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Background and Objective:Acinetobacter baumanniiis a non-motile Gram-negative bacterial pathogen with the history of vast resistant to antibiotics. The aim of this study was to determine the possibility of existence of OXAs genes among clinical isolates ofA. baumanniiobtained from Tehran hospitals.Materials and Methods:A total of 101 isolates were identified asA. baumanniiby common biochemical and molecular tests. The susceptibility to different antibiotics was assessed with Kirby-Bauer disk diffusion method. Phenotypic Detection of MBLs was performed with CDT test and PCR assay was also performed for detection ofblaOXA-23-like,blaOXA-24-like,blaOXA-40-like,blaOXA-51-like,blaOXA-58-likeandblaOXA-143-likegenesResults:All isolates ofA. baumanniishowed high-level of resistance to all antibiotics except for Polymyxin B. TheblaOXA-51 likegenes was found in all of the isolates and the prevalence ofblaOXA-143like,blaOXA-23like,blaOXA-40likeandblaOXA-24likewere 56%, 45.45%, 33% and 11.8%, respectively.Conclusion:TheblaOXA-51-likewas the predominant mechanism of resistance to imipenem inA. baumanniiand therefore, early recognition of carbapenem-resistantA. baumanniiisolates is a useful tools to prevent their spreading within the hospital environment.

Background:Salmonella entericahas become increasingly resistant to antimicrobial agents, partly as a result of genes carried by integrons.Objective:The aim of the present study was to investigate the prevalence of class 1 and 2 integrons and resistance to antimicrobial agents in clinical isolates ofS. enterica.Methods:This study included allSalmonellaisolates, recovered from patients with salmonellosis, admitted to Medical Children Hospital, Tehran, Iran during 2015-2016. Bacterial isolates were identified using standard biochemical and agglutination tests. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines. The presence of class 1 and 2 integrons was investigated by Polymerase Chain Reaction (PCR) assay, using specific primers.Results:A total of 138Salmonellastrains were isolated and included in this study. Integrons were detected in 45 (32%) isolates. Class 1 and 2 integrons were detected in 24 (17.3%) and 21 (15.2%) isolates, respectively. All integron-positive isolates showed multidrug-resistant phenotypes. Resistance to more than three antimicrobial agents was observed in integron-positive isolates.Conclusions:Our findings showed that integrons were widely distributed amongS. entericaisolates in Tehran. Class 1 integrons are more prevalent than class 2 integrons inSalmonellaisolates, and there is an association with MDR patterns. Therefore, these integrons are more likely to be involved in the distribution of resistant phenotypes inSalmonellastrains.

Helicobacter pylori is a Gram-negative motile bacterium causative agent of acute and chronic digestive and extra-digestive human infections. According to different reports worldwide, H. pylori symptomatic and asymptomatic infections are a global problem. The statistical investigations show a percentage of 50 for people who are involved in H. pylori acute/chronic digestive and/or extra-digestive infections around the world. This review focuses on digestive and extra-digestive diseases caused by H. pylori, the related virulence factors, diagnostic techniques including non-invasive and invasive diagnostics and treatment. There is an abundance of diagnostics for detection and identification of H. pylori. The availability, cost, and the condition of test performance may differ from place to place. To increase the level of reliability in association with diagnostic tools for detecting H. pylori, several techniques must be applied at once as multi-diagnostic technique. Furthermore, there are several pharmacotherapies which can be used for complete eradication of H. pylori infection.

Antibiotic resistance in Acinetobacter baumannii is a major problem in the hospital and outbreaks caused by this organism have been reported frequently. The present study aimed at determining the antibiotic susceptibility patterns, the prevalence of different classes of integrons and the characterization of integron class 1 gene cassettes in Iranian A. baumannii isolates. A total of 63 non-duplicate A. baumannii isolates were collected from clinical and environmental specimens in the Vali-Asr hospital in the central province of Iran (March to September, 2011). The antimicrobial susceptibility for 15 antibiotics which are used conventionally was determined by disk diffusion. The presence of different integron classes was investigated by PCR and the size of gene cassettes in class 1 integrons was then determined by PCR as well. Moreover, integron cassette arrays of isolates were delineated by RFLP and sequencing amplicons with different lengths. Of 63 isolates 62 (98.4%) carried a class 1 integron. The prevalence of IntI2 was 15.9% and the length of the amplicons ranged from 500 bp to 3 kb. Sequencing of integrons of class 1 revealed the presence of many resistance genes (aadA, aacA, aacC, dfrA, bla(GES) and bla(IMP)). We identified a completely new gene cassette which contained aacA7-qacF-aadA5-bla(IMP), this cassette has not been reported previously in A. baumannii.

Although Helicobacter pylori (Hp) plays an important role in the pathogenesis of chronic gastritis and gastric ulcer, little is known about the probable mechanisms of these types of gastrointestinal damage. To determine the precise mechanisms involved in ulcer formation, immune responses in patients with gastric ulcer (GUP) caused by Hp infection (Hp(+)) were compared with those of other gastritis patients (GP). The sensitivity and proliferation of peripheral blood mononuclear cells (PBMNCs) obtained from patients were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against exposure with complex Hp crude antigen (HPCA) and mitogen (phytohemagglutinin, PHA). Production of inflammatory cytokines, including interleukin (IL)-1β and IL-8, in serum and supernatants of PBMNCs were then measured by ELISA. It was found that, after stimulation with PHA, both IL-8 and IL-1β concentrations in sera and supernatants as well as proliferation and sensitivity were statistically greater in GUP Hp(+) than GP Hp(-) . Furthermore, HPCA inhibited the proliferation of PBMNCs dose-dependently; however, it stimulated IL-8 and IL-1β production in supernatants of mononuclear cells. Therefore, the up-regulated concentrations of IL-8 and IL-1β may have been caused by increase in the size of mononuclear cell subpopulations or in their cytokine secretory activity, indicating the greatest cell responsiveness in GUP Hp(+) patients. These results suggest that tissue damage and ulcers occur in patients who produce more IL-8 and IL-1β than patients who do not develop ulcers; the former consequently have more activated immune cells at the site of infection. Therefore, both host responses and Hp virulence factors may be involved in the development of gastric ulcers.

The present study was conducted to investigate serotype distribution, antimicrobial resistance patterns, carriage of class 1 integron, and clonality of Salmonella strains isolated from patients aged 0-12 years in Tehran, Iran, during 2007-2008. A total of 139 Salmonella isolates were studied. Salmonella serotypes Enteritidis, Infantis, and Typhimurium included 84.9% of isolates, Enteritidis accounting for 41.7%. The most prevalent resistances were to doxycycline (64.7%), nalidixic acid (61.2%), tetracycline (51.8%), and streptomycin (42.8%). Fifty-three (38.1%) isolates contained class 1 integron. Eight different gene cassettes were identified, aadA1 being the most frequently encountered. Pulsed-field gel electrophoresis showed that integron-positive Salmonella strains belonging to serotypes Infantis, Enteritidis, and Typhimurium were attributed to two, three, and five different pulsotypes, respectively. The findings indicated that the distribution and drug resistance pattern of most prevalent Salmonella serotypes were broadly similar to that reported globally from human isolates. Presence of class 1 integrons was common among Salmonella serotypes in Tehran, Iran. Concurrent clonal expansion and horizontal transmission events seem to contribute to increase in drug resistance prevalence among Salmonella serotypes.

A current phenomenon of great concern among the medical communities in developing countries is rising multi-drug resistant organisms, and the challenges of curing the infections in children. In this study, we evaluated the multi drug resistant strains of Escherichia coli isolated from urinary tract infection in children in southern Iran. Totally, 90 strains of E. coli were collected from urine samples of the children, aged from 1 month to 14 years, referred to Motahary Hospital of Jahrom, Iran. After confirmation of the urine cultures which were expressive of urinary infection, gram stain and biochemical differential test were done for the isolates and their susceptibility patterns to different antibiotics were determined by standard disk diffusion method. The antibiogram patterns of the isolates showed a high percentage of multi drug resistance to ampicillin, co-trimoxazole and tetracycline which was repeated among 13 strains. With regard to the present data and high percentage of multi drug resistant strains of E coli, regular monitoring antimicrobial drug resistance in different areas is necessary to prevent unsuitable utilization of drugs which is responsible for the emerging multi drug resistant strains.

To evaluate the prevalence of virulence genes in E. coli strains isolated from urine samples of children with urinary tract infection(UTI) and their correlation with clinical data, we iso-lated E. coli strains from urine samples of children with UTI during the period of August 2005 - August 2006 and studied them for the presence of the virulence genes by PCR. A total of 96 E. coli strains were isolated. The prevalence of genes, pyelonephritis associated pili (pap genes), S-family adhesions (sfa gene), hemolysin (hly gene), and cytotoxic nercotizing factor type 1 (cnf-1-1 gene) among the isolated strains was 27.1%, 14.6%, 13.5% and 22.9 %, respectively. Pyelonephritis was more prevalent in the cases with positive virulence genes. The results showed significant correlation bet-ween age of the patient and the presence of the genes (P< 0.05). Cnf-1 gene was significantly more common in samples of patients with abnormal finding on the ultrasound of kidneys (P= 0.049). Our study demonstrated higher prevalence of pyelonephritis in the presence of E. coli virulence genes. Detection of the genes in urine samples may help in the management of UTI.

Background Cytotoxin-associated gene A (cagA) is an important virulence factor in the pathogenesis of Helicobacter pylori. Objectives The aim of this study was to genotype the H. pylori cagA gene isolated from antral biopsies of patients with stomach symptoms, using a PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. Patients and Methods A total of 161 gastric biopsies were collected from patients with stomach symptoms. After isolation of H. pylori from the biopsy culture, the cagA gene was assessed using PCR. The PCR products were then digested by the HinfI restriction endonuclease enzyme. A sample of each genotype was also subjected to direct sequencing for further analysis. Results From 161 antral biopsies, 61 (37.9%) were positive for H. pylori in culture. Overall, 24 cagA-positives were detected in the isolates. RFLP indicated three different genotypes (I, II, and III) of cagA with a frequency of 62.5%, 25%, and 12.5% among the isolates, respectively. Genotypes I and II of cagA were predominant in patients who had gastritis. However, genotype III was found in three patients with duodenitis and duodenal ulcers. Alignment of the nucleotide sequences of the three isolated genotypes, with H. pylori 26695 as a reference strain, revealed 12 inserted nucleotides in genotype III. When the sequence of genotype III was aligned with 15 additional H. pylori strains available in GenBank, the same inserted nucleotides were detected in six of them. Conclusions Using the PCR-RFLP method, three distinctive H. pylori cagA genotypes were detected in antral biopsies. Genotype I, which was predominant among the isolates, was significantly associated with gastritis. However, the data showed that cagA genotype III may play a role in duodenitis and duodenal ulcers in patients infected with H. pylori.

Pseudomonas aeruginosa plays a prominent role in serious infections in burn patients. Rapid acquisition of multi-drug resistance leads to high morbidity and mortality, especially in burn centers. Ten antibiotics, which were widely used in our burn patients were selected. MICs for imipenem, mropenem, cefepime, ceftazidime, cafoparazone/sulbactam, ticarcillin/clavulanate, piperacillin/tazobactam, ciprofloxacin, tobramycin and amikacin to 70 strains of P. aeruginosa, which were isolated from burn patients were determined by the E-test method (AB Biodisk, Sweden). Extended-spectrum beta-lactamase, group I inducible beta-lactamases and metallo-beta-lactamase activities were also determined. Imipenem and meropenum were the most active in vitro antibacterial agents followed by ciprofloxacin (p

Background: Identification, understanding of antibiotic sensitivity patterns and molecular characterization of genetic elements of Shigella species are important because of both epidemiological and clinical indications in developing countries. Objectives: The aim of this study was to analyze molecular epidemiology of Shigella isolates recovered from children with diarrhea in Shiraz (Southern Iran), using IpaH and IpaBCD PCR-restriction fragment length polymorphism (RFLP), and to determine pulsed field gel electrophoresis (PFGE) patterns of total DNA of the S. sonnei isolates to find the clonality among these strains. Patients and Methods: A total of 82 clinical strains of Shigella spp., S. sonnei (n = 61), S. flexneri (n = 16), Shigella boydii (n = 3) and S. dysenteriae (n = 2) isolated from the stool samples of 719 patients, aged two months to 14 years, with positive occult blood (OB) test were characterized based on their IpaH and IpaBCD genes PCR-RFLP patterns. Genomic DNAs of S. sonnei strains were analyzed by PFGE. Results: All Shigella isolates were positive for both invasive genes and showed homogeneous profiles for such genes except for two S. sonnei strains, which had IpaH bands with different sizes and PCR-RFLP profiles. Forty palsotypes were determined among the 41 S. sonnei strains. Sample patterns were divided into two groups based on the drawn dendrogram with a similarity range of 70% to 100%. Conclusions: The results revealed that the strains under study could be epidemically related. It seems that an alternative subtyping method is needed to study the relationship among clinical S. sonnei strains and their transmission. Here, we reported for the first time, two strains of S. sonnei with a different PCR-RFLP pattern for IpaH gene.

BACKGROUND: Failure in the treatment of burn patients infected with Pseudomonas aeruginosa could happen as a result of the acquisition of antibiotic resistance, including carbapenems. OBJECTIVES: The aim of the present study was to investigate the phenotypic and genotypic characteristics of the Pseudomonas aeruginosa strains, isolated from burn patients. PATIENTS AND METHODS: During a 12 month period, in this cross-sectional study, two hundred seventy strains of Pseudomonas aeruginosa were isolated from the burn patients in Ghotbeddin Burn Hospital, Shiraz, Iran. Screening for the carbapenem resistance in the isolates was carried out by the E test method. Sensitivity patterns of metallo-β-lactamase (MβLs) producing strains of pseudomonas to eleven antibiotics were determined by the mentioned method. The epidemiological associations of these strains were determined by Pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 270 strains, 60 (22.2%) were resistant to imipenem and meropenem, classified as MβLs producing. MβLs producing strains of pseudomonas were completely resistant to five tested antibiotics while their sensitivities to the three most effective antibiotics including ceftazidime, amikacin and ciprofloxacin were 23.4%, 6.7 % and 1.7%, respectively. In PFGE, 37 patterns from the genome of Pseudomonas aeruginosa were observed. Majority of the strains (43; 71.6%) exhibited more than 80% similarity, based on the drawn dendrogram. CONCLUSIONS: According to the results, none of the tested antibiotics is safe to prescribe. As PFGE revealed, a limited number of Pseudomonas aeruginosa types are predominant in the hospitals which infect the burn patients.

We evaluated the performances of a newly designed real-time polymerase chain reaction (PCR) assay using TaqMan® probes to detectSalmonellaTyphi. TaqMan® real-time PCR assays were performed by designed primers and probe based on thestaGgene for detectingS.Typhi. The specificity of the assay was evaluated on 15Salmonellaserovars. The analytical specificity was evaluated on 20 non-Salmonellamicroorganisms. The analytical sensitivity was assessed using decreasing DNA quantities ofS.Typhi ATCC 19430. Finally the detection capability of the TaqMan® real-time PCR assay on isolates recovered from patients withSalmonellainfections was compared to the conventional PCR assay. OnlyS.Typhi strain had positive results when subjected to the assay using Typhi-specific real-time PCR. No amplification products were observed in real-time PCR with any of the non-Salmonellamicroorganisms tested. The TaqMan® real-time PCR was more sensitive than the conventional PCR. In conclusion, we found that the easy-to-use real-time PCR assays were faster than conventional PCR systems. ThestaG-based TaqMan® real-time PCR assay showed to be specific and sensitive method for the safe and rapid detection of theS.Typhi.

antibacterial activity of the extract with initial concentration of 200 µg /mL was determined by the micro broth dilution method. Results: The obtained results showed that the minimum inhibitory concentration (MIC) varied from 2 to 16µg /mL for strains. It inhibited the growth of S. epidermidis, S. saprophyticus and methicillin sensitive S. aureus (MSSA) by about 8-16 µg/mL. The minimum bactericidal concentration (MBC) of the extract that could destroy 62.2% strains and the other examined bacteria was 512 µg /mL or more. Conclusions: In conclusion, it seems that Z. multiflora extracts could inhibit the growth of all of the mentioned bacteria. We noticed that the bactericidal effect of Z. multiflora extracts was less than its bacteriostatic effects.

Actinomyces naeslundii is one of the normal flora of human oral cavities and is associated with oral plaque. This organism is not virulent and is recognized as a saprophyte organism however it seems that the identification of a primary or secondary immunosuppressant plays a critical role in the etiology of bacteremia. That is, whether A. naeslundii is the causative agent of malignancy or not needs further studies in future. : We report a case of A. naeslundii bacteremia in an 11 year-old boy with persistent fever for two weeks prior hospital admission. He was finally diagnosed with malignant T cell lymphoma. Isolation of this bacterium from the blood culture of our patient can serve as an important warning indicating that incuriosity about fastidious and not easily grown bacteria isolated from clinical samples may lead to misinterpretation and misdiagnosis.

Background: Helicobacter pylori (H pylori) is a common gastric pathogen which is associated with chronic gastritis, peptic ulcer, and gastric cancer. It has worldwide distribution with higher incidence in developing countries. Gemifloxacin is a fluoroquinolone antibiotic with documented in vitro activity against H pylori. Considering that there is no clinical data to verify gemifloxacin efficacy in H pylori eradication, this pilot clinical trial was designed.

Development of a specific immunoassay to detect Helicobacter pylori infection in stool samples requires monoclonal antibody against the specific antigen. The aims of this study were to establish monoclonal antibodies against the 26 kDa protein of H. pylori and develop an immunodot blot for their application to recognize H. pylori infection using stool samples. Mice were immunized intraperitoneally with homogenized gel containing the 26 kDa band of cell surface proteins of H. pylori in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The monoclonal antibodies were produced using the hybridoma technique. Reactivity of monoclonal antibodies was tested with the purified 26 kDa antigen and cell surface proteins from cultured H. pylori by ELISA. Furthermore reactivity of monoclonal antibodies was tested on negative and positive stool samples for H. pylori and suspensions of several major bacteria in stool by immunodot blot assay. Five stable hybridoma monoclones were obtained. The concordant reactivity of the monoclonal antibodies with H. pylori present in the stool samples, which had been tested previously using an ACON ELISA kit for H. pylori stool antigen testing, and unreactivity with several different major fecal bacteria in immunodot blotting indicates high specificity of the immunodot blot based on the reaction of produced monoclonal antibodies with the H. pylori antigen in stools. The findings indicate that the novel immunodot blot developed based on new monoclonal antibodies for stool antigens would be useful as a noninvasive method of diagnosing H. pylori infection.

Although Helicobacter pylori (Hp) plays an important role in the pathogenesis of chronic gastritis and gastric ulcer, little is known about the probable mechanisms of these types of gastrointestinal damage. To determine the precise mechanisms involved in ulcer formation, immune responses in patients with gastric ulcer (GUP) caused by Hp infection (Hp(+)) were compared with those of other gastritis patients (GP). The sensitivity and proliferation of peripheral blood mononuclear cells (PBMNCs) obtained from patients were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against exposure with complex Hp crude antigen (HPCA) and mitogen (phytohemagglutinin, PHA). Production of inflammatory cytokines, including interleukin (IL)-1β and IL-8, in serum and supernatants of PBMNCs were then measured by ELISA. It was found that, after stimulation with PHA, both IL-8 and IL-1β concentrations in sera and supernatants as well as proliferation and sensitivity were statistically greater in GUP Hp(+) than GP Hp(-) . Furthermore, HPCA inhibited the proliferation of PBMNCs dose-dependently; however, it stimulated IL-8 and IL-1β production in supernatants of mononuclear cells. Therefore, the up-regulated concentrations of IL-8 and IL-1β may have been caused by increase in the size of mononuclear cell subpopulations or in their cytokine secretory activity, indicating the greatest cell responsiveness in GUP Hp(+) patients. These results suggest that tissue damage and ulcers occur in patients who produce more IL-8 and IL-1β than patients who do not develop ulcers; the former consequently have more activated immune cells at the site of infection. Therefore, both host responses and Hp virulence factors may be involved in the development of gastric ulcers.

Because resistance to antifungal drugs is seen in patients, susceptibility testing of these drugs aids in choosing the appropriate drug and respective epidemiology. This study has investigated and compared susceptibility patterns of the Aspergillus species isolated from patients by the Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution (MD) assay and Etest method.The minimum inhibitory concentrations (MICs) of various antifungal agents (amphotericin B, ketoconazole, itraconazole, and voriconazole) for 108 Aspergillus species isolated from patients were determined by CLSI M38-A broth MD and Etest. The isolates were obtained from clinical samples that included tissues, sputum, bronchoalveolar lavage, abdominal tap, and cerebrospinal fluid.As revealed by the MD method, 63.9% of the isolates were sensitive to amphotericin B and 36.1% were resistant.Etest revealed that 61.1% were sensitive to amphotericin B and 38.9% were resistant. As for ketoconazole, 108 isolates (100%) were shown to be sensitive through the MD method; while the Etest revealedan 88.9% sensitivity and 11.1% were resistant. All species were susceptible to voriconazole, according to both methods. The measure of agreement (Kappa Index) for these three drugs was satisfactory (≥0.6). According to the MD method, 69.4% of the species were susceptible to itraconazole, whereas 30.6% were not.For this drug, the Etest showed 86.1% susceptible and 13.9% resistant.Voriconazole was the most effective agent against isolates. Using RPMI agar, we found the Etest to be helpful, readily available, and easy to use for determining invitro susceptibilities of Aspergillus species to voriconazole, amphotericin B, ketoconazole, and itraconazole in the region of this study.

Due to increased bacterial resistance to common antibiotics, tendency towards using herbal extracts like Zataria multiflora from Lamiaceae family is increasing. In this study, antibacterial effects of Z. multiflora on several common pathogenic and non pathogenic bacteria were evaluated. Several clinical Gram positive cocci and Gram negative bacilli isolated from patients and healthy humans were identified with standard methods. The extract of Z. multiflora was prepared from dried leaves with maceration method. The antibacterial activity of Zataria extract with initial concentration of 200 µg/ml was determined by micro dilution method. Results obtained showed that the minimum inhibitory concentration varied from 2 to 32 μg/ml for all Gram positive cocci and Gram negative rods while it was 512 μg/ml for Pseudomonas aeroginosa and Shewanella putrifaciance. The minimum bactericidal concentration varied from 4 to 512 μg/ml for examined bacteria. In conclusion, it seems that Zataria extract could inhibit the growth of some clinical Gram positive and Gram negative bacteria. However, the inhibitory effects ofZataria extract for Pseudomonas aeroginsa and Shewanella putrifacians are lower than its inhibitory effects for other Gram negative bacilli in the examined extract concentrations. We noticed that the bactericidal effect of Zataria extract was less than its bacteriostatic effect. Key words: Ethanolic, Zataria multiflora extract, antibacterial effect, pathogenic bacteria.

This paper aimed to study the drug resistance patterns and the reliability of antibiogram and pulsed field gel electrophoresis (PFGE) patterns in epidemiological study of uropathogenic Escherichia coli (UPEC) isolated from the children with community acquired urinary tract infection (UTI). Totally ninety E. coli strains were isolated from urine samples of children with community acquired UTI and tested for susceptibility to fourteen different antibiotics, using disc diffusion method. To study the molecular epidemiology of these strains, their genomic patterns were determined using PFGE. Forty five patterns of resistance have been recognized for the E. coli strains. High prevalence of resistance to ampicillin (80.2%), trimethoprim-sulfamethoxazole (76%), and tetracycline (70.8%) was seen among the UPEC isolates. All the isolates were 100% sensitive to imipenem. In PFGE, sixty five patterns from the genome of E. coli strains were observed. Based on drawn dendrogram the sample patterns were divided into two groups. All the samples except two have different clonalities. In conclusions it seems that imipenem, amikacin and nitrofurantoin can serve as drug of choice for the treatment of UTI caused by E. coli, respectively. With regard to high differentiation power of PFGE method in comparison with antibiogram and according to the obtained patterns and high diversity of these profiles, no epidemic UPEC was determined in the studied population.

Isolation of H. pylori from gastric mucosal biopsy specimens is a prerequisite for further studies addressing drug susceptibility testing, analysis and characterization of virulence factors, molecular epidemiology studying or other comparative studies. In this study, we used a modified enriched culture medium with short incubation time to improve the isolation rate of H. pylori from the clinical specimens.Between October 2008 and October 2009, 266 dyspeptic patients attending the endoscopy ward of Motahhary Clinic of Shiraz University of Medical Sciences, were investigated. The biopsy samples were cultured on two selective media called M1, which we used in our previous studies, and a modified medium called M2. The cultures were kept in a microaerophilic atmosphere at 37 degrees C. The plates were inspected first on day 1, and then on daily basis for a total of 10 days. The isolates were confirmed as H. pylori by colony morphology and positive oxidase, catalase and rapid urease tests. We used the same media and culture conditions to subculture the isolates for several times. Specimens were considered to be H. pylori positive if either the culture or two of the three diagnostic methods yielded positive results.The isolation rate of H. pylori strains from the samples was significantly higher on M2 in comparison with M1 medium (p0.05). The bacterial growth on M2 was observed after a significantly shorter time (p0.05), i.e., after incubation for about 24 hrs. Following these procedures, the preservation time could be extended beyond 6 months without a significant loss of viability.The modified culture technique enabled a shorter incubation time and a higher isolation rate for H.pylori obtained from clinical samples.

This study was carried out from October 2003 to March 2007 to investigated susceptibility patterns ot March 2007 to antifungals of Candida strains isolated from 410 immunocompromised patients in Shiraz, Islamic Republic of Iran. Patients were checked for systemic candidiasis. Fungal colonization was determined and clinical samples collected from those patients with clinical signs of infections were examined. The carbohydrate assimilation patterns of all 354 isolates were studied. Susceptibility of the isolates to antifungal agents was determined using the reference broth microdilution method. Candida albicans was the species most often isolated. Voriconazole was highly active against all the isolates. Major resistance to itraconazole was observed in all Candida spp. Regular investigations into antifungal resistance in medical centres is highly recommended as this will result in more efficient management of invasive candidiasis in immunocompromised patients.

Here we describe two cases of bacteremia caused by Comamonas testosteroni in two malignant patients, a 10-year-old boy with brain medulloblastoma and a 19-year-old girl with osteosarcoma admitted in the same hospital at short intervals. This is the first report in Iran on this low inherent virulence organism as a human pathogen.

AIM: To improve our understanding of Iranian regional variation in Helicobacter pylori (H. pylori) antibiotic resistance rates to find the best antibiotic therapy for eradication of H. pylori infections. METHODS: A total of 266 patients undergoing endoscopy in Shiraz, Southern Iran, were included in this study. H. pylori strains were isolated from antral biopsies by culture and confirmed by the rapid urease-test and gram staining. Antibiotic susceptibility of H. pylori isolates was determined by E-test. RESULTS: A total of 121 H. pylori strains were isolated, 50 from male and 71 from female patients. Data showed that 44% (n = 53), 20% (n = 24), 5% (n = 6), and 3% (n = 4) of all strains were resistant to the antibiotics metronidazole, amoxicillin, clarithromycin, and tetracycline, respectively. When the antibiotics were considered together we found 11 sensitivity patterns for the strains. Resistance to metronidazole was significantly higher in female than in male patients (P < 0.05). In about 71% of the metronidazole-resistant isolates, the minimum inhibitory concentrations (MICs) exceeded 256 μg/mL. CONCLUSION: We found a moderate rate of primary resistance to metronidazole. However, a high MIC (> 256 mg/L) which was found in 71% of the isolates is considerable. In the case of amoxicillin, an increased resistance rate of 20% is worrying. Resistance to clarithromycin and tetracycline is also emerging among the H. pylori strains in our region.

On June 16 and 17, 2007, the medical clinic of a prison in Isfahan, Iran received multiple reports of gastrointestinal illness among prisoners. A cross-sectional study was therefore undertaken to determine the extent, causative agent and possible source of the outbreak.A case-patient was defined and patient information was collected with a standardized questionnaire. Stool samples were collected from the patients and restaurant employees, and analyzed for the presence of enteric bacteria by routine bacteriological methods. Shigella isolates were identified and serotyped by commercially available antisera. The relationship between the strains was determined using antimicrobial drug resistance pattern analysis and enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR).Seven hundred one inmates experienced gastrointestinal illness and severe diarrhea. The attack rate was 14.02%. Rectal swabs and stool cultures recovered from patients tested positive for Shigella flexneri serotype 3a. All tested isolates had a similar antibiotic resistance and ERIC-PCR pattern. Our findings demonstrated that raw vegetables were more likely to be the causative agent of this outbreak.The results indicated that a single clone of S. flexneri was responsible for this outbreak. Although we could not trace the exact origin of the organism, the consumption of raw vegetables one day prior to the onset of illness was strongly associated with an increased risk of S. flexneri infection. This study emphasizes the need for accurate monitoring and surveillance of food and vegetables consumed in prisons.

Previous studies imply that IL-1 and IL-8 gene variations may play a crucial role in the genetic predisposition to different gastric disorders upon H. pylori infection.The aim of this study was to determine the potential association between the prevalence of certain polymorphic sites and the risk of gastric disorders in Iranian population.One hundred and forty three unrelated individuals with different gastric disorders and 374 normal individuals with no gastric disorders and with a negative serology test for H. pylori (control group) were studied for the association between IL-1ß (+3953 C/T) and IL-8 (-251 A/T) gene polymorphisms and H. pylori-mediated gastritis and gastric ulcer. An analysis of genotype frequency for these genes was performed using RFLP-PCR.Based on the data obtained from culture and pathologic findings, the patients were classified into three subpopulations: H. pylori(+) non-ulcerative gastritis(+), H. pylori(+) ulcerative gastritis(+) and H. pylori(-) non-ulcerative gastritis(+). A significantly higher frequency of TT genotype (p=0.02) in IL-1ß +3953 in H. pylori(+) ulcerative gastritis(+) was revealed compared to the control group. There were no significant differences among other subpopulations. No significant differences in allele and genotype frequencies of IL-8 (-251A/T) were found among the patients.The data suggest that TT genotype in IL-1ß +3953 may be a major contributing genetic risk factor for H. pylori induced gastric ulcer. Moreover, the role of other bacterial and host response factors, such as bacterial adherence peptides, host chemokines, and genes involved in gastric acid secretion, must be further investigated in different ethnic populations.

Escherichia coli are the most frequent pathogens in acute urinary infections. They are classified based on various types of O antigen. Escherichia coli strains that cause urinary tract infections possess several genes encoding urovirulent factors. To assay the relation of virulent factors of E coli in acute urinary infections, the serotypes and virulence factor genotypes were determined.We studied 96 E coli isolates from children with acute urinary infections. Four urovirulence determinants were analyzed by DNA colony hybridization, including the genes for type 1 fimbriae (pil), P fimbriae (pap), S fimbriae (sfa), hemolysin (hly), and cytotoxic necrotizing factor 1 (cnf1). O serotypes were also determined.The most frequently found virulence factor-encoding gene in the E coli strains studied was the gene for type 1 fimbriae (27.4%). The prevalence of pap, sfa, hly, and cnf1 were higher in serotypes causing pyelonephritis than cystitis. The most common type of O antigen was O1 (12.2%). There was a significant correlation between serotype and genotype in uropathogenic E coli.The high prevalence of O6 serotypes in children urinary tract infections and the high percentage of virulent genes in serotype O6 suggested a close relation between serotype and genotypes of uropathogen E coli.

The aim of this study was to determine the types and frequencies of VRE in terms of the existence of Van genes and to investigate the efficacy of newly introduced antibiotics. Totally 297 enterococcal strains were isolated from patients' specimens. Minimum inhibitory concentration of resistant isolates to vancomycin and tecoplanin were determined by E test method. Simultaneous detection of Van genes and species identification was preformed using multiplex PCR. Sensitivity patterns of VRE isolates to several antibiotics were determined by disk diffusion (Kirby-Bauer) method. One hundred and four (35%) of the isolates were VRE of which 12.5, 10.5 and 7% from urine, blood and stool samples were detected, respectively. Resistant isolates were sensitive to tigecycline and linezolid and resistant to ciprofloxacin and amikacin. The isolates which were resistant to ciprofloxacin, amikacin and gentamicin also showed cross-resistance to the other tested antibiotics. VanA is the predominant gene of Van-positive isolates in Iran. Meanwhile, the prevalence of Van-negative intermediate VRE in E. fecalis is markedly increased. These findings lend support to the hypothesis that due to frequent vancomycin administration in our clinics the acquisition of Van genes as well as selection of resistant mutant isolates could be facilitated. Rational prescription of vancomycin and wisely administration of newly introduced antibiotics like tigecycline and linezolid is warranted.

To evaluate the association of virulence genes CagA, VacA and UreAB of H. pylori with the development of different gastric disorders, polymerase chain reaction was performed on H. pylori organisms isolated from biopsy samples of stomach of patients with ulcerative disease and nonulcerative disease. The difference between the groups was statistically significant (p < 0.05) only for VacA gene. We detected 8 phenotypes, characterized as CagA(+)-VacA(-)-UreAB(+) (phe 1), CagA(-)-VacA(-)-UreAB(-) (phe 2), CagA(+)-VacA(+)-UreAB(-) (phe 3), CagA(+)-VacA(-)-UreAB(+) (phe 4), CagA(-)-VacA(+)-UreAB(+) (phe 5), CagA(+)-VacA(-)-UreAB(-) (phe 6), CagA(-)-VacA(+)-UreAB(-) (phe 7), CagA(-)VacA(-)-UreAB(+) (phe 8). The prevalence of phenotype 1 was significantly higher in the patients with UD than that in the patients with NUD (p < 0.05). These results suggest that in the population under our study, being infected by a H. pylori strain with the genotype CagA(+)-VacA(+)-UreAB(+) may be associated with an increased risk of acquiring an ulcer disease.