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  1. 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: Bacterial Proteins/analysis*
  2. Helicobacter pylori: molecular detection of vacA gene and vacuolating activity in human gastric adenocarcinoma cells
    Alfizah H, Noraziah MZ, Chao MY, Rahman MM, Ramelah M
    Clin Ter, 2013;164(4):301-5.
    PMID: 24045512 DOI: 10.7417/CT.2013.1577
    Helicobacter pylori strains secrete a vacuolating cytotoxin (VacA), plays an important role for the development of peptic ulcer disease and gastro-duodenal diseases. vacA gene is responsible to regulate the activity of the vacuolating cytotoxin. The objective of this study was molecular detection of vacA gene and observes the vacuolating activity on human gastric adenocarcinoma (AGS) cells.
    Matched MeSH terms: Bacterial Proteins/analysis
  3. Identification of immunoreactive secretory proteins from the stationary phase culture of Burkholderia pseudomallei
    Vellasamy KM, Mariappan V, Hashim OH, Vadivelu J
    Electrophoresis, 2011 Jan;32(2):310-20.
    PMID: 21254130 DOI: 10.1002/elps.201000355
    Bacterial secreted proteins are known to be involved in virulence and may mediate important host-pathogen interactions. In this study, when the stationary phase culture supernatant of Burkholderia pseudomallei was subjected to 2-DE, 113 protein spots were detected. Fifty-four of the secreted proteins, which included metabolic enzymes, transcription/translation regulators, potential virulence factors, chaperones, transport regulators, and hypothetical proteins, were identified using MS and database search. Twelve of these proteins were apparently reactive to antisera of mice that were immunised with B. pseudomallei secreted proteins. These proteins might be excellent candidates to be used as diagnostic markers or putative candidate vaccines against B. pseudomallei infections.
    Matched MeSH terms: Bacterial Proteins/analysis
  4. Optimization of soy protein isolate, microbial transglutaminase and glucono-δ-lactone in gluten-free rice noodles
    Ojukwu M, Ofoedu C, Seow EK, Easa AM
    J Sci Food Agric, 2021 Jul;101(9):3732-3741.
    PMID: 33301191 DOI: 10.1002/jsfa.11004
    BACKGROUND: Rice flour does not contain gluten and lacks cohesion and extensibility, which is responsible for the poor texture of rice noodles. Different technologies have been used to mitigate this challenge, including hydrothermal treatments of rice flour, direct addition of protein in noodles, use of additives such as hydrocolloids and alginates, and microbial transglutaminase (MTG). Recently, the inclusion of soy protein isolate (SPI), MTG, and glucono-δ-lactone (GDL) in the rice noodles system yielded rice noodles with improved texture and more compact microstructure, hence the need to optimize the addition of SPI, MTG, and GDL to make quality rice noodles.

    RESULTS: Numerical optimization showed that rice noodles prepared with SPI, 68.32 (g kg-1 of rice flour), MTG, 5.06 (g kg-1 of rice flour) and GDL, 5.0 (g kg-1 of rice flour) gave the best response variables; hardness (53.19 N), springiness (0.76), chewiness (20.28 J), tensile strength (60.35 kPa), and cooking time (5.15 min). The pH, sensory, and microstructure results showed that the optimized rice noodles had a more compact microstructure with fewer hollows, optimum pH for MTG action, and overall sensory panelists also showed the highest preference for the optimized formulation, compared to other samples selected from the numerical optimization and desirability tests.

    CONCLUSION: Optimization of the levels of SPI, MTG, and GDL yielded quality noodles with improved textural, mechanical, sensory, and microstructural properties. This was partly due to the favourable pH value of the optimized noodles that provided the most suitable conditions for MTG crosslinking and balanced electrostatic interaction of proteins. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Bacterial Proteins/analysis*
  5. Comparison of aqueous soluble proteins profile of Mycobacterium tuberculosis H37Rv and H37Ra and a Malaysian clinical isolate
    Kai-Cheen A, Lay-Harn G
    Biotechnol Appl Biochem, 2018 Nov;65(6):876-882.
    PMID: 30132993 DOI: 10.1002/bab.1687
    Differentially expressed aqueous soluble proteins between Mycobacterium tuberculosis H37Ra and H37Rv were identified. The protein extracts were separated by two-dimensional gel electrophoresis followed by tandem mass spectrometric analysis. Twelve proteins were detected to be differentially expressed significantly between virulent strain H37Rv and attenuated strain H37Ra. The differentially expression of these proteins was validated by a recently isolated clinical virulent strains of M. tuberculosis, TB138. Out of the 12 proteins identified, which consisted of ten upregulated and two downregulated proteins, nine were belonged to intermediate metabolism and respiration protein group, two were in lipid metabolism, and one protein was involved in information pathways and virulence. Among these proteins, two of the upregulated proteins, namely, mmsA and pntAa, showed a consistent expression pattern in both virulent mycobacterium strains. These proteins can serve as potential biomarkers for the intervention treatment of TB.
    Matched MeSH terms: Bacterial Proteins/analysis*
  6. 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: Bacterial Proteins/analysis
  7. Portable electrochemical immunosensor for detection of Mycobacterium tuberculosis secreted protein CFP10-ESAT6 in clinical sputum samples
    Mohd Azmi UZ, Yusof NA, Abdullah J, Alang Ahmad SA, Mohd Faudzi FN, Ahmad Raston NH, et al.
    Mikrochim Acta, 2021 01 06;188(1):20.
    PMID: 33404779 DOI: 10.1007/s00604-020-04669-x
    An early detection of Mycobacterium tuberculosis is very important to reduce the number of fatal cases and allow for fast recovery. However, the interpretation of the result from smear microscopy requires skilled personnel due to the propensity of the method to produce false-negative results. In this work, a portable, rapid, and simple sandwich-type immunosensor reader has been developed that is able to detect the presence of M. tuberculosis in sputum samples. By using sandwich-type immunosensor, an anti-CFP10-ESAT6 antibody was immobilized onto the graphene/polyaniline (GP/PANI)-modified gold screen-printed electrode. After incubation with the target CFP10-ESAT6 antigen, the iron/gold magnetic nanoparticles (Fe3O4/Au MNPs) conjugated with anti-CFP10-ESAT6 antibody were used to complete the sandwich format. Differential pulse voltammetry (DPV) technique was used to detect the CFP10-ESAT6 antigen at the potential range of 0.0-1.0 V. The detection time is less than 2 h. Under optimal condition, CFP10-ESAT6 antigen was detected in a linear range from 10 to 500 ng mL-1 with a limit of detection at 1.5 ng mL-1. The method developed from this process was then integrated into a portable reader. The performance of the sensor was investigated and compared with the standard methods (culture and smear microscopy). It provides a good correlation (100% sensitivity and 91.7% specificity) with both methods of detection for M. tuberculosis in sputum samples henceforth, demonstrating the potential of the device as a more practical screening tool.Graphical abstract.
    Matched MeSH terms: Bacterial Proteins/analysis*
  8. Fulltext Colonisation factors amongst clinical isolates of enterotoxigenic Escherichia coli
    Iyer L, Vadivelu J, Parasakthi N
    Singapore Med J, 1995 Oct;36(5):495-7.
    PMID: 8882532
    The production of heat-labile (LT) and heat-stable (ST) enterotoxins, colonisation factor antigens (CFAs) and haemagglutinins was investigated amongst 310 Escherichia coli (E. coli) isolates obtained from 62 children under the age of five, with diarrhoea. Twenty-one isolates were found to produce enterotoxins, of which fifteen (71%) isolates produced ST only, 2 (10%) produced LT only and 4 (19%) produced both LT and ST. However, none of the isolates demonstrated any of the common CFAs identified to date, but 8 out of the 21 isolates demonstrated haemagglutination with rabbit, sheep or human group A erythrocytes, suggesting the presence of putative CFAs, yet unidentified.
    Matched MeSH terms: Bacterial Proteins/analysis*
  9. Fulltext Profiling of Burkholderia cepacia secretome at mid-logarithmic and early-stationary phases of growth
    Mariappan V, Vellasamy KM, Hashim OH, Vadivelu J
    PLoS One, 2011;6(10):e26518.
    PMID: 22046299 DOI: 10.1371/journal.pone.0026518
    Burkholderia cepacia is a Gram-negative pathogen that causes serious respiratory infections in immunocompromised patients and individuals with cystic fibrosis. This bacterium is known to release extracellular proteins that may be involved in virulence.
    Matched MeSH terms: Bacterial Proteins/analysis*
  10. Fulltext Complete genome and proteome of Acholeplasma laidlawii
    Lazarev VN, Levitskii SA, Basovskii YI, Chukin MM, Akopian TA, Vereshchagin VV, et al.
    J Bacteriol, 2011 Sep;193(18):4943-53.
    PMID: 21784942 DOI: 10.1128/JB.05059-11
    We present the complete genome sequence and proteogenomic map for Acholeplasma laidlawii PG-8A (class Mollicutes, order Acholeplasmatales, family Acholeplasmataceae). The genome of A. laidlawii is represented by a single 1,496,992-bp circular chromosome with an average G+C content of 31 mol%. This is the longest genome among the Mollicutes with a known nucleotide sequence. It contains genes of polymerase type I, SOS response, and signal transduction systems, as well as RNA regulatory elements, riboswitches, and T boxes. This demonstrates a significant capability for the regulation of gene expression and mutagenic response to stress. Acholeplasma laidlawii and phytoplasmas are the only Mollicutes known to use the universal genetic code, in which UGA is a stop codon. Within the Mollicutes group, only the sterol-nonrequiring Acholeplasma has the capacity to synthesize saturated fatty acids de novo. Proteomic data were used in the primary annotation of the genome, validating expression of many predicted proteins. We also detected posttranslational modifications of A. laidlawii proteins: phosphorylation and acylation. Seventy-four candidate phosphorylated proteins were found: 16 candidates are proteins unique to A. laidlawii, and 11 of them are surface-anchored or integral membrane proteins, which implies the presence of active signaling pathways. Among 20 acylated proteins, 14 contained palmitic chains, and six contained stearic chains. No residue of linoleic or oleic acid was observed. Acylated proteins were components of mainly sugar and inorganic ion transport systems and were surface-anchored proteins with unknown functions.
    Matched MeSH terms: Bacterial Proteins/analysis
  11. Fulltext Immuno Nanosensor for the Ultrasensitive Naked Eye Detection of Tuberculosis
    Mohd Bakhori N, Yusof NA, Abdullah J, Wasoh H, Md Noor SS, Ahmad Raston NH, et al.
    Sensors (Basel), 2018 Jun 14;18(6).
    PMID: 29899214 DOI: 10.3390/s18061932
    In the present study, a beneficial approach for the ultrasensitive and affordable naked eye detection and diagnosis of tuberculosis (TB) by utilizing plasmonic enzyme-linked immunosorbent assay (ELISA) via antibody-antigen interaction was studied. Here, the biocatalytic cycle of the intracellular enzymes links to the formation and successive growth of the gold nanoparticles (GNPs) for ultrasensitive detection. The formation of different colored solutions by the plasmonic nanoparticles in the presence of enzyme labels links directly to the existence or non-existence of the TB analytes in the sample solutions. For disease detection, the adapted protocol is based mainly on the conventional ELISA procedure that involves catalase-labeled antibodies, i.e., the enzymes consume hydrogen peroxide and further produce GNPs with the addition of gold (III) chloride. The amount of hydrogen peroxide remaining in the solution determines whether the GNPs solution is to be formed in the color blue or the color red, as it serves as a confirmation for the naked eye detection of TB analytes. However, the conventional ELISA method only shows tonal colors that need a high concentration of analyte to achieve high confidence levels for naked eye detection. Also, in this research, we proposed the incorporation of protein biomarker, Mycobacterium tuberculosis ESAT-6-like protein esxB (CFP-10), as a means of TB detection using plasmonic ELISA. With the use of this technique, the CFP-10 detection limit can be lowered to 0.01 µg/mL by the naked eye. Further, our developed technique was successfully tested and confirmed with sputum samples from patients diagnosed with positive TB, thereby providing enough evidence for the utilization of our technique in the early diagnosis of TB disease.
    Matched MeSH terms: Bacterial Proteins/analysis*
  12. Fulltext Host-Adaptation of Burkholderia pseudomallei Alters Metabolism and Virulence: a Global Proteome Analysis
    Mariappan V, Vellasamy KM, Vadivelu J
    Sci Rep, 2017 08 21;7(1):9015.
    PMID: 28827633 DOI: 10.1038/s41598-017-09373-0
    Little is known about the evolution, adaptation and pathogenesis of Burkholderia pseudomallei within host during acute melioidosis infection. Melioidosis is a potential life threatening disease contracted through inhalation, ingestion, inoculation or direct entry of the organism into the blood stream via wounds or skin abrasions from contaminated soil and water. Environmental B. pseudomallei strain (Bp MARAN ), isolated during a melioidosis outbreak in Pahang, Malaysia was injected intra-peritoneally into a mouse and passaged strain was recovered from spleen (Bpmouse-adapted). A gel-based comparative proteomics profiling approach was used, to map and identify differentially expressed proteins (fold-change ≥ 2; p-value ≤ 0.05) between the strains. A total of 730 and 685 spots were visualised in the Bp MARAN and Bpmouse-adapted strains, respectively. Of the 730 spots (Bp MARAN as reference gel), 87 spots were differentially regulated (44 up- and 43 down-regulated). The identified proteins were classified as proteins related to metabolism, stress response, virulence, signal transduction, or adhesion. In comparison, it was found that those proteins related to adhesins, virulence factors and stress- response were up-regulated and could possibly explain the adaptation of the bacteria in the host. Investigating the differentially expressed proteins may provide better perspective of bacterial factors which aid survivability of B. pseudomallei in host.
    Matched MeSH terms: Bacterial Proteins/analysis*
  13. Additional oligofructose/inulin does not increase faecal bifidobacteria in critically ill patients receiving enteral nutrition: a randomised controlled trial
    Majid HA, Cole J, Emery PW, Whelan K
    Clin Nutr, 2014 Dec;33(6):966-72.
    PMID: 24290345 DOI: 10.1016/j.clnu.2013.11.008
    Patients with diarrhoea during enteral nutrition (EN) have been shown to have low faecal bifidobacteria concentrations. Oligofructose/inulin selectively stimulate the growth of bifidobacteria in healthy humans. This study investigates the effect of additional oligofructose/inulin on the gastrointestinal microbiota, short-chain fatty acids (SCFA) and faecal output in patients receiving EN.
    Matched MeSH terms: Bacterial Proteins/analysis
  14. Fulltext Prevalence of Clostridium difficile toxin in diarhoeal stool samples of patients from a tertiary hospital in North Eastern Penisular Malaysia
    Hassan SA, Othman N, Idris FM, Abdul Rahman Z, Maning N, Abdul Rahman R, et al.
    Med J Malaysia, 2012 Aug;67(4):402-5.
    PMID: 23082450 MyJurnal
    This study describes the prevalence of Clostridium difficile toxin (CDT) in loose stool samples from inpatients aged more than two years of a tertiary hospital. A total of 175 samples that had been examined were from stool samples that were sent to the Medical Microbiology & Parasitology Laboratory for various clinical indications. The toxin was detected by a commercial immunochromatograhic test, and the patients' demography, clinical features, treatment and outcomes were analyzed from their medical records. Clostridium difficile toxin was positive in 24 (13.7%) of the stool samples. Male and female were 11 (45.8%) and 13 (54.2%) respectively, with the majority of them aged more than 50 years. Most were from medical wards (n = 21, 87.5%), with the rest from surgical wards (n = 2, 8.3%) and intensive care units (n = 1, 3.4%). All the CDT positive patients had history of prior antibiotic usage within 6 weeks before the detection of the toxin. The mean duration of antibiotics usage was 17.75 (+/- 13.75) days, while the mean duration of diarrhea was 5.21((+/- 5.85) days. Eighteen patients had underlying medical illnesses that were diabetes mellitus, chronic renal disease, hypertension, ischaemic heart disease, cerebrovascular disease and malignancy; with seven of them being CDT positive while on chemotherapy. Stool occult blood test was positive in 15 patients whereas presence of pus cells in the CD positive stool samples were detected in 21 patients. The duration of hospitalization among the patients was 27.96 (+/- 23.22) days.
    Matched MeSH terms: Bacterial Proteins/analysis*
  15. Fulltext Phenotypic and genetic characterizations of Streptococcus dysgalactiae strains isolated from fish collected in Japan and other Asian countries
    Abdelsalam M, Chen SC, Yoshida T
    FEMS Microbiol Lett, 2010 Jan;302(1):32-8.
    PMID: 19895643 DOI: 10.1111/j.1574-6968.2009.01828.x
    Lancefield group C Streptococcus dysgalactiae is an emerging fish pathogen, which was first isolated in 2002 in Japan. Streptococcus dysgalactiae isolates collected from diseased fish in Japan (n=12), Taiwan (n=12), China (n=2), Malaysia (n=3), and Indonesia (n=1) were characterized using biased sinusoidal field gel electrophoresis (BSFGE), sodA gene sequence analysis, and antimicrobial susceptibility. These isolates exhibited high phenotypic homogeneity irrespective of the countries from where the strains were collected. Seventeen isolates were found to be resistant to oxytetracycline and carried the tet(M) gene, except for the strains collected in Taiwan and the PP1564 strain collected in China. The sodA gene sequence analysis revealed that 23 isolates were identical, except for one Japanese isolate (KNH07902), in which a single nucleotide differed from that of the other isolates. Based on BSFGE typing by ApaI macrorestriction, the isolates - including the Japanese, Taiwanese, and Chinese isolates - could be grouped into one main cluster at a 70% similarity level. However, the macrorestriction genotypes of some isolates were apparently distinct from those of the main cluster.
    Matched MeSH terms: Bacterial Proteins/analysis
  16. Fulltext Understanding the dimorphic lifestyles of human gastric pathogen Helicobacter pylori using the SWATH-based proteomics approach
    Loke MF, Ng CG, Vilashni Y, Lim J, Ho B
    Sci Rep, 2016 05 25;6:26784.
    PMID: 27222005 DOI: 10.1038/srep26784
    Helicobacter pylori may reside in the human stomach as two morphological forms: the culturable spiral form and the viable but non-culturable (VBNC) coccoid form. This bacterium transforms from spiral to coccoid under in vitro suboptimal conditions. However, both spiral and coccoid have demonstrated its infectivity in laboratory animals, suggesting that coccoid may potentially be involved in the transmission of H. pylori. To determine the relevance of the coccoid form in viability and infectivity, we compared the protein profiles of H. pylori coccoids obtained from prolonged (3-month-old) culture with that of 3-day-old spirals of two H. pylori standard strains using SWATH (Sequential Window Acquisition of all Theoretical mass spectra)-based approach. The protein profiles reveal that the coccoids retained basal level of metabolic proteins and also high level of proteins that participate in DNA replication, cell division and biosynthesis demonstrating that coccoids are viable. Most interestingly, these data also indicate that the H. pylori coccoids possess higher level of proteins that are involved in virulence and carcinogenesis than their spiral counterparts. Taken together, these findings have important implications in the understanding on the pathogenesis of H. pylori-induced gastroduodenal diseases, as well as the probable transmission mode of this bacterium.
    Matched MeSH terms: Bacterial Proteins/analysis*
  17. Characterization of the SF agent, an Ehrlichia sp. isolated from the fluke Stellantchasmus falcatus, by 16S rRNA base sequence, serological, and morphological analyses
    Wen B, Rikihisa Y, Yamamoto S, Kawabata N, Fuerst PA
    Int. J. Syst. Bacteriol., 1996 Jan;46(1):149-54.
    PMID: 8573488
    The organism designated the SF agent was originally isolated in Japan in 1962 from Stellantchasmus falcatus metacercaria parasitic on gray mullet fish. The SF agent resembles members of the genus Ehrlichia morphologically and exhibits weak antigenic cross-reactivity with Ehrlichia sennetsu. This organism causes mild clinical signs in dogs, but severe splenomegaly and lymphadenopathy in mice. This suggests that the SF agent may be similar to either Neorickettsia helminthoeca, an intracellular parasite of a fluke and the cause of salmon poisoning disease in dogs, or E. sennetsu, the causative agent of human sennetsu ehrlichiosis in Japan and Malaysia. In order to determine the phylogenetic relationship between the SF agent and other ehrlichial species, the 16S rRNA gene was amplified by the PCR and sequenced. The SF agent sequence was most closely related to the sequences of Ehrlichia risticii (level of sequence similarity, 99.1%), the causative agent of Potomac horse fever, and E. sennetsu (level of sequence similarity, 98.7%). The next most similar sequence was that of N. helminthoeca, but the level of sequence similarity was only 93.7%. E. sennetsu, E. risticii, the SF agent, and N. helminthoeca formed a distinct cluster that was separated from all other ehrlichial species. As determined by immunofluorescence labeling, antiserum against the SF agent cross-reacted strongly with E. sennetsu, E. risticii, and N. helminthoeca. When three genetically distinct ehrlichial isolates obtained from horses with Potomac horse fever were compared with the SF agent, we found that the SF agent was most closely related to Ohio isolate 081, followed by IllinoisT (T = type strain) and a Kentucky isolate. We observed strong antigenic cross-reactivities and similarities in Western blot (immunoblot) reaction profiles when we compared the SF agent, E. risticii, and E. sennetsu; however, weaker antigenic cross-reactivity was observed when the SF agent and N. helminthoeca were compared. Our results indicate that the SF agent is antigenically more closely related to E. risticii and E. sennetsu than to N. helminthoeca. The biological and antigenic characteristics and the 16S rRNA sequence data suggest that the SF agent is a new species that belongs to the genus Ehrlichia.
    Matched MeSH terms: Bacterial Proteins/analysis
  18. Characterization of group A streptococci isolated in Kuala Lumpur, Malaysia
    Jamal F, Pit S, Johnson DR, Kaplan EL
    J Trop Med Hyg, 1995 Oct;98(5):343-6.
    PMID: 7563264
    T-agglutination patterns of 190 strains of group A streptococci isolated between January 1989 and December 1993 from body fluids (10), throat culture (56), pus (51) and skin lesions (73) were determined. Mucoid colonial morphology was exhibited by 6.3% (12/190) of the strains on initial isolation. Type T-5,11,27,44 comprised 23.7%, followed by T-1,3,13,B3264 (11.1%), T-4,6 (8.4%) and T-8,25, Imp 19 (7.9%). About 42% (80/190) strains could not be characterized by T agglutination pattern. T-typing of 71 selected strains at WHO Collaborating Center, Minneapolis yielded similar results. Nineteen selected strains were further characterized by M-typing; only three strains were M-typeable. These strains were isolated from throat (M1), sputum (M5) and pus (M12). About 68% (48/71) isolates produced serum opacity factor. These data support the existence of as yet uncharacterized group A streptococcal serotypes in this region.
    Matched MeSH terms: Bacterial Proteins/analysis
  19. Fulltext A simple screening test for the detection of metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter in a tertiary care hospital
    Wan Nor Amilah WA, Noor Izani NJ, Ng WK, Ashraful Haq J
    Trop Biomed, 2012 Dec;29(4):588-97.
    PMID: 23202604
    Clinical utilization of carbapenems remains under threat with the emergence of acquired carbapenemase-producing bacteria, particularly metallo-β-lactamases (MBL). Rapid detection of MBL-producing Gram-negative bacilli is essential to prevent their widespread dissemination. However, no standardized detection method is available for routine laboratory use. The purpose of the study was to evaluate a chelating-agent based double disk synergic test and disk potentiation test for MBL-producing strain detection and to determine the isolation rate of MBL-producing Pseudomonas aeruginosa and Acinetobacter from clinical samples in our tertiary teaching hospital. A total of 22 and 66 imipenem-resistant P. aeruginosa and Acinetobacter isolates respectively were tested with ceftazidime (CAZ) disk by modified double disk synergic test and disk potentiation test using ethylenediaminetetraacetic acid (EDTA) and 2-mercaptopropionic acid (as chelating agents) to detect MBL production. The tests were compared with EDTA-phenanthroline-imipenem (EPI) microdilution MIC test as gold standard. MBL positive strains were detected in 17 (77.3%) P. aeruginosa and 2 (3.5%) Acinetobacter isolates. The disk potentiation test with 2-mercaptopropionic acid (2-MPA) dilution of 1:12 provided the most acceptable sensitivities and specificities (88.2% sensitivity and 100% specificity in P. aeruginosa; 100% sensitivity and specificity in Acinetobacter) compared to other screening methods used in this study. This study provided useful information on the local prevalence of MBL-producing P. aeruginosa and Acinetobacter in our hospital. Disc potentiation test with CAZ/2-MPA disc appears to be reliable and convenient MBL detection method in the routine clinical laboratory.
    Matched MeSH terms: Bacterial Proteins/analysis*
  20. 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 Proteins/analysis
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