فهرست مطالب
Avicenna Journal of Clinical Microbiology and Infection
Volume:3 Issue: 1, Feb 2016
- تاریخ انتشار: 1395/02/07
- تعداد عناوین: 6
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Page 1BackgroundPanton-Valentine leukocidin (luk-pv) is a cytotoxin that causes leukocyte destruction and tissue necrosis..ObjectivesThe aim of this study was to determine the prevalence of the pv1, femA, and mecA genes in staphylococcus aureus isolates from clinical specimens in hospitals in Ilam, Iran..Materials And MethodsOne hundred and sixty Staphylococcus aureus isolates were collected from hospitals in Ilam, Iran, and phenotypic and genotypic examinations for methicillin-resistant S. aureus (MRSA) isolates were carried out. The antibiotic profiles of these isolates, and the minimal inhibitory concentration (MIC) of MRSA isolates was determined using the agar dilution method with vancomycin, cefoxitin, and oxacillin. All isolates were examined using polymerase chain reaction (PCR) primers for the femA, mecA, and Panton Valentine leukocidin (luk-pv) genes..ResultsThe results showed 91 isolates (56.88%) were coagulase-positive, and 69 isolates (43.12%) were coagulase-negative Staphylococcus aureus (CNSA). Out of 91 (56.88%) coagulase-positive staphylococci, 32 isolates (35.16%) were resistant to cefoxitin, and 30 isolates (32.96%) were resistant to oxacillin, using disc diffusion method. PCR revealed the presence of the femA gene (510 bp band) in all coagulase-positive isolates (100%), and the mecA gene (513 bp band) was detected in 32 isolates (35.16%); out of 32 MRSA isolates, 13 isolates (40.62%) were positive for presence of the luk-pv gene (433 bp band)..ConclusionsThe cefoxitin disk diffusion method showed the best results when compared to oxacillin disk, similar to results from detecting the mecA gene in PCR as a golden test. Studies on MRSA that carry the luk-pv gene should continue to provide significant insight into the prevalence and epidemiology of these important resistant pathogens. Also, the rate of pvl gene-producing isolates showed to be relatively high, and it should be detected in all staphylococcal infections..Keywords: Methicillin Resistance, Staphylococcus aureus, Paton, Valentine, Ilam
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Page 2BackgroundInfections due to Acinetobacter baumannii have become a significant challenge in modern healthcare systems. The global upsurge of multidrug resistance in A. baumannii has created widespread problems in the treatment of patients..ObjectivesWe examined the prevalence ISAmpC and its correlation with cefotaxime resistance..Materials And MethodsStandard biochemical tests were used to identify isolates. Genomic species of the genus Acinetobacter were confirmed by Amplified Ribosomal DNA Restriction Analysis (ARDRA). The susceptibility of 50 A. baumannii isolates to a variety of antimicrobial agents was determined using the disk diffusion method and E-test strips. PCR was used to investigate the connection of insertion sequences and the ampC gene. Clonal relatedness was determined by Repetitive Extragenic Palindromic PCR..ResultsISAba1 located upstream of blaampC was found in 24 (48%) of the A. baumannii isolates. In all of the studied isolates that had ISAmpC, the MIC for cefotaxime was 64 - 256 μg/mL. Based on the REP-PCR patterns among the resistant isolates, the highest number of ISAmpC positive isolates belonged to type B (n = 19) and type C (n = 12)..ConclusionsISAba1 has become an important factor in A. baumanniis resistance to cefotaxime..Keywords: ISAba1, ampC, Nosocomial Infection, Acinetobacter baumannii
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Page 3BackgroundProbiotics are survival microorganisms that, when administered in sufficient amounts, confer health benefits to the host and can be used in an antioxidative role..ObjectivesThe antioxidative effect of whole cells and intracellular cell-free extracts of the lactic acid bacteria Lactobacillus acidophilus (PTCC 1643) as a probioticý at three different time intervals was investigated..Materials And MethodsAntioxidant biomarkers, such as total antioxidant power (TAP), measured with the FRAP (ferric-reducing ability of plasma) method, were evaluated at 24, 48, and 72 hours..ResultsThe results showed that extracts and bacteria of L. acidophilus were able to significantly increase TAP after 24 and 72 hours..ConclusionsThe results showed that the effect of L. acidophilus is time-dependent..Keywords: Antioxidants, Probiotics, Lactobacillus acidophilus
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Page 4BackgroundMultidrug resistance among different pathogens is increasing immensely day by day. To control these problems, we need new potent antimicrobial agents in repository of antibiotics..ObjectivesThis study aimed at investigation of antibiotics resistance pattern of pathogenic Klebsiella strains isolated from clinical samples in Lahore region Pakistan and study inhibition of resistant strains by natural extracts obtained from actinomycetes isolated from different ecological niches in Pakistan..Materials And MethodsThe isolated Klebsiella strains were identified by morphological, biochemical and physiological characterization along with 16S rRNA gene sequencing. Antibiotics susceptibility was determined by standard Kirby Bauer disc diffusion assay. The biological and chemical screening was performed for detection of active secondary metabolites produced by actinomycetes against resistant Klebsiella strains. Biological screenings include antimicrobial activity by agar diffusion assay and brine shrimp microwell cytotoxicity assay. In chemical screening, the crude extracts of actinomycetes strains were analysed by TLC and HPLC-UV techniques..ResultsThe isolated Klebsiella strains showed resistance against most of the antibiotics as follows; ceftriaxone > cephalexin > cefpirome > cefoxitin = cefepime > levofloxacin > ciprofloxacin = ceftrazidime = fusidum > cefoperazone > ampicillin sulbactam. The actinomycetes strain A19, A20, A2, A10, A6 and A8 exhibited remarkable activity against resistant Klebsiella strains. The strains A19 and 20 showed excellent inhibitory effects on all isolated multidrug resistant Klebsiella strains..ConclusionsThe clinical Klebsiella strains isolated from Lahore region, Pakistan exhibited resistance to most commonly used antibiotics, which can be a serious threat to public health. The study reported some potential actinomycetes strains, which exhibit promising activity against multidrug resistant Klebsiella strains..Keywords: Antimicrobial Agents, Actinomycetes, Cytotoxicity, HPLC, UV, Klebsiella
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Page 5BackgroundThe use of imipenem antibiotics against Gram-negative bacteria is growing, but the incidence of imipenem-resistant bacteria is also increasing..ObjectivesThe aim of this study was to determine the risk factors for imipenem resistance in patients with Gram-negative bacteria infections..
Patients andMethodsAn imipenem minimum inhibitory concentrations (MIC) test was done using the E-test, and a survey of different risk factors of imipenem resistance in 374 patients who were infected solely by Gram-negative bacteria was performed..ResultsOf the 374 isolated, 134 were imipenem resistant, and 240 were sensitive to imipenem. The resistance rate was more common in males and in patients with intensive care unit (ICU) admission, trauma-induced infections, a history of antibiotic use, the need for ventilator support, or central venous catheter insertion, and in nosocomial infections..ConclusionsOur results showed the rate of effects of different risk factors on imipenem resistance. Regarding the studied risk factors, appropriate programs must be set in place to control and prevent imipenem resistance in Gram-negative bacteria..Keywords: Risk Factors, Imipenem, Gram, Negative Bacteria, Drug Resistance