Displaying publications 61 - 73 of 73 in total

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  1. Identification of lactic acid bacteria from chili bo, a Malaysian food ingredient
    Leisner JJ, Pot B, Christensen H, Rusul G, Olsen JE, Wee BW, et al.
    Appl Environ Microbiol, 1999 Feb;65(2):599-605.
    PMID: 9925588
    Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28 degreesC with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg-1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.
    Matched MeSH terms: Genes, rRNA
  2. Myxozoan infection of the Malaysian mahseer, Tor tambroides, of Tasik Kenyir Reservoir, Malaysia: description of a new species Myxobolus tambroides sp.n
    Székely C, Shaharom F, Cech G, Mohamed K, Zin NA, Borkhanuddin MH, et al.
    Parasitol Res, 2012 Oct;111(4):1749-56.
    PMID: 22782473
    Tor tambroides, a common and appreciated cyprinid fish of the Tasik Kenyir water reservoir in Malaysia, is one of the species selected for propagation. This fish was first successfully propagated in Malaysia by the Department of Agriculture, Sarawak, Malaysia, and the breeding program continued throughout the country. The gills were frequently infected by a Myxobolus species to be described as Myxobolus tambroides sp. n. The small, 50 to 70 μm, round plasmodia of this species is located intralamellarly. Plasmodia were filled with pyriform myxospores, 9.9 and 7.4 μm wide. In sutural view, the caudal end of the myxospores had a distinctive valvular groove, parallel with the suture. Plasmodia caused deformations on the affected and the neighbouring gill lamellae. The 18S rDNA sequence of M. tambroides sp.n. did not show a close relationship with any other Myxobolus spp., represented in the GenBank. This might be an emerging parasite likely to impact the propagation of this fish.
    Matched MeSH terms: Genes, rRNA
  3. Fulltext Myxosporean hyperparasites of gill monogeneans are basal to the multivalvulida
    Freeman MA, Shinn AP
    Parasit Vectors, 2011;4:220.
    PMID: 22115202 DOI: 10.1186/1756-3305-4-220
    Myxosporeans are known from aquatic annelids but parasitism of platyhelminths by myxosporeans has not been widely reported. Hyperparasitism of gill monogeneans by Myxidium giardi has been reported from the European eel and Myxidium-like hyperparasites have also been observed during studies of gill monogeneans from Malaysia and Japan.The present study aimed to collect new hyperparasite material from Malaysia for morphological and molecular descriptions. In addition, PCR screening of host fish was undertaken to determine whether they are also hosts for the myxosporean.
    Matched MeSH terms: Genes, rRNA
  4. Fulltext Molecular identification and transmission studies of X-cell parasites from Atlantic cod Gadus morhua (Gadiformes: Gadidae) and the northern black flounder Pseudopleuronectes obscurus (Pleuronectiformes: Pleuronectidae)
    Freeman MA, Eydal M, Yoshimizu M, Watanabe K, Shinn AP, Miura K, et al.
    Parasit Vectors, 2011;4:15.
    PMID: 21299903 DOI: 10.1186/1756-3305-4-15
    Epidermal pseudotumours from Hippoglossoides dubius and Acanthogobius flavimanus in Japan and gill lesions in Limanda limanda from the UK have been shown to be caused by phylogenetically related protozoan parasites, known collectively as X-cells. However, the phylogenetic position of the X-cell group is not well supported within any of the existing protozoan phyla and they are currently thought to be members of the Alveolata.Ultrastructural features of X-cells in fish pseudotumours are somewhat limited and no typical environmental stages, such as spores or flagellated cells, have been observed. The life cycles for these parasites have not been demonstrated and it remains unknown how transmission to a new host occurs. In the present study, pseudobranchial pseudotumours from Atlantic cod, Gadus morhua, in Iceland and epidermal pseudotumours from the northern black flounder, Pseudopleuronectes obscurus, in Japan were used in experimental transmission studies to establish whether direct transmission of the parasite is achievable. In addition, X-cells from Atlantic cod were sequenced to confirm whether they are phylogenetically related to other X-cells and epidermal pseudotumours from the northern black flounder were analysed to establish whether the same parasite is responsible for infecting different flatfish species in Japan.
    Matched MeSH terms: Genes, rRNA
  5. Detection and molecular characterization of Giardia isolated from recreational lake water in Malaysia
    Lim YA, Ramasame SD, Mahdy MA, Sulaiman WY, Smith HV
    Parasitol Res, 2009 Dec;106(1):289-91.
    PMID: 19705155 DOI: 10.1007/s00436-009-1602-y
    Nine 50-l surface water samples from a Malaysian recreational lake were examined microscopically using an immunomagnetisable separation-immunofluorescent method. No Cryptosporidium oocysts were detected, but 77.8% of samples contained low numbers of Giardia cysts (range, 0.17-1.1 cysts/l), which were genetically characterised by SSU rRNA gene sequencing. Genotype analyses indicated the presence of Giardia duodenalis assemblage A suggesting potential risk to public health. The present study represents the first contribution to our knowledge of G. duodenalis assemblages in Malaysian recreational water.
    Matched MeSH terms: Genes, rRNA
  6. Tropical soil bacterial communities in Malaysia: pH dominates in the equatorial tropics too
    Tripathi BM, Kim M, Singh D, Lee-Cruz L, Lai-Hoe A, Ainuddin AN, et al.
    Microb Ecol, 2012 Aug;64(2):474-84.
    PMID: 22395784 DOI: 10.1007/s00248-012-0028-8
    The dominant factors controlling soil bacterial community variation within the tropics are poorly known. We sampled soils across a range of land use types--primary (unlogged) and logged forests and crop and pasture lands in Malaysia. PCR-amplified soil DNA for the bacterial 16S rRNA gene targeting the V1-V3 region was pyrosequenced using the 454 Roche machine. We found that land use in itself has a weak but significant effect on the bacterial community composition. However, bacterial community composition and diversity was strongly correlated with soil properties, especially soil pH, total carbon, and C/N ratio. Soil pH was the best predictor of bacterial community composition and diversity across the various land use types, with the highest diversity close to neutral pH values. In addition, variation in phylogenetic structure of dominant lineages (Alphaproteobacteria, Beta/Gammaproteobacteria, Acidobacteria, and Actinobacteria) is also significantly correlated with soil pH. Together, these results confirm the importance of soil pH in structuring soil bacterial communities in Southeast Asia. Our results also suggest that unlike the general diversity pattern found for larger organisms, primary tropical forest is no richer in operational taxonomic units of soil bacteria than logged forest, and agricultural land (crop and pasture) is actually richer than primary forest, partly due to selection of more fertile soils that have higher pH for agriculture and the effects of soil liming raising pH.
    Matched MeSH terms: Genes, rRNA
  7. Distinctive bacterial communities in the rhizoplane of four tropical tree species
    Oh YM, Kim M, Lee-Cruz L, Lai-Hoe A, Go R, Ainuddin N, et al.
    Microb Ecol, 2012 Nov;64(4):1018-27.
    PMID: 22767122 DOI: 10.1007/s00248-012-0082-2
    It is known that the microbial community of the rhizosphere is not only influenced by factors such as root exudates, phenology, and nutrient uptake but also by the plant species. However, studies of bacterial communities associated with tropical rainforest tree root surfaces, or rhizoplane, are lacking. Here, we analyzed the bacterial community of root surfaces of four species of native trees, Agathis borneensis, Dipterocarpus kerrii, Dyera costulata, and Gnetum gnemon, and nearby bulk soils, in a rainforest arboretum in Malaysia, using 454 pyrosequencing of the 16S rRNA gene. The rhizoplane bacterial communities for each of the four tree species sampled clustered separately from one another on an ordination, suggesting that these assemblages are linked to chemical and biological characteristics of the host or possibly to the mycorrhizal fungi present. Bacterial communities of the rhizoplane had various similarities to surrounding bulk soils. Acidobacteria, Alphaproteobacteria, and Betaproteobacteria were dominant in rhizoplane communities and in bulk soils from the same depth (0-10 cm). In contrast, the relative abundance of certain bacterial lineages on the rhizoplane was different from that in bulk soils: Bacteroidetes and Betaproteobacteria, which are known as copiotrophs, were much more abundant in the rhizoplane in comparison to bulk soil. At the genus level, Burkholderia, Acidobacterium, Dyella, and Edaphobacter were more abundant in the rhizoplane. Burkholderia, which are known as both pathogens and mutualists of plants, were especially abundant on the rhizoplane of all tree species sampled. The Burkholderia species present included known mutualists of tropical crops and also known N fixers. The host-specific character of tropical tree rhizoplane bacterial communities may have implications for understanding nutrient cycling, recruitment, and structuring of tree species diversity in tropical forests. Such understanding may prove to be useful in both tropical forestry and conservation.
    Matched MeSH terms: Genes, rRNA
  8. Fulltext Isolation and characterization of Acanthamoeba spp. from air-conditioners in Kuala Lumpur, Malaysia
    Chan LL, Mak JW, Low YT, Koh TT, Ithoi I, Mohamed SM
    Acta Trop, 2011 Jan;117(1):23-30.
    PMID: 20858455 DOI: 10.1016/j.actatropica.2010.09.004
    During a study on the quality of the indoor environment, Acanthamoeba spp. were detected in 20 out of 87 dust samples collected from air-conditioners installed in a four-story campus building located in Kuala Lumpur, Malaysia. Twenty-one cloned Acanthamoeba isolates designated as IMU1 to IMU21 were established from the positive primary cultures. Five species were identified from the 16 isolates according to the morphological criteria of Pussard and Pons; i.e. A. castellanii, A. culbertsoni, A. griffini, A. hatchetti and A. polyphaga. Species identities for the remaining five isolates (IMU4, IMU5, IMU15, IMU20 and IMU21), however, could not be determined morphologically. At genotypic characterization, these isolates were placed into T3 (IMU14); T5 (IMU16 and IMU17) and T4 (all the remaining isolates). To predict the potential pathogenicity of these Acanthamoeba isolates, thermo- and osmotolerance tests were employed; many isolates were predicted as potential human pathogens based on the outcome of these tests. This is the first time potentially pathogenic Acanthamoeba have been isolated from air-conditioners in Malaysia.
    Matched MeSH terms: Genes, rRNA
  9. Fulltext High prevalence of muscular sarcocystosis in cattle and water buffaloes from Selangor, Malaysia
    Latif B, Vellayan S, Heo CC, Kannan Kutty M, Omar E, Abdullah S, et al.
    Trop Biomed, 2013 Dec;30(4):699-705.
    PMID: 24522140 MyJurnal
    The prevalence of sarcocystosis in cattle and water buffaloes from peninsular Malaysia was investigated in abattoirs in Selangor state, February, 2011, to March, 2012. Fresh muscle samples were collected from the tongue, heart, oesophagus, diaphragm and skeletal muscles of 102 cattle and 18 water buffaloes. Each sample was initially screened by light microscopy and then fixed for further histopathological analysis. Out of 120 animals examined, 49 (40.8%) harboured the microscopic type of Sarcocystis spp. The positivity rate for cattle was 36.2% and for water buffaloes 66.7%. In cattle, the organs highly infected were the skeletal muscles and diaphragm (27% each), followed by tongue and esophagus (24.3% each), and the heart (8%). In water buffaloes, the heart was most often infected (66.7%), followed by the oesophagus (50%) and skeletal muscle (33.3%); no sarcocysts were detected in the tongue and diaphragm. The shape of the sarcocyst was fusiform to oval with a mean cyst size of 151.66 x 75.83 μm and wall thickness of 2.47 μm in cattle, and 114 x 50.81 μm cyst size and the wall thickness of 1.11 μm in water buffaloes, consistent with Sarcocystis cruzi and Sarcocystis levinei, respectively. Remaining tissue from cattle was subjected to parasite specific 18S rRNA gene PCR and Sarcocystis cruzi was confirmed, at least exemplarily. The peripheral metrocytes and the banana-shaped bradyzoites (15.23 x 2.2 μm in cattle and 11.49 x 2.45 μm in water buffalo hosts) were easily recognized. In conclusion, a high positivity rate was found in Malaysian meat-producing animals with possible implications for meat consumption and human health.
    Matched MeSH terms: Genes, rRNA
  10. Leuconostoc durionis sp. nov., a heterofermenter with no detectable gas production from glucose
    Leisner JJ, Vancanneyt M, Van der Meulen R, Lefebvre K, Engelbeen K, Hoste B, et al.
    Int J Syst Evol Microbiol, 2005 May;55(Pt 3):1267-1270.
    PMID: 15879266 DOI: 10.1099/ijs.0.63434-0
    Three lactic acid bacterial (LAB) strains obtained from a Malaysian acid-fermented condiment, tempoyak (made from pulp of the durian fruit), showed analogous but distinct patterns after screening by SDS-PAGE of whole-cell proteins and comparison with profiles of all recognized LAB species. 16S rRNA gene sequencing of one representative strain showed that the taxon belongs phylogenetically to the genus Leuconostoc, with its nearest neighbour being Leuconostoc fructosum (98 % sequence similarity). Biochemical characteristics and DNA-DNA hybridization experiments demonstrated that the strains differ from Leuconostoc fructosum and represent a single, novel Leuconostoc species for which the name Leuconostoc durionis sp. nov. is proposed. The type strain is LMG 22556(T) (= LAB 1679(T) = D-24(T) = CCUG 49949(T)).
    Matched MeSH terms: Genes, rRNA
  11. Amycolatopsis saalfeldensis sp. nov., a novel actinomycete isolated from a medieval alum slate mine
    Carlsohn MR, Groth I, Tan GYA, Schütze B, Saluz HP, Munder T, et al.
    Int J Syst Evol Microbiol, 2007 Jul;57(Pt 7):1640-1646.
    PMID: 17625209 DOI: 10.1099/ijs.0.64903-0
    Three actinomycetes isolated from the surfaces of rocks in a medieval slate mine were examined in a polyphasic taxonomic study. Chemotaxonomic and morphological characteristics of the isolates were typical of strains of the genus Amycolatopsis. The isolates had identical 16S rRNA gene sequences and formed a distinct phyletic line towards the periphery of the Amycolatopsis mediterranei clade, being most closely related to Amycolatopsis rifamycinica. The organisms shared a wide range of genotypic and phenotypic markers that distinguished them from their closest phylogenetic neighbours. On the basis of these results, a novel species, Amycolatopsis saalfeldensis sp. nov., is proposed. The type strain is HKI 0457(T) (=DSM 44993(T)=NRRL B-24474(T)).
    Matched MeSH terms: Genes, rRNA
  12. Fulltext Phylogenetic analysis of simian Plasmodium spp. infecting Anopheles balabacensis Baisas in Sabah, Malaysia
    Chua TH, Manin BO, Daim S, Vythilingam I, Drakeley C
    PLoS Negl Trop Dis, 2017 Oct;11(10):e0005991.
    PMID: 28968395 DOI: 10.1371/journal.pntd.0005991
    BACKGROUND: Anopheles balabacensis of the Leucospyrus group has been confirmed as the primary knowlesi malaria vector in Sabah, Malaysian Borneo for some time now. Presently, knowlesi malaria is the only zoonotic simian malaria in Malaysia with a high prevalence recorded in the states of Sabah and Sarawak.

    METHODOLOGY/PRINCIPAL FINDINGS: Anopheles spp. were sampled using human landing catch (HLC) method at Paradason village in Kudat district of Sabah. The collected Anopheles were identified morphologically and then subjected to total DNA extraction and polymerase chain reaction (PCR) to detect Plasmodium parasites in the mosquitoes. Identification of Plasmodium spp. was confirmed by sequencing the SSU rRNA gene with species specific primers. MEGA4 software was then used to analyse the SSU rRNA sequences and bulid the phylogenetic tree for inferring the relationship between simian malaria parasites in Sabah. PCR results showed that only 1.61% (23/1,425) of the screened An. balabacensis were infected with one or two of the five simian Plasmodium spp. found in Sabah, viz. Plasmodium coatneyi, P. inui, P. fieldi, P. cynomolgi and P. knowlesi. Sequence analysis of SSU rRNA of Plasmodium isolates showed high percentage of identity within the same Plasmodium sp. group. The phylogenetic tree based on the consensus sequences of P. knowlesi showed 99.7%-100.0% nucleotide identity among the isolates from An. balabacensis, human patients and a long-tailed macaque from the same locality.

    CONCLUSIONS/SIGNIFICANCE: This is the first study showing high molecular identity between the P. knowlesi isolates from An. balabacensis, human patients and a long-tailed macaque in Sabah. The other common simian Plasmodium spp. found in long-tailed macaques and also detected in An. balabacensis were P. coatneyi, P. inui, P. fieldi and P. cynomolgi. The high percentage identity of nucleotide sequences between the P. knowlesi isolates from the long-tailed macaque, An. balabacensis and human patients suggests a close genetic relationship between the parasites from these hosts.

    Matched MeSH terms: Genes, rRNA
  13. Diversity of bovine rumen methanogens In vitro in the presence of condensed tannins, as determined by sequence analysis of 16S rRNA gene library
    Tan HY, Sieo CC, Lee CM, Abdullah N, Liang JB, Ho YW
    J Microbiol, 2011 Jun;49(3):492-8.
    PMID: 21717338 DOI: 10.1007/s12275-011-0319-7
    Molecular diversity of rumen archaeal populations from bovine rumen fluid incubated with or without condensed tannins was investigated using 16S rRNA gene libraries. The predominant order of rumen archaea in the 16S rRNA gene libraries of the control and condensed tannins treatment was found to belong to a novel group of rumen archaea that is distantly related to the order Thermoplasmatales, with 59.5% (15 phylotypes) and 81.43% (21 phylotypes) of the total clones from the control and treatment clone libraries, respectively. The 16S rRNA gene library of the control was found to have higher proportions of methanogens from the orders Methanomicrobiales (32%) and Methanobacteriales (8.5%) as compared to those found in the condensed tannins treatment clone library in both orders (16.88% and 1.68% respectively). The phylotype distributed in the order Methanosarcinales was only found in the control clone library. The study indicated that condensed tannins could alter the diversity of bovine rumen methanogens.
    Matched MeSH terms: Genes, rRNA
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