Showing 6 results for Soltan Dallal
M.m Soltan Dallal, F Izadpour , M Khalifeh Gholi , H Zeraati , R Bakhtiari ,
Volume 4, Issue 4 (4 2006)
Abstract
Background and Aim: Yersinia is an important water- and food-borne bacterium causing gastroenteritis in humans.
Material and Methods: From December 2002 to July 2003, a total of 250 samples -including 158 meat samples and 92 chicken samples- were taken from butcheries and poultry shops operating under the supervision of Tehran University of Medical Sciences. We used a two-step enrichment procedure: phosphate buffer saline was used as primary enrichment within 3 weeks in refrigerator (cold enrichment). Then we applied KOH treatment as secondary enrichment and performed cultures on CIN agar.
Results: In this study, 44.4% of all samples showed Yersinia contamination. The prevalence of Yersinia was 29.1% in meat and 70.7% in poultry. Of the 155 Yersinia isolates, 53 (34.2%) were identified as Y. enterocolitica, 47(30.3%) as Y. intermedia, 42 (27%) as Y. fredriksenii and one (0,6%) as Y. kristensenii. Biotyping of Y. enterocolitica showed that 51 strains (39.7%) corresponded to biotype 1A, 13 strains (24.6%) to biotype 1B, one (1.8%) to biotype 2, three (5,7%) to biotype 3 and one (1.8%) to biotype 4. Fourteen strains (26.4%) could not be classified.
Conclusion: The high prevalence rates in meat and poultry implies that these products could be widely contaminated with Yersinia, thus serving as important vehicles for transmission to humans.
Mm Soltan Dallal, P Fazelifard, Sm Hosseini, F Saberpoor, F Fakharian, A Tabatabaei, S Vahedi, A Najjarian,
Volume 6, Issue 3 (13 2009)
Abstract
Background and Aims: The ready-to-eat foods, before and after preparation, usually kept in a refrigerator before consumption for a relatively long time, increase the risk of food poisoning. The aim of this study was to determine the effect of refrigeration in the fast-food shops on the microbial contamination of fast foods.
Materials and Methods: A total of 100 samples, including 46 cooked beef livers and 54 cooked sausages were collected from fast-food shops in the south of Tehran and analyzed according to the procedures of the Office of Food Control Laboratories (OFCL). The samples were tested randomly for the microbial contamination on the first, third, fifth and seventh days of storage in the refrigerator.
Results: Results of microbial analysis showed that 35 cooked sausage samples (64.8%) and 34 cooked liver samples (73.9%) on the first day, 44 cooked sausage samples (81.5%) and 42 cooked liver samples (91.3%) after the third day, 47 cooked sausage samples (87.1%) and 44 cooked liver samples (95.6%) after the fifth day, and 50 cooked sausage samples (92.3%) after the seventh day were unfit for consumption Frying of the food items before consumption would decrease, though to a small extent, microbial contamination (P<0.05). Increased total micrbial counts of the food items, exceeding the respective standards, is the most important inhibitory factor for their consumption.
Conclusion: The results of this study showed that keeping cooked foods for a long time in the refrigerator causes increased microbial contamination over time.
Mohammad Mehdi Soltan Dallal, Narges Torkashvand, Mohammad Kazem Sharifi Yazdi, Maryam Mousivand, Maryam Hashemi,
Volume 13, Issue 2 (9-2015)
Abstract
Background and Aim: Xylanases are widely used in various food industries, including livestock and poultry feed industries, the pulp and paper industry, as well as the pharmaceutical industry. Several strains of microorganisms are capable of producing this enzyme by different mechanisms, Bacilliaceae being one of its important sources at the commercial scale. The culture medium for xylan is expensive and, therefore, it is not economical to use in producing xylanase by Bacillus subtilis S7e. The purpose of this study was to explore the possibility of using industrial-agricultural wastes as a source of carbon and nitrogen in submerged fermentation, for producing xylanase in amounts higher than that which can be produced by xylan culture (10048 U/).
Materials and methods: The indigenous strain of Bacillus subtilis S7e was cultured in the xylan medium, followed by incubation at 30°, 37° and 40° C. Then the nitrogen sources (rapeseed meal, soybean meal, tomato seeds, tea seeds, peptone, Vinas alcohol, casein, and ammonium sulfate) and carbon sources (molasses, wheat bran, rice bran, rice industry waste, gluten waste, malt waste, whey powder, and bagasse) were substituted for the meat and yeast extracts and the xylan culture medium, respectively.
Results : The maximum enzyme activity was observed at 30° C after 48 hours of incubation (6183U/l). Rapeseed meal with an enzyme activity of 10048U/l and molasses with an enzyme activity of 3759U/l were found to be the best nitrogen and carbon sources for Bacillus subtilis S7e , respectively.
Conclusion: Based on the findings of this study, f rom an economic point of view, agricultural-industrial wastes (rapeseed meal and molasses) are an excellent substitute for the more expensive culture media currently in use for producing the enzyme xylanase.
Mohammad Mehdi Soltan Dallal, Rozhin Ghahremani, Abbas Akhavan Sepahi, Zahra Rajabi,
Volume 17, Issue 2 (9-2019)
Abstract
Background and Aim: Food-borne diseases, with an upward trend worldwide, are a major public health issue. On the other hand, resistance to antimicrobial agents is also a global problem. Thus, a knowledge of antibiotic resistance is vital for the proper treatment of food-borne diseases. The aims of this study were to determine the frequency, antimicrobial resistance and serotyping of Shigella-contaminted food samples in foodborne disease outbreaks in Iran.
Materials and Methods: This was a descriptive study including 1012 fecal swab samples from 239 foodborne disease outbreaks in different provinces of Iran during the period 2005-6. The isolated Shigella samples were transferred to a microbiology laboratory for microbial culture, serogrouping and antibiogram tests.
Results: Out of the1012 fecal swabs collected 29 (2.86%) isolates contained Shigella. The largest Shigella outbreaks (20.6%) were found to have ocurred in 3 provinces, namely,Esfahan, Kurdistan and Semnan. The most common clinical symptoms were abdominal cramping, vomiting, nausea and non-bloody diarrhea. Th frequency of contamination with Shigella Sonnei and Shigella flexneri was 16 (55.2%) and 13 (44.8%), repectively. The rate of resistance to ciprofloxacin was reported to be 3.4%.
Conclusion: Considering the frequency of food contamination with Shigella in the summer and its in resistence to ciprofloxacin, assessment of its antimicrobial resistance are very important as regards reduction in treatment costs and taking action to control and prevent the disease.
Mo0hammad Mehdi Soltan Dallal, Mahdiyeh Poormoradian, Sheyda Asadpour,
Volume 17, Issue 4 (3-2020)
Abstract
Background and Aim: Salmonella species is one of the important pathogens causing food poisoning and gastroenteritis. The aim of the present study was to assess the quality of traditional creams as regards bacterial contamination.
Materials and Methods: This was a cross-sectional study including a total of 250 traditional cream and 50 pasteurized cream samples collected in the south of Tehran retail shops. The samples were diluted in a phosphate-buffered saline, transferred to a rappaport-vassiliadis salmonella (rvs) enrichment broth according to the CDC procedures and incubated at 37° C in Hektoen enteric agar and bismuth sulfite agar media for 24 hours. Antimicrobial susceptibility testing was done using the Clinical and Laboratory Standards Institute (CLSI) procedures. On the following day the suspected colonies were examined for phenotype and finally confirmed by the API 20 E test.
Results: Of the 250 unpasteurized cream samples 15 (6%) were contaminated with Salmonella. Of the 7 serotypes identified, the most frequent Salmonella serotype was the infantis serotype with 7 cases (33.3%). Furthermore, Coliform bacteria such as Escherichia coli, Enterobacter, Klebsiella and Citrobacter were also isolated. The highest antibiotic resistance was to nalidixic acid (93.3%), tetracycline (73.3%) and trimethoprim (66.7%). None of the pasteurized cream samples was contaminated with Salmonella.
Conclusion: The results confirm the need for more effective control and monitoring of the traditionally prepared cream marketed in the city by the Food Control Authority. In addition, educating the public about the consumption of pasteurized cream can play a good role in reducing foodborne illnesses.
Mohammad Mehdi Soltan Dallal, Seyedeh Masoumeh Abrishamchian Langroudi , Mahdiyeh Pourmoradian, Sheyda Asadpour,
Volume 18, Issue 1 (5-2020)
Abstract
Background and Aim: Nowadays foodborne diseases are a serious concern globally. Due to unsound use of antibiotics various pathogens are involved in foodborne diseases, S. aureus being the most common cause of food poisoning. Methicillin-resistant Staphylococcus aureus (MRSA) strains are a serious threat for the public’s health worldwide. The objective of this study was to determine the extent of contamination of foods offered in the South of Tehran, Iran with MRSA strains in 2018-19.
Materials and Methods: In this descriptive study, 560 food samples were collected from different regions in the south of Tehran, Shahr-e-Rey and Islamshahr between June 2018 and May 2019 and sent to a laboratory to determine the presence of S. aureus according to the Iranian National Standard No.1194 methods. In addition, the antibiotic sensitivity of the S. aureus species was determined using the Disk Diffusion Test.
Results: Of the 560 samples, 49 (8.7%) were found to be contaminated with S.aureus. Pastry, traditional ice cream and raw protein foods were the most contaminated foodstuffs. Four 4 (8.2%) of the 49 S. aureus isolates were found to be resistant to methicillin.
Conclusion: Considering the importance of S. aureus in causing food poisoning and the possibility of transfer of species resistant to antibiotics, especially methicillin, through foods, it is vital to pay special attention to sound use of antibiotics.
