Emergence of fluoroquinolone resistance and possible mechanisms in clinical isolates of Stenotrophomonas maltophilia from Iran.

Stenotrophomonas maltophilia exhibits wide spectrum of fluoroquinolone resistance using different mechanisms as multidrug efflux pumps and Smqnr alleles. Here, the role of smeDEF, smeVWX efflux genes and contribution of Smqnr alleles in the development of fluoroquinolone resistance was assessed. Ciprofloxacin, levofloxacin and moxifloxacin resistance were found in 10.9%, 3.5%, and 1.6% of isolates, respectively. More than four-fold differences in ciprofloxacin MICs were detected in the presence of reserpine and smeD, F, V expression was significantly associated with ciprofloxacin resistance (p = 0.017 for smeD, 0.003 for smeF, and 0.001 for smeV). Smqnr gene was found in 52% of the ciprofloxacin-resistant isolates and Smqnr8 was the most common allele detected. Fluoroquinolone resistance in S. maltophilia clinical isolates was significantly associated with active efflux pumps. There was no correlation between the Smqnr alleles and ciprofloxacin resistance; however, contribution of the Smqnr genes in low-level levofloxacin resistance was revealed.

Antibiotic stewardship program in Intensive Care Unit: First report from Iran.

INTRODUCTION: Few data regarding antibiotic stewardship programs in critically ill patients are available. In the present study, the consequence of changing an empirical antibiotic regimen from a carbapenem (meropenem) to a noncarbapenem antibiotic (piperacillin-tazobactam) was evaluated in critically ill patients with a suspicion of sepsis. METHODS: This open-label randomized clinical trial was conducted during May 2015-January 2017 at the general Intensive Care Unit of the Imam Khomeini Hospital Complex, Tehran, Iran. In this study, a carbapenem (meropenem) or a noncarbapenem (piperacillin-tazobactam) antibiotic was considered as an empirical antibiotic regimen in 100 critically ill patients with a suspicion of sepsis. Clinical response and bacterial eradication were defined as primary and secondary outcomes of the study, respectively. Chi-square, Mann-Whitney, and independent sample t-tests were used for comparing variables between the groups. ANOVA was used to compare changes in the mean differences of parameters between the groups. Meaningful difference was indicated as P ≤ 0.05. RESULTS: During the first 72 h of the antibiotic course, the number of patients with clinical response was comparable between piperacillin-tazobactam and meropenem groups (21 [42%] and 25 [50%], respectively, P = 0.31). Also, at this time, microbial eradication occurred in 13 (54.16%) and 9 (40.90%) patients in piperacillin-tazobactam and meropenem groups, respectively (P = 0.67). CONCLUSIONS: Using a carbapenem (meropenem) instead of a noncarbapenem (piperacillin-tazobactam) as an empirical antibiotic regimen did not affect clinical response and bacterial eradication rates in critically ill patients with a suspicion of sepsis.

Prevalence of positive autoimmune biomarkers in the brucellosis patients.

Brucellosis is a chronic infectious disease with articular involvement. Discrimination between brucellosis and rheumatologic disorders is difficult in regions endemic for brucellosis. There are few studies about the rate of positive autoantibodies as rheumatologic biomarkers in brucellosis, and the prevalence is variable. In this study, the rheumatologic tests were studied in brucellosis patients. This cross sectional study was performed in two teaching hospitals in Tehran, Iran. Forty-nine patients with brucella infection and 42 healthy participants were enrolled in this study. Brucellosis was diagnosed on the basis of the clinical symptoms and positive serology for brucellosis. Rheumatic factor (RF) and antinuclear antibodies (ANA) were evaluated in all patients. Cyclic citrullinated peptides antibody (ACPA) and anti-double strand DNA (anti-dsDNA) were checked in all patients and control groups. Out of 49 patients, 15 (30.6 %) were RF positive and 4 (8.2 %) were ANA positive. Anti-dsDNA was concurrently positive with ANA in 1 patient (2 %) but ACPA titer was positive in 8 patients (16.3 %). None of the patients with positive autoantibody biomarkers fulfilled the criteria for rheumatologic disorders. The rate of positive RF in healthy people was significantly lower than patient group (2.4 vs. 30.6 %), but the positiveness rate of other biomarkers did not have significant difference in two groups. Sixty percent of the patients with positive RF and 75 % with positive ACPA had skeletal involvement (P < 0.05). Autoantibody biomarkers can be positive in brucellosis. Rheumatologists should be aware of brucellosis in patients with musculoskeletal involvement and positive autoantibody biomarkers in endemic regions.

Determination of the accuracy and optimal cut-off point for ELISA test in diagnosis of human brucellosis in Iran.

In endemic area the most challenging problem for brucellosis is to find a reliable diagnostic method. In this case-control study, we investigated the accuracy of ELISA test for diagnosis of human brucellosis and determined the optimal cut-off value for ELISA results in Iran. The laboratory diagnosis of brucellosis was performed by blood isolation of Brucella organism with a BACTEC 9240 system and/or detection of Brucella antibodies by standard agglutination test (titer ≥ 1:160). Serum level of ELISA IgG and ELISA IgM from 56 confirmed cases of brucellosis and 126 controls were compared with each other by Box plot graph and Receiver Operating Characteristic (ROC) curve. Box plot graphs showed the high degree of dispersion for IgG and IgM data in patients compared with all controls. We observed partially overlapping for IgM data (not for IgG) between cases and controls in graphs. The area under ROC curve for distinguishing between cases and controls was larger for IgG compared to IgM. Based on results of this study, ELISA IgG test was more reliable than ELISA IgM test in diagnosis of human brucellosis in Iran. Using a cut-off of 10 IU/ml and 50 IU/ml had most sensitivity (92.9%) and most specificity (100%) for ELISA IgG test, respectively.