فهرست مطالب محمدکاظم شریفی یزدی

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.

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.

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.

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.

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.

Diarrhea is one of the most important causes of children mortality in developing countries. Gastroenteritis causes mortality in children younger than five years old annually. The presence of antibiotics resistance species among these bacteria are major health problems.
This study aimed to determine the antibiotic susceptibility and MIC50%, MIC90% of Yersinia to three beta-lactam antibiotics.
This experimental study was determined sensitivity of different species of Yersinia to three beta-lactam antibiotics (Ampicillin-Cefazolin-Cefotaxime). In total 50 species (39 from different human sources, environments, foods and 11 from Pasteur institutions in Paris) were used. Minimum inhibitory concentration (MIC) was carried out by serial dilution method.
Findings: Among three tested antibiotics, the lowest MIC 50%, MIC 90% were obtained for Cefotaxime (≥0.125μg/ml and 0.5μg/ml). All the tested species showed resistance to Ampicillin and very low sensitivity toward Cefazolin.
The results showed that Cefotaxime was more effective against Yersinia species in compared to Ampicillin and Cefazolin.

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.

Yersinia is a gram-negative bacillus that cause diarrhea through consumption of contaminated food and water. This study was performed to identify the atypical Yersinia virulence markers isolated from children with diarrhea.
This descriptive cross -sectional study was done on 384 fecal samples of 0- 14 years old children admitted at children medical center from August 2011 to August of 2012. Fecal samples, for the enrichment, after 21 days of incubation in alkaline buffer with pH=7.2 at 4degree C, on days 7, 14 and 21 samples were cultured on CIN agar and Mac agar and then confirm the differentiation atypical Yersinia from other typical Yersinia species from fermentation of different sugars. Isolates were tested for marker of virulence including calcium dependence, auto agglutination, Congo red uptake and binding of crystal violet.
Out of 384 stool samples, 4 (1.04%) were infected with Yersinia (Yersinia frederikseni, Yersinia kristensenii and Yersinia enterocolitica). Out of these three, only two samples in association was positive with virulence markers.
Phenotypic markers can be used to study the properties of phenotypic strains of Yersinia.

The increasing use of industrial dairy products instead of traditional might resulted in elimination of probiotic bacteria. The purpose of this study was isolation and biochemical identification of potentially Probiotic lactic acid bacteria isolated from traditional yogurt produced from milk of goat, cattle and sheep in Yazd province.
96 yogurt samples ,33 each from goats ,sheep and cow were collected from different parts of Yazd province. Samples were enriched in MRS broth, and then cultured on MRS agar.Suspected colonies were primary tested for catalase and gram stain. Lactic acid bacteria with probiotic characteristics were identified with biochemical tests including fermentation of carbohydrates, grown at 15 and 45 ° C, hydrolysis of arginine, gas production from glucose and their probiotic activity were investigated by means of resistance to acid and bile.
In general out of 75 positive samples, 47 were identified as lactic acid bacteria on the bases of phenotype and biochemical tests, in which 24 were resistance to acid and out of these 12, were resistant to bile, which had a probiotics potential. Five of them were identified as Pediococcus acidilacticii, and isolated from Sheep and goat yogurt. Another 6 probiotic isolates belonged to the genus Lactobacillus and included as L. plantarum, L. brevis, L. fermentom and L. kefiri and isolated from goat and sheep yogurt Yazd province.
The findings of this study indicate high diversity of lactic acid bacteria in traditional yogurt in Yazd province

Acute otitis media (AOM) remains a frequent global infection of childhood. This study was conducted to determine the frequency of Staphylococcus aureus and Pseudomonas aeruginosa and determine the antibiotic susceptibility patterns in patients with acute middle ear infections referred to Amir Alam hospital. In total 102 middle ear discharge specimens were collected during 6 months period from patients with acute otitis media. Specimens were assessed for isolation and identification by microscopic examination and culture. The antibiotic susceptibility test was done by disk diffusion method of Kirby-Bauer and sensitivity frequency of tested antibiotics was assessed by appraisal diameter of the growth inhibitory zone. Of 102 tested specimens, 90 (88.2%) were recognized as Staphylococcus 27(26.5%), Streptococcus 7(6.9%), Moraxella catarrhalis 2(2%), Proteus 11(10.8%), Streptococcus pneumonia 15(14.7%), Pseudomonas15 (14.7%), Corynebacterium 6(5.9%), Haemophilus influenza 7(6.9%) and 12(11.8%) specimens were non cultureable. Almost all the isolated bacteria to antibiotics that are commonly prescribed to patients by Physician routinely including penicillin, ampicillin, and amoxicillin showed resistance. According to the emergence of resistant strains to conventional antibiotic therapy, especially beta-lactam antibiotics and erythromycin, it is recommended to perform further studies to determine full picture of antibiotic susceptibility in circulating in patients with AOM to revise existing guidelines of empirical therapy of AOM in Iran.

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.

Occurance of severe diseases by bacteria that are considered as normal flora poses a threat to human life. Bacteria such as Klebsiella, Enterobacter, and Serratia, which are all VP +, cause the urinary tract infection. The antibiotic-resistant strains of these bacteria create problems in the process of treatment. The aim of this research was to compare the multiple antibiotic resistance patterns of Klebsiella, Enterobacter, and Serratia causing urinary infections and determine the imipenem MIC in MDR strains. In this experimental study 400 urinary specimens from UTI patients who had referred to Imam Khomeini Hospital (Tehran) were collected using the midstream clean catch method. The klebsiella groups were identified by conventional methods. The antibiotic sensivity test was carried out by disk diffusion and macrodilution broth test methods. Of 400 patients with urinary tract infections, 96 (24%) were caused by Klebsiella groups (KES. Maximum and minimum resistances were to amoxicillin and amikacin, respectivey. MIC and MBC determined using serial dilution method and showed that the concentration range of imipenem that stopped growth of Klebsiella pneumoniae and Serratia marcescens were in the range of 0. 25- 16 and 8-0.25 μg / ml, respectively. The results of this study suggest that imipenem is an appropriate medication for the treatment of Klebsiella group infections.

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.

Attention has largely been focused on appearance of multiple drug resistance enterococci in the last 20 years. One of the methods to overcome this problem is to combine different antibiotics in order to increase antimicrobial activity and reduce toxicity. The combination of fluor quinolones with other antibiotics has been widely investigated. The aim of this study was to investigate the synergistic effect of ciprofloxacin in several antibiotics Beta-lactam (piperacillin, ceftazidime and imipenem) on isolated enterococci. In this cross sectional study, 67 Streptococci strains were isolated from clinical samples from March to September 2012. The serial broth dilution method in test tubes was used for the MIC, and the check board Format was used for the synergistic effect of ciprofloxacin with Beta-lactam antibiotics. The synergistic effect was determined with four- fold reduction of initial MIC. Totally, 67 strains of Streptococci were used, in which 50 strains (74.6%) were enterococci, 6(9%) were group B streptococcus, 5(7.5%) were non-group A streptococci, 2 (3%) were pneumococci, and 2 were strains of alpha streptococci (3%), respectively. All results were determined by the MIC and MBC of each antibiotic individually and also in combination with ciprofloxacin. The effect of ciprofloxacin on other antibiotics was indifferent, and the synergistic effect was not observed.

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.

Gastroenteritis due to Salmonella is common in human and considered as a global dilemma of public health. This study was done to determine the Pattern of serotyping and antibiotic resistance of Salmonella in children with diarrhea in Iran. In this laboratory study, 306 stool samples were collected from children with diarrhea in public health centers in Robat-karim, Tehran province, Iran. The specimens were enriched in Selenite F medium and then cultured on Hekton agar. The identification of Salmonella was carried out by conventional method and antimicrobial susceptibility testing was performed according to CLSI procedures. Out of 306 stool samples, 7.2 % were identified as Salmonella species, as follow: 7 Salmonella typhi, 6 Salmonella paratyphi B, 3 Salmonella paratyphi C, 2 Salmonella paratyphi A and 4 samples were not identifiable. There was a significant relation between presence of WBC in fecal and salmonellosis (P<0.05). In drug sensitivity trends, 92.3% of Salmonella species were sensitive to chloramphenicol, ceftizoxime, Nalidixic acid and Amikacin. This study showed that Salmonella was the cause of children diarrhea in 7.2% in this region.