The effect of thyme essential oil and endothelial progenitor stem cells on lipopolysaccharide-induced sepsis in C57BL/6 mice.

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.

Associations between climatic parameters and the human salmonellosis in Yazd province, Iran.

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.

Antimicrobial investigation on the multi-state outbreak of salmonellosis and shigellosis in Iran.

Background: Foodborne diseases are caused by indigestion of contaminated food. In some cases they may result in either hospitalization or death. The Centers for Disease Control (CDC) and Prevention in 2017 stated that 10% reduction in foodborne illness would prevent nearly five million illnesses every year. Approximately one out of six Americans become ill from contaminated foods or beverages every year. Another problem is drug resistance which is responsible for approximately 2 million illnesses and around 23000 dead every year. Nearly 400,000 Americans acquire antibiotic-resistant Salmonella or Campylobacter each year. The aim of this study was to evaluate the outbreak of salmonellosis and shigellosis along with their antibiotic susceptibility patterns in different provinces of Iran. Methods: Over a period of 2 years from 2015 to 2016, a total of 1055 cases in 249 outbreaks reported in 20 provinces of Iran, as a part of surveillance by the National Institute of Health (NIH). The stool samples of patients were taken and tested for Salmonella spp. and Shigella spp. by conventional standard techniques. Disk diffusion was used for the antibiotic sensitivity test. Results: Of 1055 cases, 118 (11.2%) contained Shigella and 74 (7%) contained Salmonella. Antibiotic susceptibility tests showed that entirely 100% of Salmonella and Shigella isolates were susceptible to ciprofloxacin; whereas 12.2% of Salmonella and 98.2% of Shigella were resistant to cotrimoxazole. Conclusion: Our results show that there is a need for more food handling practices to minimize the exposure of consumers to Salmonella and Shigella , at all points along the distribution chain.

Evaluation the cytotoxic effect of cytotoxin-producing Klebsiella oxytoca isolates on the HEp-2 cell line by MTT assay.

BACKGROUND: The cytotoxic effects on epithelial cells of the human are not observed in other strains of Klebsiella spp and are only observed in K. oxytoca strains. MTT assay was used to evaluate cytotoxic activity. In this study, colorimetric method was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. MATERIALS AND METHODS: In this study, we collected a total of 75 K. oxytoca strains isolate and we detected the production of toxins and their cytotoxic effects on HEp-2 cells. Colorimetric method such as MTT assay was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. RESULTS: Nine isolates had cytotoxic effects on HEp-2 cells. The results of MTT assay showed that the isolated strains were different from the control stain in terms of toxinogenicity and cytotoxic effects on HEp-2 cells at the studied dilutions (1:3, 1:6, 1:12, 1:24, 1:48, and 1:96). CONCLUSIONS: In the current study, Percentage of Hep-2 surviving cells exposed to 1:3, 1:6, 1:12, 1:24, 1:48, and 1:96 supernatant dilutions of cytotoxin-producing Klebsiella oxytoca isolates was different.

Identification of cytotoxin-producing Klebsiella oxytoca strains isolated from clinical samples with cell culture assays.

BACKGROUND: Klebsiella oxytoca is an opportunistic pathogen which damages intestinal epithelium through producing cytotoxin tilivalline. This toxin plays a role in the pathogenesis of bacteria and is the main virulence factor which leads to antibiotic-associated hemorrhagic colitis progress. MATERIALS AND METHODS: In this study, we collected a total of 75 K. oxytoca strains isolated from the stool, urine, blood, wounds, and sputum and evaluated them in terms of the production of toxins; we detected their cytotoxic effects on HEp-2 cells. RESULTS: Of all the isolates, five K. oxytoca strains isolated from the stool cultures, two strains isolated from the blood cultures, one strains isolated from the wound cultures, and one strains isolated from the urine cultures had cytotoxic effects on HEp-2 cells. The strains isolated from sputum cultures had no cytotoxic effects on HEp-2 cells. CONCLUSIONS: In the current study, the majority of strains isolated from the stool of the patients included cytopathic effects on HEp-2 cells.

Genetic diversity and virulence genes of Salmonella enterica subspecies enterica serotype Enteritidis isolated from meats and eggs.

Salmonella enterica subspecies enterica serotype Enteritidis (S. Enteritidis) is one of the leading causes of food-borne gastroenteritis associated with the consumption of contaminated food products of animal origin. Little is known about the genetic diversity and virulence content of S. Enteritidis isolated from poultry meats and eggs in Iran. A total of 34 S. Enteritidis strains were collected from different food sources of animal origin in Tehran from May 2015 to July 2016. All of the S. Enteritidis strains were serotyped, antimicrobial susceptibility tested, and characterized for virulence genes. Pulsed-field gel electrophoresis (PFGE) was also applied for comparison of genetic relatedness. All of the strains harbored invA, hilA, ssrA, sefA, spvC, and sipA genes. A high prevalence of resistance against certain antibiotics such as cefuroxime (79.4%), nalidixic acid (47%), and ciprofloxacin (44.2%) was also observed. Regarding PFGE, S. Enteritidis strains from different sources showed considerable overlap, suggesting the lack of diversity among these isolates. Moreover, no correlation between virulence profiles or antibiotypes and PFGE clusters was observed. In conclusion, our study provided valuable information on virulence gene content, antibiotic resistance, and genetic diversity of S. Enteritidis isolated from food sources.

Antibacterial activity of Lactobacillus spp. isolated from the feces of healthy infants against enteropathogenic bacteria.

Lactobacilli are normal microflora of the gastrointestinal (GI) tract and are a heterogeneous group of lactic acid bacteria (LAB). Lactobacillus strains with Probiotic activity may have health Benefits for human. This study investigates the probiotic potential of Lactobacillus strains obtained from the feces of healthy infants and also explores antibacterial activity of Lactobacillus strains with probiotic potential against enteropathogenic bacteria. Fecal samples were collected from 95 healthy infants younger than 18 months. Two hundred and ninety Lactobacillus strains were isolated and assessed for probiotic potential properties including ability to survive in gastrointestinal conditions (pH 2.0, 0.3% oxgall), adherence to HT-29 cells and antibiotic resistance. Six strains including Lactobacillus fermentum (4 strains), Lactobacillus paracasei and Lactobacillus plantarum showed good probiotic potential and inhibited the growth of enteropathogenic bacteria including ETEC H10407, Shigella flexneri ATCC 12022, Shigella sonnei ATCC 9290, Salmonella enteritidis H7 and Yersinia enterocolitica ATCC 23715. These Lactobacillus strains with probiotic potential may be useful for prevention or treatment of diarrhea, but further in vitro and in vivo studies on these strains are still required.

Surveillance for foodborne disease outbreaks in Iran, 2006-2011.

BACKGROUND: The outbreaks of foodborne diseases is a major health problem and occur daily in all countries, from the most to the least developed. This study is the first report of foodborne outbreaks in Iran that carried out from 2006 to 2011. METHODS: A retrospective, longitudinal study carried out using foodborne disease national surveillance system data from 2006-2011, which have been reported by all provincial health centers to the Center for Communicable Disease Control. Collected data were analyzed using SPSS version 18 software. RESULTS: Since 2006 to 2011, a total of 2250 outbreaks were reported in Iran. Analyzed data showed that the outbreak rate has increased from 0.07/100000 in 2006 to 1.38/100000 population in 2011. Khuzestan, Kermanshah and Qazvin were three provinces that reported more outbreaks than nationally expected outbreak incidence rate during 2011. Analysis of epidemiological characteristics of foodborne outbreaks during 2011 indicated that the numbers of outbreaks were highest in warm months, e.g. 17.8% of total outbreaks was just reported in August. Females and age group of 16-30 years old were more affected and 55% of cases occurred in rural area. Among 684 human samples which have been tested, E. coli, Shigella, Hepatitis A and Vibrio cholera were predominant etiologic agents respectively. CONCLUSION: Increasing the detection rate of foodborne outbreaks imply the expansion of surveillance activities and improved primary health care in Iran in recent years. Foodborne disease surveillance system is a new program in Iran that should be continued and strengthened including diagnostic laboratory capacities.

The effect of synbiotic coating of flaxseed mucilage-defatted rice bran carbohydrate on quality of dried mango, viability of Bifidobacterium animalis subsp. LactisBB12 on storage and simulating gastrointestinal condition.

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.

Biofilm formation, antimicrobial resistance genes, and genetic diversity of Salmonella enterica subspecies enterica serotype Enteritidis isolated from food and animal sources in Iran.

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 (blaTEM: 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.

Staphylococcus aureus Dormancy: Waiting for Insurgency.

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.

Evaluation of zinc oxide nanocomposite with Aloe vera gel for packaging of chicken fillet against Salmonella typhi and Salmonella para typhi A.

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-log10 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.

Antimicrobial resistance patterns, virulence gene profiles, and genetic diversity of Salmonella enterica serotype Enteritidis isolated from patients with gastroenteritis in various Iranian cities.

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.

NEBL and AKT1 maybe new targets to eliminate the colorectal cancer cells resistance to oncolytic effect of vesicular stomatitis virus M-protein.

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.

Molecular identification of aflatoxigenic Aspergillus species in dried nuts and grains collected from Tehran, Iran.

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 ß-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.

Antimicrobial Susceptibility, Serotyping, and Molecular Characterization of Antibiotic Resistance Genes in Listeria monocytogenes Isolated from Pregnant Women with a History of Abortion.

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 tetM, ermB and dfrD 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 tetM 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.

Oral administration of Lactobacillus acidophilus induces IL-12 production in spleen cell culture of BALB/c mice bearing transplanted breast tumour.

Lactic acid bacteria can affect the maturation of immune cells and their products not only in the gut but also on the systemic immune organs such as lymph nodes and spleen. In the present work, we studied the effects of oral administration of Lactobacillus acidophilus on the immune responses of BALB/c mice bearing transplanted breast tumour. Two groups of female inbred BALB/c mice, each containing nine mice as test and control, were used. The L. acidophilus ATCC4356 strain was inoculated in DeMan-Rogosa-Sharpe broth and cultivated for 24 h at 37 degrees C. Then, it was collected by centrifugation, and was washed and suspended in PBS. Afterwards, 0.5 ml/d of this suspension, which contained 2.7 x 108 colony forming units/ml of bacteria, was orally administered to the mice by gavage, 14 d before tumour transplantation and 30 d after that with 3-d intervals. Similar to the test mice, the control mice received an equal volume of PBS. The results showed that oral administration of L. acidophilus increased the production of IL-12 (P < 0.05) and decreased the level of transforming growth factor beta (P = 0.05) in the splenocyte culture. Moreover, the growth rate of tumour in the test mice decreased (P < 0.01), and the results of delayed-type hypersensitivity assay after 48 h were risen (P < 0.05) in comparison with the controls. Results suggest that daily consumption of L. acidophilus can improve the production of immunomodulatory cytokine IL-12 in the splenocyte culture, which was stimulated by tumour antigen in BALB/c mice bearing transplanted breast tumour. But further studies are needed to find out some other possible mechanisms of this effect.

Heterogeneity of Highly Susceptible Yersinia enterocolitica Isolates of Clinical and Environmental Origin: A 5-Year Survey from Iran (2011-2016).

The aim of this study was to evaluate the resistance and virulence characteristics of Yersinia enterocolitica strains of clinical and environmental origins over a 5-year period in Iran and to determine the genetic diversity of strains using pulsed-field gel electrophoresis (PFGE) method. A total of 20 Y. enterocolitica strains were collected from 850 stool samples of patients with diarrhea, and 18 Yersinia spp. including 10 Y. enterocolitica were collected from water, food, and vegetable samples. The most frequently isolated Y. enterocolitica strains belonged to biotype (BT) 1A (83.33%). No Y. enterocolitica BT4 was detected that can be attributed to the absence of pig animal reservoir in Iranian food chain. The most frequent chromosomal virulence genes among the Y. enterocolitica isolates were inv (100%), ystA (67%), ystB (83%), tccC (20%), and ail (17%). The most frequent chromosomal virulence genes among non-enterocolitica Yersinia spp. isolates were ystB (87.5%), ystA (37.5%), and inv (37.5%). None of the Y. enterocolitica isolates harbored plasmid origin virulence genes. None of the isolates was resistant to ciprofloxacin, gentamicin, tetracycline, cotrimoxazole, and chloramphenicol, whereas 90% of the Y. enterocolitica and 62.5% of the Yersinia spp. strains were resistant to ampicillin. PFGE genotyping showed a heterogeneous population of highly susceptible Yersinia spp. in both clinical and environmental samples, putting forward a good prognosis in the treatment of patients with yersiniosis. The occurrence of biotype 1A with inv+ystA+ystB+ genotype in clinical strains implies the significance of inv, ystA, and ystB gene products in turning of naturally nonpathogenic biotype 1A strains into clinically important pathogens.

Phytochemical Composition and Anti-Efflux Pump Activity of Hydroalcoholic, Aqueous, and Hexane Extracts of Artemisia tournefortiana in Ciprofloxacin-Resistant Strains of Salmonella enterica Serotype Enteritidis.

BACKGROUND: The AcrB efflux pump in Salmonella species plays a significant role in the development of antibiotic resistance in ciprofloxacin-resistant Salmonella enteritidis. This study aimed to investigate the anti-efflux pump activity of Artemisia tournefortiana extracts among S. Enteritidis strains. METHODS: The hydroalcoholic, aqueous, and hexanolic extracts of A. tournefortiana were prepared and phytochemical composition of extract was determined using gas chromatography/mass spectrometry (GC/MS) method. After antibiogram, the AcrB efflux pump was detected in ciprofloxacin intermediate and resistant S. enteritidis strains using cartwheel and Polymerase chain reaction (PCR) methods. Finally, minimum inhibitory concentrations (MIC) of extracts against S. enteritidis strains were evaluated. After treatment of S. enteritidis strains with sub-MIC concentrations of extracts, the expression level of AcrB efflux pump gene was evaluated using Real-Time PCR. RESULTS: Phytochemical analysis of extracts using GC/MS method showed that hexadecanoic acid, ethyl ester (30.7%), and cyclopropane,1-(1-hydroxy-1-heptyl)-2-methylene-3-pentyl (17.8%) were the most dominant volatile components volatile compounds in the extract. The results of antibiogram, cartwheel and PCR methods showed that among 20 strains of S. enteritidis that were resistant and intermediate to ciprofloxacin, 16 strains had AcrB efflux pumps. Finally, Real-Time PCR results showed a significant down-regulation of acrB gene in S. enteritidis strains. CONCLUSION: A. tournefortiana had anti-efflux activity and this plant can potentially be used as a natural efflux inhibitor for S. enteritidis strains.

Some probiotic properties of Lactobacillus species isolated from honey and their antimicrobial activity against foodborne pathogens.

Lactobacilli commonly used as a probiotic and they can be isolated from various sources such as fermented foods and gastrointestinal tracts of humans and animals. The aims of this study were isolation and identification of lactobacilli from honey and investigation of some probiotic properties and antimicrobial effects against foodborne bacterial pathogens. A total of 88 honey samples were collected from different areas in Iran. About 1.00 g of each honey was cultured in de Man, Rogosa, and Sharpe (MRS) broth and then sub-cultured on MRS agar. The isolates were assessed for probiotic potentials such as tolerance to acid and bile. Then, antimicrobial activity of isolates against seven foodborne pathogens including Listeria monocytogenes, Shigella flexneri, Staphylococcus aureus, Salmonella enteritidis, Enteropathogenic Escherichia coli, Escherichia coli O157 H7 and Bacillus cereus was investigated. From 88 honey samples, 39 isolates were identified by 16S rDNA gene sequencing method. Fructophilic lactic acid bacteria (FLAB) with 29 (74.00%) isolates were dominant identified bacteria (27 L. kunkeei and two Fructobacillus fructosus). Also, four L. plantarum, two L. paracasei, one L. brevis, one L. rhamnosus, one L. casei and one L. fermentum were identified. Two L. kunkeei isolates and one F. fructosus isolate were resistant to acid and bile salt. Two L. rhamnosus isolates and one L. paracasei isolate inhibited all pathogens (100%). This is the first study in Iran that isolated lactobacilli from honey. The FLAB especially L. kunkeei were isolated as dominated species from honey. Some lactobacilli isolates have probiotic potential and may be useful for the prevention and treatment of infections, but more investigations are needed.