Search published articles


Showing 2 results for Coagulase
Prevalence of coagulase-negative staphylococci and determination of antimicrobial resistance in accompany with types of SCCmec in isolated of nosocomial infections
Mohammad Reza Arabestani , Mohammad Yousef Alikhani , Manoochehr Karami , Elham Salimi Ghale ,
Volume 73, Issue 12 (3-2016)
Abstract

Background: Coagulase-negative staphylococci (CoNS) were considered as contaminats previously, but, during the past decade considered as one of the most common photogenic bacteria in hospital. Resistance to beta-lactams especially methicillin in staphylococcus species is being worrying in hospitals. Rapid identification of mechanisms of resistance and confirmation of their resistance to methicillin is a basic principle for antibiotic treatment. The aim of this study was to determine antibiotic resistance, frequency of mecA gene, and determination of SCCmec types in CoNS isolates from teaching hospitals in Iran.

Methods: The descriptive cross-sectional study was carried out one hundred clinical samples isolated from patients with an average age of 7-69 years at teaching hospitals in Hamadan City, Iran, from September 2014 to February 2015. After confirmation of isolates by microbiological standard biochemical tests, antimicrobial susceptibility testing was performed by disk agar diffusion (DAD) method. After extraction of isolated genomicm, mecA gene was detected. Then, the types of SCCmec were performed by PCR.

Results: In this study, 387 clinical samples were collected which among 100 CoNS isolated, Staphylococcus epidermidis was the most prevalent species with frequency 55 (55%), followed by S. haemolyticus 40(40%) and S. saprophyticus 5(5%). The highest antibiotic susceptibility was to rifampin 96(96%) and the lowest resistance was detected for trimethoprim/sulfamethoxazole (TMP/SMX) 47(47%). None of the strains were resistant to vancomycin. Resistance to methicillin was detected in 50% of CoNS isolates. Typing of SCCmec was performed by The polymerase chain reaction (PCR). Frequency types of SCCmec was type III with frequency 13(13%), type V 11(11%), type II 6(6%), type IV 4 (4%), type I 3(3%) respectively. Thirteen isolated was not typable in this study.

Conclusion: The result of this study showed that a large percentage of coagulase-negative staphylococci are resistance to methicillin, and the prevalence of SCCmec type was type III, which encodes the largest number of resistance genes. This information could be use in epidemiological study for preventing of infectious control in hospital and health centers.


Genetic diversity of Staphylocoagulase genes (Coa) among methicillin-resistant Staphylococcus aureus isolates at clinical specimens of blood and urinary infections
Mehrdad Mohammadi, Jamshid Faghri,
Volume 77, Issue 4 (7-2019)
Abstract
Background: Staphylococcus aureus is a common pathogen in human that can be the cause of a wide range of infectious diseases including bacteremia, pneumonia, cellulitis, and osteomyelitis and skin and soft tissue infections. The coagulase enzyme is one of the most important virulence factors of this bacterium. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) Coa pattern is one of the molecular base typing methods. Molecular typing plays an important role in epidemiological studies of nosocomial infection, such as methicillin-resistant Staphylococcus aureus (MRSA) infection. The PCR-RFLP Coa gene technique provides a useful preliminary method to monitor variations in MRSA populations. We were done Coa-RFLP typing according to the method of Hookey et al., with some modifications.
Methods: In this cross-sectional study, one-hundred fifty isolates of S. aureus from urine and blood samples of patients that collected from educational hospitals of Imam Hossein and Al Zahra Isfahan University of Medical Sciences, Iran, from February 2018 to October 2018 were analyzed. After bacterial confirmation of isolates by Coa gene in polymerase chain reaction (PCR) technique, to perform coagulase gene typing, the repeated units encoding hypervariable regions of the coagulase gene of S. aureus were amplified by PCR. This was followed by AluI restriction enzyme digestion and analysis of restriction fragment length polymorphism (RFLP) patterns.
Results: Of 150 samples, 45 isolated of S. aureus were confirmed by biochemical methods. Of previous positive samples, 36 (80%) isolates carried Coa gene. Two different genotypes of Coa gene were obtained that include bp680 fragment in 20 specimens and bp750 fragment in 16 specimens. After enzymatic digestion by AluI restriction enzyme for RFLP, four different restriction patterns were obtained that including, the 280+400 pattern in 16 specimens (44.4%), 280+470 pattern in 7 specimens (19.4%), 340+340 pattern in 6 specimens (16.6%) and 750 patterns without digestion were in 7 specimens (19.6%).
Conclusion: Using the present experiments, it was determined that the PCR-RFLP pattern, 280+400, was the dominant pattern in the Staphylococcus aureus samples isolated in Isfahan.

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by : Yektaweb