Displaying publications 1 - 20 of 55 in total

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  1. Gan HM, Sieo CC, Tang SG, Omar AR, Ho YW
    Virol J, 2013;10:308.
    PMID: 24134834 DOI: 10.1186/1743-422X-10-308
    Bacteriophage EC1-UPM is an N4-like bacteriophage which specifically infects Escherichia coli O78:K80, an avian pathogenic strain that causes colibacillosis in poultry. The complete genome sequence of bacteriophage EC1-UPM was analysed and compared with other closely related N4-like phage groups to assess their genetic similarities and differences.
  2. Shokryazdan P, Faseleh Jahromi M, Liang JB, Kalavathy R, Sieo CC, Ho YW
    PLoS One, 2016;11(7):e0159851.
    PMID: 27467068 DOI: 10.1371/journal.pone.0159851
    Two previously isolated Lactobacillus strains (L. fermentum HM3 from human milk and L. buchneri FD2 from fermented dates), intended as probiotic for human, were assessed for their safety using acute and subacute oral toxicity tests in rats. In addition, their effects on cecal microflora and harmful bacterial enzymes (β-glucuronidase and β-glucosidase) of the tested animals were also determined. The results showed that L. buchneri FD2, L. fermentum HM3, or a mixture of them were safe up to a level of 1010 CFU/kg BW/day in a 14-day or 28-day treatment period. Both strains were well tolerated and there were no observed adverse effects on growth, feed consumption, cellular blood components and vital organs of the treated animals. The Lactobacillus strains were also able to reduce harmful intestinal bacterial enzymes, and decrease pathogenic bacterial populations while increasing beneficial bacterial populations. These results suggest that the two Lactobacillus strains are safe and could be potential probiotic for human.
  3. Huang XD, Liang JB, Tan HY, Yahya R, Long R, Ho YW
    J Agric Food Chem, 2011 Oct 12;59(19):10677-82.
    PMID: 21899359 DOI: 10.1021/jf201925g
    Depending on their source, concentration, chemical structure, and molecular weight, condensed tannins (CTs) form insoluble complexes with protein, which could lead to ruminal bypass protein, benefiting animal production. In this study, CTs from Leuceana leucocephala hybrid were fractionated into five fractions by a size exclusion chromatography procedure. The molecular weights of the CT fractions were determined using Q-TOF LC-MS, and the protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay with bovine serum albumin (BSA) as the standard protein. The calculated number-average molecular weights (M(n)) were 1348.6, 857.1, 730.1, 726.0, and 497.1, and b values (the b value represents the CT quantity that is needed to bind half of the maximum precipitable BSA) of the different molecular weight fractions were 0.381, 0.510, 0.580, 0.636, and 0.780 for fractions 1, 2, 3, 4, and 5, respectively. The results indicated that, in general, CTs of higher molecular weight fractions have stronger protein-binding affinity than those of lower molecular weights. However, the number of hydroxyl units within the structure of CT polymers also affects the protein-binding affinity.
  4. Shokryazdan P, Faseleh Jahromi M, Liang JB, Ho YW
    J Am Coll Nutr, 2017 09 22;36(8):666-676.
    PMID: 28937854 DOI: 10.1080/07315724.2017.1337529
    Probiotics have become highly recognized as supplements for humans and animals because of their beneficial effects on health and well-being. The present review aims to provide an overview of different steps through which microbial strains become applicable probiotics in food and/or feed industries. Isolation of potential probiotic strains is the first step. Lactic acid bacteria are the most frequently used microorganisms as probiotics, which can be isolated from human, animal, plant, and environment. The next steps are identification of the isolates and characterization of them based on the main selection criteria for any potential probiotic microorganism, including resistance to gastric acidity and bile salt, adherence to mucus and/or intestinal epithelial cells and cell lines, and antimicrobial and antagonism activity against potentially pathogenic microbes. There are additional probiotic properties that may be considered for selection of probiotic strains with specific effects, such as cholesterol reduction ability, antioxidant activity, or cytotoxic effect against cancer cells. However, a potential probiotic does not need to fulfill all such selection criteria. As the last step, safety status of probiotics for humans is verified by taxonomy clarification, in vitro and in vivo tests, human trials, and genome sequencing.
  5. Shokryazdan P, Sieo CC, Kalavathy R, Liang JB, Alitheen NB, Faseleh Jahromi M, et al.
    Biomed Res Int, 2014;2014:927268.
    PMID: 25105147 DOI: 10.1155/2014/927268
    The objective of this study was to isolate, identify, and characterize some lactic acid bacterial strains from human milk, infant feces, and fermented grapes and dates, as potential probiotics with antimicrobial activity against some human pathogenic strains. One hundred and forty bacterial strains were isolated and, after initial identification and a preliminary screening for acid and bile tolerance, nine of the best isolates were selected and further identified using 16 S rRNA gene sequences. The nine selected isolates were then characterized in vitro for their probiotic characteristics and their antimicrobial activities against some human pathogens. Results showed that all nine isolates belonged to the genus Lactobacillus. They were able to tolerate pH 3 for 3 h, 0.3% bile salts for 4 h, and 1.9 mg/mL pancreatic enzymes for 3 h. They exhibited good ability to attach to intestinal epithelial cells and were not resistant to the tested antibiotics. They also showed good antimicrobial activities against the tested pathogenic strains of humans, and most of them exhibited stronger antimicrobial activity than the reference strain L. casei Shirota. Thus, the nine Lactobacillus strains could be considered as potential antimicrobial probiotic strains against human pathogens and should be further studied for their human health benefits.
  6. Saminathan M, Tan HY, Sieo CC, Abdullah N, Wong CM, Abdulmalek E, et al.
    Molecules, 2014 Jun 12;19(6):7990-8010.
    PMID: 24927368 DOI: 10.3390/molecules19067990
    Condensed tannins (CTs) form insoluble complexes with proteins and are able to protect them from degradation, which could lead to rumen bypass proteins. Depending on their degrees of polymerization (DP) and molecular weights, CT fractions vary in their capability to bind proteins. In this study, purified condensed tannins (CTs) from a Leucaena leucocephala hybrid were fractionated into five different molecular weight fractions. The structures of the CT fractions were investigated using 13C-NMR. The DP of the CT fractions were determined using a modified vanillin assay and their molecular weights were determined using Q-TOF LC-MS. The protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay. The DP of the five CT fractions (fractions F1-F5) measured by the vanillin assay in acetic acid ranged from 4.86 to 1.56. The 13C-NMR results showed that the CT fractions possessed monomer unit structural heterogeneity. The number-average molecular weights (Mn) of the different fractions were 1265.8, 1028.6, 652.2, 562.2, and 469.6 for fractions F1, F2, F3, F4, and F5, respectively. The b values representing the CT quantities needed to bind half of the maximum precipitable bovine serum albumin increased with decreasing molecular weight--from fraction F1 to fraction F5 with values of 0.216, 0.295, 0.359, 0.425, and 0.460, respectively. This indicated that higher molecular weight fractions of CTs from L. leucocephala have higher protein-binding affinities than those with lower molecular weights.
  7. Tang SGH, Sieo CC, Ramasamy K, Saad WZ, Wong HK, Ho YW
    BMC Vet Res, 2017 Aug 17;13(1):248.
    PMID: 28814309 DOI: 10.1186/s12917-017-1160-y
    BACKGROUND: The increasing trend of ban on the use of antibiotic growth promoters (AGPs) across the globe in the poultry industry has led to a growing need for alternatives to AGPs. Prebiotic, probiotic and their combination as a synbiotic have been considered as potential alternatives. This study aimed to investigate the effects of a prebiotic (isomaltooligosaccharide, IMO), a probiotic (PrimaLac®), and their combination (synbiotic) on hen performance, biochemical and haematological responses, and relative organ weights from 20 to 52 weeks of age.

    RESULTS: Supplementation of 1% IMO (PRE), 0.1% PrimaLac® (PRO) and 1% IMO + 0.1% PrimaLac® (SYN) improved (P 

  8. Liew SL, Ariff AB, Raha AR, Ho YW
    Int J Food Microbiol, 2005 Jul 15;102(2):137-42.
    PMID: 15992613
    This study was undertaken to optimize yeast extract, glucose, and vitamin concentrations; and also culture pH for maximizing the growth of a probiotic bacterium, Lactobacillus rhamnosus, and to assess the effects of these factors by using response surface methodology. A central composite design was used as an experimental design for the allocation of treatment combinations. A polynomial regression model with cubic and quartic terms was used for analysis of the experimental data. It was found that the effects involving yeast extract, glucose, vitamins and pH on the growth of L. rhamnosus were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors for the growth of L. rhamnosus are as follows: pH=6.9; vitamin solution=1.28% (v/v); glucose=5.01% (w/v) and yeast extract=6.0% (w/v).
  9. Jin LZ, Ho YW, Abdullah N, Ali MA, Jalaludin S
    J Appl Microbiol, 1998 Jun;84(6):1171-4.
    PMID: 9717304
    Two Lactobacillus isolates, Lact. acidophilus I 26 and Lact. fermentum I 25, were selected, based on their poor aggregation with Escherichia coli and strong ability to adhere to ileal epithelial cells (IEC), to study in vitro interactions with E. coli O1:K1, O2:K1 and O78:K80 in an IEC radioactive-assay under the conditions of exclusion (lactobacilli and IEC, followed by the addition of E. coli), competition (lactobacilli, IEC and E. coli together) and displacement (E. coli and IEC, followed by the addition of lactobacilli). The results indicated that Lact. acidophilus I 26 and Lact. fermentum I 25 could not significantly reduce the attachment of E. coli O1:K1, O2:K1 and O78:K80 to IEC under the three conditions tested in vitro, except that the attachment of E. coli O1:K1 was slightly reduced by Lact. fermentum I 25 in the test for competition.
  10. Ho YW, Bauchop T
    J. Gen. Microbiol., 1991 Jan;137(1):213-7.
    PMID: 2045780
    Three polycentric rumen fungi, LL, LC2 and Ruminomyces elegans (C2), isolated from the rumen of cattle were grown in six culture media. LL and LC2 were morphologically similar. Their characteristics resembled those of Orpinomyces and Neocallimastix joyonii, and they grew well and produced sporangia after 3-4 d growth in all the media. R. elegans differed morphologically from LL and LC2, but although it also grew well in all media, abundant sporangia occurred only after 2-3 d growth in media containing cellulose. Undifferentiated sporangia were produced by all three isolates; differentiation of the sporangia did not occur in the spent growth media. However, if thalli possessing recently-formed sporangia were transferred to, or flooded with, fresh liquid medium or rumen fluid, zoosporogenesis and liberation of zoospores occurred within 17-20 min for isolates LL and LC2 and 30 min for R. elegans. Procedures for inducing zoosporogenesis by polycentric anaerobic fungi are described.
  11. Saminathan M, Sieo CC, Gan HM, Ravi S, Venkatachalam K, Abdullah N, et al.
    J Sci Food Agric, 2016 Oct;96(13):4565-74.
    PMID: 26910767 DOI: 10.1002/jsfa.7674
    BACKGROUND: Condensed tannin (CT) fractions of different molecular weights (MWs) may affect rumen microbial metabolism by altering bacterial diversity. In this study the effects of unfractionated CTs (F0) and five CT fractions (F1-F5) of different MWs (F1, 1265.8 Da; F2, 1028.6 Da; F3, 652.2 Da; F4, 562.2 Da; F5, 469.6 Da) from Leucaena leucocephala hybrid-Rendang (LLR) on the structure and diversity of the rumen bacterial community were investigated in vitro.

    RESULTS: Real-time polymerase chain reaction assay showed that the total bacterial population was not significantly (P > 0.05) different among the dietary treatments. Inclusion of higher-MW CT fractions F1 and F2 significantly (P 

  12. Lan GQ, Ho YW, Abdullah N
    Int J Syst Evol Microbiol, 2002 May;52(Pt 3):713-718.
    PMID: 12054230 DOI: 10.1099/00207713-52-3-713
    Five strains of phytase-producing, gram-negative, non-spore-forming, non-motile, small, stout, rod-shaped, strictly anaerobic, fermentative bacteria were isolated from the rumens of cattle in Malaysia. All five strains had morphological, physiological and biochemical features in common. Although these strains had many physiological and biochemical characteristics that were identical to those of the Mitsuokella multacida type strain (ATCC 27723T), they could be distinguished from this species by means of the following characteristics: a smaller cell size (1.2-2.4 microm long and 0.6-0.8 microm wide); a lower final pH value (3.8-4.0) in peptone/yeast extract/glucose broth; inhibition by 0.001% brilliant green; insensitivity to kanamycin (100 microg ml(-1)) and penicillin (10 microg ml(-1)); a higher optimum growth temperature (approx. 42 degrees C); the ability to grow at 45 and 47 degrees C; the ability to ferment glycerol, sorbitol and amidon; and the inability to ferment mannitol, rhamnose, D-tagatose and melezitose. The G+C content of the type strain (M 9T) of these five strains was 56.9 mol%. Analysis of the 16S rRNA gene sequence of type strain M 9T indicated that the strain falls within the genus Mitsuokella. The sequence similarity between type strain M 9T and Mitsuokella multacida was 98.7%. The DNA-DNA relatedness between type strain M 9T and Mitsuokella multacida type strain DSM 20544T (= ATCC 27723T) was 63.8%, indicating that, in spite of a high level of similarity for the 16S rRNA gene sequence, type strain M 9T is independent of Mitsuokella multacida at the species level. On the basis of these results, a new species, Mitsuokella jalaludinii sp. nov., is proposed for these strains. The type strain is M 9T (= DSM 13811T = ATCC BAA-307T).
  13. Koh KC, Islam M, Chan WK, Lee WY, Ho YW, Alsagoff SAH, et al.
    Med J Malaysia, 2017 08;72(4):209-214.
    PMID: 28889131
    INTRODUCTION: In Malaysia, the prevalence of missed opportunities for HIV-testing is unknown. Missed opportunities have been linked to late diagnosis of HIV and poorer outcome for patients. We describe missed opportunities for earlier HIV-testing in newly-HIV-diagnosed patients.

    METHODS: Cross sectional study. Adult patients diagnosed with HIV infection and had at least one medical encounter in a primary healthcare setting during three years prior to diagnosis were included. We collected data on sociodemographic characteristics, patient characteristics at diagnosis, HIV-related conditions and whether they were subjected to risk assessment and offered HIV testing during the three years prior to HIV diagnosis.

    RESULTS: 65 newly HIV-diagnosed patients (male: 92.3%; Malays: 52.4%; single: 66.7%; heterosexual: 41%; homosexual 24.6%; CD4 <350 at diagnosis: 63%). 93.8% were unaware of their HIV status at diagnosis. Up to 56.9% had presented with HIV-related conditions at a primary healthcare facility during the three years prior to diagnosis. Slightly more than half were had risk assessment done and only 33.8% were offered HIV-testing.

    CONCLUSIONS: Missed opportunities for HIV-testing was unacceptably high with insufficient risk assessment and offering of HIV-testing. Risk assessment must be promoted and primary care physicians must be trained to recognize HIV-related conditions that will prompt them to offer HIVtesting.

  14. Faseleh Jahromi M, Liang JB, Mohamad R, Goh YM, Shokryazdan P, Ho YW
    Biomed Res Int, 2013;2013:397934.
    PMID: 23484116 DOI: 10.1155/2013/397934
    The primary objective of this study was to test the hypothesis that solid state fermentation (SSF) of agro-biomass (using rice straw as model); besides, breaking down its lignocellulose content to improve its nutritive values also produces lovastatin which could be used to suppress methanogenesis in the rumen ecosystem. Fermented rice straw (FRS) containing lovastatin after fermentation with Aspergillus terreus was used as substrate for growth study of rumen microorganisms using in vitro gas production method. In the first experiment, the extract from the FRS (FRSE) which contained lovastatin was evaluated for its efficacy for reduction in methane (CH4) production, microbial population, and activity in the rumen fluid. FRSE reduced total gas and CH4 productions (P < 0.01). It also reduced (P < 0.01) total methanogens population and increased the cellulolytic bacteria including Ruminococcus albus, Fibrobacter succinogenes (P < 0.01), and Ruminococcus flavefaciens (P < 0.05). Similarly, FRS reduced total gas and CH4 productions, methanogens population, but increased in vitro dry mater digestibility compared to the non-fermented rice straw. Lovastatin in the FRSE and the FRS significantly increased the expression of HMG-CoA reductase gene that produces HMG-CoA reductase, a key enzyme for cell membrane production in methanogenic Archaea.
  15. Jahromi MF, Liang JB, Ho YW, Mohamad R, Goh YM, Shokryazdan P
    J Biomed Biotechnol, 2012;2012:196264.
    PMID: 23118499 DOI: 10.1155/2012/196264
    Ability of two strains of Aspergillus terreus (ATCC 74135 and ATCC 20542) for production of lovastatin in solid state fermentation (SSF) using rice straw (RS) and oil palm frond (OPF) was investigated. Results showed that RS is a better substrate for production of lovastatin in SSF. Maximum production of lovastatin has been obtained using A. terreus ATCC 74135 and RS as substrate without additional nitrogen source (157.07 mg/kg dry matter (DM)). Although additional nitrogen source has no benefit effect on enhancing the lovastatin production using RS substrate, it improved the lovastatin production using OPF with maximum production of 70.17 and 63.76 mg/kg DM for A. terreus ATCC 20542 and A. terreus ATCC 74135, respectively (soybean meal as nitrogen source). Incubation temperature, moisture content, and particle size had shown significant effect on lovastatin production (P < 0.01) and inoculums size and pH had no significant effect on lovastatin production (P > 0.05). Results also have shown that pH 6, 25°C incubation temperature, 1.4 to 2 mm particle size, 50% initial moisture content, and 8 days fermentation time are the best conditions for lovastatin production in SSF. Maximum production of lovastatin using optimized condition was 175.85 and 260.85 mg/kg DM for A. terreus ATCC 20542 and ATCC 74135, respectively, using RS as substrate.
  16. Faseleh Jahromi M, Liang JB, Ho YW, Mohamad R, Goh YM, Shokryazdan P, et al.
    Biomed Res Int, 2013;2013:604721.
    PMID: 23710454 DOI: 10.1155/2013/604721
    Lovastatin, a natural byproduct of some fungi, is able to inhibit HMG-CoA (3-hydroxy-3 methyl glutaryl CoA) reductase. This is a key enzyme involved in isoprenoid synthesis and essential for cell membrane formation in methanogenic Archaea. In this paper, experiments were designed to test the hypothesis that lovastatin secreted by Aspergillus terreus in fermented rice straw extracts (FRSE) can inhibit growth and CH4 production in Methanobrevibacter smithii (a test methanogen). By HPLC analysis, 75% of the total lovastatin in FRSE was in the active hydroxyacid form, and in vitro studies confirmed that this had a stronger effect in reducing both growth and CH4 production in M. smithii compared to commercial lovastatin. Transmission electron micrographs revealed distorted morphological divisions of lovastatin- and FRSE-treated M. smithii cells, supporting its role in blocking normal cell membrane synthesis. Real-time PCR confirmed that both commercial lovastatin and FRSE increased (P < 0.01) the expression of HMG-CoA reductase gene (hmg). In addition, expressions of other gene transcripts in M. smithii. with a key involvement in methanogenesis were also affected. Experimental confirmation that CH4 production is inhibited by lovastatin in A. terreus-fermented rice straw paves the way for its evaluation as a feed additive for mitigating CH4 production in ruminants.
  17. Wong MV, Ho YW, Tan SG, Abdullah N, Jalaludin S
    FEMS Microbiol Lett, 1995 Dec 01;134(1):9-14.
    PMID: 8593960
    Isolates of anaerobic fungi obtained from the rumen, duodenum and faeces of sheep were identified as Piromyces mae based on their morphological characteristics observed using light microscopy. There was no significant morphological variation among the isolates of P. mae from the rumen, duodenum and faeces. Isozymes of 12 isolates of P. mae (one each from the rumen, duodenum and faeces from 4 different sheep) were analysed by PAGE. A total of 12 isozymes were studied and 5 isozyme loci were successfully typed. They were malic enzyme, malate dehydrogenase, shikimate dehydrogenase, alpha-esterase and beta-esterase. All the isolates of P. mae regardless of whether they were from the rumen, duodenum or faeces or from different animals produced very similar isozyme banding patterns for each of the enzyme systems. The similar isozyme profiles of the isolates indicate that they are of the same species although they exist in different regions of the alimentary tract.
  18. Ho YW, Khoo IY, Tan SG, Abdullah N, Jalaludin S, Kudo H
    Microbiology (Reading), 1994 Jun;140 ( Pt 6):1495-504.
    PMID: 8081508
    Isozymes of 23 cultures of the anaerobic rumen fungi and seven cultures of aerobic chytridiomycete fungi were analysed by PAGE. A total of 14 isozyme loci were successfully typed by PAGE. They were peptidase A & C-1, peptidase A & C-2, peptidase D-1, peptidase D-2, malate dehydrogenase-1, malate dehydrogenase-2, esterase-1, esterase-2, malic enzyme-1, malic enzyme-2, isocitrate dehydrogenase, shikimate dehydrogenase, phosphoglucomutase and 6-phosphogluconate dehydrogenase. Isozyme analysis can be used for studying the genetic relationships among the different anaerobic rumen fungi and the aerobic chytridiomycete fungi and the isozyme characteristics can serve as additional taxonomic criteria in the classification of the anaerobic rumen fungi. A dendrogram based on the isozyme data demonstrated that the anaerobic rumen fungi formed a cluster, indicating a monophyletic group, distinctly separated from the aerobic chytridiomycete fungi. Piromyces communis and P. minutus showed a close relationship but P. spiralis showed a more distant relationship to both P. communis and P. minutus. Piromyces as a whole was more related to Caecomyces than to Neocallimastix. Orpinomyces was also found to be more related to Piromyces and Caecomyces than to Neocallimastix. Orpinomyces intercalaris C 70 from cattle showed large genetic variation from O. joyonii, indicating that it is a different species.
  19. Imai S, Kudo H, Fukuta K, Abudullah N, Ho YW, Onodera R
    J. Eukaryot. Microbiol., 1995 Jan-Feb;42(1):75-7.
    PMID: 7728142
    Isotricha jalaludinii n. sp. found in the rumen of lesser mouse deer, Tragulus javanicus, in Malaysia was described and illustrated. This new species is characterized by the location and direction of the vestibulum, shape of the macronucleus, and absence of a dent at the vestibular opening. The presence of single peculiar isotrichid species in the rumen of mouse deer, which is recognized as one of the most primitive ruminants, suggests that the isotrichid ciliates similar to I. jalaludinii and Isotricha intestinalis were established at a fairly early period during the evolution of ruminants.
  20. Sieo CC, Abdullah N, Tan WS, Ho YW
    Poult Sci, 2005 May;84(5):734-41.
    PMID: 15913185
    Two experiments were conducted to study the effects of beta-glucanase produced by transformed Lactobacillus strains on the intestinal characteristics and feed passage rate of broiler chickens fed barley-based diets. Supplementation of transformed Lactobacillus strains to the diet of chickens significantly (P < 0.05) reduced the intestinal fluid viscosity by 21 to 46% compared with chickens fed an unsupplemented diet or a diet supplemented with parental Lactobacillus strains. The relative weights of pancreas, liver, duodenum, jejunum, ileum, ceca, and colon were reduced (P < 0.05) by 6 to 27%, and the relative length of duodenum, jejunum, ileum, and ceca was reduced (P < 0.05) by 8 to 15%. Histological examination of the intestinal tissues showed that the jejunal villus height of chickens fed a diet supplemented with transformed Lactobacillus strains was significantly (P < 0.05) higher than that of chickens fed other dietary treatments. The transformed Lactobacillus strains were found to reduce (P < 0.05) the time of feed passage rate by 2.2 h. Supplementation of transformed Lactobacillus strains to the diet improved the intestinal characteristics and feed, passage rate of the chickens.
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