Introduction: Burns are the most serious forms of trauma and a major cause of mortality worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of burn wound infections; treatment has faced serious problems due to antibiotic resistance in these strains. Biofilm formation, which increases antibiotic resistance capabilities and is considered to be a virulence factor, also causes treatment failure and recurrent staphylococcal infections in burn patients. Methodology: A total of 135 pus/wound swabs were collected; S. aureus was identified by confirmatory tests. The icaA/D and mecA genes were detected in DNA extracts by polymerase chain reaction assay separately. To determine the prevalence of biofilm formation, a modified Congo red agar and the microtiter plate method were used. Investigation of antibiotic resistance was performed using the disk diffusion method. Results: S. aureus (48.87%) was identified in 65 (48.87%) samples, of which 40 (61.53%) were confirmed to be MRSA. Among MRSA and methicillin-sensitive S. aureus (MSSA) isolates, 97.5% and 60% produced biofilm, respectively. Resistance of MRSA isolates to amikacin, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, mupirocin, rifampin, tetracycline, and tobramycin was 64.1%, 76.92%, 51.28%, 87.18%, 71.8%, 10.26%, 5.13%, 89.74%, and 61.54%, respectively. All MRSA and MSSA isolates were susceptible to fusidic acid, linezolid, teicoplanin, tigecycline, and vancomycin. Conclusions: The high prevalence of biofilm-producing, drug-resistant S. aureus isolates in our study suggests that epidemiological studies on the characteristics of common strains found in burn centers and a definition of their antibiotic resistance pattern would be helpful for therapeutic decisions.

Background: The aim of this study was to assess associations of Citrobacter freundii foodborne outbreaks with environmental factors in various regions of Yazd Province, Iran, 2012–2016. Methods: The public health surveillance data were used for one period of five years reported foodborne disease outbreaks in various regions of the Province. Multilevel regression statistical method was used to analyze associations of climatic and demographic variables with outbreaks. Significant associations were tested using likelihood ratio tests. Results: Results showed a significant association between C. freundii outbreaks and air dust conditions, age groups and various regional cities. Conclusion: The current study revealed necessity of etiologic agent identification for use in foodborne disease outbreak guidance in future outbreaks. Systemic surveillance schemes can help prevent and control similar scenarios using reports of environmental effects on foodborne disease outbreaks.

Among many pneumococcal antigens, choline-binding proteins (CPBs) display a high immunogenicity in animal models. This study aims to determine the immunogenicity of CbpM, CbpG and CbpL proteins of Streptococcus pneumoniae in a mice model. The genes were cloned into pET21a expression vector and the recombinant proteins were produced. Mice were immunized with the purified recombinant proteins. Subsequently, the mice were challenged with S. pneumoniae ATCC 49619 (2×106 CFU) and their survival and bacterial clearances were followed 24 hours after infection. The antibody responses of the mice were determined by ELISA assay. The opsonophagocytosis assay was performed using rabbit’s sera. Passive immunization was carried out using two doses of anti-CbPs antibodies. Finally, these mice were  experimentally infected with virulent bacteria and the protective effects of two doses of 10 and 100 µg/mL by monitoring the survival rate and bacterial clearance were determined at 2, 3 and 7 days after bacterial challenge. The mice actively immunized with CbpM, CbpG and CbpL recombinant proteins showed survival rate of 100%, 85% and 75%, respectively. The survival rates among passively immunized mice groups which received100 µg/mL dose of anti-CbpM, anti-CbpG and anti- CbpL were 50%, 50% and 25%, respectively. The rates of opsonization with rabbit’s antibodies against CbpM, CbpG, and CbpL  at 100 µg/mL doses was 45.6%, 14.7% and 82.3%, and at 10 µg/mL was 12.9%, 12.2% and 9.35%, respectively. Our findings suggest that the recombinant proteins particularly CbpM and CbpG can protect the mice against pneumococcus19F serotype and effectively induce a protective antibody response. Thus, CbpG and CbpM proteins might be used as suitable vaccine candidate in pneumococcal vaccine formulations.

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