Displaying publications 41 - 60 of 142 in total

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  1. A simplified multiplex PCR assay for fast and easy discrimination of globally distributed staphylococcal cassette chromosome mec types in meticillin-resistant Staphylococcus aureus
    Ghaznavi-Rad E, Nor Shamsudin M, Sekawi Z, van Belkum A, Neela V
    J Med Microbiol, 2010 Oct;59(Pt 10):1135-1139.
    PMID: 20616192 DOI: 10.1099/jmm.0.021956-0
    A multiplex PCR assay was developed for the identification of major types and subtypes of staphylococcal cassette chromosome mec (SCCmec) in meticillin-resistant Staphylococcus aureus (MRSA) strains. The method uses a novel 9 valent multiplex PCR plus two primer pairs for S. aureus identification and detection of meticillin resistance. All 389 clinical MRSA isolates from Malaysia and 18 European isolates from the Harmony collection harbouring different SCCmec types that we tested were correctly characterized by our PCR assay. SCCmec type III and V were by far the most common types among both hospital- and community-acquired Malaysian MRSA isolates, with an apparent emergence of MRSA harbouring the IVh type.
    Matched MeSH terms: Bacterial Typing Techniques*
  2. Fulltext Molecular evidence of cholera outbreak caused by a toxigenic Vibrio cholerae O1 El tor variant strain in Kelantan, Malaysia
    Ang GY, Yu CY, Balqis K, Elina HT, Azura H, Hani MH, et al.
    J Clin Microbiol, 2010 Nov;48(11):3963-9.
    PMID: 20826646 DOI: 10.1128/JCM.01086-10
    A total of 20 Vibrio cholerae isolates were recovered for investigation from a cholera outbreak in Kelantan, Malaysia, that occurred between November and December 2009. All isolates were biochemically characterized as V. cholerae serogroup O1 Ogawa of the El Tor biotype. They were found to be resistant to multiple antibiotics, including tetracycline, erythromycin, sulfamethoxazole-trimethoprim, streptomycin, penicillin G, and polymyxin B, with 35% of the isolates being resistant to ampicillin. All isolates were sensitive to ciprofloxacin, norfloxacin, chloramphenicol, gentamicin, and kanamycin. Multiplex PCR analysis confirmed the biochemical identification and revealed the presence of virulence genes, viz., ace, zot, and ctxA, in all of the isolates. Interestingly, the sequencing of the ctxB gene showed that the outbreak strain harbored the classical cholera toxin gene and therefore belongs to the newly assigned El Tor variant biotype. Clonal analysis by pulsed-field gel electrophoresis demonstrated that a single clone of a V. cholerae strain was responsible for this outbreak. Thus, we present the first molecular evidence that the toxigenic V. cholerae O1 El Tor variant has invaded Malaysia, highlighting the need for continuous monitoring to facilitate early interventions against any potential epidemic by this biotype.
    Matched MeSH terms: Bacterial Typing Techniques
  3. Fulltext Multiple-locus variable-number tandem repeat analysis of Vibrio cholerae in comparison with pulsed field gel electrophoresis and virulotyping
    Teh CS, Chua KH, Thong KL
    J Biomed Biotechnol, 2010;2010:817190.
    PMID: 20671932 DOI: 10.1155/2010/817190
    Molecular analysis of Malaysian Vibrio cholerae was carried out using a multiple-locus variable-number tandem repeat analysis (MLVA) assay based on 7 loci of V. cholerae. The discriminatory ability of the assay was compared with pulsed-field gel electrophoresis (PFGE) using 43 Malaysian V. cholerae isolated from various sources. In addition, the virulotypes of the strains were determined. Based on MLVA, 38 allelic profiles were obtained (F = 0.63) while PFGE generated 35 pulsotypes (F = 0.71). Simpson's index of diversity for different VNTR loci ranged from 0.59 to 0.92. The combined loci increased the discriminatory index to 0.99 which was comparable with PFGE (D = 0.99). Most of the environmental non-O1/non-O139 strains harbored rtxA, rstR, toxR, and hlyA only, and the virulotype of this serogroup was significantly different (P < .01) from clinical/environmental O1 and environmental O139 strains. In conclusion, the MLVA assay developed in this study was a useful genotyping tool with comparable discriminatory power with PFGE. In addition, the combination of the two approaches can further distinguish the strains from different sources and geographical regions of isolation.
    Matched MeSH terms: Bacterial Typing Techniques/methods*
  4. Enhancement of thermostable lipase production by a genotypically identified extremophilic Bacillus subtilis NS 8 in a continuous bioreactor
    Olusesan AT, Azura LK, Abubakar F, Mohamed AK, Radu S, Manap MY, et al.
    J. Mol. Microbiol. Biotechnol., 2011 Apr;20(2):105-15.
    PMID: 21422764 DOI: 10.1159/000324535
    Bacillus strain NS 8, a lipase-producing bacterium isolated from a Malaysian hot spring, is able to tolerate a broad range of temperature and pH, which makes it beneficial for this study. It generated PCR products with molecular weight of 1,532 bp, and the 16S rRNA sequence analysis identified it as Bacillus subtilis with accession number AB110598. It showed a 71% similarity index with B. subtilis using Biolog Microstation System. Its lipase production was optimized using a shake flask system by changing the physical (agitation speed, pH and temperature) and nutritional (nitrogen, carbon and minerals) factors. The most suitable combination of the basal medium for lipase production was 2.5% olive oil (carbon), 1.5% peptone (nitrogen), 0.1% MgSO(4) (mineral) at an optimum temperature of 50°C, pH 7.5 and 150 rpm agitation, giving an enzyme yield of 4.23 U/ml. Statistical optimization using response surface methodology was carried out. An optimum lipase production of 5.67 U/ml was achieved when olive oil concentration of 3%, peptone 2%, MgSO(4)·7H(2)O 0.2% and an agitation rate of 200 rpm were combined. Lipase production was further carried out inside a 2-liter bioreactor, which yielded an enzyme activity of 14.5 U/ml after 15 h of incubation.
    Matched MeSH terms: Bacterial Typing Techniques
  5. Methicillin-susceptible Staphylococcus aureus from clinical and community sources are genetically diverse
    Ghasemzadeh-Moghaddam H, Ghaznavi-Rad E, Sekawi Z, Yun-Khoon L, Aziz MN, Hamat RA, et al.
    Int J Med Microbiol, 2011 Apr;301(4):347-53.
    PMID: 21193348 DOI: 10.1016/j.ijmm.2010.10.004
    Despite the association of methicillin-susceptible S. aureus (MSSA) with several life-threatening diseases, relatively little is known about their clinical epidemiology in Malaysia. We characterized MSSA isolates (n=252) obtained from clinical and community (carriage) sources based on spa sequencing and multilocus sequence typing (MLST). The prevalence of several important virulence genes was determined to further define the molecular characteristics of MSSA clones circulating in Malaysia. Among the 142 clinical and 110 community-acquired MSSA isolates, 98 different spa types were identified, corresponding to 8 different spa clonal clusters (spa-CCs). In addition, MLST analysis revealed 22 sequence types (STs) with 5 singletons corresponding to 12 MLST-CCs. Interestingly, spa-CC084/085 (MLST-CC15) (p=0.038), spa-non-founder 2 (MLST-ST188) (p=0.002), and spa-CC127 (MLST-CC1) (p=0.049) were identified significantly more often among clinical isolates. spa-CC3204 (MLST-CC121) (p=0.02) and spa-CC015 (MLST-CC45) (p=0.0002) were more common among community isolates. Five dominant MLST-CCs (CC8, CC121, CC1, CC45, and CC5) having clear counterparts among the major MRSA clones were also identified in this study. While the MSSA strains are usually genetically heterogeneous, a relatively high frequency (19/7.5%) of ST188 (t189) strains was found, with 57.8% of these strains carrying the Panton-Valentine leukocidin (PVL). Analysis of additional virulence genes showed a frequency of 36.5% and 36.9% for seg and sei and 0.8% and 6.3% for etb and tst genes, respectively. Arginine catabolic mobile element (ACME) was detected in 4 community isolates only. These represent the first isolates harbouring this gene in an Asian region. In conclusion, MSSA from the Malaysian community and their clinical counterparts are genetically diverse, but certain clones occur more often among clinical isolates than among carriage isolates and vice versa.
    Matched MeSH terms: Bacterial Typing Techniques
  6. Fulltext Predominance of ST320 among Streptococcus pneumoniae serotype 19A isolates from 10 Asian countries
    Shin J, Baek JY, Kim SH, Song JH, Ko KS
    J Antimicrob Chemother, 2011 May;66(5):1001-4.
    PMID: 21393143 DOI: 10.1093/jac/dkr048
    BACKGROUND: After 7-valent pneumococcal conjugate vaccine (PCV7) introduction, non-vaccine serotypes such as 19A are increasing among Streptococcus pneumoniae. However, only limited data on 19A S. pneumoniae are available in Asian countries.
    METHODS: Out of 1637 S. pneumoniae clinical pneumonia isolates collected during 2008 and 2009 from 10 Asian countries (Korea, Malaysia, Taiwan, Thailand, Saudi Arabia, Hong Kong, India, Japan, the Philippines and Vietnam), 91 serotype 19A S. pneumoniae isolates were identified. Capsular swelling reaction identified serotype 19A isolates. Antimicrobial susceptibility testing was performed on the serotype 19A isolates using the broth microdilution method, and the genotypes of the isolates were assessed using multilocus sequence typing.
    RESULTS: Thirty different sequence types (STs) were identified. The most prevalent clone was ST320 (46 isolates, 51.1%). ST320 was found in Hong Kong, India, Korea, Malaysia, Saudi Arabia and Taiwan. ST320 isolates were mostly multidrug resistant (MDR) and showed significantly higher resistance rates than other STs for cefuroxime, clindamycin, and trimethoprim/sulfamethoxazole.
    CONCLUSIONS: Although diverse clones were identified among 19A S. pneumoniae isolates, MDR ST320 was the predominant clone in Asian countries. Its predominance, even in countries with no or low coverage of PCV7, may indicate that its emergence and dissemination was due to more than just vaccine selection pressure in Asian countries. A longitudinal investigation of the change of serotypes and genotypes since the introduction of PCV7 is required to understand the emergence and dissemination mechanisms of a certain clone of 19A S. pneumoniae isolates.
    Matched MeSH terms: Bacterial Typing Techniques
  7. Antimicrobial susceptibility and pulsed: field Gel Electrophoretic analysis of Salmonella in a tertiary hospital in northern Malaysia
    Thong KL, Lai WL, Dhanoa A
    J Infect Public Health, 2011 Jun;4(2):65-72.
    PMID: 21663875 DOI: 10.1016/j.jiph.2011.03.003
    Salmonella infections remain a major public health problem in developing countries. The occurrence of infections caused by antimicrobial-resistant Salmonella has been on the rise complicating the available therapeutic options. The study aimed to determine the antibiograms and genotypes of prevalent Salmonella serotypes.
    Matched MeSH terms: Bacterial Typing Techniques*
  8. mec-associated dru typing in the epidemiological analysis of ST239 MRSA in Malaysia
    Ghaznavi-Rad E, Goering RV, Nor Shamsudin M, Weng PL, Sekawi Z, Tavakol M, et al.
    Eur J Clin Microbiol Infect Dis, 2011 Nov;30(11):1365-9.
    PMID: 21479532 DOI: 10.1007/s10096-011-1230-1
    The usefulness of mec-associated dru typing in the epidemiological analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolated in Malaysia was investigated and compared with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and spa and SCCmec typing. The isolates studied included all MRSA types in Malaysia. Multilocus sequence type ST188 and ST1 isolates were highly clonal by all typing methods. However, the dru typing of ST239 isolates produced the clearest discrimination between SCCmec IIIa and III isolates, yielding more subtypes than any other method. Evaluation of the discriminatory power for each method identified dru typing and PFGE as the most discriminatory, with Simpson's index of diversity (SID) values over 89%, including an isolate which was non-typeable by spa, but dru-typed as dt13j. The discriminatory ability of dru typing, especially with closely related MRSA ST239 strains (e.g., Brazilian and Hungarian), underscores its utility as a tool for the epidemiological investigation of MRSA.
    Matched MeSH terms: Bacterial Typing Techniques/methods*
  9. Amycolatopsis thermophila sp. nov. and Amycolatopsis viridis sp. nov., thermophilic actinomycetes isolated from arid soil
    Zucchi TD, Tan GYA, Goodfellow M
    Int J Syst Evol Microbiol, 2012 Jan;62(Pt 1):168-172.
    PMID: 21378137 DOI: 10.1099/ijs.0.029256-0
    The taxonomic positions of two thermophilic actinomycetes isolated from an arid Australian soil sample were established based on an investigation using a polyphasic taxonomic approach. The organisms had chemical and morphological properties typical of members of the genus Amycolatopsis and formed distinct phyletic lines in the Amycolatopsis methanolica 16S rRNA subclade. The two organisms were distinguished from one another and from the type strains of related species of the genus Amycolatopsis using a range of phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the two isolates be classified in the genus Amycolatopsis as Amycolatopsis thermophila sp. nov. (type strain GY088(T)=NCIMB 14699(T)=NRRL B-24836(T)) and Amycolatopsis viridis sp. nov. (type strain GY115(T)=NCIMB 14700(T)=NRRL B-24837(T)).
    Matched MeSH terms: Bacterial Typing Techniques
  10. Fulltext Investigation of toxin genes among methicillin-resistant Staphylococcus aureus strains isolated from a tertiary hospital in Malaysia
    Lim KT, Hanifah YA, Mohd Yusof MY, Thong KL
    Trop Biomed, 2012 Jun;29(2):212-9.
    PMID: 22735842 MyJurnal
    Staphylococcus aureus is a persistent human pathogen responsible for a variety of infections ranging from soft-tissue infections to bacteremia. It produces a variety of virulence factors which are responsible for specific acute staphylococcal toxaemia syndromes. The objective of this study was to determine the prevalence of a repertoire of toxin genes among Malaysian MRSA strains and their genetic diversity by PCR-RFLP of coa gene. One hundred eighty-eight strains (2003, 2004, 2007 and 2008) of methicillin-resistant S. aureus (MRSA) were screened for 20 genes encoding for extracellular virulence determinant (sea, seb, sec, sed, see, seg, seh, sei, sej, tst, eta, etb, etd) and adhesins (cna, etb, fnbA, fnbB, hlg, ica, sdrE). The genetic relatedness of these strains was determined by PCR-RFLP of coa gene and agr grouping. Majority of the strains were tested positive for efb and fnbA (96% each), ica (78%) and hlg (59%) genes. A total of 101 strains were positive for at least one type of staphylococcal enterotoxin genes with sea being the predominant. Genes for seb, sed, see, seh, sej, eta and etb were not detected in any of the MRSA strains. The prevalence of sea, sec and ica among strains isolated in 2008 was increased significantly (p< 0.05) compared to 2003. Most of the strains were of agr type I (97.5%) followed by agr type II (1.2%) and agr type III (0.6%). All sea, sei and tst gene-positive strains were of agr type I. The only etd positive strain was agr type III. PCR-RFLP of coa produced 47 different patterns. The number of strains with virulence factors (sea, sec and ica) had increased over the years. No direct correlation between PCR-RFLP- coa profiles and virulotypes was observed.
    Matched MeSH terms: Bacterial Typing Techniques/methods
  11. Fulltext Outbreak-associated Vibrio cholerae genotypes with identical pulsotypes, Malaysia, 2009
    Teh CS, Suhaili Z, Lim KT, Khamaruddin MA, Yahya F, Sajili MH, et al.
    Emerg Infect Dis, 2012 Jul;18(7):1177-9.
    PMID: 22709679 DOI: 10.3201/eid1807.111656
    A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures.
    Matched MeSH terms: Bacterial Typing Techniques
  12. Fulltext Methicillin sensitive Staphylococcus aureus (MSSA) isolates as a potential source for the emergence of USA 300 methicillin resistant Staphylococcus aureus (MRSA) in Malaysia
    Ghasemzadeh-Moghaddam H, Neela V, Goering R, Mariana NS
    Trop Biomed, 2012 Sep;29(3):429-33.
    PMID: 23018506
    We investigated the potential of USA300 MRSA emergence in Malaysia by examining 268 MSSA isolates from both community (110) and healthcare (158) settings. Nine isolates from both the environments were similar to the USA300 MRSA background based on MLST, spa and PFGE type. These results underscore the importance of continued surveillance to monitor the emergence of USA300 MRSA in Malaysia.
    Matched MeSH terms: Bacterial Typing Techniques
  13. Fulltext Genomic Analysis of Mycobacterium massiliense strain M115, an isolate from human sputum
    Ngeow YF, Wong YL, Lokanathan N, Wong GJ, Ong CS, Ng KP, et al.
    J Bacteriol, 2012 Sep;194(17):4786.
    PMID: 22887681 DOI: 10.1128/JB.01104-12
    We report the draft genome sequence of a clinical isolate, strain M115, identified as Mycobacterium massiliense, a member of the newly created taxon of Mycobacterium abscessus subspecies bolletii comb. nov.
    Matched MeSH terms: Bacterial Typing Techniques
  14. Fulltext Annotated genome sequence of Mycobacterium massiliense strain M154, belonging to the recently created taxon Mycobacterium abscessus subsp. bolletii comb. nov
    Choo SW, Wong YL, Tan JL, Ong CS, Wong GJ, Ng KP, et al.
    J Bacteriol, 2012 Sep;194(17):4778.
    PMID: 22887675 DOI: 10.1128/JB.01043-12
    Mycobacterium massiliense has recently been proposed as a member of Mycobacterium abscessus subsp. bolletii comb. nov. Strain M154, a clinical isolate from the bronchoalveolar lavage fluid of a Malaysian patient presenting with lower respiratory tract infection, was subjected to shotgun DNA sequencing with the Illumina sequencing technology to obtain whole-genome sequence data for comparison with other genetically related strains within the M. abscessus species complex.
    Matched MeSH terms: Bacterial Typing Techniques
  15. Paracoccus rhizosphaerae sp. nov., isolated from the rhizosphere of the plant Crossostephium chinense (L.) Makino (Seremban)
    Kämpfer P, Lai WA, Arun AB, Young CC, Rekha PD, Martin K, et al.
    Int J Syst Evol Microbiol, 2012 Nov;62(Pt 11):2750-2756.
    PMID: 22286908 DOI: 10.1099/ijs.0.039057-0
    A Gram-negative, coccoid-shaped bacterium, strain CC-CCM15-8(T), was isolated from a rhizosphere soil sample of the plant Crossostephium chinense (L.) Makino (Seremban) from Budai Township, Chiayi County, Taiwan. 16S rRNA gene sequence analysis clearly allocated strain CC-CCM15-8(T) to the Paracoccus cluster, showing highest similarities to the type strains of 'Paracoccus beibuensis' (98.8%), Paracoccus homiensis (97.6%), Paracoccus aestuarii (97.7%) and Paracoccus zeaxanthinifaciens (97.7%). The fatty acid profile, comprising C(18:1)ω7c as the major component and C(10:0) 3-OH as the characteristic hydroxylated fatty acid, supported the placement of strain CC-CCM15-8(T) within the genus Paracoccus. The polyamine pattern consisted of putrescine and spermidine as major components. Ubiqinone Q-10 was the major quinone type (95%); ubiquinone Q-9 was also detected (5%). The complex polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and unidentified phospholipids, lipids and glycolipids. Levels of DNA-DNA relatedness between strain CC-CCM15-8(T) and 'P. beibuensis' LMG 25871(T), P. aestuarii DSM 19484(T), P. zeaxanthinifaciens LMG 21993(T) and P. homiensis KACC 11518(T) were 24.9% (34.8%, reciprocal analysis), 15.7% (17.5%), 17.7% (23.4%) and 16.0% (25.4%), respectively. Physiological and biochemical test results allowed the phenotypic differentiation of strain CC-CCM15-8(T) from its closest relatives in the genus Paracoccus. Based on the data presented, it is concluded that strain CC-CCM15-8(T) represents a novel species of the genus Paracoccus, for which the name Paracoccus rhizosphaerae sp. nov. is proposed. The type strain is CC-CCM15-8(T) (=LMG 26205(T)=CCM 7904(T)).
    Matched MeSH terms: Bacterial Typing Techniques
  16. Fulltext Characterization of Shigella sonnei in Malaysia, an increasingly prevalent etiologic agent of local shigellosis cases
    Koh XP, Chiou CS, Ajam N, Watanabe H, Ahmad N, Thong KL
    BMC Infect Dis, 2012;12:122.
    PMID: 22606962 DOI: 10.1186/1471-2334-12-122
    Shigellosis is a major public health concern worldwide, especially in developing countries. It is an acute intestinal infection caused by bacteria of the genus Shigella, with a minimum infective dose as low as 10-100 bacterial cells. Increasing prevalence of Shigella sonnei as the etiologic agent of shigellosis in Malaysia has been reported. As there is limited information on the genetic background of S. sonnei in Malaysia, this study aimed to characterize Malaysian S. sonnei and to evaluate the prospect of using multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for subtyping of local S. sonnei.
    Matched MeSH terms: Bacterial Typing Techniques
  17. Fulltext Molecular characterization of clinical isolates of Aeromonas species from Malaysia
    Puthucheary SD, Puah SM, Chua KH
    PLoS One, 2012;7(2):e30205.
    PMID: 22383958 DOI: 10.1371/journal.pone.0030205
    BACKGROUND: Aeromonas species are common inhabitants of aquatic environments giving rise to infections in both fish and humans. Identification of aeromonads to the species level is problematic and complex due to their phenotypic and genotypic heterogeneity.

    METHODOLOGY/PRINCIPAL FINDINGS: Aeromonas hydrophila or Aeromonas sp were genetically re-identified using a combination of previously published methods targeting GCAT, 16S rDNA and rpoD genes. Characterization based on the genus specific GCAT-PCR showed that 94 (96%) of the 98 strains belonged to the genus Aeromonas. Considering the patterns obtained for the 94 isolates with the 16S rDNA-RFLP identification method, 3 clusters were recognised, i.e. A. caviae (61%), A. hydrophila (17%) and an unknown group (22%) with atypical RFLP restriction patterns. However, the phylogenetic tree constructed with the obtained rpoD sequences showed that 47 strains (50%) clustered with the sequence of the type strain of A. aquariorum, 18 (19%) with A. caviae, 16 (17%) with A. hydrophila, 12 (13%) with A. veronii and one strain (1%) with the type strain of A. trota. PCR investigation revealed the presence of 10 virulence genes in the 94 isolates as: lip (91%), exu (87%), ela (86%), alt (79%), ser (77%), fla (74%), aer (72%), act (43%), aexT (24%) and ast (23%).

    CONCLUSIONS/SIGNIFICANCE: This study emphasizes the importance of using more than one method for the correct identification of Aeromonas strains. The sequences of the rpoD gene enabled the unambiguous identication of the 94 Aeromonas isolates in accordance with results of other recent studies. Aeromonas aquariorum showed to be the most prevalent species (50%) containing an important subset of virulence genes lip/alt/ser/fla/aer. Different combinations of the virulence genes present in the isolates indicate their probable role in the pathogenesis of Aeromonas infections.

    Matched MeSH terms: Bacterial Typing Techniques*
  18. Fulltext Isolation of Pediococcus acidilactici Kp10 with ability to secrete bacteriocin-like inhibitory substance from milk products for applications in food industry
    Abbasiliasi S, Tan JS, Ibrahim TA, Ramanan RN, Vakhshiteh F, Mustafa S, et al.
    BMC Microbiol, 2012;12:260.
    PMID: 23153191 DOI: 10.1186/1471-2180-12-260
    Lactic acid bacteria (LAB) can be isolated from traditional milk products. LAB that secrete substances that inhibit pathogenic bacteria and are resistant to acid, bile, and pepsin but not vancomycin may have potential in food applications.
    Matched MeSH terms: Bacterial Typing Techniques
  19. Fulltext Prevalence of adhesion and regulation of biofilm-related genes in different clones of Staphylococcus aureus
    Atshan SS, Nor Shamsudin M, Sekawi Z, Lung LT, Hamat RA, Karunanidhi A, et al.
    J Biomed Biotechnol, 2012;2012:976972.
    PMID: 22701309 DOI: 10.1155/2012/976972
    Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA), a microtiter plate assay (MPA), polymerase chain reaction (PCR), and reverse transcriptase polymerase chain reaction (RT-PCR). Clones belonging to the same spa type were found to have similar properties in adheringto the polystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes). icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC) was confirmed by RT-PCR.
    Matched MeSH terms: Bacterial Typing Techniques
  20. Fulltext Comparative characterisation of genotypically different clones of MRSA in the production of biofilms
    Atshan SS, Shamsudin MN, Lung LT, Sekawi Z, Ghaznavi-Rad E, Pei CP
    J Biomed Biotechnol, 2012;2012:417247.
    PMID: 22529705 DOI: 10.1155/2012/417247
    The ability to adhere and produce biofilms is characteristic of enhanced virulence among isolates of methicillin-resistant Staphylococcus aureus (MRSA). The aim of the study is to find out whether these characteristics are consistently similar among isolates variations of MRSA. The study used 30 various isolates of MRSA belong to 13 spa types and 5 MLST types and determined the aggregation, the adherence, and the production of biofilms and slime for each isolate. The methods used to evaluate these characteristics were a modified Congo red agar assay (MCRA), a microtiter plate assay (MPA), high-magnification light microscopy, scanning electron microscopy (SEM), and PCR. The study found that isolates belonging to similar Spa, SCCmec, and ST types have similar abilities to produce biofilms; however, their ability to produce slime on CRA was found to be different. Moreover, isolates that have different Spa types showed high variation in their ability to produce biofilms. The results of light microscope revealed the isolates that produced strong and weak biofilms and formed similar aggregation on the glass surfaces. SEM results showed that all 30 MRSA isolates that were tested were 100% positive for biofilm formation, although to varying degrees. Further testing using PCR confirmed that 100% of the 30 isolates tested were positive for the presence of the icaADBC, fnbA, eno, ebps, clfA, and clfB genes. The prevalence of fib, cna, fnbB, and bbp in MRSA clones was 90, 93.33, 53.33, and 10%, respectively. This study indicate that differences in biofilm production capacities are caused by the differences in surface protein A (Spa) type and are not due to differences in MLST and SCCmec types.
    Matched MeSH terms: Bacterial Typing Techniques
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