IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY
Year:2016 | Volume:9 | Issue:4|Papers Count:14

Background and Aim: Several studies were investigated legionella contamination in natural and man- made water resources. The aim of this research was systematically review of legionella water contamination in natural and man-made resources.Materials and Methods: In this systematic review study, the required data wascollected using suitable keywords through PubMed, Science direct, Springer link, Google scholar, SID, Iranmedex, Irandoc and Magiran databases. The search was conducted without publication date limitation. Survey and selection of articles was conducted based on PRISMA checklist and Cochrane quality assessment standards. Out of 1386 articles, 56 articles were considered after excluding the remaining articles which were not related to the study objectives. Identification and isolation of legionella with PCR technique and culture in BCYE is one of the article selection criteria. The relevant data were classified in extracted table and analyzed manually. Excel 2007 software was used for to draw diagrams.Results: Out of 56 articles, 9 and 47 articles were published in Iran and foreign countries respectively. In Iran, 5.7-70 % of samples were contaminated. In Iran’s hospitals 2.85-41.75% of samples were contaminated by Legionella pneumophila. In foreign countries, 0-100% of samples were contaminated and in these countries’ hospitals Legionella pneumophila contamination was 17%-98.7%.Conclusions: Although in Iran legionella water contamination is lower than foreign countries but, based on WHO guideline (1CFU/L) for legionella, planning for control of this bacteria and relevance infectious is one of the health priorities.

Background and Aim: Infections caused by Staphylococcus species associated with biofilm are considered as a serious clinical concern in medical devices used patients with serious clinical illness and are usually possible source of nosocomial infections. The polysaccharide adhesion mechanism encoded by the ica operon generate a direct role in biofilm formation and infection of the bacteria. In this study, the presence of ica operon were studied in clinical isolates of S. aureus and S. epidermidis in relation to the biofilm formation.Materials and Methods: In this study, the 27 S. aureus isolates and 73 S. epidermidis isolates were identified by conventional biochemical methods. The ability to biofilm formation was evaluated by colony morphology on Congo red agar (CRA) and test tube. Presence of the ica genes was detected by PCR method.Results: In this study, from 27 S. aureus isolates and 73 S. epidermidis, 25 (93%) and 70 (96%) isolates had the ability to form biofilms respectively. Genetic analysis showed that icaRADBC operon was present in 4 and 11% of S. aureus isolates and S. epidermidis isolates respectively. The S. epidermidis isolates were more frequently positive for icaA, icaB and icaC than S. aureus while the most prevalent gene was icaD found in 30% of the S. aureus isolates.Conclusions: The results obtained showed that in consistent with other researches; biofilm formation in Staphylococcal isolates was not associated with present of ica operon and presumably depend on several factors.

Background and Aim: Mycoplasma is the smallest self-replicating bacteria polymorphic are having a diameter of about 200-500 nm, and lees cell wall. Because of their small size and flexibility to easily pass through the filter membrane and contaminate represented. These organisms are unique in nature, the wide range of diseases among animals, especially respiratory & genitalia diseases were among the rodents. The aim this study was to isolate and identify the molecule M. pulmonis of Rats.Materials and Methods: With aim to isolation of M. pulmoni, the tracheal samples were collected and cultured on the medium 243 and Microaerophilic was placed. Genomic DNA was isolated from bacteria grown. 16SrRNA gene amplified with PCR. The PCR products, finally to identify the bacteria was purified, sequenced were a BLAST.Results: Macroscopic studies on the isolated colonies showed fried egg colonies were established. Based on the 16SrRNA sequencing studies, this bacterium belonging Mycoplasma genus & had 99% similarity to M. pulmoni.Conclusions: Due to the lack of similarity of 100%, a new strain of bacterium, M. pulmoni strain IRMT179 name were called. Finally, the gene bank was recorded with acceptation number KP836312. This study is the first time in Iran; M. pulmoni was isolated from the respiratory tract an urban rat.

Background and Aim: The rising trend of antibiotic resistance among A. baumannii strains has become a global concern. The most common mechanism of resistance is beta-lactamase production with genes transferring on mobile genetic elements such as plasmids. The aim of this study was to determine the frequency of blaNDM, blaGIM, blaAIM, blaDIM and blaVIM type genes among A. baumannii isolates from hospitalized patients in Tehran, Iran.Materials and Methods: From May 2012 to July 2013, 108 A. baumannii strains were isolated from blood, wound, urine, sputum and respiratory tract of hospitalized patients in Loghman hakim and Milad hospitals. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and broth microdilution methods according the CLSI guidelines. The frequency of MBL (Metallo-Beta-Lactamase) producers was evaluated by CDDT. The β-lactamases genes were detected by PCR method.Results: The resistance of A. baumannii isolates against tested antibiotics were as follows: 103 (95.4%) to ceftazidime, 108 (100%) to cefotaxime, 105 (95.7%) to cefepime, 99 (91.7%) to imipenem, 99 (91.7%) to meropenem, 87 (80.6%) to amikacin, 105 (97.2%) to piperacillin, 100 (92.6%) to ciprofloxacin, 103 (95.4%) to piperacillin/ tazobactam, 44 (40.7%) to gentamicin, 106 (98.1%) to ampicillin/sulbactam, 106 (98.1%) to co-trimoxazole, 87 (80.6%) to tetracycline, and 1 (0.9%) to colistin. Using combined disk diffusion test, 86 (86.86%) were MBL producers. The prevalence of blaVIM-1 gene was 15 (17.44%) and other genes were not detected.Conclusions: The prevalence of MBLs-producing A. baumannii strains detected in this study is a major concern and highlights the need for infection control measures such as antibiotic management protocols and rapid identification of resistant strains.

Background and Aim: Pseudomonas aeruginosa is an opportunist pathogen. The infections due to biofilm are difficult to eradicate with current antimicrobial agents. In this study, we investigated the antimicrobial and antibiofilm activity of the honey against 40 P. aeruginosa isolates.Materials and Methods: To assess antimicrobial activity, the MIC and MBC assays were used. Antibiofilm activity of tested honey evaluated using the MTP, Congo Red Agar, and tube methods.Results: The initial screening demonstrated that 40 of 80 P. aeruginosa isolates were biofilm- producer. The honey exhibited a significant antibacterial activity against the planctoninc form of P. aeruginsa. The MIC of Polak, Baboneh and Yonjeh honeys against P. aeruginsa were, 12.5-25, 6.25-25 and 12.5-25% w/v, respectively .The results indicated that the tested honey also had significant antibiofilm activity.Conclusions: Antibacterial effects of honey are observed in both planctonic and biofilm forms .However, higher concentrations of honey have needed to inhibit biofilm. These findings indicate the potential antimicrobial of Azerbaijan honey and, it can be used in the treatment of bacterial infections diseases due to P. aeruginosa.

Background and Aim: Probiotic are live microbial food supplement which bestows beneficial effects on the host by creating intestinal microbial balance. In this research, we aimed to identify locally isolated Lactic Acid Bacteria (LAB) with probiotic potentials by phenotypic and genotypic methods.Materials and Methods: A number of locally isolated LAB identified by phenotypic characteristics were selected and screened for their probiotic properties. The isolates were tested for their acid and bile resistance, antibacterial activity, cholesterol reducing. The selected probiotic LAB were identified to species level by using universal primers and 16S rRNA sequencing.Results: Among the 20 LAB isolates, only 3 isolates resisted low pH value of 2.5, while 5 isolates resisted 0.3 to 1% bile salt. Among these 5 isolates, 3 isolates showed the ability to lower cholesterol significantly as they reduced 94.8, 95.73 and 97.82 % of cholesterol within 2 hours of incubation. Based on 16S rRNA sequencing these 5 isolates were identified as Lactobacillus plantarum (22SN, 24SN, NPN0022, 10SN), and Lactobacillus rhamnosus (30SN).Conclusions: The LAB isolates in this study possessed significant probiotic properties and might be used as a probiotic in human, livestock, and poultry products in the future.

Background and Aim: Pathogenic Pseudomonas aeruginosa strains produce polar pili has required for motility, adhesion, and invasion. The main aims of the present study are to identify, clone, express and purify the recombinant pilin protein of P. aeruginosa in the prokaryotic host.Materials and Methods: The recombinant pilin gene (pilA) was isolated from P. aeruginosa PAO1 strain by PCR and cloned into pET-22b vector. The recombinant plasmid was subsequently verified by restriction analysis, and DNA sequencing. The recombinant vector was transformed into E. coli BL21 (DE3) strain, then the recombinant pilin overexpressed and affinity purified by Ni-NTA agarose-affinity chromatography. Western blot analysis was performed using anti-6His tag antibody.Results: The PCR and enzymatic digestion results showed the accuracy of the pilA gene cloning. The protein electrophoresis showed that the molecular weight of recombinant pilin is about 19 kDa. Western blot analysis also confirmed the production of recombinant protein. The amount of produced protein was measured by the direct spectrophotometery method, which was 2.58 mg/mL.Conclusions: Western blot and ELISA results along with that of sequencing ensure accurate production of recombinant pilin, retaining its partial epitopes.

Background and Aim: Environmental pollution by petroleum compounds have turned into one of the global concerns. The aim of the present research was evaluation of the indigenous fungal strains of Iran to remove crude oil pollutants.Materials and Methods: First, the contaminated soil samples were collected. The samples were enriched in minimal salts medium (MSM) medium with 1% crude oil and chloramphenicol for 3 weeks and the isolates were purified. The crude oil degradation was measured by total petroleum hydrocarbon (TPH) assay method at 420 nm. In order to confirm the amount of oil degradation by selected isolate, the residual hydrocarbon content was evaluated by FTIR. Laccase activity in the presence of 1% crude oil was measured. Finally, the selected isolate was identified using morphological and molecular methods.Results: In this study 30 fungal strains were isolated. The isolate G-05 was selected as a premium isolate by TPH test. This strain showed that 66% degradation of petroleum hydrocarbons after 15 days. Residual crude oil analysis with FTIR spectrophotometry showed that G-05 is able to degrade 90% of aliphatic compounds. Evaluation of laccase activity showed that this isolate can produced 1440 U/l of enzyme after 15 days. Presence of laccase activity in G-05 was showed that using of non-specific ligninolytic enzymes are the main mechanisms of oil hydrocarbons degradation in mentioned strain. The strain was identified as a member of Phaeosphaeria genus by molecular and morphological tests.Conclusions: Fungi have high potential in bioremediation of contaminants such as crude oil pollutants; however, few studies have been carried out in this field. For the first time, the results of this study showed that Phaeosphaeria has a high potential in bioremediation of the oil contaminated soils.

Background and Aim: In hepatitis B Virus, one of major problem associate lamivudine therapy is the emergence of YMDD motif mutation in Polymerase gene leading to lamivudine resistance mutations. The aim of this study was evaluation of the incidence of the YMDD mutants among patients with chronic hepatitis B and Renal transplant recipients (RTRs).Materials and Methods: In this study, 80 chronic hepatitis B patients who received renal transplants at Tehran city were selected. The patients serum samples were collected for molecular evaluation by nested PCR assays were used for the direct identification of hepatitis B Virus surface antigen (HBsAg). After laboratory tests the results were analyzed by using molecular software.Results: In this study, of the 80 patients, 30 patients were positive for HBV DNA. They were between 28 to 74 years old with the mean of 51±23.The frequency of lamivudine resistance mutations in YMDD region was detected in 12 (40%) of chronic hepatitis B patients.Conclusions: Much is still unknown about Lamivudine therapy among chronic hepatitis B RTR patients, but most studies have confirmed Lamivudine therapy in these patients is safe and it is better to use it before renal transplantation. It is suggested to follow up patients in terms of immunosuppressive therapy and HBV molecular analysis in different status of disease. Therefore, it will be possible to investigate the effect of these mutations in chronic hepatitis B RTR patients who receive immunosuppressive drugs.

Background and Aim: Nearly 350 million people worldwide are carriers of the Hepatitis B virus (HBV). A medical worker is one of the most important occupational groups at risk for the virus. Despite vaccination, in many of them, antibody reduced and if the exposure to infected materials, there is a possibility of infection to HBV. This study, examines some of hepatitis B serologic markers among students in Babol University of Medical Sciences.Materials and Methods: 236 students in Babol University of Medical Sciences were enrolled to our study. For all students participating in the study, a questionnaire including demographic information, history of the first and last dose vaccination for Hepatitis B, blood transfusion and blood products and surgical history were completed. 5 ml of venous blood was taken from each student and serum was separated and stored in -20oC. For all samples, ELISA test operated for Anti-HBs and Anti-HBc and HBsAg.Results: Of the 236 students, 155 (65.7%) were female and 81 (34.3%) were males; of which 194 cases (82.2%) completed the vaccination period, 22 (9.3%) incomplete vaccination or not vaccinated and others students (8.5%) were unaware of their vaccination status. The presence of Anti-HBs, 202 cases (85.6%) were positive and 34 (14.4%) were negative and Anti-HBc were positive in 4 students (1.7%). Also, all samples were negative by the presence of HBsAg.Conclusions: About 15% of students are susceptible to HBV; therefore, screening for antibody to be recommended, before enter to university. Serological studies in preclinical years are necessary to ensure adequate protection before the students are in close contacts to patients.

Background and Aim: Marine actinomycetes, gram positive bacteria, have been prolific sources of novel secondary metabolites with a range of biological antibacterial activities. Marine sediments are potential sources for isolation of novel actinomycetes yielding new products and are recognized as source of novel antibiotic. In this study, we reported the isolation, characterization and antifungal activities of 8 actinomycetes isolated from Deylam nearshore sediments.Materials and Methods: The marine soil sediment samples were collected from Deylam nearshore at the depth of 10 cm. The treated samples were serially diluted and used starch casein agar as a culture medium. Morphological and biochemical characterization of isolated strain was carried out by using standard methods. Antifungal assay of the bacterial extracts was performed using standard well diffusion assay.Results: In this study, 8 marine actinomycetes were isolated from Deylam near shore sediments according to their morphology. All of isolate was belonged to Streptomyces genus. Differential analyses results for catalase and Gram test were positive for all isolates, the positive isolates for TSI, simmon citrate and ornitin decarboxylase were 1, 2 and 5 respectively, all isolates were negative for lysine decarboxylase, VP, MR and indol test, SIM test results showed that all isolates were non-motile, one isolate was produced H2S and some isolates formed pigmented colony. Most isolates showed antifungal activity against tested pathogenic fungi.Conclusions: Results of this investigation revealed that the marine actinomycetes of Deylam nearshore sediments were potent source of bioactive compounds with antifungal activity.

Background and Aim: Campylobacter spp. are pathogenic for human and animals. They are transmitted from animals and animal products to human and cause diarrhea and systemic disease. Campylobacter jejuni is the main species and the most common human pathogen. The aim of this study is the isolation of Campylobacter jejuni from the poultry feces and determination of their drug resistance pattern.Materials and Methods: In this survey, within 2 years, 600 poultry feces samples randomly were collected from Islamkish in kerman. Collected samples were from secome section of poultry. The feces containment were inoculated into campylobacter selective medium containing antibiotics and sheep blood agar and then were incubated in microaerophilic condition in 42oC. The resulted colonies were confirmed to the species level using diagnostic tests. Drug resistance pattern against three antibiotics including tetracycline, ampicillin and co-trimoxazole was determined by disk diffusion method.Results and Conclusion: In this survey, 190 (31.66%) C. jejuni were isolated. Drug resistance pattern showed that the prevalence of resistance to tetracycline, ampicillin and co trimoxazole were 54%, 54, and 91%, respectively. Regarding to the results, C. jejuni isolated in this study in Kerman had been more resistant to cotrimoxazole.

Background and Aim: One of the most important childhood infections is urinary tract infection (UTI). In order to prevent serious complications of UTI in children such as hypertension and renal failure, definitively diagnose and prompt treatment are essential. Since bacteria of the family Enterobacteriaceae are known to be the most common causes of UTI, the present study aimed to determine the frequency and antimicrobial resistance patterns of them in children with UTI.Materials and Methods: The present study was conducted on urine samples of children with UTI referred to Children’s Medical Center of Tehran during one year. The urine samples were cultured on selective media and the bacteria were identified by biochemical tests. Antibiotic resistance pattern of isolates were investigated by disk diffusion method.Results and Conclusion: Out of 1348 positive urines for Enterobacteriaceae bacteria, more cases of UTI were observed in outpatient (1050, 77.89%) than in hospitalized patients (298, 22.11%). Escherichia coli was the most common bacteria isolated among family Enterobacteriaceae, with prevalence of 76%. The clinical isolates had the most sensitivity to Amikacin and Piperacillin-Tazobactam, respectively (93%), and (98%) and resistance to Cephalothin (80%). Considering the prevalence of urinary tract infections, especially in children under 2 years and also in girls, the knowledge of local resistance pattern and well-timed eligible treatment are imperative. Accordingly, Amikacin and Piperacillin-Tazobactam are recommended for empirical treatment in children with UTI.