IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY
Year:2017 | Volume:11 | Issue:1|Papers Count:14

The Middle East respiratory syndrome coronavirus (MERS-CoV) as a causative agent of severe lower respiratory tract infection in humans, considered as a global threat, especially against to Persian Gulf countries. Since its discovery in 2012, MERS-CoV has spread 27 countries affecting about 1800 people and caused more than 600 deaths in worldwide. In comparison to SARS (severe acute respiratory syndrome), MERS-CoV appears to have a higher mortality rate (40% versus 10%) and is particularly more severe in patients with underlying medical conditions. Until now, the most MERS-CoV cases (more than 85 percent) have had a history of travel or residence in the Middle East countries. A possible intermediate host for MERS-CoVis camel. Clinical manifestations of MERS range from mild or asymptomatic disease to acute respiratory syndrome and multi-organ failure resulting in death, mostly in individuals with preexisting medical co-morbidities. There is no specific antiviral treatment for MERS and infection prevention and control practices are necessary to prevent spread of MERS-CoV in health care facilities. In present study, we have briefly outlined the recent information about the epidemiology, clinical features, diagnosis, treatment and prevention of MERS-CoV.

Background and Aim: Pseudomonas aeruginosa is a gram-negative pathogen that causes a variety of serious infections predominantly in immunocompromised patients. To promote severe illness, P. aeruginosa uses a type III secretion system to inject toxic effector proteins into the cytoplasm of eukaryotic cells. Four effector proteins have been described in P. aeruginosa: ExoU, ExoS, ExoT, and ExoY. The aim of the study was to determine the prevalence of the type III secretion system toxins-encoding genes among P. aeruginosa isolates collected from different clinical specimens such as urine, wound, blood and respiratory secretions from patients.Materials and Methods: 55 Pseudomonas aeruginosa isolates were identified from hospitalized patients in Tehran during 2015– 2016, using conventional microbiological tests. The susceptibility of isolates to antibiotics were assessed using disk diffusion test. After DNA extraction, Multiplex PCR was performed on the P. aeruginosa isolates to detect the secretion toxins-encoding genes.Results: High resistance rates were seen for cefipime (89%), ceftazidime (85.45%), aztreonam (83.63%), tobramycin (78.18%) and gentamicin (60%). The prevalence of the genes among all isolates was as follows; exoT (76.32%), exoS (30.90%), exoY (14.54%) and exoU (67.27%). exoU was more prevalent among MDR than in non-MDR strains (81.3% versus16.6%). exoU+ isolates were more likely to be fluoroquinolone-resistant than exoS+ isolates (32% versus 17%).Conclusions: Type III secretion system toxins-encoding genes found in isolated P.aeruginosa, in which exoT, exoU and exoS gene detected in most isolates while exoY gene was detected in minaroty of the isolates.

Background and Aim: Salmonella enteritidis is one of the most common causes of gastroenteritis, and in acute cases may lead to septicemia and even death. In this study, genetic markers of serovar were screened by comparative genomic methods, and the most specific marker was targeted to identify this pathetic serover by LAMP method.Materials and Methods: This study was done in 2016. To find genetic markers of S. enteritidis, 50 complete genomes of S. enteritidis and other genera belonging to Enterobacteriaceafamily were compared by different comparative genomic methods. The specific marker was selected and targeted by the LAMP method using six special primers to demonstrate the feasibility of comparative genomic methods for screening specific genetic markers (The bacterial strains used in this study were collected from hospitals in the Southast of Iran). The efficiency of LAMP assay for the identification of this bacterium was also evaluated in artificially contaminated chicken meat samples.Results: lygC gene was selected as the most specific marker for detecting S. enteritidis strains. LAMP assay results showed that the selected gene is specific for detectingS. enteritidis isolates. The assay sensitivity was determined to be 10 CFU/reaction for pure bacterial culture, 103 CFU/mL for contaminated chicken meat samples without pre-enrichment, and 10 CFU/mL after a 4-h pre-enrichment.Conclusions: The present study demonstrates that comparative genomic methods are efficient tools for the identification of specific genetic markers. Also, the present LAMP method could be used as a powerful, accurate and inexpensive tool for detectingS. enteritidis in food quality and clinical laboratories.

Background and Aim: Acinetobacter baumannii is one of the most important multi drugresistant species associated with nosocomial infections. Several factors involve in resistance to drug and its pathogenicity. Of these factors, OmpA protein plays a crucial role. Therefore, the aim of current research was to assess resistance to drug and alsoomp A gene existence in A. baumanniiisolated from clinical sources.Materials and Methods: Firstly, clinical samples were collected from Imam Khomeini, Milad and Motahari Hospitals during 2015-2016 years and the final confirmation were done by using biochemical methods. Afterwards, susceptibilities to antibiotics of different classes were determined by disc diffusion method and presence ofompA gene was checked by using PCR method and verified by sequencing.Results: The results show that of 650 clinical samples, 156 (24%) of isolates were formed ofA. baumannii and mostly showed resistance to different classes of antibiotics.92.95% of isolates were multi drug resistance (MDR) and finally 86.53% were extremely drug resistance (XDR). All of them containedomp A gene.Conclusions: Existence of multi drug resistance in most isolates as well as presence of ompAin all samples can cause bacterial virulence and drug resistance. It seems essential to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii, decrease the moral and material damage caused by the bacteria.

Background and Aim: Brucellosis is still an important zoonotic infection and evaluation of immunologic properties of various bacterial antigens along with different vaccination strategies helps in designing efficient vaccines against the disease. The aim of this study is to immunological evaluate the eukaryotic vector pVAX1, carrying the outer membrane protein gene of 31 kDa (Omp31) B.melitensis.Materials and Methods: In this study which was carried out in 2014, whole sequence of omp31of B. melitensis was inserted between BamHI and XhoI of pVAX1 plasmid vector. Female BALB/c mice aged 6-8 weeks (purchased from Pasteur Institute of Iran) were immunized intra-muscularly with 100μg of the construct, followed by either protein or plasmid boosters separately. The level of IL-4, IL-12, IFN-g, total serum IgG, and specific IgG1 and IgG2a against recombinant Omp31 were evaluated. Finally the protective immune response following exposure to B. melitensis 16M was evaluated.Results: DNA-vaccine omp31 career with protein reminders Omp31, stimulate higher levels of IFN-g, IL-12 and IgG2a compared to groups of DNA-vaccine or recombinant protein. Protective immunity was also significantly higher in mice which immunized with DNA vaccine–protein regimen.Conclusions: Mice which immunized with DNA vaccine–protein regimen showed a significantly higher levels of IL-12 and IFN-g along with serum IgG2a which together imply augmentation of T cell-mediated immune responses against Omp31. The latter was confirmed by significant protective response to B. melitensis 16M challenge.

Background and Aim: Amikacin, as an aminoglycoside antibiotic, is prescribed against a broad spectrum of bacteria. Limiting the use of this medicine includes the risk of microbial resistance, toxicity and short half-life in the body. One strategy to overcome the problem is the use of nanotechnology which can help to development of medicine delivery systems. This study was done in 2015 to assess the ability of mesoporous silica nanoparticles in improving the traditional formulation of amikacin.Materials and Methods: SBA-15 was synthesized using hydrothermal method. The kinetics of medicine release from carriers, was investigated at 37 °C. The antimicrobial activity of formulations was conducted by disk diffusion method and broth dilution test on samples of bacteria.Results: Nanoparticles SBA-15 with a hexagonal arrangement and pore diameter of 5 -100 nm, were able to encapsulation 47% of Amikacin. The kinetics of medicine release from the carrier at pH (5, 7.4and 8.9) showed that in the first 24 hours, respectively, 10, 34.54 and 69% amikacin was released from the carriers. The rate of MIC of native amikacin and amikacin @SBA-15 of S. aureus were respectively, 1.66, 13.29 mg / mL and for P. aeruginosa were respectively 3.32, 26.59 mg/ mL.Conclusions: The results confirmed the stability of the encapsulated amikacin and high capacity SBA-15 to control the medicine release in the acidic environment of the stomach to the intestinal alkaline that made hopes to provide oral formulation of the medicine.

Background and Aim: Breast cancer is the most common malignancy among women and Epstein Barrvirus could be a reason to develop this cancer. The aim of this study is to evaluate the association betweenEpstein Barr virus and breast cancer by Immunohistochemical method in Fars province hospitals.Materials and Methods: This study was carried out in 1390-1395.80 cases of breast cancer tissue samples were selected from formalin-fixed paraffin embedded blocks from Fars province hospitals and by immunohistochemistry method the expression of the LMP1 viral protein were examined. Data analyzed by SPSS statistical software.Results: Epstein Barr virus was not detected in the breast cancer tissues and expression of viral protein of LMP1 was not observed in any of the breast cancer specimens by Immunohistochemistry.Conclusions: The results were shown that Epstein Barr virus may not be associated with breast cancer in Fars province and further studies are needed to determine the relationship between breast cancer virus with a variety of molecular methods.

Background and Aim: Leishmaniasis is a disease which caused by Leishmania protozoan parasitic. Plant extracts and their derived compounds, provide a rich source of medicinal compounds which is by the World Health Organization considered as a candidate drug for the treatment of many diseases. This study aimed to evaluate anti-Leishmania effects of Persian Gulf brown algae extract compared to meglumine control drug in vitro.Materials and Methods: Leishmania major promastigotes were cultured in RPMI-1640 medium containing 10% FBS and antibiotics, at temperature 1 ± 24 and the effect of different concentrations of Persian Gulf brown algae was evaluated by MTT assay in comparison with meglumine onLeishmania major promastigotes. The optical density was read by ELISA reader at wavelength of 540-630 nm. The results are expressed as IC50 (Inhibitory Concentration %50).Results: The IC50 amount of extract obtained as 20 mg/ mL for Leishmania major after 72 hours of incubation. So that the IC50 amount of meglumine control drug is 21.8mg/mL for Leishmania major.Conclusions: The effectiveness of these extracts on these parasites is roughly equivalent meglumine and have the potential of using as an anti-Leishmania drug but there is need to do more tests to assess effects of this extract onLeishmania agents in animal models and In vivo.

Background and Aim: The ice cream is consumed in abundance due to its high nutritional value and flavor, According to neutral pH and abundant nutrients, ice cream is a suitable environment for microbial growth. Some ice cream ingredients such as milk and egg can be contaminated with pathogenic microorganisms such assalmonella. Therefore ice cream consumption can cause food poisoning. The aim of this study was to determine thesalmonella contamination of traditional ice creams in Zabol city.Materials and Methods: In this descriptive-analytical study in 2015 years, 90 traditional ice cream samples were collected from different shops of Zabol city and then in sterile conditions were transferred to food laboratory food and microbiological tests were performed on samples.Results and Conclusion: In this study, 62 samples (68.8%) of 90 collected ice cream samples, were found positive for Salmonella. Salmonella contamination is prevalent in ice creams in Zabol. Main causes of contamination are using of unpasteurized milk, lack of attention to hygienic issues and lack of proper washing of dishes.So more accurate monitoring of ice cream shops in Zabol are required.

Background and Aim: Brucellosis is one of the most common zoonotic disease between human and cattle breeding. Brucellosis is endemic in all regions of Iran. Since brucella is an arbitrary intracellular organism and a limited range of antibiotics are effective to it, this study is based on the survey of the antibiotic sensitivity to the 9 isolated B.melitensis from raw milk in tribes population.Materials and Methods: Antimicrobial susceptibility of 9 B.melitensis bacteria isolated from nomadic livestock population’s raw milk were studied in the laboratory. The minimum inhibitory concentration (MIC) of tested antimicrobial substances were measured by E- test. To interpret the results, CLSI standards were used for bacteria growth.Results and Conclusions: 9 isolates had a high sensitivity to Doxycycline, two isolates were resistant against three antibiotics Streptomycin (MIC³240mg/mL) Cotrimoxazole (MIC³256mg/mL) and Rifampin (MIC³30mg/mL) and six other isolates were showed Intermediate and sensitivity to former antibiotics. According to results, resistance to Rifampin and Streptomycin and Cotrimoxazole were the important result of this article.

Background and Aim: Ganoderma lucidum is a main source of ganoderic acid. This metabolite has pharmaceutical effects such as cancer treatment. However, due to low yields and high prices, clinical application is difficult. Stimulants such as elicitor and mechanical shocks can be used to increase the produce of ganoderic acid effectively. This study aimed to investigate the effect of ultrasound on the production of this medicine.Materials and Methods: In this study, a liquid culture of the fungus treated with the once and twice at 20 and 200 seconds of sound with a frequency of 50 kHz and constant output power in ultrasonic bath was investigated. After extraction of ganoderic acid and ensure of positive impact of shock, to optimize variables, response surface methodology was used. In this method, 17 experiments with three variables, the first time ultrasound (4, 5, 6 days), the second ultrasound (7, 8, 9 days) and time of ultrasound (60, 180, 300 seconds) by Design Expert software were designed and done.Results: The results showed that the effects of ultrasound stimulation with twice 274 seconds treatment on days 4 and 7 were established highest ganoderic acid production. By comparing samples with control (without sound) Increase in extracellular ganoderic acid to intracellular ratio was determined. In optimum conditions, 34% increase in GA production relative to the control sample was observed.Conclusions: Ultrasound can be used as a non-chemical and cheap stimulus, increase ganoderic acid production.