فهرست مطالب
Jundishapur Journal of Microbiology
Volume:9 Issue: 11, Nov 2016
- تاریخ انتشار: 1395/08/24
- تعداد عناوین: 11
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Page 1BackgroundCandida albicans is a commensal fungus that resides on mucosal surfaces and in the gastrointestinal and genitourinary tracts in humans. However, it can cause an infection when the immune system of the host is impaired or if a niche becomes available. Many C. albicans infections are due to the organisms ability to form a biofilm on implanted medical devices. A biofilm represents an optimal medium for the growth of C. albicans as it allows cells to be enclosed by a self-produced extracellular matrix (ECM)..ObjectivesThe present work investigated certain aspects of the resistance of C. albicans biofilms to drugs and the host immune system..ResultsAn ECM was found to provide the infrastructure for biofilm formation, prevent disaggregation, and shield encapsulated C. albicans cells from antifungal drugs and the hosts immune system. By influencing FKS1 and upregulating multiple glucan modification genes, β-1, 3-glucan, an important component of ECM, was shown to be responsible for many of the biofilms drug-resistant properties. On being engulfed by ECM, the fungal cell was found to switch from glycolysis to gluconeogenesis. Resembling the cellular response to starvation, this was followed by the activation of the glyoxylate cycle that allowed the use of simple molecules as energy sources..ConclusionMature biofilms were found to be much more resistant to antifungal agents and the host immune system than free cells. The factors responsible for high resistance included the complex architecture of biofilms, ECM, increased expression of drug efflux pumps, and metabolic plasticity..Keywords: Biofilms, Glucans, Fungal Drug Resistance, Arsenite Transporting ATPases, Candida albicans
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Page 2BackgroundResistant Pseudomonas aeruginosa is a serious concern for antimicrobial therapy, as the common isolates exhibit variable grades of resistance, involving beta-lactamase enzymes, beside native defense mechanisms..ObjectivesThe present study was designed to determine the occurrence of Metallo-β- Lactamases (MBL) and Amp C harboring P. aeruginosa isolates from Suez Canal university hospital in Ismailia, Egypt..MethodsA total of 147 P. aeruginosa isolates, recovered from 311 patients during a 10-month period, were collected between May 2013 and February 2014; the isolates were collected from urine, wound and sputum. Minimum inhibitory concentration (MIC) determined by agar dilution methods was ≥2 μg/mL for meropenem and imipenem. Identification of P. aeruginosa was confirmed using API 20NE. Metallo-β- Lactamases and Amp C were detected based on different phenotypic methods..ResultsOverall, 26.5% of P. aeruginosa isolates (39/147) were carbapenem resistant isolates. Furthermore, 64.1% (25/39) were MBL producers, these isolates were screened by the combined disc and disc diffusion methods to determine the ability of MBL production. Both MBL and Amp C harbored P. aeruginosa isolates were 28% (7/25). Sixty-four percent of P. aeruginosa isolates were multidrug resistant (MDR) (16/25). The sensitivity toward polymyxin, imipenem, norfloxacin, piperacillin-tazobactam and gentamicin was 99%, 91%, 88%, 82% and 78%, respectively. The resistance rate towards cefotaxime, ceftazidime, cefepime, aztreonam and meropenem was 98.6%, 86%, 71.4%, 34% and 30%, respectively..ConclusionsMultidrug resistance was significantly associated with MBL production in P. aeruginosa. Early detection of MBL-producing P. aeruginosa and hospital antibiotic policy prescription helps proper antimicrobial therapy and avoidance of dissemination of these multidrug resistance isolates..Keywords: Pseudomonas aeruginosa, MBLs, Amp C, MDR
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Page 3BackgroundLung cancer is one of the most common causes of death worldwide. Although smoking and environmental pollutants are the most important risk factors of lung cancer, the role of infectious causes should also be considered in the pathogenesis and progress of lung cancer..ObjectivesThis study examined the relationship between Helicobacter pylori and lung cancer through serology, real-time PCR, and urease tests..MethodsThis descriptive cross-sectional study was conducted on 52 adult patients with lung cancer who were selected after having their history taken and being physically examined by a pulmonologist. Then, the patients underwent a bronchoscopy, a BAL, and biopsy sampling. A urease test was run for each biopsy sample, real-time PCR was used for each BAL sample, and H. pylori serology was used for each patients serum..ResultsThe patients average age was 60.65 ± 9.15 years; 11.5% were female and 88.5% were male. The prevalence of H. pylori in lung cancer patients was 11.5% according to the BAL PCR test, 92.3% according to the serology test, and 3.8% according to the urease test..ConclusionsThe results demonstrated an association between of lung cancer and H. Pylori infection via the hypothesis of direct damage and chronic inflammation through inhalation and aspiration and the systematic immune response induced by H. pylori colonization. Helicobacter pylori, together with a hosts genetic predisposition and other environmental risk factors, could be attributed to the induction of lung cancer..Keywords: Helicobacter pylori, Pulmonary Neoplasm, Real, Time PCR
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Page 4BackgroundThe present study was undertaken to analyze the phytochemical content and biological activity of Cichorium intybus seeds traditionally used in Charsadda, Pakistan against multidrug resistant (MDR) bacterial pathogens..ObjectivesThis study explored the qualitative and quantitative antibacterial potential of C. intybus. Further qualitative analysis of phytochemical content was performed..MethodsCichorium intybus seed extracts were prepared in aqueous, chloroform, ethanol, and hexane separately..ResultsAll the extracts of C. intybus seeds were screened for antibacterial activity and phytochemical content. Cichorium intybus seed extract showed considerable activity against MDR pathogenic bacteria. In the well diffusion method, aqueous extracts showed a higher zone of inhibition against Pseudomonas aeruginosa (16 mm ± 0.7 mm) and Acinetobacter baumannii (13 mm ± 0.5 mm), whereas chloroform, ethanol, and hexane extracts showed activity against P. aeruginosa (11 mm ± 0.3 mm, 12 mm ± 0.5 mm, and 11 mm ± 0 mm, respectively) as compared to Imipenem, a broad spectrum antibiotic. Minimum inhibitory concentration and minimum bactericidal concentration values for aqueous and ethanol extracts indicate that they were more effective against MDR bacteria. Phytochemical analysis revealed that aqueous and ethanol extracts were rich in alkaloids, carbohydrates, gallotannins, and triterpenoids, whereas chloroform and hexane extracts were more concentrated with phenolics, pseudotannins, saponins, and tannins. Cichorium intybus seed extract demonstrated potential activity against MDR human pathogenic bacteria..ConclusionsThe undertaken study has for the first time reported the effects of C. intybus seed extracts against MDR bacterial pathogens. Findings of the current study will be helpful for further elucidation of bioactive molecules for therapeutic use against MDR bacterial pathogens..Keywords: Cichorium Intybus Seed Extract, Antibacterial Activity, MIC, MBC, Phytochemical Analysis
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Page 5BackgroundAcanthamoeba spp. is a free-living opportunistic protozoan parasites, which can be found in tap, fresh and bottled mineral waters, contact lens solutions, soil etc..ObjectivesThe present study is aimed to determine the Acanthamoeba spp. on the basis of their morpho-molecular aspects in different water sources of the West Azerbaijan province, Northwest of Iran..MethodsIn this cross-sectional study, 60 water samples were collected from rivers and tap waters during June to September 2015. The water samples were filtered through a cellulose nitrate filter and cultured on non-nutrient agar medium. The extracted DNAs were amplified and some ampliqons were sequenced using partial 18S rRNA for genotyping and phylogenetic analyses..ResultsTwenty-seven (45%) out of 60 water samples were positive to Acanthamoeba spp. using both culture and morphological examinations. In addition, 24 (40%) out of 27 positive samples in culture method were confirmed by PCR to be Acanthamoeba spp..ConclusionsA relatively high prevalence of Acanthamoeba spp. in rivers reflects a risk alert for threatening human health in the region. However, well hygienic status of the tap waters considering Acanthamoeba spp. cannot be ignored in western co-border regions of Iran-Iraq. This study can also serve as a platform for further explorations of water sources in Iran and neighboring countries..Keywords: West Azerbaijan, Water resources, PCR, Iran, Acanthamoeba
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Page 6BackgroundThe hepatitis E virus (HEV) accounts for hepatitis E infection with relatively high mortality rate in pregnant women that can lead to fulminant hepatitis. The baculovirus expression system (BES) has the capability to produce high-level recombinant proteins and could be useful for vaccine designing..ObjectivesThe aim of this study was designing a recombinant hepatitis E virus ORF2 and Rotavirus NSP4 (ORF2-NSP4) and to evaluating construction these recombinant proteins in the BES..MethodsThe truncated ORF2 gene (112-607) and truncated ORF2-NSP4 were subcloned in pFastBac1 plasmid, separately, followed by digestion and confirmed by digestion and sequencing. Then the products were transformed into Escherichia coli DH5α and retransformed in DH10Bac competent cells. Finally the white colonies containing Bacmid DNA subjected to PCR for confirming transformation. Bacmid DNA containing HEV truncated ORF2 and HEV truncated ORF2-NSP4 genes were transfected into SF9 cells using BES. The expressed proteins in the cell lysate were evaluated by SDS-PAGE and determined by the western blot assay..ResultsThe lengths of the subcloned genes, truncated ORF2 and truncated ORF2-NSP4 were 1500 and 2000bp, respectively. After retransforming in DH10Bac, the size of PCR products were 300 bp in Bacmid DNA without recombination while it was 4300 and 3800 bp in Bacmid truncated ORF2-NSP4 and Bacmid truncated ORF2 PCR products. The analysis of protein expression by SDS-PAGE and immunoblotting revealed the presence of 56 KDa for truncated ORF2 and 74.5 KDa for truncated ORF2-NSP4 proteins..ConclusionsThe results of the present study showed that the baculovirus expression system (SF9 cells) was able to express truncated ORF2 and truncated ORF2-NSP4 proteins as a potential candidate vaccine..Keywords: HEV ORF2, NSP4 Protein, Rotavirus, pFastBac1, sf9 Cell
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Page 7BackgroundA common mechanism of resistance to beta-lactam antibiotics is the production of beta-lactamase by Gram-negative bacteria. Recently, nonderivative extended-spectrum beta-lactamases (ESBLs) from the TEM and SHV enzymes, such as CTX-M, that were related to different geographical regions have been recognized..ObjectivesThe aim of this study was to determine the frequency of the CTX-M gene in ESBL-producing Enterobacteriaceae isolates in hospitalized patients in the teaching hospitals of Ahvaz, Iran..MethodsEnterobacteriaceae isolates from clinical specimens (other than stool), such as wounds, blood, urine, trachea, discharge, and abscess, were collected and examined. All the isolates were identified using standard biochemical tests. The combination test was carried out based on CLSI criteria for the phenotypic detection of ESBL-producing isolates. After DNA extraction, the CTX-M and CTX-M-1 genes were amplified using PCR among phenotypically positive ESBL isolates..ResultsAmong 240 Enterobacteriaceae isolates, Escherichia coli and Enterobacter were the most common isolates with 171 (71.3%) and 65 (27.1%), respectively. The combination test results also showed that 108 (45%) Enterobacteriaceae isolates were phenotypic ESBL producers, but 104 (96%) isolates were positive for the blaCTX-M gene and 99 (92%) were positive for the blaCTX-M-1 gene according to the PCR method..ConclusionsThe results of this study phenotypically and genotypically confirmed the high frequency of ESBL-producing strains, such as the CTX-M and CTX-M-1 genes, among Enterobacteriaceae isolates in our region. Therefore, use of antibiotic susceptibility testing for the detection of ESBL isolates prior to the prescription of beta-lactam antibiotics is recommended. This could help prevent the spread of bacteria strains that are resistant to beta-lactam antibiotics..Keywords: Extended, Spectrum Beta, Lactamase, Polymerase Chain Reaction, CTX, M, Enterobacteriaceae
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Page 8BackgroundGiardia lamblia is a common intestinal parasite that has been reported all over the world..ObjectivesThis study was conducted to evaluate the effect of ozonized organic extra-virgin olive oil on the cyst of G. lamblia..MethodsThe olive oil was ozonized based on international standards and confirmed by the world health organization (WHO) at various times in a generator. The ozone concentration of olive oil was adjusted at 32, 64, 96, 128, 160 mg/g based on ozone absorption. Giardia lamblia cysts were isolated from heavily infected stool samples and the sucrose gradient flotation technique. Five groups of triple tubes containing Giardia cysts were exposed to olive oil with 32, 64, 96, 128, 160 ozone concentrations, and the sixth and seventh groups were exposed to non-ozonized olive oil and normal saline, respectively. The tubes were placed at room temperature, and every four hours, the mortality of the Giardia cysts was assessed..ResultsThe results showed that the first five groups mortality rate of Giardia cysts reached 100% in 100 hours. An increasing concentration of ozone in olive oil leads to an increase in the mortality rate of Giardia cysts. The results showed a significant difference in the mean time of the mortality in all the groups (P ≤ 0.05). Furthermore, the higher fatality effect of ozonized organic extra-virgin olive oil (Ozonized Olive Oil = OZO) was proved in comparison with metronidazole in vitro..ConclusionsWe concluded that ozonized organic extra-virgin olive oil was a growth inhibitor of Giardia cysts, and concerning its compatibility with a biological system, it is recommended for further clinical trials..Keywords: Complementary Therapies, Ozonized Olive Oil, Olive Plant, Ozone, Giardia lamblia
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Page 9BackgroundNeutropenia, as a predisposing factor for invasive candidiasis, is defined as a reduction in neutrophil count to less than 1500/mm3. It is a common condition in patients with hematological malignancy and cytostatic chemotherapy. Extensive chemotherapy and prophylaxis with antifungals have increased the resistance of Candida isolates to antifungal drugs. Although, Candida albicans is the most common causative agent among neutropenic patients, there is an increasing rate of non-albicans species. Extracellular enzymes activity pattern and antifungal agent sensitivity profiles are two important factors for spreading resistant strains..ObjectivesThe aim of the present study was to identify the Candida strains isolated from hospitalized neutropenic patients. The patterns of antifungal susceptibility of the causative agents to antifungals and the extracellular enzymes activity of the isolates were also evaluated..
Patients andMethodsIn the present study, 243 urine and 243 oral swab samples were collected from neutropenic patients and inoculated on CHROMagar Candida. In addition, 100 blood samples were also inoculated in biphasic Brain Heart Infusion medium. Several yeast isolates were isolated from samples and identified by classical and molecular techniques. The profiles of extracellular enzymes and the susceptibility of recovered agents to amphotericin B, fluconazole and caspofungin were also evaluated..ResultsA total of 110 yeast strains isolated from urine and oral cavities were identified as C. albicans (51.8%), C. krusei (25.5%), C. glabrata (6.4%) and other yeasts (16.3%). No yeast species was isolated from blood samples. Our result showed that in 90% of the isolates, the range of secretion of extracellular enzymes was medium (2) and high (3), however only a few isolates were negative for this characteristic. All isolates were sensitive to caspofungin and fluconazole, whereas 54.7% of isolates were resistant to amphotericin B..ConclusionsWe found a marked increase in the incidence of non-albicans species (48.2%) among neutropenic patients. Only a few strains failed to produce extracellular enzymes. Finally, in addition to fluconazole, caspofungin can be considered as the first line treatment against Candida species among neutropenic patients..Keywords: Neutropenic Patients, Antifungal Susceptibility, Extracellular Enzymes, Candida -
Page 10BackgroundInvasive fungal infection (IFIs) is a major infectious complication in immunocompromised patients. Early diagnosis and initiation of antifungal therapy is important to achieve the best outcome..ObjectivesThe current study aimed to investigate the incidence of IFIs and evaluate the diagnostic performance of non-invasive laboratory tests: serologic (β-D-glucan, galactomannan) and molecular (nested polymerase chain reaction) tests to diagnose fungal infections in hematologic pediatric patients..
Patients andMethodsIn a cross-sectional study from October 2014 to January 2015, 321 blood samples of 62 pediatric patients with hematologic disorders and at high risk for fungal infections were analyzed. Non-invasive tests including the Platelia Aspergillus enzyme immunoassay (EIA) to detect galactomannan antigen, Glucatell for βDglucan and nested PCR to detect Candida and Aspergillus species-specific DNA were used in a weekly screening strategy..ResultsTwenty six patients (42%) were considered as proven and probable IFIs, including 3 (5%) proven and 23 (37%) probable cases. Eighteen patients (29%) were considered as possible cases. The sensitivity, specificity, positive and negative predictive values for galactomannan test in 26 patients with proven and probable fungal infections were 94.4%, 100%, 100% and 94.7%; for β-D-glucan test 92.3%, 77.7%, 85%, 87.5% and for nested-PCR were 84.6%, 88.8%, 91.7% and 80%, respectively..ConclusionsThe rate of IFIs in pediatric patients with hematologic disorders is high, and sample collection from the sterile sites cannot be performed in immunocompromised patients. Detection of circulating fungal cell wall components and DNA in the blood using non-invasive methods can offer diagnostic help in patients with suspected IFIs. Their results should be interpreted in combination with clinical, radiological and microbiological findings..Keywords: β D, Glucan, Galactomannan, Invasive Fungal Infections, Nested, PCR, Pediatric Patients with Hematologic Disorders