Displaying publications 141 - 160 of 892 in total

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  1. Vamsi K, Siddiqui F
    J Contemp Dent Pract, 2018 Jul 01;19(7):824-829.
    PMID: 30066686
    AIM: To study the antimicrobial effect of chlorhexidine diacetate (CHX-D)-modified type II glass ionomer cement (GIC) against the two predominant deep caries microorganisms, namely Lactobacillus casei and Actinomyces viscosus.

    MATERIALS AND METHODS: An experimental GIC (ex-GIC) was prepared by mixing CHX-D powder with the powder of type II GIC to obtain 1% (w/w) concentration of CHX-D in the GIC. Antibacterial activity of this ex-GIC was tested against L. casei and A. viscosus using the agar diffusion method. The ex-GIC specimens were tested in their unset and set forms for each bacterium. For the unset group, specimens were placed in each agar plate immediately after manipulation and for the set group, specimens were placed in each agar plate, 1 hour after manipulation. The inhibition zones on the agar plate were recorded in millimeters immediately on placement of the specimen in the agar plate and after 48 hours. The reading was recorded and statistically analyzed for significant difference.

    RESULTS: Mann-Whitney U test showed statistically significant difference in the inhibition zones produced by ex-GIC against L. casei and A. viscosus when both were compared in unset (p-value = 0.002) and set (p-value = 0.031) groups. For both the groups, the zone of inhibition against L. casei was greater. Though the unset group recorded wider zone of inhibition, the difference was not significant when compared with the respective set group. This was true for both the bacterial groups.

    CONCLUSION: The 1% CHX-D-modified type II GIC showed antibacterial property against L. casei and A. viscosus and significantly higher activity against L. casei.

    CLINICAL SIGNIFICANCE: Addition of 1% CHX-D to type II GIC showed evidence of antibacterial activity against organisms found in deep carious lesion and therefore may exhibit superior antimicrobial efficiency when used as an intermediate therapeutic restoration in deep cavities.

    Matched MeSH terms: Microbial Sensitivity Tests/methods
  2. Rehman A, Siddiqa A, Abbasi MA, Siddiqui SZ, Khan SG, Rasool S, et al.
    Pak J Pharm Sci, 2018 Sep;31(5):1783-1790.
    PMID: 30150171
    A number of novel 5-substituted-2-((6-bromo-3,4-methylenedioxybenzyl)thio)-1,3,4-Oxadiazole derivatives (6a-l) have been synthesized to evaluate their antibacterial activity. Using aryl/aralkyl carboxylic acids (1a-l) as precursors, 5-substituted-1,3,4-Oxadiazol-2-thiols (4a-l) were yielded in good amounts. The derivatives, 4a-l, were subjected to electrophilic substitution reaction on stirring with 6-bromo-3,4-methylenedioxybenzyl chloride (5) in DMF to synthesize the required compounds. All the synthesized molecules were well characterized by IR, 1H-NMR, 13C-NMR and EIMS spectral data and evaluated for antibacterial activity against some bacterial strains of Gram-bacteria. The molecule, 6d, demonstrated the best activity among all the synthesized molecules exhibiting weak to moderate inhibition potential.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  3. Yap JKY, Tan SYY, Tang SQ, Thien VK, Chan EWL
    Microb Drug Resist, 2021 Feb;27(2):234-240.
    PMID: 32589487 DOI: 10.1089/mdr.2020.0178
    Aims: Currently, limited antibiotics are available to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. One approach is the use of adjuvants in antibiotic therapy. 1,4-Naphthoquinones are naturally occurring alkaloids shown to have antibacterial properties. The objective of this study is to investigate the synergy between 1,4-naphthoquinone and selected β-lactam antibiotics and to evaluate the potential use of 1,4-naphthoquinone as an adjuvant in antibiotic treatment against MRSA infections. Methods: The antibacterial activity of 1,4-naphthoquinone and plumbagin was tested against nine pathogenic bacterial strains using the microdilution broth method. The interactions between 1,4-naphthoquinone and three antibiotics (cefuroxime, cefotaxime, and imipenem) were estimated by calculating the fractional inhibitory concentration of the combination. Results: The compounds 1,4-naphthoquinone and plumbagin exhibited a broad range of bacteriostatic and bactericidal effects against both Gram-positive and Gram-negative bacteria. The interaction between 1,4-naphthoquinone and imipenem, cefuroxime, and cefotaxime was synergistic against methicillin-sensitive Staphylococcus aureus and MRSA clinical strains. Against ATCC-cultured MRSA, a synergistic effect was observed between 1,4-naphthoquinone and cefotaxime. However, combination with imipenem only produced an additive effect, and an antagonistic action was observed between 1,4-naphthoquinone and cefuroxime. Conclusions: Although individually less potent than common antibiotics, 1,4-naphthoquinone acts synergistically with imipenem, cefuroxime, and cefotaxime against MRSA clinical strains and could potentially be used in adjuvant-antibiotic therapy against multidrug resistant bacteria.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  4. Salhi N, Mohammed Saghir SA, Terzi V, Brahmi I, Ghedairi N, Bissati S
    Biomed Res Int, 2017;2017:7526291.
    PMID: 29226147 DOI: 10.1155/2017/7526291
    Aim: This study investigated the antifungal properties of aqueous extracts obtained from indigenous plants that grow spontaneously in the Northern Sahara of Algeria. The activities of these plants in controlling two fungal species that belong to Fusarium genus were evaluated in an in vitro assay.

    Materials and Methods: Fresh aerial parts of four plant species (Artemisia herba alba, Cotula cinerea, Asphodelus tenuifolius, and Euphorbia guyoniana) were collected for the preparation of aqueous extracts. Two levels of dilution (10% and 20%) of the pure extracts were evaluated against Fusarium graminearum and Fusarium sporotrichioides.

    Results: The results of this study revealed that the A. herba alba, C. cinerea, A. tenuifolius, and E. guyoniana aqueous extracts are effective at both concentrations of 10% and 20% for the Fusarium mycelia growth inhibition. In particular, A. tenuifolius extract is effective against F. graminearum, whereas F. sporotrichioides mycelium growth is strongly affected by the E. guyoniana 20% extract. The phytochemical characterization of the compositions of the aqueous extracts has revealed that the presence of some chemical compounds (tannins, flavonoids, saponins, steroids, and alkaloids) is likely to be responsible for the antifungal activities sought.

    Conclusion: The antifungal properties of A. herba alba, C. cinerea, A. tenuifolius, and E. guyoniana make these plants of potential interest for the control of fungi affecting both wheat yield and safety.

    Matched MeSH terms: Microbial Sensitivity Tests/methods
  5. Khalid KA, Zakaria Z, Toung OP, McOrist S
    Vet Rec, 2009 May 16;164(20):626-7.
    PMID: 19448256
    Matched MeSH terms: Microbial Sensitivity Tests/veterinary
  6. Mohd Yusof H, Abdul Rahman N, Mohamad R, Zaidan UH, Samsudin AA
    Sci Rep, 2020 Nov 17;10(1):19996.
    PMID: 33204003 DOI: 10.1038/s41598-020-76402-w
    This study aims to utilize the cell-biomass (CB) and supernatant (CFS) of zinc-tolerant Lactobacillus plantarum TA4 as a prospective nanofactory to synthesize ZnO NPs. The surface plasmon resonance for the biosynthesized ZnO NPs-CFS and ZnO NPs-CB was 349 nm and 351 nm, respectively, thereby confirming the formation of ZnO NPs. The FTIR analysis revealed the presence of proteins, carboxyl, and hydroxyl groups on the surfaces of both the biosynthesized ZnO NPs that act as reducing and stabilizing agents. The DLS analysis revealed that the poly-dispersity indexes was less than 0.4 for both ZnO NPs. In addition, the HR-TEM micrographs of the biosynthesized ZnO NPs revealed a flower-like pattern for ZnO NPs-CFS and an irregular shape for ZnO NPs-CB with particles size of 291.1 and 191.8 nm, respectively. In this study, the biosynthesized ZnO NPs exhibited antibacterial activity against pathogenic bacteria in a concentration-dependent manner and showed biocompatibility with the Vero cell line at specific concentrations. Overall, CFS and CB of L. plantarum TA4 can potentially be used as a nanofactory for the biological synthesis of ZnO NPs.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  7. Javaid A, Ahmad N, Afridi AK, Basit A, Khan AH, Ahmad I, et al.
    Am J Trop Med Hyg, 2018 06;98(6):1629-1636.
    PMID: 29611497 DOI: 10.4269/ajtmh.17-0936
    To evaluate the predictive value of time to sputum culture conversion (SCC) in predicting cure and factors associated with time to SCC and cure in multidrug-resistant tuberculosis (MDR-TB) patients, a retrospective study was conducted at programmatic management unit of drug resistant tuberculosis (TB), Peshawar. A total of 428 pulmonary MDR-TB patients enrolled at the study site from January 1, 2012 to August 31, 2014 were followed until treatment outcome was recorded. Survival analysis using Cox proportional hazards model and multivariate binary logistic regression were, respectively, used to identify factors associated with time to SCC and cure. A P value < 0.05 was considered statistically significant. Overall, 90.9% patients achieved SCC, and 76.9% were cured. Previous use of second-line drugs (SLDs) (hazard ratio [HR] = 0.637; 95% confidence interval [CI] = 0.429-0.947), ofloxacin resistance (HR = 0.656; 95% CI = 0.522-0.825) and lung cavitation (HR = 0.744; 95% CI = 0.595-0.931) were significantly associated with time to SCC. In predicting cure, sensitivities of SCC at 2, 4, and 6 months were 64.1% (95% CI = 58.69-69.32), 93.0% (95% CI = 89.69-95.52), and 97.6% (95% CI = 95.27-98.94), respectively, whereas specificities were 67.7% (95% CI = 57.53-76.73), 51.5% (95% CI = 41.25-61.68), and 44.4% (95% CI = 34.45-54.78), respectively. Furthermore, patients' age of 41-60 (odds ratio [OR] = 0.202; 95% CI = 0.067-0.605) and > 60 years (OR = 0.051; 95% CI = 0.011-0.224), body weight > 40 kg (OR = 2.950; 95% CI = 1.462-5.952), previous SLD use (OR = 0.277; 95% CI = 0.097-0.789), lung cavitation (OR = 0.196; 95% CI = 0.103-0.371) and ofloxacin resistance (OR = 0.386; 95% CI = 0.198-0.749) were significantly associated with cure. Association of SCC with cure was substantially stronger at 6 months (OR = 32.10; 95% CI = 14.34-71.85) than at 4 months (OR = 14.13; 95% CI = 7.92-25.21). However in predicting treatment outcomes, the combined sensitivity and specificity of SCC at 4 months was comparable to SCC at 6 months. Patients with risk factors for delayed SCC were also at high risk of unsuccessful outcomes.
    Matched MeSH terms: Microbial Sensitivity Tests/methods; Microbial Sensitivity Tests/standards
  8. Ahmad R, Baharum SN, Bunawan H, Lee M, Mohd Noor N, Rohani ER, et al.
    Molecules, 2014 Nov 20;19(11):19220-42.
    PMID: 25420073 DOI: 10.3390/molecules191119220
    The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots) of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME) and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol) extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane) showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  9. Jamali H, Paydar M, Radmehr B, Ismail S
    J Dairy Sci, 2015 Feb;98(2):798-803.
    PMID: 25497824 DOI: 10.3168/jds.2014-8853
    The aims of this study were to investigate the prevalence and to characterize and determine the antibiotic resistance of Yersinia spp. isolates from raw milk. From September 2008 to August 2010, 446 raw milk samples were obtained from farm bulk milk tanks in Varamin, Iran. Yersinia spp. were detected in 29 (6.5%) samples, out of which 23 (79.3%), 5 (17.2%), and 1 (3.4%) were isolated from cow, sheep, and goat raw milk, respectively. The most common species isolated was Yersinia enterocolitica (65.5%), followed by Yersinia frederiksenii (31%), and Yersinia kristensenii (3.4%). Of the 19 Y. enterocolitica isolates, 14 (73.7%) were grouped into bioserotype 1A/O:9, 4 (21.1%) belonged to bioserotype 1B:O8, 1 (5.3%) belonged to bioserotype 4/O:3, and 1 isolate (biotype 1A) was not typable. All the isolates of biotypes 1B and 4harbored both the ystA and ail genes. However, all the isolates of biotype 1A were only positive for the ystB gene. The tested Yersinia spp. showed the highest percentages of resistance to tetracycline (48.3%), followed by ciprofloxacin and cephalothin (each 17.2%), ampicillin (13.8%), streptomycin (6.9%), and amoxicillin and nalidixic acid (each 3.4%). All of the tested isolates demonstrated significant sensitivity to gentamicin and chloramphenicol. Recovery of potentially pathogenic Y. enterocolitica from raw milk indicates high risks of yersiniosis associated with consumption of raw milk.
    Matched MeSH terms: Microbial Sensitivity Tests/veterinary
  10. Hamzan NI, Yean CY, Rahman RA, Hasan H, Rahman ZA
    Emerg Health Threats J, 2015;8:26011.
    PMID: 25765342 DOI: 10.3402/ehtj.v8.26011
    Background : Antibiotic resistance among Enterobacteriaceae posts a great challenge to the health care service. The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) is attracting significant attention due to its rapid and global dissemination. The infection is associated with significant morbidity and mortality, thus creating challenges for infection control and managing teams to curb the infection. In Southeast Asia, there have been limited reports and subsequent research regarding CRKP infections. Thus, the study was conducted to characterize CRKP that has been isolated in our setting. Methods : A total of 321 K. pneumoniae were included in the study. Each isolate went through an identification process using an automated identification system. Phenotypic characterization was determined using disk diffusion, modified Hodge test, Epsilometer test, and inhibitor combined disk test. Further detection of carbapenemase genes was carried out using polymerase chain reaction and confirmed by gene sequence analysis. Results : All together, 13 isolates (4.05%) were CRKP and the majority of them were resistant to tested antibiotics except colistin and tigercycline. Among seven different carbapenemase genes studied (blaKPC, bla IMP, bla SME, bla NDM, bla IMI, bla VIM, and bla OXA), only two, bla IMP4 (1.87%) and bla NDM1 (2.18%), were detected in our setting. Conclusion : Evidence suggests that the prevalence of CRKP in our setting is low, and knowledge of Carbapenem-resistant Enterobacteriaceae and CRKP has improved and become available among clinicians.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  11. Aween MM, Hassan Z, Muhialdin BJ, Eljamel YA, Al-Mabrok AS, Lani MN
    J Food Sci, 2012 Jul;77(7):M364-71.
    PMID: 22757710 DOI: 10.1111/j.1750-3841.2012.02776.x
    A total of 32 lactic acid bacteria (LAB) were isolated from 13 honey samples commercially marketed in Malaysia, 6 strains identified as Lactobacillus acidophilus by API CHL50. The isolates had antibacterial activities against multiple antibiotic resistant's Staphylococcus aureus (25 to 32 mm), Staphylococcus epidermis (14 to 22 mm) and Bacillus subtilis (12 to 19 mm) in the agar overlay method after 24 h incubation at 30 °C. The crude supernatant was heat stable at 90 °C and 121 °C for 1 h. Treatment with proteinase K and RNase II maintained the antimicrobial activity of all the supernatants except sample H006-A and H010-G. All the supernatants showed antimicrobial activities against target bacteria at pH 3 and pH 5 but not at pH 6 within 72 h incubation at 30 °C. S. aureus was not inhibited by sample H006-A isolated from Libyan honey and sample H008-D isolated from Malaysian honey at pH 5, compared to supernatants from other L. acidophilus isolates. The presence of different strains of L. acidophilus in honey obtained from different sources may contribute to the differences in the antimicrobial properties of honey.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  12. Lim KT, Yasin RM, Yeo CC, Puthucheary SD, Balan G, Maning N, et al.
    J Microbiol Immunol Infect, 2009 Jun;42(3):197-209.
    PMID: 19812853
    Pseudomonas aeruginosa is the third most common pathogen causing nosocomial infections. The objective of this study was to investigate the antimicrobial resistance profiles and genetic diversity of hospital isolates of P. aeruginosa and to investigate the presence of several resistance genes and integrons.
    Matched MeSH terms: Microbial Sensitivity Tests*
  13. Modarresi-Chahardehi A, Ibrahim D, Fariza-Sulaiman S, Mousavi L
    Rev. Biol. Trop., 2012 Dec;60(4):1567-76.
    PMID: 23342511
    Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30 microg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to antimicrobial activity extracts from extraction method I (33 out of 152 of crude extracts) and 6.82% from extraction method II (13 out of 190 of crude extracts). However, crude extracts from method I exhibited better antimicrobial activity against the Gram-positive bacteria than the Gram-negative bacteria. The positive results on medicinal plants screening for antibacterial activity constitutes primary information for further phytochemical and pharmacological studies. Therefore, the extracts could be suitable as antimicrobial agents in pharmaceutical and food industry.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  14. Tay ST, Chai HC, Na SL, Hamimah H, Rohani MY, Soo-Hoo TS
    Mycopathologia, 2005 Jun;159(4):509-13.
    PMID: 15983736
    The occurrence of Cryptococcus neoformans in bird excreta in Klang valley, Malaysia was determined in this study. Of 544 samples of bird excreta collected from a local zoo, pet shops and public areas, 20 strains of C. neoformans were isolated. All C. neoformans strains were serotype A and thus identified as C. neoformans variety grubii. All did not produce color changes on canavanine-glycine-bromothymol blue agar. All were of alpha-mating types, as determined by a pheromone-specific PCR assay. The antifungal susceptibility testing using agar diffusion method Neo-sensitabs showed that all were susceptible to amphotericin B, fluconazole and itraconazole.
    Matched MeSH terms: Microbial Sensitivity Tests/veterinary
  15. Ghanem OB, Mutalib MI, El-Harbawi M, Gonfa G, Kait CF, Alitheen NB, et al.
    J Hazard Mater, 2015 Oct 30;297:198-206.
    PMID: 25965417 DOI: 10.1016/j.jhazmat.2015.04.082
    Tuning the characteristics of solvents to fit industrial requirements has currently become a major interest in both academic and industrial communities, notably in the field of room temperature ionic liquids (RTILs), which are considered one of the most promising green alternatives to molecular organic solvents. In this work, several sets of imidazolium-based ionic liquids were synthesized, and their toxicities were assessed towards four human pathogens bacteria to investigate how tunability can affect this characteristic. Additionally, the toxicity of particular RTILs bearing an amino acid anion was introduced in this work. EC50 values (50% effective concentration) were established, and significant variations were observed; although all studied ILs displayed an imidazolium moiety, the toxicity values were found to vary between 0.05 mM for the most toxic to 85.57 mM for the least toxic. Linear quantitative structure activity relationship models were then developed using the charge density distribution (σ-profiles) as molecular descriptors, which can yield accuracies as high as 95%.
    Matched MeSH terms: Microbial Sensitivity Tests*
  16. Mohammed AAM, Suaifan GARY, Shehadeh MB, Okechukwu PN
    Drug Dev Res, 2019 02;80(1):179-186.
    PMID: 30570767 DOI: 10.1002/ddr.21508
    In the quest for discovering potent antimicrobial agents with lower toxicity, we envisioned the design and synthesis of nalidixic acid-D-(+)-glucosamine conjugates. The novel compounds were synthesized and evaluated for their in vitro antimicrobial activity against Gram positive bacteria, Gram negative bacteria and fungi. Cytotoxicity using MTT assay over L6 skeletal myoblast cell line, ATCC CRL-1458 was carried out. In vitro antimicrobial assay revealed that 1-ethyl-7-methyl-4-oxo-N-(1,3,4,6-tetra-O-acetyl-2-deoxy-D-glucopyranose-2-yl)-[1,8]-naphthyridine-3-carboxamide (5) and 1-ethyl-7-methyl-4-oxo-N-(2-deoxy-D-glucopyranose-2-yl)-[1,8]-naphthyridine-3-carboxamide(6) possess growth inhibitory activity against resistant Escherichia coli NCTC, 11954 (MIC 0.1589 mM) and Methicillin resistant Staphylococcus aureus ATCC, 33591 (MIC 0.1589 mM). Compound (5) was more active against Listeria monocytogenes ATCC 19115 (MIC 0.1113 mM) in comparison with the reference nalidixic acid (MIC 1.0765 mM). Interestingly, compound (6) had potential antifungal activity against Candida albicans ATCC 10231 (MIC <0.0099 mM). Remarkably, the tested compounds had low cytotoxic effect. This study indicated that glucosamine moiety inclusion into the chemical structure of the marketed nalidixic acid enhances antimicrobial activity and safety.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  17. Jamaludin N, Gedye K, Collins-Emerson J, Benschop J, Nulsen M
    Microb Drug Resist, 2019 Sep;25(7):1003-1011.
    PMID: 31021281 DOI: 10.1089/mdr.2018.0111
    Aim:
    To characterize mutations in penA, mtrR, ponA, and porBIB, considered target genes for antimicrobial resistance, in Neisseria gonorrhoeae isolates with elevated minimum inhibitory concentrations (MICs) of ceftriaxone cultured from patients in New Zealand.
    Results:
    Out of 28 isolates supplied by the Institute of Environmental Science and Research Limited (ESR), Porirua, New Zealand, 14 were found to show reduced susceptibility to ceftriaxone (MIC of 0.06 mg/L) according to criteria used by the ESR and the Australian Gonococcal Surveillance Programme (AGSP) when tested in our laboratory. Rates of resistance to ciprofloxacin, azithromycin, penicillin, and tetracycline were 100% (28/28), 7% (2/28), 36% (10/28), and 25% (7/28), respectively. Ten different penA (Penicillin binding protein 2 [PBP2]) sequences were observed. The most common mosaic penA M-1 resembled mosaic penA XXXIV, which has been associated with ceftriaxone treatment failures in other countries. Four semimosaic PBP2 sequences were observed and may be novel PBP sequences, while four out of five nonmosaic PBP2 sequences were similar to PBP2 sequences reported in Australia. Twenty-one isolates harbored mutations in all 4 genes (penA, mtrR, porBIB, and ponA), and 13 of these exhibited reduced susceptibility to ceftriaxone.
    Conclusion:
    Mutations in penA, mtrR, porBIB, and ponA observed in this study may have contributed to reduced susceptibility to ceftriaxone among New Zealand gonococcal isolates. Over half (16/22) of mosaic penA sequences from the gonococcal isolates resembled penA XXXIV.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  18. Liew FY, Tay ST, Puthucheary SD
    Trop Biomed, 2011 Dec;28(3):646-50.
    PMID: 22433895 MyJurnal
    Ciprofloxacin, a quinolone with good intracellular penetration may possibly be used for treatment of melioidosis caused by Burkholderia pseudomallei, but problems with resistance may be encountered. Amino acid substitutions in gyrA/gyrB have given rise to fluoroquinolone resistance in various microorganisms. Using published primers for gyrA and gyrB, PCR was performed on 11 isolates of B. pseudomallei with varying degrees of sensitivity to ciprofloxacin, followed by DNA sequencing to detect possible mutations. Results showed an absence of any point mutation in either gene. Local isolates have yet to develop full resistance to ciprofloxacin and probably other mechanisms of resistance may have been involved in the decreased sensitivity to ciprofloxacin.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
  19. Ding CH, Ismail Z, Sulong A, Wahab AA, Gan B, Mustakim S, et al.
    Malays J Pathol, 2020 Dec;42(3):401-407.
    PMID: 33361721
    INTRODUCTION: Rifampicin is a key first-line antimycobacterial agent employed for the treatment of pulmonary tuberculosis (PTB). This study sought to obtain prevalence data on rifampicin-resistant Mycobacterium tuberculosis among smear-positive PTB patients in the Klang District of Malaysia.

    MATERIALS AND METHODS: A total of 103 patients from the Chest Clinic of Hospital Tengku Ampuan Rahimah with sputum smears positive for acid-fast bacilli were included in this cross-sectional study. All sputa were tested using Xpert MTB/RIF to confirm the presence of M. tuberculosis complex and detect rifampicin resistance. Sputa were also sent to a respiratory medicine institute for mycobacterial culture. Positive cultures were then submitted to a reference laboratory, where isolates identified as M. tuberculosis complex underwent drug susceptibility testing (DST).

    RESULTS: A total of 58 (56.3%) patients were newly diagnosed and 45 (43.7%) patients were previously treated. Xpert MTB/RIF was able to detect rifampicin resistance with a sensitivity and specificity of 87.5% and 98.9%, respectively. Assuming that a single resistant result from Xpert MTB/RIF or any DST method was sufficient to denote resistance, a total of 8/103 patients had rifampicinresistant M. tuberculosis. All eight patients were previously treated for PTB (p<0.05). The overall prevalence of rifampicin resistance among smear-positive PTB patients was 7.8%, although it was 17.8% among the previously treated ones.

    CONCLUSION: The local prevalence of rifampicin-resistant M. tuberculosis was particularly high among previously treated patients. Xpert MTB/RIF can be employed in urban district health facilities not only to diagnose PTB in smear-positive patients, but also to detect rifampicin resistance with good sensitivity and specificity.

    Matched MeSH terms: Microbial Sensitivity Tests/methods*
  20. Mobasseri G, Teh CSJ, Ooi PT, Tan SC, Thong KL
    Microb Drug Resist, 2019 Sep;25(7):1087-1098.
    PMID: 30844323 DOI: 10.1089/mdr.2018.0184
    Aims:
    The high prevalence of multidrug resistance (MDR) and extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae associated with nosocomial infections has caused serious therapeutic challenges. The objectives of this study were to determine the genotypic and phenotypic characteristics of K. pneumoniae strains isolated from Malaysian swine farms and the transferability of ESBL genes by plasmids.
    Results:
    A total of 50 K. pneumoniae strains were isolated from 389 samples, which were collected from healthy and unhealthy pigs (swine rectum and oral cavities), healthy farmers (human rectum, urine, and nasal cavities), farm's environment, and animal feeds from seven Malaysian swine farms. Antimicrobial susceptibility analysis of these 50 K. pneumoniae strains showed that the majority (86%) were resistant to tetracycline, while 44% and 36% of these strains were MDR and ESBL producers, respectively. PCR and DNA sequencing of the amplicons showed the occurrence of blaTEM (15/18), blaSHV (15/18), blaCTX-M-1 group (7/18), and blaCTX-M-2 group (2/18), while only class 1 integron-encoded integrase was detected. Conjugation experiments and plasmid analysis indicated that the majority of the ESBL genes were plasmid encoded and the plasmids in 11 strains were conjugative. Genotyping by pulsed-field gel electrophoresis and repetitive extragenic palindrome-polymerase chain reaction (REP-PCR) showed that these 50 strains were genetically diverse with 44 pulsotypes and 43 REP-PCR subtypes.
    Conclusions:
    ESBL-producing K. pneumoniae strains showed high resistance to tetracycline as this antibiotic is used for prophylaxis and therapeutic purposes at the swine farms. The findings in this study have drawn attention to the issue of increasing MDR in animal husbandry and it should be taken seriously to prevent the spread and treatment failure due to antimicrobial resistance.
    Matched MeSH terms: Microbial Sensitivity Tests/methods
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