Showing 4 results for Mohammadi barzelighi
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 3, Issue 2 (5-2017)
Abstract
Background: Accessory colonization factor is located immediately adjacent to and downstream of TCP cluster. These genes (acfA, B, C, D) are involved in bacterial colonization and pathogenesis. The aim of this study was to analyze the ACF cluster prevalence rate and gene content in clinical isolates of Vibrio cholerae.
Materials and Methods: All of the 21 V. cholerae isolates used in this study were collected during 2011-2012 outbreaks in Iran. All of the isolates were screened by biochemical tests and confirmed by specific PCR for 16srRNA-23srRNA intergenic space. The gene content of ACF cluster in the isolates was analyzed using 4 primer pairs with overlapping sequences and then subjected into Restriction Fragment Length Polymorphism (RFLP) assay.
Results: Among the 21 V. cholerae isolates, all of them (100%) were identified as V. cholerae O1 Inaba, 20 (95%) isolates were determined with El Tor biotype specificity, and 1 isolate (5%) appeared as Classical biotype. A total of 18 strains (85.8 %) contained a complete set of ACF-associated genes, 3 strains (14.2 %) were negative for ACF cluster, and all of the strains showed similar RFLP pattern to each other and to V. cholerae ATCC 14035.
Conclusion: The results showed that O1 Inaba was the dominant serotype and positive for ACF cluster in pathogenic V. cholerae isolates collected during 2011-2012 in Iran. The presence of some ACF negative strains with potentially pathogenic characteristics proposed that other colonization factors might have been involved in causing pathogenicity and diarrhea in these strains.
Volume 3, Issue 2 (5-2017)
Abstract
Background: Pseudomonas aeruginosa has become the most common cause of infections in burn patients. The aim of this study was to investigate the antibiotyping and genotyping of P. aeruginosa strains isolated from burn patients in Mottahari hospital during June-October 2016.
Materials and Methods: A total of 78 P. aeruginosa strains were collected from wound infected patients. Identification of the isolates was performed by biochemical tests and confirmed by specific 16srDNA PCR. Antimicrobial susceptibility testing was done by disk diffusion method according to the CLSI guidelines. The isolates were then evaluated for genotyping by ERIC-PCR.
Results: From a total of 78 collected isolates, 77 isolates (98.7%) were confirmed as P. aeruginosa by specific PCR. We found 4 antibiotypes. The highest resistance was observed to imipenem and gentamicin (~100%), and the most sensitivity was shown to colistin (100%). Overall, MDR phenotype was observed in most of the isolates (98.7%). The PCR of ERIC box produced 52 different patterns and 3 main clusters. Also, 59 (83%), 2 (3%), and 9 (13%) isolates were included in Cluster A, B, and C, respectively, and Cluster A was the predominant ERIC profile.
Conclusion: The high resistance to antibiotics in our study may be due to their abundant use as the prophylactic or treatment regimen in wound infections. So appropriate use of antibiotics seems necessary, and colistin is a proper choice for treatment of burn infection. In genotyping, 3 main clusters and 52 different patterns were shown. A majority of the P. aeruginosa strains isolated from burn patients were related and belonged to Cluster A.
Volume 6, Issue 3 (Summer 2020)
Abstract
Background: The outbreak of novel coronavirus (2019-nCoV), which began in Wuhan, China, has rapidly spread in many countries and is currently considered a pandemic. The virus (SARS-CoV-2) causes severe acute respiratory syndrome and is related to SARS-CoV and MERS-CoV.
Methods: In this review, an introduction to SARS-CoV-2 was provided comprising the following items: general features; pathogenesis; the existing knowledge on immunological properties; transmission routs; diagnostic features, especially discussion about new approaches for treatment and prevention; and different diagnostic methods including nucleic acid based assays, serological testing, and MALDI TOF-MS and LC-MS technologies.
Findings and Conclusion: Introducing the different methods for SARS-CoV-2 detection may be useful to provide new insights into the development and improvement of detection primers, probes, methods/techniques, potential targets for drug designation, and therapeutic candidates against the virus.
