[show abstract][hide abstract] ABSTRACT: Background: Helicobacter pylori, which is associated with many upper gastrointestinal diseases, is found in half of the population of the world. Several special stains and immunohistochemistry stain for H. pylori are available. The need for and usefulness of immunohistochemical (IHC) technique has been debated for years. Toluidine blue is a simple stain for microbiological studies and is easily available in laboratories. Therefore, this study was conducted to compare hematoxylin and eosin (H&E), Giemsa and toluidine blue staining with immunehistochemistry for detection of H. pylori in patients with gastritis and also to correlate the results of these staining methods with pathological grading. Methods: We reviewed 54 consecutive gastric biopsy specimens stained by H&E and Giemsa as well as by toluidine blue and immunohistochemistry stains for H. pylori. Results: H. pylori was positively identified by IHC in 43 (79.63%) patients, while positive samples were found in 18 (33.33%), 24 (44.44%) and 33 (61.11%) patients using H&E, Giemsa and toluidine blue staining methods. Our results showed that classical histological staining methods are not sensitive enough to identify low numbers or coccoid forms of organism, while toluidine blue and immunohistochemistry play an important role in detection of H. pylori infection. Conclusion: Toluidine blue has been proved to be much more reliable than H&E and Giemsa in detection of H. pylori. In addition, in post treatment biopsies and in biopsies with unexplained chronic active gastritis without histological evidence of H. pylori should have immunohistochemistry done to detect possible low density or coccoid form of organisms.
[show abstract][hide abstract] ABSTRACT: The aim of this study was to understand the epidemiological linkage of clinical and environmental isolates of Vibrio cholerae and to determine their genotypes and virulence genes content.
A total of 60 V. cholerae strains obtained from clinical specimens (n = 40) and surface waters (n = 20) were subjected to genotyping using PFGE and determination of their virulence-associated gene clusters.
PCR analysis showed the presence of chromosomally located hly and RTX genetic elements in 100% and 90% of the environmental isolates, respectively. The phage-mediated genetic elements such as CTX, TLC and VPI were detected in 5% of the environmental isolates suggesting that the environmental isolates cannot acquire certain mobile gene clusters. A total of 4 and 18 pulsotypes were obtained among the clinical and environmental V. cholerae isolates, respectively. Non-pathogenic environmentally isolated V. cholerae constituted a distinct cluster with one single non-O1, non-O139 strain (EP6) carrying the virulence genes similar to the epidemic strains. This may suggest the possible potential of conversion of non-pathogenic to a pathogenic environmental strain.
The emergence of a single environmental isolate in our study containing the pathogenicity genes amongst the diverse non-pathogenic environmental isolates needs to be further studied in the context of V. cholerae pathogenicity sero-coversion.
Indian journal of medical microbiology 07/2012; 30(3):285-9.
[show abstract][hide abstract] ABSTRACT: In this study 86 isolates of Vibrio cholerae were analysed for their adhesive properties and the presence of pathogenicity island genes. With the exception of three isolates, all of the other clinical isolates (92.5%) contained an intact TCP (toxin-co-regulated pilus) gene cluster. In contrast, 95% of all environmental non-O1-non-O139 isolates were negative for the TCP gene cluster. The majority of clinical isolates (82.5%) possessed the complete vibrio pathogenicity island (VPI) gene cluster and had a similar RFLP pattern, while only a single environmental strain possessed an almost complete VPI cluster (lacking 0.4 kb in the tcpA and toxT region). The result showed that the isolates with tcpA(+)/toxT(+) had a strong attachment for HT-29 and Vero cells, whereas isolates with tcpA(+)/toxT(-) or tcpA(-)/toxT(-) genomic characteristics showed no autoagglutination and weak attachment for the cell lines. Two environmental strains (tcpA(-)/toxT(-)) showed strong adhesive properties to the cell lines, indicating that non-fimbrial adhesive factors are involved in the environmental V. cholerae strains in the absence of TCP.
Journal of Medical Microbiology 08/2011; 60(Pt 12):1742-9. · 2.30 Impact Factor
[show abstract][hide abstract] ABSTRACT: The aim of the study was to examine the epidemiological characteristics of hospitalized burn patients in a tertiary burn centre in Tehran, Iran. A hospital-based cross-sectional study of all hospitalized patients with burn injuries was conducted in Motahari Burn and Reconstruction Center in Tehran from August to December 2010. Medical records of all hospitalized burn patients were reviewed and pertinent information was captured. A total of 135 patients with severe burns requiring hospitalization were identified during the study period (68.9% males, mean age 33 yr). The most common cause of burns was flammable materials/ liquids (e.g. kerosene and gasoline) (56/135, 41.5%). Binary logistic regression analysis showed that sex (female) and total body surface area (TBSA) burned were the strongest predictors of survival in this cohort. Our findings showed that burn injury continued to be a significant public health problem in Iran, young people (26-35 yr) being the most affected. TBSA and sex (female) were found to be the most predictive factors of patient survival.
Annals of burns and fire disasters. 06/2011; 24(2):59-62.
[show abstract][hide abstract] ABSTRACT: The aim of this study was to investigate the presence of TCP gene clusters among clinical and environmental Vibrio cholerae isolates and to explore the genetic relatedness of isolates using ribotyping technique. A total of 50 V. cholerae strains (30 clinical and 20 environmental) were included in this study. Three clinical isolates were negative for TCP cluster genes while the cluster was absent in all of the environmental strains. Ribotyping of rRNA genes with BglI produced 18 different ribotype patterns, three of which belonged to clinical O1 serotype isolates. The remaining 15 ribotypes belonged to clinical non-O1, non-O139 serogroups (two patterns) and environmental non-O1, non-O139 serogroups (13 patterns). Clinical V. cholerae O1 strains from 2004 through 2006 and several environmental non-O1, non-O139 V. cholerae strains from 2006 showed 67.3 % similarity and fell within one single gene cluster. Ribotyping analysis made it possible to further comprehend the close originality of clinical isolates as very little changes have been occurred within rRNA genes of different genotypes of V. cholerae strains through years. In conclusion, ribotyping analysis of environmental V. cholerae isolates showed a substantial genomic diversity supporting the fact that genetic changes within bacterial genome occurs during years in the environment, while only little changes may arise within the genome of clinical isolates.