Jundishapur Journal of Microbiology
Year:2016 | Volume:9 | Issue:11|Papers Count:10

Background: A 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. Objectives: The 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. Methods: Enterobacteriaceae 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. Results: Among 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. Conclusions: The 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.

Background: Resistant 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. Objectives: The present study was designed to determine the occurrence of Metallo--Lactamases (MBL) and Amp C harboring P. aeruginosa isolates from Suez Canal university hospital in Ismailia, Egypt. Methods: A 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  g/mL for meropenem and imipenem. Identification of P. aeruginosa was confirmed using API 20NE. Metallo--Lactamases and Amp C were detected based on different phenotypic methods. Results: Overall, 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 andAmpC 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. Conclusions: Multidrug resistance was significantly associated with MBL production in P. aeruginosa. Early detection of MBLproducing P. aeruginosa and hospital antibiotic policy prescription helps proper antimicrobial therapy and avoidance of dissemination of these multidrug resistance isolates.

Background: Neutropenia, 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. Objectives: The 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 and Methods: In 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. Results: A 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. Conclusions: We 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.

Background: Candida 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 organism’ s 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). Objectives: The present work investigated certain aspects of the resistance of C. albicans biofilms to drugs and the host immune system. Results: An ECM was found to provide the infrastructure for biofilm formation, prevent disaggregation, and shield encapsulated C. albicans cells from antifungal drugs and the host’ s immune system. By influencing FKS1 and upregulating multiple glucan modification genes, -1, 3-glucan, an important component of ECM, was shown to be responsible for many of the biofilm’ s 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. Conclusion: Mature 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.

Background: Lungcancer isoneof themostcommoncauses of death worldwide. Althoughsmokingandenvironmental 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. Objectives: This study examined the relationship between Helicobacter pylori and lung cancer through serology, real-time PCR, and urease tests. Methods: This descriptive cross-sectional study was conducted on 52 adult patients with lung cancerwhowere 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 patient’ s serum. Results: The 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. Conclusions: The 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 host’ s genetic predisposition and other environmental risk factors, could be attributed to the induction of lung cancer.

Background: The 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. Objectives: This study explored the qualitative and quantitative antibacterial potential of C. intybus. Further qualitative analysis of phytochemical content was performed. Methods: Cichorium intybus seed extracts were prepared in aqueous, chloroform, ethanol, and hexane separately. Results: All the extracts of C. intybus seeds were screened for antibacterial activity and phytochemical content. Cichorium intybus seed extract showed considerable activity against MDRpathogenic 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. Conclusions: The 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.

Dear Editor, Recently, we read with interest the case report by Sharif et al. entitled “ Streptococcal pharyngitis in a two-month-old infant: a case report” published in Jundishapur journal of microbiology (1). Streptococcal pharyngitis, as reported in their manuscript, is rare among children less than 1 year old and there are no clear instructions regarding the treatment of infant patients suffering from this condition. The main goals of antimicrobial therapy for eradication of group A beta-hemolytic streptococcus (GABHS) pharyngitis are reducing severity and duration of acute signs and symptoms, lowering the incidence of nonsuppurative complications and reducing the transmission rat (2). In this case the patient has been treated with intramuscular penicillin benzathine G because of poor feeding and significant illness; however, this is not the only treatment choice (1). Antimicrobial resistance has not been a significant issue in the treatment of GABHS pharyngitis and several treatment options are available (3, 4)...

Background: The 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. Objectives: The 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. Methods: The 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 DH5 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. Results: The 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. Conclusions: The 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.

Background: Acanthamoeba spp. is a free-living opportunistic protozoan parasites, which can be found in tap, fresh and bottled mineral waters, contact lens solutions, soil etc. Objectives: The present study is aimed to determine the Acanthamoeba spp. on the basis of their morpho-molecular aspects in different water sources of theWest Azerbaijan province, Northwest of Iran. Methods: In 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. Results: Twenty-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. Conclusions: A 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.

Background: Invasive 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. Objectives: The current study aimed to investigate the incidence of IFIs and evaluate the diagnostic performance of non-invasive laboratory tests: serologic (-D-glucan, galactomannan) and molecular (nested polymerase chain reaction) tests to diagnose fungal infections in hematologic pediatric patients. Patients and Methods: In 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  – D– glucan and nested PCR to detect Candida and Aspergillus species-specific DNA were used in a weekly screening strategy. Results: Twenty 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 -D-glucan test 92. 3%, 77. 7%, 85%, 87. 5% and for nested-PCR were 84. 6%, 88. 8%, 91. 7% and 80%, respectively. Conclusions: The 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 andDNAin 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.