Escherichia coli, Shigella and Salmonella species in acute diarrhoea in Hamedan, Islamic Republic of Iran

This study investigated the frequency of Escherichia coli, Shigella and Salmonella species in stool specimens from patients with diarrhoea presenting to health centres in Hamedan province, Islamic Republic of Iran. From 144 samples, Shigella strains were isolated in 17 cases [11.8%]: 10 Sh. flexneri, 3 Sh. sonnei, 2 Sh. boydii and 2 untyped strains. No Salmonella strains were isolated. Using molecular diagnostic methods, diarrheogenic E. coli were detected in 37 cases [25.7%], the majority were enterotoxigenic [ETEC] [22 cases] and Shiga toxin- producing [STEC] strains [15 cases]. In 14 cases [9.7%] there was co- infection

[Determining the prevalence of Salmonella serotypes obtained from meat and chicken samples and their antibiotic resistance pattern in Tehran]

Food borne diseases are still the major problem in both industrial and nonindustrial countries and the prevalence of these diseases are on rise. Consuming of contaminated meats with Salmonella is the major source for distributing these diseases. Adding antibiotics in domestic animals' food causes antibiotic resistance so the resistant bacterium could be transfer to the human through the consumption of such foods. The aim of this study was to determine the Salmonella serotypes, and antibiotic resistance of isolated serotypes obtained from packed and non- packed meat and chicken purchased in different districts of Tehran, during 2004 and 2005. In this cross-sectional study, samples were taken randomly from 10 packaged meat suppliers and 17 non-packaged meat suppliers. Out of 133 prepared samples, 67 ones were chicken and 66 samples were meat. Samples were weighted, separated [each 25gr] and put into 225ml of Buffered Peptone Water. Then homogenized by Stomacher and incubated at 37[o]c for 24 hours. After that 0.1 ml of solution poured into 10 ml of Rappaport Vassilidis broth and remained 24 hours in 42[o]c. Then, one loop of this medium was cultured on Hektoen Entro Agar and remained for a period of 24 hours in 37[o]c to enter Salmonella colonies. For the antibiotic sensitivity test, the agar disc diffusion was used according to the standard method. Out of 67 tested samples of chicken, 32 samples [47.8%] were contaminated with Salmonella, as well as 19 meat samples [28.8%] [from the total 66 ones]. The dominated serotype of both chicken and meat samples was S.thompson [54.6%]. The results of antibiotic susceptibility showed that 90.6% of isolated chicken samples were resistant to Nalidixic acid, compared to 36.8% of meat samples. According to the observed antibiotic resistance in some of tested samples, special attention in quality control of food's safety in order to prevent the related diseases is needed