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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.

Abstract Background and Objective: This study aimed to investigate the antimicrobial susceptibility of the most common pathogens in hospitalized neonates in Intensive Care Unit. Material and Methods: In this one-year descriptive study, 150 blood samples of neonates in Intensive Care Unit of Bahrami hospital of Tehran were divided into two groups of early onset sepsis (the first 72 hours of life) and late onset sepsis (after the 72 hours of life). After isolating and identifying of bacteria, their antibiotics susceptibility was studied by Kirby- bauer method in accordance with CLSI guidelines. Result: The most isolated organisms were Klebsiella pneumoniae (41.3%). Coagulase negative staphylococcus was the cause of early onset septicemia and Klebsiella pneumoniae of both early and late onset septicemia. The highest susceptibility in gram-negative microorganisms was shown to Ciprofloxacin (89.6%) and in gram positive to Vancomycin (82.8%). Conclusion: Gram-negative bacteria are the main cause of contamination in NICU and ciprofloxacin is the most effective antibiotic. Thus, it is imperative that NICU should be extremely controlled. Keywords: Septicemia; Antibiotic Susceptibility; Neonatal Intensive Care Unit

Background: Staphylococcus aureuse is one of the important pathogens which transmitted by food and has majority of habitant in human and animal community as a pathogen and normal flora. Antibiotic resistant among Staphylococcus aureuse strains is a global health challenge. Objective: Regarding to the different therapeutic and antimicrobial effect of Shirazi Zataria multiflora and Rosemarinus officonalis in present work the antibacterial effect of this extract and its synergistic effect with routine antibiotics was investigated. Methods: In this in vitro study the antimicrobial effect of Shirazi Zataria multiflora and Rosemarinus officonalis extract on methicillin resistant Staphylococcus aureus (MRSA) and other antibiotic resistant strains to tetracycline, erithromycine, trimethoprim, sulfamethoxazol, together with its MIC and MBC were determined. Also synergistic effect of these extracts with these antibiotics was investigated by paper disc method. Results: Shirazi zataria multiflora, had a significant antibacterial effect against MRSA, and other Staphylococcus aureus resistant strain to tetracycline, erithromycine, trimethoprim, and sulfametoxazol, isolated from food. Conclusion: Production of a suitable herbal medicine with few side effects will give rise to a promising outlook in the treatment of infections caused by antibiotic resistant strains of Staphylococcus aureus.

Abstract Background and Objectives: gasterointertidis is one of the most common forms of Salmonellosis, which is a worldwide problem. The invasive characteristic of intestinal bacteria is one of their pathogenicity Mechanisms , which can be easily investigated by cell culture technique. In this study ,the invasive characteristic of some Salmonella serogroup were investigated by using HEP-2 cell. Methods and Material: The rectals soap were prepared from 280 diarrhea patients referred to Imam Khomeyni and children medical centres , 140 with bloody diarrhea and 140 with watery diarrhea as a comparison group. The rectal soap was taken before patients taking any antibiotics, and 140 rectal specimens were taken from healthy people as a control group. All the samples were inoculated in differential and selective media, like Hektoen enteric agar and Xylose lysine deoxycholate (XLD) agar .After incubation at 37C for 24 hours, the colonies were examined and identified by conventional biochemical and serological tests. Using HEP-2, cellular invasion characteristic of Salmonella serogroups was assessed. Moreover, the antibiotic resistance patterns were performed according to Clinical and Laboratory Standards Institute (CLSI). Results: Of all tested samples, 35(8.3%) are Salmonella strains. The frequency of Salmonella is reported for bloody diarrhea (5.2%) , watery diarrhea ( 1.7%) and control group( 1.4%) .The most abundant serogroups with invasive characteristic, using HEP-2 cell culture, are serogroup B ( 62.9%) and D (17.2%). Conclusion The results obtained in this study show that the majority of Salmonella isolates are without invasive characteristic. Key words: Salmonella, Diarrhea, Cell invasion, Cell culture

Background: Group B streptococcus (GBS) is one of the most important cause of morbidity and mortality among newborns especially in developing countries. It has been shown that the screening approach rather than the identification of maternal clinical risk factors for early-onset neonatal GBS disease is more effective in preventing early-onset GBS neonatal disease. The objective of this study was to detect GBS among clinical samples of women using PCR and standard microbiological culture.Methods: Samples were taken from 375 women at 28-38 weeks of gestation during six month from January 15 till June 15, 2011 from a hospital in Tehran, Iran. Samples were tested by standard culture using Todd-Hewitt broth, blood agar and by PCR targeting the cfb gene.Results: Among the 375 women, 35 (9.3%) were identified as carriers of group B streptococci on the basis of the results of the cultures of specimens, compared to 42 (11.2 %) on the basis of PCR assay.Conclusion: We found that GBS can be detected rapidly and reliably by a PCR assay in vaginal secretions from women at the time of delivery. This study also showed that the rate of incidence of GBS is high in Iranian women.

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: Enterococci are members of the normal gut flora and released into the environment via sewage outlets, where they can survive for long times. Infections with high-level gentamicin resistant (HLGR) enterococci are emerg­ing worldwide. HLGR enterococci have developed a resistance to most antibiotics commonly used for enterococcal in­fec­tions therefore; treatment of infections caused by HLGR enterococci is difficult. The present study investigated the dis­tribution and antibiotic resistance of HLGR Enterococcus faecium and E. faecalis isolates from raw wastewater sam­ples in Tehran.Methods: Raw wastewater samples were collected during the period from November 2006 to May 2007 at 3 sewage treat­ment plants located in different parts of Tehran. All 90 HLGR enterococcal isolates were identified to the species level by biochemical and PCR assays and subjected to antibiotic susceptibility testing. Results: Sixty four percent (58 of 90) of isolates were E. faecium and 29%(26 of 90) of them were E. faecalis. The high­est level of antibiotic resistance was observed with erythromycin (63%), co-trimoxazole (69%) and tetracycline (92%) for E.faecalis and with erythromycin (97%), ciprofloxacin (47%), co-trimoxazole (45.5%) and tetracycline (47%) for E. faecium. Multiresistance against 3 to 4 antimicrobial was present in 27.5% and 15.5% of the isolates, re­spectively. Conclusion: HLGR E. faecium were more commonly found than E. faecalis. Species identification of HLGR entero­cocci enables us to assess species-specific antibiotic susceptibility patterns in our area. The present study reviled that HLGR E. faecalis remained more susceptible than E. faecium against the usual first-line and alternative treatments.

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)

In recent years, the importance of Shigella as an enteric pathogen with global impact has been increasingly recognized. In this study, serogroup distribution of Shigella isolated from clinically diagnosed cases of gastroenteritis and acute diarrhea in Tehran, capital of Iran was investigated between December 2002 and November 2003. Fecal specimens and rectal swabs were cultured for Shigella spp. using standard microbiological techniques. The isolates of Shigella were identified by biochemical assay and serological testing. From a total of 302 Shigella isolates, 178, 110, 10 and 4 strains were identified as S.sonnei (58.9%; 95% CI: 53.2-64.5), S. flexneri (36.4%; 95% CI: 31.0-42.2), S.boydii (3.3%), and S. dysenteriae (1.3%), respectively. The peak of infection occurred during summer. Overall, 167 patients (55.3%) were males and 135 (44.7%) were females

According to changes in the surface of respiratory epithelial cells and host immunity as well as virulence of hospital acquired pathogens, oropharyngeal colonization enhance in hospital admitted patients. Patient admission in hospital, due to changes of oropharyngeal flora and colonization of virulent germs such as Staphylococcus aureus and gram negative bacilli can be a serious problem for developing respiratory infections and nosocomial septicemia. This investigation was carried out on effects of residency of patients in the hospital by oropharyngeal flora. This was a Quasi-clinical trial and assembled data is based on observation and interview. Oropharyngeal germ samples of 30 admitted patients in dermatology ward of Loghman hospital were cultivated at the first and fifth day of admission. All the colonies were distinguished by microbiologists. Thirty patients at the range of 44± 20 years of age were studied. There have been history of corticosteroid usage in 16 persons (53%) and usage of a cytotoxic drug in 8 persons (27%).There has been α– hemolytic Streptococci in 100% of patients, Neisseria in 87% , coagulase positive Staphylococci in 3%, yeast in 3% and gram negative bacilli in 13% of the patients at the beginning of admission. At the fifth day of admission, α - hemolytic Streptococci & Neisseria had the same values as they were at the first, but colonization of coagulase positive Staphylococci increased by 30% , the increase of the yeast was 23%. According to this study changes of oropharyngeal flora in a 5 days admission were statistically significant for coagulase positive Staphylococci and yeast but these changes are not significant for other investigated germs.

Background: Group B streptococcus (GBS) is one of the most important cause of morbidity and mortality among newborns especially in developing countries. It has been shown that the screening approach rather than the identification of maternal clinical risk factors for early-onset neonatal GBS disease is more effective in preventing early-onset GBS neonatal disease. The objective of this study was to detect GBS among clinical samples of women using PCR and standard microbiological culture. Methods: Samples were taken from 375 women at 28-38 weeks of gestation during six month from January 15 till June 15, 2011 from a hospital in Tehran, Iran. Samples were tested by standard culture using Todd-Hewitt broth, blood agar and by PCR targeting the cfb gene. Results: Among the 375 women, 35 (9.3%) were identified as carriers of group B streptococci on the basis of the results of the cultures of specimens, compared to 42 (11.2 %) on the basis of PCR assay. Conclusion: We found that GBS can be detected rapidly and reliably by a PCR assay in vaginal secretions from women at the time of delivery. This study also showed that the rate of incidence of GBS is high in Iranian women.

Abstract Background and objectives: Water-born diseases are typically caused by pathogens transmitted by orofecal way. Because it is no practical and no economical and also it is time-consuming to find water-born pathogens in water reservoirs, the laboratory studies are performed on the basis of indicator microorganism. Escherichia coli is considered as the most important indicator bacterium for water monitoring. The aim of this study was to evaluate the three methods of Pour Plate (PP), Most Probable Number (MPN) and Membrane Filter (MF) in isolation of Escherichia coli in well water of Parks. Material and Methods: One hundred and sixty five samples of well water, from five geographical zones of north, south, east, west and center of Tehran, were taken in a sterile condition and sent to microbiology department of health faculty to assess with three methods of PP, MPN and MF. The results were analyzed by chi-square. Results: The results indicate that 90 water samples (54.5%) aren’t health. The samples taken from south of Tehran are most contaminant than other zones. The highest contaminated Samples (54.5%) are related to membrane filtration method in comparison with MPN (34.5%) and PP (27.3%). Conclusion: Since the MF method can recognize the contaminants quickly and effectively, we recommend it more. Based on these results, it is essential to educate children not to drink well water in parks. Keywords: well water contamination, Escherichia coli, Tehranchr('39')s parks

Background: To assess the utility of the chromosomal ail virulence gene sequence for detection of pathogenic Yersinia en­terocolitica in raw meet food products (beef, lamb, and chicken). Methods: This study included 39 Yersinia enterocolitica positive cultures from suspicious food samples, in a working pe­riod of six months. These samples were referred to the "Food-Borne Diseases and Chronic Diarrhea Lab at Research Cen­tre for Gastric and Liver Diseases" of the Taleghani Hospital at Shahid Beheshti University of Medical Sciences, Te­hran, Iran. Isolates from 8 cultured Y. intermedia, Y. aldovi, Y. intermedia type O:45, Y. kristensenii, Y. enterocolitica type O:12/26, Y. enterocolitica type1/7/8, Y. frederiksenii type O:39, and Y. enterocolitica type O:8 samples were in­cluded in the study. Four non-Yersinia species Salmonella typhi, Shigella dysenteriae, Shigella flexeneri, and Proteus mirabi­lis were used for specificity testing. An established Yersinia type O:9 was used as positive control and for sensitiv­ity testing. An in-house real-time PCR assay was designed in order to rapidly and specifically identifies the pres­ence of specific Yersinia species. Results: Out of 39 tested Y. enterocolitica samples, 6(2.3%) showed positive results for the ail gene PCR prod­uct, typed as O:8, and O:9, respectively. PCR products were sent for sequencing. Two sequences were registered with the Na­tional Center for Biotechnology Information (NCBI Genbank) as polymorphic ail gene sequences under the acces­sion numbers of DQ157767 and DQ003329. Conclusions: Collectively, this test is well adapted for definite confirmation of pathogenic Y. en­terocolitica in food sam­ples.

Salmonella is the main bacterial pathogen that causes foodborne disease, particularly in developing countries. Nontyphoidal Salmonella (NTS) include Enteritidis and Typhimurium as the most prevalent strains which are one of the significant causes of acute gastroenteritis in children. Therefore, identifying the most predominant serovars, types of common contaminated food, and paying attention to their antibiotic resistance are the main factors in the prevention and control strategy of salmonellosis. This study was undertaken to evaluate the prevalence rate of serovars, the biofilm formation, antimicrobial resistance (AMR) status, and phenotypic virulence factors of Salmonella strains isolated from diarrhea samples in some cities of Iran. A total of 40 (10.41%) Salmonella isolates were recovered from 384 diarrhea samples processed and the most common serovar was Salmonella serovar Typhimurium (82.5). Also, all isolates belonging to serovar Typhimurium showed more virulence factors compared to other serovars. The isolates showed a high resistance rate to ampicillin (95%) and nalidixic acid (87.5%), while a low resistance rate was found for chloramphenicol (2.5%). Moreover, significant variances in the capacity of biofilm formation were found between different Salmonella serotypes. The resistance of NTS to extant choice drugs is a potential public health problem. Constant monitoring of AMR pattern and virulence profile of NTS serovars is suggested for the prevention of salmonellosis in humans., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Mohammad Mehdi Soltan Dallal et al.)

Sepsis is a potentially fatal syndrome related to severe systemic inflammation developed by infection. Despite different antimicrobial therapies, morbidity and mortality rates remain high. Herbs along with cell therapy have been introduced as a promising option to improve the symptoms of sepsis. The present study aimed to evaluate the therapeutic effect of simultaneous administration of thyme essential oil (TEO) and endothelial progenitor stem cells (EPCs) on lipopolysaccharide (LPS)-induced sepsis in C57BL/6 mice. Sepsis was induced in C57Bl/6J mice by intraperitoneal injection of LPS, followed 2 h later by an intravenous injection of EPCs or oral administration of TEO or simultaneous administration of TEO and EPCs. After 10 days, the complete blood cell, renal and liver factors, serum levels of inflammatory cytokines, and angiogenic factors were measured. Simultaneous treatment with EPCs and TEO significantly increased the survival of mice with sepsis and modulated the inflammatory response by reducing the serum levels of pro-inflammatory cytokines. Moreover, this treatment significantly reduced the level of white blood cells and neutrophils and increased the number of red blood cells, the percentage of hematocrit, and hemoglobin. The combination of TEO with EPCs decreased organ injuries and was assessed by lower levels of the liver enzymes alanine aminotransferase and aspartate aminotransferase compared to the sepsis group. Administration of EPCs and TEO also significantly improved angiogenic factors, lung function, and toll-like receptor 4 expression. EPCs in combination with TEO increase survival in the LPS-induced sepsis mice model by acting on several targets. Thus, the combination of TEO with EPCs can be a feasible approach for the future clinical treatment and control of sepsis., (© 2024 International Union of Biochemistry and Molecular Biology, Inc.)

In the present study, a synbiotic coating of flaxseed mucilage, defatted rice bran carbohydrate, and Bifidobacterium animalis subsp. Lactis BB12 was fabricated for coating dried mango slices (M-P-C). The control samples contained only probiotic bacteria without coating (M-P). Several quality parameters (moisture, weight loss, shrinkage percentage, pH, firmness, and color) were assessed on specific storage circumstances (25°C, relative humidity (RH) = 22%.). In addition, the survival of Bifidobacterium animalis subsp. Lactis BB12 was evaluated on storage and under simulated gastrointestinal (GI) conditions. According to the results, the log number of Bifidobacterium animalis subsp. Lactis BB12 reached 8.1 and 6.2 for coated and uncoated samples, respectively, during the 45 days storage at 25°C (>6 log CFU (log colony-forming units)/g) and at finished stage of in vitro gastrointestinal circumstances, the log number of probiotic bacterial count reached 6.8 and 4 for coated and uncoated samples, respectively. The coating resulted in significantly less weight loss, moisture loss, and shrinkage of the mango slices than uncoated ones ( p  < .05). The growth of yeasts and molds was undetectable in both samples. The results of acceptance experiments for M-P and M-P-C dried mango samples showedthat there were no significant differences between M-P and M-P-C samples ( p   >.05), indeed in the case of purchase intention and overall acceptability. After reading the text highlighting, there was no significant difference in all attributes of M-P-C samples pre and post of reading text highlighting. It could be concluded that the synbiotic coating of mango slices improved the quality characteristics of the dried mango as well as viability of the probiotic bacteria at storage time and under simulated gastrointestinal conditions., (© 2024 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Objectives: Salmonella enterica serovar Entritidis is an important pathogen in foodborne diseases and causes gastroenteritis. Several studies have investigated the genetic diversity of the strains of this bacterium. However, our knowledge of the discriminatory power of the molecular methods is limited., Methods: In total, 34 strains of S. enteritidis were isolated from food related to animals. Antibiotic resistance of the strains, antibiotic resistance genes, and biofilm formation capacity of the strains were evaluated. For the genetic analysis of the strains, PFGE was performed using AvrII restriction enzyme., Results: Among the tested antibiotics, cefuroxime, nalidixic acid, and ciprofloxacin showed the highest resistance rates (79.4%, 47%, and 44.2%, respectively). Only three antibiotic-resistance genes were identified in these strains (bla TEM : 67.6%, tetA: 9%, and sul2: 3%). In total, 91% of the strains were biofilm producers. Clustering of strains using AvrII for 26 samples with the same XbaI PFGE profile showed that these strains were in one clone and had high homogeneity., Conclusions: In conclusion, it is better to use a combination of several typing methods for typing strains that are genetically very close so that the results are reliable., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The growing demand for high food quality has been encouraging researchers in the food industry to apply biodegradable nanocomposites, which provide new opportunities and challenges for the advance of nanomaterials in the food industry. The objective of this study was to estimate the antibacterial activity and cytotoxicity effects of zinc oxide nanocomposite/zeolite (c/Zeo) with Aloe vera gel (AG) and its effect on the shelf life of chicken meat. The ZnONPs/Zeo was assessed using X-ray fluorescence (XRF) and field emission scanning electron microscopy (FE-SEM) analyses. The cytotoxicity effect of ZnONPs/Zeo was assessed by MTT assay. Then, the minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) of ZnONPs/Zeo and ZnONPs/Zeo-AG against Salmonella typhi and Salmonella para typhi A were investigated. Also, the preservative effect of nanocomposites on chicken fillets was evaluated. The results showed that these nanocomposites have the least cytotoxicity effect, resulting in good biocompatibility with the host. The MIC and MBC values of ZnONPs/Zeo-AG were lower than the ZnONPs/Zeo against S. typhi and S. paratyphi A. Both ZnONPs/Zeo-AG and ZnONPs/Zeo caused a significant decrease in the bacterial count of the chicken fillets. So, by spraying on meat, the number of bacteria presented a sharper decline as compared with the control group, resulting in an approximately 3.3 and 3-log 10 reduction over 48 h in the ZnONPs/Zeo-AG and ZnONPs/Zeo treatment samples, respectively. In conclusion, antimicrobial packaging with ZnONPs containing A. vera is a beneficial solution for preserving and improving the quality, safety, and shelf life of fresh meat products., Competing Interests: No competing interests to declare., (© 2023 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Relapse infection usually results from resistance to the antibiotic, acquired genes, or persister cells. Persister cells are formed through mutation, reduced activity or metabolically inactive pathways induced by antibiotics, harassing conditions, low ATP, and malnutrition. These factors provide the ground for bacteria to grow slowly. Such a slow growth rate makes traditional antibiotics ineffective against persister cells. Staphylococcus aureus (S. aureus) , in addition to this form, can be observed in Small Colony Variants (SCVs), L-forms, and dormant, all of which are characterized by at least one feature, i.e. , slow growth. Despite their slow growth, they are metabolically active in terms of stringent SOS and cell wall stress responses. The stress response involves resistance against harassing conditions, and it survives until it is reactivated later. The present study aims to discuss the mechanisms of all persister cell formations, circumstances involved, gene mutation, and adoptable strategies against it., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

This study compares the oncolytic effect of vesicular stomatitis virus (VSV) wild type and M51R M-protein on the colorectal tumors of different invasive intensity on SW480 and HCT116 cell lines and 114 fresh colorectal cancer primary cell cultures. Fresh tumor samples were divided into two groups of lower stages (I/II) and higher stages (III/IV) regarding the medical records. The presence of two mutations in the PIK3CA gene and the expression of NEBL and AKT1 genes were evaluated. The cells were transfected with a plasmid encoding VSV wild-type and M51R mutant M-protein. Results showed either wild type or M51R mutant can kill SW480 and stage I/II primary cultures while mutant M-protein had no apoptotic effects on HCT116 cells and stage III/IV primary cultures. NEBL and AKT1 expression were significantly higher in resistant cells. Elevated caspase-9 activity confirmed that the intrinsic apoptosis pathway is the reason for cell death in lower-stage cells. Different tumors from the same cancer exhibit different treatment sensitivity due to genetic difference. NEBL and AKT1 gene expression may be responsible for this difference, which may be the target of future investigations. Therefore, tumor staging should be considered in oncolytic viral treatment as an interfering factor., Competing Interests: The authors declare that they have no conflict of interest., (© 2021.)

Introduction: Agricultural commodities contaminated by molds and mycotoxins can be considered as public health problems in less developed countries, particularly in Iran. Hence the main purpose of this study was to identify mold fungi and molecular analysis of the most important species of aflatoxin-B1-producing Aspergillus species in some dried nuts and grains in local markets in Tehran., Materials and Methods: Two hundred fifty samples of wheat, rice, corn, pistachios, and peanuts were collected from the five different locations of Tehran between January 2018 and January 2019. The samples were analyzed by using direct seed inoculation method and grain crushing method. Fungal strains were identified as Aspergillus spp. on the basis of morphological characters and further confirmed by using of β-tubulin gene sequencing. To differentiate between aflatoxigenic and non-aflatoxigenic Aspergillus spp., the isolates were screened for the presence of aflatoxigenic genes ( nor-1 , ver-1 , omtA , and aflR )., Results: One-handed forty-eight aflatoxigenic Aspergillus isolates (144 A. flavus and 4 A. parasiticus ) were identified and aflR gene was the most frequent gene in these species. Five isolates (4 A. flavus , 1 A. parasiticus ) had quadruplet pattern, 64 isolates (63 A. flavus , 1 A. parasiticus ) had more than 1 gene and 39 isolates (38 A. flavus ,1 A. parasiticus ) did not have any genes., Conclusion: According to the contamination of dried nuts and grains by some aflatoxigenic fungi, an extensive surveillance is necessary to provide a wider view on these products. Moreover, effective and efficient aflatoxin control program requires identifying and managing key elements that are effective in reducing mycotoxin production at farm level or in storage conditions., Competing Interests: Conflict of interestThere is no conflict of interest between authors in this study., (© Springer Nature Switzerland AG 2021, corrected publication 2021.)

Objectives: This study aimed to evaluate antibiotic resistance profiles and presence of virulence genes among Salmonella enterica serovar Enteritidis ( S. Enteritidis) isolated from patients with gastroenteritis in various regions of Iran. Moreover, genetic relatedness among the strains was assessed by pulsed-field gel electrophoresis (PFGE)., Materials and Methods: From April through September 2017, 59 Salmonella strains were isolated from 2116 stool samples. Of these strains, 27 S. Enteritidis were recovered. These strains were subjected to disk diffusion tests, polymerase chain reaction (PCR) for detection of virulence genes ( invA, hilA, pefA, rck, stn, ssrA, ssaR, sefA, spvC, sipA, sipC, sopB, sopE , and sopE2 ), and PFGE., Results: High prevalence of resistance towards cefuroxime (n = 20, 74.1%) and ciprofloxacin (n = 13, 48.2%) were demonstrated. All tested strains possessed invA, hilA, sefA, sipA, sopB , and sopE . The least prevalent virulence gene was rck (n = 6; 22.2%). Based on combinations of virulence genes, 12 virulotypes were observed. The most common virulotype was VP2 (n = 12; 44.4%), harboring all of the virulence genes except for rck . PFGE typing showed only two distinct fingerprints among tested strains. Each fingerprint had completely different virulotypes. Notably, VP4 (harboring all genes except for rck and spvC ) was only presented in pulsotype A, while VP2 was confined to pulsotype B., Conclusion: S . Enteritidis strains were derived from a limited number of clones, suggesting that it is highly homogenous. Future works should consider combinations of other genotyping methods together with larger sample sizes from more diverse sources., Competing Interests: The authors declare that they have no conflicts of interest.

Background: Listeria monocytogenes show high mortality among pregnant women and newborns. This study aimed to detect L. monocytogenes in pregnant women with a history of abortion and assess the serotypes, antibiotic susceptibility patterns, and its resistance genes., Methods: Overall, 400 vaginal swabs were taken from pregnant women with a history of abortion in the past few years in a tertiary care hospital in Tehran, Iran, during 2015-2018. Antibiotics susceptibility to a panel of 10 antibiotics was determined using the standard disk diffusion method and the isolates serotyped by the agglutination method. The antimicrobial-resistant isolates were also screened for the presence of tet M, erm B and dfr D genes by PCR., Results: Overall, 22 L. monocytogenes isolates were identified. High rates of resistance were observed for trimethoprim (50%; n=11), sulphamethoxazole (50%; n=11), tetracycline (45.45%; n=10) and gentamicin (36.36%; n=8). From 22 L. monocytogenes isolates, 13 (59.10 %), 5 (22.73%), 3 (13.63%) and 1 (4.54%) belonged to serotypes 4b, 1/2a, 1/2b, and 3c, respectively. The genetic determinant tet M was detected in 70% of the tetracycline-resistant isolates. Out of 11 trimethoprim-resistant isolates, 27.27% isolates contained dfrD . Moreover, the ermB gene was found in 83.33% of the erythromycin-resistant isolates., Conclusion: Ampicillin and partly penicillin consider to be suitable antimicrobial agents to treat human listeriosis. Moreover, due to resistance against many antibiotics, it is necessary to continue monitoring and managing antimicrobial resistance., Competing Interests: Conflict of interest The authors declare that there is no conflict of interests., (Copyright © 2021 Heidarzadeh et al. Published by Tehran University of Medical Sciences.)

Salmonella is one of the most common causes of foodborne disease outbreaks in developing countries. Climatic factors such as temperature, rainfall, and relative humidity can directly increase the growth and spread of these pathogens. Therefore, the aim of this study was to investigate long-term temporal trends and seasonal patterns of Salmonella infections as well as evaluating the effects of demographic and climatic factors on the infection incidence in Yazd province, Iran during 2012-2015. The incidence of Salmonella infections was highest among patients with the age group of ≤5 years and peaked in summer, especially during June. Contrary to expectations, no significant associations were seen between the average monthly temperature, rainfall or humidity and incidence rate (IR) of salmonellosis. Interestingly, atmospheric dust hovering was significantly associated with an increased risk of salmonellosis. Transmission pathways of Salmonella spp. in communities should be considered as a complex ecological process that animal reservoirs, socio-economic factors, and lifestyle behaviors need to be addressed in future studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Inc.)