Genetic Variability of Methicillin Resistant Staphylococcus Aureus Strains Isolated from Burns Patients

OBJECTIVES: Staphylococcus aureus is a nosocomial pathogen that provides a major challenge in the healthcare environment, especially in burns units where patients are particularly susceptible to infections. In this study, we sought to determine molecular types of S. aureus isolates collected from burns patients, based on staphylococcal protein A and coagulase gene polymorphisms. METHODS: Antibiotic susceptibility testing of 89 S. aureus strains isolated from burn wounds of patients was assessed using the Kirby-Bauer disk diffusion method. Strains were characterized by spa typing, coa typing, and resistance and toxin gene profiling. RESULTS: A total of 12 different spa types were identified with the majority being t790 (18%). Panton-Valentine leucocidin encoding genes were identified in spa types t044 (5.6%), t852 (2.2%) and t008 (2.2%). The most commonly detected antibiotic resistance gene was ant (4′)-Ia (60.7%). Ten different coa types were detected and the majority of the tested isolates belonged to coa III (47.2%). All the high-level mupirocin-resistant and low-level mupirocin resistant strains belonged to coa type III. CONCLUSION: The present study illustrated that despite the high frequency of coa III and spa t790 types, the genetic background of S. aureus strains in Iranian burns patients was diverse. The findings obtained are valuable in creating awareness of S. aureus infections within burns units.

Natural Infection with Rabies Virus: A Histopathological and Immunohistochemical Study of Human Brains

OBJECTIVES: Despite all the efforts and increased knowledge of rabies, the exact mechanisms of infection and mortality from the rabies virus are not well understood. To understand the mechanisms underlying the pathogenicity of rabies virus infection, it is crucial to study the tissue that the rabies virus naturally infects in humans. METHODS: Cerebellum brain tissue from 9 human post mortem cases from Iran, who had been infected with rabies virus, were examined histopathologically and immunohistochemically to evaluate the innate immune responses against the rabies virus. RESULTS: Histopathological examination revealed inflammation of the infected cerebellum and immunohistochemical analyses showed an increased immunoreactivity of heat shock protein 70, interleukin-6, interleukin-1, tumor necrosis factor-alpha, caspase-3, caspase-9, toll-like receptor3 and toll-like receptor4 in the infected brain tissue. CONCLUSION: These results indicated the involvement of innate immunity in rabies infected human brain tissue, which may aggravate the progression of this deadly disease.

Survey of clinical features, pathogenesis and therapeutic options for Ebola haemorrhagic fever

The genus Ebola virus first was recognized in 1976, when two outbreaks occurred in Zaire and Sudan. Ebola virus disease [EVD] is a highly contagious disease that can affect both human and nonhuman primates: Zaire ebolavirus [ZEBOV], Sudan ebolavirus [SEBOV], Côte d'Ivoire ebolavirus [CEBOV], Bundibugyo ebolavirus [BEBOV] and Reston ebolavirus [REBOV] are five members of the Filoviridae family that can cause haemorrhagic fever. EVD is transmitted by direct contact with contaminated blood or other biological fluids of the infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest. Ebola is responsible for different clinical futures that can be ranged from fever, headache, arthralgia, myalgia, abdominal pain, anorexia and vomiting to severe respiratory disorders, viral hemorrhagic fever, cardio-vascular disorders and hypovolaemic shock. Although there is no specific treatment for EVD, considerable advances like use of monoclonal antibody, intefron and Favipiravir/T-705 as effective chemotherapeutic agent in treatment of EBV have been made. To date, 25 outbreaks of EVD have been reported. Hence, EVD as a zoonotic disease should be more focused not only in endemic area but also in throughout the world. Awareness of the disease and routes of transmission and also continuous surveillance to combat disease and outbreaks is necessary

Further stimulation of cellular immune responses through association of HPV-16 E6, E7 and L1 genes in order to produce more effective therapeutic DNA vaccines in cervical cancer model

Cervical cancer has been shown to be highly associated with human papillomavirus [HPV] infection. The viral oncogenes E6 and E7 are constantly expressed by the tumor cells and are therefore potent targets for therapeutic genetic vaccination. In the present study, it was investigated the potential effect of HPV-16 E6, E7 and L1 co-administration to activate specific cytotoxic T lymphocytes in tumor mice models. The HPV-16 E6, E7 and L1 genes from Iranian isolate were separately inserted into the mammalian expression vector, pcDNA3, to construct the DNA vaccine candidates. Tumor-bearing Animals [C57BL/6 mice] were immunized with the vaccine candidate; then, Lymphocyte Proliferation Assay [LPA] and relative tumor volume measurements were carried out in order to examine the immunological effects of the vaccine. Obtained results showed that co-administration of the HPV-16 E6, E7 and L1 DNA induced HPV-16 specific cellular immune responses and also protected against TC-1-induced tumor in vivo compared with negative controls. The results showed that mixed delivery systems might be valuable to improve the magnitude of the induced immune responses and confirmed therapeutic effects of HPV-16 E6, E7 through cytotoxic T lymphocyte induction and illustrate the new promising role for HPV-16 L1 CTL epitopes as a suitable CTL inducer

Construction of an eGFP expression plasmid under control of T7 promoter and IRES sequence for assay of T7 RNA polymerase activity in mammalian cell lines

Recently, the use of T7 RNA polymerase instead of other viral and cellular promoters is increasing due to high efficacy of transcription in the cell cytoplasm by this polymerase. In order to translate the transcripts produced by T7 RNA polymerase in mammalian cell lines, it is necessary to include Internal Ribosome Entry Site [IRES] sequences. In addition, if sequence of poly A signal would be included after interested gene, the rate of expression could be increased in the cells. For expression of eGFP in HEK-293 and T7-BHK cells by T7 RNA polymerase, the sequence of eGFP as well as IRES sequences upstream of eGFP gene and poly A signal were inserted into a pUC57 plasmid. On the other hand, gene of T7 RNA polymerase was cloned into modified pIRES2-EGFP plasmid. Then, the constructed plasmids were transfected into HEK-293 cells. T7-BHK cell was used for control of T7 RNA polymerase activity. Our results showed that using T7 RNA polymerase for expression of foreign genes in mammalian cell lines is highly efficient. Highly efficient eGFP expression in HEK-293 cells showed that T7 RNA polymerase could be used for cytoplasmic RNA transcription such as production of anti-cancer proteins and oncolytic viral genomic RNA by reverse genetics

Efficacy of HPV-16 E7 based vaccine in a TC-1 tumoric animal model of cervical cancer

The human papillomavirus as an etiological agent of cervical cancer does not grow adequately in tissue culture systems. The tumor cell line TC-1 continuously expresses the E6 and E7 oncogenic proteins of HPV, and is considered a suitable tool in laboratory investigations and vaccine researches against cervical cancer The TC-1 cell line was grown in RPMI 1650 supplemented with 10% FBS, glutamine and antibiotics, and was used for tumor development in mice. Six to seven week-old tumor bearing C57BL/6 mice were divided into 3 groups consisting of 7 mice per group. The first group received pcDNA-E7, the second group received pcDNAS, and the third group received phosphate buffered saline [PBS]. The treated animals were monitored for their tumor size progression and survival. At last, the tumoric tissues from autopsied animals were fixed and examined with Mayer's hematoxylin and eosin [H and E]. All experiments were done in accordance with guidelines of the Laboratory Animal Ethical Commission of Tarbiat Modares University. Data analysis was performed using the oneway ANOVA followed by Tukey's test in both experimental and control groups. A p-value <0.05 was considered significant. There were significant decreases in tumor growth; there were also improvements in survival among mice in the treated groups [p<0.041]. H and E stained sections from untreated mice were studied independently in a blinded fashion by two observers and showed malignant neoplasms composed of severely pleomorphic tumor cells with nuclear enlargement, high nuclear-cytoplasmic [N/C] ratios, and prominent nucleoli in solid and fascicular patterns of growth. High mitotic activity with extensive necrosis was also noted in both test and control groups. The TC-1 lung metastatic model can be used to test the efficacy of various E7-based therapeutic cancer vaccine strategies for cervical cancer and the prevention of HPV-related neoplasia

[Comparing efficacy of two different hormonal therapy regimen on activity of coagulation factors VII, VIII, IX and serum lipids in menopaused women]

Background: during extrinsic coagulation pathway, a complex is developed between factor VII, calcium and tissue factor [a cell membrane lipoprotein that is exposed after cell injury]. Factor VII needs calcium and vitamin K for its biologic activation. Coronary artery disease can be induced by increased level and activity of the coagulation factors VII, VIII and IX. In postmenopausal period, estrogen can decrease blood lipids and thereby decreases risk of coronary artery disease. However, the exact effects of the estrogen on the other predisposing factors of the coronary artery diseases are unknown. Our objective in this study was to evaluate the effects of oral hormone therapy regimen on fibrinogen and other coagulation factors

Methods: 60 menopause women with history of hysterectomy were randomly allocated in 2 groups. One group was treated with conjugated estrogen 0.625mg/day and the other group was treated with conjugated estrogen 0.625mg/day and medroxy progesterone 2.5mg/day. Serum fibrinogen level and activity of coagulation factors VII, VIII and IX and blood lipids level were checked before and 3 months after treatment

Results: in the estrogen alone treated group, mean of factor VII activity showed significant elevation 3 months after treatment as compared with prior to hormone therapy[p<0.05]. There were no significant changes in means of coagulation factors VIII, IX activities and serum fibrinogen level in estrogen medroxy progesterone treated patients before and after treatment [p>0.05]. In both groups, honi1one therapy significantly decreased serum cholesterol level and LDL-C and increased HDL-C [p>0.00] but the serum triglyceride level was increased in the estrogen alone treated group

Conclusion: significant elevation of coagulation factors VII with significant elevation of serum triglyceride in estrogen treated patients is explainable. This study confirms that hormone therapy with this protocol does not change serum fibrinogen mean and activity of coagulation factor VIII and IX. This finding may be real or may be related to inadequacy of samples regarding the wide normal range of coagulation factors and serum fibrinogen. Studies with more prolonged follow-up or more samples are suggested