Search

BACKGROUND AND OBJECTIVE: Lactobacilli are gram positive, catalase-negative, and found in a variety of fermented foods such as honey, as well as human normal flora. The aim of this study was to identify lactobacillus Plantarum and lactobacillus Paracasei in Iranian honey samples and to investigate the probiotic and antimicrobial properties of them against Staphylococcus aureus. METHODS: This cross-sectional study investigated 88 honey samples from different areas in Iran at 6 months, from May to September, 2016. Samples were cultured in MRS broth and after were cultured on MRS agar. Sequencing of 16S rDNA gene was used to detect lactobacillus isolates. Then probiotic capacity (acid and bile resistance) of isolates was measured. Antimicrobial activity of lactobacillus isolates was investigated by diffusion method from wells and antibiotic resistance by disc diffusion method. FINDINGS: From 88 honey samples, 39 Lactobacillus isolates were isolated, four L. plantarum and two L. paracasei were identified by molecular technique. Every six isolates tolerated acidity but were sensitive to bile salt. Five isolates inhibited the growth of S. aureus. The most antibiotic resistance of Lactobacillus strains was seen to vancomycin(100%), nalidixic acid(100%) and streptomycin(100%). CONCLUSION: Iranian honey samples can be a source for different Lactobacillus species as L. plantarum and L. Paracasei which some of these species could have wonderful inhibitory effects against pathogen bacteria like S. aureus.

Background and Aim: Group B streptococcus(GBS)(Streptococcus agalactiae) is the leading cause of morbidity and mortality of the newborn infant and accounted as a factor leading septicemia after birth in mothers. Infections in infants are usually acquired by contact with the genital tract of the mother during labor and delivery. So a rapid screening test for group B streptococcus that could accurately identify pregnant women who are carrying the bacteria at the time of delivery would obviate the need for prenatal screening.The goal of this study was molecular epidemiology of group B beta Hemolytic Streptococcal(GBS) colonization in the vaginal flora of pregnant women. Materials and Methods: Samples were taken from mucus of anal and vaginal of 250 pregnant women during 35-37 weeks ingestion by swap. Samples were tested by standard culture using Todd Hewitt Broth and Blood Agar and also by PCR using cfb gene.Results: Culture identified 21(8.4%) women as carriage of GBS from 250 women but PCR assay could identify 24(9/6%) women. In comparison to culture results, sensitivity, NPV Specificity PPV of PCR Were(100%, 100% and 97%, 82%) respectively. The times that used for PCR assay and culture were 2h and 36h respectively. Conclusion: In conclusion, we found that group B streptococci can be detected rapidly and reliably by a PCR assay of combined vaginal and anal secretions from pregnant women at the time of delivery. Also this study shows that incidence of GBS is at high rate in Iranian pregnant woman, so we recommend screening of pregnant woman for detecting of GBS emphatically.

Background and Aim: Group B streptococcus(GBS)(Streptococcus agalactiae) is the leading cause of morbidity and mortality of the newborn infant and accounted as a factor leading septicemia after birth in mothers. Infections in infants are usually acquired by contact with the genital tract of the mother during labor and delivery. So a rapid screening test for group B streptococcus that could accurately identify pregnant women who are carrying the bacteria at the time of delivery would obviate the need for prenatal screening.The goal of this study was molecular epidemiology of group B beta Hemolytic Streptococcal(GBS) colonization in the vaginal flora of pregnant women. Materials and Methods: Samples were taken from mucus of anal and vaginal of 250 pregnant women during 35-37 week's ingestion by swap. Samples were tested by standard culture using Todd Hewitt Broth and Blood Agar and also by PCR using cfb gene. Results: Culture identified 21(8.4%) women as carriage of GBS from 250 women but PCR assay could identify 24(9/6%) women. In comparison to culture results, sensitivity, NPV Specificity PPV of PCR Were(100%, 100% and 97%, 82%) respectively. The times that used for PCR assay and culture were 2h and 36h respectively. Conclusion: In conclusion, we found that group B streptococci can be detected rapidly and reliably by a PCR assay of combined vaginal and anal secretions from pregnant women at the time of delivery. Also this study shows that incidence of GBS is at high rate in Iranian pregnant woman, so we recommend screening of pregnant woman for detecting of GBS emphatically.

Background and Aim: Enteroinvasive Escherichia coli (EIEC) strains include a group of diarrheagenic Escherichia coli (DEC) and are known to cause shigellosis-like symptoms in both adults and children. They belong to a limited number of serotypes and their somatic (O) antigens are identical with, or related to, certain Shigella antigens. EIEC strains are confirmed by demonstration of invasiveness by polymerase chain reaction (PCR) for detection of the ipaH (invasive plasmid antigen H) gene that is specific for these strains among DEC.Since in our country,Iran study for detection of these strains. hasnot been carried out therefore the aim of this study was detection of EIEC in diarrheal under 5 year old children in Tehran.Materials and Methods: During the descriptive study,300stool samples were collected from children with diarrhea in Ali Asghar Hospital and children medicinal center of Tehran during 4 months (April-Jul 2008). E.coli species were isolated by standard bacteriological and biochemical tests. Presence of invasive plasmid antigen H (ipaH) gene in confirmed colonies was investigated by PCR technique.Results: Among 300 stool specimens studied using culture method and biochemical tests,39(13%) E.coli species were isolated. Among these 39 strains,7(2.3%) strains containing ipaH gene (EIEC) were detected by PCR technique.Conclusions: Enteroinvasive Escherichia coli (EIEC) in our country, Iran, may be as bacterial pathogen causing childhood diarrhea. Therefore we should apply new techniques for investigation of these strains.

Background and Aim: Enteroinvasive Escherichia coli (EIEC) strains include a group of diarrheagenic Escherichia coli (DEC) and are known to cause shigellosis-like symptoms in both adults and children. They belong to a limited number of serotypes and their somatic (O) antigens are identical with, or related to, certain Shigella antigens. EIEC strains are confirmed by demonstration of invasiveness by polymerase chain reaction (PCR) for detection of the ipaH (invasive plasmid antigen H) gene that is specific for these strains among DEC.Since in our country,Iran study for detection of these strains. hasnot been carried out therefore the aim of this study was detection of EIEC in diarrheal under 5 year old children in Tehran. Materials and Methods: During the descriptive study,300stool samples were collected from children with diarrhea in Ali Asghar Hospital and children medicinal center of Tehran during 4 months (April-Jul 2008). E.coli species were isolated by standard bacteriological and biochemical tests. Presence of invasive plasmid antigen H (ipaH) gene in confirmed colonies was investigated by PCR technique. Results: Among 300 stool specimens studied using culture method and biochemical tests,39(13%) E.coli species were isolated. Among these 39 strains,7(2.3%) strains containing ipaH gene (EIEC) were detected by PCR technique. Conclusions: Enteroinvasive Escherichia coli (EIEC) in our country, Iran, may be as bacterial pathogen causing childhood diarrhea. Therefore we should apply new techniques for investigation of these strains.

Introduction: Shiga toxin- producing Escherichia coli (STEC) is an emerging bacterial pathogen in developing countries that causes several diseases such as diarrhea, hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS), particularly in children. Aim of the research was detection of STEC in diarrheal specimens from under 5 year olds and study of the patterns of antibiotic resistance of these strains. Methods: In the study,300 fecal samples were collected from children with diarrhea referring to Ali Asghar Hospital. E.coli species were isolated by standard bacteriological and biochemical tests. Presence of shiga toxin genes (stx1/2) was investigated by PCR technique (Qiagen). Antibiogram test for strains containing the toxin gene was performed using 16 different antibiotic discs (MAST) by disc diffusion agar (Kirby-Bauer) method. Results: From 39 E.coli isolates, 9(23.1%) strains were detected by PCR to contain stx1/2 gene. One strain was resistant to all 16 antibiotics. All the STEC strains were sensitive to meropenem (MRP), imipenem (IMI), gentamycin (GEN) and nitrofurantoin (NI). 4(44.44%) strains showed multi-drug resistant pattern. All these 4strains were resistant to cotrimoxazole(SxT). Also, 6(66.66%) strains were resistant to at least one antibiotic. Conclusion: In Iran, shiga toxin- producing Escherichia coli (STEC) may be a commonly bacterial pathogen causing diarrhea, particularly in children. Therefore, we should use new techniques for investigation of these strains. Increase in number of emerging and new strains that could be resistant to classic antibiotics such as cotrimoxazole may be foreseen. It is suggested that antibiotics prescription programs in treatment of diarrhea causing E.coli strains be updated.

Background and Aim: Foodstuffs additives are a general term for materials that are added to the foodstuffs in order to increase durability and to improve the appearance, composition, taste and food nutritional value. Colors are classified in this group and are added to foodstuffs in order to increase their attraction. The aim of this survey was to analyze status of added colors to the juice of black cherry and juice of barberry which are produced in Tehran City, capital of Iran. Materials and Methods: Three haundred thirty six samples of dried sweets were randomly collected and analyzed from different areas of Tehran. First, the samples were de-colored by Clorhidric Acid, and then were analyzed after refining by Thin Layer Chromatography (T.L.C) method. Results: Eighty nine percent from the total samples contained colors. Among chromatic samples, 62 samples (18.5%) out the total samples, contained artificial, non-edible colors and 237 samples (70.5%) from the total samples contained artificial and edible colors (for Industrial Producers) and 37 samples (11%), contained natural colors. Carmoisine color was detected more than added colors in juice of black cherry and juice of barberry. Conclusion: Low costs, stability, Ph and similarity of artificial dyes with natural dyes motivate the producers for high utilization of these dyes without considering their possible hazards and/or their edible quality aspects.

Background and Aim: Foodstuffs additives are a general term for materials that are added to the foodstuffs in order to increase durability and to improve the appearance, composition, taste and food nutritional value. Colors are classified in this group and are added to foodstuffs in order to increase their attraction. The aim of this survey was to analyze status of added colors to the juice of black cherry and juice of barberry which are produced in Tehran City, capital of Iran.Materials and Methods: Three haundred thirty six samples of dried sweets were randomly collected and analyzed from different areas of Tehran. First, the samples were de-colored by Clorhidric Acid, and then were analyzed after refining by Thin Layer Chromatography (T.L.C) method.Results: Eighty nine percent from the total samples contained colors. Among chromatic samples, 62 samples (18.5%) out the total samples, contained artificial, non-edible colors and 237 samples (70.5%) from the total samples contained artificial and edible colors (for Industrial Producers) and 37 samples (11%), contained natural colors. Carmoisine color was detected more than added colors in juice of black cherry and juice of barberry.Conclusion: Low costs, stability, Ph and similarity of artificial dyes with natural dyes motivate the producers for high utilization of these dyes without considering their possible hazards and/or their edible quality aspects.

Background and Aim: Yersinia enterocolitica is a Gram-negative bacterium which its strains are involved in human diseases. To differentiate among pathogenic and non-pathogenic types, tests such as Congo Red absorption, Crystal Violet, and Calcium Dependency test are used. These tests are based on existence of 70-75 kb plasmids and sometimes, with respect to plasmids instability, we will face false negative results. Therefore, by setting up a methodology based on stable chromosomal genes of pathogenic agent we can overcome this hurdle. The goal of this survey was comparison among routine and molecular diagnostic approaches in the identification of Y. enterocolitica pathogenic strains.Materials and Methods: Some Gram-negative bacteria from family Enterobacteriacea and some Y. enterocolitica strains isolated of human beings and environment were evaluated.Results: Obtained results showed that 4 Y. enterocolitica strains isolated of human beings were PCR positive while PCR results of environmental strains, one human strain and non-Yersinia strains were negative.Conclusion: The mentioned approach can be used as a method to differentiate among pathogenic and non-pathogenic strains of Y. enterocolitica.

Background and Aim: Yersinia enterocolitica is a Gram-negative bacterium which its strains are involved in human diseases. To differentiate among pathogenic and non-pathogenic types, tests such as Congo Red absorption, Crystal Violet, and Calcium Dependency test are used. These tests are based on existence of 70-75 kb plasmids and sometimes, with respect to plasmids instability, we will face false negative results. Therefore, by setting up a methodology based on stable chromosomal genes of pathogenic agent we can overcome this hurdle. The goal of this survey was comparison among routine and molecular diagnostic approaches in the identification of Y. enterocolitica pathogenic strains. Materials and Methods: Some Gram-negative bacteria from family Enterobacteriacea and some Y. enterocolitica strains isolated of human beings and environment were evaluated. Results: Obtained results showed that 4 Y. enterocolitica strains isolated of human beings were PCR positive while PCR results of environmental strains, one human strain and non-Yersinia strains were negative. Conclusion: The mentioned approach can be used as a method to differentiate among pathogenic and non-pathogenic strains of Y. enterocolitica.

Introduction and objectives: Despite the advances in the control of food-borne diseases, still one of the dilemmas in the health of most societies and a matter of concern for health authorities is food poi­soning and food-borne diseases by unsafe foods. Materials and methods: In total 390 samples, including 195 samples of raw kebabs and hamburgers and 195 samples of the cooked ones were gathered from shops, sampling raw and cooked meat at the same time, and they were sent to the laboratory for testing, over a period of one year. The methods used for the tests were based on the Iranian National Standard procedures, numbers 356 and 2394. Results: All the cooked specimens had bacterial contamination in acceptable standard levels and there­fore were considered consumable. From the 165 raw kebab samples, 90 samples (54.5%) were con­sumable but 75 samples (45.5%) were not fit for consumption, where from 30 raw hamburger samples, 22 samples (73.3%) were consumable and 8 (26.7%) were inconsumable. In serological evaluations, Thompson serotype had the highest prevalence in kebab and hamburger samples. Conclusion: The results of present study show that there is no reason for concern in consuming cooked kebabs.

Introduction:Despite advances in disease prevention and food materials technology, food – borne diseases are still a major problem in both developed and developing countries. Morever, meat plays a key role in transfer of bacteria, especially “Zoonotic” to humans. Therefore, we decided to investigate the outbreak of pathogenic bacteria such as Salmonella,Campylobacter, Yersinia and Aeromonas in red meat and chicken offered as packed and unpacked in areas under the authority of Tehran university of medical sciences . Methods: 630 samples including 315 raw chicken meat and 315 raw red meat samples were collected and tested for a period of one year from July, 2004 to August,2005. Samples were collected from shops selling packed meat and chicken as well as shops selling unpacked meat and chicken in different parts of the south of Tehran The methods used for the laboratory investigation were based on Iranian National Standard Procedure No. 2394. Results: Of the 630 samples of chicken and meat, 183 samples (29 %) were contaminated. 49.2 percent of the contaminated samples were chicken meat and 8.9 percent were red meat. From the total, 71 samples were contaminated with salmonella (11.3 %), 68 samples with Campylobacter (10.8 %), 26 samples with Yersinia entrocolitica (4.1 %) and 18 samples with Aeromonas (2.9 %). In red meat samples, microbial contamination was observed in 4.9 % of packed and 10.3 percent of unpacked samples. Contamination rate of chicken samples was higher including 59.3 % of packed and 45.7 % of unpacked chicken samples. The observed difference between the remitting samples of packed and unpacked chicken was statistically significant. (P< 0.05) Conclusion: Our results indicated that although the centers selling packed and unpacked red meat from south of Teheran showed different microbial contamination rate, the differences were statistically insignificant. (P> 0.05)