فهرست مطالب

Medical Bacteriology - Volume:1 Issue: 1, 2012
  • Volume:1 Issue: 1, 2012
  • تاریخ انتشار: 1391/05/20
  • تعداد عناوین: 8
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  • Parviz Owlia Page 1
    Over the past few decades, the science of microbiology in general and bacteriology in particular, has played a key role in fighting against infectious diseases and improving public health worldwide. During this period, we learned that as our knowledge of microbiology increases, we will face yet more scientific questions some of which may not be easy to answer. We have also learned that solving a scientific puzzle may open new sets of even more challenging questions. This is the nature of science and in our country, we as scientists, have an obligation to challenge these questions by sharing our knowledge, experience and our findings with other scientist through publications in scientific journals.
  • Hossein Goudarzi, Hanieh Rezaee, Mitra Rafizadeh, Afsoon Taghavi Page 3
    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.
  • Solmaz Ohadian Moghadam, Seyed Asghar Havaei, Mohammad Reza Pourmand Page 9
    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.
  • Javad Saraylu, Jalil Fallah Mehrabadi, Abbas Ali Imani Fooladi, Aylar Sabbaghi, Hedrosha Molla Aghamirzaei, Mohsen Hasankhani Page 17
    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.
  • Mehrdad Asghari, Siamak Heidarzadeh, Ziba Vaise Malekshahi, Maryam Hemmatzadeh, Mohammad Javad Razzaghe Karimi, Hamideh Ashrafi, Fatemeh Fallah, Raheleh Sadat Sajadi Nia Page 23
    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 through 2011 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.
  • Mohammad Mehdi Soltan Dallal, Farhad Nikkhahi, Saber Molaei, Kazem Hosseini, Zohreh Kalafi, Ahad Khoshzaban, Abdolaziz Rastegar Lari, Ahmad Kheirkhah, Mohammad Kazem Sharifi Yazdi Page 31
    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.
  • Seyyed Saeed Eshraghi Page 38
    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.
  • Leila Azimi, Reza Alaghehbandan, Masoud Mohammadpoor, Abdolaziz Rastegar Lari Page 46
    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.