Displaying publications 1 - 20 of 42 in total

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  1. Isolation and identification of a new intracellular antimicrobial peptide produced by Paenibacillus alvei AN5
    Alkotaini B, Anuar N, Kadhum AA, Sani AA
    World J Microbiol Biotechnol, 2014 Apr;30(4):1377-85.
    PMID: 24272828 DOI: 10.1007/s11274-013-1558-z
    A wild-type, Gram-positive, rod-shaped, endospore-forming and motile bacteria has been isolated from palm oil mill sludge in Malaysia. Molecular identification using 16S rRNA gene sequence analysis indicated that the bacteria belonged to genus Paenibacillus. With 97 % similarity to P. alvei (AUG6), the isolate was designated as P. alvei AN5. An antimicrobial compound was extracted from P. alvei AN5-pelleted cells using 95 % methanol and was then lyophilized. Precipitates were re-suspended in phosphate buffered saline (PBS), producing an antimicrobial crude extract (ACE). The ACE showed antimicrobial activity against Salmonella enteritidis ATCC 13076, Escherichia coli ATCC 29522, Bacillus cereus ATCC 14579 and Lactobacillus plantarum ATCC 8014. By using SP-Sepharose cation exchange chromatography, Sephadex G-25 gel filtration and Tricine SDS-PAGE, the ACE was purified, which produced a ~2-kDa active band. SDS-PAGE and infrared (IR) spectroscopy indicated the proteinaceous nature of the antimicrobial compound in the ACE, and liquid chromatography electrospray ionization mass spectroscopy and de novo sequencing using an automatic, Q-TOF premier system detected a peptide with the amino acid sequence F-C-K-S-L-P-L-P-L-S-V-K (1,330.7789 Da). This novel peptide was designated as AN5-2. The antimicrobial peptide exhibited stability from pH 3 to 12 and maintained its activity after being heated to 90 °C. It also remained active after incubation with denaturants (urea, SDS and EDTA).
    Matched MeSH terms: Environmental Microbiology
  2. Fulltext Extracellular enzyme profiling of Stenotrophomonas maltophilia clinical isolates
    Thomas R, Hamat RA, Neela V
    Virulence, 2014 Feb 15;5(2):326-30.
    PMID: 24448556 DOI: 10.4161/viru.27724
    Matched MeSH terms: Environmental Microbiology
  3. Genetic characterization of Arcobacter isolates from various sources
    Shah AH, Saleha AA, Zunita Z, Cheah YK, Murugaiyah M, Korejo NA
    Vet Microbiol, 2012 Dec 7;160(3-4):355-61.
    PMID: 22739058 DOI: 10.1016/j.vetmic.2012.05.037
    Arcobacter is getting more attention due to its detection from wide host-range and foods of animal origin. The objective of this study was to determine the prevalence of Arcobacter spp. in various sources at farm level and beef retailed in markets in Malaysia and to assess the genetic relatedness among them. A total of 273 samples from dairy cattle including cattle (n=120), floor (n=30), water (n=18) and milk (n=105) as well as 148 beef samples collected from retail markets were studied. The overall prevalence of Arcobacter in various sources was 15% (63/421). However, source-wise detection rate of Arcobacter spp. was recorded as 26.66% (8/30) in floor, 26.3% (39/148) in beef, 11.11% (2/18) in water, 7.6% (8/105) in milk and 6.66% (8/120) in cattle. Arcobacter butzleri was the frequently isolated species however, a total of 75%, 66.7%, 53.8%, 50% and 12.5%% samples from floor, milk, beef, water and cattle, respectively, were carrying more than one species simultaneously. One (12.5%) cattle and beef sample (2.5%) found to be carrying one Arcobacter spp., A. skirrowii, only. Typing of Arcobacter isolates was done though pulsed field gel electrophoresis (PFGE) after digested with Eag1 restriction endonuclease (RE). Digestion of genomic DNA of Arcobacter from various sources yielded 12 major clusters (≥ 50% similarity) which included 29 different band patterns. A number of closely related A. butzleri isolates were found from beef samples which indicate cross contamination of common type of Arcobacter. Fecal shedding of Arcobacter by healthy animals can contaminate water and milk which may act as source of infection in humans.
    Matched MeSH terms: Environmental Microbiology*
  4. Molecular epidemiology of Clostridium difficile isolated from piglets
    Putsathit P, Neela VK, Joseph NMS, Ooi PT, Ngamwongsatit B, Knight DR, et al.
    Vet Microbiol, 2019 Oct;237:108408.
    PMID: 31585650 DOI: 10.1016/j.vetmic.2019.108408
    Information on the epidemiology of C. difficile infection (CDI) in South-East Asian countries is limited, as is data on possible animal reservoirs of C. difficile in the region. We investigated the prevalence and molecular epidemiology of C. difficile in piglets and the piggery environment in Thailand and Malaysia. Piglet rectal swabs (n = 224) and piggery environmental specimens (n = 23) were collected between 2015 and 2016 from 11 farms located in Thailand and Malaysia. All specimens were tested for the presence of C. difficile with toxigenic culture. PCR assays were performed on isolates to determine the ribotype (RT), and the presence of toxin genes. Whole genome sequencing was used on a subset of isolates to determine the evolutionary relatedness of RT038 (the most prevalent RT identified) common to pigs and humans from Thailand and Indonesia. C. difficile was recovered from 35% (58/165) and 92% (54/59) of the piglets, and 89% (8/9) and 93% (13/14) of the environmental specimens from Thailand and Malaysia, respectively. All strains from Thailand, and 30 strains from Malaysia (23 piglet and 7 environmental isolates) were non-toxigenic. To our knowledge, this is the first and only report with a complete lack of toxigenic C. difficile among piglets, a feature which could have a protective effect on the host. The most common strain belonged to RT038 (ST48), accounting for 88% (51/58) of piglet and 78% (7/9) of environmental isolates from Thailand, and all 30 isolates tested from Malaysia. Piglet RT038 isolates from Thailand and Malaysia differed by only 18 core-genome single nucleotide variants (cgSNVs) and both were, on average, 30 cgSNVs different from the human strains from Thailand and Indonesia, indicating a common ancestor in the last two decades.
    Matched MeSH terms: Environmental Microbiology
  5. Fulltext Enzymatic profiling of clinical and environmental isolates of Burkholderia pseudomallei
    Liew SM, Tay ST, Wongratanacheewin S, Puthucheary SD
    Trop Biomed, 2012 Mar;29(1):160-8.
    PMID: 22543616 MyJurnal
    Melioidosis has been recognized as an important cause of sepsis in the tropics. The disease caused by an environmental saprophyte Burkholderia pseudomallei, affects mostly adults with underlying immunocompromised conditions. In this study, the enzymatic profiles of 91 clinical and 9 environmental isolates of B. pseudomallei were evaluated using the APIZYM system, in addition to assessment of protease, phospholipase C and sialidase activities using agar plate methods and other assays. The activity of 10 enzymes - alkaline phosphatase, esterase, esterase lipase, lipase, leucine arylamidase, valine arylamidase, cystine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and N-acetyl-β-glucosaminidase were detected in >75% of the clinical isolates. The majority of B. pseudomallei isolates in this study exhibited protease and phospholipase activities. No sialidase activity was detected. Five Burkholderia thailandensis isolates had similar APIZYM profiles as B. pseudomallei clinical isolates except for the lower detection rate for N-acetyl-β-glucosaminidase. The subtle differences in the number of enzymes secreted and the levels of enzymatic activities of phenotypically identical clinical and environmental strains of B. pseudomallei give weight to the fact that the causative agent of melioidodis originates from the environment.
    Matched MeSH terms: Environmental Microbiology*
  6. Fulltext Anti-Candida activity and biofilm inhibitory effects of secreted products of tropical environmental yeasts
    Tan HW, Tay ST
    Trop Biomed, 2011 Apr;28(1):175-80.
    PMID: 21602784
    This study describes the killer phenotypes of tropical environmental yeasts and the inhibition effects of the culture filtrates on the biofilm of Candida albicans. A total of 26 (10.5%) of 258 yeast isolates obtained from an environmental sampling study demonstrated killer activity to Candida species. The killer yeasts were identified as species belonging to the genus Aureobasidium, Pseudozyma, Ustilago and Candida based on sequence analysis of the ITS1-5.8S-ITS2 region of the yeasts. Pseudozyma showed the broadest killing effects against sensitive strains of Candida. New species of Ustilago and Pseudozyma demonstrating killer phenotypes were identified in this study. Interestingly, more than 50% reduction in the metabolic activity of Candida albicans biofilm was noted after exposure to the culture filtrates of the nine killer yeasts. Purification and characterization of toxin and metabolites are essential for understanding the yeast killing effects.
    Matched MeSH terms: Environmental Microbiology*
  7. Isolation of indigenous larvicidal microbial control agents of mosquitos: the Malaysian experience
    Lee HL, Seleena P
    Southeast Asian J. Trop. Med. Public Health, 1990 Jun;21(2):281-7.
    PMID: 2237596
    A nationwide screening program searching for microbial control agents of mosquitos was initiated in Malaysia in 1986. A total of 725 samples were collected and 2,394 bacterial colonies were isolated and screened for larvicidal activity. From such screening, 20 Bacillus thuringiensis, 6 B. sphaericus, 1 Clostridium bifermentans and 2 Pseudomonas pseudomallei larvicidal isolates were obtained. Of these, a new B. thuringiensis named as subspecies malaysianensis was found, while the C. bifermentans was also a new anaerobe individualized as serovar malaysia. It was concluded that this screening program was highly successful.
    Matched MeSH terms: Environmental Microbiology
  8. Fulltext Clearing the air about "the haze"
    Jeyaindran S
    Med J Malaysia, 2006 Mar;61(1):117-21.
    PMID: 16708750
    From the beginning of time, man has lived in a continuous state of interdependence with his environment. If the forces of nature are harnessed well, they are a source of great benefit to mankind, but when this balance is tipped, nature's backlash on man can be quite devastating. In recent times, we have seen many vivid examples of the magnitude of the destructive forces of nature, ranging from massive floods caused by typhoons such as Katrina and Rita, the hundreds of thousands of lives lost by the powerful tsunami and the destruction of the environment by the raging forest fires in Spain and California. Yet man has not learnt his lesson. Often greed, at times gross ignorance and more often than not, just indifference to the effects of his actions on the environment result in man upsetting his balance with the environment. In Malaysia, since 1990, the haze has become a predictable annual occurrence, varying only in its severity and duration. The cause being beyond our control, we are unable to prevent it from happening. However, it is within our means to be ready to take the necessary steps to minimize the effects of the haze on the health of Malaysians. In order to be able to give appropriate advice and to allay the anxiety of the general public, it is necessary to have a clear understanding about the various effects of haze on humans.
    Matched MeSH terms: Environmental Microbiology
  9. Fulltext An Analysis Review of Detection Coronavirus Disease 2019 (COVID-19) Based on Biosensor Application
    Taha BA, Al Mashhadany Y, Hafiz Mokhtar MH, Dzulkefly Bin Zan MS, Arsad N
    Sensors (Basel), 2020 Nov 26;20(23).
    PMID: 33256085 DOI: 10.3390/s20236764
    Timely detection and diagnosis are essentially needed to guide outbreak measures and infection control. It is vital to improve healthcare quality in public places, markets, schools and airports and provide useful insights into the technological environment and help researchers acknowledge the choices and gaps available in this field. In this narrative review, the detection of coronavirus disease 2019 (COVID-19) technologies is summarized and discussed with a comparison between them from several aspects to arrive at an accurate decision on the feasibility of applying the best of these techniques in the biosensors that operate using laser detection technology. The collection of data in this analysis was done by using six reliable academic databases, namely, Science Direct, IEEE Xplore, Scopus, Web of Science, Google Scholar and PubMed. This review includes an analysis review of three highlights: evaluating the hazard of pandemic COVID-19 transmission styles and comparing them with Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) to identify the main causes of the virus spreading, a critical analysis to diagnose coronavirus disease 2019 (COVID-19) based on artificial intelligence using CT scans and CXR images and types of biosensors. Finally, we select the best methods that can potentially stop the propagation of the coronavirus pandemic.
    Matched MeSH terms: Environmental Microbiology
  10. Fulltext Genome-Wide Transcription Study of Cryptococcus neoformans H99 Clinical Strain versus Environmental Strains
    Movahed E, Munusamy K, Tan GM, Looi CY, Tay ST, Wong WF
    PLoS One, 2015;10(9):e0137457.
    PMID: 26360021 DOI: 10.1371/journal.pone.0137457
    The infection of Cryptococcus neoformans is acquired through the inhalation of desiccated yeast cells and basidiospores originated from the environment, particularly from bird's droppings and decaying wood. Three environmental strains of C. neoformans originated from bird droppings (H4, S48B and S68B) and C. neoformans reference clinical strain (H99) were used for intranasal infection in C57BL/6 mice. We showed that the H99 strain demonstrated higher virulence compared to H4, S48B and S68B strains. To examine if gene expression contributed to the different degree of virulence among these strains, a genome-wide microarray study was performed to inspect the transcriptomic profiles of all four strains. Our results revealed that out of 7,419 genes (22,257 probes) examined, 65 genes were significantly up-or down-regulated in H99 versus H4, S48B and S68B strains. The up-regulated genes in H99 strain include Hydroxymethylglutaryl-CoA synthase (MVA1), Mitochondrial matrix factor 1 (MMF1), Bud-site-selection protein 8 (BUD8), High affinity glucose transporter 3 (SNF3) and Rho GTPase-activating protein 2 (RGA2). Pathway annotation using DAVID bioinformatics resource showed that metal ion binding and sugar transmembrane transporter activity pathways were highly expressed in the H99 strain. We suggest that the genes and pathways identified may possibly play crucial roles in the fungal pathogenesis.
    Matched MeSH terms: Environmental Microbiology*
  11. Fulltext Association of some Campylobacter jejuni with Pseudomonas aeruginosa biofilms increases attachment under conditions mimicking those in the environment
    Teh AHT, Lee SM, Dykes GA
    PLoS One, 2019;14(4):e0215275.
    PMID: 30970009 DOI: 10.1371/journal.pone.0215275
    Campylobacter jejuni is a microaerophilic bacterial species which is a major food-borne pathogen worldwide. Attachment and biofilm formation have been suggested to contribute to the survival of this fastidious bacteria in the environment. In this study the attachment of three C. jejuni strains (C. jejuni strains 2868 and 2871 isolated from poultry and ATCC 33291) to different abiotic surfaces (stainless steel, glass and polystyrene) alone or with Pseudomonas aeruginosa biofilms on them, in air at 25°C and under static or flow conditions, were investigated using a modified Robbins Device. Bacteria were enumerated and scanning electron microscopy was carried out. The results indicated that both C. jejuni strains isolated from poultry attached better to Pseudomonas aeruginosa biofilms on abiotic surfaces than to the surfaces alone under the different conditions tested. This suggests that biofilms of other bacterial species may passively protect C. jejuni against shear forces and potentially oxygen stress which then contribute to their persistence in environments which are detrimental to them. By contrast the C. jejuni ATCC 33291 strain did not attach differentially to P. aeruginosa biofilms, suggesting that different C. jejuni strains may have alternative strategies for persistence in the environment. This study supports the hypothesis that C. jejuni do not form biofilms per se under conditions they encounter in the environment but simply attach to surfaces or biofilms of other species.
    Matched MeSH terms: Environmental Microbiology
  12. Enzymatic characterisation of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii and other environmental Cryptococcus spp
    Chan MY, Tay ST
    Mycoses, 2010 Jan;53(1):26-31.
    PMID: 19389064 DOI: 10.1111/j.1439-0507.2008.01654.x
    This study compared the enzymatic activity of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii, environmental isolates of C. neoformans and non-neoformans Cryptococcus. Most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. Laccase activity was detected from all the C. neoformans and C. gattii isolates, but not from the non-neoformans Cryptococcus isolates. There was no significant difference in the proteinase, phospholipase and laccase activities of C. neoformans and C. gattii. However, significant difference in the enzymatic activities of beta-glucuronidase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase between C. neoformans and C. gattii isolates was observed in this study. Environmental isolates of C. neoformans exhibited similar enzymatic profiles as the clinical isolates of C. neoformans, except for lower proteinase and laccase activities.
    Matched MeSH terms: Environmental Microbiology
  13. Natural occurrence and growth reaction on canavanine-glycine-bromothymol blue agar of non-neoformans Cryptococcus spp. in Malaysia
    Tay ST, Na SL, Tajuddin TH
    Mycoses, 2008 Nov;51(6):515-9.
    PMID: 18498307 DOI: 10.1111/j.1439-0507.2008.01516.x
    Cryptococcus albidus and C. laurentii were the predominant non-neoformans cryptococci isolated during an environmental sampling study for C. gattii at Klang Valley, Malaysia. Cryptococcus gattii was not isolated from any of the environmental samples. Cryptococcus albidus and C. laurentii were isolated mainly from vegetative samples of Eucalyptus trees and bird droppings. Upon testing on canavanine-glycine-bromothymol blue (CGB) agar, all the C. albidus isolates remained unchanged. Interestingly, a total of 29 (76.3%) C. laurentii isolates formed blue colours on the CGB agar. Sequence analysis of ITS1-5.8rDNA-ITS2 gene sequences (468 bp) of four CGB-blue C. laurentii isolates demonstrated the closest match (99%) with that of C. laurentii CBS 7140. This study demonstrated the diverse environmental niche of C. albidus and C. laurentii in Malaysia.
    Matched MeSH terms: Environmental Microbiology*
  14. Proteomic profiling of clinical and environmental strains of Pseudomonas aeruginosa
    Liew SM, Puthucheary SD, Rajasekaram G, Chai HC, Chua KH
    Mol Biol Rep, 2021 Mar;48(3):2325-2333.
    PMID: 33728559 DOI: 10.1007/s11033-021-06262-8
    Pseudomonas aeruginosa is a ubiquitous bacterium, which is able to change its physiological characteristics in response to different habitats. Environmental strains are presumably less pathogenic than clinical strains and whether or not the clinical strains originate from the environment or through inter-host transmission remains poorly understood. To minimize the risk of infection, a better understanding of proteomic profiling of P. aeruginosa is necessary for elucidating the correlation between environmental and clinical strains. Based on antimicrobial susceptibility and patterns of virulence, we selected 12 clinical and environmental strains: (i) environmental, (ii) multidrug resistant (MDR) clinical and (iii) susceptible clinical strains. Whole-cell protein was extracted from each strain and subjected to two-dimensional differential gel electrophoresis (2-D DIGE) and liquid chromatography tandem mass spectrometry quadrupole time-of-flight (LC-MS QTOF). All 12 strains were clustered into 3 distinct groups based on their variance in protein expression. A total of 526 matched spots were detected and four differentially expressed protein spots (p < 0.05) were identified and all differential spots were downregulated in MDR strain J3. Upregulation of chitin binding and BON domain proteins was present in the environmental and some MDR strains, whereas the clinical strains exhibited distinct proteomic profiles with increased expression of serine protein kinase and arginine/ornithine transport ATP-binding proteins. Significant difference in expression was observed between susceptible clinical and MDR strains, as well as susceptible clinical and environmental strains. Transition from an environmental saprophyte to a clinical strain could alter its physiological characteristics to further increase its adaptation.
    Matched MeSH terms: Environmental Microbiology*
  15. Isolation, identification and diesel-oil biodegradation capacities of indigenous hydrocarbon-degrading strains of Cellulosimicrobium cellulans and Acinetobacter baumannii from tarball at Terengganu beach, Malaysia
    Nkem BM, Halimoon N, Yusoff FM, Johari WLW, Zakaria MP, Medipally SR, et al.
    Mar Pollut Bull, 2016 Jun 15;107(1):261-268.
    PMID: 27085593 DOI: 10.1016/j.marpolbul.2016.03.060
    In this study, we isolated two indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source. Results analysed using GC-MS, showed diesel-oil alkanes were degraded an average 64.4% by C. cellulans and 58.1% by A. baumannii with medium optical density reaching 0.967 (C. cellulans) and 1.515 (A. baumannii) in minimal salt media at 32°C for 10days. Individual diesel-oil alkanes were degraded between 10%-95.4% by C. cellulans and 0.2%-95.9% by A. baumannii. Both strains utilized diesel-oil for growth. The study suggests both strains are part of indigenous hydrocarbon-degrading bacteria in tarball with potential for bioremediation of oil-polluted marine environment.
    Matched MeSH terms: Environmental Microbiology
  16. Fulltext Toxic effect of high concentration of sonochemically synthesized polyvinylpyrrolidone-coated silver nanoparticles on Citrobacter sp. A1 and Enterococcus sp. C1
    Lau CP, Abdul-Wahab MF, Jaafar J, Chan GF, Abdul Rashid NA
    J Microbiol Immunol Infect, 2017 Aug;50(4):427-434.
    PMID: 26427880 DOI: 10.1016/j.jmii.2015.08.004
    BACKGROUND/PURPOSE: Currently, silver nanoparticles (AgNPs) have gained importance in various industrial applications. However, their impact upon release into the environment on microorganisms remains unclear. The aim of this study was to analyze the effect of polyvinylpyrrolidone-capped AgNPs synthesized in this laboratory on two bacterial strains isolated from the environment, Gram-negative Citrobacter sp. A1 and Gram-positive Enterococcus sp. C1.

    METHODS: Polyvinylpyrrolidone-capped AgNPs were synthesized by ultrasound-assisted chemical reduction. Characterization of the AgNPs involved UV-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. Citrobacter sp. A1 and Enterococcus sp. C1 were exposed to varying concentrations of AgNPs, and cell viability was determined. Scanning electron microscopy was performed to evaluate the morphological alteration of both species upon exposure to AgNPs at 1000 mg/L.

    RESULTS: The synthesized AgNPs were spherical in shape, with an average particle size of 15 nm. The AgNPs had different but prominent effects on either Citrobacter sp. A1 or Enterococcus sp. C1. At an AgNP concentration of 1000 mg/L, Citrobacter sp. A1 retained viability for 6 hours, while Enterococcus sp. C1 retained viability only for 3 hours. Citrobacter sp. A1 appeared to be more resistant to AgNPs than Enterococcus sp. C1. The cell wall of both strains was found to be morphologically altered at that concentration.

    CONCLUSION: Minute and spherical AgNPs significantly affected the viability of the two bacterial strains selected from the environment. Enterococcus sp. C1 was more vulnerable to AgNPs, probably due to its cell wall architecture and the absence of silver resistance-related genes.

    Matched MeSH terms: Environmental Microbiology
  17. Fulltext Genetic diversity of toxigenic Vibrio cholerae O1 from Sabah, Malaysia 2015
    Zaw MT, Emran NA, Ibrahim MY, Suleiman M, Awang Mohd TA, Yusuff AS, et al.
    J Microbiol Immunol Infect, 2019 Aug;52(4):563-570.
    PMID: 29428381 DOI: 10.1016/j.jmii.2018.01.003
    BACKGROUND: Cholera is an important health problem in Sabah, a Malaysian state in northern Borneo; however, Vibrio cholerae in Sabah have never been characterized. Since 2002, serogroup O1 strains having the traits of both classical and El Tor biotype, designated as atypical El Tor biotype, have been increasingly reported as the cause of cholera worldwide. These variants are believed to produce clinically more severe disease like classical strains.

    PURPOSE: The purpose of this study is to investigate the genetic diversity of V.cholerae in Sabah and whether V.cholerae in Sabah belong to atypical El Tor biotype.

    METHODS: ERIC-PCR, a DNA fingerprinting method for bacterial pathogens based on the enterobacterial repetitive intergenic consensus sequence, was used to study the genetic diversity of 65 clinical V.cholerae O1 isolates from 3 districts (Kudat, Beluran, Sandakan) in Sabah and one environmental isolate from coastal sea water in Kudat district. In addition, we studied the biotype-specific genetic traits in these isolates to establish their biotype.

    RESULTS: Different fingerprint patterns were seen in isolates from these three districts but one of the patterns was seen in more than one district. Clinical isolates and environmental isolate have different patterns. In addition, Sabah isolates harbor genetic traits specific to both classical biotype (ctxB-1, rstRCla) and El Tor biotype (rstRET, rstC, tcpAET, rtxC, VC2346).

    CONCLUSION: This study revealed that V.cholerae in Sabah were genetically diverse and were atypical El Tor strains. Fingerprint patterns of these isolates will be useful in tracing the origin of this pathogen in the future.

    Matched MeSH terms: Environmental Microbiology
  18. Isolation and characterization of purple non-sulfur bacteria, Afifella marina, producing large amount of carotenoids from mangrove microhabitats
    Kar Soon T, Al-Azad S, Ransangan J
    J Microbiol Biotechnol, 2014 Aug;24(8):1034-43.
    PMID: 24759424
    This study determined the effect of light intensity and photoperiod on the dry cell weight and total amount of carotenoids in four isolates of purple non-sulfur bacteria obtained from shaded and exposed microhabitats of a mangrove ecosystem in Kota Kinabalu, Sabah, Malaysia. The initial isolation of the bacteria was carried out using synthetic 112 medium under anaerobic conditions (2.5 klx) at 30 ± 2°C. On the basis of colony appearance, cell morphology, gram staining, motility test, and 16S rRNA gene sequencing analyses, all four bacteria were identified as Afifella marina. One of the bacterial isolates, designated as Af. marina strain ME, which was extracted from an exposed mud habitat within the mangrove ecosystem, showed the highest yield in dry cell weight (4.32± 0.03 g/l) as well as total carotenoids (0.783 ± 0.002 mg/g dry cell weight). These values were significantly higher than those for dry cell weight (3.77 ± 0.02g/l ) and total carotenoid content (0.706 ± 0.008 mg/g) produced by the isolates from shaded habitats. Further analysis of the effect of 10 levels of light intensity on the growth characteristics of Af. marina strain ME showed that the optimum production of dry cell weight and total carotenoids was achieved at different light intensities and incubation periods. The bacterium produced the highest dry cell weight of 4.98 g/l at 3 klx in 72 h incubation, but the carotenoid production of 0.783 mg/g was achieved at 2.5 klx in 48 h incubation. Subsequent analysis of the effect of photoperiod on the production of dry cell weight and total carotenoids at optimum light intensities (3 and 2.5 klx, respectively) revealed that 18 and 24 h were the optimum photoperiods for the production of dry cell weight and total carotenoids, respectively. The unique growth characteristics of the Af. marina strain ME can be exploited for biotechnology applications.
    Matched MeSH terms: Environmental Microbiology*
  19. Fulltext Genetic diversity of Enterococcus faecalis isolated from environmental, animal and clinical sources in Malaysia
    Daniel DS, Lee SM, Gan HM, Dykes GA, Rahman S
    J Infect Public Health, 2017 02 21;10(5):617-623.
    PMID: 28254461 DOI: 10.1016/j.jiph.2017.02.006
    Enterococcus faecalis ranks as one of the leading causes of nosocomial infections. A strong epidemiological link has been reported between E. faecalis inhabiting animals and environmental sources. This study investigates the genetic diversity, antibiotic resistance and virulence determinants in E. faecalis from three sources in Malaysia. A total of 250 E. faecalis isolates were obtained consisting of 120 isolates from farm animals, 100 isolates from water sources and 30 isolates from hospitalized patients. Pulse-field gel electrophoresis-typing yielded 63 pulsotypes, with high diversity observed in all sources (D=≥0.901). No pulsotype was common to all the three sources. Each patient room had its own unique PFGE pattern which persisted after six months. Minimum inhibitory concentrations of Vancomycin, Gentamicin, Penicillin, Tetracycline, Nitrofurantoin, Levofloxacin, Ciprofloxacin and Fosfomycin were evaluated. Resistance to Tetracycline was most prevalent in isolates from farm animals (62%) and water sources (49%). Water isolates (86%) had a higher prevalence of the asa1 gene, which encodes for aggregation substance, whereas clinical (78%) and farm animal isolates (87%) had a higher prevalence of the esp gene, encoding a surface exposed protein. This study generates knowledge on the genetic diversity of E. faecalis with antibiotic resistance and virulence characteristics from various sources in Malaysia.
    Matched MeSH terms: Environmental Microbiology
  20. Fulltext High Occurrence of Staphylococcus aureus Isolated from Fitness Equipment from Selected Gymnasiums
    Maurice Bilung L, Tahar AS, Kira R, Mohd Rozali AA, Apun K
    J Environ Public Health, 2018;2018:4592830.
    PMID: 30245728 DOI: 10.1155/2018/4592830
    Introduction: Staphylococcus aureus is a leading cause of cutaneous bacterial infection involving community.

    Methods: In this study, a total of 42 swab samples were collected from the surface of various fitness equipment such as back machines, exercise mats, dip stations, dumbbells, and treadmills. Identification of the bacterial isolates was conducted using biochemical tests and further analysed molecularly using the PCR method targeting nuc gene (270 bp). The nuc gene encodes for the thermonuclease enzyme, a virulent factor of S. aureus.

    Results: The findings showed 31 out of 42 swab samples (73.81%) were positive with S. aureus.

    Conclusion: This study showed that gymnasium equipment is a potential reservoir for S. aureus and might play an important role in transmitting the pathogen to humans.

    Objective: This study was undertaken to assess the presence of S. aureus on the surface of fitness equipment from selected gymnasiums in Kuching and Kota Samarahan, Sarawak (Malaysia).

    Matched MeSH terms: Environmental Microbiology*
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