فهرست مطالب

Avicenna Journal of Clinical Microbiology and Infection - Volume:1 Issue:3, 2014
  • Volume:1 Issue:3, 2014
  • تاریخ انتشار: 1393/08/19
  • تعداد عناوین: 8
|
  • Mohammad Mahdi Majzoobi, Mojgan Mamani, Masoud Ghiasian, Elham Abdoli * Page 1
    Introduction
    Acute disseminated encephalomyelitis (ADEM) is an acute inflammatory and demyelinating disease of the central nervous system, resulting in various neurological symptoms. Usually, the disease appears following vaccination or systemic viral infections. In rare cases, the disease appears following pneumococcal infections..
    Case Presentation
    The patient was a 27 year-old man who was referred to the clinic following a few days of fever and cold with consciousness deficit and right hemiplegia. Based on the analysis of cerebrospinal fluid (CSF) and diagnosis of pneumococcal meningitis, he received suitable antibiotic treatment. Despite complete return of consciousness, good general condition, and negative smear and culture of CSF, fever continued and no considerable improvement was observed in the hemiplegia. Therefore, brain magnetic resonance imaging (MRI) was performed and according to the findings, treatment was started with the diagnosis of acute disseminated encephalomyelitis. Treatment with prednisolone at first obviated the fever and after a month brought about a complete hemiplegia cure. Following the status of the patient after three months, his MRI clearly showed considerable reduction in lesions..
    Discussion
    There is possible occurrence of ADEM following pneumococcal meningitis. Regarding the occurrence of neurological symptoms such as visual disturbance, hemiparesis or hemiplegia following bacterial meningitis, ADEM can be considered as one of the differential diagnoses to be accompanied by MRI. Acute disseminated encephalomyelitis should be treated using suitable dose of corticosteroids..
    Keywords: Encephalomyelitis, Inflammatory, Demyelinating Autoimmune Disorders CNS, Meningitis, Streptococcus pneumoniae
  • Hossien Fazeli, Azadeh Taraghian *, Razie Kamali, Farkhondeh Poursina, Bahram Nasr Esfahani, Sharareh Moghim Page 2
    Background
    Multidrug resistant (MDR) and extensively drug resistant (XDR) Acinetobacter baumannii are among important causes of nosocomial infections and cause therapeutic problems worldwide. The emergence of extensively drug-resistant A. baumannii (XDRAB) cause serious threats to hospital acquired infections (HAI) worldwide and further limit the treatment options..
    Objectives
    The current study aimed to identify and isolate the MDR and XDR Acinetobacter baumannii from different wards of a teaching hospital in Isfahan, Iran, and determine the susceptibility pattern of these bacteria..
    Materials And Methods
    One hundred and twenty one (121) isolates of A. baumannii collected from a teaching hospital in Isfahan, Iran, within eight months (between September 2013 and April 2014) were included in the current study. The samples were isolated from different wards and different specimens. To confirm the species of A. baumannii, Polymerase chain reaction (PCR)was conducted to identify blaoxa-51 gene. Disk diffusion method was employed to evaluate antimicrobial susceptibility against cefotaxime, ceftriaxone, ampicillin-sulbactam, cefepime, meropenem, tobramycin, amikacin, tetracycline, ciprofloxacin, trimethoprim- sulfamethoxazole, and aztreonam..
    Results
    Among the 121 isolated A. baumannii, 44% and 56% were isolated from female and male, respectively. Samples cultured from the trachea (36%), urine (15%), blood (10%), wound (10%), cerebrospinal fluid (7%), bronchial (4%) and the others (18%). Most of the isolates (50%) were obtained from intensive care unit (ICU). Isolated A. baumannii showed high resistance to the evaluated antibiotics except ampicillin-sulbactam, which showed only 33.9% resistance. Also, 62.8% and 100% of the isolates were identified as XDR and MDR..
    Conclusions
    The result of the current study showed the growing number of nosocomial infections associated with XDR A. baumannii causing difficulties in antibiotic therapy. Resistant strains increasingly cause public health problems; therefore, their early detection is essential for healthcare centers..
    Keywords: Acinetobacter baumannii, Drug Resistance, Multidrug Resistant (MDR), Extensively Drug Resistant (XDR)
  • Peyman Eini, Fariba Keramat *, Nasim Farajpoor Page 3
    Background
    Chlamydia pneumoniae has been linked with increased risk of cardiovascular diseases; however, data on stroke and cerebrovascular accidents are sparse..
    Objectives
    The aim of this study was to determine the association between C. pneumoniae infection and ischemic stroke..Patients and
    Methods
    In a case-control study, 141 patients, admitted with ischemic stroke, were compared with gender and age-matched control subjects (n = 141). Using an enzyme-linked immunosorbent assay kit, the presence of C. pneumoniae IgG and IgA in the patients’ sera was determined. The data were analyzed by SPSS software (version 15) and were compared between the two groups using T-test and chi square test..
    Results
    The mean ages of the case and control groups were 68.97 ± 12.29 and 66.95 ± 6.68 years old, respectively. The difference between these two groups was not statistically significant (P = 0.102). The seroprevalence of C. pneumoniae-specific IgG were 78.7% in the patients with stroke and 52.5% in the control group. The difference between the two groups was statistically significant (P = 0.0001). The seroprevalence of C. pneumoniae-specific IgA were 41.1% in the stroke and 15.6% in the control group. The difference between the two groups was statistically significant (P = 0.0001)..
    Conclusions
    The results supported the hypothesis that serological evidence of C. pneumoniae infection may be associated with an increased risk of ischemic stroke and cerebrovascular accident..
    Keywords: Chlamydia pneumoniae, Cerebrovascular Accident, Stroke
  • Fariba Keramat, Mojgan Mamani *, Mahdi Samadi, Somaieh Mohammadnezhad, Peyman Eini, Abbas Moradi Page 4
    Background
    Hepatitis E virus (HEV) infection is a self-limited hepatitis and the most common cause of acute adult hepatitis in Asia. Young adults and middle-aged populations are more likely to be infected than other age groups..
    Objectives
    The aim of this study was to determine the seroprevalence of anti-HEV among injection drug users (IDUs) compared to non-IDUs..Patients and
    Methods
    This was a cross-sectional study performed on 131 IDUs referred to Farshchian Hospital, Hamadan, Iran and 131 non-IDUs selected from healthy visitors between March 2011 and March 2012. Anti-HEV IgG was measured in serum by ELISA method (DiaPro, Milan, Italy). Data including age, gender, education, location and duration of injection drug used were collected using a questionnaire..
    Results
    In this study, the seroprevalence of hepatitis E virus antibody among IDUs group was 6.1%, and 1.5% among non-IDU group (Odds Ratio = 5.48; CI = 1/069-22/84), indicating that injection drug users were almost five and a half times more than non-IDUs at risk of HEV infection (P = 0.053). There was no significant association between seroprevalence of hepatitis E virus and education level (P = 0.46), duration of injection (P = 0.38) and location (P = 0.19)..
    Conclusions
    Seroprevalence of hepatitis E virus among IDUs group was higher than non-IDU group, which might be due to possible blood transmission of HEV among IDUs..
    Keywords: Injection, Drug Users, Hepatitis E Virus, Seroprevalence
  • Mahdi Askari Badouei *, Samad Lotfollahzadeh, Moein Arman, Masoud Haddadi Page 5
    Background
    Shiga toxin-producing Escherichia coli (STEC) strains are considered as one of the most important widespread food-borne pathogens, which cause diarrhea and life threatening diseases, such as hemolytic uremic syndrome, in humans. More recently, the STEC strains have also been incriminated to cause diarrhea and hemorrhagic colitis in calves; enteropathogenic E. coli (EPEC) also causes diarrhea in neonate animals..
    Objectives
    This study aimed to study the prevalence and antibacterial resistance patterns of STEC and EPEC in fecal samples from diarrheic calves in Mashhad and Garmsar districts, Iran..
    Materials And Methods
    A total of 115 fecal samples were collected from diarrheic animals, 75 from Mashhad and 40 from Garmsar districts. A total of 146 E. coli isolates were obtained from culture and subjected to multiplex-PCR assay targeting stx1, stx2, eaeA and ehly virulence genes. The antibacterial resistance patterns of the virulence-positive isolates were determined using disc diffusion method..
    Results
    Eight samples (6.9%) carried the strains with positive results for at least one of the tested virulence genes. Five samples (4.3%) contained the stx-positive strains (STEC) and three (2.6%) carried the eaeA-positive and stx-negative strains, which were categorized as EPEC. In nine virulence-positive E. coli isolates, stx1 (n = 6) was the predominant virulence gene, followed by ehly (n = 5), eae (n = 4), and stx2 (n = 2). Antibacterial resistance patterns of virulence-positive isolates were also determined and nine resistance profiles were discriminated; higher rates of resistance were observed in isolates from Mashhad..
    Conclusions
    This study indicated that other pathologic factors might play a more important role in calf diarrhea in the studied areas, but public health significance of these strains should not be overlooked..
    Keywords: STEC, EPEC, Calf Diarrhea, Antibacterial Resistance
  • Mahbobeh Barakzahi, Bahman Hormozi, Ahmad Rashki *, Zahra Rashki Ghalehnoo Page 6
    Background
    Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumonia has become widespread in hospitals and is increasing in community settings. Most of K. pneumonia that harbor these enzymes, display resistance to other unrelated antimicrobial agents and thus, often pose a therapeutic dilemma..
    Objectives
    This study was conducted to determine the prevalence of ESBL-producing K. pneumonia in a major university hospital in Zahedan, Iran..
    Materials And Methods
    The susceptibility of 83 K. pneumonia isolates to 12 antibiotics was assessed using Kirby-Bauer disc diffusion method. For the ESBL phenotypic test, double-disk diffusion (DD) method was used..
    Results
    The highest resistance rates of the isolates were seen against cefixime (82%), cefotaxime (81%), ceftriaxone (73%), ceftazidime (72%), and azithromycin (60%), consecutively. The lowest resistance rates were observed against gentamicin (58%), tetracycline (59%), nalidixic acid (59%), and amikacin (63%), consecutively. ESBLs were found in 65% of K. pneumonia isolates..
    Conclusions
    We found that 65% of K. pneumonia isolates produced ESBL. Therapeutic strategies to control infections should be carefully formulated in teaching hospitals. The high percentage of drug resistance in ESBL-producing K. pneumonia suggests that routine detection of ESBL by reliable laboratory methods is required..
    Keywords: Antibiotic Resistance, Extended Spectrum Beta Lactamase, Antimicrobial Susceptibility, Klebsiella pneumonia
  • Masoud Rahdar, Ahmad Rashki *, Hamidreza Miri Page 7
    Background
    Escherichia coli is one of the most causative pathogen of urinary tract infection. Urinary tract infections (UTIs) are the second most common cause of morbidity and remain a serious health concern among the clinicians. The severity of UTI caused by uropathogenic E. coli (UPEC) is due to the expression of a wide spectrum of virulent factors such as adhesin coding operons. Little is known about the relationship between the E. coli genetic background and the acquisition of adhesin coding operons in UPEC isolates..
    Objectives
    The aim of this study was to determine the prevalence of adhesin coding operons in UPEC isolates belonged to phylogenetic group B2 and A collected from patients suffering from UTI..
    Materials And Methods
    A total 100 UPEC isolates were used for DNA extraction by the boiling lysis. The analysis of phylogenetic groups, along with detection of adhesin coding operons was performed by Multiplex-PCR method. Associations were assessed between afa, fim, foc, pap and sfa operons among to 55 B2 and 17 A groups E. coli isolates. Statistical analysis was performed using Fisher exact test..
    Results
    Phylogenetic analysis showed that 55 and 17 of 100 UPEC isolates belonged to the B2 and A phylogenetic groups, respectively. The afa, fim, foc, pap and sfa operons were present in five (9.09%), 55 (100%), 16 (29.09%), 46 (83.63%) and 46 (83.63%) of UPEC isolates belonged to phylogenetic group B2, and two (12.50%), 14 (87.50%), one (6.25%), two (12.5%) and 12 (75%) of isolates belonged to phylogenetic group A, respectively. Statistical analysis showed that pap gene was significantly more frequently detected in phylogenetic group B2 (P < 0.05)..
    Conclusions
    The UPEC isolates belonging to group B2 harbored a greater number of adhesin coding operons than strains from phylogenetic groups A..
    Keywords: Phylogenetic Analysis, Urinary Tract Infections (UTI), Uropathogenic Escherichia coli, Virulence Factors
  • Ramin Mazaheri Nezhad Fard *, Mary D. Barton, Michael W. Heuzenroeder Page 8
    Background
    In recent decades, bacterial antibiotic resistance (especially in enterococci) has become a significant problem for human and veterinary medicine. One of the most important antibiotic resistances in enterococci, vancomycin resistance, is encoded by van gene family..
    Objectives
    The aim of this study was to investigate antibiotic resistance to vancomycin in enterococci and the genes responsible for this resistance..
    Materials And Methods
    Two-hundred and thirty enterococcal isolates from pigs (207 isolates), chickens (15 isolates) and humans (eight isolates) were phenotypically and genotypically tested for resistance to vancomycin by minimum inhibitory concentration (MIC) and polymerase chain reaction (PCR). The van genes were confirmed by gene sequencing..
    Results
    Of the total isolates, 19% were phenotypically resistant to vancomycin, while nearly 15% contained either vanC1 or vanC2 gene. One resistant E. casseliflavus isolate with pig origin (MIC > 8 μg/mL) contained both vanC1 and vanC2 genes. Furthermore, one vanC1 was found in a sensitive E. faecalis isolate of pig origin (MIC ≤ 4 μg/mL) and one vanC2 in a resistant E. faecium isolate of chicken origin (MIC > 32 μg/mL). These genes were not accompanied by other van genes. Other detected genes were vanA in 11 E. faecium isolates of chicken origin (MIC > 32 μg/mL). No vanB genes were found. Gene sequencing results showed 100% identity with GenBank reference genes..
    Conclusions
    The current report is the first report on the detection of vanC1 and vanC2 genes in one enterococcal species with pig origin. This report is important as it proves the horizontal transfer of various vanC genes to one species possibly due to the compatibility class of plasmids. Furthermore, detection of vanC genes in E. faecalis and E. faecium isolates is important as it suggests that resistance to vancomycin in non-motile enterococci can be encoded by several mechanisms..
    Keywords: Enterococcus, Antibiotic Resistance, Vancomycin