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Background and Objective: High-level gentamicin resistance (HLGR: MIC ≥ 500 µg/ml) in Enterococci is mediated by aminoglycoside modifying enzymes which is mainly encoded by aac(6′)-Ie-aph(2′′)-Ia gene. The aim of this study was to evaluate the frequency of aac(6′)-Ie-aph(2′′)-Ia gene in clinical isolates of Enterococcus facium and Enterococcus faecalis collected from hospitals in northwest of Iran. Materials and methods: In the present study a total of 111 enterococcus isolates were collected from 4 hospitals during a two year period (July 2009-August 2011). Bacterial identification and species determination were carried out by standard biochemical tests. Antimicrobial susceptibility was evaluated by Kirby Bauer disc diffusion method. MICs were determined by agar dilution method. The frequency of aac(6′)Ie-aph(2″)Ia gene in the isolates was determined by PCR. The carriage of resistance gene on Tn5281 transposon was identified by long PCR and dot-blot hybridization methods. Results: Antibiotic susceptibility tests revealed that the highest resistance was against streptomycin (74.77%) and erythromycin (67.58%) whereas the highest susceptibility was observed to vancomycin (81.1%). 36 isolates (32.43%) were identified as HLGR, 34(94.44%) of them had resistant gene in their genome. Long PCR studies revealed that 88 % of HLGR clinical isolates harboured Tn5281. The aac(6′)Ie-aph(2″)Ia resistance gene was present on Tn5281 transposon in all 32 isolates according to dot blot hybridization test. Conclusion: The results of this study indicated that aac(6′)Ie-aph(2″)Ia resistance gene is highly prevalent in gentamicin resistant isolates. Carriage of aac(6′)Ie-aph(2″)Ia resistance gene on Tn5281 transposable element suggests possible contribution of this transposone on dissemination of resistance gene among enterococcus isolates.

Background: Identifying Mycobacterium tuberculosis (MTB) transmission type is a key step in the control of this disease. Aim: This study aimed to determine the path and transmission type of MTB and the insertion sequence IS6110 band number and verify their relationship to demographic and clinical risk factors. Subjects and Methods: In this cross‑sectional study, 64 MTB patients from three border provinces of Iran were selected after full clinical history and physical evaluation design. The drug susceptibility testing was carried out using the standard proportion technique on sputum samples. Isolates tested with restriction fragment length polymorphism technique used IS6110. Results: Recent transmission of disease was 33/50 (66%) based on clustering rate. The IS6110 band number had a significant relationship with drug resistance detected in proportion method tested by univariate linear regression (P

Many organisms have developed an internal clock to cope with the daily and seasonal cycles in the environment. In mammals, suprachiasmatic nuclei (SCN) of the hypothalamus control circadian rhythms in behavior and physiology. Evidence links the proper function of circadian clock to mental and physical health. Aging disturbs the accurate function of the SCN and impairs many rhythms such as sleep-wake cycle. Hence improvement of clock function can aid healthy aging. In chapters 3 and 4 I show the ensemble output of the SCN neuronal network is more robust than individual cells__ output suggesting a compensatory role of the network in aging. Seasonal changes affect the physiology and reproduction success of many organisms. The SCN encodes for day-length by adjusting the pattern of its electrical activity rhythm.. In chapters 5 and 6 I reveal that plasticity in interneuronal and cell-intrinsic functions in the SCN helps the organism to adjust to yearly natural changes in photoperiod. These results imply that extensive artificial light in modern society may alter neurotransmitters action in the SCN. A better understanding of SCN network function and cellular properties facilitate alleviation of modern life-related diseases caused by circadian disturbances and aging.

Purpose: Recently discovered Anabaena variabilis phenylalanine ammonia lyase (AvPAL) proved to be a good candidate for enzyme replacement therapy of phenylketonuria. Outstanding stability properties of a mutant version of this enzyme, produced already in our laboratory, have led us to the idea of culture conditions optimization for soluble expression of this therapeutically valuable enzyme in E. coli. Methods: In the present study, the gene encoding mutant version of AvPAL was cloned into the pET28a expression vector. Different concentrations of IPTG, induction period, growth temperature, shaking speed, as well as different types of culture media were examined with respect to the amount of recombinant protein produced and specific activity of the enzyme. Results: Based upon our findings, maximum amount of active mutant enzyme was attained by addition of 0.5 mM IPTG at 150 rpm to the TB culture media. The yield of active enzyme at cluture tempreature of 25 °C and induction period of 18 hour was the highest. Conclusion: The results of this study indicated that the yield of mutant AvPAL production in E. coli can be affected mainly by culture temperature and inducer concentration., Advanced Pharmaceutical Bulletin; eISSN 2251-7308

Meningitis is one of the hazardous and life threatening infections and is associated with mortality and morbidity. The aim of this study was to determine etiological agents of childhood bacterial meningitis. The culture, Gram staining, agglutination and PCR assays were used to examine CSF specimens from 277 patients with presumed bacterial meningitis for the occurrence of 4 most common infectious agents consist of N. meningitis, H. influnsae, S. pneumoniae and S. agalactiae between 2008 and 2009 at different wards of the Children Hospital of Tabriz. The mean age of patients was 35±2 (Mean±SEM) month, (minimum 11 days maximum14 years), of all cases 59.6% male and 40.4% female. Overall the diagnosis was confirmed with a CSF culture in 11/277 (3.97%), by agglutination test in 14/277 (5.05%). The isolated bacteria included S. pneumoniae 5 cases, H. influnsae 2 cases, N. meningitis 3 cases and P. aeroginusae 1 case. A positive PCR assay allowed us to diagnose bacterial meningitis in 19 patients (6.8%). In the present study, we found PCR to be a useful and sensitive method for the detection of bacterial DNA in the CSF samples from suspected meningitis patients. Furthermore, to maximize management of meningitis cases, a combination of culture and PCR is necessary.

In this study, 290 non-Escherichia coli Enterobacteriasea that were isolated from environmental and clinical specimen, were sent to the laboratory for examination with routine microbiological tests foridentification of isolates. After identification, non-E. coli isolates were inspected by PCR for existence of penicillin G acylase (PGA) gene. Then, a PGA positive strain (Shigella boydii) from clinical specimenswas selected for further analysis. First, DNA was isolated and PCR reactions were conducted using primers based on conserved region of PGA genes. The PCR reaction resulted in amplification of a specific product with expected length. The PCR product was cloned in pGEM-T Easy vector.Sequencing revealed that the gene, composed of encodes a polypeptide of 846 amino acid residues. Analysis of obtained sequence against databases showed the highest homology (about 96%) with the PGA gene reported from S. boydii.

Objectives: Metallo-β-lactamases (MBLs) producing Acinetobacter baumannii has become a growing therapeutic concern. The aims of this study were to assess the antimicrobial susceptibility pattern of A. baumannii isolates and to determine the prevalence of MBL genes among carbapenem resistant isolates.[for full text, please go to the a.m. URL], 10. Kongress für Infektionskrankheiten und Tropenmedizin (KIT 2010)

BACKGROUND AND OBJECTIVE: Acinetobacter (A.) baumannii is a gram-negative non-fermentative coccobacilli with increasing relevance in a variety of hospital-acquired infections. The aim of this study was to determine the frequency of bla-OXA-2 and bla-OXA-10 resistance genes and class I Integron among Acinetobacter baumannii strains isolated from patients referred to Imam Reza hospital of Tabriz city, Iran.METHODS: This cross-sectional descriptive study was carried out on 100 Acinetobacter baumannii isolated from patients referred to Imam Reza hospital of Tabriz, Iran in 2009-2010. The isolates were identified using standard biochemical and microbiological tests. ESBL production was determined in isolates by Combined Disc test. The presence of bla-OXA-10, bla-OXA-2 and INT-1 genes in clinical isolates was investigated by PCR technique. FINDINGS: The results of antimicrobial sensitivity tests revealed that the highest resistance was against cefixime (100%), ceftizoxime (100%) and ticaracilin (100%), whereas the highest susceptibility was observed for polymyxin B (84%), colistin (77%) and rifampin (73%). Combined Disc Test showed that 60% of isolated were ESBL producer among them 7 cases (11.6%) were positive for bla-OXA-2 and 5 cases (8.3%) for bla-OXA-10 genes. Screening for INT-1 genes demonstrated that 73% of isolates were positive for Int-1 insertion sequence.CONCLUSION: The results of this study showed the presence of OXA-2 and OXA-10 type ESBLs and class I integron genes among drug resistant Acinetobacter strains that reminding the necessity of preventive measures for inhibiting dissemination of these resistant isolates.

Objective(s): Drug resistant Acinetobacter baumannii have emerged as a major problem in many hospitals and intensive care units. Various types of extended spectrum beta-lactamases (ESBLs) are responsible for resistance to beta- lactam antibiotics in different parts of the world. The objective of this study was to determine the prevalence of integron class1 (INT 1) and ESBL types PER-1, PER-2 and VEB-1 among A. baumannii strains isolated from Tabriz, North-West of Iran. Material and Methods: A total of 100 A. baumannii isolates collected from different clinical samples were included in the study. Antimicrobial susceptibility profiles were determined using the Kirby Bauer disk diffusion method. Production of ESBL was investigated by testing resistance against ceftazidime, cefotaxime, ceftriaxone and verified by Double Disk Synergy Test. DNA was extracted from the isolates and the frequency of INT 1 and ESBL types PER-1, PER-2 and VEB-1 were determined by PCR using specific primers. Results: Among 100 A. baumannii isolates screened, 80 isolates were multidrug-resistant and 70 isolates were positive for ESBL production. PCR screening revealed that 74 % of the isolates contained class 1 integron, 51% were positive for PER-1 gene, 10% positive for VEB1 whereas none of the isolates were positive for PER2 type gene. Conclusion: This is the first report of ESBL types VEB and PER in A. baumannii from North West of Iran. The results of this study demonstrated high prevalence of PER-1 and VEB-1 type ESBLs among A. baumannii isolates in the study region and reminded the necessity of appropriate infection control strategy to prevent further spread of infection by these organisms.

Penicillin G acylase (PGA) is one of the most important enzymes in the pharmaceutical industry. It is utilized in the process for production of semi-synthetic penicillins. Several different penicillin acylases with various characteristic have been isolated from different bacteria and identification of bacterial isolates harboring PGA enzyme with higher industrial compatibilities is of high interest. The aim of this study is to screen for PGA producing Escherichia coli isolates as well as the cloning and recombinant expression of PGA for high level enzyme production. Bacteria isolated from environmental and clinical samples were identified by standard microbiological tests and then E. coli isolates were subjected toDNA extraction and PCR screening using primers designed on conserved region of PGA genes. The PCR product from a positive isolate were cloned and subjected to sequencing. The gene encoding for full length PGA was expressed in E. coli under the T7 promoter. PCR screening identified several PGA positive E. coli. One of the positive isolates was cloned in pGEM -T easy vector. Sequencing of the cloned gene revealed that the gene encoding Penicillin G acylase from this wild E. coli isolate containsan open reading frame of 2538 nucleotide encoding 846 amino acids. Analysis of the sequencing results showed that the PGA gene is highly conserved among E. coli strains. Recombinant expression of PGA from wild isolate in E. coli BL 21 resulted in a high level expression of recombinant PGA which appeared as a dense band in SDS-PAGE analysis of induced culture.

Genome-wide association studies in Asian population for the first time identified common variants in the KCNQ1 gene to be associated with type 2 diabetes in Japanese populations, recently. This result has been replied in some other East Asian population but, still now, there is no any report about this subject in Iranian population. The aim of this study was to investigate the frequency of KCNQ1 variants in type 2 diabetes in East Azerbaijan population, northwest of Iran. A total of 75 T2D and 90 normal East Azerbaijan subjects were entered the study. A demographic date was recorded for all subjects. Genomic DNA was extracted from the whole blood, and the KCNQ1 single nucleotide polymorphisms (SNPs) rs2237892 were genotyped with PCR-RFLP technique. The results of the study indicated an increased level of FBS and HbA1C among T2D cases (P