The Iranian Journal of Microbiology (IJM) is the offi­cial scientific quarterly publication of the Iranian Society of Microbiology which is published by Tehran University of Medical Sciences.  The areas that are covered by IJM are medical, veterinary, food and water, applied and  environmental microbiology. It ac­cepts Original Papers, Review Articles, Short Communications and Let­ters to the Editor in the fields of Microbiology.


Current Issue

Vol 15 No 1 (2023)

Review Article(s)

  • XML | PDF | downloads: 93 | views: 150 | pages: 1-9

    The gut microbiome plays an important role in the health of the body. The study of its effect on mental problems has become the main topic of this study. As a matter of fact, every change in the gut microbiota composition can influence on mood and anxiety and vice versa. So, considering this “microbiota-gut-brain” axis (GBA) is so important. In this narrative review, the most recent reproduced information on GBA roles in neuropsychiatric disorders, and clinical significance have been considered. The gut microbial population is formed from birth and transforms from an immature state to the postnatal period into a more intricate and diverse adult ecosystem. In this review, we had some findings that GBA implicated in some psychiatric problems which can be a dysregulation consequence. In addition, some bacteria have been implicated in causing mental disorders in humans such as depression, obsessive-compulsive disorder, psychiatric disorders, stress disorders, schizophrenia and, autism. The absence of balance in GBA natural state can cause several negative consequences on host health which leads to neurological problems. Possibly, findings were delineating an interesting new etiological pathway for future exploration.

  • XML | PDF | downloads: 56 | views: 85 | pages: 10-18

    Background and Objectives: One of the most prevalent drug-resistant bacteria is methicillin-resistant Staphylococcus epidermidis (MRSE) causing healthcare infections. Previously, a meta-analysis study on the frequency of MRSE was conducted from Mar 2006 to Jan 2016 in Iran. The present study aimed to evaluate the changes in this prevalence in the last 5 years in different cities in Iran.
    Materials and Methods: Published articles on the frequency of MRSE were collected from the Web of Science, PubMed, Scopus, Google Scholar, Cochrane Library, and Iranian databases from the beginning of 2016 to the end of 2020. Of the 503 records identified, 17 studies met the inclusion criteria, and their extracted data were analyzed using comprehensive meta-analysis version 2.0 (Biostat).
    Results: The analysis showed that the frequency of MRSE has decreased significantly in the last five years and reached 60.8 [95% confidence interval (95% CI) 54.2-66.9] among culture-positive cases of S. epidermidis in Iran.
    Conclusion: The noticeable reduction in the prevalence of MRSE in Iran could be due to the improvement of infection control programs and interruption of the pathogen transmission cycle. Another influential reason is the significant reduction in methicillin prescriptions by physicians for infections caused by staphylococci.

Original Article(s)

  • XML | PDF | downloads: 60 | views: 99 | pages: 19-26

    Background and Objectives: Ventilator-associated pneumonia (VAP) is the second most common nosocomial infection in pediatric intensive care units. The aim of this study was to evaluate the contribution of multiplex PCR in the diagnosis of VAP and its impact on the clinical and prognostic outcome of children in the ICU.
    Materials and Methods: This is a prospective observational study from March to November 2021, including bronchial samples collected from 38 intubated children hospitalized in ICU. The detection of respiratory pathogens was performed by the FilmArray® Pneumonia Panel plus (FAPP).
    Results: Multiplex PCR (mPCR) detected exclusively 46 potentially pathogenic bacteria, giving a sensitivity of 93%, specificity of 90%, negative predictive value of 100%, and positive predictive value of 23%. Overall, the sensitivity of mPCR was higher for Gram-negative bacteria (100%) than Gram-positive (92%). Bacterial etiology was the most frequent (69.3%), represented mainly by Moraxella catarrhalis (11.4%), followed by viral etiology (30.7%), with Rhinovirus/Enterovirus as the most prevalent virus. FAPP enabled a change in antibiotic therapy in 39.5% of the patients, with a 73.3% survival rate.
    Conclusion: This study highlights the importance of mPCR in diagnosing VAP and improving antimicrobial therapy.

  • XML | PDF | downloads: 53 | views: 102 | pages: 27-37

    Background and Objectives: Klebsiella pneumoniae causes challenging nosocomial fatal infections including neonatal sepsis. Our study aims at clarifying the contribution of integrons in the observed reduced susceptibility of multidrug-resistant (MDR) K. pneumoniae isolated from septicemic neonates to the clinically used antimicrobial agents and biocides.
    Materials and Methods: Eighty-six K. pneumoniae isolates were collected from Mansoura University Children’s Hospital from septicemic neonates. Isolates were subjected to antibiotic and biocide susceptibility using disk diffusion and the agar dilution method, respectively. The distribution of different classes of integrons was screened in the isolates by PCR. Detected inegron I was sequenced in selected isolates.
    Results: Fifty-seven isolates (66.27%) were MDR. In the MDR isolates, class I integron was detected in 23 (40.3%), integron III was detected in 20 (35%), whereas integron II could not be detected. Sequencing results of integron I from MDR K. pneumoniae isolates revealed that only aminoglycoside and folate synthesis inhibitors gene cassettes were detected, while the rest of the resistance genes were not associated with integron I.
    Conclusion: The presence of integron I in MDR K. pneumoniae tested isolates may contribute only to some biocide resistance, however, it does not seem to be the only contributor in multiple drug resistance.

  • XML | PDF | downloads: 54 | views: 94 | pages: 38-44

    Background and Objectives: Burkholderia cepacia is one of the multiple intrinsic resistant bacteria causing opportunistic infections. The study aimed to determine the distribution of B. cepacia isolates based on types of clinical specimen, hospital wards, and the patient's gender-age and to evaluate their antibiotic susceptibility.
    Materials and Methods: This study involved isolating, identifying, and testing antibiotic susceptibility of B. cepacia isolates recovered from clinical specimens of Dr. Zainoel Abidin general hospital (RSUDZA) Banda Aceh Indonesia during March 2019-March 2022.
    Results: In total, there were 3,622 Gram-negative bacterial isolates of 10,192 clinical specimens obtained during the study period and B. cepacia was positively detected in 127 isolates (1.24%). Most of the 127 isolates of B. cepacia were found in blood and sterile body fluid samples (55.11%) followed by urine and pus samples accounting for 23.62% and 13.37%, respectively. The internal medicine wards had the highest number of detected B. cepacia isolates at 28.3%. B. cepacia infections were more common in men (59.05%) and people over 45 years old (41.73%). The bacteria were highly sensitive to the antibiotic ceftazidime (92.7%).
    Conclusion: Culture examination of clinical specimens is not required for confirmed infections, despite being essential for appropriate antibiotic treatment. Implementing surveillance programs and judicious use of antibiotics can prevent bacterial transmission.

  • XML | PDF | downloads: 58 | views: 101 | pages: 45-54

    Background and Objectives: The steady increase in the spread of multidrug-resistant Pseudomonas aeruginosa (MDR) has become a major threat to the global health systems, including Iraq. This study aimed to investigate the prevalence and the molecular basis of antibiotic resistance in Pseudomonas aeruginosa isolated from clinical and environmental samples.
    Materials and Methods: Pseudomonas aeruginosa strains were identified by standard microbiological procedures followed by PCR confirmation. Antibiotic susceptibility testing, for 16 antimicrobials, was conducted according to the Clinical and Laboratory Standard Institute (CLSI) standardized by disk diffusion and VITEK 2 methods. Detection of beta-lactamases (ESBLs, AmpC and carbapenemase) activities and related encoding genes was performed by using phenotypic methods and PCR technique respectively.
    Results: A total of 81 clinical specimens and 14 environmental samples were positive for P. aeruginosa. Antimicrobial susceptibility test showed high rates of resistance to antipseudomonal cephalosporines (74.74 to 98.95%), aztreonam (82.11%), antipseudomonal carbapenems (68.4%), piperacillin/tazobactam (69.5%) ciprofloxacin (71.6%), and aminoglycosides (69%), with emergence of resistance to colistin (7.4%) among tested P. aeruginosa. Among the tested isolates, 69 (72.63%) strains were MDR, of which 63 (91.3%) strains were extremely drug resistance (XDR). Most of the isolated strains harbored one or more of ESBL genes (blaSHV-2a, blaCTX-M-28, blaVEB-2, blaOXA-677, blaPER) with predominant blaOXA-677, but none of the MBLs (GIM, SIM, SPM, IMP) and AmpC (FOX) genes were detected.
    Conclusion: The results highlighted a high prevalence rate of MDR and XDR and emergence of colistin resistance P. aeruginosa at Basra hospitals, Iraq.

  • XML | PDF | downloads: 53 | views: 109 | pages: 55-61

    Background and Objectives: The misuse of antibiotics in recent years has led to an increase in antibiotic associated diarrheas (AAD). Out of several implicated pathogens, Clostridioides difficile is responsible for causing 15-25% of all cases of AAD. However, it has remained under diagnosed for a long time. The current study is planned to explore prevalence of C. difficile amongst AAD patients and to study clinical presentation and associated risk factors.
    Materials and Methods: Hospital based cross sectional study conducted in patients above 2 years of age. Diagnosis of C. difficile was done by two modalities i.e. glutamate dehydrogenase test followed by toxin detection using enzyme immunoassay and stool culture followed by toxin gene detection.
    Results: Twelve of 65 patients (18.4%) were positive for C. difficile. Maximum cases were found in younger age group. Abdominal pain and fever were most common complaints. 12 (18.4%) out of 65 study subjects were found to be positive by ELISA. 2/65 (3%) patients were positive for culture with presence of only tcdB gene. Ceftriaxone was the most commonly used antibiotic (25%).
    Conclusion: C. difficile is significant pathogen implicated in AAD with a prevalence rate of 18.4%. GDH antigen detection followed by Toxin A/B ELISA for C. difficile yielded better detection rate as compared to stool culture.

  • XML | PDF | downloads: 44 | views: 81 | pages: 62-68

    Background and Objectives: Klebsiella pneumoniae is a clinically relevant opportunistic pathogen belonging to the Enterobacteriaceae family. It is in the top three bacteria associated with antimicrobial resistance deaths globally, and one of the most dangerous bacteria causing nosocomial infections. Phage therapy offers a potential option for the treatment of drug-resistant bacterial infections.
    Materials and Methods: Phage PSKP16 was isolated against K. pneumoniae, capsular type K2 (isolated from a wound infection). PSKP16 is a new lytic phage with a Siphovirus-like morphology.
    Results: PSKP16 is a linear double stranded DNA phage with a GC content of 50% and genome size of 46,712 bp, for which we predicted 67 ORFs. PSKP16 belongs to the genus Webervirus and shows high evolutionary proximity to Klebsiella phages JY917, Sushi, and B1.
    Conclusion: Phage isolation is fast, cheap and efficient, but it requires time and characterization (which adds expense) to ensure that the isolated phages do not pose a health risk, which is essential to safely use phage therapy to treat life-threatening bacterial infections.

  • XML | PDF | downloads: 34 | views: 72 | pages: 69-78

    Background and Objectives: Recent evidences have shown that methicillin-resistant Staphylococcus aureus (MRSA) can cause severe infections and is resistant to almost all commercially available antibiotics. Therefore, screening unknown sources of biological compounds such as the Thermoactinomycetaceae family as extremophilic bacteria may be helpful to find new antimicrobial agents.
    Materials and Methods: Various samples were collected from different ecosystems, including desert, volcano, compost, and forest. They were cultured on Soil extract agar and Water agar. The antimicrobial activity of the isolates was evaluated using agar overlay and well diffusion methods. Members of the Thermoactinomycetaceae family were selected for further study: Their ability to grow at different temperatures, NaCl concentrations, and pH values, enzyme production ability, antimicrobial secondary screening, fractionation of their supernatants and so on.
    Results: According to molecular identification of active isolates against MRSA, three strains, including Laceyella sacchari UTMC 2705, Thermoactinomyces sp. UTMC 2721, and Laceyella sp. UTMC 2731, belonged to Thermoactinomycetaceae were identified. The minimum inhibitory concentrations of their extracts were tested against some pathogenic bacteria, showing their antimicrobial activity with a broad spectrum. The results of TLC bioautography of the extracts showed that the most active fractions were semi-polar. Also, the results of HPLC analysis showed the existence of several UV-active compounds in their extracts.
    Conclusion: The present study highlighted the importance and potential of Thermoactinomycetaceae members as a less-known source of antibiotics against pathogenic bacteria.

  • XML | PDF | downloads: 60 | views: 111 | pages: 79-88

    Background and Objectives: Carotenoid pigments are among the most important pigments and have many applications in various food, cosmetics, hygiene industries and biotechnology. These pigments are produced by plants and microorganisms including Rhodotorula spp. This research intended to study the antimicrobial and antibiofilm effects of the carotenoid pigment from Rhodotorula glutinis on food spoilage bacteria (Staphylococcus aureus and Salmonella Typhimurium).
    Materials and Methods: The R. glutinis was isolated from milk samples of cows with mastitis and ITS sequence-based typing was performed on them. After extracting the pigment from R. glutinis, its purity was examined using thin-layer chromatography. Following that, the broth microdilution method was used to evaluate antimicrobial effects of the pigment and MtP assay and subsequently scanning electron microscopy were used to assess the antibiofilm effects. In addition, the sub-MIC effects of the pigment on expression of quorum-sensing (QS) genes in S. Typhimurium isolates (sdiA and luxS) and S. aureus isolates (hld) were studied. Finally, the degree of toxicity of the pigment was analyzed using the MTT assay.
    Results: ITS sequence analysis of R. glutinis revealed that the recently separated isolates exhibited strong differences with the strains recorded in NCBI database in genetic structure. The pigment produced by R. glutinis had strong antimicrobial effects and its mean MIC against S. Typhimurium isolates (17.0 μ was higher than the mean MIC against the S. aureus isolates (4.1 μ Electron microscope images and real-time observations indicated that the sub-MIC values of the pigment suppressed biofilm formation by suppressing expression of QS genes. In addition, the mentioned pigment at high MIC concentrations did not have toxic effects on Vero cells.
    Conclusion: This research suggests that R. glutinis pigment is effective in destroying the planktonic form of food spoilage bacteria and degrading food spoilage biofilm-forming bacteria. Moreover, considering the low toxicity level of R. glutinis pigment for eukaryotic cells, we can suggest its use as a natural antibacterial preservative in various food materials.

  • XML | PDF | downloads: 43 | views: 93 | pages: 89-101

    Background and Objectives: Honey is one of the oldest traditional remedies that has been widely utilized to cure a variety of human ailments. The objective of this research was to test and compare the antibacterial activity of Sidr honey (SH) and Tualang honey (TH) to that of Manuka honey (MH) against Staphylococcus aureus.
    Materials and Methods: The antibacterial activity of MH, SH and TH against S. aureus was investigated by agar well diffusion, Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), time-kill curve, microtiter plate and RT-qPCR analysis.
    Results: Agar inhibition assay showed that MH possess highest total antibacterial activity against S. aureus with an inhibition zone 25.1 mm compared with that of SH (22.2 mm) and TH (21.3 mm). The findings showed that when compared to SH and TH (MIC: 25% and MBC: 50%), MH honey had the lowest MIC (12.5%) and MBC (25%). After S. aureus was exposed to MH, SH, and TH, there was a decrease in colony-forming unit as seen by the time-kill curve. The lowest concentration 20% of MH, SH and TH was significantly found to inhibit S. aureus biofilm. The RT-qPCR results revealed that all the selected genes in S. aureus were downregulated in gene expression following exposure to each of the tested honeys. Comparing the total antibacterial, antibiofilm, and antivirulence activities of all the tested honeys, MH demonstrated the greatest levels of these properties.
    Conclusion: According to this study, various types of each evaluated honey have the capacity to effectively suppress and modify the virulence of S. aureus via a variety of molecular targets.

  • XML | PDF | downloads: 44 | views: 92 | pages: 102-110

    Background and Objectives: Peptic ulcer disease is a multifactorial disease that affects up to 10% of people. The use of natural product remedies has received much attention for its treatment. In this research, the healing effect of metabiotic extracted from Bifidobacterium bifidum was investigated.
    Materials and Methods: 45 male wistar rats were divided into 3 groups (Ctrl-, drug, and metabiotic), and stomach ulcers were induced by ethanol administration and treated by drug and metabiotic. The healing process was investigated on different days by histological analysis and qRT-PCR.
    Results: The metabiotic increased IL-8 and PDGF expression and stimulated the recruitment of polymorphonuclear cells to the wound site. It caused a faster onset of the inflammation phase followed by the proliferation phase. The metabiotic increased the expression of SOD and GPx genes and the antioxidant capacity of the wound. The increase in EGF expression led to faster re-epithelization, which was evident in the wound closure process.
    Conclusion: Metabiotic extracted from B. bifidum is a promising candidate for the treatment of PUD. It causes a faster onset of the inflammation phase. Improving the antioxidant status of the wound, causes a faster resolution of inflammation, which leads to the acceleration of the wound-healing process.

  • XML | PDF | downloads: 36 | views: 68 | pages: 111-120

    Background and Objectives: Spirulina platensis micro-algae have some effects on cellular procedures. The proliferative potential of mesenchymal stem cells (MSCs) will be decreased after repetitive passage.
    Materials and Methods: The stromal cells were isolated, and then proven by differentiating to adipogenesis and osteoblastic lineage. The cell markers such as CD90 and CD105 were detected by flowcytometry. MSCs were treated with extract of S. platensis in logarithmic concentrations. MTT and ATP assays were done to determine cell proliferation capacity. The antioxidant and antimicrobial properties of the extract were evaluated.
    Results: The results obtained from differentiation confirm cells’ potential for osteoblastic and adipoblastic differentiation. Detection of CD90 and CD105 markers over 70% proved that the majority of cells are MSCs. Statistical analyzes revealed a significant increase in MSCs proliferation in the concentration of 0.9 µl/ml S. platensis. DPPH assay demonstrated that the extract could scavenge free radicals up to 57%. Additionally, the extract showed the inhibition zone up to 11 mm against a different strain of bacteria by agar well diffusion assay.
    Conclusion: Secreting nutritional elements, S. platensis extract can be used as an antioxidant, antimicrobial, and growth agent for enhancing the proliferation of MSCs. Furthermore, the optimum concentration for cell treatment with S. platensis’s extract was investigated.

  • XML | PDF | downloads: 45 | views: 86 | pages: 121-127

    Background and Objectives: The causative agent of Middle East Respiratory Syndrome (MERS) is a zoonotic Coronavirus (MERS-CoV) identified in Saudi Arabia in 2012. The envelope (E) protein of MERS-CoV is a small viral protein which plays several essential roles during virus replication. To facilitate study of the structure and function of the E protein, recombinant MERS-CoV E protein was expressed using the baculovirus expression system.
    Materials and Methods: A recombinant E open reading frame including an 8-histidine tag at the amino terminus was designed and cloned into a baculovirus transfer vector. Following construction of a recombinant virus insect cells were infected and the expression of the E protein assessed by SDS-PAGE and Western blotting.
    Results: Recombinant E protein, tagged at the N-terminus with a polyhistidine sequence, with a molecular mass of 10.18 kD was identified by Western blotting with an anti-His antibody. Following large scale infection E protein was released by detergent mediated lysis of infected cells and purified by Immobilized Metal Ion Affinity Chromatography (IMAC).
    Conclusion: Purified full length recombinant MERS-CoV E protein can be isolated by IMAC and is suitable for further functional, biophysical or immunological studies.

  • XML | PDF | downloads: 30 | views: 64 | pages: 128-137

    Background and Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) glycoprotein that projects from the virus surface is highly immunogenic. It is considered to be the target of many neutralizing antibodies as well as a target in vaccine design efforts. Evaluation the immunogenicity of a recombinant fragment of the spike protein (rfsp) that is comprised of Receptor Binding Domain (RBD), S1/S2 cleavage site, and fusion peptide (FP) as immunogenic proteins of SARS-COV-2, in BALB/c mice and evaluation of the efficacy of epitopes rfsp as a multi-subunit chimeric vaccine.
    Materials and Methods: The present study made use of CHO-K1 (Chinese hamster ovary K1) cells to create a cell line for constant expression rfsp. The rfsp was purified with Ni-NTA chromatography and confirmed by Western blotting. The immunogenicity and neutralizing antibody efficacy of rfsp were evaluated in BALB/c mice. ELISA was employed to test rfsp via sera of COVID-19 convalescent patients infected with SARS-CoV-2 alpha and delta variants.
    Results: Our results showed significant differences in antibody titers in immunized mice compared to the control groups and neutralizing antibodies were positive, sera from mice immunized are capable of bound SARS-CoV-2 virus, chimer peptide is capable bound antibodies patients infected with SARS-CoV-2 and patients infected with delta variant SARS-CoV-2.
    Conclusion: Overall, these results indicate that rfsp protein would be a novel potential antigen candidate for the development of a subunit SARS CoV-2 vaccine and rfsp has the potential to be a useful option for the development of the assays for serodiagnosis of SARS-CoV-2 infection.

  • XML | PDF | downloads: 40 | views: 97 | pages: 138-148

    Background and Objectives: The interaction between nanoparticles (NPs) and viruses is attracting interest because of the antiviral potential of NPs. This study aims to investigate the antiviral potential of NPs against Herpes simplex virus types 1 (HSV-1).
    Materials and Methods: Molecular docking studies were conducted by Molegro virtual docker software. An extract of Juglans regia green husk was utilized to biosynthesize copper-oxide nanoparticles (CuNPs). The cytotoxicity of NPs was evaluated by MTT assay. Different treatment assays were conducted. Another assay was designed to employ the concentration of 300 μg/ml of CuNPs, which is the highest concentration that did not precipitate. Finally, chemically synthesized Iron oxide nanoparticles (FeNPs) were utilized to adsorb CuNPs. The antiviral effect of FeNPs was investigated, separately.
    Results: Docking results confirmed that NPs could interact with the HSV-1 glycoproteins and prevent viral entry. MTT assay results illustrated that the minimum non-toxic concentration (MNTD) of CuNPs is 100 μg/ml which did not exhibit antiviral properties. Employing a noncytotoxic concentration of FeNPs (300 mg/ml) in combination with cytotoxic concentration of CuNPs (300 μg /ml), eliminated the cytotoxicity effects of CuNPs. Exposure of the virus with the combination of CuNPs and FeNPs resulted in 4.5 log10 TCID50 reductions in HSV-1. While treating HSV-1 with only FeNPs reduced the titer of virus by 3.25 log10 TCID50.
    Conclusion: The results highlight that combination of CuNPs and FeNPs have antiviral activity against HSV-1. Moreover, FeNPs demonstrated antiviral properties against HSV-1 separately.

  • XML | PDF | downloads: 31 | views: 67 | pages: 149-154

    Background and Objectives: Various infectious and non-infectious factors can cause encephalitis in the central nervous system (CNS), the most important of which are viruses. Herpes viruses are one of the most important causes of encephalitis worldwide. PCR detected the virus on the cerebrospinal fluid (CSF) sample. The aim of this study was to set up an in-house PCR to identify herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) and determine the prevalence of these viruses in suspected children of encephalitis.
    Materials and Methods: This cross-sectional study was conducted on 160 suspected children with encephalitis cases referred to Dr. Kermanshahi Children Hospital, Kermanshah, Iran, from April to March 2021. CSF samples were extracted using a viral extraction kit, and a PCR was performed. The level of glucose and total protein of the samples was measured.
    Results: The total prevalence of HSV was 16.25%. 17 samples were positive for HSV-1 (10.6%), and 9 samples for HSV-2 (5.6%). There was a significant correlation between glucose, total protein, and HSV PCR positive, but no significant correlation between age and HSV PCR positive results.
    Conclusion: Rapid diagnosis of a virus may reduce the hospitalization rate and the use of unnecessary therapies and crease mortality, morbidity, and disability in children. Results in this study show that the distribution of HSV types in children with encephalitis predominantly was type 1 compared with type 2.

  • XML | PDF | downloads: 35 | views: 68 | pages: 155-162

    Background and Objectives: Human rhinoviruses (HRVs) and human adenoviruses (HAdVs) are among the most prevalent viruses in hospitalized patients with severe acute respiratory infection (SARI). This study aimed to evaluate the molecular characterization of HRV and HAdV in hospitalized patients with SARI, who aged ≤ 18 years in Tehran, Iran.
    Materials and Methods: To detect these two viruses, a conventional nested RT-PCR (Reverse transcription-polymerase chain reaction) assay was performed on 264 throat swabs collected from December 2018 to March 2019. The epidemiological data were analyzed and phylogenetic trees were constructed.
    Results: Of 264 cases with SARI, 36 (13.6%) and 28 (10.6%) were positive for HAdV and HRV respectively. Of 21 HRV sequenced samples, HRV-A (42.9%), HRV-B (9.5%) and HRV-C (47.6%) and of 36 HAdV sequenced samples, HAdV-C6 (38.9%), HAdV-B7 (22.2%), HAdV-B3 (11.1%), HAdV-B16 (5.6%), HAdV-C5 (13.9%), HAdV-C57 (5.6%), HAdV-E4 (2.8%); were detected in children with SARI. Some viral genotypes appeared to cause more severe disease, which may lead to hospitalization.
    Conclusion: Large-scale studies are recommended to investigate the epidemiology and molecular characterizations through surveillance networks to provide useful information on etiology, seasonality, and demographic associations in patients with SARI.

  • XML | PDF | downloads: 59 | views: 92 | pages: 163-173

    Background and Objectives: Candida tropicalis is one of the major non-albicans species causing nosocomial infection. There is limited data about mechanisms of azole-resistance and virulence factors of Candida tropicalis. This study was designed to investigate molecular mechanism of azole -resistance and major virulence factors of C. tropicalis isolated from oropharyngeal candidiasis in head and neck cancer patients.
    Materials and Methods: After collecting 38 C. tropicalis clinical isolates, antifungal susceptibility pattern and the expression levels of ERG11, CDR1, CDR2 and MDR1 were evaluated. Moreover, proteinase and phospholipase activity and biofilm formation of the isolates were investigated as virulence factors.
    Results: We detected fluconazole resistance in 7 C. tropicalis isolates. The expression levels of CDR1, ERG11 and MDR1 were increased respectively. Protease activity and biofilm formation were seen in all isolates. Five isolates did not exhibit phospholipase activity.
    Conclusion: Taken together, the overexpressions of ERG11, CDR1 and MDR1 genes were found in fluconazole resistant C. tropicalis, isolated from oropharyngeal candidiasis patients. Also, voriconazole was an effective antifungal against C. tropicalis isolates. The observed high protease enzyme activity and biofilm formation suggested strong pathogenicity of these isolates.

  • XML | PDF | downloads: 37 | views: 60 | pages: 174-180

    Background and Objectives: Fungi communities are important soil components as decomposers and plant symbionts, and they play an important part in natural ecological and biogeochemical processes. In this study, isolation and identification of terrestrial and zoosporic fungi were detected.
    Materials and Methods: Sixty–seven fungal species from thirty–four genera were isolated from 45 soil samples obtained randomly from nurseries in Al–Qurayyat, Jouf reagon, Saudi Arabia using the soil dilution technique on glucose–Czapek’s agar medium, cellulose–Czapek’s agar, and Potato dextrose agar medium.Authentic fungus manuals were then used to identify and characterise the mycoflora.
    Results: A total of 46 fungal species belonging to 22 terrestrial fungal genera were recovered on glucose–Czapek’s agar, 38 species belonging to 20 terrestrial fungal genera were recovered on cellulos–Czapek’s agar and 27 fungal species belonging to 15 terrestrial fungal genera were recovered on PDA medium while 12 species belonging to 7 genera zoosporic fungal genera were discovered.
    Conclusion: The most common terrestrial fungal genera were Aspergillus, Penicillium, Fusarium, Trichoderma, Acremonium, and Cladosopium while in zoosporic fungus. Allomyces was the most prevalent, followed by Achlya and Pythium.

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