Synergistic Antibacterial Activity and Wound Healing Properties of Selenium-Chitosan-Mupirocin Nanohybrid System: An in Vivo Study on Rat Diabetic Staphylococcus aureus Wound Infection Model.

The current study aimed to formulate Selenium-Chitosan-Mupirocin (M-SeNPs-CCH) complex. The nanohybrid system was prepared using chitosan-cetyltrimethylammonium bromide (CTAB)-based hydrogel (CCH) that entrapped mupirocin (M) and selenium nanoparticles (SeNPs). The in vitro studies were performed by evaluation of the antibacterial activity and toxicity on L929 mouse fibroblast cell line. The in vivo study was conducted on rat diabetic wound infection model that was infected by mupirocin-methicillin-resistant Staphylococcus aureus (MMRSA). The wounds were treated by M-SeNPs-CCH nanohybrid system with concentrations of M; 20 mg/ml, CCH; 2 mg/ml and SeNPs; 512 µg/ml in two times/day for 21 days. The therapeutic effect of this nanohybrid system was evaluated by monitoring wound contraction and histopathological changes. Evaluation of the average wound healing time showed a significant difference between the treatment and control groups (P≤0.05). The histopathological study indicated that the amount of wound healing was considerable in M-SeNPs-CCH nanohybrid system groups compared to the control and M groups. The M-SeNPs-CCH nanohybrid system formulated in this study was able to reduce 3-fold MIC of mupirocin with synergistic antibacterial activity as well as to play a significant role in wound contraction, angiogenesis, fibroblastosis, collagenesis, proliferation of hair follicle, and epidermis growth compared to the control group (P ≤ 0.05). This research suggests that this nanohybrid system might be a development for the treatment of diabetic wound infection at mild stage.

First evidence of the presence of adenovirus type 8 in myocardium of patients with severe idiopathic dilated cardiomyopathy.

Previous studies have detected adenovirus and cytomegalovirus (CMV) in cardiac tissue of patients with myocarditis. Therefore, in this study, we investigated the frequency of these viruses, which may be involved in the development of severe dilated cardiomyopathy (DCM). Myocardial tissue from of 23 cardiac transplant candidates with acute idiopathic DCM below the age of 40 years were analyzed by amplification of adenovirus and CMV DNA and subsequent sequencing. Adenovirus was detected in four (17.4%) and CMV in one (4.3%) of the patients. All controls were negative for the presence of both viruses. Our study shows that myocardial infection with adenovirus may play an important role in the pathogenesis of severe DCM and suggests that vaccination against adenovirus might be helpful in decreasing the prevalence of severe idiopathic DCM. This is the first study in which adenovirus type 8 has been detected in the hearts of patients with DCM.

Carriage rates of Neisseria meningitidis serogroups: determination among freshmen conscripts before vaccination.

BACKGROUND AND OBJECTIVES: Neisseria meningitidis is transmitted from person-to-person. Thus, close contact with a healthy carrier can facilitate the spread of the bacteria and lead to life-threatening meningococcal disease. The aim of this study was to identify oropharyngeal carriers of N. meningitidis in volunteers preparing for military service before vaccination. MATERIALS AND METHODS: In a cross-sectional study, 226 volunteers entering military service were referred to the Shemiranat Health Center for meningococcal vaccination and assayed. Before vaccination, the participants underwent sampling of the throat using separate swabs. Thayer-Martin Agar medium and microbiological standard methods were used for culture and isolation of the organisms. The bacterial isolates were subjected to DNA extraction and polymerase chain reaction. The obtained data were descriptively analyzed. RESULTS: Out of the 226 (100%) young volunteers, only 18 (8%) yielded Gram-negative diplococci. The results showed the presence of N. meningitidis (carriage rate: 8%) in their oropharyngeal regions. The isolated serogroups were C, A, Y, W-135, and X with frequencies of 50, 22.2, 16.6, 5.5, and 5.5, respectively. DISCUSSION: This study showed that the carriage rate in young volunteers for military service is around 8% before vaccination. Although the rates for serogroups A and C were dominant, the existence of serogroups Y and W indicate the necessary revision of the A/C vaccine. More research is needed to determine serogroup diversity and decrease the risk of meningococcal disease in individual groups.

Evaluate the Relationship Between Class 1 Integrons and Drug Resistance Genes in Clinical Isolates of Pseudomonas aeruginosa.

BACKGROUND: The prevalence of resistant Pseudomonas aeruginosa isolates is increasing and it is considered as one of the major public health concerns in the world. The association between integrons and drug resistance has been proven and evidences suggest that integrons are coding and responsible for dissemination of antibiotic resistance among P. aeruginosa isolates. OBJECTIVE: This study is aimed to evaluate the relationship between class 1 integrons and drug resistance genes in clinical isolates of P. aeruginosa from burn patients. METHODS: 100 isolates of P. aeruginosa were collected from burn patients hospitalized in the skin ward of Shahid Motahari hospital and susceptibility testing was performed by disk diffusion method (Kirby-Bauer). Then DNA was extracted and PCR technique was performed for the detection of class 1 integrons and drug resistance genes. Then data was analyzed using SPSS software. RESULTS: The most effective antibiotic was polymyxin B with sensitivity 100%, and the most resistance was observed to the ciprofloxacin (93%) and amikacin (67%), respectively. The maximum and lowest frequencies of drug resistance genes belonged to the aac (6 ') - 1, VEB-1 with prevalence rate 93% and 10%, respectively. The statistical Chi-square test did not find any significant correlation between class 1 integrons and drug resistance genes (p˃ 0.05). CONCLUSION: Although no significant correlation between class 1 integrons and drug resistance was observed, but the resistance rate to antibiotics tested among P. aeruginosa isolates was high. So, surveillance, optimization and strict consideration of antimicrobial use and control of infection are necessary.

An observational study on infective endocarditis: a single center experience.

BACKGROUND: Cloning of microorganisms on heart endothelium can lead to infective endocarditis (IE). The prototypic lesion of infective endocarditis, the vegetation is a mass of platelets, fibrin, microcolonies of microorganisms, and scant inflammatory cells. OBJECTIVES: The aim of this study was to evaluate patients with IE and also focusing on echocardiographic data and comparison between TTE (transthoracic echocardiography) and TEE (transesophageal echocardiography) of native and prosthetic valve endocarditis and the final impact of IE (infective endocarditis) in these patients with endocarditis. PATIENTS AND METHODS: All patients with IE admitted to our center between 2007 and 2010 were studied. All echocardiographies were performed by the same echocardiographer. Echocardiography and lab tests were performed for all patients. We used SPSS 16 for data analysis. RESULTS: We studied 35 patients, 45% male and 55% female with a mean age of 56.36 ± 12.44 years. Fever (80%) and chills (65.7%) were the most common symptoms. There was only a positive blood culture and enterococci sensitive to vancomycin and amoxicillin. The most involved valve was mitral (54.2%) and then aortic valve (48.5%) (two patients had vegetation on both aortic and mitral valves). In this study, specificity and sensitivity of TEE were 100% and 88.6%. Six patients (17.1%) died and six patients needed surgery. CONCLUSIONS: Endocarditis is an important disease with a high mortality rate if not treated appropriately. Therefore, these patients need more attention. In echocardiography, vegetation and complications of IE such as abscess and paravalvular leakage can be detected.