فهرست مطالب

Medical Bacteriology - Volume:5 Issue: 1, 2016
  • Volume:5 Issue: 1, 2016
  • تاریخ انتشار: 1395/01/15
  • تعداد عناوین: 9
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  • Mahdieh Rezaei, Mohammad Khalili, Baharak Akhtardanesh, Shima Shahheidaripour Pages 1-6
    Background
    Q fever is an important widespread reemerging zoonosis. The presence of C. burnetii in 100 tick-infested dogs was assessed in this study.
    Methods
    The blood samples from 100 referred dogs were acquired and evaluated by nested-PCR.
    Results
    C. burnetii was detected in 11 out of 100 (11%) blood samples. Most of the positive dogs were kept outdoor and fed on raw diet. Based on our findings, Q fever should be considered as an emerging disease in dogs in Iran; so, zoonotic importance of this population must be notified. To better understanding the role and pathogenic importance of dogs in Q fever outbreak and to determine whether this organism can be transmitted directly from dogs to human further in-depth studies are necessary.
    Conclusion
    It is determined that C. burnetii is present in dogs in southeast of Iran and people who are in contact with this population, especially asymptomatic ones are at increased risk of infection.
    Keywords: Q fever, Zoonosis, Dog, Nested Trans, PCR, Iran
  • Reza Naghiha, Mokhtar Khajavi, Mohammad Reza Bahreini, Ali Naghi Keshtkaran Pages 7-10
    Background
    Due to excessive consumption of synthetic drugs, drug resistance rate of pathogenic bacteria is increasing and there is an ever-increasing need to find new safe compounds to tackle this problem. This study was conducted to investigate the consequences of chavill extract on the growth and viability of gastrointestinal pathogenic bacterium and probiotics bacteria.
    Methods
    The experiment contained three levels of the chavill extract concentrations (0, 1 and 3%) which were added to the milk free fat in accompany with three probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei and lactobacillus plantaram) and a pathogenic gastrointestinal bacterium (Salmonella typhimurium). Bacterial inoculums (1×107 CFU/ml) with different concentrations of chavill extract were added to skimmed milk medium and bacteria growth were enumerated.
    Results
    The concentration of 1% chavill extract significantly increased the total count of probiotic bacteria compared to the control group, while the number of pathogenic bacteria was decreased. At 3% chavill extract the growth of Lactobacillus acidophilus and Lactobacillus plantaram were increased. On the other hand, it prevented the growth of Salmonella typhimurium
    Conclusion
    Chavill extracts would play as an alternative to antibiotics in pharmacological studies to decreases harmful bacteria and increase probiotic bacteria.
    Keywords: Probiotic bacteria, chavill extract, Lactobacillus
  • Ramezan Ali Ataee, Hassan Araqizade, Rezvan Yoosefi, Ali Mehrabi Tavana, Mohammad Hosein Ataee Pages 11-18
    Background
    This study aimed to evaluate antibacterial effect of Allium sativum, garlic extract on erythromycin and methicillin resistant bacteria isolated from an operating room in a teaching hospital in Tehran, I.R. Iran.
    Methods
    The antibacterial effect of garlic extract was investigated on 70 bacterial strains. The selected isolates were resistant to erythromycin and or methicillin, which were isolated from an operating room. Antibiotic sensitivity was done using an agar well diffusion procedure and either a micro dilution method. Each of the bacterial strains were exposed to concentrations of 4, 8, 12, 16, 20 and 24 µg/ml of garlic extract, separately. The growth rate of the strains was determined by measurement of the inhibition zone diameter, colony count and either by measurement of the optical density.
    Results
    The results showed that 70 (100%) of the strains in agar well diffusion method were sensitive to 4- 12 µg/ml of garlic extract with MIC 8 µg/ml. While, the results of micro dilution method showed that 40 out of 70 strains were MIC ≥ 12 µg/ml for GE.
    Conclusion
    The results of this study indicated that the MIC and minimum bactericidal concentration of garlic extract were 8 µg/ml and 16 µg/ml, respectively. These finding indicated that garlic extract inhibit the growth of erythromycin and methicillin resistant bacterial strains.
    Keywords: Agar Well Diffusion, Micro Dilution Methods, Allium Sativum (garlic), Methicillin, Erythromycin, Resistant
  • Mohammad Dadook, Sedigheh Mehrabian, Saeed Irian Pages 19-24
    Background
    Medicinal use of plants dates long back in the history of the human beings and has recently gained a great deal of importance in treating different diseases. Due to the importance of Pseudomonas aeroginosa strains as agents responsible for common secondary infections and their resistance to antibiotics and disinfectants, the present study aimed at investigating the antimicrobial effects of the plant Cyperus rotundus on multiple drug resistant (MDR) Pseudomonas aeruginosa strains.
    Methods
    Ethanolic extracts of Cyperus rotundus tuber were prepared by maceration. The antimicrobial effect of these extracts on Pseudomonas aeruginosa isolates (ie., sensitive to antibiotics and multiple drug resistant strains), isolated from clinical and soil samples, was determined by both disk diffusion and broth microdilution methods..
    Results
    It was revealed that ethanolic extract concentrations of Cyperus rotundus tuber higher than 0.1 mg/ml suppresses the growth of all antibiotic sensitive and resistant Pseudomonas aeruginosa strains which were used in this study.
    Conclusion
    It is concluded that Cyperus rotundus possesses antimicrobial properties and thus can be used in treating multidrug resistant Pseudomonas aeruginosa-induced wounds and infections.
    Keywords: Cyperus rotundus, Antibacterial, Pseudomonas aeruginosa, Medicinal plants
  • Masoumeh Ahmadi Jalali Moghadam, Hamidreza Honarmand, Sajad Asfaram Meshginshahr Pages 25-32
    Background
    River and underground waters are main sources of tap water in Guilan, Iran. Overland wastes move into rivers during periods of heavy or extended rain that is very common in the area. Pseudomonas aeruginosa, Legionella pneumophila, and Escherichia coli are main human pathogens with water source. This study is designed to determine the load of these bacteria in main water supplies of the area.
    Methods
    Samples were collected directly into sterile containers, concentrated by centrifuge, inoculated in enrichment medium and incubated for 3-4 days. DNA was extracted by using commercial kit. Several rounds of PCR was performed to search Pseudomonas aeroginosa, integron I, Metallo-β-lactamases gene, Legionella pneumoohila, mip gene, and Escherichia coli.
    Results
    About 92.0% of the samples showed bacterial contamination as revealed by PCR with primers of 16S rRNAgene, 9.5% of the samples had L. pneumophila, and 11,1% had Pseudomonas aeruginosa, but Escherichia coli was not detected. We found the mip gene in 66.6% of the samples with L. pneumophila. Metallo-β-lactamasesgene was found in 11.1% of all samples. We also found Integrin 1 in 28.5% of the samples with Pseudomonas aeruginosa.
    Conclusion
    This study indicates that in spite of chlorination, total bacterial contamination of pot waters in the area is high and contamination with L. pneumophila and Pseudomonas aeroginosa is considerable. It might be related to the biofilm formation and the growth of water microflora. It seems that free residual chlorine is ineffective. We suggest a more effective decontamination procedure based on modern technology.
    Keywords: tap water, Pseudomonas aeruginosa, Legionella pneumophila Escherichia coli, PCR
  • Hashem Fakhre Yaseri, Mehdi Shakaraby, Hamid Reza Bradaran, Seyed Kamran Soltani Arabshhi Pages 33-37
    Background
    Vaculating cytotoxic A (vacA) gene is one of the multiple Helicobacter pylori genotypes that produce a cytotoxin protein (VacA).This gene is a major cause of chronic peptic ulcers and gastric cancer. The aim of this study was to determine the correlation between vacA gene with peptic ulcer disease (PUD) and non-ulcer dyspepsia (NUD).
    Methods
    This was a case control study of 130 patients, aged 16-64, with positive H. pylori in histological and Giemsa reports. The case and control groups included 65 PUD patients and 65 NUD patients, respectively. The presence of the vacA gene genotypes was determined using polymerase chain reaction (PCR) on biopsy samples, taken by endoscopy.
    Results
    In the case group, gastric ulcer was detected in 41.5% (27) of the participants; of whom, 77.8% (21) were female; and duodenal ulcer was found in 58.5% (38) of the participants, of whom,42.1 % (16)were female. The control group (NUD) included 65 patients; of them,45% (29) were female and the average age was 36.4 ±10.8 years (18 to 60).The total frequency of the vacA gene was 53% (69/130),with 60% in the PUD and 46% in the NUD groups (Odds ratio:1.75,95% CI:1.42-2.12,P=0.25)..
    Conclusion
    The vacA gene alone could not be a reliable diagnostic marker for discriminating peptic ulcer disease from non-ulcer dyspepsia in the Iranian population under study.
    Keywords: Peptic Ulcer Disease, Non, ulcer Dyspepsia, Vaculating Cytotoxin A (vacA) Gene, Vaculating Cytotoxic Protein (VacA)
  • Zahra Khoshkam, Mahboobeh Zarrabi, Zargham Sepehrizade, Maryam Keshavarzi Pages 38-44
    Background
    Searching for the potent natural antibiotics will improve the treatment of most infectious diseases. Cyclotides are potent active peptides derived from some plant families like Violaceae. Viola tricolor (the pansy) has been found to have numerous cyclotides. Nowadays cyclotides attract more attention for their antibacterial activities. The current research studied the antimicrobial properties of semi-purified cyclotides from V. tricolor.
    Methods
    Extraction and purification of cyclotides from Iranian Viola tricolor were performed by fractionation and solid phase extraction methods, and their antimicrobial effects were studied against several bacterial strains using diffusion assays. Also, attendance of cyclotide in the extract was verified by Tricine-SDS page and spectroscopic methods.
    Results
    Antimicrobial effects of semi-purified cyclotides and crude extracts resulted in the antibacterial activity potential of V. tricolor totally extracted samples against gram negative bacteria, E.coli and P. aeruginosa. However, there is need for optimizing the assay method and the culture media.
    Conclusion
    Viola tricolor as a remedy represents the antibacterial potential, which may not be unrelated to its cyclotide content although the effectiveness of cyclotides may also differ because of their synergism, natural structure and bioactivities, the amount of purified content, and the way they were assayed.
    Keywords: Viola tricolor, Cyclotide, extraction, Antibacterial effect
  • Mohammad Sadegh Madadi, Mohammad Hassanzadeh, Fateme Karimnezhad Pages 45-47
    Background
    Young chickens are more susceptible to Salmonella colonization than older ones that have developed resistance with age as native microflora become established.
    Methods
    In this study, two groups of fertile eggs were inoculated with 20 CFU of hilA or parent strains of S. enteritidis. Presence and number of Salmonella cells inside the homogenized egg contents were determined on the 2nd, 5th, 8th, 12th, 17th and 21th day of incubation period.
    Results
    High infectivity rate of Salmonella contamination were observed in the hilA group eggs, three genes for S. enteritidis identification were detected from isolated colonies of both groups of eggs. The gene hilA was only detected in isolated colonies of the standard group.
    Conclusion
    These findings indicated that hilA mutant of Salmonella is able to rapidly multiply much higher than wild-type strain but, support more pathogenicity of wild-type strain of Salmonella compared to mutant strain.
    Keywords: Salmonella enteritidis, hilA, fertile eggs
  • Mohammad Mohammadzadeh, Mahnaz Tavakoli, Abolfazl Mohebi, Samad Aghayi Pages 48-54
    Background
    Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined.
    Methods
    In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes.
    Results
    Among 864 isolates, 62 (7.17 %) were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%), of which 24 (17.1%) and 16 (9.2%) isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4%) of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity.
    Conclusion
    The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.
    Keywords: Gram negative bacteria, Metallo beta lactamase, Imipenem