فهرست مطالب

Avicenna Journal of Clinical Microbiology and Infection
Volume:4 Issue: 3, Aug 2017

  • تاریخ انتشار: 1396/09/06
  • تعداد عناوین: 7
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  • Rahem Khoshbakht, Mohammad Tabatabaei, Saeid Hosseinzadeh Page 1
    Background
    Several genetic mechanisms are used by Campylobacter spp. to achieve pathogenesis. One of the involved virulence factors is lipooligosacharide-associated genes, which are related to ganglioside mimicry by Campylobacter species.
    Objectives
    The current study was conducted to determine the genetic diversity of 3 LOS-associated genes among Campylobacter jejuni and C. coli isolated from animal fecal samples.
    Methods
    One hundred broiler, cattle, and sheep fecal C. jejuni and C. coli isolates, which had been collected previously from Shiraz slaughterhouses and had been formerly identified by polymerase chain reaction (PCR) reactions, were used in the present study. Campylobacter species were subjected to detect wlaN, cgtB, and waaC genes. The PCR products of three LOS-genes were subjected for restriction fragment length polymorphism (RFLP) using HindIII and AluI restriction enzymes in separate reactions. The most prevalent RFLP patterns in the combination of 2 enzymes were subjected for sequencing and sequence analysis software.
    Results and
    Conclusions
    Patterns of RFLP for PCR products of all 69 wlaN and 29 cgtB genes were similar yet among 86 waaC gene PCR products, 6 different RFLP patterns were obtained. In conclusion, PCR-RFLP analysis demonstrated considerable variation in gene content and overall sequence heterogeneity in the animal-associated C. jejuni and C. coli LOS biosynthesis genes.
    Keywords: Campylobacter, Virulence Factors, Polymerase Chain Reaction, Restriction Fragment Length Polymorphism
  • Seyed Mostafa Hosseini, Pezhman Karami, Hamid Kazemian, Zahra Karimitabar, Ali Mohamadi Bardbari, Azad Khaledi, Mohammad Reza Arabestani Page 2
    Background
    Staphylococcus aureus is an important cause of hospital and community acquired infections. Food borne diseases are an important problem in public health. Protein A is a protein 42 KDa, which is expressed in all strains of this bacterium.
    Objectives
    This study aimed to evaluate the relationship between antibiotic resistances with spa gene polymorphism.
    Methods
    A total of 1,050 food samples were collected during 8 months in Hamedan, Iran. Food samples were evaluated for the presence of spa genes of S. aureus. The antibiotic susceptibility testing was performed using disk diffusion agar. After extraction of genomic DNA, nuc and spa genes were detected. Finally, with the PCR-RFLP method, spa typing was performed. The relationship between the antibiotic resistance rate and Spa types were analyzed by the SPSS software.
    Results
    Results showed that the 98 cases (9.33%) of S. aureus were isolated. The most frequent resistance was observed against tetracycline (8.41%). Spa gene was reported in all isolates and 4 different patterns of spa gene was seen. Furthermore, a significant correlation between different strains isolated from diverse foodstuffs and different patterns of spa (P
    Keywords: Antibiotic Resistance, spa Gene
  • Hamid Staji, Elham Shahaboddin, Khatereh Kafshdouzan Page 3
    Background
    Escherichia coli is a typical occupant of the enteric system of vertebrates. Some E. coli strains are related to urinary tract infections (UTIs) in human. E. coli strains are divided namely to the four phylogenetic groups, A, B1, B2, and D. Some investigations have indicated the relationship between phylogenetic characteristics and pathogenicity of E. coli. Thus, determining the phylogeny of unknown E. coli strains may be useful in predicting the pathogenesis.
    Objectives
    In the present study, we aimed to compare the distribution of E. coli phylogroups in human UTIs and wild bird feces as a possible source of infection for human in a cross-sectional survey.
    Methods
    A total of 264 E. coli isolates were obtained from human UTIs and feces of wild birds around and phylogenetic determination was carried out using the Clermont Triplex-PCR technique.
    Results
    Our results showed that phylogenetic group B2 strains were the most prevalent in UTI cases (47.2%) followed by group D (30.2%). Group B1 contained 32.5% of the isolates in feces of wild birds, followed by group A (27.5%). There was a significant difference in E. coli phylogeny between hosts so that groups B2 and D were more prevalent in human UTIs and groups B1 and A in wild birds. Also, when comparing the phylogroups within a host, group B1 showed a higher rate in wild birds than in human UTIs.
    Conclusions
    Although the majority of isolates from wild birds belonged to nonpathogenic phylogenetic groups B1 and A, further research seems to necessary to assess the exact relation of wild birds as pathogen sources for human by genotyping E. coli strains via high throughput genotyping assays.
    Keywords: Phylogeny, Human UTI, Wild Bird Feces, Escherichia coli
  • Fahimeh Ghanbari, Farzad Khademi, Shirin Saberianpour, Mojtaba Shahin, Nafiseh Ghanbari, Kourosh Naderi, Tahereh Motalebi-Rad Page 4
    Background
    Urinary tract infection (UTI) is one of the most common bacterial diseases in outpatients and inpatients worldwide. Treatment of UTI has become challenging due to the emergence of pathogens with increasing resistance to antimicrobial agents.
    Objectives
    The aim of this study was to determine the prevalence and antimicrobial resistance patterns of main bacteria responsible for UTI.
    Methods
    In this study, 326 patients with UTI, referring to Shahid Motahari hospital of Fuladshahr, Iran, were evaluated between March 2015 and February 2016. The isolated bacteria were identified by biochemical tests. Disk diffusion method was applied to determine the antibiotic sensitivity of bacterial agents.
    Results
    In a total of 326 positive urine cultures, 273 (83.74%) and 53 (16.25%) samples belonged to females and males, respectively. The most prevalent isolates were Escherichia coli (58.28%), Klebsiella spp. (11.65%), Staphylococcus spp. (11.65%), Enterobacter spp. (7.05%), Streptococcus spp. (3.68%), Enterococcus spp. (2.45%), Proteus spp. (1.22%), Pseudomonas spp. (0.61%), and Citrobacter spp. (0.61%), respectively. The antimicrobial susceptibility analysis of E. coli, as the predominant cause of UTI, revealed the following
    Results
    gentamicin (28.6%), ciprofloxacin (48.4%), nitrofurantoin (12.2%), nalidixic acid (63.7%), trimethoprim/sulfamethoxazole (67.9%), cephalothin (60%), cefotaxime (44.8%), imipenem (9.5%), amikacin (66.7%), and ampicillin (85.3%).
    Conclusions
    According to the present survey, E. coli isolates were the predominant pathogens in UTIs and were more prevalent in women than men. In the present study, the frequency of UTI pathogens was comparable to that reported in previous studies, showing an increasing resistance pattern to commonly prescribed antibiotics.
    Keywords: Urinary Tract Infection, Antimicrobial resistance, E. coli
  • Mojdeh Hakemi-Vala, Ayda Eslamzadeh, Fatemeh Bagheri Bejestani, Jinous Asgarpanah, Mohsen Heidary, Saeed Khoshnood Page 5
    Background
    Increased microbial resistance to conventional medicines and their side effects have led to studying the effect of herbal extracts on microorganisms.
    Objectives
    The current study aimed at evaluating the antimicrobial activity of total extract and fractions of chloroform, methanol, and aqueous of aerial parts of Salvia aegyptiaca.
    Methods
    The plants were collected from Bandar Abbas, Iran, in April 2015. The methanol extract of aerial parts, in addition to chloroform, methanol, and aqueous fractions, were prepared by the maceration method from S. aegyptiaca. The antimicrobial activity of fractions were determined by cup plate and further micro-dilution methods based on the Clinical and Laboratory Standards Institute (CLSI) 2013 against some Gram-positive and -negative bacteria as well as Candida albicans. Statistical analysis was conducted by t test.
    Results
    Significant results were obtained regarding the tested microorganisms only by micro-dilution method.
    Conclusions
    There were no significant results in plant extract and its fractions against the tested microorganisms in the cup plate method, which may be due to the inability of agar diffusion. In contrast, by excluding the agar’s hindrance property, verified results of micro-dilution method were deleted.
    Keywords: Gram-Positive Bacteria, Gram-Negative Bacteria, Microbial Drug Resistance, Candida albicans
  • Azad Khaledi, Omid Elahifar, Hossein Vazini, Mohammad Yousef Alikhani, Afsane Bahrami, Davoud Esmaeili, Kiarash Ghazvini Page 6
    Background
    Nosocomial infections due to high mortality and economic cost are one of the most important challenges that hospitals face with it. Reports show that hospital acquired pneumonia (HAP) is the second most common nosocomial infection in some countries such as the United States.
    Objectives
    The aim was to study the frequency and resistance pattern of Acinetobacter baumannii isolates against imipenem.
    Methods
    This cross-sectional study was conducted for 2 years on patients with nosocomial pneumonia caused by A. baumannii in 2 major university hospitals in Mashhad, Iran. After detection and identification, data regarding mortality, length of hospital stay, and treatment were collected. Furthermore, the pattern of antibiotic resistance was investigated in A. baumannii against imipenem.
    Results
    In this study, among 700 patients with nosocomial pneumonia, 364 and 336 of those were male and female, respectively. All of these received imipenem. Of the total patients, 317 cases (45%) were resistant to imipenem. 84% of these patients were cured and the remaining 16% expired (P value = 0.001). A. baumannii resistance to the imipenem in both hospitals had an increasing rate. The resistance rate in the Ghaem hospital increased 96.6% at the end of the period compared to beginning of study (P value = 0.004). Also, a similar increase (94.7%) was observed in the Imam Reza hospital (P value = 0.003).
    Conclusions
    According to our results, excessive use of imipenem has been caused by antibiotic resistance, for this, the appropriate selective choice of antibiotics should be considered. At first, other antibiotics such as new generations of cephalosporins should be chosen for empirical treatment of A. baumannii.
    Keywords: Imipenem, Hospital Acquired Pneumonia, Acinetobacter baumannii
  • Ali Pashaei Zanjani, Negin Esmaeilpour, Mehrnaz Rasoolinejad, Pardis Moradnejad, Mojtaba Hedayat Yaghoobi Page 7
    Background And Objectives
    Considering reductions in AIDS-related mortalities following effective anti-retroviral treatments in HIV/AIDS patients, HCV-associated liver diseases have turned into a major concern for HIV/HCV co-infected patients. The present study aims at determining SVR rates in HIV/HCV co-infected patients under pegylated interferon and ribavirin treatment referring to Tehran Imam Khomeini hospital during 2010 - 2013.
    Methods
    In this descriptive cross-sectional study, all HIV/HCV co-infected patients under pegilated interferon and ribavirin treatment referring to Tehran Imam Khomeini Hospital during 2010 - 2013 entered the study. The variables include demographic information, genotype, liver involvement stage in biopsy, viral load levels prior to treatment, 4th, 12th, and 48th week as well as 6 months after treatment (sustained virologic response (SVR)), and CD4 count every 3 months.
    Results
    In the total of 28 male HIV/HCV co-infected patients of this study, 21.4% and 78.6% received peg IFN alfa- 2b, and pegIFN alfa- 2a, respectively. There were 17 genotype I (61%), 9 (32%) genotype III, and 2 (7%) genotype II among the patients. The overall SVR rate of the patients was 67.8%; it was 52.9% in genotype I and 72.7% in genotypes II and III. Despite the CD4 count decline during treatment, opportunistic infections were not observed in any of the patients
    Conclusions
    SVR rates in this study are higher than studies conducted in other countries and this implies the possibility of a more favorable genetic trait in Iranian HCV patients responding to pegIFN and ribavirin. That is still the proper regimen due to high price of free interferon regimens in Iran.
    Keywords: HIV Infection, AIDS, Hepatitis C, Interferon, Alfa