فهرست مطالب

Jundishapur Journal of Microbiology
Volume:7 Issue: 10, Oct 2014

  • تاریخ انتشار: 1393/09/02
  • تعداد عناوین: 10
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  • Ramazan Mirzaei, Esmat Shahriary, Mazhar Iqbal Qureshi, Ataollah Rakhshkhorshid, Abdolali Khammary, Mahdi Mohammadi * Page 1
    Background
    Bio-aerosols are a potential hazard in hospitals and are mostly produced by hospital staff, patients and visitors. Bio-aerosols are solid or liquid particles pending in the air and they consist of aerosols accompanying micro-organisms or organic compounds of micro-organisms such as endotoxin, metabolite, toxin and other parts of organism. Those are a potential hazard in hospitals and are mostly produced by hospital staff, patients and visitors..
    Objectives
    This study aimed to determine the types and amount of bacterial contamination in operating rooms and emergency department of an educational hospital in Zahedan, South-East of Iran..
    Materials And Methods
    In this study, 72 samples were collected from three operating rooms and three rooms in the emergency department of an educational hospital during 2012. On the first day of every month, a sample was taken from each room during the morning shift; active sampling was done on plates consisting of blood agar and brain-heart infusion agar (BHI) for 10 minutes in the axis of a one-story Anderson impactor (flow rate 28.1 litter per minutes) and SIBATA air pump SIP 32-L and samples were then placed in a 35°C Incubator. Bacterial colonies were counted; warm coloring and differential tests were done and the data were analyzed using Mann-Whitney U and Kruskal-Wallis tests..
    Results
    Seventeen types of bacteria were detected including Staphylococcus, Micrococcus, Viridians, Pneumococcus, Escherichia coli, Streptococcus, Bacillus cereus, B. subtilis, Klebsiella, Pseudomonas, Diphtheroid, Citrobacter and Enterobacter. Quantitative bacterial results showed that the number of observed bacteria in the emergency department with an average of 103.88 ± 33.84 cfu/m³ was more than that of the surgery rooms with an average of 63.32 ± 32.94 cfu/m³. Furthermore, the highest average number of all counted colonies (106 ± 28.45 cfu/m³) was determined in autumn. In all samples, S. aureus and Micrococcus were the most detected bacteria..
    Conclusions
    The World Health Organization (WHO) has suggested relatively relaxed limits of 100 cfu/m3 for bacteria and 50 cfu/m3 for fungi in the hospital air. Therefore, quantitative and qualitative outcomes of this study demonstrate that contamination level and bacterial variety in surgery rooms and emergency departments is high and effective measures must be taken to control the possible health risks..
    Keywords: Operating Room, Hospital, Bioaerosol, Bacteria, Fungi, Indoor
  • Abolfazl Gholipour, Neda Soleimani, Dariush Shokri, Sina Mobasherizadeh, Mohammad Kardi, Azar Baradaran * Page 2
    Background
    Extended-spectrum beta-lactamases (ESBLs) are a group of enzymes that hydrolyze antibiotics, including those containing new cephalosporins, and they are found in a significant percentage of Escherichia coli and Klebsiella pneumoniae strains. With the widespread use of antibiotics, difficulties with infection therapy caused by drug resistant organisms, especially those that have acquired resistance to beta-lactams, such as broad-spectrum cephalosporins, have amplified the above-mentioned organisms..
    Objectives
    This study was conducted to characterize ESBLs among E. coli and K. pneumonia isolates by molecular and phenotypic methods..
    Materials And Methods
    Different strains of E. coli and K. pneumonia were collected from patients with urinary tract infections. The ESBL phenotype was determined by a double disk diffusion test (DDDT). In addition, polymerase chain reaction (PCR) analysis specific for β-lactamase genes of the TEM and SHV family was carried out. The PCR products were run on agarose and examined for DNA bands..
    Results
    A total of 245 E. coli and 55 K. pneumonia strains were isolated from different samples. In total, 128 of the 300 isolates were confirmed as potential ESBLs producers as follows: 107 (43.67%) E. coli and 21 (38.18%) K. pneumonia. ESBLs genes were found in 24 isolates (18.75%): 21 E. coli and 3 K. pneumonia isolates. The TEM gene was present in 13 (12.14%) E. coli strains, but it was not detected in K. pneumonia. In addition, the SHV gene was present in 8 (7.47%) E. coli and 3 (14.28%) K. pneumonia isolates. Five (4.67%) of the E. coli isolates harbored both TEM and SHV genes. All isolates (100%) were susceptible to imipenem. The lowest rates of resistance to other antibiotics were observed for; piperacillin-tazobactam (6.25%), amikacin (12.5%) and gentamicin (14.84%). The rates of resistance to other antibiotics were as follow: nitrofurantoin (16.4%), nalidixic acid (23.43), co-trimoxazole (25%), cefepime (32%), ciprofloxacin (55.46%), ampicillin (69.53%), ceftazidime (100%), and cefotaxime (100%)..
    Conclusions
    The results of this study indicate the widespread prevalence of ESBLs and multiple antibiotic resistance in E. coli and K. pneumoniae. Therefore, beta-lactam antibiotics and beta-lactamase inhibitors or carbapenems should be prescribed based on an antibacterial susceptibility test..
    Keywords: Phenotypic, Molecular, extended, spectrum ?, lactamase (ESBL), Escherichia coli, Klebsiella pneumonia
  • Katayun Aliakbarzade, Safar Farajnia *, Ashraf Karimi Nik, Farzaneh Zarei, Asghar Tanomand Page 3
    Background
    Acinetobacter baumannii is one of the major causes of nosocomial infections and is resistant to most available antibiotics. Aminoglycosides remain as drugs of choice for treatment of Acinetobacter infections yet resistance to aminoglycosides has increased in the recent years..
    Objectives
    The present study investigated the prevalence of genes encoding aminoglycoside-modifying enzymes in A. baumannii strains isolated from patients of Tabriz city, northwest of Iran..
    Materials And Methods
    A total of 103 Acinetobacter isolates were collected from Imam Reza Hospital of Tabriz University of medical sciences. Antimicrobial susceptibility patterns of the isolates to different antimicrobial agents including cephalosporins, gentamicin, amikacin, tobramycin, colistin and polymyxin, were evaluated by the disc diffusion method. The frequency of aminoglycoside modifying enzymes encoding genes aacC1, aphA6, aadA1 and aadB was analyzed by the PCR method..
    Results
    Antimicrobial susceptibility analysis showed that the highest resistance was towards beta−lactam antibiotics including cephalosporins whereas the highest sensitivity was observed towards colistin (77%) and polymyxin (84%). The resistance rate to aminoglycosides was 81%, 86% and 63% for amikacin, gentamicin and tobramycin, respectively. The PCR results showed that among the 103 A. baumannii isolates, 56 (65.11 %) were positive for aacC1, 52 (60.46 %) for aphA6, 24 (27.9 %) for aadA1 and 16 (18.6 %) for aadB resistant genes..
    Conclusions
    The results of this study indicated that the genes encoding aminoglycoside-modifying enzymes are prevalent in A. baumannii isolates in the study region, which highlighted the necessity of considering preventive measures to control dissemination of these resistance genes..
    Keywords: Acinetobacter Baumannii, Antimicrobial Agents, Aminoglycoside
  • Mehrdad Hajilooi, Pegah Lotfi, Farhad Seif, Ahad Bazmani, Mohammad Momeni, Ali Ravary, Mohammad Kazemi Arababadi, Ali Reza Khalilian * Page 4
    Background
    Several lines of evidence approve that innate and adaptive immunity play key roles in the defense against visceral leishmaniasis (VL). The polymorphism within the cytotoxic T lymphocyte antigen 4 (CTLA-4) gene alters its expression..
    Objectives
    The main aim of this study was to evaluate the polymorphism within the +49 position of the CTLA-4 gene of Iranian patients with VL in comparison with healthy controls..
    Materials And Methods
    In this cross-sectional study, 88 patients with clinical presentations of VL, who were seropositive for Leishmania (group 1), 86 patients without clinical presentations but seropositive (group 2), and 115 healthy controls (group 3) were assessed with respect to the CTLA-4 +49A/G polymorphism, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The anti-Leishmania antibody titration was evaluated using an immunofluorescence method..
    Results
    Our results indicated that both CTLA-4 +49A/G polymorphisms were significantly associated with VL..
    Conclusions
    According to the results, the polymorphisms within the +49 position of CTLA-4 can be associated with VL and may be considered as risk factors for the disease..
    Keywords: Visceral Leishmaniasis, CTLA, 4, Polymorphism
  • Majid Zarrin *, Neda Babadi Page 5
    Background
    Fungi have been extensively isolated and investigated from skin in various parts of the world. Determining the mycoflora of normal people is important when the role of skin is considered as a reservoir for microorganisms..
    Objectives
    The current study aimed to investigate the incidence of fungal flora on interdigital spaces of the human foot.. Patients and
    Methods
    Samples were collected from interdigital spaces of 865 girl students who lived in the dormitories of Ahvaz Jundishapur University of Medical Sciences. A part of the sample was digested with 20% KOH and screened by a light microscope for fungal elements. Another part of the sample was cultured on Sabouraud glucose agar (SGA) and SGA containing 0.05 mg/mL chloramphenicol and 0.5 mg/mL cycloheximide. The fungal colonies were identified based on morphological and microscopic characteristics and biochemical tests..
    Results
    In the current study, out of the 865 samples, 616 (71. 2%) were positive in direct examination or culture. Of these, 267 samples (30. 9%) were positive in direct examination. The most common fungal isolates in direct test were yeast (29. 4%), followed by conidia (0. 92%), melanised hypha (0. 35%) and non-septated hyphae (0. 23%). Trichophyton mentagrophytes was isolated in one of the specimens..
    Conclusions
    The present study demonstrated the incidence of fungal flora on interdigital spaces of human foot. The current study results showed that fungi can survive on surfaces of skin without showing the sign of infection.
    Keywords: Mycoflora, Interdigital Spaces, Foot
  • Mojtaba Moosavian, Saeed Shoja *, Roohangiz Nashibi, Nasim Ebrahimi, Mohammad Amin Tabatabaiefar, Soodabeh Rostami, Amir Peymani Page 6
    Introduction
    Recently Acinetobacter baumannii isolates have emerged as a problematic infectious agent that causes meningitis in neurosurgical patients. Colistin has been used successfully for the treatment of A. baumannii meningitis but colistin resistant isolates have been reported worldwide..
    Case Presentation
    Two isolates of A. baumannii were cultured during a five-day period from cerebrospinal fluid (CSF) samples of a 20-year-old man with a gunshot trauma in the abdomen, which had exited from his back. Antimicrobial susceptibility tests of isolates were performed. Multiplex PCR was performed for detection of blaOXA-23-like, blaOXA-24-like and blaOXA-58-like genes. Metallo-β-lactamase genes such as: blaVIM, blaIMP, blaSPM and blaNDM were sought by singleplex PCR. In order to evaluate the genetic relationship, two isolates were examined by the repetitive extragenic palindromic-polymerase chain reaction (REP_PCR) method..
    Conclusions
    E-test results showed that the isolates were sensitive to colistin and tigecycline with minimum inhibitory concentration of (MIC) 0.25 µg/mL and 1.5 µg/mL, respectively. Secondly the isolates were resistant to colistin with MIC > 256 µg/mL but remained sensitive to tigecycline with MIC 1.5 µg/mL. On the basis of the multiplex PCR, both of the isolates were positive for blaOXA-23-like. Other investigated genes such as blaOXA-24-like, blaOXA-58-like, blaVIM, blaIMP, blaSPM and blaNDM were negative. REP-PCR results showed that two isolates were derived from a single strain and both were the same. The results of our study revealed that the firs isolate of A. baumannii was colistin heteroresistant and was changed to completely resistant during therapy. Diagnosis and treatment of A. baumannii meningitis is very important and to avoid treatment failure we suggest that all A. baumannii isolates obtained from CSF should be evaluated properly for colistin heteroresistance..
    Keywords: Acinetobacter baumannii, Meningitis, Colistin, Neurosurgery
  • Sedighe Rashno Taee, Behzad Khansarinejad, Hamid Abtahi, Mohammad Najafimosleh, Ehsanollah Ghaznavi Rad * Page 7
    Background

    Pseudomonas aeruginosa is an opportunistic pathogen that infects patients with cystic fibrosis, burning wounds, ophthalmic traumas and immunodeficiency..

    Objectives

    The aim of the present study was to compare the efficiency of newly designed primer sets with some previously published primers for PCR detection of exoA, oprL and algD genes from P. aeruginosa..

    Materials And Methods

    A total of 150 clinical specimens were inoculated into the routine and selective culture media for P. aeruginosa isolation. Specific primers were designed by bioinformatics analysis for detection of the virulence genes determinants, exoA, oprL and algD. The sequences of these three genes were obtained from NCBI and multiple alignments were performed to find the conserved sequences of each gene to design the primers. Multiple alignment and primer design steps were carried out by the AlleleID software, version 7.0..

    Results

    Microbiological culture methods resulted 70 P. aeruginosa strains isolated from 70 of the 150 clinical specimens. The results of the PCR assay using the newly designed exoA, oprL and algD primer sets were positive in 68, 70 and 69 clinical samples which represent 97.2%, 100% and 98% sensitivity for each primer set, respectively. The PCR results using previously published exoA, oprL and algD primer sets were positive only in 57, 49 and 28 specimens that correspond to 81.5%, 70% and 40% sensitivity, respectively..

    Conclusions

    The results of the present study showed that in comparison with previously published primer sets, P. aeruginosa infection can be diagnosed with higher sensitivity and specificity by the conventional PCR assay using the newly designed primers. It was also shown that the results of the PCR assay on clinical samples of severe infections became positive much earlier than the results of conventional culture method..

    Keywords: Pseudomonas aeruginosa, Clinical Samples, Detection, PCR
  • Ramin Niknam, Mehrdad Seddigh, Mohammad Reza Fattahi, Amirreza Dehghanian, Laleh Mahmoudi * Page 8
    Background
    The prevalence rate of gastric infections caused by Helicobacter pylori is different in between as well as within various countries, including Iran..
    Objectives
    This study was aimed to evaluate the prevalence of H. pylori in Iranian adult patients with dyspepsia..Patients and
    Methods
    A total of 548 patients with dyspepsia referred to Namazi Hospital, a referral center for gastrointestinal diseases in Shiraz, south of Iran, were evaluated in a cross-sectional study. The diagnosis of dyspepsia was based on clinical findings. Upper gastrointestinal endoscopy was performed for all the patients and two antral biopsies were taken from all the included ones. The patients were categorized based on the endoscopic findings, to four groups: 1-normal, 2-abnormal nonulcerative, 3-ulcerative, and 4-combination of 2 and 3. Two positive test results (Gram staining, rapid urease test, and culture) was considered as a positive-definite H. pylori infection for each patient..
    Results
    From the 548 included patients (238 males and 310 females), H. pylori was detected in 170 (31.2%). The mean age was 40.38 ± 15.39 years old. H. pylori infection was detected in 26.1% of male and 34.8% of female patients and its prevalence increased with age. Eighty three (48.8%) patients were positive for H. pylori infection, of which, 12.4% had normal and 36.4% had abnormal nonulcerative endoscopic findings; 17.1% of patients were ulcerative and 34.1% had ulcer with or without concurrent abnormality..
    Conclusions
    Findings from this study showed a lower prevalence of H. pylori infection than other studies and its prevalence increased with age. There was no association between sex and infection. The most common endoscopic abnormality in H. pylori-positive patients was ulcerative lesion..
    Keywords: Helicobacter pylori, Dyspepsia, Prevalence, Endoscopy
  • Mohammad Najafi Mosleh, Marzieh Gharibi *, Mohammad Yousef Alikhani, Massoud Saidijam, Giti Kalantarian Page 9
    Background
    β-lactams resistant Streptococcus pneumoniae are an emerging problem throughout the world. Several resistance mechanisms have been reported, including expression of drug-destroying enzymes such as β-lactamases, altered drug targets such as conformational changes in PBPs, decreased bacterial permeability, and increased drug efflux..
    Objectives
    The present study aimed to determine the relationship between the results of polymerase chain reaction identification of the Pbp1a, Pbp2b and Pbp2x genes (penicillin-binding proteins) and susceptibilities of β-lactam antibiotics against S. pneumoniae..
    Materials And Methods
    Fifty five isolates of S. pneumoniae were obtained from clinical samples with antimicrobial tests. The susceptibilities of isolates to benzylpenicillin, imipenem, oxacillin, ceftazidime were determined. The resistance genotype was determined by the polymerase chain reaction with primers designed for the PBP genes..
    Results
    The number of S. pneumoniae isolates resistant to benzylpenicillin, imipenem, oxacillin and ceftazidime were 94.5%, 100%, 100%, and 21.8%, respectively. Analysis of mutation in the genes for pbp showed that 85% of isolates had mutations in pbp2x, pbp2b and pbp1a. Susceptibility to benzylpenicillin was decreased once the number of mutated pbp genes in S. pneumonia increased. According to the results of this study, S. pneumoniae isolates showed reduced susceptibility due to accumulation of resistance genes..
    Conclusions
    We suggest that studies should be performed to evaluate changes in Minimum Inhibitory Concentration (MIC) values as well as genetic mutations in order to determine prevalence of S. pneumoniae resistance against antimicrobial agents..
    Keywords: S. pneumoniae, PCR, lytA, Pbp1a, Pbp2b, Pbp2x
  • Zohreh Aminzadeh, Davood Yadegarynia, Alireza Fatemi *, Elham Tahmasebian Dehkordi, Saeed Azad Armaki Page 10
    Background
    New data indicates that vancomycin may be less effective against methicillin-resistant Staphylococcus aureus (MRSA) infections with minimum inhibition concentration (MIC) within a sensitive range..
    Objectives
    The aim of this study was to determine the distribution of the vancomycin MIC between MRSA strains and observe the difference in mortality between patients, while the influence of changes in MIC on the efficacy of vancomycin was also examined..Patients and
    Methods
    A routine date-based study was conducted on 41 MRSA isolates in a hospital in Tehran, Iran. The isolates were assessed for MIC by using the E-test method, and results were categorized into three groups: A (MIC < 1.5 μg/mL), B (1.5 ≤ MIC < 2 μg/mL) and C (MIC ≥ 2 μg/mL) MRSA..
    Results
    Group A was the most common group, followed by groups C and B. Although there was no statistically significant difference between patients’ mortality with the MIC group, the mortality rate of group A was higher than C and B..
    Conclusions
    Regarding Clinical and Laboratory Standards Institute (CLSI) definition for vancomycin susceptibility (MIC < 2 μg/mL), it seems that vancomycin may not be considered as the best antibiotic in order to treat heteroresistant vancomycin intermediate S. aureus (hVISA) and vancomycin sensitive S. aureus (VSSA) infections, and a new breakpoint for vancomycin and alternative antibiotics should be considered..
    Keywords: Vancomycin, Minimum Inhibitory Concentration, Methicillin Resistant, Staphylococcus aureus, Mortality