فهرست مطالب

  • Volume:8 Issue: 7, 2015
  • تاریخ انتشار: 1394/05/12
  • تعداد عناوین: 20
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  • Bahman Mirzaei, Zakaria Bameri, Ryhane Babaei, Fereshteh Shahcheraghi* Page 1
    Background
    Bordetella pertussis, as a causative agent of whooping cough, due to the annual rise y of infection cases, failure of prophylaxis and treatment by macrolides, is considered as the new concern in the health care system.
    Objectives
    The main objective of this study was the determination of single nucleotide polymorphisms (SNPs) at domain V, as the main binding site for macrolides, following the identification of high level macrolides resistant B. pertussis.
    Materials And Methods
    Following the identification of 11 recovered B. pertussis isolates, from a total of 1084 nasopharyngeal swabs, by using the biochemical and molecular methods, the activities of erythromycin, azithromycin and clarithromycin antibiotics against the recovered isolates were examined. Subsequently, A-G transition mutations in domain V were analyzed by molecular techniques, such as Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and sequencing.
    Results
    After susceptibility testing, one strain was detected as a high level macrolide resistant B. pertussis (Erythromycin = 128 μg/mL, Clarithromycin > 256 μg/mL). After sequencing and PCR-RFLP methods, transition mutations in positions 2047 and 2058 of the mentioned domain were not observed.
    Conclusions
    Although previous studies have shown that A-G transition mutations in 23 SrRNA gene (domain V) are the main reason for the occurrence of high level macrolides resistance in B. pertussis, however, the mentioned single nucleotide polymorphisms (SNPs) have not been detected in our resistant strain. This is the first report of high level macrolide resistant B. pertussis, without SNPs in domain V, in Iran.
    Keywords: Drug Resistance, Minimum Inhibitory Concentration, Macrolides, Bordetella pertussis, Mutation
  • Mohammad Pooideh, Ismail Jabbarzadeh, Reza Ranjbar, Mahnaz Saifi* Page 2
    Background
    Tuberculosis (TB) is a widespread infectious disease. Today, TB has created a public health crisis in the world. Genotyping of Mycobacterium tuberculosis isolates is useful for surveying the dynamics of TB infection, identifying new outbreaks, and preventing the disease. Different molecular methods for clustering of M. tuberculosis isolates have been used.
    Objectives
    During a one year study of genotyping, 100 M. tuberculosis isolates from patients referred to Pasteur Institute of Iran were collected and their genotyping was accomplished using pulsed field gel electrophoresis (PFGE) method.
    Materials And Methods
    Identification of all M. tuberculosis isolates was accomplished using standard biochemical and species-specific polymerase chain reaction (PCR) methods. Antibiotic susceptibility tests were performed using proportional method. After preparing PFGE plaques for each isolate of M. tuberculosis, XbaI restriction enzyme was applied for genome digestion. Finally, the digested DNA fragments were separated on 1% agarose gel and analyzed with GelCompar II software.
    Results
    Genotyping of the studied isolates in comparison with the molecular weight marker revealed two common types; pulsotype A with 71 isolates and one multidrug resistant mycobacterium (MDR) case, and pulsotype B including 29 isolates and three MDR cases. No correlation between the antibiotypes and pulsotypes was observed.
    Conclusions
    Molecular epidemiology studies of infectious diseases have been useful when bacterial isolates have been clustered in a period of time and in different geographical regions with variable antibiotic resistance patterns. In spite of high geographical differences and different antibiotic resistant patterns, low genetic diversity among the studied TB isolates may refer to the low rate of mutations in XbaI restriction sites in the mycobacterial genome. We also identified three MDR isolates in low-incidence pulsotype B, which could be disseminated and is highly important to consider in TB surveillance programs to prevent the spread of MDR-TB isolates in the population.
    Keywords: Mycobacterium tuberculosis, Pulsed Field Gel Electrophoresis, Molecular Epidemiology
  • Nasimeh Fard, Mousavi, Ghasem Mosayebi, Alireza Amouzandeh, Nobaveh, Alireza Japouni, Nejad, Ehsanollah Ghaznavi, Rad * Page 3
    Background
    Nasal carriage of Staphylococcus aureus plays an important role in the pathogenesis of staphylococcal infections. Anterior nasal region is a primary origin of S. aureus. In longitudinal studies, three types of S. aureus nasal carriers can be distinguished: persistent carriers, intermittent or transient carriers, and noncarriers.
    Objectives
    This study was designed to determine the dynamic of S. aureus nasal carriage in healthy carriers of central Iran.Patients and
    Methods
    A total of 813 healthy adults were subjected to this cross-sectional study from November 2011 to January 2012 in Arak University of Medical Sciences. Two anterior nasal swabs were taken with a week interval from each participant. All the isolates were identified as S. aureus phenotypically by standard laboratory methods. The isolates were reconfirmed by amplification of sa442 gene as the identification marker. All the isolates were screened for the presence of the PVL (Panton-Valentine leukocidin) virulence genes and arginine catabolic mobile element (ACME-arc).
    Results
    Among the 813 subjects screened, 83 (10.2%) were persistent carriers, 86 (10.6%) were transient carriers and 644 (79.2%) cases were found as noncarriers. A total of 169 (20.8%) participants had colonized S. aureus. The frequency of ACME–arc A and PVL genes in S. aureus strains were 17% and 20%, respectively.
    Conclusions
    Carriage of PVL-positive S. aureus is common in this region, even in the low frequency of MRSA colonization. The detection of ACME-arcA gene in S. aureus isolates is a public-health concern and demands continued surveillance and close monitoring.
    Keywords: Staphylococcus aureus, Panton, Valentine Leukocidin, Dynamics Population
  • Fateh Rahimi, Majid Bouzari* Page 4
    Background
    Methicillin-resistant Staphylococcus aureus (MRSA) is known as a common pathogen in nosocomial and community-acquired infections. Sewage acts as an environmental reservoir and may have a significant role in development and dissemination of antibiotic resistance.
    Objectives
    This study was undertaken to determine the epidemiological relatedness between the MRSA isolated from sewage and human infections.
    Materials And Methods
    Samples were collected from a referral hospital and also a sewage treatment plant in Tehran, Iran, during 2010. All the MRSA isolates were identified at the species level and typed using Phene plate (PhP) system and SCCmec typing. Antibiotic susceptibility tests were also performed.
    Results
    Of the 1142 isolates, 200 MRSA strains from the sewage (n = 100) and the clinic (n = 100) were isolated. Distinct PhP types, consisting of 16 common types and 13 single types, and also 3 different staphylococcal cassette chromosome mec (SCCmec) types (III, IVa and IVc) were found amongst the MRSA isolated from the two different sources. The results of antibiotic susceptibility testing showed an increased resistance to penicillin, ciprofloxacin, erythromycin, clindamycin and tetracycline. In addition, none of the isolates showed resistance to vancomycin, quinupristin -dalfopristin and linezolid.
    Conclusions
    The presence of common PhP types and also SCCmec type III, as an indicator for hospital strains, among the isolates, may indicate an epidemiological link between clinical and sewage MRSA isolates in Tehran.
    Keywords: thicillin, Resistant Staphylococcus aureus, Sewage, Hospital, Staphylococcal Cassette Chromosome mec, Typing
  • Estibaliz Sansinenea *, Francisco Salazar, Melanie Ramirez, Aurelio Ortiz Page 5
    Background
    Bacillus thuringiensis is the most successful biological control agent used in agriculture, forestry and mosquito control. However, the insecticidal activity of the B. thuringiensis formulation is not very stable and rapidly loses its biological activity under field conditions, due to the ultraviolet radiation in sunlight. Melanin is known to absorb radiation therefore photo protection of B. thuringiensis based on melanin has been extensively studied.
    Objectives
    The aim of this study was to find a wild type strain of naturally melanin-producing B. thuringiensis to avoid any mutation or manipulation that can affect the Cry protein content.
    Materials And Methods
    Bacillus thuringiensis strains were isolated from soils of different States of Mexico and pigment extraction was followed by lowering the pH to 2 using 1N HCl. Pigment was characterized by some chemical tests based on its solubility, bleaching by H2O2 and flocculation with FeCl3, and using an Infrared (IR) spectrum. Ultraviolet (UV) irradiation experiment was performed to probe the melanin efficacy.
    Results
    ELI52 strain of B. thuringiensis was confirmed to naturally produce melanin. The Cry protein analysis suggested that ELI52 is probably a B. thuringiensis subsp. israelensis strain with toxic activity against the Diptera order of insects. Ultra Violet protection efficacy of melanin was probed counting total viable colonies after UV radiation and comparing the results with the non-producing melanin strain L-DOPA (L-3, 4-dihydroxyphenylalanine) was also detected in the culture. ELI52 strain showed an antagonistic effect over some common bacteria from the environment.
    Conclusions
    ELI52 wild-type strain of B. thuringiensis is a good bio-insecticide that produces melanin with UV-resistance that is probably toxic against the Diptera order of insects and can inhibit the growth of other environmental bacteria.
    Keywords: Biological Control Agents, Melanin, Ultraviolet Rays, Bacillus thuringiensis
  • Abbas Bahador, Reza Raoo?an, Zahra Farshadzadeh, Leyli Beitollahi, Azad Khaledi, Sara Rahimi, Masoumeh Mokhtaran, Ali Mehrabi Tavana, Davood Esmaeili * Page 6
    Background
    Multidrug resistant strains of Acinetobacter baumannii (MDR-AB) have emerged as alarming nosocomial pathogens among patients with burning.
    Objectives
    The current study aimed to determine the susceptibility of A. baumannii species, carbapenems resistance patterns, and their association with ISAba1 and ISAba4 elements upstream of the blaOXA-like genes, and the distribution of international clone (IC) of A. baumannii isolates among patients with burning in Tehran, Iran.
    Materials And Methods
    In the current study, 62 A. baumannii species isolates from patients with burning in Tehran, Iran, in 2012 were evaluated for the antimicrobial susceptibility, genetic relationships, ICs, carbapenemase encoding genes, and insertion elements ISAba upstream of blaOXA-like genes.
    Results
    The highest rates of susceptibility were observed with colistin (88.7%) and tigecycline (82.2%). The extensively drug-resistance and pan drug-resistance were observed in 37.1% and 8.1% of the isolates, respectively. About 98.3% of 17 genotypes categorized into three distinct clusters. Thirty-six of the 62 isolates (58%) belonged to the IC II lineage. The most prevalent acquired OXA-type carbapenemase was blaOXA-23-like (62.9%). ISAba1 and ISAba4 were detected upstream of blaOXA-23-like genes in 45.1% and 12.9% of isolates, respectively. In 32.2% of all isolates, ISAba1 laid upstream of blaOXA-51-like genes. The PCR results were negative for carbapenemase genes of Ambler class A and B, except blaVIM-2. (1.6%).
    Conclusions
    It was the first study that attempted to detect the insertion elements ISAba and IC lineages in MDR-AB species isolated from patients with burning in Iran.
    Keywords: rug Resistance, beta, Lactamases, Molecular Epidemiology, Carbapenemase, IS elements, Acinetobacter baumannii
  • Mohammad Taghi Akhi, Reza Ghotaslou, Samad Beheshtirouy, Mohammad Asgharzadeh, Tahereh Pirzadeh, Babak Asghari, Naser Alizadeh, Ali Toloue Ostadgavahi, Vida Sorayaei Somesaraei, Mohammad Yousef Memar* Page 7
    Background
    Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity.
    Objectives
    This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates.
    Materials And Methods
    One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods.
    Results
    A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem.
    Conclusions
    Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics.
    Keywords: Surgical Site Infections, Antibiotic Susceptibility Pattern, Polymicrobial Infection, Minimal Inhibitory Concentration
  • Alisha Akya*, Afsaneh Salimi, Bizhan Nomanpour, Kamal Ahmadi Page 8
    Background
    Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections. The emergence and dissemination of metallo-beta-lactamases (MBLs) has contributed to the high rate of resistance among P. aeruginosa isolates.
    Objectives
    The purpose of this study was to describe the prevalence and the clonal dissemination of MBL- producing P. aeruginosa isolates collected from major hospitals in Kermanshah.
    Materials And Methods
    Antibiotic susceptibility testing was performed using the minimal inhibitory concentrations. The MBLs were investigated using the Double-Disk Synergy Test (DDST) and Polymerase Chain Reaction. Molecular typing was performed by Pulsed-Field Gel Electrophoresis (PFGE).
    Results
    Of the 60 P. aeruginosa isolates included in this study, 30 (50%) were resistant to Gentamicin, 38 (63.3%) to Piperacillin, 42 (70%) to Ceftazidime, and 45 (75%) to Cefepime. Twenty-nine (48.3%) isolates were MBL producers in the DDST test. Five (8.3%) isolates were positive for the VIM gene. PFGE analysis among the MBL producers revealed 12 distinct clonal patterns.
    Conclusions
    The inter- and intra-hospital dissemination of resistant clones is a matter of concern and is an indicator of the level of the improvement and surveillance of standard hygiene, particularly disinfection and hand washing before and after contact with patients. Given the emergence of MBL-producing strains, surveillance has become an important procedure to control the transmission of resistant strains.
    Keywords: Pseudomonas aeruginosa, Metallo, Beta, Lactamase, Clonal Dissemination, Molecular Typing
  • Hamideh Zakeri, Tahereh Shokohi *, Hamid Badali, Saba Mayahi, Mojtaba Didehdar Page 9
    Background
    The high degree of phenotypic similarity among Trichophyton species makes their identification difficult.
    Objectives
    The current study aims to establish the use of rolling circle amplification (RCA) based on internal transcribed spacer ribosomal DNA (ITS rDNA) as a powerful, simple, and rapid procedure for distinguishing closely related organisms, and specifically to identify Trichophyton species, which cause human and animal disorders.
    Materials And Methods
    A total of sixty-one isolates belonging to three species of Trichophyton were identified to the species level based on microscopic and macroscopic examinations and their ITS rDNA regions were sequenced. Three specific circular oligonucleotide probes targeting the ITS1 and ITS2 regions were designed to differentiate Trichophyton rubrum, T. mentagrophytes, and T. tonsurans.
    Results
    Of the 61 putative Trichophyton clinical isolates, 52 were identified to the species level. The most common species was T. mentagrophytes var. interdigitale (31 isolates), followed by T. rubrum (11 isolates), T. tonsurans (9 isolates), and T. violaceum (1 isolates); moreover, 9 isolates were identified as non-Trichophyton species. The RCA method correctly identified four Trichophyton species and was 100% specific for each species. Neither cross-reaction between the examined species of Trichophyton nor false positive or false negative results were observed.
    Conclusions
    Species identification of Trichophyton is crucially important for epidemiological and phylogenetic purposes and for genotype delineation. RCA based on ITS polymorphisms can be used to generate identification barcodes and as an alternative to DNA sequencing; it is a very fast, specific, and economical tool for species identification.
    Keywords: Identification, Trichophyton, Oligonucleotide Probes, Rolling Circle Amplification (RCA), DNA, Ribosomal
  • Akram Hoseinabadi, Iraj Rasooli*, Mojtaba Taran Page 10
    Background
    Biodegradable polyesters are candidates for the development of environmental friendly plastics. Poly-β-hydroxybutyrate (PHB) is a type of polyester from the hydroxyalkanoates family, synthesized by bacteria as an intracellular material and accumulated as granules in the cytoplasm.
    Objectives
    The aim of this study was to isolate Poly β-hydroxybutyrate over producing bacteria and optimize the production medium.
    Materials And Methods
    A variety of PHB-accumulating bacterial strains were isolated from Kermanshah oil refinery sludge in Iran. Poly-β-hydroxybutyrate-producing bacterial strains were confirmed by the gas chromatography method. The strain with the highest rate of PHB production was selected. Use of sugar cane molasses, a by-product of the sugar refinery industry, was investigated for the production of PHB. Plackett-Burman statistical method was employed to obtain factors in cell growth and PHB production. Optimization by the Response Surface Method (RSM) was done via two carbon sources, glucose and molasses.
    Results
    In the present study, 21 of 63 strains isolated from the refinery oil sludge produced PHB, seven of which were over producers. Poly-β-hydroxybutyrate production was analyzed by Sudan Black B staining, spectrophotometric and gas chromatography (GC) methods. The strain with the highest rate of PHB production was used to optimize the culture medium. Fifteen factors were analyzed in PHB production by the Plackett-Burman method to find the most effective factors. Five important factors were optimized by RSM. Molasses were used as a cheap source of carbon. The maximum PHB obtained from molasses was 6.62 g/L. The phenotypic and 16S rRNA biotyping tests led to the identification of the isolate as Bacillus coagulans.
    Conclusions
    The results suggest that B. coagulans is a good candidate for the fermentative production of PHB.
    Keywords: β hydroxybutyrate, Beta Hydroxybutyrate, Fermentation, Biodegradation, Plastics
  • Sadaf Asaei, Mazyar Ziyaeyan *, Mahsa Moeini, Marzieh Jamalidoust, Mohammad Amin Behzadi Page 11
    Background
    Enterically-transmitted acute viral hepatitis is caused predominantly by hepatitis A virus (HAV) and hepatitis E virus (HEV). The prevalence of HEV and HAV infections varies in different geographical regions.
    Objectives
    This study was conducted to determine the prevalence of HEV and HAV infections among Iranian healthy individuals in southern Iran.Patients and
    Methods
    Totally, 1030 samples were collected from healthy subjects in schools, those referred to tertiary outpatient clinics and health centers in Shiraz between November 2011 and May 2012. Their ages ranged between six months and 95 years. The presence of total anti-HAV and anti-HEV immunoglobulin M (IgM) in plasma was assessed by ELISA.
    Results
    The results showed that 66.2% and 0.6% of the general population in this area were positive for total anti-HAV and IgM antibodies by ELISA, respectively. As seen, 13.4% and 0.9% were positive for total anti-HEV and IgM antibodies, respectively. The difference in total anti-HAV and anti-HEV antibodies was significant among the age groups (P < 0.001).
    Conclusions
    This study showed that the prevalence rates of HAV and HEV antibodies were positively correlated with age. The results demonstrated that the infection with these two viruses in the region was high and some high-risk individuals including females at child-bearing age were more susceptible. HAV vaccination could be recommended for antibody-negative adults.
    Keywords: Seroepidemiological Study_Iran_Hepatitis E Virus_Hepatitis A Virus
  • Ulku Karaman_Nilgun Daldal_Ali Ozer_Ozgur Enginyurt * Omer Erturk Page 12
    Background
    Cyclospora species are rare among other Coccidia parasites and can cause recurrent gastroenteritis. Cyclospora spp. can infect reptiles, insects, rodents, and mammals.
    Objectives
    The present study aimed to determine the epidemiology of Cyclospora spp. in Malatya province and its neighboring provinces.Patients and
    Methods
    Totally, 2281 stool samples taken from patients with digestive system complaints who referred to the polyclinics affiliated with Inonu University, Faculty of Medicine in Malatya Province and its neighboring provinces, in 2006, and whose stool specimens were submitted to the parasitology department were examined. A questionnaire was developed to determine the epidemiology of Cyclospora spp. in the patients as the dependent variable of the study. All the participants signed an informed written consent. The samples were coated with Entellan™ after staining via acid-fast staining and were examined on an immersion microscope objective. The data are presented as mean, standard deviation, or number/percentage. The chi-square test was used for the statistical analyses. Statistically, a P value < 0.05 was accepted as meaningful.
    Results
    The stool samples were examined via direct microscopic examination and acid-fast staining. Positivity was determined in 129 (5.7%) cases. In the overall assessment of the patients with respect to general body itching, rectal itching, allergy, immunosuppression plus cancer, shortness of breath, ulcerative colitis, diarrhea, abdominal pain, salivation, constipation, nausea, vomiting, growth retardation, and anemia, there was no significant relationship. However, in the statistical evaluations among the positive cases, the difference was found to be significant.
    Conclusions
    The study was conducted in Malatya Province, but patients from the neighboring provinces were also included in the evaluation during the study. Of all the positive cases, 5.6% were those from Malatya Province and its surrounding areas. Additionally, Cyclospora spp. were observed among the patients referring to the polyclinics with digestive system complaints in 8.1% of those from the Adiyaman province and in 6.9% of those from the Kahramanmaraş region. The incidence of Cyclospora cayetanensis may be higher in these regions if an epidemiological study is performed. Consequently, we suggest that Cyclospora spp. be investigated in digestive system disorders, especially in immunosuppressed patients.
    Keywords: Cyclospora, Digestive System, Epidemiology
  • Mohammad Taghi Akhi *, Saeid Bidar Asl, Tahereh Pirzadeh, Behruz Naghili, Fatemeh Yeganeh, Yousef Memar, Yalda Mohammadzadeh Page 13
    Background
    Clostridium perfringens, a Gram-positive, anaerobic bacterium that produces at least 16 virulence factors including 12 toxins (α-ν), enterotoxin, hemolysin and neuraminidase, can create variable pathogenic condition, ranging from a food poisoning to life-threatening myonecrosis. Among C. perfringens strains, resistance to the drug choices such as penicillin as well as to alternatives of penicillin like metronidazole and clindamycin has also been observed.
    Objectives
    The aim of this study was to determine the resistance of isolated toxigenic and non-toxigenic C. perfringens strains against common antimicrobial agents.
    Materials And Methods
    In this descriptive study, a total of 136 stool specimens were collected. At first, cooked meat medium enrichment method was performed on samples at 45°C. Thereafter, a loopful of the enriched culture was transferred to blood agar and incubated anaerobically at 37°C for 24-72 hours. Colonies with double zone of hemolysis were identified by different biochemical tests such as phospholipase C (lecithinase) test, indole and urease production. The Minimum Inhibitory Concentration (MIC) for common antibiotics was determined by Etests (Epsilometer) and duplex Polymerase Chain Reaction (PCR) reaction was performed with specific primers for amplification of cpe (426 bp) and plc (283 bp) Genes.
    Results
    Of 136 stool samples including diarrhea [48] and non-diarrhea [88] ones, 83 (61.02%) C. perfringens were cultured. Of these 83, 79 C. perfringens isolates showed the alpha-toxin (phospholipase C) production gene by PCR. Respectively, 3 (9.09%) and 2 (4.34%) cpe genes were present in diarrhea and non-diarrhea samples. Of 79 isolates of C. perfringens, 34 (43.03%) cases showed no resistance, 18 (22.78%) had one resistance and 27 (34.17%) isolates had multiple resistance to imipenem, metronidazole, ceftriaxone, clindamycin, chloramphenicol, and penicillin.
    Conclusions
    Periodic evaluation of antimicrobial susceptibility for C. perfringens should be performed. Harboring of enterotoxigenic C. perfringens in individuals not necessarily results in diarrhea.
    Keywords: Clostridium perfringens, Antibiotic Resistance, Genes
  • Esra Ersoy Omeroglu* Page 14
    Background
    There are 4 different genera (i.e. Vibrio, Aliivibrio, Photobacterium, and Shewanella) in the new classification of bioluminescent bacteria. The mechanism of bioluminescence has yet to be fully elucidated. Therefore, the determination of physiological and genetic characteristics of bioluminescent bacteria isolated from different sources is very important. Pulsed-Field Gel Electrophoresis (PFGE) has the highest discriminatory power among the different molecular typing methods for the investigation of the clonal relationships between bacteria. For the PFGE analysis of bioluminescent bacteria, the NotI-HF™ is the method of choice among the restriction enzymes.
    Objectives
    The present study aimed to determine genetic relatedness via PFGE in 41 bioluminescent bacteria (belonging to 10 different species) isolated and identified from various marine sources.
    Materials And Methods
    Different bioluminescent bacteria (i.e. Vibrio gigantis, V. azureus, V. harveyi, V. lentus, V. crassostreae, V. orientalis, Aliivibrio logei, A. fischeri, Shewanella woodyi, and Photobacterium kishitanii) were analyzed by PFGE using the NotI-HF™ restriction enzyme. The whole DNA of the strains embedded into the agarose plugs was digested with enzyme at 37°C for 30 minutes. CHEF-Mapper PFGE system was used for electrophoresis and band profile of the strains for the NotI-HF™ restriction enzyme were analyzed by Bio-Profil-1D++ software (Vilber Lourmat) at 10% homology coefficient.
    Results
    Although all experiments were performed three times, four of forty-one bioluminescent strains (V. gigantis E-16, H-16 and S3W46 strains and A. fischeri E-4 strain) could not be typed by PFGE technique with NotI-HF™ enzyme. While only two strains (V. crassostreae H-12 and H-19 strains) were exhibiting same band pattern profiles (100% genome homology), thirty-six different PFGE band patterns were obtained. Pattern homologies changed between 66% - 92%, 73% - 83% and 49% - 100% for V. gigantis, V. harveyi and other strains, respectively.
    Conclusions
    The obtained results revealed that there has been a high rate of genetic diversity in bioluminescent strains isolated from Gulf of Izmir and V. lentus and V. crassostreae strains could be also bioluminescent for the first report. At the same time, PFGE analysis of bioluminescent bacteria including four different genera and ten different species were shown for the first time by this study. It is considered that data acquired by this study will contribute evolution and mechanism of bioluminescence to further works to be done.
    Keywords: Pulsed, Field Gel Electrophoresis, Bioluminescent, Aliivibrio, Shewanella, Vibrio, Photobacterium
  • Muhammad Sohail, Mohsin Khurshid*, Hafiz Ghulam Murtaza Saleem, Hasnain Javed, Abdul Arif Khan Page 15
    Background
    Urinary tract infection (UTI) is deemed the most prevalent infectious disease in that it has now touched the overall incidence of 18/1000 persons per year in the general population.
    Objectives
    This study sought to determine the characteristics of isolates from patients with UTI and their susceptibility to commonly used antibiotics in Punjab, Pakistan.Patients and
    Methods
    Totally, 1429 urine samples were analyzed from UTI patients for the isolation of uropathogens at Chughtai’s Lahore Lab, Lahore, Pakistan, during a period of 14 months. The antimicrobial susceptibility test was performed via the disc diffusion method for the isolates obtained from 392 (26%) positive cultures.
    Results
    The highest percentage (67%) of isolates was from females in comparison to males (33%). The frequency of Escherichia coli was the highest (62%) in culture-positive urine samples, followed by E. faecalis (15%), Candida (14%), Pseudomonas (6%), Klebsiella spp. (1%), Proteus (1%), and Staphylococcus aureus (1%). E. coli was highly resistant to antimicrobial drugs, viz. cephalexin (95%), cephradine (95%), pipemidic acid (92%), amikacin (91%), and nalidixic acid (91%). Most of the routine β-lactam antibiotics like amoxicillin/clavulanic acid, ampicillin, and aztreonam were also ineffective against E. coli, with resistance rates of 84%, 84%, and 72%, correspondingly. This pathogen showed maximum susceptibility (97%) against three drugs, namely imipenem, meropenem, and cefoperazone. Piperacillin and fosfomycin also provided significant results against E. coli with respective susceptibility rates of 96% and 90%.
    Conclusions
    Our results showed that broad-spectrum antibiotics such as imipenem, meropenem, fosfomycin, cefoperazone/sulbactam, and vancomycin would be the first line and the most effective drugs for the empirical treatment of urinary tract pathogens due to their higher resistance rates against other drugs like cephalexin, cephradine, ciprofloxacin, levofloxacin, and norfloxacin.
    Keywords: Urinary Tract Infections, Escherichia coli, Antimicrobial Drugs
  • Jinyang Zhang, Qinqin Han, Yuzhu Song, Qiang Chen, Xueshan Xia* Page 16
    Background
    Rabies virus (RABV) is one of the old deadly zoonotic viruses. It attacks the central nervous system and causes acute encephalitis in humans and animals. Host factors are known to be essential for virus infection and replication in cells. The identification of the key host factors required for RABV infection may provide important information on RABV replication and may provide new potential targets for RABV drug discovery.
    Objectives
    This study aimed to investigate the change in the subcellular distribution and expression of the host protein Prefoldin subunit 1 (PFDN1) in RABV-infected cells and the viral expression of plasmids in the transfected cells.
    Materials And Methods
    Mouse Neuro-2a (N2a) cells were infected by RABV or transfected with the plasmids of the nucleoprotein (N) and/or phosphoprotein (P) gene of RABV. The subcellular distribution of PFDN1 was analyzed by confocal microscopy, and the transcription levels of PFDN1 in the N and/or P gene of the RABV-transfected or RABV-infected N2a cells were assessed via real-time quantitative polymerase chain reaction.
    Results
    Confocal microscopy showed that PFDN1 was colocalized with the N protein of RABV in the infected N2a cells and was mainly recruited to the characteristic Negri-Body-Like (NBL) structures in the cytoplasm, as well as the cotransfection of the N and P genes of RABV. The transcription of PFDN1 in the RABV-infected N2a cells was upregulated, whereas the transfection of the N and/or P genes did not result in the upregulation of PFDN1.
    Conclusions
    The results of this work demonstrated that the subcellular distribution of PFDN1 was altered in the RABV-infected N2a cells and colocalized with the N protein of RABV in the NBL structures.
    Keywords: Prefoldin, Redistribution, Rabies Virus
  • Shahin Najar Peerayeh, Afsaneh Karmostaji* Page 17
    Background
    Acinetobacter baumannii has emerged as an important nosocomial pathogen. Hospital outbreaks of extensively drug resistant (XDR) A. baumannii are a great concern.
    Objectives
    Aims of this study were to characterize the resistance determinants and genetic relatedness of (XDR) A. baumannii isolates in hospitals in Tehran, Iran.
    Materials And Methods
    During a three-year study, clinical isolates of A. baumannii were collected from two hospitals in Tehran, Iran. Susceptibility testing to antibiotics was performed by disk diffusion method and XDR A. baumannii isolates were identified. Genes’ encoding for carbapenemase production and integrons were identified by PCR. MICs of imipenem and meropenem were determined by agar dilution. Multiple locus variable-number tandem repeat analysis (MLVA) typing was used to determine genetic relationships of XDR isolates.
    Results
    Using PCR for amplification of blaOXA-51, 93.9% (123.131) of isolates were identified as A. baumannii and 24.4% (30.123) were XDR. These isolates were resistant to gentamicin, ciprofloxacin, amikacin, cotrimoxazole, cefepime, cefotaxime, aztreonam and ceftazidime. Thirty percent of the isolates were resistant to tigecycline. All isolates were susceptible to colistin and polymyxin-B, while 93.3% (28.30) possessed blaOXA-23-like and 6.7% (2.30) possessed blaOXA-24-like. All isolates possessed insertion sequence (ISAba1) in the upstream region of the OXA-23-like gene. Almost 96.7% (29.30) of the isolates were positive for class I integron and 43.3% (13.30) for class II. These isolates were also positive for class I. Class III integron was not detected. MLVA typing of XDR isolates showed seven clonally complexes and 16 singletons.
    Conclusions
    The population structure of the A. baumannii isolates in our hospitals was genetically diverse. A significant association between XDR pattern and presence of class 1 integron (P < 0.001) was found indicating that many antibiotic resistance determinants are involved in development of XDR strains.
    Keywords: Extensively Drug, Resistant, Integrons, Oxacillinase, Acinetobacter baumannii
  • Iraj Sedighi, Mohammad Reza Arabestani, Ali Rahimbakhsh, Zahra Karimitabar, Mohammad Yousef Alikhani* Page 18
    Background
    Urinary tract infection (UTI) is one of the most common childhood bacterial infections and Escherichia coli is the major pathogen. Producing β-lactamase enzymes are the most common mechanism of bacterial resistance.
    Objectives
    This study aimed to determine the prevalence of Extended-Spectrum β-Lactamases (ESBLs) and Quinolone Resistance (qnr) genes in E. coli strains isolated from UTIs.
    Materials And Methods
    In this study, a total of 120 isolates of E. coli from urinary tract infections of the children were collected at Besat Hospital in Hamadan, Iran, from October 2010 to October 2011. The bacterial isolates were identified by standard biochemical methods. Antimicrobial susceptibilities were determined by disk diffusion method, and ESBLs-producing was confirmed phenotypically using the double-disk synergy (DDS) test. The presence and identification of ESBLs and qnr genes were determined by Polymerase Chain Reaction (PCR).
    Results
    The highest sensitivity was seen to imipenem (96.7%), amikacin (92.5%), nitrofurantoin (93.3%), ofloxacin (81.7%), gentamicin norfloxacin (70.8%), and ciprofloxacin (79.2%). In contrast, the highest rate of resistance was seen to co-trimoxazole (77%) and nalidixic acid (40.9%). The results showed that 6 (2.18%) and 4 (1.12%) isolates of ESBL-producing E. coli were positive with respect to having qnrB and qnrS genes, respectively. No isolates was found to have qnrA.
    Conclusions
    CTX-M was the most prevalent ESBL genotype in uropathogenic E. coli (UPEC) isolated from UTI. In addition, a high frequency of qnr genes among ESBL-producing E. coli was identified in this study. In order to avoid treatment failures, we recommend using phenotypic and molecular methods to diagnose these enzymes and qnr genes.
    Keywords: Quinolones, Antibiotic Resistance, Escherichia coli
  • Hadis Arabi, Iraj Pakzad *, Ayat Nasrollahi, Hasan Hosainzadegan, Farid Azizi Jalilian, Morovvat Taherikalani, Naser Samadi, Allireza Monadi Sefidan Page 19
    Background
    Extensive use of cotrimoxazole has been associated with increasing level of Escherichia coli resistance.
    Objectives
    In the current study, we focused on assessing the prevalence of E. coli resistance to cotrimoxazole and frequency of its associated genes.
    Materials And Methods
    One-hundred and forty-four E. coli isolates were identified during March 2007 to April 2012 at Ilam hospitals and Milad (Tehran) hospital. Antibiotic susceptibility for screening of resistance isolates was done by the Kirby-Bauer method. The sul1, sul2, sul3, dfrA1, dfrA5, int1, blaTEM, blaSHV and CTX-M genes were detected by polymerase chain reaction (PCR) amplification. Plasmid curing was done for identifying correlations between resistance genes and plasmids.
    Results
    Amongst the 144 E. coli isolates, seventy-two (50%) Extended Spectrum Beta Lactamase (ESBL)-producing and seventy-two (50%) non-ESBL-producing E. coli isolates were identified; eighty-seven isolates (60.41%) were resistant to cotrimoxazole. Frequencies of sul1, sul2 and sul3, were 81% (116 isolates), 67% (96 isolates) and 2.29% (three isolates), respectively. Furthermore, 50.57% (72 isolates) had sul1 and sul2, 2.29% (3 isolates) contained sul2 and sul3, and 2.29% (three isolates) contained sul1, sul2 and sul3 genes, simultaneously. Thirty-four (39.1%) of the isolates had the dfrA1 gene. Five (5.7%) of the isolates had the dfrA5 gene. Sixty-eight (78.2%) strains contained the int1 gene. Furthermore, dfrA1 and dfrA5 were present in three (3.4%) of the isolates. The results showed that of the ESBL-producing isolates, 85.2% (n = 122), 53.2% (n = 76) and 26.1% (n = 37) were blaTEM, blaSHV and CTX-M harboring isolates, respectively.
    Conclusions
    Our study indicated a high frequency of cotrimoxazole resistance gene in E. coli isolates from Ilam and Tehran (Milad) hospitals, and sul genes had a major role in cotrimoxazole resistance of these isolates.
    Keywords: Trimethoprim, Sulfamethoxazole Combination, Iran, Resistance, Escherichia coli
  • Majid Reza Erfanian Taghvaei, Maryam Mirzaie*, Ali Parsa, Taghi Ghiasi Moghadam Page 20
    Introduction
    Kikuchi-Fujimoto disease (KFD) is a benign, self-limited, inflammatory disorder, first reported in Japan. This condition is more prevalent among women and typically occurs in the third decade of life. It normally manifests as persistent, isolated cervical adenopathy with a recurrence rate of 3%. The identification of this condition is of high significance, given the risk of misdiagnosis with other disorders such as malignant lymphoma and extensive necrosis.
    Case Presentation
    The patient was a 32-year-old female diagnosed with Kikuchi-Fujimoto disease via neck lymph node biopsy in August 2006 in the city of Mashhad, Iran. The disease regressed with proper follow-up, although after eight years the patient was readmitted to the hospital with severe weight loss, high fever, and uncommon symptoms of generalized adenopathy in cervical, axillary and inguinal regions.
    Conclusions
    Although KFD is an uncommon condition, it should be featured in the list of differential diagnoses of tender lymphadenopathy, especially lymphadenopathy localized to the cervical region. We reported a case of KFD with a prolonged relapse of eight years. Full recovery with a good response to corticosteroid regimen was achieved after the recurrence.
    Keywords: Kikuchi, Fujimoto Disease, Recurrent, Cervical Lymphadenopathy