Iranian Journal of Medical Microbiology
Year:2017 | Volume:11 | Issue:4|Papers Count:12

Background and Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs), are used as analgesic and antipyretic agents. In this study NSAIDs were used to overcome the resistance of Pseudomonas aeruginosabio films to Tobramycin antibiotics. The aim of this study was to find an easy and low-cost method, using NSAIDs and Tobramycin, to deal with the biofilms of P.aeruginosa.Materials and Methods: Follwoing molecular remodeling, NSAIDs were used alongside Tobramycin against PAO1 strain ofP. aeroginusa. The Plate Reader measured the absorbance of crystal violet solution in ethanol. The Infiltration rate of NSAIDs in biofilms and its absorbance were measured by Tetrazolium salt and Plate Reader, respectively.Results: After performing the docking techniques, the most suitable conformation of NSAIDs, to inhibit LasR and PqsE proteins, were chosen. Having worked on dual inhibitors, we could find a configuration in which the inhibition coefficient was at its lowest level for both PqsE and LasR. The findings showed a lower rate of biofilm formation by bacteria treated with NSAIDS and Tombramycin.Conclusions: Based on the constructional similarities in some NSAIDs, like Piroxicam, Meloxicam and Homoserine lactones (AHLS), these drugs can be used as quorum-sensing system inhibitors to inhibit LasR and PqsE protein and hence reduce the P. aeruginosa pathogenesis.

Background and Aims: Brucellosis or Malta fever is one of the most prevalent zoonotic diseases considered as a health and economic problem in many countries in the Middle East, including Iran. The consumption of contaminated milk, milk products and contact with infected animals are the main transmission ways of pathogenic Brucella strains among human. The aim of the current study was to determine simultaneous detection ofBrucella abortus and Brucella melitensisin raw and none-pasteurized bulk cow milk tanks of traditional domestic dairy sale centres in Khorramabad, Iran.Materials and Methods: In this cross-sectional study during October and November 2015, a total of 120 samples from raw and unpasteurized bulk cow milk tanks were collected from traditional domestic dairy sale centres in Khorramabad. To confirm the presence of Brucellagenus among the samples, single PCR was carried out using B4 and B5 primers and multiplex PCR was then carried out in order to detect theB. abortus and B. melitensis spp.Results: The present study revealed that 10% of the bulk milk tank samples in traditional domestic dairy sale centres in Khorramabad were contaminated withBrucella.Conclusions: Results of PCR assay showed that raw and unpasteurized bulk cow milk tanks of traditional domestic dairy sale centres in Khorramabad are the potential cause of human brucellosis in this region.

Background and Aims: Salmonella enterica serovar Typhimurium is one of the common causes of food poisoning in human. Since the selection of appropriate markers is one of the main challenges for the detection of this pathogen, in the current study, genetic markers of this serovar were screened using bioinformatical tools. In the second phase, structure and function of proteins encoded by these markers, were determined.Materials and Methods: This study was conducted between 2016 and 2017. In order to find the genetic markers ofSalmonella enterica serovar Typhimurium, 45 complete genomes belonging toSalmonella enterica serovar Typhimurium and the other genera of Enterobacteriaceafamily were compared using Mauve software. To determine the structure and function of proteins encoded by these sequences, I-TASSER and Phyre2 software beside CDD, Inter Pro Scan, DALI, and Pro Func databases were used for structural and functional modeling, respectively.Results: Special regions of STM4491 - STM4496 genes were determined as specific markers forSalmonella enterica serovar Typhimurium. The function of proteins encoded by these markers were proposed to be classified in five groups, including Lon protease, nucleotide binding proteins, nucleotide three phosphatases (NTP), proteins involved in the DNA repair, and DNA methylase.Conclusions: Specific regions of STM4491 - STM4496 genes can be used as effective diagnostic targets for the detection of pathogenicSalmonella enterica serovar Typhimurium.Moreover, proteins encoded by these genes can be suggested as suitable targets for the design of new therapeutic agents to prevent and treat the infections caused by this pathogen.

Background and Aims: Vitamin D3 deficiency can causes many diseases such as rickets, osteopenia and osteoporosis and increases the risk of some types of cancer. Probiotic strain of Lactobacillus plantarum, which can store fat-soluble vitamin D3 in its bulk, can reduce the effects of vitamin D3 deficiency in addition to being able to produce products with probiotic benefits.Materials and Methods: This research was carried out in 2016. By designing the onefactor-at-a- time tests, the range of possible effective variables on vitamin D3 absorption in bacterial mass and effective factors were selected. Optimization of vitamin D3 entrapment in biomass of bacteria was performed using response surface methodology via Box-Behnken design. The high-performance liquid chromatography was employed for determination of vitamin D3 quantities.Results: Among the parameters affecting vitamin D3 entrapment, three factors including incubation temperature, initial vitamin D3 and sucrose concentrations were most effective. The optimal points were obtained at vitamin D3 concentration of 351723.537 IU/mL, sucrose concentration of 2.89 (g/L) and incubation temperature of 33.8 oC. The maximum value of vitamin D3 in dry cell weight ofL. plantarum was 1028.5 IU/g which was consistent with the proposed statistical model.Conclusions: In this study L. plantarum enriched with vitamin D3 was produced and optimized for the first time. Experimental and statistical studies confirm the accuracy and reliability of this optimization.

Background and Aims: Marine sponges have specific ability to growth in complex conditions deal with microorganisms by production of secondary metabolites. These metabolites can be used to degrade and inhibit the formation of microbial biofilms. Eliminating biofilms is important from the industrial and health aspect.Materials and Methods: In this study the antimicrobial effects of methanol: dichloromethane (1: 1) extracts of three marine sponges inDysidea sp genus collected in 2015 at Persian Gulf, were studied against 6 human pathogenic bacteria. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of each extracts was determined. In biofilm level, the destruction of biofilm and inhibition of biofilm production by each extract was carried out separately.Results: The results of this study showed that the Dysidea spc have the highest inhibitory effect on planktonic form of studied bacteria. The maximum inhibitory effect on biofilm formation related to extracts of Dysidea sp.a in 12.5 mg/mL concentration against B. cereus and the minimum inhibitory effect in this concentration against P. aeroginosa. The highest destructive biofilm effect of Dysidea sp.c extract was observed in 6.25 mg/mL against K.pneumonia and lowest destruction in 12.5 mg/mL concentration was recorded against B. cereus.Conclusions: The results obtained in this research confirmed that each marine sponges have different inhibitory effect against tested bacteria. This difference can be related to production of bioactive compounds and symbiosis microorganisms with these sponges.

Background and Aims: Klebsiella pneumoniae is one of the most common causes of nosocomial infections. The aim of this study was to determine the frequency of theblaTEM and blaSHVgenes in K. pneumoniae strains isolated from blood samples of neonates admitted to some health centers in Rasht.Materials and Methods: In this study, 163 isolates from blood samples were taken during 6 months from July to December 2015. Antibiotic susceptibility was conducted by disc diffusion method and screening test using combination disc method. Also, the presence ofblaTEM and blaSHVgenes were studied using PCR method.Results and Conclusions: Among the total of 163 cultured blood samples, 16 were positive. Only 3 strains were diagnosed asK. pneumonia (18.75%). Two out of 3 positive samples (67%) were identified as the ESBLproducers in the primary screening test. The isolated K. pneumoniahad the highest resistance to penicillin and amoxicillin (100%) and the lowest resistance to imipenem and ceftazidime (33%). The results of PCR on 3 samples showed that all the 3 isolates (100%) containedSHV gene, 1 strain (33.3%) had TEM gene and 1 case (33.3%) had bothTEM and SHV genes simultaneously. In conclusion the horizontal gene transfer among bacteria in hospitals and clinical centers and the patterns of antibiotic useage should receive more attention.

Background and Aims: Salmonellosis is an important disease among human animals and which is caused by different serovars ofSalmonella enterica. Serovars enteritidis and typhimuriumare the most prevalent serovars among human and animals which are the causes of foodborne infections. This study aimed to detect the antibiotic resistance pattern inSalmonella strains isolated from red meat as well as the molecular identification of tetracycline resistance genes.Materials and Methods: In this study, 230 red meat samples were collected during 2015 from slaughterhouses, distribution centers and industrial processing plants around Tehran and were examined using culture and biochemical tests for the presence ofSalmonella isolates.Serotyping was performed using O and H antisera. Antimicrobial susceptibility testing was done for all the strains. Detection the tetracycline resistance gene was performed using Multiplex PCR and specific primers for thetetA, tetB, tetC and tet D genes.Results and Conclusions: A total of 60 Salmonella samples were isolated and identified.The serotyping results showed that all of the 60 samples belonged to group D and serovar enteritidis. The highest resistance was against amoxicillin and the lowest resistance against gentamicin. Twenty five percent of the samples showed phenotypical resistance to tetracycline, among which 60% had thetet genes, 7 isolates (46.6%) having the tetA gene, one isolate having thetetB and one isolate possessing the tetC gene. This study showed the prevalence of Salmonellaisolates in red meat samples and and the presence of tetracycline resistance genes among these isolates.

Background and Aim: Staphylococcus aureus is an important cause of nosocomial infections. Many people are carriers for S. aureus in some parts of their body such as nose. In general, the population of carriers is higher among hospital staffs such as nurses who harbour antibiotic resistantstaphylococcus strains which can be transmitted to patients. The aim of this study was to identify and evaluate the nasal carriage of S. aureus and determination of their antibiotic resistance patterns in a statistical population of nursing students in the Islamic Azad University of Eghlid Branch during 2014-2016.Materials and Methods: The relevant data were obtained using a questionnaire and the samples were then taken by rotating a moist cotton swab inside both nasal cavities of the nursing students.S. aureus strains were isolated and confirmed using conventional tests such as gram staining, catalase, coagulase and culture on DNase and Manitol salt agar. Antimicrobial susceptibility patterns against different antibiotics such as ampicillin, erythromycin, tetracycline, and chloramphenicol were carried out using Kirby-Bauer disk diffusion.Results and Conclusions: Out of the 216 students, 68 (%31.4) were nasal carriers of S.aureus. The results revealed that the highest and lowest antibiotic resistances rates were found against penicillin (%94.1) and ciprofloxacin (%3), respectively. A large number of students are nasal carriers ofS. aureus which can increase the incidence of nosocomial infections. Therefore, it is recommended that screening and treatment for S. aureus be done for all the students and staff which are in direct contact with patients in hospitals.

Background and Aims: Epstein Barr virus is associated with nasopharyngeal carcinoma, Burkitt lymphoma and Hodgkin's lymphoma. The aim of this study was to detect the frequency ofEBV in tissue specimens from patients with Hodgkin's lymphoma in the Fars province using the immunohistochemical method.Materials and Methods: A number of 30 cases of Hodgkin’s lymphoma tissue samples were selected from formalin-fixed paraffin embedded blocks from the Fars province hospitals in 2016 and the expression of LMP1 was evaluated using the immunohisto chemical method. Data were analyzed using SPSS statistical software and Fisher’s exact test.Results and Conclusions: A total of 77% of the samples (23 of 30), were presented with Epstein-Barr virus and positive cases included 16 males and 7 females. Eighty seven percent (7 of 8) of the Hodgkin’s lymphoma patients infected with EBV were in the age group 1-14 years, 60% (3 of 5) in the age group of 15-49 years and 76% (13 of 17) in the age group over 49 years.The highest expression rate of the virus was seen among mixed cellularity Hodgkin’s lymphoma subtype (93%). According to the Fisher’s exact test, there was no significant correlation in the prevalence ofEBV subtypes among different sex and age groups (p values>0.05). The results showed a high expression of EBV among Hodgkin’s lymphoma specimens of children and adults in the Fars province. Also, the prevalence of EBV was higher among males compared to females and mixed cellularity was the predominant subtype. These results are similar to that in other developing countries.