Microbiology
zahra Mottaghiyan; Davoud Esmaeili; Mohammad Hossein Ahmadi; Mohammad Niakan
Abstract
Background & Objective: Acinetobacter baumannii strains harboring Meallobetalactamases (MBL) pose a significant threat in the context of nosocomial infections. The present investigation was undertaken with the objective of devising a Multiplex PCR methodology for the concurrent detection of MBL genes ...
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Background & Objective: Acinetobacter baumannii strains harboring Meallobetalactamases (MBL) pose a significant threat in the context of nosocomial infections. The present investigation was undertaken with the objective of devising a Multiplex PCR methodology for the concurrent detection of MBL genes within A. baumannii strains prevalent in Tehran City, Iran.Methods: Between October 2020 and February 2021, 100 strains of A. baumannii were procured from burn specimens of hospitalized patients at Motahhari Hospital in Tehran. The identification of A. baumannii strains involved conventional biochemical techniques, coupled with confirmation of the presence of the bla OXA-51 gene. Antibiotic susceptibility was assessed using the Kirby–Bauer disc diffusion test. MBL-producing strains were characterized through a phenotypic approach employing the combined disk test, alongside Multiplex PCR for the simultaneous identification of bla VIM, bla IMP, bla GIM, and bla NDM genes. Statistical analyses were conducted using the chi-square test, with SPSS version 20.0 employed for data processing.Results: Among 100 strains examined, 96.1% exhibited positivity for MBL, as determined by the combined disk test. The study revealed a predominance of extensively drug-resistant (XDR) strains, with colistin demonstrating the highest level of sensitivity. The genotypic assay unveiled that Multiplex PCR identified bla VIM, bla NDM, and bla IMP in 20 strains, bla VIM and bla NDM in 30 strains, and exclusively the bla NDM gene in 45 strains. Notably, the Multiplex PCR technique exhibited the capacity to concurrently detect MBL genes (bla VIM, bla IMP, bla GIM, bla NDM) in 2 strains.Conclusion: The current investigation underscores prevalence of the bla NDM gene within clinical strains of A. baumannii. Furthermore, Multiplex PCR emerges as a robust and highly sensitive technique for rapid discernment of the MBL genes within in A. baumannii strains.
Microbiology
Farzad Mohammadi Ebli; Zoheir Heshmatipour; Khadijeh Daneshjou; Seyed Davood Siadat
Abstract
Background & Objective: Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes are among the most important causes of infection in human. Inventing rapid methods to identify these species can help in providing appropriate and effective treatment options. Therefore, the current ...
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Background & Objective: Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes are among the most important causes of infection in human. Inventing rapid methods to identify these species can help in providing appropriate and effective treatment options. Therefore, the current study aimed to develop a multiplex touch-down PCR method to identify rapidly the aforementioned species patients' sputum samples, simultaneously.Methods: A total of 50 sputum samples of patients with respiratory infections resistant to treatment were collected. After DNA extraction and primer design, the complete capsule (CAP) region II, capsular polysaccharide biosynthesis (cpsA) and the structural regulator of transcription (spy) genes were amplified for detecting H. influenzae, S. pneumoniae and S. pyogenes by multiplex touch-down PCR.Results: Among 50 samples prepared from patients with different diseases, 27 samples were positive for amplified genes. The frequency of presence of pathogens in the collected samples included 14% H. influenzae, 20% S. pneumoniae and 20% S. pyogenes. Also, in some patients, the simultaneous presence of two or three pathogens were observed.Conclusion: In general, it can be concluded that the PCR touchdown method developed in the present study is an effective and fast method for the simultaneous identification of H. influenzae, S. pneumoniae and S. pyogenes pathogens in clinical samples of patients.
Amir Tajbakhsh; Faezeh Ghasemi; Seyedeh Zohre Mirbagheri; Mastoureh Momen Heravi; Mehdi Rezaee; Zahra Meshkat
Volume 13, Issue 4 , October 2018, , Pages 429-437
Abstract
Background and Objectives: The incidence of rifampin-resistant strains of Mycobacterium tuberculosis has attracted more attention than the tuberculosis infection due to laborious treatment and control. Recognizing the Mycobacterium tuberculosis genotypes involving in drug resistance via multiplex PCR, ...
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Background and Objectives: The incidence of rifampin-resistant strains of Mycobacterium tuberculosis has attracted more attention than the tuberculosis infection due to laborious treatment and control. Recognizing the Mycobacterium tuberculosis genotypes involving in drug resistance via multiplex PCR, a simple and rapid genotyping method, is an emergency for better treatment and control of tuberculosis. This study was designed to specify the frequency of rifampin-resistant strains of Mycobacterium tuberculosis isolated from patients by multiplex allele-specific Polymerase Chain Reaction assay (MAS-PCR).Methods: In this study, 88 Mycobacterium tuberculosis positive samples were included from Qaem Hospital, Mashhad. MAS-PCR was used to detect the rifampin resistance associated mutations in rpoB gene. Results: Mutations in three codons of rpoB gene causing rifampin resistance were detected in 51 isolates (58.96%). The detected mutations in codons 531, 526, and 516 were 55.68%, 38.63%, and 13.63%, respectively. The simultaneous mutations were detected in 11 isolates (12.50%) in codons 531, 526 and 516, in 21 isolates (23.86%) in codons 531 and 526, and in one isolate (1.13%) in codons 526 and 516. Conclusion: According to the results of this study, the frequency of rifampin-resistant strains of Mycobacterium tuberculosis isolated from Khorasan province patients (North-East of Iran) was high. The developed MAS-PCR assay can be used for rapid detection in clinical diagnostic laboratories in areas with high prevalence of multidrug-resistant Mycobacterium tuberculosis strains. In this respect, MAS-PCR is simple, rapid, and highly sensitive method for drug susceptibility tests for detecting multidrug-resistant Mycobacterium tuberculosis.