Serogroups, and drug resistance of nontyphoidal Salmonella in symptomatic patients with community-acquired diarrhea and chicken meat samples in Tehran.

BACKGROUND: Salmonella is considered as a main cause of community-acquired diarrhea in humans, however, sources of the multi-drug resistant (MDR) strains and their link with the disease are not well known. AIMS: This study aimed to investigate the frequency, serogroup diversity, and antimicrobial susceptibility patterns of Salmonella strains in poultry meat and stool samples of patients with community acquired diarrhea in Tehran. METHODS: We compared the frequency of non-typhoidal Salmonella serogroups, the similarities of their resistance patterns to 10 antimicrobial compounds, the prevalence of extended spectrum ß-lactamase (ESBL) and ampicillinase C (AmpC) genetic determinants, and class 1 and 2 integrons in 100 chicken meat and 400 stool samples of symptomatic patients in Tehran during June 2018 to March 2019. RESULTS: Salmonella was isolated from 75% and 5.5% of the chicken meats and human stool samples, respectively. The chicken meat isolates mainly belonged to serogroup C (88%, 66/75), while the human stool isolates were mainly related to serogroup D (59.1%, 13/22). The MDR phenotype and the most common rates of resistance to antibiotics, including tetracycline, trimethoprim/sulfamethoxazole (TS) and azithromycin, were detected in 4.5% and 45.3%, 59% and 13.6%, 43% and 9.1%, 42% and 9.1% of the human stool and chicken meat samples, respectively. Carriage of bla CTX, bla SHV, and bla PER genes in the meat isolate with ESBL resistance phenotype and bla ACC, bla FOX, and bla CMY-2 among the 7 meat strains with AmpC resistance phenotype was not confirmed using polymerase chain reaction (PCR). High prevalence of class 1 and 2 integrons was characterized and showed a correlation with resistance to TS and chloramphenicol. CONCLUSION: These findings showed a lack of association between chicken meats and human isolates due to discrepancy between the characterized serogroups and resistance phenotypes.

Specific egg yolk antibodies (IgY) confer protection against Acinetobacter baumannii in a murine pneumonia model.

AIM: Acinetobacter baumannii, an increasingly serious health threat, is considered as one of the six most dangerous microbes of high mortality rate. However, treatment of its infections is difficult because of the lack of efficient antibiotic or commercial vaccines. Passive immunization through administration of specific antibodies such as IgY, could be an attractive practical solution. METHODS AND RESULTS: In the current study, antigenicity of two recombinant outer membrane proteins (OmpA and Omp34) as well as inactivated whole cell of A. baumannii was assessed by ELISA. Moreover, prophylactic effects of specific IgY antibodies (avian antibody) raised against these antigens were evaluated in a murine pneumonia model. The specific IgY antibodies had various prophylactic effects in the pneumonia model. OmpA was the most potent antigen in terms of triggering antibody and conferring protection. While a synergic effect was observed in ELISA for antibodies raised against a combination of OmpA and Omp34 (which are known as Omp33-36 and Omp34 kDa), an antagonistic effect was unexpectedly seen in challenges. The reason for this phenomenon remains to be precisely addressed. CONCLUSION: All the specific IgY antibodies could protect mice against pneumonia caused by A. baumannii. SIGNIFICANCE AND IMPACT OF THE STUDY: The specific IgY antibodies could be employed as a pharmaceutical against pneumonia caused by A. baumannii.

Heterogeneity in resistant fecal Bacteroides fragilis group collected from healthy people.

Normal nonpathogenic flora would represent a constant lake of resistance genes potentially transferable to human pathogens. To assess the prevalence of resistance genes and genetic variability of Bacteroides fragilis group (BFG) from normal flora, 177 Bacteroides isolates obtained from the fecal samples of healthy individuals. These isolates were subjected to antibiotic susceptibility testing and pulsed field gel electrophoresis (PFGE). The isolates were further tested for the presence of ermF, tetQ and bft genes by PCR. Our results indicated the presence of different clonal strains (1 common type and 57 single types) among the resistant isolates. The resistance rate for the six antibiotics in this study was between 1% and 95%. Most of the isolates (99%) were susceptible to metronidazole. ermF and tetQ were detected in all erythromycin and tetracycline resistant isolates. None of the isolates were carried bft gene. These data suggest dissemination of heterogenic clonal groups in healthy persons and resistance to 5 high commonly used antibiotics.

Trend of knowledge production of research centers in the field of medical sciences in iran.

Establishment of medical research centers at universities and health-related organizations and annually evaluation of their research activities was one of the strategic policies which followed by governmental organization in last decade in order to strengthening the connections between health research system and health system. The aim of this study is to scrutinize the role of medical research centers in medical science production in Iran. This study is a cross sectional which has been performed based on existing reports on national scientometrics and evaluation results of research performance of medical research centers between years 2001 to 2010. During last decade number of medical research centers increased from 53 in 2001 to 359 in 2010. Simultaneous scientific output of medical research centers has been increased especially articles indexed in ISI (web of science). Proper policy implementation in the field of health research system during last decades led to improving capacity building and growth knowledge production of medical science in recent years in Iran. The process embedding research into the health systems requires planning up until research products improves health outcomes and health equity in country.

The analysis of health research system evaluation in medical sciences universities.

BACKGROUND: Based on Iran by 2025 defined vision, we must to receive the first grade of science position in south western Asian region. Thus we need to have a comprehensive evaluation program. METHODS: A comprehensive WHO Health Research System Analysis (HRSA)- based evaluation system was developed to evaluate the HRS in Iran. This article has explored the results of the five-year evaluation (2003-2008) and aims to introduce this method to other developing countries. Here we explore the results of research performance evaluation from 2002 to 2010 and by comparing the results with previous available information, we reveal the probable role of this method in research promotion and proposed approach to facilitate and expedite achieving the prospects for goals of health research based on the visions of Iran by 2025. RESULTS: All of the indicators of stewardship and capacity building axes are received to their predefined levels. Moreover all of the medical science university research policies are based on their strategic plannings which are extracted from national visions of Iran by 2025. Most of the predefined goals in knowledge production domain had a significant grow trend but for more growth for commitments they should be closely follow. CONCLUSION: We developed an HRS-based comprehensive evaluation program to our national vision as well as our regional and international research competition.

The evaluation of international relationship role in promotion of health system research.

BACKGROUND: Regarding the need for scientific development and achievement our national goals, it is clear that international cooperation has the main role in this way. Here is a report on what we have done during past almost 10 years (2001-2011) in the field of international medical research activities in Deputy Ministry for Research & Technology, Ministry of Health, Iran. Our effort was focused to identify and contact with the prominent scientific centers among the world where could make a connection between our researchers in medical science universities with those centers.

Health research evaluation and its role on knowledge production.

BACKGROUND: Knowledge production and evaluation are two important functions of health research system (HRS). In this article, we aimed to reveal the correlation between evaluation of health research organizations and health knowledge production promotion. METHODS: A comprehensive evaluation system was developed to evaluate the academic performance of national medical science universities on an annual basis. It assess following domains; stewardship, capacity building and knowledge production. Measurable indicators for each domain were assigned, a 'research profile' for each department was provided. In this study, we compared the results of annually national Health Research System evaluation findings during 2005-2008. RESULTS: The number of scientific articles has been increased from 4672 to 8816 during 2005 to 2008. It is mentionable that, the number of articles which has been published in indexed data bases has risen too. This fact could be related to directed policy for more international publication of scientific articles from Iran. The proportion of total articles to the number of academic members was 1.14 in 2008, comparing to 0.84 in 2005. It means that this proportion have increased about twice (0.7 Vs 0.45) during mentioned time. Moreover, other scientific products such as authored books based on domestic researches and cited articles in textbooks have increased according to special attention to knowledge production by policy makers. CONCLUSION: We conclude that Health System Research evaluation could be used as a mean for implementing policies and promoting knowledge production.

Correlation between nitrogen fixation rate and alginate productivity of an indigenous Azotobacter vinelandii from Iran.

BACKGROUND AND OBJECTIVES: Azotobacter vinelandii, a gamma-proteobacterium, is an obligate aerobic free-living gram-negative soil bacterium capable of fixing nitrogen. Oxygen transfer rate into the cell is reduced by the increase of alginate concentrations during the course of A. vinelandii cultivation. This phenomenon provides a low intracellular oxygen concentration needed for nitrogenase activity. The aim of this study was to design a simple strategy to explain the alginate production, cell growth and nitrogenase activity correlation in A. vinelandii under aerobic conditions. MATERIAL AND METHODS: Thirty-five different soil samples were taken from the rhizosphere of agricultural crops of Iran. Enrichment and isolation strategies were employed for microbial isolation. Physiological and biochemical characteristics were determined. Molecular identification was performed using selective nifH-g1 primers. Alginate production and nitrogenase activity assay by each isolate of Azotobacter were carried out. Bacterial growth, alginate production and Nitrogenase activity were conducted by time-coursed quantitative measurements. RESULTS: Total of 26 isolates were selected after enrichment, isolation, and screening. The isolate was identified by molecular tests as A. vinelandii. The highest alginate productions of 1.02 g/l and 0.91g/l were noted after 4 days in 8 isolates, cell biomass of which were estimated 4.88-5.26 g/l. Six of 8 isolates were able to fix atmospheric N(2) on nitrogen-free medium. Rates obtained in isolates were in the range of 12.1 to 326.4 nmol C(2)H(4) h(-1) vial(-1). CONCLUSIONS: Nitrogen fixation and alginate production yielded significant and positive Pearson's correlation coefficient of R(2) = 0.760, p ∼ 0.02. Finally association between bacterial growth, alginate production and nitrogenase activity almost noticeable yielded significant and positive Pearson's correlation coefficient R2= 0.723, p ∼ 0.04.

Comparison of 1-periodontal indices and cultural porphyromonas gingivalis colony count in aggressive periodontitis patients treated by scaling and rootplanning with or without metronidazole gel.

OBJECTIVE: Systemic antibiotics and locally applied antimicrobial agents have been suggested to enhance clinical parameters. Patients exhibiting aggressive periodontitis in particular benefit from adjunctive antibiotic therapy. The purpose of this investigation was to evaluate the effect of local antibiotic therapy with metronidazole adjunctively to scaling and root planning (SRP) in the treatment of aggressive periodontitis. MATERIALS AND METHODS: Twenty patients diagnosed with aggressive periodontitis were placed in a spilt mouth design. Microbial specimens were taken from the deepest pocket of the teeth. The sites that had positive results of Porphyromonas gingivalis (P.g) were located randomly to receive SRP treatment in the control group and SRP plus metronidazole gel in the test group. Pocket probing depth (PPD), clinical attachment level (CAL) and bleeding on probing (BOP) parameters and numbers of P.g. colony were taken at baseline, 6 weeks and 12 weeks later. All data were collected and analyzed and tested by Wilcoxon and paired t test. RESULTS: The case group patients had significantly better results in BOP, PPD and the number of P.g colony count reduction in comparison with the control group (p<0.05). According to the measurements of CAL, the statistical difference was non significant (p>0.05). CONCLUSION: In non-surgical periodontal treatment of aggressive periodontits adjunctive metronidazole gel therapy has a better effect on the reduction of porphyromonas gingivalis content of pockets.

Prevalence of mutations at codon 463 of katG gene in MDR and XDR clinical isolates of Mycobacterium tuberculosis in Belarus and application of the method in rapid diagnosis.

Isoniazid (INH) is a central component of drug regimens used worldwide to treat tuberculosis. In respect to high GC content of Mycobacterium tuberculosis, nonsynonymous mutations are dominant in this group. In this study a collection of 145 M. tuberculosis isolates was used to evaluate the conferring mutations in nucleotide 1388 of katG gene (KatG463) in resistance to isoniazid. A PCR-RFLP method was applied in comparison with DNA sequencing and anti-mycobacterial susceptibility testing. From all studied patients, 98 (67.6%) were men, 47 (32.4%) were women, 3% were <15 and 9% were >65 years old; male to female ratio was 1:2.4. PCR result of katG for a 620-bp amplicon was successful for all purified M. tuberculosis isolates and there was no positive M. tuberculosis culture with PCR negative results (100% specificity). Subsequent PCR RFLP of the katG identified mutation at KatG463 in 33.3%, 57.8% and 59.2% of our clinically susceptible, multidrug resistant TB (MDR) and extensively drug resistant (XDR) isolates, respectively. Strains of H37Rv and Academic had no any mutations in this codon. M. bovis was used as a positive control for mutation in KatG463. Automated DNA sequencing of the katG amplicon from randomly selected INH-susceptible and resistant isolates verified 100% sequence accuracy of the point mutations detected by PCR-RFLP. We concluded that codon 463 was a polymorphic site that is associated to INH resistance (a missense or "quiet" mutation). RFLP results of katG amplicons were identical to those of sequence method. Our PCR-RFLP method has a potential application for rapid diagnosis of M. tuberculosis with a high specificity.

Rapid and simple approach for identification of Mycobacterium tuberculosis and M. bovis by detection of regulatory gene whiB7.

Identification of Mycobacterium tuberculosis and M. bovis is necessary for the application of adequate drug therapy. PCR amplification is a good tool for this purpose, but choosing proper target is of a great concern. We describe a PCR assay for fast detection of M. tuberculosis and M. bovis.As a BLAST and BLASTP search we selected regulatory gene whiB7 that encodes multi-drug resistance in this bacterium. Thirty clinical isolates of M. tuberculosis were sequenced and all the mutations in gene whiB7 were detected. The best set of several pairs of primers was selected and used in comparison by rpoB gene for differentiation of M. bovis, M. avium, M. kansasii, M. phlei, M. fortuitum, M. terrae, seven non-pathogenic Mycobacterium isolates and 30 clinical isolates of M. tuberculosis.It was proved that only clinical isolates of M. tuberculosis and M. bovis have positive bands of 667 bp whiB7. Other non-tuberculous and non-pathogenic isolates did not show any positive sign. Furthermore, 667-bp PCR products of whiB7 gene were observed for ten positive sputum samples (preliminarily approved to be positive for M. tuberculosis by commercially real-time based method), but no bands were detected in 5 negative sputum samples. RpoB gene could not differentiate non-tuberculous strains and non-pathogenic isolates from pathogenic clinical isolates. We concluded that PCR amplification of the gene coding for the WhiB7 protein could be successfully used as a good tool for rapid identification of M. tuberculosis and M. bovis. We propose application of this method as a rapid and simple approach in mycobacteriological laboratories.

Normalized impact factor (NIF): an adjusted method for calculating the citation rate of biomedical journals.

The interests in journal impact factor (JIF) in scientific communities have grown over the last decades. The JIFs are used to evaluate journals quality and the papers published therein. JIF is a discipline specific measure and the comparison between the JIF dedicated to different disciplines is inadequate, unless a normalization process is performed. In this study, normalized impact factor (NIF) was introduced as a relatively simple method enabling the JIFs to be used when evaluating the quality of journals and research works in different disciplines. The NIF index was established based on the multiplication of JIF by a constant factor. The constants were calculated for all 54 disciplines of biomedical field during 2005, 2006, 2007, 2008 and 2009 years. Also, ranking of 393 journals in different biomedical disciplines according to the NIF and JIF were compared to illustrate how the NIF index can be used for the evaluation of publications in different disciplines. The findings prove that the use of the NIF enhances the equality in assessing the quality of research works produced by researchers who work in different disciplines.

Isolation of clinical strains of Pseudomonas aeruginosa harboring different plasmids.

Aim of this study was to investigate the presence of plasmids among the strains of P. aeruginosa isolated from clinically diagnosed cases in Tehran in 2006. A total of 38 strains of P. aeruginosa were isolated. With the exception of one isolate, all P. aeruginosa strains harbored at least one plasmid band. The electrophoretic analysis of plasmid DNAs showed different number of plasmid bands among the strains tested. The DNA band of 1.4 kbp was evident in 84.2% of the strains. Approximately 71 and 21% of the isolates harbored concomitantly two and three plasmids, respectively. Isolation of strains with diverse types of plasmids suggests the different cluster of P. aeruginosa might be disseminated during the current study period.

Incidence of enteric adenovirus gastroenteritis in Iranian children.

BACKGROUND: Enteric adenoviruses, i.e. adenovirus 40 (Ad40) and adenovirus 41 (Ad41), have been shown to be a substantial cause of pediatric gastroenteritis in various parts of the world, but no data are available for Iran. OBJECTIVE: The present study was performed to determine the incidence of enteric adenoviruses in children presenting to the Children's Medical Center with gastroenteritis in Iran. STUDY DESIGN: Stool specimens from 872 children less than 7 years of age attending the Children's Medical Center in Tehran, Iran, with gastroenteritis were tested for the presence of Ad40, Ad41, and adenovirus-genus by a monoclonal antibody-based enzyme immunoassay. RESULTS AND CONCLUSION: 6.7% of stool specimens contained enteric adenoviruses (3.3% Ad40 and 3.4% Ad41) and 2.0% nonenteric adenoviruses. Mean ages of Ad40, Ad41 and NEAd-positive children were 21, 19 and 29 months, respectively. Among the adenovirus-positive patients, 53.9% were male and 46.1% female. Watery diarrhea was present in 86.4% of children infected by adenoviruses. In conclusion, for the first time, we demonstrated the presence of enteric and nonenteric adenoviruses in a considerable proportion of stool samples from Iranian children with gastroenteritis.