Vol 1 No 1-2 (2012)

Published: 2012-10-12

Original Articles

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    Background: Many  Helicobacter pylori strains express adhesin proteins that bind to specific  host-cell  macromolecule  receptors,  like sialic acid binding adhesion (sabA).   SabA-expressing  strains have been associated with gastric cancer  and  negatively  associated   with  duodenal   ulcers. The  aim  of  this study  was  to  determine   the  status  of  sabA  gene  of  H.  pylori   and  its association  with the clinical diseases in Iranian dyspeptic pateints.Methods:  Eighty six biopsy block samples  that were positive  for H. pylori according Geimsa staining were included in  this study. Genomic DNA was extracted  from paraffin-embedded  gastric biopsies  obtained  from dyspeptic patients.     The     identity     of     Helicobacter      genus     was     determined through amplification  of 16S rRNA which followed  by sabA PCR using the gene-specific primers.  The prevalence  of sabA gene in three clinical groups including gastritis, gastric ulcer, and gastric atrophy was determined. The association  of  sabA  gene  and  clinical  outcomes  was  assessed  statistically using Chi-square  test. A p-value less than <0.05 was considered  statistically significant.Results:  Total  of 86 patients  was  included  in this study.  Seventeen  cases out  of  86  (23.6%)   were  yielded   a  positive   result  for  sabA  gene.  The prevalence  of sabA   gene   was   28.6%   in   both   dyspeptic   and   Gastric atrophy  patients  as compared with peptic ulcers (19.2%).Conclusion:   For  a  first  time  the  frequency   of  sabA   gene  using  PCR methods  was reported.  The current  study demonstrated  that the sabA  gene status was not associated with clinical diseases. In limited number of studied samples,  higher  frequency  of  sabA  gene  among  dyspeptic   and  atrophic patients was found. 
  • XML | PDF | downloads: 232 | views: 330 | pages: 9-16
     Background:  Methicillin-Resistant   Staphylococcus   aureus  (MRSA)   is  a major cause of Nosocomial and community infections that are becoming increasingly difficult to combat, because of emerging resistance to all classes of antibiotics. Moreover Panton-Valentine  leukocidin (PVL) is an important virulence factor in S. aureus and causes white blood cell destruction, necrosis and  accelerated  apoptosis.  The  aim  of  this  study  was  to  determine  the frequency  of  PVL-positive  MRSA  in  cutaneous  infections,  for epidemiological  purposes  and also to determine  antibiotic  resistance  of the isolates.Methods: Collectively,  56 isolates of S. aureus were obtained from Isfahan University of Medical sciences affiliated hospitals and confirmed with biochemical tests (coagulase, mannitol fermentation, and DNase). Then polymerase  chain  reaction  (PCR)  was  used  to detect  pvl  gene.  Coagulase gene was used as internal control. The antibiotic susceptibility of all isolates to methicillin was determined using disk diffusion method.Results: Out of 56 isolates 14.3% were PVL positive that 37.5% were from abscess  and  62.5%  were  from  wound.  Among  all of these  isolates  67.8% were MRSA and also 75% of PVL-positive isolates were MRSA.Conclusion: The prevalence of PVL positive MRSA in cutaneous isolates is high. Future works are necessary for a more complete understanding of distribution of these virulent isolates in nasal carriers to decrease the risk of infections
  • XML | PDF | downloads: 251 | views: 319 | pages: 17-22
    Background:  One of the most common infections in human is urinary tract infection  (UTI)  and  Uropathogenic  Escherichia  coli  is  one  of  its  major causative agents. UTI is extremely common among young women. Children under age 5 are also highly at risk. Considering the prevalence of this disease, it is necessary  to design  an appropriate  diagnostic  method  for its effective diagnosis.  The aim of present  study was to identify  the prevalence  of two virulence genes (sat and vat) among Uropathogenic E. coli isolates.Methods: Urine samples were taken from 350 patients with urinary tract infection. The samples were cultured on EMB agar and Blood agar. The suspected E. coli colonies were isolated and confirmed by biochemical tests. The genomic DNA was extracted from 297 isolated E. coli and target genes were amplified  by PCR. The amplicons  were sequenced  and analyzed  with ClustalW  software.  Moreover,  data analysis  was performed  by using SPSS software.   Subsequently,   Duplex   PCR   was   optimized   for   simultaneous detection of two genes.Results: The prevalence of sat and vat genes were 75 (n: 225) and 36 (n: 106)percent,  respectively.  In addition,  less  than  4%  (n: 11)  of  clinical  isolates comprised two genes.Conclusion: According to the conducted research, molecular identification of Uropathogenic E .coli strains according to detection of sat gene is potentially an appropriate method and could be noted for diagnosis.
  • XML | PDF | downloads: 281 | views: 414 | pages: 23-30
    Background:  Tuberculosis  is one of the most important causes of morbidity and mortality worldwide. Approximately 10-20% of tuberculosis is Extra- pulmonary tuberculosis (EPTB), which is much higher (50%) in patients suffering from immunity defects such as AIDS. EPTB diagnosis is difficult mostly because of various clinical manifestations  and aggressive  procedures needed for its diagnosis.  The main goal of this study was to determine  the prevalence  of  EPTB  in the  north  west  of  Iran  and  also  to investigate  the different clinical characteristics of the studied population, the various clinical manifestations and organ involvement of EPTB, as well.Methods:  This  study  was  carried  out  retrospectively  using  the  data  from Tabriz Tuberculosis  and Lung Disease  Research  Center from 2007 through 2011.   Questionnaires   were  designed   to  extract   relevant   information   to describe characteristics of EPTB affected population and also various clinical manifestations and organ involvement of the disease among the patients. Results:  The  study  included  203  EPTB  cases  notified  from  2007  through2011 including, 91 (44.83%) males and 112 (55.17%) females. The mean age of the patients was 46.55 ± 18.3. The main extra pulmonary involvements of the  studied  population  were  lymphadenitis  (9.35%),  pleural  (7.39%)  and spinal  (5.42%)  among  males  and  lymphadenitis  (17.24%),  ocular  (7.88%), pleural (6.40%) and spinal (5.91%) among females, respectively.Conclusion:  Since EPTB diagnosis is a challenging and time sparing attempt even by the expert physicians, there is a need to perform further researches in order to identify the main clinical manifestations  and organ involvement  of EPTB in patients. 
  • XML | PDF | downloads: 214 | views: 275 | pages: 31-37
    Background:  Keratitis caused by Pseudomonas  aeruginosa  is often resulted in  severe  corneal  ulcers  and  perforation,  which  leads  to  losses  of  vision. Human amniotic membrane (HAM) forms the inner wall of the membranous sac which surrounds and protects the embryo during gestation. The purpose of this  study  was  to  evaluate  the  effectiveness  of  the  amniotic  membrane's healing in rabbits with pseudomonas keratitis.Methods:  In total 14 rabbits divided in 2 groups of: 1 as Control  and 2 as experimental  amniotic  membrane  combined  with  ciprofloxacin.  A 0.05  ml suspension   of  Pseudomonas   aeruginosa   ATCC  27853  was  injected  into rabbit’s corneal stroma, with no interference in control group. In the second group, the amniotic membrane in pieces of 1.5 × 1.5 cm transplanted  to the entire corneal surface by eight interrupted 10.0 nylon sutures. In the first day ciprofloxacin  drop was injected  to the second  group  every 30 minutes  and through second to seventh days every 2 hours. The results of perforation  in cornea and the amount of infiltration were registered.Results:  The  results  showed  that  amniotic  membrane  transplantation (AMT)  +  ciprofloxacin  group  had  0%  perforation  and  the  control  group 85.6%. Average infiltrations were 5 mm in AMT + ciprofloxacin groups and 23.75 mm in control.Conclusion: The use of amniotic membrane with ciprofloxacin was effective in   prevention   of   cornea   perforation   and   controlling   the   process   of pseudomonal  keratitis remission.  The improvement  of inflammation  rapidly happened in ciprofloxacin + AMT group. 

Review Articles

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    Identification  of clinically  significant  Nocardia  species  is essential  for the definitive diagnosis, predict antimicrobial susceptibility, epidemiological purposes,  and  for  an  effective  treatment.   Conventional   identification   of Nocardia species in routine medical laboratories which is based on phenotypic (cellular morphology, colonial characteristics), biochemical and enzymatic profiles, and chemotaxonomic characteristics is often laborious, and time- consuming.  The  procedure  requires  expertise,  and  newer  species  can  be difficult to differentiate with accuracy from other related species. Alternative methods  of identification,  such as high performance  liquid chromatography (HPLC) and molecular  biology techniques  allow a better characterization  of species.  The  taxonomy  of  the  genus  Nocardia  has  been  dramatically  been revised  during  the  last  decade  and  more  than  30  valid  human  clinical significance  species  of Nocardia  have been reported.  The use of molecular approaches, including 16S rRNA gene sequencing, restriction fragment length polymorphism (RFLP) or PCR restriction endonuclease analysis has been the focus  of  recent  investigations  to distinguish  the  isolates  of  Nocardia  from other  actinomycetes  genera.  The  methods  have  revolutionized the characterization  of the Nocardiae by providing rapid, sensitive, and accurate identification  procedures. The present  review  describes the currently  known medically important pathogenic species of Nocardia. 

Case Reports

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    The objective of this study was to determine the phenotypic characteristics of KPC-producing Pseudomonas aeruginosa and Acinetobacter baumannii isolates. A case report study was performed at a tertiary burn care centre in Tehran,  Iran.  Nine  isolates  of Pseudomonas  aeruginosa  and  Acinetobacter baumannii from a hospitalized case were isolated. The identity of isolates was confirmed and their antibiotic susceptibility testing was performed. Eight out of nine Pseudomonas aeruginosa and Acinetobacter baumannii isolates were resistant to Imipenem.  Three out of 8 imipenem  resistant isolates were also positive for KPC test. Findings of this study highlight the importance of implementation  of an effective infection control strategy in order to prevent and reduce the emergence and spread of gram negative Carbapenemase- producing organisms in Iran.