جستجوی مقالات مرتبط با کلیدواژه « ریبوتایپینگ » در نشریات گروه « پزشکی »

Clostridium difficile infection (CDI) has been a major growing problem in hospitals in recent years. Detection of the source of Clostridium difficile strains is of importance for the control of the nosocomial spread of this microorganism. This study was done to identify C.difficile isolates by polymerase chain reaction, (PCR), ribotyping. The descriptive study was done during a period of 12 month. Seventeen C.difficile isolates were collected from patients hospitalized with suspected CDI in different wards of a general hospital. All samples were treated with alcohol and yeast extract broth. The treated samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA) supplemented with 5% sheep blood and incubated in anaerobic conditions, at 37 °C for 5 days. Prevalence and confidence intervals were calculated. Cdd-3, tcdA and tcdB genes were identified using PCR assay. PCR ribotyping was performed on C.difficile isolates. Out of 108 isolates 17(15.7%) were C.difficile. The prevalence of A+B+, A+ B- and A- B+ strains were 12(70.59%), 1(5.9%) and 4(23.9%) respectively. PCR ribotyping of 17 isolates showed different ribotype patterns The pattern of PCR ribotypes of isolates showed that the strains circulating in different wards of the hospital were different and may have been be endogenous or community acquired.

Salmonella spp. are enteric pathogens with a worldwide distribution comprising a large number of serovars characterized by different hosts and distribution. Among Salmonella spp., the number of infections and diseases caused by the serotype Salmonella enterica serovar Infantis started to increase significantly in the last decade. The aim of this study was to investigate the genetic diversity of the clinical stains of Salmonella enterica serovar Infantis isolated in Tehran, Iran by using the Ribotyping method. In this descriptive study from November 2007 to December 2010, clinical samples, collected from different hospitals in Tehran, were investigated for detection of Salmonella enterica serovar Infantis. Bacterial isolation and identification was achieved through biochemical and bacteriological methods. The Ribotyping technique was applied for the molecular typing of the strain of Salmonella enterica serovar Infantis. Out of the 26 Salmonella serogroup C samples isolated in this study, 19 strains (73%) belonged to Salmonella enterica serotype Infantis. Ribotyping results divided Salmonella enterica serovar Infantis stains into 9 clusters (1c to 9c). The majority (7) of the strains belonged to cluster 1c. The results obtained from the Ribotyping patterns indicate that Salmonella enterica serovar Infantis strains, circulating among the patients in Tehran, belong to a diverse number of clones. Moreover, our data show that Ribotyping is an appropriate method for the molecular typing of Salmonella enterica serovar Infantis strains.

Salmonella enterica serovar enteritidis is currently the most frequent serovar causing salmonellosis in humans. The incidence of gastrointestinal infections caused by S. enteritidis increased during the last decade. The aim of this study was to evaluate the genetic diversity of S. enteritidis isolates from Tehran (Iran) hospitals using ribotyping methods. In a descriptive study from April 2008 to December 2011, clinical samples such as fecal and blood specimens of the cases having symptoms of salmonellae infection were collected from different hospitals in Tehran. Salmonella isolation was carried out by bacteriological and serological methods. The relationship between the strains was determined using ribotyping. Of 68 Salmonella spp. strains, 29 isolates were S. enteritidis. Ribotyping was able to differentiate all isolates. The size of the bands ranged from 1.4 to 16.8 kb in all ribotypes. S. enteritidis isolates were divided into three clusters (1d to 3d). Most strains (20) belonged to the 1d cluster. Our results indicated that S. enteritidis strains circulating in Tehran mainly belong to a limited ribotype.

Microbial strain typing is an integral part of epidemiological investigations of infectious diseases. This process is important epidemiological for recognizing outbreaks of infection, detecting the cross-transmission of nosocomical pathogens, determining the source of the infections, recognizing particularly virulent strains of organisms, and evaluation of control measurcs. Typing methods fall lnto two broad categories: phenotypic and genotypic methods. Phenotypic methods are rely on the expression of particular properties belonging to the organism and have a tendency to vary. Genotyping methods are based on analysis of the genetic material of a microorganism and less subject to natural variation. In recent years, several molecular techniques have emerged as choice methods for microbial typing. Molecular typing methods have several advantages over traditional approaches, including higher discriminatory power, broader application to a variety of microbial species, at times, and speed. In this review, some of the most current techlology particularly molecular typing methods for microbial typing with regard to the principles of the methods and their reproducibility, discrimination power, and ease of use, are compared.