Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys' Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L(-1), COD 10 234 ± 175 mg L(-1), ammonical nitrogen of 880 ± 74 mg L(-1), benzene 0.22 ± 0.1 mg L(-1) and toluene 1.2 ± 0.4 mg L(-1). The 50% lethality concentration (LC(50)) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.
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.
Two groups of goats were experimentally infected with two different strains of Haemonchus contortus and compared with the controls. Group A animals were infected with a goat-derived strain (GDS) while Group B animals were infected with a sheep-derived strain (SDS). Changes in the liveweights and some blood constitutents between the two infected groups were compared. The pathogenic effects of the GDS larvae were generally more serious when compared with those of the SDS larvae.
In 3 urban areas in Selangor, Peninsular Malaysia between 1973 and 1981, blood from 4084 dogs was examined for haematozoa. The following frequencies were found: Babesia gibsoni 17.7%; microfilariae of Dirofilaria immitis 9.6%; Hepatozoon canis 1.2%; B. canis 1.1%; Ehrlichia canis 0.2%; Trypanosoma evansi 0.1%. A detailed examination of B. gibsoni infections and microfilariasis due to D. immitis with regards to monthly distribution, breed frequency, sex and age, revealed that pedigree and non-pedigree dogs were equally susceptible to Babesia and microfilariae infections.
The aetiopathogenesis of medial coronoid disease (MCD) remains obscure, despite its high prevalence. The role of changes to subchondral bone or articular cartilage is much debated. Although there is evidence of micro-damage to subchondral bone, it is not known whether this is a cause or a consequence of MCD, nor is it known whether articular cartilage is modified in the early stages of the disease. The aim of the present study was to use equilibrium partitioning of an ionic contrast agent with micro-computed tomography (microCT) to investigate changes to both the articular cartilage and the subchondral bone of the medial coronoid processes (MCP) of growing Labrador retrievers at an early stage of the disease and at different bodyweights. Of 14 purpose-bred Labrador retrievers (15-27 weeks), six were diagnosed with bilateral MCD and one was diagnosed with unilateral MCD on the basis of microCT studies. The mean X-ray attenuation of articular cartilage was significantly higher in dogs with MCD than in dogs without MCD (P<0.01). In all dogs, the mean X-ray attenuation of articular cartilage was significantly higher at the lateral (P<0.001) than at the proximal aspect of the MCP, indicating decreased glycosaminoglycan content. Changes in parameters of subchondral bone micro-architecture, namely the ratio of bone volume to tissue volume (BV/TV), bone surface density (BS/TV), bone surface to volume ratio (BS/BV), trabecular thickness (Tb.Th; mm), size of marrow cavities described by trabecular spacing (Tb.Sp; mm), and structural model index (SMI), differed significantly by litter (P<0.05) due to the difference in age and weight, but not by the presence/absence of MCD (P>0.05), indicating that subchondral bone density is not affected in early MCD. This study demonstrated that cartilage matrix and not subchondral bone density is affected in the early stages of MCD.
Studies on fungal taxonomy and fungal diversity are crucial for a better understanding of the interactions between fungi and their habitats. To date, there is no published record on macrofungal diversity in Pulau Bidong, Terengganu. Therefore, this study aimed to identify macrofungi species found with their respective substrates and to determine the macrofungal diversity in the island. The study was conducted at two different occasions and comprised of two trails near Universiti Malaysia Terengganu Research Station in Pulau Bidong, Terengganu. Collectionof fresh macrofungi was made and additional data including host information, distinctive features of each fungal sample and several environmental parameters was also recorded. Fresh specimens were later observed and identified before being dried prior to storage. Overall, 65 macrofungal species with 2 unidentified species belonging to 21 families and 34 genera were recorded. Trail A and trail B recorded diversity index of2.67 and 3.14 for Shannon Index while Simpson index recorded 0.90 and 0.94 respectively. The macrofungal diversity was dominated by family Polyporaceae while rare species discovered were from family of Tricholomataceae, Hericiaceae, Stereaceae, Schizophyllaceae, Sclerodermataceae, Dacrymycetaceae, Tremellaceae, Russulaceae and Clavulinaceae. The most common macrofungal substrates was decayed branches while other macrofungal substrates found were decayed trunks and leaves, soil,termite mounds, and living tree. In conclusion, the macrofungal species were randomlydistributed with high diversity in both trails. Therefore, it is recommended that anincrease in sampling trips, sampling efforts and areas covered be provided to increase the number of macrofungal species discovered and accuracy of diversity studies in the future.
DNA fingerprinting with the insertion sequence IS6110 (also known as IS986) has become established as a major tool for investigating the spread of tuberculosis. Most strains of Mycobacterium tuberculosis have multiple copies of IS6110, but a small minority carry a single copy only. We have examined selected strains from Malaysia, Tanzania and Oman, in comparison with M. bovis isolates and BCG strains carrying one or two copies of IS6110. The insertion sequence appears to be present in the same position in all these strains, which suggests that in these organisms the element is defective in transposition and that the loss of transposability may have occurred at an early stage in the evolution of the M. tuberculosis complex.
The filaria vector competence of Anopheles stephensi was compared with Brugia-susceptible Aedes aegypti Liverpool strain, An. gambiae Badagry Lagos strain and An. dirus Perlis Malaysia strain. An. stephensi ingested more Brugia pahangi microfilariae, had the highest infectivity rate and yielded more infective mosquitoes than the other two anopheline species. The overall vector competence of An. stephensi was 0.13 times that of Ae. aegypti, 0.62 times that of An. gambiae and 2.17 times that of An. dirus. However, heavy mortality among infected An. stephensi in the present investigation indicates that the filaria vectorial capacity of the mosquito might be limited epidemiologically. The relationship between filaria vector competence and mosquito foregut armature is discussed. It was observed that the relative vector competence of the three anopheline species tested was in the same order as their relative degrees of armature elaboration. The converse would be expected if foregut armatures really give partial protection to the mosquitoes against filarial infection. It is suggested that high host microfilariae density favours larval survival proportional to the degree of armature development in Anopheles (Cellia) species.
A longitudinal study was conducted on the prevalence of Anopheles in three malaria endemic villages in Sekong province, in the southern region of Lao PDR, from August 2000 to October 2001. All night, human landing collections took place in August and October 2000 and April and October 2001, and blood smears were taken for malaria parasites during the same period. Mosquitoes were tested for sporozoite antigen using enzyme-linked immunosorbent assay. In August 2000 (wet season) and April 2001 (dry season) the ovaries of the mosquitoes were examined for parity. A total of 16 species of Anopheles were caught in the study sites of which An. dirus A, An. maculatus sl and An. jeyporiensis were positive for sporozoites. The entomological inoculation rate (EIR) ranged from 0.06 to 0.25. There was a good correlation between EIR and vectorial capacity in the wet season, especially in Pai Mai where the prevalence of malaria was also high during the wet seasons (11.8 and 10.53). An. dirus A showed ambivalence in their choice of feeding as approximately 50% attacked man indoors and an equal proportion outdoors. An dirus A was the main vector in Pai Mai. The parous rate did not significantly differ between the wet and dry season, although it was higher in the dry season. In Takaio the parasite prevalence ranged from 8.7% (dry season) to 37.1% (wet season) and An. jeyporiensis was the vector, and the risk of infection was 0.85 in the dry season while 0.99 in the wet season. In Toumgno An. maculatus sl was the vector and infection was found only in August and October 2000. However, malaria prevalence ranged from 9.69 to 20.4% and was equally high in the dry season. Cattle were also present close to the houses in all the villages and this might be a contributory factor in the prevalence of malaria.
Homalomena galbana Baharuddin S. & P.C. Boyce is described from the Maliau Basin Conservation Area, Sabah, representing the first species of the Homalomena Supergroup to be recorded from Sabah, and the first mesophytic species of the Supergroup to be described from Borneo. The species is illustrated and a brief discussion on the pollination role of interpistillar staminodes is presented.
The pupae of Desmometopa sp. (Diptera: Milichiidae) were collected from a human corpse found indoor in active decay stage together with the larvae of Sarcophagidae, Synthesiomyia nudiseta (Wulp), Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart). This research note is the first report of the Desmometopa sp. recovered from a human corpse in Malaysia.
The in vitro susceptibility of clinical Candida isolates towards fluconazole and voriconazole was determined using the E-test method. A total of 41 clinical isolates recovered from patients since 2004 until 2009 from two local hospitals in Kuala Lumpur, Malaysia were used. These comprised Candida tropicalis, Candida albicans, Candida krusei, Candida parapsilosis, Candida rugosa, Candida dubliniensis and Candida glabrata. Strains from American Type Culture Collection were used as quality control. Lawn cultures of the isolates on RPMI-1640 agar medium supplemented with 2% glucose were incubated with the E-test strips at 35ºC for 48 h. Our results show that 71% were susceptible to fluconazole and 90% were susceptible to voriconazole. All strains of C. krusei were resistant to fluconazole and 50% were susceptible in a dose-dependent manner to voriconazole. There were 66% and 33% of C. glabrata that were resistant to fluconazole and voriconazole. Our study revealed that majority of the clinical Candida isolates was susceptible to fluconazole and voriconazole with a small percentage being resistant to both the drugs.
Nine species of mosquitoes in eight genera are recorded for the first time in Singapore. An additional two species were overlooked in a 1986 checklist for mosquitoes in Singapore, and one was described after 1986. Location and habitat data are provided for the nine new records. With the inclusion of these new records the number of species reported from Singapore is 137.
Hypopygiopsis violacea, a species of fly of forensic importance, was recovered from a corpse and described for the first time. The morphological structures of the second and third instar larvae of four specimens were examined using light microscope. Observations were focused on three main morphological characters: cephalopharyngeal skeleton, anterior and posterior spiracles. Cephalopharyngeal skeleton of second instar larva is darkly pigmented and without accessory sclerite below the mouth hook. The anterior spiracles of second and third instar larvae have 8-9 papillae each, arranged in a single row. The posterior spiracle of second instar larva has two spiracular slits with no thickening of peritreme. This differentiates it from the third instar, whereby the latter has three slits for each posterior spiracle. Cephalopharyngeal skeleton of third instar larva is heavily pigmented. An accessory sclerite is found below the hook part of third instar larva but is absent in second instar. Peritreme of the posterior spiracle of third instar larva is thick almost complete encircling a button. The intersegmental spines of the cuticular surface are dome-shaped and unicuspid. Third instar larva of this species is large with size approximately 15 mm long. These findings provide important identification features of immature stages of Hy. violacea which could be useful in forensic entomology.
Rodents were collected from five wet markets (Chow Kit, Dato Keramat, Setapak, Jinjang and Kepong) in Kuala Lumpur, Federal Territory between March to April 2006. Ninety seven rats were trapped using wire traps measuring 29 x 22 x 50 cm baited with fruits, coconuts, dried fish or sweet potatoes. A total of 17 different species of parasites were identified from three species of rats out of which 11 (65%) were identified to be zoonotic. The helminths identified from the urban rats were nematodes- Capillaria hepatica, Gongylonema neoplasticum, Heterakis spumosa, Heterakis sp., Masterphorus muris, Nippostrongylus brasiliensis, Physolaptera sp., Pterogodermatis sp., Rictularia tani and Syphacia muris; cestodes- Hymenolepis nana, Hymenolepis diminuta, Hymenolepis sabnema, Hymenolepis sp., Raillietina sp. and Taenia taeniaeformis, and acanthocephalan- Moniliformis moniliformis. The following parasites are of potential medical importance: C. hepatica, G. neoplasticum, R. tani, S. muris, H. diminuta, H. nana, Raillietina sp. and T. taeniaeformis.
This study was carried out in an oil palm plantation in Bandar Baharu, Kedah using monkey carcasses and focuses in documenting the decomposition and dipteran colonization sequences in 50 days. This is the first study of Diptera associated with the exploitation of carcasses conducted in the north of peninsular Malaysia during the dry and wet seasons thereat. During the process of decomposition in both seasons, five phases of decay were recognized namely fresh, bloated, active decay, advance decay and dry remain. In this decomposition study, biomass loss of carcass occurred rapidly during the fresh to active decay stage due to the colonization and feeding activity of the Diptera larvae. The duration of the fresh and bloated stages of decay were the same in wet and dry seasons but later stages of decay were markedly shorter during the wet season. Twenty one species of adult Diptera were identified colonizing carcasses in the study period. Among the flies from the family Calliphoridae, Chrysomya megacephala Fabricius and Chrysomya nigripes Aubertin were recognized as the earliest arrivals on the first day of exposure. Adult Ch. nigripes was abundant for approximately two weeks after placement of the carcasses. By comparing the percentages of adults collected during the study period, the calliphorids abundance in percentages in wet season was 50.83%, but in dry season, the abundance was only about 35.2%. In contrast, the percentage of Sphaeroceridae in wet season was only 3.33%, but in the dry season, the abundance was 20.8%. Dipteran in family Phoridae, Piophilidae, Sepsidae, Drosophilidae and Dolichopodidae colonized the carcasses for a long period of time and were categorized as long term colonizers.
The mitochondiral DNA region encompassing the cytochrome oxidase subunit I (COI) and cytochrome oxidase subunit II (COII) genes of two Malaysian blow fly species, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) were studied. This region, which spans 2303bp and includes the COI, tRNA leucine and partial COII was sequenced from adult fly and larval specimens, and compared. Intraspecific variations were observed at 0.26% for Ch. megacephala and 0.17% for Ch. rufifacies, while sequence divergence between the two species was recorded at a minimum of 141 out of 2303 sites (6.12%). Results obtained in this study are comparable to published data, and thus support the use of DNA sequence to facilitate and complement morphology-based species identification.
An observational study was conducted in an oil palm plantation in Tanjung Sepat, Selangor, Malaysia on August until September 2007 to note the decomposition process of pigs and their related faunal succession. We collected six species of ants (Formicidae) from 3 subfamilies: Formicinae (Oecophylla smaragdina and Anoplolepis gracilipes), Myrmicinae (Tetramorium sp. and Pheidologeton sp.) and Ponerinae (Odontoponera sp. and Diacamma sp.) that were associated with pig carcasses placed on the ground. Oecophylla smaragdina, Pheidologeton sp. and Tetramorium sp. were found on a partially burnt pig carcass whereas the other species were recovered from unburned pig carcass. These ants predated on fly eggs, larvae, pupae and adults. Ants could be found at all stages of decomposition starting from fresh until dry stage. Predatory ants can reduce fly population and thus may affect the rate of carcass decomposition but this was not seen in our study. Even though O. smaragdina was seen at all stages of decomposition of the burnt pig, this did not alter much the decomposition process by fly larvae.
The natural and artificial mating of laboratory bred Aedes albopictus and transgenic Aedes aegypti RIDL-513A-Malaysian strain was conducted. The experiment consisted of crossmating of homologous Ae. aegypti RIDL female symbol X Ae. aegypti RIDL male symbol and reciprocal Ae. aegypti RIDL female symbol X Ae. albopictus WT male symbol. The other set comprised homologous Ae. albopictus WT female symbol X Ae. albopictus WT male symbol and reciprocal Ae. albopictus WT female symbol X Ae. aegypti RIDL male symbol. This study demonstrated that reproductive barriers exist between these two species. Cross insemination occurred between A. albopictus male and Ae. aegypti female and their reciprocals. There was 26.67% and 33.33% insemination rate in Ae. aegypti RIDL female cross-mating with A. albopictus WT male and Ae. albopictus female cross-mating with Ae. aegypti RIDL male, respectively. There was 0% hatchability in both directions of the reciprocals. There was also no embryonation of these eggs which were bleached. Although none of the female Ae. albopictus WT was inseminated in the cross-mating with Ae. albopictus WT female symbol X Ae. aegypti RIDL male symbol, a total of 573 eggs were obtained. The homologous mating was very productive resulting in both high insemination rate and hatchability rates. Generally there was a significantly higher insemination rate with artificial mating insemination of homologous than with artificial mating of reciprocal crosses. Interspecific mating between Ae. aegypti RIDL and Ae. albopictus wild type was not productive and no hybrid was obtained, indicating absence of horizontal transfer of introduced RIDL gene in Ae. aegypti to Ae. albopictus.
This preliminary study was carried out in a palm oil plantation in Tanjung Sepat, Selangor in 17 May 2007 by using pig (Sus scrofa) as a carcass model in forensic entomological research. A 3 month old pig (8.5 kg) that died of pneumonio was placed in the field to observe the decomposition stages and the fauna succession of forensically important flies. Observation was made for two weeks; two visits per day and all climatological data were recorded. The first visitor to the pig carcass was a muscid fly, seen within a minute, and followed by ants and spiders. Within half an hour, calliphorid flies came over. On the second day (fresh), few calliphorid and sarcophagid flies were found on the carcass. Two different species of moths were trapped in the hanging net. The first larva mass occurred on the third day (bloated) around the mouthpart, with some L1 and L2 found in the eyes. Reduvid bugs and Staphylinidae beetles were recovered on the fourth day (active decay), and new maggot masses occurred in the eyes and anus. L3 larvae could be found beneath the pig carcass on the fourth day. On the fifth day (active decay), new maggot masses were found on neck, thorax, and hind legs. Advance decay occurred on the sixth day with abundant maggots covering all over the body. The main adult fly population was Chrysomya megacephala (day 2 to day 6), but the larvae population was mainly those of Chrysomya rufifacies (day 4 to day 14). The dry stage began on the eighth day. Hermetia illucens adult was caught on day-13, and a larvae mass of Chrysomya rufifacies was seen burrowing under the soil. This forensic entomological research using pig carcass model was the first record in this country.