Jundishapur Journal of Microbiology
Year:2018 | Volume:11 | Issue:2|Papers Count:9

Background: Tuberculosis (TB) is one of the most widespread and lethal infectious diseases worldwide. The emergence of drugresistant TB has hampered effective TB treatment and control. Prokaryotic ubiquitin-like Protein-Proteasome System (PPS) contributes to the survival of Mycobacterium tuberculosis in the host. However, whether PPS effects drug resistance of isoniazid monoresistant Mycobacterium tuberculosis (INH-MTB) is still unknown. Objectives: This study aimed at exploring the effect of PPS on drug resistance of INH-MTB strain. Methods: In this study, over-expression of strains and deletion of mutant strains were constructed using electroporation. The researchers identified these constructed strains by Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) or PCR. The Minimum Inhibitory Concentration (MIC) of isoniazid in INH-MTB strain and its derivative PPS mutant strains were determined using the Resazurin micro-titre assay. Results: The MIC of isoniazid was 8  g/mL higher in INH-MTB with Pup over-expression strain than that in INH-MTB. The MIC of isoniazid was 4. 82  g/mL, 4. 98  g/mL, 4. 99  g/mL, and 4. 9  g/mL lower in INH-MTB with deletion of Pup, Dop, PafA or Mpa strains than that in INH-MTB, respectively. The differences had statistical significance (P < 0. 05). The MIC of isoniazid was 1. 03 g/mL higher in INH-MTB with PafA over-expression strain than that in INH-MTB. The MIC of isoniazid was 1. 03  g/mL and 0. 68  g/mL lower in INH-MTB with Dop, Mpa over-expression strains than that in INH-MTB, respectively. The differences had no statistical significance (P > 0. 05). Conclusions: These results show that PPS effects the drug resistance of the INH-MTB strain.

Background: Lung cancer is the mostcommoncancer and the leading cause of cancer deaths. Streptococcus pneumoniae is the most common pathogen found among lung cancer patients that has shown increased resistance towards various antibiotics. Reports on bacterial colonization especially S. pneumoniae colonization in patients with lung cancer are scarce. Objectives: The study aimed to determine the prevalence and antibiotic resistance of S. pneumoniae isolated from lung cancer patients with pneumonia infection not undergoing any surgical procedure. Methods: Bronchoalveolar lavage (BAL) and blood samples for blood culture and PCR were collected from 152 lung cancer patients with pneumonia. Blood culture and BAL specimens were cultured to isolate S. pneumoniae and antibiotic resistance was determined by minimum inhibitory concentration assay. Results: Of the 152 blood samples, 85 (55. 9%) samples from blood culture method and 97 (63. 8%) samples from BAL specimens were positive for bacterial growth. Streptococcus pneumoniae was the predominant organism isolated from both blood culture (45. 9%) and BAL (46. 4%) specimens. Forty-seven (30. 9%) samples were found to be positive for S. pneumoniae by PCR. The detection of S. pneumoniae in 60 patients by at least one of the 3 detection methods indicates that these patients harbored S. pneumoniae infection. Fifteen (9. 9%) patients died due to the severity of pneumonia, rapid progression of lung cancer, multiple therapeutic failures, and unknown etiology. All our isolates were susceptible to penicillin; however, 48. 7% and 60% of the isolates respectively from blood culture and BAL specimens were found to be resistant to erythromycin. Conclusions: Streptococcus pneumoniae was the predominant organism colonized in lung cancer patients diagnosed to have pneumonia and showed higher resistance towards erythromycin. Our results emphasize the need for a continuous monitoring of S. pneumoniae colonization and resistance patterns, which needs to be considered during treatment of lung cancer patients with pneumonia.

Background: Black walnut (Juglans nigra) is known to have antimicrobial and antifungal effects in vitro. Objectives: This study aimed to compare the effects of extracts derived from green-husked walnut with clotrimazole against Candida albicans in female rats. Methods: In this study, 35 female Wistar rats were randomly assigned to 5 groups. A total of 4 groups of rats were infected vaginally with C. albicans and 1 group was not infected (negative control). The 4 infected groups received the following treatments: 2 groups received vaginal creams containing 2% or 4% of J. nigra extracts, respectively, 1 group received 1% clotrimazole, and 1 group did not receive any treatment (positive control). All rats received treatments for 2 weeks. Results: The mean number of colony forming unit (CFUs) before intervention was 308. 2  8. 73 and 219  13. 4 in the 2% and 4% J. nigra group, 312. 7  28. 32 in the clotrimazole group, 233. 85  8. 15 in the positive control, and 0 in the negative control group (P < 0. 001). After 1 week, the number of CFUs significantly decreased to 71. 1 3. 9 in the 2% J. nigra, 0 in both 4% J. nigra and clotrimazole groups, 230. 7 9. 86 in the positive control, and 0 in the negative control group (P < 0. 001). After 2 weeks, no CFUs were detected in any of the infected groups except for the positive control group. Conclusions: Vaginal creams containing 4% J. nigra significantly eliminated C. albicans in female rats after 1 week and its effect was similar to that of clotrimazole.

Background: Heparin-binding hemagglutinin (HBHA) protein is a surface adhesin that mediates the attachment of Mycobacterium tuberculosis to host cells by its own unique, carboxyl-terminal region. The methylated HBHA has a specific motif with a lysine-, alanine-, and proline-rich domain. More recently, it has been shown that HBHA protein has potential activity in stimulating immune responses, and is a promising new candidate for diagnostic applications besides a protective antigen against tuberculosis. Objectives: The aim of this study was to isolate a mycobacterial latency gene (hbha), and subsequently produce its protein as a new antigen for the Interferon-Gamma Release Assay test (IGRAs). Methods: In the present work, hbha and mtb32C genes were isolated from the Mycobacterium tuberculosis H37Rv genome using the polymerase chain reaction (PCR) method. The PCR products and pet21+ vector were digested with specific restriction enzymes and then submitted to the ligation procedure. Escherichia coli BL21-CodonPlus (DE3) competent cells were transformed with the recombinant mtb32C-hbha-pet21+ vector. Expression of recombinant protein (Mtb32C-HBHA) was confirmed with Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) and western blot methods. Results: Detection of a 500-bp gene and sequencing of recombinant pet-mtb32C-hbha vector, all confirmed the accuracy of the cloning procedure. A 36-KDa band of Mtb32C-HBHA protein was also detected by western blotting. Conclusions: In this study, expression of Mtb32C-HBHA protein was successfully done, in the prokaryotic system. Further studies are needed to evaluate the efficacy of recombinant Mtb32C-HBHA protein in diagnosis of latent tuberculosis.

Background: Mycoplasma pneumoniae is one of the most common causes of atypical pneumonia, which is almost asymptomatic and self-limited. Objectives: The current study aimed at investigating the prevalence of M. pneumoniae among children with pneumonia in Ahvaz, Iran, using bacterial culture growth, polymerase chain reaction (PCR), and serology tests. Methods: A total of 136 throat swab and serum specimens were collected from patients with pneumonia. The specimens were cultured on pleuropneumonia-like organisms (PPLO) agar. Molecular identification of the throat swab specimens was performed using the amplification of P1 gene. Determination of M. pneumoniae-specific antibodies (IgG and IgM) in the sera was carried out by the enzyme-linked immunosorbent assay (ELISA) technique. Results: In the current study, the acute infection was detected in 16 cases. Moreover, 3 out of 136 cases had positive results in their bacterial culture. Mycoplasma pneumoniaeDNAwas detected in 11 of the 136 cases. An acceptable titer of IgM was observed in 12 cases. On the other hand, 4-fold or greater titer of IgG was detected in 14 cases. Conclusions: The results of the current study suggested that the combination of PCR and the serology results were effective to detect M. pneumoniae. Moreover, the combination of PCR and IgM results can detect all cases of acute infection with M. pneumoniae in children.

Background: Hepatitis C virus (HCV) causes one of the major chronic liver diseases (CLD). Hepatitis C virus-core encoding sequence possesses an overlapping open reading frame (ORF) that expresses a protein called F or core+1. Objectives: The current study aimed at assessing the presence and titer of anti-core+1 antibody (Ab) in 70 Iranian patients infected with HCV-1a, responder and non-responder groups, under combination therapy with pegylated interferon- (PegIFN- ) plus ribavirin (RBV) using an enzyme-linked immunosorbent assay (ELISA). Methods: In the current cohort study, HCV-1a core+1 gene was amplified and cloned into vector followed by expressing in Escherichia coli and then, purified by ion exchange chromatography. The antibody titer of patients was evaluated before, during (12, 24, and 48 weeks), and 6 months after the end of therapy (ETR). Results: The seroprevalence of anti-core+1 Ab was 75. 7% in pretreatment sera. The combination therapy could induce a decline in the level of anti-core+1 Ab in both groups of responders and non-responders. These changes were significant only in the responders (P = 0. 003). The seroprevalence of anti-core+1 Ab had no correlation with the outcome of treatment. Conclusions: According to the current study results, HCV core+1 protein elicit a specific antibody response other than the anti-core protein antibodies. The current study data also suggested that the level of anti-core+1 antibodymightbeaffected by the combination therapyandassociated with sustained virological response (SVR). The data implied that the declining trend of anti-core+1 Abs during the treatment might be an alternative representation of the therapeutic response in Iranian population infected with HCV.

Background: Invasive aspergillosis (IA), a serious and fatal disease, is caused by numerous opportunistic fungi including Aspergillus species. Lack of early diagnosis and delay in treatment lead to the rapid spread of the infection and relapse, increase treatment costs, and ultimately cause death. Objectives: This study aimed at investigating the presence of Aspergillus species by Galactomannan EIA (GM) and TaqMan q PCR methods. Methods: Fluid samples of bronchoalveolar lavage (BAL) were collected from 89 patients, who were at risk for IA and underwent a bronchoscopy at Shariati hospital in Tehran, Iran. The specimens were examined using direct examination, culture methods, and GM and TaqMan real-time PCR. Results: A total of 23 samples were found to be positive in direct examination, 7 were identified as Aspergillus fumigatus, and 11 were positive as A. flavus in culture assays, 27 were GM positive, and 29 were positive with PAN Aspergillus probe. Moreover, 7 samples were positive with A. fumigatus probe and 11 were positive with A. flavus probe. Negative predictive value (NPV), sensitivity, positive predictive value (PPV), and specificity for a  1. 0 BAL GM level were 98. 4%, 94. 4%, 62. 9%, and 85. 9%, respectively, and were 100% for TaqMan Real time PCR. Conclusions: Our findings revealed that TaqManreal-time PCR has a great value for detection of Aspergillus species in BAL specimen. Since early diagnosis has been highly considered to prevent the occurrence of drug resistance and mortality rate, it is necessary to use this method directly to detect Aspergillus species in BAL or blood specimens without culture. Onthe other hand, Galactomannan assay with a 98. 4% NPVcould be usedto screen the patients with suspected invasive aspergillosis. Additionally, dueto the lack of need for specialized devices, an appropriate diagnostic technique should be used in laboratories that do not have access to specializGalactomannan,Real Time PCR,Clinical Samples,Bronchoalveolar Lavage,Aspergillus Detectioned procedures.

Background: Dengue is one of the main health problems worldwide with dramatic increases in reported cases in the last few decades. Now, dengue is a major threat to half of the world’ s population and approximately 50 million infections occur every year. Objectives: The major aim of this study was to screen out different synthetic antiviral compounds against dengue virus. As treatments used for dengue virus infections are nonspecific and effectless, it is necessary to find specific antiviral compounds that may be helpful in the treatment of dengue fever. In cell culture models, thiazolides are active against anaerobic bacteria, protozoa, and a range of viruses. Methods: Samples from positive dengue fever patients were included in the study. For dengue serotype-2, serum samples were further confirmed by serotyping protocol. Results: After toxicological analysis, a sharp significant antiviral response was shown by compounds A and B decreasing the viral titer of serotype 2 as 46% and 53%, respectively. A greater antiviral activity was indicated by compound “ B” against NS3 gene as compared to compound “ A” . Against NS3 gene, a comparable antiviral activity was observed for compounds “ A” and “ B” . Conclusions: From our results, it can be concluded that compounds A and B (Thiazolides) as dengue antiviral drugs can reduce viral load in patients if their inhibitory effects are reproduced in vivo. To identify the specific active ingredients, further studies are required by using various techniques to determine the efficacy of these compounds in animal model.

Background: Urinary tract infections are the most commonly encountered infections in clinics and outpatient settings and are mainly caused by Uropathogenic Escherichia coli (UPEC). Multidrug-resistant bacteria (MDR) have become a major public health threat, worldwide. Objectives: This study aimed to investigate the prevalence of theMDRphenotype, efflux pump-mediated resistance, and the ability for in vitro biofilm formation among UPEC clinical isolates from Egypt. Methods: Uropathogenic E. coli isolates were collected from two Egyptian governorates, identified, and classified to their corresponding phylogenetic group by the polymerase chain reaction (PCR). Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. AcrAB-TolC efflux pump major genes were detected by PCR; efflux pump-mediated resistance was determined by the efflux pump inhibitor microplate-based assay. The ability for in-vitro biofilm formation was also tested. Results: The phylogenetic analysis of the UPEC isolates revealed that most of the isolates belonged to groups B2 and D. The MDR phenotype was detected in 90. 8% of UPEC isolates; efflux pump-mediated resistance was detected in all MDR isolates. The acrA, acrB, and tolC were detected in 74. 84% of MDRisolates. The ability for in-vitro biofilm formation was recorded in 76. 5% of theUPECisolates. Conclusions: The MDR phenotype and the ability for in-vitro biofilm formation were predominant among UPEC in Egypt. The high prevalence of MDR efflux pumps necessitates the application of new treatment strategies to inhibit this phenomenon.