A total of 114 samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and coliphages. Sorbitol MacConkey agar is mainly used in the detection of E. coli O157:H7. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of 20 different genera, 38 species of non-sorbitol fermenting bacteria were isolated. Escherichia coli O157 could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O157. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals` wastewaters samples. The correlation between coliphages and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O157, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries.

Introduction and Objectives: E. coli O157:H7 form colorless colonies on SMAC and may be distinguished from intestinal flora. Some Enterobacteriaceae present in gut, also grow on SMAC and are difficult to differentiate and diagnose. Therefore modification and improvement of SMAC medium is necessary to select E. Coli O157. The aim of this study is to improve this medium in order to differentiate this bacterium better.Material and Methods: 250 fecal swab sheep slaughtered in slaughterhouses Shiraz to isolate the bacteria E. coli O157 was selected. Prepared SMAC plates containing from 0.05 mg L-1 ceffexime and 2.5 mg L-1 potasium tellurite as standard (1S) to 6 time standard (6S). Certain pure E. coli O157 EDL933 was plated on SMACs. All plates incubated in 37°C over night. Results: E. coli O157 was grown on all six SMACs, but all plates had grown with the same count in 1S to 3S plats. Some bacteria decreased according to dose of antibiotics. Two and four percent contamination rate was shown high sensitivity in 3 S than 1 S. use of media with high antibiotic deleted extra intestinal bacteria.Conclusion: We recommend using ICT-SMAC medium supplemented with 1.5 and 7.5 mg L-1 ceffexime and potassium tellurte respectively in spite of current SMAC to isolate E. coli O157 from clinical case.

Background: E. coli O157: H7 is one of the intestinal pathogens which causes serious lesion in gastrointestinal system. Detection of this bacteria that able to produce toxin and is the major responsible for hospital infection, usually done by culture on sorbitol-MacConkey agar which is time-consuming test. The aim of this study was the preparation a fast and precise method in order to identification of this bacterium by molecular method based on PCR technique. Material and Methods: rfbE and stx2b genes were selected for proprietary identification of E. coli O157: H7 and the amplification of them were performed by PCR following designing specific primers. Sorbitol-MacConkey agar was used to verification of growth ability of selected colonies during PCR. Results: By appearance of the bonds belong to rfbE and stx2B genes on agarose gel, the ability of designed primers in gene detection in samples of E. coli O157: H7 was verified. Colonies which selected during PCR have growth potency on sorbitol-MacConkey agar medium. Conclusion: It was revealed that we can prepare a fast, precise and relative comfortable method for detection of E. coli O157: H7 strain by using PCR technique and specific primers than other available methods.

Escherichia coli O157:H7 is an important human pathogen causing haemorrhagic colitis, haemolytic-uraemic syndrome and thrombotic thrombocytopenic purpura. In this study, 100 ground beef samples were collected randomly from beef markets in June 2004. For isolation of the bacteria, samples were firstly enriched in modified trypticase soy broth, followed by plating onto sorbitol MacConkey agar supplemented with cefixime and potassium tellurite. Consequently, the suspected non-sorbitol fermenting (NSF) colonies were confirmed by biochemical tests and employed for polymerase chain reaction (PCR) assay, using primers specific for O157 and H7 antigens gene. In this study, 7 NSF E. coli colonies were isolated; in PCR assay only one of them confirmed as E. coli O157:H7. The PCR assay employed in this study may be a possible alternative to immunological assays which detects somatic and flagellar antigens.

Background: Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen and infection with this organism causes illnesses such as bloody diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome.Objectives: Considering the lack of any information about the prevalence rate and the antibiotic resistance pattern of O157:H7 serotype in Tabriz, finding answers to the above mentioned subjects was among the goals of this study.Materials and Methods: Two hundred E. coli strains from diarrheal or non-diarrheal stools of outpatients and hospitalized cases in Tabriz Imam Reza hospital were isolated between September and December 2014 using MacConkey agar and standard biochemical tests and then cultured on sorbitol MacConkey agar. The sorbitol-negative isolates were confirmed as the O157 serotype using O157 antisera. A multiplex polymerase chain reaction (PCR) method was used for the detection of stx-1, stx-2, eae, and mdh genes and the antibiotic resistance pattern of these isolates was determined using Kirby-Bauer method and clinical and laboratory standards institute (CLSI) standards.Results: Of the isolates 11 (5.5%) were sorbitol-negative, which were later analyzed by multiplex PCR and the results revealed that 2 (18.18%) isolates contained the stx-1 gene, 10 (90.91%) contained the stx-2 gene, and 5 (45.45%) contained the eae gene. The stx-2 and eae genes were the most commonly encountered virulence factors. All or most of the isolates were susceptible to ceftazidime (100%), gentamicin (100%), ciprofloxacin (100%), nalidixic acid (90.9%), trimetoprim sulfamethoxazole (90.9%), chloramphenicol (90.9%), ampicillin (81.8%), and cephalothin (72.7%). On the contrary, moderate susceptibility of the isolates to doxycycline (54.5%) was observed.Conclusions: Due to the low frequency of STEC O157 and the high susceptibility rates of the isolates to the tested antibiotics in this study, STEC O157 has not become a major problem in Tabriz yet, but comprehensive microbiological surveillance programs that provide early warning and limit the scale of possible outbreaks would be essential.

Objective: The general purpose of this study was to evaluate a new chromogenic medium "Candida ID agar" for identification of Candida species and compare it with Candida CHROM agar.Materials and methods: 150 clinical samples were cultured on Candida ID agar and Candida CHROM agar. The isolated yeasts were also identified using APi kit system and the results compared with Candida ID agar and Candida CHROM agar using laboratory test evaluation formula.Results: The sensitivity of Candida ID agar was 96.4% which was more than that in Candida CHROM agar of 51% especially for Candida albicans.Conclusion: Candida ID agar was more useful for identification of Candida albicans and differentiation of other Candida species in compare with CHROM agar.

Data describing the microbiological status of a country’s meat products can be of great value: in acting as a de facto validation of the country’s regulatory systems, as a baseline for setting performance standards and in supporting risk assessment. O26, O45, O91, O103, O111, O113, O121, O128, O145, and O157 are the most common serotypes of enterohemorrhagicEscherichia coli associated with human disease. Considering the importance of what mentioned and the potential ability of sheep meat to transmit enter hemorrhagic E. coli to humans, the present study was conducted to evaluate sheep meat contamination toE. coli and E. coli O157, O26 and O128 serotypes in Shahrekord by PCR. Altogether 135 samples of sheep carcasses were collected from Jooneghan abattoir, Chaharmahalvabakhtiari, Iran. Samples enriched in Tryptone Soya Broth (TSB). Then, incubated broth culture was streaked onto Sorbitol MacConkey agar and MacConkey agar as selective plating media. Suspected colonies were tested by polymerase chain reaction. The contamination rate in sheep carcasses with E. coli was 50.37% (68 out of 135).1.48% (2 out of 135) of the samples was contaminated with E. coli O128. E. coli O157 and O26 were not found in any samples.Present study suggests E. coli O157 and O26 are not prevalent in the region.

In this study 130 bulk tank milk samples which were delivered to the Pegah Pasturisation Factory in Mashhad were collected randomly during the summer months. Samples were firstly enriched in modified trypticase soy broth containing novobiocin, followed by plating onto sorbitol MacConkey agar supplemented with cefixime and potassium tellurite for isolation of Escherichia coli O157:H7. Consequently the suspected non-sorbitol fermenting (NSF) colonies were confirmed by biochemical tests as Escherichia coli and then were used for multiplex-PCR assay, using primers specific for O157 and H7 antigens genes and then primers specific for stx1 and stx2 genes. NSF Escherichia coli colonies were recovered from 8 samples, and in multiplex-PCR assay one sample (0.77%) was confirmed as Escherichia coli O157:H7. The second multiplex PCR assay showed that the isolate was harboring the stx2 gene. The PCR assay used in this study may be a possible alternative to immunological assays which detect somatic and flagellar antigens. Besides, this procedure determines the potential of isolates for toxin production.