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Showing 4 results for Boustanshenas
Volume 2, Issue 1 (1-2016)
Abstract
Background: Aeromonas spp. can cause diarrhea and various infections in humans. Access to rapid techniques with a high sensitivity and specificity is strongly needed for the identification of Aeromonas species. The aim of this study was to evaluate two different methods including API 20E bacterial identification tests and the molecular detection using PCR primers specific for 16s-rRNA and 23S-rRNA genes sequences for identification of Aeromonas spp. in stool samples from patients with diarrhea. Materials and Methods: One hundred stool samples from diarrheal patients were collected. All isolates were subjected toAPI 20 E strip tests and PCR using specific primers for identification of Aeromonas spp. Results: The API 20E analysis identified 2 (2.2%) isolates as Aeromonas spp. Molecular identification by aero-23S-rRNA gene confirmed the same 2 isolates as identified by the API 20E strips. Conclusion: Both API 20E system and PCR method using Aero 23S-rRNA primer were found to be accurate in identification of Aeromonas spp. isolates with highconfidence.
Volume 2, Issue 2 (4-2016)
Abstract
Vibrio cholerae O1 are classified into two biotypes, classical and El Tor based on susceptibility to bacteriophages and some biochemical properties, each encoding a biotype-specific genetic determinants. Before 1961, most epidemics had been caused by the classical biotype. However, with the passage of time, the classical biotype missed from the scenario and the El Tor emerged as the major biotype causing the cholera in humans. The present cholera global pandemic is attributed to a change among seventh pandemic strains and emergence of V. cholerae O139, V. cholerae O1 El Tor hybrid, and V. cholera O1 El Tor with altered cholera toxin subunit B. The V. cholerae biotypes are not only different in phenotype but also human infections caused by them are different clinically. Infection with classical V. cholerae O1 more frequently produces severe infection than does El Tor, suggesting that the genetic and phenotypic differences between the two biotypes may also be reflected in their pathogenic potential. Considering the recent emergence of “hybrid biotype” and “El Tor variant” in different areas and in our country, we reviewed differences in genetic structure of V. cholerae biotypes.
Volume 4, Issue 3 (Summer 2018)
Abstract
Aims: Colistin resistant Acinetobacter baumannii strains have become an important treat in nosocomial infection control. The reliable detection of these strains plays a critical role in treatment procures. The aim of this study was to evaluate the three different methods in detection of colistin resistant A. baumannii strains.
Materials & Methods: Eighty-three A. baumannii strains were isolated from hospitalized patients of a teaching hospital in Tehran during 1 year (2016-2017). All isolates were genetically confirmed by Polymerase Chain Reaction (PCR). The resistance to colistin was determined with disc diffusion, E-test, and micro broth dilution method.
Findings: According to the results of micro broth dilution as a gold standard, 43% of the isolates were resistant to colistin, while this percentage was 23% and 44% through E-test and disc diffusion methods, respectively. The positive and negative predictive value (PPV and NPV) of this method was 43% and 57%, respectively. The sensitivity and NPV index of E-test for the detection of colistin resistant strains was 76% and 68%.
Conclusion: Detection of colistin MIC by E-test strips has been commonly used in clinical laboratories to recognize the colistin susceptible strains. The NPV and sensitivity of E-test method demonstrated that this method has inefficacy to accurate determination of colistin susceptible strains. Thus, using standard protocol micro broth dilution with qualified materials should be stabilized and replaced instead of disc diffusion or even using E-test in clinical laboratories.
Volume 6, Issue 1 (Winter 2020)
Abstract
Background: This study aimed to evaluate the prevalence of tet genes and Class I and 2 integrons in Enterobacter cloacae strains isolated from patients with urinary tract infections (UTIs).
Materials & Method: A total of 50 E. cloacae isolates were collected. Antimicrobial susceptibility pattern and tetracycline MIC were determined. The presence of tet genes (tetA, tetB, tetC, tetD) and Class 1 and 2 integrons and the content of Class 1 integron were determined.
Findings: Tetracycline MIC pattern classified 36 % of the E. cloacae isolates as resistant. The most common tet gene was tetC (22%), followed by tetD, tetA, and tetB. Class 1 integron was detected in 64% of the isolates. Class 1 integron content analysis showed two variable gene cassettes (aadA1 and aadA5/dfrA17 genes). The frequency of aadA5/dfrA17 was 18.75%, which was more common than aadA1 gene (6.25%).
Conclusion: The most important genetic markers for tetracycline resistance in E. cloacae isolates were tetC and Class 1 integron. Harboring Class 1 integron and resistance to streptomycin and ciprofloxacin were significantly correlated.
