Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). The major pathological outcomes of the disease are the loss of blood-brain barrier (BBB) integrity and the development of reactive astrogliosis and MS plaque. For the disease to occur, the non-resident cells must enter into the immune-privileged CNS through a breach in the relatively impermeable BBB. It has been demonstrated that matrix metalloproteinases (MMPs) play an important role in the immunopathogenesis of MS, in part through the disruption of the BBB and the recruitment of inflammatory cells into the CNS. Moreover, MMPs can also enhance the cleavage of myelin basic protein (MBP) and the demyelination process. Regarding the growing data on the roles of MMPs and their tissue inhibitors (TIMPs) in the pathogenesis of MS, this review discusses the role of different types of MMPs, including MMP-2, -3, -7, -9, -12 and -25, in the immunopathogenesis and treatment of MS.

Staphylococcus aureus is a major hospital and community pathogen having the aptitude to cause a wide variety of infections in men. The ability of microorganisms to produce biofilm facilitates them to withstand the host immune response and is recognized as one factor contributing to chronic or persistent infections. It was demonstrated that the ica-encoded genes lead to the biosynthesis of polysaccharide intercellular adhesion (PIA) molecules, and may be involved in the accumulation phase of biofilm formation. Different studies have shown the decisive role of the ica gene as virulence factors in staphylococcal infections. This study was carried out to demonstrate the relationship between ica gene and production of slime layer in S. aureus strains. Sixty S. aureus strains were isolated from patients. The isolates were identified morphologically and biochemically following standard laboratory methods. After identification, the staphylococcal isolates were maintained in trypticase soy broth (TSB), to which 15% glycerol was added, and stored at -20°C. Slime formation and biofilm assay was monitored. A PCR assay was developed to identify the presence of icaD (intercellular adhesion gene) gene in all isolates. Thirty-nine slime producing colonies with CRA plates (65%) formed black colors, the remaining 21 isolates were pink (35%). In the quantitative biofilm assay 35 (58%) produced biofilm while 25 (42%) isolates did not exhibit this property. All isolates were positive for detection of icaD gene by PCR method. The interaction of icaA and icaD in the investigated isolates may be important in slime layer formation and biofilm phenomena. We propose PCR detection of the ica gene locus as a rapid and effective method to be used for discrimination between potentially virulent and nonvirulent isolates, with implications for therapeutic and preventive measures pertainin to the management of colonized indwelling catheters.

Background: Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity. Objectives: This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates. Materials and Methods: One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods. Results: A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem. Conclusions: Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics. Keywords: Surgical Site Infections; Antibiotic Susceptibility Pattern; Polymicrobial Infection; Minimal Inhibitory Concentration

Multidrug‐resistant pathogens are one of the common causes of death in burn patients and have a high risk of nosocomial infections, especially pneumonia, urinary tract infections, and cellulitis. The role of prolonged hospitalization and empirical antibiotics administration in developing multidrug‐resistant pathogens is undeniable. In the early days of admitting burn patients, Gram‐positive bacteria were the dominant isolates with a more sensitive antibiotic pattern. However, the emergence of Gram‐negative bacteria that are more resistant later occurs. Trustworthy guideline administration in burn wards is one of the strategies to prevent multidrug‐resistant pathogens. Also, a multidisciplinary therapeutic approach is an effective way to avoid antibiotic resistance that involves infectious disease specialists, pharmacists, and burn surgeons. However, the emerging resistance to conventional antimicrobial approaches (such as systemic antibiotic exposure, traditional wound dressing, and topical antibiotic ointments) among burn patients has challenged the treatment of multidrug‐resistant infections, and using nanoparticles is a suitable alternative. In this review article, we will discuss different aspects of multidrug‐resistant pathogens in burn wounds, emphasizing the full role of these pathogens in burn wounds and discussing the application of nanotechnology in dealing with them. Also, some advances in various types of nanomaterials, including metallic nanoparticles, liposomes, hydrogels, carbon quantum dots, and solid lipid nanoparticles in burn wound healing, will be explained.

Burn patients are at high risk of developing nosocomial infection because of their destroyed skin barrier and suppressed immune system, compounded by prolonged hospitalization and invasive therapeutic and diagnostic procedures. Studies on nosocomial infection in burn patients are not well described. The objective of the present study was to identify the causative bacterial of nosocomial infection and to determine the incidence of nosocomial infection and their changing during hospitalization in burned patients admitted to in the Motahari Hospital, Tehran, Iran. During the second part of 2010, 164 patients were included in this study. Samples were taken the first 48 hours and the fourth week after admission to Motahari Burn hospital. Isolation and identification of microorganisms was performed using the standard procedure. Of the 164 patients, 717 samples were taken and 812 bacteria were identified, 610 patients were culture positive on day 7 while 24 (17.2%) on 14 days after admission. The bacteria causing infections were 325Pseudomonas, 140Acinetobacter, 132 Staphylococcus aureus, and 215 others. The percentage of mortality was 12%. All of patients had at least 1 positive culture withPseudomonasand/or withAcinetobacter. Hospitals suggest continuous observationof burn infections and increase strategies for antimicrobial resistance control and treatment of infectious complications.

Objective: Coagulase-negativestaphylococci(CoNS) are as considered opportunistic pathogens which capable of producing several toxins, enzymes and resistance genes. The current study aimed to determine the occurrence of different hemolysins genes and patterns of antibiotic resistance among CoNS species.Results: The highest frequency of antibiotic resistance was observed against cefoxitin in 49 isolates (53.8%), and the lowest resistance was against novobiocin in 5 isolates (5.5%). None of the isolates was resistant to vancomycin. The prevalence ofhla, hla_yidD, hld,andhlbgenes was: 87.9%, 62.6%, 56%, and 47.3%, respectively. Thehla/yidDandhldgenes were detected in 69.4% ofS. epidermidisand thehlagene in 94.6% ofS. haemolyticusisolates; thehlbgene was detected in 53.1% of theS. epidermidisisolates. ThemecAgene was identified in 50 (55%) of the CoNS isolates. In conclusion, the results of statistical analysis showed that thehld genehad a significant association with resistance to levofloxacin and erythromycin antibiotics, thehlbwith clindamycin resistance and thehla/yidDwith rifampicin and novobiocin resistance. The results of this study showed that there is a significant relationship between hemolysin encoding genes and antibiotic resistance patterns; therefore, detection of virulence factors associated with antibiotic resistance has become a significant issue of concern.