Displaying publications 321 - 340 of 493 in total

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  1. Saiful Anuar AS, Mohd Yusof MY, Tay ST
    Eur Rev Med Pharmacol Sci, 2013 Jul;17(13):1744-7.
    PMID: 23852897
    The ciprofloxacin resistance of Klebsiella (K.) pneumoniae is mediated primarily through alterations in type II topoisomerase (gyrA) gene and plasmid-mediated quinolone resistance-conferring genes (qnr). This study aimed to define the prevalence of plasmid-mediated quinolone resistance-conferring genes (qnr) and type II topoisomerase (gyrA) alterations of a population of ciprofloxacin-resistant (n = 21), intermediate (n = 8), and sensitive (n = 18) K. pneumoniae isolates obtained from a teaching hospital at Kuala Lumpur, Malaysia.
    Matched MeSH terms: Bacterial Proteins/genetics*
  2. Anbazhagan D, Mansor M, Yan GO, Md Yusof MY, Hassan H, Sekaran SD
    PLoS One, 2012;7(7):e36696.
    PMID: 22815678 DOI: 10.1371/journal.pone.0036696
    Quorum sensing is a term that describes an environmental sensing system that allows bacteria to monitor their own population density which contributes significantly to the size and development of the biofilm. Many gram negative bacteria use N-acyl-homoserine lactones as quorum sensing signal molecules. In this study, we sought to find out if the biofilm formation among clinical isolates of Acinetobacter spp. is under the control of autoinducing quorum sensing molecules.
    Matched MeSH terms: Bacterial Proteins/genetics*
  3. Lim KT, Hanifah YA, Yusof MY, Goering RV, Thong KL
    Diagn Microbiol Infect Dis, 2012 Oct;74(2):106-12.
    PMID: 22770652 DOI: 10.1016/j.diagmicrobio.2012.05.033
    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main bacterial pathogens responsible for nosocomial infections leading to pneumonia, bloodstream, skin, and soft tissue infections. The objective of this study was to investigate the genomic changes of MRSA in a tertiary hospital between the years 2003, 2004, 2007, and 2008. One hundred fifty-four MRSA strains were characterized by multilocus sequence typing (MLST), spa, and mec-associated dru typing. Among the 154 strains, 29 different dru, 15 spa, and 8 MLST types were identified. Seven sequence types (STs) (ST239, ST22, ST5, ST6, ST80, ST573, and ST241) were identified among 2007-08 strains, although only 2 STs (ST239 and ST20) were observed among 2003 strains. Clones ST239-t037-dt13g, ST22-t032-(dt10a and dt10aw), and 28 other MRSA clones being introduced in 2007-2008 have replaced the ST239-t037 (dt13d, 14h, 13i, 13l, 13m, 15m, 15l, and 11al) clones present in 2003. The predominant MLST clone, ST239 (90.3%), was further distinguished into 7 different spa types and 26 different dru types, including 17 novel dru types. Maximum parsimony tree based on dru repeats revealed that 10 dru types (dt11am, dt13j, dt15n, dt13q, dt13n, dt13p, dt13f, dt13ao, dt12j, dt7v) shared the same MLST-spa types with dt13d, suggesting that these MRSA clones might have evolved from ST239-t037-dt13d. In conclusion, our data showed that the ST239-t037-dt13d clone and other MRSA clones in 2003 were replaced by ST239-t037-dt13g and other new emerging spa and dru types.
    Matched MeSH terms: Bacterial Proteins/genetics
  4. Abdelsalam M, Chen SC, Yoshida T
    FEMS Microbiol Lett, 2010 Aug 1;309(1):105-13.
    PMID: 20528946 DOI: 10.1111/j.1574-6968.2010.02024.x
    The Lancefield group C alpha-hemolytic Streptococcus dysgalactiae ssp. dysgalactiae (GCSD) causes systemic granulomatous inflammatory disease and high mortality rates in infected fish. Superantigen and streptolysin S genes are the most important virulence factors contributing to an invasive streptococcal infection. PCR amplification revealed that all strains isolated from moribund fish harbored the streptolysin S structural gene (sagA). GCSD fish isolates were PCR negative for emm, speA, speB, speC, speM, smeZ, and ssa. However, the size of the streptococcal pyrogenic exotoxin G (spegg) locus, a superantigen, in positive S. dysgalactiae fish and pig strains was variable. The ORF of the spegg locus of 26 GCSD fish strains and one GCSD pig strain was inserted with IS981SC. Interestingly, the ORF of the spegg locus of two fish strains of GCSD collected in Malaysia was inserted with an IS981SC-IS1161 hybrid IS element. The hybrid IS element was found in all of the GCSD fish isolates and one GCSD pig through PCR screening. Although no insertion sequence (IS) was detected in the spegg locus of S. dysgalactiae ssp. equisimilis (GCSE) strains, a five-nucleotide deletion mutation was detected in the ORF of the spegg locus of one GCSE strain at the supposed site of IS981SC insertion, resulting in a frameshift mutation.
    Matched MeSH terms: Bacterial Proteins/genetics*
  5. Suppiah J, Thimma JS, Cheah SH, Vadivelu J
    FEMS Microbiol Lett, 2010 May;306(1):9-14.
    PMID: 20345378 DOI: 10.1111/j.1574-6968.2010.01923.x
    Molecular-based techniques are becoming desirable as tools for identification of infectious diseases. Amongst the Burkholderia spp., there is a need to differentiate Burkholderia pseudomallei from Burkholderia cepacia, as misidentification could lead to false treatment of patients. In this study, conventional PCR assay targeting three genes was developed. Primers were designed for the amplification of Burkholderia genus-specific groEL gene, B. pseudomallei-specific mprA gene and B. cepacia-specific zmpA gene. The specificity and sensitivity of the assay was tested with 15 negative control strains and 71 Burkholderia spp. isolates including positive controls B. pseudomallei K96243 and ATCC B. cepacia strain. All B. pseudomallei strains were positive for groEL (139 bp) and mprA (162 bp), indicating a sensitivity of 100%. All B. cepacia strains produced amplicons for detection of groEL and zmpA (147 bp). Specificity using negative strains was 100%. In this study, a PCR assay specific for the detection of Burkholderia spp. and differentiation of the genus B. pseudomallei and B. cepacia was developed. The conventional assay has to be performed separately for each species due to the similar size of the PCR products amplified. This format may therefore be recommended for use as a diagnostic tool in laboratories where real-time PCR machines are not available. However, the real-time PCR was able to detect and differentiate the genus and species in single duplex assay.
    Matched MeSH terms: Bacterial Proteins/genetics
  6. Khoo CH, Cheah YK, Lee LH, Sim JH, Salleh NA, Sidik SM, et al.
    Antonie Van Leeuwenhoek, 2009 Nov;96(4):441-57.
    PMID: 19565351 DOI: 10.1007/s10482-009-9358-z
    The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70% of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration of DNA 0.8 pg microl(-1). This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies.
    Matched MeSH terms: Bacterial Proteins/genetics*
  7. Lalitha P, Siti Suraiya MN, Lim KL, Lee SY, Nur Haslindawaty AR, Chan YY, et al.
    J Microbiol Methods, 2008 Sep;75(1):142-4.
    PMID: 18579241 DOI: 10.1016/j.mimet.2008.05.001
    A PCR assay has been developed based on a lolB (hemM) gene, which was found to be highly conserved among the Vibrio cholerae species but non-conserved among the other enteric bacteria. The lolB PCR detected all O1, O139 and non-O1/non-O139 serogroup and biotypes of V. cholerae. The analytical specificity of this assay was 100% while the analytical sensitivity was 10 pg/microL and 10(3) CFU/mL at DNA and bacterial level respectively. The diagnostic sensitivity and specificity was 98.5% and 100% respectively.
    Matched MeSH terms: Bacterial Proteins/genetics*
  8. Jau MH, Yew SP, Toh PS, Chong AS, Chu WL, Phang SM, et al.
    Int J Biol Macromol, 2005 Aug;36(3):144-51.
    PMID: 16005060
    Three strains of Spirulina platensis isolated from different locations showed capability of synthesizing poly(3-hydroxybutyrate) [P(3HB)] under nitrogen-starved conditions with a maximum accumulation of up to 10 wt.% of the cell dry weight (CDW) under mixotrophic culture conditions. Intracellular degradation (mobilization) of P(3HB) granules by S. platensis was initiated by the restoration of nitrogen source. This mobilization process was affected by both illumination and culture pH. The mobilization of P(3HB) was better under illumination (80% degradation) than in dark conditions (40% degradation) over a period of 4 days. Alkaline conditions (pH 10-11) were optimal for both biosynthesis and mobilization of P(3HB) at which 90% of the accumulated P(3HB) was mobilized. Transmission electron microscopy (TEM) revealed that the mobilization of P(3HB) involved changes in granule quantity and morphology. The P(3HB) granules became irregular in shape and the boundary region was less defined. In contrast to bacteria, in S. platensis the intracellular mobilization of P(3HB) seems to be faster than the biosynthesis process. This is because in cyanobacteria chlorosis delays the P(3HB) accumulation process.
    Matched MeSH terms: Bacterial Proteins/metabolism*
  9. Bilung LM, Radu S, Bahaman AR, Rahim RA, Napis S, Ling MW, et al.
    FEMS Microbiol Lett, 2005 Nov 1;252(1):85-8.
    PMID: 16216442
    This study aimed to determine the occurrence of Vibrio parahaemolyticus in cockles (Anadara granosa) at a harvesting area and to detect the presence of virulent strains carrying the thermostable direct hemolysin (tdh) and TDH-related hemolysin genes (trh) using PCR. Of 100 samples, 62 were positive for the presence of V. parahaemolyticus with an MPN (most probable number) value greater than 3.0 (>1100 MPN per g). The PCR analysis revealed 2 samples to be positive for the tdh gene and 11 to be positive for the trh gene. Hence, these results demonstrate the presence of pathogenic V. parahaemolyticus in cockles harvested in the study area and reveal the potential risk of illness associated with their consumption.
    Matched MeSH terms: Bacterial Proteins/genetics*
  10. Choo SW, Dutta A, Wong GJ, Wee WY, Ang MY, Siow CC
    PLoS One, 2016;11(4):e0150413.
    PMID: 27035710 DOI: 10.1371/journal.pone.0150413
    Mycobacteria have been reported to cause a wide range of human diseases. We present the first whole-genome study of a Non-Tuberculous Mycobacterium, Mycobacterium sp. UM_CSW (referred to hereafter as UM_CSW), isolated from a patient diagnosed with bronchiectasis. Our data suggest that this clinical isolate is likely a novel mycobacterial species, supported by clear evidence from molecular phylogenetic, comparative genomic, ANI and AAI analyses. UM_CSW is closely related to the Mycobacterium avium complex. While it has characteristic features of an environmental bacterium, it also shows a high pathogenic potential with the presence of a wide variety of putative genes related to bacterial virulence and shares very similar pathogenomic profiles with the known pathogenic mycobacterial species. Thus, we conclude that this possible novel Mycobacterium species should be tightly monitored for its possible causative role in human infections.
    Matched MeSH terms: Bacterial Proteins/genetics
  11. Ho WY, Choo QC, Chew CH
    Microb Drug Resist, 2017 Mar;23(2):215-223.
    PMID: 27203527 DOI: 10.1089/mdr.2015.0250
    We investigated the epidemiology and clonality of 175 nonrepetitive methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical specimens collected between 2011 and 2012 in Kinta Valley in Malaysia. Molecular tools such as polymerase chain reaction, pulsed-field gel electrophoresis, and staphylococcal protein A (spa) typing were used. Our study revealed the predominance of three closely related ermA(+) SCCmec type III pulsotypes belonging to spa type t037 (Brazilian-Hungarian clone), which were deficient in the locus F, but positive for the ccrC gene in majority (65.7%) of the MRSA infections in this region. The first evidence of SCCmec type II MRSA in the country, belonging to spa type t2460, was also noted. Although the carriage of pvl gene was uncommon (8.6%) and mostly confined to either SCCmec type IV or SCCmec type V isolates, most of these isolates belonged to spa types t345 or t657, which are associated with the Bengal-Bay CA-MRSA clone. Interestingly, spa t304 and t690 SCCmec type IV pvl(+) were also detected among the MRSA isolates. Data from this study show the rise of uncommon clones among MRSA isolates in Malaysia.
    Matched MeSH terms: Bacterial Proteins/genetics*
  12. Yong AL, Ooh KF, Ong HC, Chai TT, Wong FC
    Food Chem, 2015 Nov 1;186:32-6.
    PMID: 25976788 DOI: 10.1016/j.foodchem.2014.11.103
    In this paper, we investigated the antibacterial mechanism and potential therapeutic targets of three antibacterial medicinal plants. Upon treatment with the plant extracts, bacterial proteins were extracted and resolved using denaturing gel electrophoresis. Differentially-expressed bacterial proteins were excised from the gels and subjected to sequence analysis by MALDI TOF-TOF mass spectrometry. From our study, seven differentially expressed bacterial proteins (triacylglycerol lipase, N-acetylmuramoyl-L-alanine amidase, flagellin, outer membrane protein A, stringent starvation protein A, 30S ribosomal protein s1 and 60 kDa chaperonin) were identified. Additionally, scanning electron microscope study indicated morphological damages induced on bacterial cell surfaces. To the best of our knowledge, this represents the first time these bacterial proteins are being reported, following treatments with the antibacterial plant extracts. Further studies in this direction could lead to the detailed understanding of their inhibition mechanism and discovery of target-specific antibacterial agents.
    Matched MeSH terms: Bacterial Proteins/chemistry*
  13. Babaei M, Sulong A, Hamat R, Nordin S, Neela V
    PMID: 25858356 DOI: 10.1186/s12941-015-0071-7
    Antiseptics are commonly used for the management of MDR (multiple drug resistance) pathogens in hospitals. They play crucial roles in the infection control practices. Antiseptics are often used for skin antisepsis, gauze dressing, preparation of anatomical sites for surgical procedure, hand sterilization before in contact with an infected person, before an invasive procedure and as surgical scrub.
    Matched MeSH terms: Bacterial Proteins/genetics*
  14. Atiya N, Sulaiman H, Chong J, Ng KP
    J Infect Dev Ctries, 2015 Mar;9(3):313-6.
    PMID: 25771471 DOI: 10.3855/jidc.5208
    We report the first case of an immunocompromised adult patient presenting with cervicofacial lymphadenitis due to Mycobacterium haemophilum, confirmed using hsp65 gene sequencing and line-probe assays. In resource-limited settings, especially in developing countries, appropriate culture methods and rapid molecular diagnostic tools such as hsp65 gene sequencing for identification of this organism may not be readily available. This may cause M. haemophilum infections to go unrecognised or lead to delays in diagnosis. Lack of heightened awareness about the potential for this mycobacterial species to cause infections may also contribute to possible underestimation of M. haemophilum cases in the developing world.
    Matched MeSH terms: Bacterial Proteins/genetics
  15. Eshaghi M, Ali AM, Jamal F, Yusoff K
    J. Biochem. Mol. Biol. Biophys., 2002 Feb;6(1):23-8.
    PMID: 12186779
    Streptococcus pyogenes ST4547 is an opacity factor negative strain, which has been recently reported as a new emm type from Malaysia. Nucleotide sequencing of the mga regulon of this strain showed the existence of two emm-like genes. The emm gene located upstream of the scpA gene comprises 1305 nucleotides encoding the putative precursor M protein of 435 amino acids in length with an M(r) of 49 kDa. or a predicted mature protein of 394 amino acids with an M(r) of 44.8 kDa. Another gene mrpST4547 was located upstream of the emm gene and downstream of the mga gene. The sequence of this mrp gene comprises 1167 nucleotides encoding a predicted protein of 388 amino acids in length with an M(r) of 42.2 kDa. or a predicted mature protein of 347 amino acids with an M(r) of 37.9 kDa. The mga regulon of strain ST4547 has a mosaic structure comprising segments, which originated from different OF positive and OF negative strains. The sequences flanking the hyper-variable and C repeats of the emmST4547 gene showed high similarity to corresponding regions in the mga regulon of OF positive strains notably M15, M4, M22 and M50. In contrast, the sequence within the hyper-variable and C repeat regions of the emmST4547 gene revealed high similarity to equivalent regions in the OF negative strains. These data indicates that horizontal transfer of emm-like gene could have occurred between OF positive and OF negative strains resulting in architectural divergence in the mga regulon.
    Matched MeSH terms: Bacterial Proteins*
  16. Song JH, Lee NY, Ichiyama S, Yoshida R, Hirakata Y, Fu W, et al.
    Clin Infect Dis, 1999 Jun;28(6):1206-11.
    PMID: 10451154
    Antimicrobial susceptibility of 996 isolates of Streptococcus pneumoniae from clinical specimens was investigated in 11 Asian countries from September 1996 to June 1997. Korea had the greatest frequency of nonsusceptible strains to penicillin with 79.7%, followed by Japan (65.3%), Vietnam (60.8%), Thailand (57.9%), Sri Lanka (41.2%), Taiwan (38.7%), Singapore (23.1%), Indonesia (21.0%), China (9.8%), Malaysia (9.0%), and India (3.8%). Serotypes 23F and 19F were the most common. Pulsed-field gel electrophoresis (PFGE) of 154 isolates from Asian countries showed several major PFGE patterns. The serotype 23F Spanish clone shared the same PFGE pattern with strains from Korea, Japan, Singapore, Taiwan, Thailand, and Malaysia. Fingerprinting analysis of pbp1a, pbp2x, and pbp2b genes of 12 strains from six countries also showed identical fingerprints of penicillin-binding protein genes in most strains. These data suggest the possible introduction and spread of international epidemic clones into Asian countries and the increasing problems of pneumococcal drug resistance in Asian countries for the first time.
    Matched MeSH terms: Bacterial Proteins*
  17. Jiménez-Castellanos JC, Wan Nur Ismah WAK, Takebayashi Y, Findlay J, Schneiders T, Heesom KJ, et al.
    J Antimicrob Chemother, 2018 Jan 01;73(1):88-94.
    PMID: 29029194 DOI: 10.1093/jac/dkx345
    Objectives: In Klebsiella pneumoniae, overproduction of RamA results in reduced envelope permeability and reduced antimicrobial susceptibility but clinically relevant resistance is rarely observed. Here we have tested whether RamA overproduction can enhance acquired β-lactam resistance mechanisms in K. pneumoniae and have defined the envelope protein abundance changes upon RamA overproduction during growth in low and high osmolarity media.

    Methods: Envelope permeability was estimated using a fluorescent dye accumulation assay. β-Lactam susceptibility was measured using disc testing. Total envelope protein production was quantified using LC-MS/MS proteomics and transcript levels were quantified using real-time RT-PCR.

    Results: RamA overproduction enhanced β-lactamase-mediated β-lactam resistance, in some cases dramatically, without altering β-lactamase production. It increased production of efflux pumps and decreased OmpK35 porin production, though micF overexpression showed that OmpK35 reduction has little impact on envelope permeability. A survey of K. pneumoniae bloodstream isolates revealed ramA hyperexpression in 3 of 4 carbapenemase producers, 1 of 21 CTX-M producers and 2 of 19 strains not carrying CTX-M or carbapenemases.

    Conclusions: Whilst RamA is not a key mediator of antibiotic resistance in K. pneumoniae on its own, it is potentially important for enhancing the spectrum of acquired β-lactamase-mediated β-lactam resistance. LC-MS/MS proteomics analysis has revealed that this enhancement is achieved predominantly through activation of efflux pump production.

    Matched MeSH terms: Bacterial Proteins/biosynthesis*
  18. Ali A, Kumar R, Khan A, Khan AU
    Int J Biol Macromol, 2020 Oct 01;160:212-223.
    PMID: 32464197 DOI: 10.1016/j.ijbiomac.2020.05.172
    Carbapenem resistance in Gram-negative pathogens has become a global concern for health workers worldwide. In one of our earlier studies, a Klebsiella pneumoniae-carbapenemase-2 producing strain was induced with meropenem to explore differentially expressed proteins under induced and uninduced conditions. There is, LysM domain BON family protein, was found over 12-fold expressed under the induced state. A hypothesis was proposed that LysM domain protein might have an affinity towards carbapenem antibiotics making them unavailable to bind with their target. Hence, we initiated a study to understand the binding mode of carbapenem with LysM domain protein. MICs of imipenem and meropenem against LysM clone were increased by several folds as compared to NP-6 clinical strain as well as DH5 α (PET-28a KPC-2) clone. This study further revealed a strong binding of both antibiotics to LysM domain protein. Molecular simulation studies of LysM domain protein with meropenem and imipenem for 80 ns has also showed stable structure. We concluded that overexpressed LysM domain under induced condition interacted with carbapenems, leading to enhanced resistance as proved by high MIC values. Hence, the study proved the proposed hypothesis that the LysM domain plays a significant role in the putative mechanism of antibiotics resistance.
    Matched MeSH terms: Bacterial Proteins/metabolism*
  19. Halim MA, Choo QC, Ghazali AHA, Wajidi MFF, Najimudin N
    Lett Appl Microbiol, 2021 May;72(5):610-618.
    PMID: 33525052 DOI: 10.1111/lam.13455
    Paenibacillus durus strain ATCC 35681T is a Gram-positive diazotroph that displayed capability of fixing nitrogen even in the presence of nitrate or ammonium. However, the nitrogen fixation activity was detected only at day 1 of growth when cultured in liquid nitrogen-enriched medium. The transcripts of all the nifH homologues were present throughout the 9-day study. When grown in nitrogen-depleted medium, nitrogenase activities occurred from day 1 until day 6 and the nifH transcripts were also present during the course of the study albeit at different levels. In both studies, the absence of nitrogen fixation activity regardless of the presence of the nifH transcripts raised the possibility of a post-transcriptional or post-translational regulation of the system. A putative SigA box sequence was found upstream of the transcription start site of nifB1, the first gene in the major nitrogen fixation cluster. The upstream region of nifB2 showed a promoter recognizable by SigE, a sigma factor normally involved in sporulation.
    Matched MeSH terms: Bacterial Proteins/genetics
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