desset, 1970 (= Longistriata selangora Ow Yang, 1967, in litt.); O. krishnansamyi Durette-Desset et Lim-Boo-Liat, 1974 (= Longistriata malaccae Ow Yang, 1967, in litt.); Heligmonoides bulbosus n. sp. (= Heligmonina (Heligmonoides) bulbosa Ow Yang, 1967, in litt.); Heligmonoides lanceolatus n. sp. (= Heligmonina (Heligmonoides) lanceolata Ow Yang 1967, in litt.); Malaistrongylus odontospicularis n. gen., n. sp. (= Malaistrongylus odontospicularis Ow Yang, 1967, in litt.); Paraheligmonelloides triangulus n. sp. (= Longistriata triangulum Ow Yang, 1967, in litt.); P. annandalei n. sp. (= Longistriata annandalei Ow Yang, 1967, in litt.); P. rajah n. sp. (= Heligmonina (Heligmonoides) rajah Ow Yang, 1967, in litt.); Rattustrongylus odontoconus n. gen., n. sp. (= Longistriata odontocona Ow Yang, 1967, in litt.); R. rotundoconus n. sp. (= Longistriata rotundocona Ow Yang, 1967, in litt.); Sabanema sabana n. gen., n. sp. (= Longistriata sabana Ow Yang, 1967, in litt.); S. kepongi n. sp. (= Longistriata kepongi Ow Yang,
Description of four new species of Heligmosome Nematodes parasites of the gut of Trichys lipura: --Heligmonella limbooliati n. sp. has a synlophe of Heligmonella-type and a bursa related to Cordicauda. --Cordicauda trichysi n. sp. is characterized by the relatively small dorsal lobe of the bursa, numerous cuticular ridges and the origin of the 8th rib at the distal third of the dorsal rib. --C. malayensis is closely related to C. trichysi (the female of the two species are morphologically identical but the two species can be separated by the larger dorsal lobe of the bursa and the longer spicula of C. malayensis). --C. magnabursa n. sp. is separated from the other species of the genus by the peculiar morphology of the bursa and the female's tail, dorsally bent. The fauna of Trichys is compared to that of Atherurss africanus, which is parasitized by 8 coparasites species: One Heligmonella and seven Paraheligmonina. From a phyletic as well as an ecological point of view (relative abundance and species location in the gut) the two fauna seem to have evolved in a parallel way, one in Africa, one in Asia, from a single Heligmonella type Nematode, after the host's partition.
The fleas (Siphonaptera: Pygiopsyllidae) Farhangia quattuordecimdentata sp. n. and Farhangia sedecimdentata sp. n. are described from pygmy squirrels (Prosciurillus spp.), and Nestivalius sulawesiensis sp. n. from murine rodents, all from Sulawesi, Indonesia. Both new species of Farhangia were collected in Central Sulawesi (Sulawesi Tengah); F. quattuordecimdentata sp. n. was recovered mainly from P. murinus, whereas F. sedecimdentata sp. n. was recovered mainly from P. leucomus. These new species are compared with the two previously described species of Farhangia: F. celebensis (Ewing) from P. murinus in North Sulawesi (Sulawesi Utara) and F. sciuri (Ewing) from the tree squirrel Callosciurus prevosti in Sabah (Borneo). Nestivalius sulawesiensis sp. n. was collected from six species of endemic murine rodents in both North and Central Sulawesi. It is compared to the morphologically similar N. pomerantzi (Traub) from Mindanao, which parasitizes murine hosts that are endemic to the Philippines.
Linear stability analysis was used to investigate the onset of Marangoni convection in a two-layer system. The system comprised a saturated porous layer over which was a layer of the same fluid. The fluid was heated from below and the upper free surface was deformable. At the interface between the fluid and the porous layer, the Beavers-Joseph slip condition was used and in the porous medium the Darcy law was employed to describe the flow. Predictions for the onset of convection were obtained from the analysis by the perturbation technique. The effect of surface deformation and depth ratio, z (which is equal to the depth of the fluid layer/depth of the porous layer) on the onset of fluid motion was studied in detail.
Hantaviruses are infectious agents that can cause diseases resulting in deaths in humans and are hosted by rodents without affecting the hosts themselves. A simple mathematical model describing the spread of the Hantavirus infection in rodents has been proposed and developed by Abramson and Kenkre where the model takes into account the temporal and spatial characteristics of this infection. In this paper, we extended this model to include the process of harvesting and study the impact of different harvesting strategies in the spread of the Hantavirus infection in rodents. Several numerical simulations were carried out and the results are discussed.
Field surveys of ectoparasites on rodents and scandents were conducted in four localities of wildlife reserves in Peninsular Malaysia from October 2008 to November 2009. A total of 16 animals comprising 5 species of hosts were caught and examined for ectoparasites. The hosts examined were Maxomys rajah, Maxomys whiteheadi, Leopoldamys sabanus, Lariscus insignis and Tupaia glis. Of these hosts, 9 genera, consisting of 14 species of ectoparasites were extracted. Three species of ticks (Ixodidae), 7 species of mesostigmatid mites (Laelaptidae), 3 species of chiggers (Trombiculidae) and 1 species of listrophorid mites (Listrophoriidae) were identified. The infestation rate of ectoparasites observed ranged from 12.5% to 62.5%. Among the ectoparasites found, Ixodes granulatus and Leptotrombidium deliense are of known medical importance.
Fifty-one Rickettsia tsutsugamushi isolates from small mammals collected in central Peninsular Malaysia serologically characterized by direct immunofluorescence using eight prototype strains. Karp-related (TA763, TA686, TA716) antigens were found in 90.2% of the isolates.
1. Electrophoretic variations of 9 erythrocyte proteins, coded by a separate gene locus each, were analysed in and among the 5 Malayan species of Rattus belonging to the subgenus Lenothrix. 2. The average proportion of loci heterozygous per individual for the taxa analysed is 0.037. 3. The results obtained confirm the specific status of the 5 taxa studied. With respect to the relative affinities among the species studied, the present results could resolve the discrepancies between conclusions based on morphological evidence and those based on cytological evidence. 4. The 5 species of Rattus studied may be assigned to 4 groups and comparative data suggest that these groups are relatively distantly related to one another.
Leptotrombidium (Leptotrombidium) arenicola Traub, a vector of scrub typhus, had previously been found to occur in the coastal vegetation behind the edge of open sand along the beaches of Peninsular Malaysia. Surveys of the west coast beaches of Sabah and Sarawak were conducted to determine if this species occurs in similar habitat in East Malaysia on the island of Borneo. Leptotrombidium (L.) arenicola was not collected from the eighteen sites studied. Of the 11,982 mite larvae collected, 55 per cent were L.(L.) deliense (Walch), a well-known, widespread vector of scrub typhus.
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.
The Borrelia genus consists of spirochete bacteria known to cause Lyme disease (LD) and relapsing fever in humans. Borrelia pathogens are commonly transmitted via arthropod vectors such as ticks, mites, or lice. Here, we report the molecular screening of LD group Borrelia sp. from ticks (Acari: Ixodidae) collected from rodents trapped in recreational forests and a semiurban residential area in the Selangor state in Malaysia. Of 156 adult ticks surveyed, 72 ticks were determined as positive for Borrelia sp. by polymerase chain reaction (PCR). All Borrelia PCR-positive ticks belonged to the Ixodes granulatus Supino species. Borrelia sp. was not detected in other tick species examined, including Dermacentor sp. and Amblyomma sp. ticks. Thirteen Borrelia PCR-positive tick samples were selected for further sequence analyses. Phylogenetic analyses of partial flaB gene sequences revealed that the Borrelia sp. were closely related to the LD group borreliae, Borrelia yangtzensis; a novel Borrelia genospecies reported in East Asian countries including Japan, Taiwan, and China. To our knowledge, this is the first report of Borrelia sp. related to Borrelia yangtzensis detected in Malaysia and Southeast Asia. The zoonotic potential of the Borrelia sp. reported here merits further investigation, as it may explain the previously reported serological evidence for borrelial infections in Malaysia.
Neodiplostomum (Conodiplostomum) ramachandrani Betterton, 1976 has been reported from four species of rodent hosts: Echinosorex gymnurus (Raffles): Rattus whiteheadi (Thos); R. muelleri (Jentink) and Callosciurus notatus (Boddaert). A comparison of trematodes recovered from these hosts revealed patterns of host-induced morphological variation taking place. Because N. (Conodiplostomum) ramachandrani shows little generic difference from Fibricola intermedius (Pearson, 1959) Sudarikov, 1960 it is transferred to the genus Fibricola and is now designated Fibricola ramachandrani (Betterton, 1976) Palmieri, Krishnasamy and Sullivan.
Leptospirosis, a widespread zoonotic disease, is a public health problem, especially in major urban centres, and is mainly reported to be associated with rats. In Malaysia, focus has been primarily given to the Leptospira prevalence in rodents per se, but there is lack of information on the microhabitat structure of the outbreak areas. We aimed to determine the diversity of small mammal species, microhabitat types, and their prevalence of pathogenic Leptospira spp. in the outbreak areas, which were categorized as urban, semi-urban, and recreational forests. Sampling involved deploying 100 to 300 live traps at each study site. Kidney samples were extracted from selected individuals, for screening of pathogenic Leptospira spp. by PCR. Out of 537 individuals from 15 small mammal species captured, 4 species were recorded from urban, 13 from semi-urban, and 11 from recreational forest sites. From 389 individuals screened, 58 were tested positive for pathogenic Leptospira. Recreational forests recorded the highest prevalence with 19.4% (n = 93), followed by urban, 16.6% (n = 163) and semi-urban sites with 9.8% (n = 133). Seven rodent species were tested positive for pathogenic Leptospira from all areas. R. norvegicus was found to harbour the highest prevalence (66.7%) in urban, R. rattus (53.8%) in semi-urban, whereby M. whiteheadi (44.4%) in recreational forest sites. Microhabitat analysis revealed that rubbish quantity contributed especially strongly to a high prevalence of Leptospira. This study contributes to understanding of the host and microhabitat preferences of Leptospira, which is important in controlling the spread of this disease in human's landscapes.
Hemoprotozoans are important pathogens of animals and humans, among which some species have zoonotic significance. The prevalence of different hemoprotozoa and Anaplasma spp. in larger mammals have been reported from different regions of the world. But, very few studies have been conducted to estimate the prevalence of hemoprotozoa in rodents and shrews of South-East Asia. The study assessed the prevalence of hemoprotozoa and Anaplasma spp. in rodents and shrews of Bangladesh. Blood samples (n=451) were collected from rodents and shrews between June 2011 and June 2013 and July-December 2015 from 4 land gradients of Bangladesh. Giemsa-stained blood smears revealed that 13% of animals were harboring hemoprotozoa (4.7% Babesia spp., 0.67% Plasmodium spp.), and Anaplasma spp. (7.5%). The study may serve as a guide for future hemoparasitic research of rodents and shrews.