فهرست مطالب

Jundishapur Journal of Microbiology - Volume:9 Issue: 7, 2016
  • Volume:9 Issue: 7, 2016
  • تاریخ انتشار: 1395/06/02
  • تعداد عناوین: 11
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  • Sadegh Khodavaisy, Sassan Rezaie, Fatemeh Noorbakhsh, Elham Baghdadi, Somayeh Sharifynia, Farzad Aala* Page 1
    Background
    Aflatoxins are highly toxic secondary metabolites mainly produced by Aspergillus parasiticus. This species can contaminate a wide range of agricultural commodities, including cereals, peanuts, and crops in the field. In recent years, research on medicinal herbs, such as Pistacia atlantica subsp. kurdica, have led to reduced microbial growth, and these herbs also have a particular effect on the production of aflatoxins as carcinogenic compounds.
    Objectives
    In this study, we to examine P. atlantica subsp. kurdica as a natural compound used to inhibit the growth of A. parasiticus and to act as an anti-mycotoxin.
    Materials And Methods
    In vitro antifungal susceptibility testing of P. atlantica subsp. kurdica for A. parasiticus was performed according to CLSI document M38-A2. The rate of aflatoxin production was determined using the HPLC technique after exposure to different concentrations (62.5 - 125 mg/mL) of the gum. The changes in expression levels of the aflR gene were analyzed with a quantitative real-time PCR assay.
    Results
    The results showed that P. atlantica subsp. kurdica can inhibit A. parasiticus growth at a concentration of 125 mg/mL. HPLC results revealed a significant decrease in aflatoxin production with 125 mg/mL of P. atlantica subsp. kurdica, and AFL-B1 production was entirely inhibited. Based on quantitative real-time PCR results, the rate of aflR gene expression was significantly decreased after treatment with P. atlantica subsp. kurdica.
    Conclusions
    Pistacia atlantica subsp. kurdica has anti-toxic properties in addition to an inhibitory effect on A. parasiticus growth, and is able to decrease aflatoxin production effectively in a dose-dependent manner. Therefore, this herbal extract maybe considered a potential anti-mycotoxin agent in medicine or industrial agriculture.
    Keywords: HPLC, Real, Time PCR, Aflatoxin, Aspergillus parasiticus, Pistacia atlantica subsp. Kurdica
  • Mohammad Zarei, Mehrdad Ravanshad, Ashraf Bagban*, Shahab Fallahi Page 2
    Background
    The human immunodeficiency virus (HIV-1) is the etiologic agent of AIDS. The disease can be transmitted via blood in the window period prior to the development of antibodies to the disease. Thus, an appropriate method for the detection of HIV-1 during this window period is very important.
    Objectives
    This descriptive study proposes a sensitive, efficient, inexpensive, and easy method to detect HIV-1.
    Patients and
    Methods
    In this study 25 serum samples of patients under treatment and also 10 positive and 10 negative control samples were studied. Twenty-five blood samples were obtained from HIV-1-infected individuals who were receiving treatment at the acquired immune deficiency syndrome (AIDS) research center of Imam Khomeini hospital in Tehran. The identification of HIV-1-positive samples was done by using reverse transcription to produce copy deoxyribonucleic acid (cDNA) and then optimizing the nested polymerase chain reaction (PCR) method. Two pairs of primers were then designed specifically for the protease gene fragment of the nested real time-PCR (RT-PCR) samples. Electrophoresis was used to examine the PCR products. The results were analyzed using statistical tests, including Fisher’s exact test, and SPSS17 software.
    Results
    The 325 bp band of the protease gene was observed in all the positive control samples and in none of the negative control samples. The proposed method correctly identified HIV-1 in 23 of the 25 samples.
    Conclusions
    These results suggest that, in comparison with viral cultures, antibody detection by enzyme linked immunosorbent assay (ELISAs), and conventional PCR methods, the proposed method has high sensitivity and specificity for the detection of HIV-1.
    Keywords: HIV, 1, Nested PCR, HIV Protease
  • Samaneh Abbasi, Manoochehr Makvandi*, Gharib Karimi, Niloofar Neisi Page 3
    Background
    The SEN virus (SENV) is a prevalent blood borne pathogen that has a worldwide incidence. SENV is comprised of eight genotypes; genotypes H and D are frequently associated with the pathogenesis of non-A - E hepatitis and post-transfusion hepatitis in blood donors and hepatitis patients. So far, no SENV pathogenesis has been reported in the liver biopsies of SENV carriers, but the frequency of SENV and its related genotypes requires further molecular epidemiology studies in different regions of the world. Occult hepatitis B infection (OBI) is another global public health problem that is primarily transmitted via blood transfusions. Therefore, the identification of OBI among blood donors is key to preventing the spread of this disease. The relationship between SENV and OBI requires further evaluation.
    Objectives
    The aim of this study was to determine the prevalence of SENV-D and SENV-H in blood donors in Ahvaz city with a particular focus on co-infection with OBI.
    Patients and
    Methods
    This study had a cross-sectional design and included 184 healthy consecutive blood donors who visited a blood transfusion center in Ahvaz city from October-November 2013. The sera of all blood donors negative for HBsAg, anti-HCV antibody, and anti-HIV antibody were tested for SENV-D and SENV-H using nested polymerase chain reaction (PCR). In addition, tests for HBV DNA (PCR), HBcIgG (ELISA), liver function (aspartate transaminase and alanine transaminase), and alkaline phosphatase were carried out.
    Results
    Liver function tests in the healthy blood donors were within the normal range. The incidence rates of SENV-D and SENV-H in the 184 total blood donors were 10 (5.4%) (95% confidence interval (CI): 2.1% - 9.0%) and 32 (17.4%) cases (95% CI: 12.0% - 23.0%), respectively. SENV-H/D co-infection occurred in 2 (1.1%) patients. The sera of 8/184 (4.3%) were positive for anti-HBc antibody but negative for HBV DNA.
    Conclusions
    Regardless of the presence of nonpathogenic SENV, 44/184 (24%) blood donors tested positive for both SENV-D and SENV-H. Although 4.3% of blood donors were positive for HBcIgG but negative for HBV DNA, the presence of OBI cannot be ruled out unless their liver biopsies show negative for HBV DNA.
    Keywords: SEN Virus_Chronic Hepatitis B Infection_Transfusion Transmitted Virus_Blood Donor_Polymerase Chain Reaction
  • Mehdi Goudarzi, Maryam Fazeli, Hossein Goudarzi, Mehdi Azad, Sima Sadat Seyedjavadi* Page 4
    Background
    The incidence of nosocomial Staphylococcus aureus infection is increasing annually and becoming a true global challenge. The pattern of Staphylococcus aureus protein A (spa) types in different geographic regions is diverse.
    Objectives
    This study determined the prevalence of methicillin-resistant S. aureus and different spa types in S. aureus clinical isolates.
    Materials And Methods
    During a six-month period, 90 S. aureus isolates were recovered from 320 clinical specimens. The in vitro susceptibility of various S. aureus isolates to 16 antibiotic discs was assessed using the Kirby-Bauer disk diffusion method. Molecular typing was carried out with S. aureus protein A typing via polymerase chain reaction.
    Results
    The frequency of methicillin-resistant S. aureus in our study was 88.9%. Twenty-three (25.5%) isolates were positive for panton-valentine leukocidin encoding genes. S. aureus presented a high resistance rate to ampicillin (100%) and penicillin (100%). No resistance was observed to vancomycin, teicoplanin, or linezolid. The rates of resistance to the majority of antibiotics tested varied between 23.3% and 82.2%. The rate of multidrug resistance among these clinical isolates was 93.3%. The 90 S. aureus isolates were classified into five S. aureus protein A types: t037 (33.3%), t030 (22.2%), t790 (16.7%), t969 (11.1%), and t044 (7.7%). Eight (8.9%) isolates were not typable using the S. aureus protein A typing method.
    Conclusions
    We report a high methicillin-resistant S. aureus rate in our hospital. Additionally, t030 and t037 were the predominant spa-types among hospital-associated S. aureus. Our findings emphasize the need for continuous surveillance to prevent the dissemination of multidrug resistance among different S. aureus protein A types in Iran.
    Keywords: Spa Typing, Nosocomial Infection Staphylococcus aureus, Methicillin, Resistant Staphylococcus aureus (MRSA)
  • Mohammad Taghi Hedayati, Saeid Mahdavi Omran*, Abbas Soleymani, Mojtaba Taghizadeh Armaki Page 5
    Context: Mycotoxins are secondary metabolites produced by certain toxigenic fungi and the most of them are aflatoxins, fumonisins, trichothecenes, ochratoxin A, patulin, and zearalenone.
    Evidence Acquisition: In consideration of the consumption of certain farm products for animal feed and the prevalence of toxigenic fungi and mycotoxins in food, the present study was performed to evaluate this situation in Iran with a review of the literature using search engines. All published articles were selected using Iran Medex, Magiran, PubMed NCBI, and Google Scholar.
    Results
    Aflatoxins have been found in many food products in Iran.
    Conclusions
    It is necessary to detect aflatoxins in foods and food products as early as possible, before they enter human or animal bodies. There is a high consumption of milk and dairy products in Iran, and the proper management of animal foods can help to decrease the aflatoxins in milk.
    Keywords: Aflatoxin, Foods, Iran
  • Jayanta Kumar Patra, Kwang, Hyun Baek* Page 6
    Background
    Listeria monocytogenes is one of the most virulent types of bacteria and causes severe foodborne illness, such as listeriosis. Because this pathogen has become resistant to sanitizers and other disinfectants that are used to clean utensils and surfaces during food processing, it poses a serious threat to the food industry.
    Objectives
    The study was conducted to determine the anti-listerial potential of essential oils extracted from four edible seaweeds against L. monocytogenes.
    Materials And Methods
    Essential oil was extracted from four edible seaweeds (Enteromorpha linza, Undaria pinnatifida, Laminaria japonica, and Porphyra tenera) against L. monocytogenes using the microwave hydrodistillation method. The anti-listerial activity of the essential oil was determined using the standard disc diffusion method.
    Results
    Among the four essential oils, E. linza (ELEO) was most effective against all three strains of L. monocytogenes (11.3 - 16.0 mm). The other three essential oils were only effective against two strains, L. monocytogenes ATCC 19115 (10.0 - 10.5 mm) and L. monocytogenes ATCC 7644 (11.0 - 15.0 mm). The minimum inhibitory concentration and the minimum bactericidal concentration of all four essential oils varied from 12.5 - 25.0 mg/mL. Further, the mode of action of ELEO against L. monocytogenes was investigated by examining its effect on cell viability, the release of 260-nm absorbing materials, the number of K ions, the relative electrical conductivity, and the salt tolerance capacity. The results indicated that the essential oils exhibited strong anti-listerial activity against multiple strains of L. monocytogenes. It displayed potential inhibitory effects on the viability of bacterial cells and loss of integrity as indicated by an increase in the relative electrical conductivity, leakage of K ions and other 260-nm absorbing materials, and a loss of the salt tolerance capacity.
    Conclusions
    The results presented herein provided insight into a possible explanation for the modes of action of essential oils on L. monocytogenes. The outcome of the present study may aid the food industry in locating the most promising potential anti-listerial agents from edible seaweed sources to control L. monocytogenes and also in facilitating their application in food processing and preservation techniques in a nontoxic and environmental friendly manner.
    Keywords: Antibacterial Agents, Cell Membrane Permeability, Essential Oil, Salt, Tolerant
  • Cai, Xia Liu, Chun Yan, Pan Zhang, Fang, Qu Li, Jing, Hong Yang, Xiang, Yang Li* Page 7
    Background
    Ralstonia mannitolilytica is an emerging opportunistic pathogen. Hospital outbreaks of Ralstonia spp. are mainly associated with contaminated treatment water or auxiliary instruments.
    Objectives
    In this report, we summarize the clinical infection characteristics of R. mannitolilytica, the drug-susceptibility testing of the bacterial strains, and the results of related infection investigations.
    Patients and
    Methods
    We retrospectively analyzed the clinical information of 3 patients with R. mannitolilytica.
    Results
    The patients’ primary-onset symptoms were chills and fever. The disease progressed rapidly and septic shock symptoms developed. Laboratory tests indicated progressively decreased white blood cells and platelets, as well as significant increases in certain inflammation indicators. The effect of treatment with Tazocin was good. The growth period of R. mannitolilytica in sterile distilled water was > 6 months. The pulsed-field gel electrophoresis (PFGE) results revealed that the infectious strains from these 3 patients were not the same clonal strain. This bacterium was not detected in the nosocomial infection samples.
    Conclusions
    Our results suggest that R. mannitolilytica-induced septicemia had an acute disease onset and rapid progression. The preferred empirical antibiotic was Tazocin. In these 3 cases, the R. mannitolilytica-induced septicemia was not due to clonal transmission.
    Keywords: Drug Susceptibility, Pulsed, Field Gel Electrophoresis, Septicemia, Nosocomial Infection, Ralstonia mannitolilytica
  • Saeideh Najafi*, Masood Ghane, Vahdat Poortahmasebi, Seyed Mohammad Jazayeri, Shahrokh Yousefzadeh, Chabok Page 8
    Background
    Multiple sclerosis (MS) is a chronic debilitating disease known as one of the most common neurological dysfunctions in young adults. Recent studies suggest that infections with herpesviruses play a critical role in the pathogenesis of MS.
    Objectives
    The present investigation aimed to detect the presence of cytomegalovirus (CMV) in patients with MS using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) methods.
    Patients and
    Methods
    Plasma and peripheral blood mononuclear cells (PBMCs) were collected from MS patients (n = 82) and from blood donors as control group (n = 89). They were tested for the presence of CMV antibodies and DNA by ELISA and PCR, respectively.
    Results
    Anti-CMV was positive in 65 (79.3%) and 69 (77.5%) of the MS patients and healthy subjects, respectively (P= 0.853). Similarly, 23 (28%) and 2 (2.2%) patients were positive for CMV DNA among the MS and control groups, respectively. Statistical analysis showed that the frequency of CMV DNA in the MS patients was significantly higher than in the healthy controls (P
    Conclusions
    The results of this study showed a possible association between CMV infection and MS. Further experimental and epidemiological studies using case-control approaches are needed to confirm this association.
    Keywords: Multiple Sclerosis, Cytomegalovirus, Autoimmune Disease
  • Sajjad Ahmad*, Faisal Ahmad, Faiz Ur Rahman, Salman Khan, Waheed Murad, Imran Mughal, Amjad Ur Rahman, Fida Muhammad Khan, Imad Khan, Hajra Ahmad Page 9
    Background
    The distribution pattern of phase-variable genes varies from strain to strain and from region to region. The present study was carried out to investigate the distribution pattern of phase-variable genes within Pakistan-based Helicobacter pylori strains and to analyze and compare them with strains prevalent in other parts of the world.
    Objectives
    To determine the distribution pattern of phase-variable genes in H. pylori strains circulating in Pakistan.
    Patients and
    Methods
    Biopsy samples were collected from 85 symptomatic patients suffering from various upper gastrointestinal tract symptoms. The biopsy specimens were chopped, then inoculated on H. pylori-specific media and incubated in a Campylobacter Gas Generating kit. Positive isolates were further confirmed via staining and biochemical procedures. Primers were designed for five phase-variable genes using OligoCalc, an oligonucleotide properties calculator (version 3.26) according to parameters stipulated in the literature. Polymerase chain reaction (PCR) was performed on all positive isolates to determine the presence or absence of phase-variable genes.
    Results
    On culturing, the prevalence of H. pylori infections in the samples was 44.7%. The prevalence was higher in females than in males, and it increased with age. PCR amplification revealed that the hsdR gene was present in 79% of samples, while the mod and β-subunit genes were present in 16% and 30% of samples, respectively. The streptococcal M protein gene was found in 79%, while the fliP gene was prevalent in 56%.
    Conclusions
    The distribution patterns of phase-variable genes in Pakistani H. pylori strains were found to be somewhat different. The dominant prevalence of the hsdR gene was an interesting finding, considering its role in bacterial defense in both micro- and macroenvironments.
    Keywords: PCR, Phase, Variable Genes, Restriction Modification System, Helicobacter pylori
  • Elham Rezazadeh, Azar Sabokbar, Maryam Moazeni, Mohammad Sadegh Rezai, Hamid Badali* Page 10
    Background
    Candida species, as opportunistic organisms, can cause various clinical manifestations, ranging from mild cutaneous infections to systemic candidiasis in otherwise healthy individuals. Remarkably, the incidence and mortality rates of candidemia have significantly increased worldwide, even after advances in medical interventions and the development of novel antifungal drugs.
    Objectives
    Given the possible resistance to antifungal agents, susceptibility testing can be useful in defining the activity spectrum of antifungals and determining the appropriate treatment regime.
    Materials And Methods
    The in vitro susceptibilities of molecularly identified Candida strains (n = 150) belonging to seven species recovered from clinical specimens, including vaginal, cutaneous, sputum, bronchoalveolar lavage (BAL), and blood samples, were determined for six antifungal drugs (amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin), based on the clinical and laboratory standards institute’s M27-A3 and M27-S4 documents.
    Results
    Candida albicans was the most frequently isolated species (44.66%), followed by non-albicans Candida, including C. glabrata (20%), C. parapsilosis (13.33%), C. krusei (8%), C. tropicalis (7.3%), C. dubliniensis (4%), and C. africana (3.33%). Posaconazole had the lowest geometric mean minimum inhibitory concentration (MIC) (0.0122 µg/ml), followed by amphotericin B (0.0217 µg/mL), voriconazole (0.1022 µg/mL), itraconazole (0.1612 µg/mL), caspofungin (0.2525 µg/mL), and fluconazole (0.4874 µg/mL) against all isolated Candida species. Candida africana and C. parapsilosis were significantly more susceptible to fluconazole, compared to C. albicans and other Candida species (P
    Conclusions
    These findings highlight the importance of precise and correct species identification of clinical yeast isolates via molecular approaches, and of monitoring the antifungal susceptibility of Candida species recovered from clinical sources. Laboratories should consider routine MIC testing of C. glabrata isolates collected from sterile sites. Surveillance studies of Candida species and new analyses of antifungal treatment outcomes will allow more informed determinations of the value of these drugs in the antifungal armamentarium.
    Keywords: Candidiasis, Antifungal Susceptibility, Candida Species
  • Naser Mohammadpour Dounighi, Mehdi Razzaghi, Abyane, Mojtaba Nofeli, Hossein Zolfagharian, Fereshteh Shahcheraghi* Page 11
    Background
    Whooping cough is caused by Bordetella pertussis, and it remains a public health concern. Whole-cell pertussis vaccines have been commonly employed for expanded immunization. There is no doubt of the efficacy of whole cell pertussis vaccine, but it is necessary to improve the vaccine to decrease its toxicity.
    Objectives
    In this study, an inactivation process of dealing with pertussis bacteria is optimized in order to decrease the bacteria content in human doses of vaccines and reduce the vaccine’s toxicity.
    Materials And Methods
    The bacterial suspensions of pertussis strains 509 and 134 were divided into 21 sample parts from F1 to F21 and inactivated under different conditions. The inactivated suspensions of both strains were tested for opacity, non-viability, agglutination, purity, and sterility; the same formulation samples that passed quality tests were then pooled together. The pool of inactivated suspensions were analyzed for sterility, agglutination, opacity, specific toxicity, and potency.
    Results
    The harvest of both bacterial strains showed purity. The opacity of various samples were lost under different treatment conditions by heat from 8% to 12%, formaldehyde 6% to 8%, glutaraldehyde 6% to 8%, and thimerosal 5% to 8%. Tests on suspensions after inactivation and on pooled suspensions showed inactivation conditions not degraded agglutinins of both strains. The samples of F2, F4, F8, F12, F15, and F17 passed the toxicity test. The potency (ED50) of these samples showed following order F17 > F12 > F8 > F15, F4 > F2, and F17 revealed higher potency compared to other formulations.
    Conclusions
    It can be concluded that F17 showed desirable outcomes in the toxicity test and good immunogenicity with a low bacterial number content. Consequently, lower adverse effects and good immunogenicity are foreseeable for vaccine preparation with this method.
    Keywords: Whole, Cell Vaccines, Pertussis, Whooping Cough, Toxicity Test, Potency Test