فهرست مطالب mohammadkazem sharifi yazdi

Yersinia is water and foodborne organism that cause human gastroenteritis. This study was done to evaluate the frequency of Yersinia species isolated from children diarrheal samples and chicken meat in Tehran, Iran.

In this descriptive study 250 sample of diarrhea of children referred to the Children's Medical Center, Tehran, Iran and 250 samples of chicken were collected and examined for Yersinia infection during July 2016 to March 2017. Isolation method was performed based on initial enrichment in phosphate buffer for 3 weeks in refrigerator (cooling in c4 +) and then using KOH as secondary enrichment and culture on CIN agar medium. Biotyping method was used to determine pathogenic strains.

In this study, 5(2%) isolates from pediatric diarrhea samples and 20 isolates (8%) from chicken meat samples were obtained from Yersiniaenterocolitica. Biotyping of human Yersiniaenterocolitica isolates identified 3 cases of biotype 1A, one case of biotype 1B, one case of biotype 2 and from chicken meat isolates, 16 isolates belonged to biotype 1A and 4 isolates belonged to biotype 1B.

Presence of common pathogenic 1B and non-pathogenic 1A biotypes in pediatric diarrhea samples and chicken meat can indicate the cause of diarrhea in children.

Resistance to a wide range of beta-lactam family antibiotics is due to the emergence of new beta-lactamases among bacterial strains. The aim of the present study was to determine the prevalence of ESBLs in Klebsiella speices isolated from raw and pasteurized school
milk using phenotypic and genotypic methods. 

In a descriptive cross-sectional study, 200 samples of raw and pasteurized school milk were analyzed for the presence of Klebsiella spp. Samples were grown on Hektoen enteric agar medium. Suspected colonies of Klebsiella spp. were confirmed running differential tests. For the initial screening of ESBL producing organisms, the Disk Diffusion Agar method (DDA) was used. Final confirmation was done using PCR.

Out of 200 samples tested, 44 isolates were identified as Klebsiella, 32 isolates (72.7%) from raw and 12 (27.3%) from pasteurized school milk. In general, 14 (31.8%) isolates that were resistant to at least ceftazidime or cefotaxime antibiotics were selected for confirmatory testing.In Multiplex PCR assay, 6 (3%) isolates were screened for the confirmatory test (5 raw and 1 pasteurized school milk). Out of 6 isolates, 4 (2%) and 1 (0.5%) isolates contained TEM and DHA genes, and 2 (1%) and 1 (0.5%) isolates contained SHV and CITM genes, respectively.

It is difficult to identify the enzymes producing strains through the phenotypic tests; therefore, the inclusion of molecular probes using universal primers along with phenotypic tests can be used for the detection of these types of resistance, which play a major role in infection control.

 Phage therapy could be used as an alternative method to antibiotic treatments. The purpose of this study was to evaluate the antibacterial activities of isolated lytic bacteriophage against ciprofloxacin-resistant strain of Salmonella infanits in vitro conditions.

 The standard strain of Salmonella infantis  and its specific bacteriophage was isolated by soft agar method. Phage susceptibility to heat and pH was evaluated by the Double-Layer Agar method.  In vitro assay was carried out on human epithelial type 2 (HEp-2) cells to investigate the effect of bacteriophage on the cytotoxic and invasion of Salmonella infantis to human epithelial cells.

 Head and tail morphology of bacteriophages against Salmonella infantis were identified by transmission electron microscopy and assigned to the Myoviridae family. The results of the double-layer agar assay showed that the titer of bacteriophages was 1.8×107 PFU/ml. bacteriophage was stable at 4 C and the best quantification of bacteriophage was determined at pH=8. The isolated bacteriophage was specific for Salmonella infantis and had no lytic activity against other pathogenic bacteria. In the evaluation of the binding and invasion of Salmonella infantis to the HEp-2 cell line, as expected, the lytic activity of specific bacteriophage was observed following inoculation.

 Additional studies are needed for better understanding of the interaction between phage, microorganisms and human host before applying phage therapy on a large scale.

Campylobacter is one of the most important pathogens causing bacterial gastroenteritis, which is usually transmitted through the food of animal origin. This study was done to evaluate the status of Campylobacter in diarrheal food outbreaks compared to other microbial agents.

This descriptive study was performed on 305 diarrheal swab samples from 102 food outbreaks during six months from spring to the end of summer 2018. Presence of Campylobacter species were assessed according to the protocol of the General Directorate of Laboratory Affairs.

Out of 305 samples, 8 (2.6%) were identified as Campylobacter species, 3 (37.5%) Campylobacter and 5 (62.5%) Campylobacter coli. The epidemiology of the outbreaks showed that female (54.5%), average age of 16-30 years (28.2%), consumption of salads and vegetables (16.1%) and living in the cities (59.7%) were the most cases.

This study showed that in addition to classic pathogens such as Salmonella, Shigella, Escherichia coli, attention also should be paid to Campylobacter bacteria. In addition, recognizing epidemiological factors can play an important role in preventing and controlling food outbreaks.

The most common enterohemorrhagic Escherichia coli strain is the O157: H7 serotype, which is one of the most important intestinal pathogens and can cause complications such as hemorrhagic colitis, hemolytic uremic syndrome and acute renal failure. The aim of this study was to evaluate the enterohemorrhagic Escherichia coli causing molecular outbreaks of foodborne illness in Iran.

In this descriptive cross-sectional study, 189 fecal swab specimens were examined during April to September 2018. All suspected isolates were tested for biochemical tests. The isolates were confirmed by molecular PCR and evaluated by antimicrobial susceptibility tests.

From 189 stool swab samples studied, 98 Escherichia coli isolates were detected based on phenotypic tests. Most of the outbreaks occurred in summer and the prevalence of enterohemorrhagic Escherichia coli was 24.5%, which 4% of them were non-O157H7. Most patients were between 1 and 12 years of age and the highest antibiotic resistance to cotrimoxazole and chloramphenicol was observed at 80% and 79%, respectively.

This study showed an increase in enterohemorrhagic Escherichia coli with 24.5% and an increase in antibiotic resistance to the antibiotics of chloramphenicol, cotrimoxazole and carbapenems. Increased resistance to imipenem and meropenem antibiotics makes it difficult to treat beta-lactamase-resistant strains.

Foodborne diseases are a major problem worldwide. The epidemiological investigations in many parts of the world have shown an increase in infections caused by Salmonella serovars. Furthermore, the emergence of drug resistance among them has become a major global concern and awareness of the resistance patterns of Salmonella could be very useful in treatment of diseases.

This study aimed to investigate Salmonella serotypes in foodborne outbreaks by sequencing of ITS region of 16S-23SrRNA gene and to determine their antimicrobial susceptibility pattern.

A total of 614 diarrheal stool samples were collected from 173 foodborne outbreaks in different provinces of Iran during one year. Identification of Salmonella was carried out by phenotypic and molecular (16s-23srRNA gene detection) methods and antibiotic susceptibility was performed using disc diffusion method.

Out of 614 samples, 18 isolates were identified as Salmonella of which 16 (88.9%) isolates were Salmonella Enteritidis and 2 (11.1%) isolates as Salmonella Paratyphi A. All isolates were sensitive to ceftazidime, and high resistance was seen with nalidixic acid with 14 (77.8%) isolates.

Increasing antibiotic resistance in many bacterial pathogens such as Salmonella has been a major threat for human health. Therefore, identifying the antibiotic resistance patterns of Salmonella serovars may help in treatment of the associated infections.

Fruit juices are an important part of modern diets that can infect various gastrointestinal tract infections if infected with pathogenic bacteria. The aim of this study was to determine the Frequency of Yersinia enterocolitica in traditional fruit juices shop in southern part of Tehran.

This was a descriptive cross-sectional study, 100 samples of fruit juice including orange juice, mango, carrot, apple and celery(5 samples from each fruit juice shop) were collected from south of Tehran and examined according to the national standard of Iran number 2946 and 9236 for Escherichia coli, Salmonella, Shigella and Yersinia enterocolitica. Data were analyzed using descriptive statistics and SPSS19 software. 

The rate of contamination by Yersinia enterocolitica was 2% followed by Escherichia coli 25%, Shigella 14% and Salmonella 1% respectively. The Escherichia coli were isolated from all the tested fruit juice samples, Shigella in carrot and celery, and Yersinia enterocolitica in mango and apple and Salmonella in carrot juice.

The results of this study suggest more attention and regular checking should be paid in preparation of juices in order to minimize the rate of 
contaminations to public health.

Salmonella enterica is one of the predominant causes of the food-borne salmonellosis in humans. The aim of this study was to determine antimicrobial resistance patterns of Salmonella enterica isolated from stool samples of children with gastroenteritisin in Tehran, Iran.

Stool samples of patients with diarrhea in a pediatric hospital in were collected from June 2017 to May 2018. Microbiological methods were used for identification of Salmonella. The identity of Salmonella enterica serotype enteritidis (S. enteritidis) was also confirmed by a multiplex-PCR. Antibiotic susceptibility testing was performed according to the standard procedure of the Clinical and Laboratory Standards Institute (CLSI).

Of 800 samples, 24 were identified as Salmonella. The most prevalent serotype was S. enteritidis (n=10, 41.7%), followed by S. paratyphi C, (n=6, 25%), S. paratyphi B (n=4, 16.7%), S. arizonae 2 (n=2, 8.3%), and S. paratyphi A (n=2, 8.3%). The highest rates of antibiotic resistance were obtained for nitrofurantoin (100%), followed by nalidixic acid (45.8%), and tetracycline (16.7%). Of 24 S. enteritidis, 9 distinct antibiotypes (Abs) were observed. In this respect, 3 isolates (12.5%) were resistant to at least three or more antibiotics. The most prevalent antibiotype was AB1 (n=8, 33%), which was indicative of resistance to nitrofurantoin.

Considering the constant changes in antibiotic resistance patterns among food-borne pathogens over time, continuous monitoring of multidrug-resistant Salmonella isolates would definitely improve infection control strategies.

Visceral leishmaniasis (VL) is the most severe form of leishmaniasis in Iran with high mortality rates in the case of inaccurate diagnosis and treatment. This study aimed to prepare and evaluate a new rk39 recombinant antigen from an Iranian strain of Leishmania infantum for diagnosis of VL in humans and dogs.

rK39-based enzyme-linked immunosorbent assay (ELISA) was compared with the direct agglutination test (DAT) for the detection of anti L. infantum antibodies. We screened 84 human sera and 87 dog sera from clinical cases in the endemic area of Meshkin-Shahr, Iran along with 176 sera from healthy controls (collected from 86 humans and 90 dogs) during 2013 -2016.

Using the rK39 ELISA, a sensitivity of 85.7% (95% CI, 95-99%) and a specificity of 86.0% (95% CI, 95%-99%) were detected in human sera at a 1:800 (cut-off) titer when DAT-confirmed cases were compared with healthy controls; a sensitivity of 96.6% (95% CI, 95%-99%) and specificity of 94.4% (95% CI, 95%-99%) were found at a 1:80 (cut-off) titer compared with DAT. Kappa analysis indicated agreement between the rK39 ELISA and DAT (0.718) when using human sera at a 1:800 (cut-off) titer as well as (0.910) at a 1:80 (cut-off) titer when using dog sera (P<0.05).

New rk39 recombinant antigen from an Iranian strain of Leishmania infantum seems to be used for diagnosis of VL in humans and dogs. Further extended field studies are recommended.

Echinococcus granulosus parasite causes a zoonotic disease which is important for public and veterinary health. Since pumpkin seeds (Cucurbita sp.) are used as traditional vermifuge in Iran, they may be a potential herbal anthelmintic.

This study was designed in 2016 to evaluate the in vitro scolicidal effect of Cucurbita moschata seeds form northern part of Iran. Hydroalcoholic and petroleum ether extracts were prepared by maceration and soxhlet respectively. Both extracts with four different concentrations (100, 10, 1, 0.1 mg/ml) were incubated against protoscoleces in 5, 15, 30 and 60 min.

Maximum mortality was 16% with 1% hydroalcoholic extract in 60 min. The highest mortality with organic extract was 4% with 10% concentration in 60 min (P=0.015).

Since highest mortality was 16%, the extract did not reach to LD50 (50% mortality). Therefore, the potency of the total extract is not sufficient as potential scolicidal drug.

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.

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.

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.

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.

In today’s world, antibiotic resistance is inevitable. This has been the case since the discovery of antibiotics. The aim of this research is to study serotyping and multiple antibiotic resistance pattern of Shigella sonnei isolated from diarrheal stool of patients hospitalized in Children’s Medical Center in Tehran.
In this descriptive study, 600 diarrheal stool specimens were obtained from patients hospitalized in Children’s Medical Center in Tehran over a period of twelve months. The stool samples were collected in Cary-Blair transport medium and transferred to the laboratory. The identification was carried out according to the standard cultivation method, and the antibiotic susceptibility test was performed by Kerry Bauer disk method according to with CLSI procedure.
Out of 600 samples, only 18 (3%) were found to be contaminated with Shigella sonnei. The results of antibiotic resistance patterns of these isolates showed that they were resistant to tetracycline; streptomycin, clindamycin and cortimoxazol. Furthermore, 66.67% of isolates had multiple resistance to tetracycline, cortimoxazol, streptomycin, ticarcillin and clindamycin antibiotics.
The results of this study showed that multiple resistance of Shigella sonnei to tested antibiotics is increasing. This is alarming; necessary steps should be taken to prevent such a phenomenon.

Visceral leishmaniasis (VL) caused by Leishmania infantum is the most severe form of leishmaniasis in Iran, which causes a high mortality rate in the case of inaccurate diagnosis and treatment. This study aimed to clone of K26 gene from Iranian strain of L. infantum and register the sequencing results in Genbank to facilitate the preparation a new K26 antigen for the detection of L. infantum infection.
L. infantum was obtained from an infected domestic dog in Meshkin-Shahr area from northwestern Iran in 2015. Canine visceral leishmaniasis was confirmed by direct agglutination test (DAT), rK39 dipstick and parasitological methods. L. infantum was confirmed by N-acetyl glucosamine -1-phosphate transferase (nagt)–PCR and its sequencing. The band of interest for k26 form Iranian strain of L. infantum was purified by gel extraction kit after PCR amplification and then ligated into pBluescript II SK () and pET-32a (), respectively. The sequences of recombinant plasmids were analyzed and submitted to Genbank.
The submission of rk26 nucleotide sequence was performed to the GeneBank/NCBI Data Base under accession number KY212883. The related gene was showed a homology about 99% to L. chagasi and L. infantum k26 gene, while the level of homology in comparison with different strains of L. donovani ranged from 84-94%.
The successful rk26 cloning into an expression vector performed in this study could help to produce a new recombinant antigen for serodiagnosis of VL especially in areas where L. infantum is the main causative agent.

Yersinia is a genus in the family Enterobacteriaceae that its species includeYersinia enterocolitica, Yersinia intermedia, Yersinia frederiksenii, and Yersinia kristensenii. Among these species, Yersinia enterocolitica is the most important one that causes various diseases such as gastroenteritis, mesenteric lymphadenitis, and erythema nodosum. Since antibiotic-resistance makes some problems in the treatment of diseases caused by these groups of bacteria, this study was designed to determine the relationship between serotypes and minimum inhibitory concentration (MIC) of Ampicillin, Cefazolin, and Cefotaxime in Yersinia isolates and also the sensitivity of Yersinia to these antibiotics.
In this descriptive study, 50 different strains of Yersinia (39 ones isolated from human, environmental, and food resources of Iran, and 11 ones purchased from Pasteur Institute of Paris) were used to determine MIC of three selected antibiotics using broth macrodilution test.
Cefotaxim showed the lowest MIC (≤ 0.125μg/ml) indicating that it can be used as the most effective antibiotic against Yersinia-related infections. All the species showed 100% resistance to Ampicillin and very low sensitivity to Cefazolin.
Among four studied species, Yersinia kristensenii and Yersinia frederiksenii were respectively the most sensitive and the most resistant species to Beta-lactam antibiotics. Yersinia enterocolitica and Yersinia intermedia compared to the others showed intermediate sensitivity.

In recent years, changing the infant feeding methods and the growing trend of use powdered infant formula (PIF) has raised concern about quality and health assessment among them. These products are contaminated with various pathogenic bacteria such as Bacillus cereus which the presence of this bacteria in PIF is important because of consumer age group and virulence of this bacteria in PIF. The aim of this study was to determine the frequency of Bacillus cereus in powdered milk infant formula consuming in neonatal intensive care unit (NICU) in Tehran hospitals in 2013-14.
Material and In this cross-sectional study, 125 samples of powdered infant formula milk which were used in Neonatal Intensive Care Unit (NICU) were surveyed during 8 month in 2014. Isolation and identification of microorganisms (including Bacillus cereus) were carried out according to FDA standard protocol (FDA method) on B. cereus selective agar (MYP Agar).
The results of present study showed that of 125 samples from of consumable powdered infant formula milk, 84 (67.2%) samples were contaminated with B.cereus and also 18 (14.4%) samples were contaminated by more than one B.cereus species.
As regards pasteurization process is not effective on the spore of B.cereus., The spores of these bacteria can remain in PIF and can cause food poisoning in infants. For this purpose, more attention to quality control of production units and imported powder milk is recommended in Iranian infant foods.

Burns and its complications are regarded as a major problem in the society. Skin injuries resulted from ultraviolet radiation, radioactivity, electricity or chemicals as well as respiratory damage from smoke inhalation are considered burns. This study aimed to determine the epidemiology and outcome of burn patients admitted to Motahari Hospital, Tehran, Iran.
Two hundred patients with second-degree burns admitted to Motahari Referral Center of Burn in Tehran, Iran. They were studied during a period of 12 months from May 2012 to May 2013. During the first week of treatment swabs were collected from the burn wounds after cleaning the site with sterile normal saline. Samples were inoculated in blood agar and McConkey agar, then incubation at 37 C for 48 hours. Identification was carried out according to standard conventional biochemical tests. Treatment continued up to epithelial formation and wound healing. Results of microbial culture for each patient was recorded. Healing time of the burn wounds in patients was recorded in log books. Chi-square test and SPSS Software v.19 (IBM, NY, USA) were used for data analysis.
Our findings indicate that the most causes of burns are hot liquids in 57% of cases and flammable liquid in 21% of cases. The most cases of burns were found to be in the range of 21 to 30 percent with 17.5% and 7% in male and female respectively. Gram-negative bacteria were dominated in 85.7% and among them pseudomonas spp. with 37.5% were the most common cause of infected burns, followed by Enterobacter, Escherichia coli, Staphylococcus aureus, Acinetobacter and Klebsiella spp.
The results of this study showed that the most cause of burns in both sex is hot liquid. Men were more expose to burn than women and this might be due to the fact that men are involved in more dangerous jobs than female. Pseudomonas aeruginosa was the most common organism encountered in burn infection.

Sesame pudding has the high fat, low water activity and rich nutrients, which provide good conditions for bacterial contamination. The aim of this research was to study the prevalence of Salmonella and Bacillus cereus contamination from pudding and sesame pudding produced by traditional methods in Yazd Province.
In total, 50 sesame and one hundred traditional made sesame, pudding sample was examined for detection of microbial contamination in particular, Salmonella and Bacillus cereus according to National Standardization Organization )INSO) 2395 and 2695.
Out of 100 tested pudding sesame samples 2 (2%) were positive for Salmonella while none of 50 pudding samples had any Salmonella contamination. In total, 7 (7%) of pudding sesame samples and 4 (8%) of pudding were contaminated with Bacillus cereus respectively. In addition, 50% of pudding and 18% of pudding sesame were contaminated with Enterobacteria. Over all the most contaminated samples belong to the pudding samples of Yazd 16 (57%) and Ardakan 56 (25%). Furthermore, 3 (6%) of pudding samples and 10 (19%) of pudding sesame were contaminated with molds.
ž The results of this research show that bacterial contamination of traditional sesame pudding produced in small workshops was relatively higher than the industrial production. The modification of manual production methods, products with the same taste and desired properties, could reduce the rate of contamination especially Salmonella and testing Salmonella should become as a compulsory standards.

Xylanases are widely used in various food industries، including livestock and poultry feed industries، the pulp and paper industry، as well as the pharmaceutical industry. Several strains of microorganisms are capable of producing this enzyme by different mechanisms، Bacilliaceae being one of its important sources at the commercial scale. The culture medium for xylan is expensive and، therefore، it is not economical to use in producing xylanase by Bacillus subtilis S7e. The purpose of this study was to explore the possibility of using industrial-agricultural wastes as a source of carbon and nitrogen in submerged fermentation، for producing xylanase in amounts higher than that which can be produced by xylan culture (10048 U/). The indigenous strain of Bacillus subtilis S7e was cultured in the xylan medium، followed by incubation at 30°، 37° and 40° C. Then the nitrogen sources (rapeseed meal، soybean meal، tomato seeds، tea seeds، peptone، Vinas alcohol، casein، and ammonium sulfate) and carbon sources (molasses، wheat bran، rice bran، rice industry waste، gluten waste، malt waste، whey powder، and bagasse) were substituted for the meat and yeast extracts and the xylan culture medium، respectively. The maximum enzyme activity was observed at 30° C after 48 hours of incubation (6183U/l). Rapeseed meal with an enzyme activity of 10048U/l and molasses with an enzyme activity of 3759U/l were found to be the best nitrogen and carbon sources for Bacillus subtilis S7e، respectively. Based on the findings of this study، f rom an economic point of view، agricultural-industrial wastes (rapeseed meal and molasses) are an excellent substitute for the more expensive culture media currently in use for producing the enzyme xylanase.

Shigella species are the major cause of foodborne outbreaks in world and in developing countries. The antibiotic resistance patten of such microorganisms for the treat foodborne diseases is vital, The aim of this study was to isolate the most common serotype of Shigella responsible of food bore disease, and determination of their antibiotic rseistance paterns. This was a descriptive study. In total 305 stool samples of patients that cosumed contaminated foods and had diarrhea, fever and cramp were collected.The samples were for culture, sero-grouping,and antibiogram. Among 305 examined samples collected from different provinces 6.9% were idntified as Shigella spp.The Shigella Sonnei was the most common type(71.5%), and Yazd provinces with (52.3%) was the most abundent, while 39% of isolate were collected in autumn. The results of antibiotic suseptibility showed that 100% of serotypes were sensitive to ciprofloxacin,and All cerotypes were resistant to trimethoprim-sulfamethoxazole. Shigella species are one of the main causes of foodborne related outbreaks. The knowledge of bacterial agent of foodborne diseases and determination of antimicrobial resistance pattern are helpful to reduce the rate of foodborne outbreaks, the cost of treatment.The prevention control of outbreaks is also very important.

Salmonella species are the main agent of disease outbreaks in the world. Their antibiotic resistance made a global challenge in their treatment and good knowledge about antimicrobial pattern of microorganisms is very important to treat foodborne diseases. Hence, determination of their frequency and the most frequent salmonella spp serotype in Iran and their antibiotic resistance profile were the main aims of this study. In this study, 305 stool samples, which had been collected from patients who had same symptoms (diarrhea, fever, cramp) after consumption of contaminated food, were pondered. All samples carefully were examined according to standard culture media, sero-grouping and antibiotic sensitivity test. Among 305 examined samples collected from different provinces, 1.6% of positive cultures were Salmonella spp. Detected Salmonella isolates consist of just Typhi and Paratyphi C types with 50% of each. 61.2% of total positive Salmonella isolates belong to Hamedan province. 55.5% of total Salmonella isolates detected from samples, which had been collected in the spring. 100% of serotypes were sensitive to ciprofloxacin. All serotypes were resistant to trimethoprim-sulfamethoxazole. Salmonella species are one of the main causes of foodborne related outbreaks. Having good knowledge about type of bacterial agent of foodborne diseases and also its medicine resistance pattern plays a very important role to reduce foodborne outbreaks, treatment, prevention and outbreak control activities.

Diarrhea is the most common bacterial infections, and the main cause of death in the children. Worldwide, food and waterborne diseases are estimated to cause more than two million deaths per year. Foodborne diseases and resistance to antimicrobial agents are two problems worldwide and are increasing. However, standard surveillance systems do not routinely collect information on controls. The aim of this study was to analysis epidemiological data of foodborne outbreaks at the country level. This is a descriptive study, in total 305 fecal swab samples from 73 outbreaks during one year from April 2012 to March 2013 in different provinces of Iran, were collected and transferred to the microbiology laboratory of Public Health School of Tehran University of Medical Sciences to identify the cause’s diarrhea. The patterns of antibiotic-resistance were determined by using Kirby Bauer method. In total 73 food borne outbreaks that were studied, the largest number 26 (35.6%) were found in Hamadan province with 103 samples (34.2%). Out of 73 outbreaks 40 (54.79%) of were related to foods, 6 (8.22%) to water, and 27 (36.98%) were unspecified (P< 0.0001). Fifty seven outbreaks (78.08%) in the city and 16 outbreaks (21.92%) occurred in rural areas (P< 0.0001). The most dominated Gram-negative isolated organisms were Shigella (6.9%) and Gram-positive bacteria Staphylococcus aureus (12.8%). The dominated age group was under five years (16.4%), and dominant gender group was men 186 (61.8%) (P< 0.0001). In total 69 (22.9%) were hospitalized and 11 deaths were reported. Most clinical symptoms of abdominal cramping (82%), nausea and vomiting (68.4%), bloody diarrhea (23.3%), and non-bloody diarrhea (76.7%). All the isolated gram-negative were sensitive to ciprofloxacin and resistant to clindamycin. The gram-positive were sensitive to cephalexin and resistant to penicillin. The knowledge of bacterial agent of foodborne diseases and determination of antimicrobial resistance pattern are helpful to reduce the rate of foodborne outbreaks, the cost of treatment. The prevention control of outbreaks is also very important.

Yersinia species are gram negative bacteria that are responsible to cause diarrhea in humans. Due to insufficient knowledge on the effect of pH and temperature in virulence properties of Yersinia spp, this study was conducted to evaluate these factors on virulence properties Yersinia. This was an experimental study performed in two stages on 12 virulence and 7 non-virulence such as Y. enterocolitica, Y. intemedia, Y. fredeniksenii, and Y. kristensenii, which were isolated from different sources. In the first part the impact of pH and temperature on bacterial growth and in the second part of the study the effects of pH and temperature on virulence characteristics of Yersinia spp. were studied by using auto- agglutination test, dependence on calcium, crystal violet, esculin and salicin tests, invasion of Hep-2 cell and RPMI-1640. Temperature and pH were effective on bacterial growth independently without influencing each other. The results showed that temperature was effective on virulence characteristics while pH did not reduce the virulence effect. Furthermore, crystal violet, RPMI-1640 and invasion of Hep-2 cell were more effective in virulence factor. Besides some strains maintained the virulence property during the growth, this might be due to stability of plasmid in such strain. The results showed that both pH and temperature were effective on the growth, but only temperature is effective on virulence properties.

Otitis media is one of the most common infectious diseases in children. Approximately 85% of children will have otitis media at least once by the age of 3 months, and nearly 50% of children would have more than three times. The objective of the this research was to detect Haemophilus influenza, the most common cause of otitis media in children, and to determine the antibiotic susceptibility pattern of this organism. In this cross-sectional study,a total of 102 specimens were collected during 6 months period from patients with otitis media referred to Amir Alam Hospital in Tehran.Specimens were evaluated for Haemophilus influenzae by microscopic examination and culture. The antibiotic susceptibility test was performed by disk diffusion method of Kirby-Bauer and sensitivity rate of tested antibiotics were assessed by evaluation diameter of the growth inhibitory zone. Out of 102 tested specimens, 7 (6.9%) were identified as Haemophilus influenzae. The rate of sensitivity of isolated Haemophilus influenzae to different antibiotics was trimethoprim (100%), vancomycin (85%), streptomycin (57%), tetracycline (57%), and doxycycline (56%),and the rate of resistance to gentamycin (85%), carbenicillin (70%) and cefixime (70%), clindamycin (70%) amikacin (57%) amoxicillin (57%). With respect to appearance of new resistance species especially to clinidomycin, amikiacin and amoxicilin it is recommended to perform antibiotic susceptibility tests before the initiation of treatment.

Along with the constant increase in world population and consequently, the growing need to provide cellulose, as the most abundant organic substance in nature to produce cellulose products, concerns regarding the possible contamination of these products might cause skin, and genital and urinary infections. The aim of this study is to determine the possible microbial contamination of these products supplied in the city of Tehran. This is a descriptive study on 200 samples of unexpired cellulose products including napkins, nappies, sanitary napkin, and cardboard boxes to carry sweets. Fifty samples were obtained in the city of Tehran during six months from September 2011 to February 2012. Microbial contamination was investigated according to the procedure proposed by the Institute of Standards and Industrial Research of Iran. The results obtained indicate that 18 samples (9%) exceeded the level allowed for aerobic bacteria and molds in one gram of specimens. Besides, 16 samples (8%) were contaminated with at least one of the following bacteria: Streptococcus Group D, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. A total of 34 samples (17%) could not be consumed. The least and the most contaminated products were sanitary napkins (0.5%) and cardboard boxes to carry sweets (5%), respectively. The presence of pathogenic bacteria in cellulose products that could cause skin, and genital and urinary tract infections asks for more control over such sanitary products.

Septicaemia is a leading cause of morbidity and mortality of infant’s and childerens espicially in first week of their life، both in developed and underdeveloped countries. The aim of this research was to study of bacterial agents causing septicaemia and to determine their antibiotic suseptibility patternes. This was a descriptive study، it was performed during eight months from October 2011 till May 2011. In total 216 blood culture samples of children suspected of septicaemia in children health centre hospital were send to the laboratory for investigation. The bacterial identification was carried out by culturing and conventional biomedical tests. The antibiotic sensitivity tests were performed by disk diffusion method. These data are analyzed by SPSS and the results Expressed as relative frequencies. Out of 216 tested samples 55 (25. 6%) were positive and 161 (74. 54%) negative. The dominated bacteria was Escherichia coli (31. 42%)، followed by Staphylococcus aureus (22. 86 %)، Klebsiella pneumonia (20%))، Staphylococcus epidermidis (14. 28%)، Streptococcus pneumonia (2. 86%)، Salmonella typhi (2. 86%)، Enterobacter cloacae (2. 86%) and Stenotrophomonas maltophilia (2. 86%). In general gram-negative bacteria were isolated more than gram-positive. Staphylococcus bacteria were more resistant to antibiotics than other isolated bacteria، and were 100% resistant to penicillin. The enterobacteriaceae were more sensitive to norfloxacin، amikacin، tobramycin، and they were 100% resistant to ampicillin. The results obtained in this study showed that gram-negative bacteria are more responsible in septicaemia in children ward، and norfloxacin is the more effective antibiotic in comparison with others.