Tehran University Medical Journal

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In a bacteriological study on 230 biopsies of patients suffering gastrointestinal disorders in Imam Khomeyni Hospital, 88 patients were selected as case and another 88 as control groups. Case group was treated by triple (Bismuth subcitrate, Metronidazole and Tetracycline) drugs for a period of 14 days. The latter treated by nonbismuth regiment eg. Amoxicillin and Ranitidine mainly. All of the patients were examined bacteriologically by biopsies in 1, 6 & 12 months after treatment. Obtaind data revealed that the Bismuth composed regiment was more effective than non-bismuth composing ones. In fact, bacterial eradication was approved in 89.8% of case group without recurrence of symptoms among them at least for entire year. Conversely, eradication occulted just in 23.5% of control group, frequent recruidescen Cl of pipriculear observed among them within one year.

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Helicobacter pylori (H.Pylori) is the most common human infection in the world. This agent has a strong role in pathogenesis of chronic gastritis and peptic ulcer. Therefore introducing of simple and cost effective tests are important for diagnosis of H.Pylori infections. ELISA has been considered as an alternative test compare with biopsy, histological staining, culture and urease test in diagnosis of H.Pylori infection. In this investigation, 111 patients referred to GI endoscopy department of Imam Khomeini Hospitals for U.G.I problems which were evaluated for H.Pylori infection. Culture and histological staining (GIMSA and H & E) were used as a gold standard test compare with ELISA-IgG and urease test. Sensitivity and specificity for ELISA were 90%, 93% respectively. This report suggests that ELISA is a cost effect and valid test in diagnosis of H.Pylori infection

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Helicobacter pylori (H.pylori) is the most common human infection in the world. This agent has a strong role in pathogenesis of chronic gastritis and peptic ulcers. Therefore introducing of simple and cost effective and non invasive tests are important for diagnosis of H.pylori infections. In this study 215 patient suffering from different gastrointestinal disorders referred to GI endoscopy department of Dr. Ali Shariati Hospital were selected as case and another 50 as control group, which were evaluated for H.pylori infection. Direct smear (staining with Giemsa) and urease tests were used as gold standard tests compared with IFA-IgG and culture. Sensitivity and specificity and accuracy for IFA were 94%, 86% and 90%, respectively. Absorption with campylobacter jejoni did not change the level of IgG against H.pylori. Negativity of urease test dose not show the eradication or absence of bacteria, but shows the low number of bacteria in biopsy materials. This report suggest that IFA is an advantageous, sensitive and reliable test in diagnosis of H.pylori infection.

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Background: Staphylococci as a micro-organism, has the most importance to cause nosocomial infections, particularly in patients with indwelling catheters or other medical devices. Unfortunately 90% of Staphylococci isolated from the nosocomial infections are resistant to methicillin, and methicillin resistance strains are also resistant to a wide range of antimicrobial drugs, therefore detecting of these strains are valuable to eradicate the infection elements. Despite guidelines published by the national committee for clinical laboratory standards (NCCLS) for testing of susceptibility to methicillin for Staphylococci, the phenotypic method for detecting methicillin resistance remains controversial. Therefore, the genetic assays have been used to detect antimicrobial susceptibility of Staphylococci to methicillin.
Materials and Methods: Resistance to methicillin is coded by mec A gene in staphylococcus, and this gen must be detected in genetic assays. In this study 155 clinical staphylococcal isolates (70 coagulase- negative staphylococcus and 85 coagulase- Positive staphylococci) were evaluated for susceptibility to methicillin by using disk diffusion method.
ResuIts&Conclusion: Methicillin resistance was shown in 62 coagulase- negative staphylococcus (72.9%) and 27 coagulas positive staphylococcus (38.6%) but 63 coagulase negative Staphylococci (74%) and 28 coagulase positive isolates with mec a gene associated resistance were detected by PCR method. The results of this test were compared to the results for mec A gene detection by PCR test as a gold standard. The sensitivity, specifity and accuracy of the disk diffusion test for coagulase-negative staphylococcus were 96.8%, 95.45% and 96.47% and for coagulase positive staphylococci were 98.43%, 95.45% and 98.32% respectively.

 

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Background and Aim: Helicobacter pylori is the etiologic agent of chronic –active gastritis, gastroduodenal ulcers in humans, and a co-factor in the occurrence of gastric cancer and mucosa-associated lymphoid tumors, Adhesion of H.pylori to the gastric mucosa is a critical and also initial step in the pathogenesis of the disease. Bacterial adhesion inhibitory agents provide a novel pharmacologic approach to the management of infectious diseases.    

Materials and Methods: 22 H. pylori strains, isolated from the antral biopsies of 49 patients with dyspepsia, gastritis, gastric ulcer, duodenal ulcer,…were assayed by ELISA (UPR)to investigate the diversity of attachment to 7 mamalian cell lines.

Results: The concentration of H.pylori and cell suspention ,the condition and temperature, can alter the attachment rate.Best bacterial concentration was equal to 1 Mc farland,and for cell suspension was 5*10 cells/ml.90 minutes in 37C incubation period result in maximum attachment. H.pylori can attach to all 7 cell lines, there are no significant differences between 22 H.pylori strains in attachment to cells. The attachment pattern of H.pylori to the cells showed significant reduction respectly from HepII, HeLa, SW742, AGS,HT29/219, HT29 to Caco-2.Maximum attachment were seen to HepII, HeLa and SW742 cells, and among these HepII was the best cells for this purpose.

Conclusion: Our studies suggest that Hep II, HeLa and SW742 cells could serve as a suitable in-vitro model for the study of H.pylori adhesions, attachment, inhibition of attachment and detachment assays and among these Hep II cell is prefer recommended.

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Background: The incidence of ESBL producing species have been steadily increased in recent years, resulting in limitation of infection control issues and therapeutic options.The purpose of this study was to evaluate prevalence of Enterobacteriaceae and also assess epidemiology ESBL producing strains isolated from patients admitted in ICUs.
Methods: A total of one hundred fifty isolates were collected from urine, sputum, blood, wound and other clinical samples from patient admitted in ICU and then were identified by biochemical tests .All of the samples were screened by DAD method according to The NCCLS Guideline. The species that met NCCLS screening criteria was further tested for Clavulanic Acid effect by confirmatory method.
Results: A total of one hundred fifty isolates,133(89.3%) were found to be resistant at least on of the indicators cephalosporin tested according to NCCLS Guideline. 121(80.6%) of the isolates were resistant to all the indicators tested .89(59.3) isolateds were confirmed as ESBL producers. The number of isolates ESBL producing was as follow: Klebsiella pneumoniae 33 (76.74%), E.coli 20 (60.60%), Enterobacter cloacae 8 (47.05%), Citrobacter diversus 6 (54.54%), Enterobacter aerogenes 7 (53.84%), Citrobacter freundii 4 (40%), Klebsiella oxytoca 6 (62.5%), Proteus mirabilis 4 (50%), Serratia marcescens 2 (40%), Proteus Volgaris 0%.All of the isolates sensitive to imipenem.
Conclusion: The present study shows high prevalence of ESBL producing Enterobacteriaceae from patients admitted in ICU .The increased rate of these species in most cases due to the administration of inadequate and irrational antimicrobial therapy .To overcome this problem, it needs to develop new antimicrobial agents, limiting the Unnecessary Use of antimicrobial and increasing compliance with infection control issues.

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Background: The resistance of Pseudomonas aeruginosa strains to broad spectrum cephalosporins may be mediated by extended spectrum b-lactamases (ESBLs). These enzymes are encoded by different genes located either on chromosome or plasmids. In this study, we determined the antimicrobial resistance patterns of P. aeruginosa isolates and screened for ESBL production.

Methods: After isolation from burn patients in Tehran Hospital, identification of P. aeruginosa isolates were assessed using biochemical tests. We then performed disk agar diffusion (DAD) according to CLSI guidelines to determine the pattern of antimicrobial resistance. The frequency of ESBLs and prevalence of the OXA-10 and PER-1 genes were determined with combined disk and polymerase chain reaction (PCR) methods, respectively.

Results: One hundred strains of P. aeruginosa were isolated. The resistance of these strains to cephpodoxime, aztreonam, ciprofloxacin, ofloxacin, ceftazidime, cefepime, imipenem, meropenem, cefotaxime, levofloxacin, piperacilin- tazobactam and ceftriaxon was 100%, 90%, 83%, 92%, 85%, 88%, 63%, 66%, 98%, 89%, 70% and 91%, respectively. Of these, 40 strains (40%) were ESBL positive, 29 strains (29%) were OXA-10 positive and 18 strains (18%) were PER-1 positive.

Conclusion: Our results confirm the need for proper antimicrobial therapy in burn hospitals, considering the resistance pattern and frequency of strains producing ESBLs and the presence of the OXA-10 and PER-1 genes. Since an increase in the prevalence of ESBL in P. aeruginosa strains might lead to the transfer of these ESBL genes to other gram-negative bacteria, we recommend the use of appropriate drugs, especially cephalosporins, in burn hospitals.

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 Comparing Intensity Elicited Maximum Reflex Amplitude Between Noise Induced Hearing Loss & Acoustic Trauma at 1kHZ, Contralaterally, and Investigate Relationship Between Amplitude and Hearing Impairment

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Background: Pseudomonas aeruginosa is an important opportunistic pathogen causes clinical infections among burn patients. Metallo-β-lactamases (MBLs) are important mechanisms of Carbapenem (drug of choice) resistance among Pseudomonas aeruginosa isolates. The aims of this study were to determine the antibiotic susceptibility pattern and to detect the prevalence of MBLs among Pseudomonas aeruginosa
Methods: Initially, the antibiotic resistance patterns of 170 clinical strains isolated from burn patients in Motahari Hospital in Tehran, Iran were determined by Kirby-Bauer disc diffusion method. All of the clinical isolates using two phenotypic and genotypic methods.  Pseudomonas aeruginosa isolates resistant to Imipenem were screened for production of MBL by E test with Imipenem / Imipenem plus EDTA (E test MBL). PCR assay was performed for detection of blaVIM genes.
Results: Based on the study results, the percentage of resistance was as below: Imipenem (10 μg) 52.9%, Amikacin (30 μg) 81.7%, Carbenicilin (100 μg) 74.7%, Polymixine B (300 unit) 10%, Ticarcilin (75 μg) 84.7%, Tobramycin (10 μg) 88.2%, Colisitin (10 μg) 34.1, Colisitin (25 μg) 28.3%. Of 90 Carbapenem resistant isolates, 10(11/1%) isolates were positive by E test, all were sensitive to Colisitin and Polymixine B. All of the Imipenem resistant Pseudomonas aeruginosa isolates were examined by PCR for the presence of the blaVIM genes. All MBL-producing isolates carried blaVIM-1 genes.
Conclusion: Considering the high prevalence and clinical importance of MBL-producing isolates, rapid identification of them and use of the appropriate infection control measures are necessary to prevent further spread of infections by these organisms.