MyMedR

Displaying publications 41 - 52 of 52 in total

Abstract:

Sort:

Detection of Escherichia coli O157:H7 in the beef marketed in Malaysia

Radu S, Abdul Mutalib S, Rusul G, Ahmad Z, Morigaki T, Asai N, et al.

Appl Environ Microbiol, 1998 Mar;64(3):1153-6.
PMID: 9501454

Twelve strains of Escherichia coli O157:H7 were isolated from 9 of 25 beef samples purchased from retail stores in Malaysia. These strains produced Shiga toxin 2 with or without Shiga toxin 1 and had the eae gene and a 60-MDa plasmid. The antibiograms and the profiles of the arbitrarily primed PCR of the strains were diverse, suggesting that the strains may have originated from diverse sources.
Occurrence of the vanA and vanC2/C3 genes in Enterococcus species isolated from poultry sources in Malaysia

Radu S, Toosa H, Rahim RA, Reezal A, Ahmad M, Hamid AN, et al.

Diagn Microbiol Infect Dis, 2001 Mar;39(3):145-53.
PMID: 11337180

Enterococcus species isolated from poultry sources were characterized for their resistance to antibiotics, plasmid content, presence of van genes and their diversity by randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). The results showed that all isolates were multi-resistance to the antibiotics tested. Ampicillin (15/70) followed by chloramphenicol (37/70) were the most active antibiotics tested against the Enterococcus spp. isolates, while the overall resistant rates against the other antibiotics were between 64.3% to 100%. All vancomycin-resistant E. faecalis, E. durans, E. hirae and E. faecium isolates tested by the disk diffusion assay were positive in PCR detection for presence of vanA gene. All E. casseliflavus isolates were positive for vanC2/C3 gene. However, none of the Enterococcus spp. isolates were positive for vanB and vanC1 genes. Plasmids ranging in sizes between 1.1 to ca. 35.8 MDa were detected in 38/70 of the Enterococcus isolates. When the genetic relationship among all isolates of the individual species were tested by RAPD-PCR, genetic differences detected suggested a high genetic polymorphisms of isolates in each individual species. Our results indicates that further epidemiological studies are necessary to elucidate the role of food animals as reservoir of VRE and the public health significance of infections caused by Enterococcus spp.
Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia

Thong KL, Goh YL, Radu S, Noorzaleha S, Yasin R, Koh YT, et al.

J Clin Microbiol, 2002 Jul;40(7):2498-503.
PMID: 12089269

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.
Molecular characterization of Vibrio cholerae O1 outbreak strains in Miri, Sarawak (Malaysia)

Radu S, Vincent M, Apun K, Abdul-Rahim R, Benjamin PG, Yuherman, et al.

Acta Trop, 2002 Aug;83(2):169-76.
PMID: 12088858

Bacterial resistance to various antimicrobial agents is common in area with high usage of antibiotics. In this study, the data on antimicrobial susceptibility patterns of Vibrio cholerae O1 from patients during an outbreak period was found to be high but variable rates of multidrug resistance. Thirty-two of 33 V. cholerae isolates harboured the tcp, ctx, zot and ace genes, suggesting their possible roles in the outbreak cases. We analyzed the molecular diversity of a total of 33 strains of V. cholerae O1 isolated from 33 patients between November 1997 and April 1998 using random amplified polymorphic DNA (RAPD) analysis. The 30 typable isolates could be separated into four major clusters containing 5, 17, 2 and 6 isolates, respectively. However, no particular RAPD pattern was predictive of a particular pattern of antibiotic susceptibility. The findings of this study showed that multiple clones seemed to be responsible for cases in the outbreaks in the study area.
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.
Lactobacillus durianis sp. nov., isolated from an acid-fermented condiment (tempoyak) in Malaysia

Leisner JJ, Vancanneyt M, Lefebvre K, Vandemeulebroecke K, Hoste B, Vilalta NE, et al.

Int J Syst Evol Microbiol, 2002 May;52(Pt 3):927-931.
PMID: 12054259 DOI: 10.1099/00207713-52-3-927

Lactic acid bacteria (LAB) are the predominant micro-organisms in tempoyak, a Malaysian acid-fermented condiment. In a study on the diversity of LAB in this product, three isolates could not be identified using SDS-PAGE of whole-cell proteins or API 50 CH. The taxonomic position of the three isolates was clarified in the present study. 16S rDNA sequencing classified a representative strain in the genus Lactobacillus, clearly separated from all known species, and most closely related to the Lactobacillus reuteri phylogenetic group. DNA-DNA hybridization experiments and an extensive phenotypic description confirm that the strains represent a single and separate novel species among the obligately heterofermentative lactobacilli. The three isolates are distinguished at the intra-species level by plasmid profiling, pulsed-field gel electrophoresis of macro-restriction fragments and biochemical features. The name Lactobacillus durianis sp. nov. is proposed for the novel taxon and the type strain is LMG 19193T (= CCUG 45405T).
Growth properties and cholesterol removal ability of electroporated Lactobacillus acidophilus BT 1088

Lye HS, Khoo BY, Karim AA, Rusul G, Liong MT

J Microbiol Biotechnol, 2012 Jul;22(7):981-9.
PMID: 22580318

This study aimed to evaluate the effects of electroporation on the cell growth, cholesterol removal, and adherence abilities of L. acidophilus BT 1088 and their subsequent passages. The growth of electroporated parent cells increased (P<0.05) by 4.49-21.25% compared with that of the control. This may be attributed to the alteration of cellular membrane. However, growth of first, second, and third passages of treated cells was comparable with that of the control, which may be attributed to the resealing of transient pores on the cellular membrane. Electroporation also increased (P<0.05) assimilation of cholesterol by treated parent cells (>185.40%) and first passage (>21.72%) compared with that of the control. Meanwhile, incorporation of cholesterol into the cellular membrane was also increased (P<0.05) in the treated parent cells (>108.33%) and first passage (>26.67%), accompanied by increased ratio of cholesterol:phospholipids (C:P) in these passages. Such increased ratio was also supported by increased enrichment of cholesterol in the hydrophilic heads, hydrophobic tails, and the interface regions of the membrane phospholipids of both parent and first passage cells compared with that of the control. However, such traits were not inherited by the subsequent second and third passages. Parent cells also showed decreased intestinal adherence ability (P<0.05; decreased by 1.45%) compared with that of the control, without inheritance by subsequent passages of treated cells. Our data suggest that electoporation could be a potential physical treatment to enhance the cholesterol removal ability of lactobacilli that was inherited by the first passage of treated cells without affecting their intestinal adherence ability.
Composition, physicochemical properties and thermal inactivation kinetics of polyphenol oxidase and peroxidase from coconut (Cocos nucifera) water obtained from immature, mature and overly-mature coconut

Tan TC, Cheng LH, Bhat R, Rusul G, Easa AM

Food Chem, 2014 Jan 1;142:121-8.
PMID: 24001821 DOI: 10.1016/j.foodchem.2013.07.040

Composition, physicochemical properties and enzyme inactivation kinetics of coconut water were compared between immature (IMC), mature (MC) and overly-mature coconuts (OMC). Among the samples studied, pH, turbidity and mineral contents for OMC water was the highest, whereas water volume, titratable acidity, total soluble solids and total phenolics content for OMC water were the lowest. Maturity was found to affect sugar contents. Sucrose content was found to increase with maturity, and the reverse trend was observed for fructose and glucose. Enzyme activity assessment showed that polyphenol oxidase (PPO) in all samples was more heat resistant than peroxidase (POD). Compared to IMC and MC, PPO and POD from OMC water showed the lowest thermal resistance, with D83.3°C=243.9s (z=27.9°C), and D83.3°C=129.9s (z=19.5°C), respectively.
Physio-chemical, microbiological properties of tempoyak and molecular characterisation of lactic acid bacteria isolated from tempoyak

Chuah LO, Shamila-Syuhada AK, Liong MT, Rosma A, Thong KL, Rusul G

Food Microbiol, 2016 Sep;58:95-104.
PMID: 27217364 DOI: 10.1016/j.fm.2016.04.002

This study aims to determine physio-chemical properties of tempoyak, characterise the various indigenous species of lactic acid bacteria (LAB) present at different stages of fermentation and also to determine the survival of selected foodborne pathogens in tempoyak. The predominant microorganisms present in tempoyak were LAB (8.88-10.42 log CFU/g). Fructobacillus durionis and Lactobacillus plantarum were the dominant members of LAB. Other LAB species detected for the first time in tempoyak were a fructophilic strain of Lactobacillus fructivorans, Leuconostoc dextranicum, Lactobacillus collinoides and Lactobacillus paracasei. Heterofermentative Leuconostoc mesenteroides and F. durionis were predominant in the initial stage of fermentation, and as fermentation proceeded, F. durionis remained predominant, but towards the end of fermentation, homofermentative Lb. plantarum became the predominant species. Lactic, acetic and propionic acids were present in concentrations ranging from 0.30 to 9.65, 0.51 to 7.14 and 3.90 to 7.31 mg/g, respectively. Genotyping showed a high degree of diversity among F. durionis and Lb. plantarum isolates, suggesting different sources of LAB. All tested Lb. plantarum and F. durionis (except for one isolate) isolates were multidrug resistant. Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were not detected. However, survival study showed that these pathogens could survive up to 8-12 days. The results aiming at improving the quality and safety of tempoyak.
Fulltext Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia

Budiati T, Rusul G, Wan-Abdullah WN, Chuah LO, Ahmad R, Thong KL

J Food Prot, 2016 Apr;79(4):659-65.
PMID: 27052872 DOI: 10.4315/0362-028X.JFP-15-372

A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.
Fulltext Genome Sequence of "Anthococcus," a Novel Genus of the Family Streptococcaceae Isolated from Flowers

Chuah LO, Yap KP, Thong KL, Liong MT, Ahmad R, Shamila-Syuhada AK, et al.

Genome Announc, 2016 Dec 15;4(6).
PMID: 27979953 DOI: 10.1128/genomeA.01410-16

Here, we report the draft whole-genome sequence of "Anthococcus," a novel genus of the family Streptococcaceae isolated from fresh flowers of a durian (Durio zibethinus) tree. The draft genome of Anthococcus sp. strain DF1 contains 2,157,756 bp, with a G+C content of 33.0%.
Fulltext Prevalence of Salmonella in poultry processing environments in wet markets in Penang and Perlis, Malaysia

Nidaullah H, Abirami N, Shamila-Syuhada AK, Chuah LO, Nurul H, Tan TP, et al.

Vet World, 2017 Mar;10(3):286-292.
PMID: 28435190 DOI: 10.14202/vetworld.2017.286-292

AIM: The aim of this study was to determine the prevalence of various Salmonella serotypes in chickens, carcass contact surfaces as well as environmental samples collected from wet markets and small scale processing plant.
MATERIALS AND METHODS: A total of 182 poultry and environmental samples were collected at random on separate occasions from wet markets and small scale processing plant, during the period of October 2014 to July 2015 in Penang and Perlis, Malaysia. The samples were analyzed for the presence of Salmonella using ISO 6579:2002 conventional culture-based method. Presumptive Salmonella colonies were subjected to various biochemical tests (such as triple sugar iron and lysine iron test), serologically confirmed using polyvalent O and H antisera and further serotyped at Public Health Laboratory, Ministry of Health, Perak, Malaysia.
RESULTS: Salmonella serotypes were isolated from 161 out of 182 samples (88.46%) with 100% prevalence in the whole chicken carcass and chicken cuts - as well as transport crate, cage, drum, knife, chopping board, display table, floor, bench wash water, wash water, and drain water. Salmonella was isolated from 91.67%, 83.33%, and 66.67% of defeathering machines, drain swabs, and apron, respectively. 17 serotypes were isolated in this study with Salmonella Albany (57/161), Salmonella Corvallis (42/161), and Salmonella Brancaster (37/161) being the predominant serovars.
CONCLUSION: The most carcass contact and environmental samples collected along the wet market chicken processing line were consistently contaminated with Salmonella. This indicates that Salmonella has established itself in poultry processing environments by colonizing the surfaces of the equipment and survives in these environments by establishing biofilms. Our results highlight the need of implementing strict hygiene and sanitation standards to reduce the incidence of Salmonella. The prevalence of Salmonella in poultry can be reduced effectively by identifying and eliminating the sources and contamination sites during slaughter and processing of poultry.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links