فهرست مطالب عزیز ژاپونی

Pseudomonas aeruginosa is one of the main etiological agents in burn infections which could be life threatening for the infected patients. The aim of the present study was to identify and track source of infections using two molecular typing methods. Seventy-four strains of P. aeruginosa were isolated from burn patients and hospital environment in Ghotbadden Burn Hospital, Shiraz, Iran. Isolates were typed by arbitrary primed-polymerase chain reaction (AP-PCR) and plasmid profiling. Similarity and clustering of the strains was assessed using NTSYS-PC software and photo Capt Mw program. Thirty eight plasmid profiles were obtained and classified them into: 2, 3and 5 clusters, based on 50%, 64.7% and 67.5% similarity on the plotted dendrogram, respectively. Drawn dendrogarm categorized AP-PCR products to 47 different types. Based on these results, a limited number of P. aeruginosa types are predominant in the hospitals which infect the burn patients. To control of the infections in patients with antibiotics, resistant isolates, strong disinfection of patients’ bathroom after scrubbing of patients wounds, should be implemented.

Dendritic cell (DC) is as a key cell in activation of immune response against microbes and disease. Therefore, the effect of recombinant exotoxin A of Pseudomonas aeruginosa on the maturity and the activation of DCs was evaluated in this study. Recombinant exotoxin A was produced from Pseudomonas aeruginosa DNA. MTT assay was used to evaluate the cytotoxicity of this protein on DCs. The expression of co-stimulatory molecules CD40, CD86, and MHCΠ was evaluated by flow cytometry. Moreover, the effect of this antigen (Ag) on T-cell proliferation was evaluated using Mixed Lymphocyte Reaction (MLR) assay and the secretion of IL-4 and IFN- γ. Secretion of IL-12 by DCs was measured with Enzyme-Linked Immunosorbent Assay (ELISA) method. The data were collected and analyzed with one way ANOVA test. Recombinant exotoxin A had no effect on DCs viability. In addition, expression of CD40, CD86, and MHCΠ did not change significantly compared to the negative control cells. Moreover, T-cells proliferation was decreased significantly at the concentration of 0.1µg/ml of this Ag. The secretion of IL-12 was increased by DCs, in contrast the secretion of IL-4 and IFN-γ in MLR supernatant did not decrease significantly. Exotoxin A decreases the proliferation of T-cells and also leads to a change in the pattern of cytokine secretion of immune cells.

Because of emerging multi-drug resistance (MDR) Pseudomonas aeruginosa strains, treatment of burn patients infected by this bacterium is difficult. The aim of this study was to detect antimicrobial profile and molecular epidemiology of metallo-beta-lactamase (MBL) producer strains. In this cross-sectional investigation 270 Pseudomonas aeruginosa isolates were collected from the burn patients. Carbapenem sresistance strains were detected by phenotypic E-test method. Susceptibility profiles of metallo-β-lactamase (MβL) enzyme producing isolates of this bacterium to 11 antimicrobial drug were determined by disc diffusion method according Clinical and Laboratory Standards Institute (CLSI) guidelines. The genetic correlations between isolates were determined by Pulsed-Field Gel Electrophoresis (PFGE) method. Among 270 P. aeruginosa isolates, 60 (22.2%) strains showed resistant to meropenem (MEM) and imipenem (IMI) and were considered as metallo-β-lactamase positive. All metallo-β-lactamase positive isolates were resistant to five tested antimcrobial while their sensitivities to the three best effective antibiotics including ciprofloxacin, amikacin and ceftazidime were 1.7%, 6.7 % and 23.3%, respectively. Majority of the isolates (71.6%) showed more than 80% similarity based on the drawn dendrogram. Our results showed, the tested antimicrobials are not safe to prescribe for burn patients. According PFGE pulsotypes, a limited number of P.aeruginosa types are common in the hospital burn unit which infect the patients hospitalized in this ward.

Cyclophosphamide is an alkylating agent that stops the replication of DNA، which is used to treat various types of cancer and some autoimmune disorders. This study was aimed at then evaluating the immunomodulating effect of cyclophosphamide (Cy) on the immune system of vaccinated and non-vaccinated mice. The study was performed on three groups of mice consisting of vaccinated، non-vaccinated and control groups. Vaccination was carried out by three separated courses of C. albicans injection intraperitoneally. Then، the vaccinated group received Cy on day zero and were challenged with lethal doses of C. albicans on days zero، one، 3، 6 and 12 post-Cy injection. Non-vaccinated group received Cy on day zero and similar to vaccinated ones were challenged with lethal doses of the organism. The control groups received just Cy on day zero and were sacrificed on days post-Cy injection. Then، the hemogram and the spleen and the renal tissues were studied microscopically and macroscopically. In the vaccinated group، an increase in survival time، the number of polymorphonuclear and the significant hyperplasia in the white pulp on days 6 and 12 post-Cy injection were noticed. In non-vaccinated ones، these factors had significant decrease on days 1 and 3. It is concluded that the hyperplasia in the white pulp of spleen and an increasing in peripheral polymorphonuclear due to the selective effects of Cy could effectively protect the animal against C. albicans infection.

Nosocomial infections caused by methicillin-resistant staphylococci (MRSA) poses a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus) including 200, 137 and 19 corresponding to MRSA, MSSA and intermediates strains, respectively were isolated from the hospitalized patients. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates to the other tested antibiotics were also determined. S.aureus with high frequencies were isolates from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were noticed. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the latter eight antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinics. To preserve effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.

Introduction & H. pylori is a human pathogen which infects the gastric mucosa and causes an inflammatory process leading to gastritis, ulceration and cancer. It is not clear what factors determine these divergent outcomes of infection. The aim of the present study was detecting the immunogenic proteins in H. pylori strains isolated from patients with different gastric diseases. Total proteins of 144 strains of H. pylori isolated from 3 groups of patients (gastric ulcer 37, gastritis 77 and gastric cancer 30) were separated by 1D-SDS-PAGE and then were blotted with the sera of their respective hosts. In SDS-PAGE the members of each group showed high correlation regarding to similarity in their patterns, resulting in considering them in the same cluster. The patterns of immunoblots differed from that of Commassie Brilliant Blue stained gels. Some of the protein bands in the SDS-PAGE were not recognized by blotting method. Only the bands of 106 and 45 kDa from H. pylori strains isolated from patients with GC were significantly recognized specifically with the sera of their respective patients and the band of 13 kDa was recognized specifically with the sera of nonulceric patients. With the exception of these bands, in the patterns of blotting of the sera from all patients no significant differences were observed. Using 1D blotting methods we could find 2 antigenic protein bands (106 and 45 kDa) for H. pylori strains isolated from cancerious patients and one (13 kDa) for the strains isolated from nonulceric patients which were specifically recognized with their respective host. Further studies have to be conducted to show if the antigens described here are of predictive value for certain clinical states.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The aim of this study was to determine the risk factors of nasal carriage of MRSA and its antibiotic susceptibility pattern among healthcare workers at Namazi Hospital (Shiraz-Iran) In a cross-sectional study from July to November 2006, nasal swabs were taken from 600 stratified randomly selected health care workers. The isolates were identified as S. aureus based on morphology, gram stains, catalase test, coauglase test and DNase Agar. To differentiate Methicillinsusceptible S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA), agar screen plate was used. All methicillin-resistant isolates were examined for mecA genes existence by PCR performance. The sensitivity patterns of S.aureus isolates were determined by disc diffusion and E-test method. Nasal screening identified 186 (31%) S. aureus carriers of whom, 154 ones (82.8%) were MSSA and 32 ones (17.2%) were MRSA._There was no significant association between related risk factors and gender, age, years of healthcare service and level of education. In the univariate analysis, a statistically significant difference was found only based on occupation (P=0.032) between carriers of MSSA and MRSA. In multivariate analysis(logistic regression), having nursing occupation (p=0.012, OR=3.6, 95%CI=1.3-9.7) was independently associated with MRSA carriage. All of the MRSA strains were sensitive to mupirocin. This study revealed that having nursing occupation is independently associated with MRSA carriage since all S.aureus isolates were susceptible to mupirocin, topical mupirocin could be used successfully to eradicate nasal staphylococcal colonization and carriers.

Introduction & Different studies show that the reasons for clinically diverse outcomes of infections caused by H. pylori may include host and environmental factors as well as differences in the prevalence or expression of bacterial virulence factors. The aim of this study was to study the distribution of different genotypes of major virulence factors cagA, vacA and ureAB among H. pylori strains isolated from patients with gastric ulcer (ulcerative disease) and patients with gastritis (non ulcerative disease). In this cross sectional study 65 H. pylori strains, 30 from patients with gastric ulcer and 35 from patients with non ulcerative gastritis disease were investigated by RFLP-PCR. The prevalence of vacA-positive strains in ulcerative patients was significantly more than that in non ulcerative patients (P<0.05). RFLP analysis revealed two different patterns for cagA gene. The prevalence of pattern β with three bands was significantly higher in both groups of patients. Enzymatic digestion resulted in a strictly homogeneous pattern for 83.33% of the vacA+ strains isolated from the patients with ulcer. This pattern was significantly associated with ulcerative status (P<0.05). ureAB polymorphism analysis revealed 10 distinguishable DNA banding patterns among them the pattern named ureAB 5a was the most prevalent (47.61%) in all isolates. No association between a specific DNA pattern and clinical disease was observed for cagA and ureAB (P>0.05). It seems that in the patients under our study the presence of cagA gene may not necessarily be a risk factor for ulcer disease, while a homologous genotype of vacA appears to be associated with an increase risk of ulcer development. Lastly, despite the existence of a high degree of genomic variability within ureAB, conserved DNA banding profiles are distributed in our areas.

It is not clear what factors determine divergent outcomes of infections caused by H.pylori. The aim of this study was to differentiate H. pylori strains isolated from the patients with different gastroduodenal pathologies by protein profiling. The protein profiles of different strains of H. pylori isolated from 3 groups of patients with ulcerative disease, nonulcerative gastritis and cancer disease were analyzed using 1D-SDS-PAGE. Based on the highly divergent protein patterns, the similarity of the strains inside each group was 75%, 76.47% and 78.57% for cancerous, ulcerative and no ulcerative groups, respectively, while about 30.76% of the protein bands were common in all strains isolated from three groups of the patients. Some of the observed bands were significantly specific for each group. We speculated that some H. pylori strains might be more associated with a specific disease than others, leading to the clustering of some, but not all, strains within each disease group. This study showed that protein profile can be a criterion used for discriminating of dominant states in different gastric clinical states. Specific and dominant proteins of different strains isolated from three groups of patients under the study could be welcome candidates for further exploration to be used both for laboratory tests, which analyze disease-specific H. pylori strains, and for diagnosis of different diseases and outcomes associated with this widespread bacterium.

Recent studies showed a possible relationship between infections caused by some of Helicobacter members and gallstones formation. The aim of this study was identification of Helicobacter members in gallstones from patients with biliary diseases. Gallstones and bile samples from 33 patients were subjected to rapid urease test, culture and Multiplex-PCR using primers based on 16s rRNA and isocitrate dehydrogenase genes to identify Helicobacter genus and H. pylori species genes, respectively. This PCR was also done on bile samples from 40 autopsied gallbladders with normal pathology (as a control group). In 18.1% of stones and 12.1% of bile samples, H. pylori DNA was detected using PCR. Rapid urease and cultures tests were negative for all samples. The genome of H. pylori was not detected in control group using PCR. H. pylori DNA was detected in gallstone, however, we are not sure of H. pylori viability in these samples. To clarify the clinical role of Helicobacter in gallbladder diseases, more investigations are needed to ascertain whether this microorganism is innocent bystander or active participant in gallstone formation.