[ frequency of toxigenic strains of Clostridium difficile in hospitalized patients with diarrhea in Tehran/Iran by PCR method, 2010]

Clostridium difficile has been identified as a pathogen in antibiotic associated diarrhea [AAD], pseudomembranous colitis and also nosocomial diarrhea. The present study was performed to find the prevalence of toxigenic strains of C .difficile isolated from diarrhea patients hospitalized in Tehran hospitals. A total of 98 fecal samples obtained during July to December 2010 were studied. Samples were rapidly cultured on the CCFA medium and incubated at the anaerobic conditions. Then ELISA was done to detect toxin A and B in the stool. Molecular identification of C.difficile was done by cdd3 universal primer and toxin A gene [tcdA], toxin B gene [tcdB] and binary toxin profiles were determined by PCR method. From a total of 98 fecal samples, 15 samples [15.3%] were positive of which, 12 strains [21.2%] were A+B+, 2 strains [2%] were A+B-, and 1 strain [1%] was A-B+. This study showed that Clostridium difficile is an important pathogen in the development of nosocomial diarrhea. Therefore, routine detection of C.difficile in suspected cases is recommended

Fatal sepsis by Bacillus circulam in an immunocompromised patient

An immunosuppressed man was admitted to hospital with diarrhea and a history of urinary tract infection. He was subjected to treatment with antibiotics. The patient died of putative severe sepsis. The etiological agent was a carbapenemase producing isolate of Bacillus circulans with resistance to all prescribed antimicrobial agents

[Differentiation of Entamoeba histolytica and Entamoeba dispar by single polymerase chain reaction]

In most part of the world detection of cysts and trophozoites of Entamoeba is based on morphological structure of this species in stool sample by microscopy. However, microscopic examination is unable to distinguish between similar morphological protozoa such as Entarnoeba histolytica and Entamoeba dispar. A simple and cost-effective method is needed in medical laboratories for detection and differentiation of these two species. Stool samples of patients who were referred from health care centers were examined by direct microscopy and trichrome stain. Polymerase chain reaction [PCR] utilizing pEd30F and pEd21AS primers from Peroxiredoxin gene, was used for differentiation of E. histolytica and E. dispar. Genomic DNA from samples was amplified by these primers. The fragment under 100 bp was related to E. histolytica and in contrast the fragment above the 100 bp was related to E. dispar. In this study from 22 microscopic positive samples, E. histolytica was observed only in one patient and E. dispar was detected in the other 21 samples. The result of this study indicate that the PCR reaction could amplify E. dispar and E. histolytica with just one primer pair and this is a cost-effective method for distinguishing between these two species

Prevalence of Entamoeba histolytica and Entamoeba dispar in gonbad city, 2006, Iran

Differential diagnosis of two protozoan parasites Entamoeba histolytica and E. dispar is of great clinical and epidemiological importance, but except in the case of haematophagous trophozoites in acute dysentery, it is not possible to differentiate them by microscopy. The present study was carried out from February 2005 to July 2006 in order to determine the prevalence of E. histolytica and E. dispar in Gonbad City, by using a PCR method. Five hundred and sixty four fecal samples were collected from primary health care centers of Gonbad both urban and rural areas. The stool specimens were examined by light microscopy [Direct slide smear, Iodine wet mount, Formal-ether concentration and Trichrome staining] to distinguish E. histolytica/E. dispar complex and differentiate them from other non-pathogenic intestinal amoebae. The microscopy results of stool exams showed a frequency rate of 23 positive samples [4.07%] for cyst of E. histolytica/E. dispar complex. All the microscopy positive isolates appeared to be infected with cyst of E. histolytica/E. dispar complex were cultivated and maintained successfully in HSr + s medium for DNA extraction and identification by the PCR method. The PCR study showed that 16 isolates [69.56%] of the Entamoeba samples were E. dispar while 7 samples [30.43%] of those microscopy positive samples were not amplified and none of them showed E. histolytica pattern. High frequency rate of E. dispar in this study were in high agreement with the estimation rate of these entamoebas worldwide

[Consideration sensitivity of PCR-Ribotyping method in identification Salmonella spp isolates from patients with diarrhea]

Background: Salmonella is the most important diarrheagenic pathogens, which can cause food borne disease where the main route of transmission among human is through contaminated meat and poultry foods. Its symptoms can be diarrhea, fever, vomiting and sometimes bloody diarrhea. For it's importance, it is essential to be identified and characterized by more precise methods such as molecular techniques. The aim of this study was to consider sensitivity of PCR-Ribotyping method for identification of Salmonella spp

Materials and methods: in this study our samples were Salmonella strains, which were isolated from patients with diarrhea. Their DNA was extracted by phenol/ Chloroform method. We did PCR-Ribotyping method with P1, P2 primers for 16S-23SrRNA gene. At last PCR-products run on 1.8% agarose gel in 120V for 90 min. the analysis was done after Ethidium bromide staining

Results: all the 40 strains containing paratyphi A, B, C and D serotypes also, serotype typhi contained 5 bands ranging 700 to 2500 bp

Conclusions: according to the results we can say that PCR-Ribotyping method has the highest sensitivity for identification of genus Salmonella but it is not suitable for Serotyping of Salmonella strains