Objective As an opportunistic pathogen, Staphylococcus aureus is associated with serious nosocomial infections and growing antimicrobial resistance against beta-lactams among S. aureus strains has become a global challenge. The current study was designed to investigate the presence of agr genes among S. aureus strains recovered from clinical samples in university hospitals of Isfahan and Shahrekord. Results A total of 150 S. aureus isolates were screened by Disk diffusion method (DDM) and conventional PCR. The minimum (17.3%) and maximum (46%) antibiotic resistance rates were found in vancomycin and cefoxitin, respectively. The majority of our isolates were classified as agr type I followed by type II, type IV, and type III. The statistical analysis showed a significant correlation between agr type I and antibiotic resistance against cefoxitin and erythromycin (p = 0.04 and p = 0.03, respectively). Based on our findings, the agr typing could be considered an effective approach for molecular tracking of S. aureus infections.

Objective Mycoplasma pneumoniae, which causes atypical pneumonia, is a well-established pathogen of the respiratory tract. This bacteria is intrinsically susceptible to fluoroquinolones. But Recently, drug-resistant forms of this bacteria have been reported. This study aims to determine the prevalence of this bacteria by ELISA and PCR and MIC to ciprofloxacin. Methods The clinical samples (blood and nasopharyngeal swab) were collected from 100 patients who were referred to selective hospitals in Tehran with respiratory complaints were enrolled in 2017.Nasopharyngeal swab sample collections were cultured on PPLO broth and PPLO agar. After culturing and DNA extraction, PCR was performed by specific P1 genes primers. Ciprofloxacin's MIC of Mycoplasma pneumonia isolated was determined by Micro-broth dilution method. Also, measure serum IgG antibody titers were measured by ELISA Mycoplasma pneumonia. Results In this study, out of 100 samples 12, bacteria were isolated on PPLO agar.Using specific primers,7 samples of Mycoplasma speciesism-specific were positive for the presence of M.pneumoniae. 2 Ciprofloxacin resistant isolates were evaluated. ELISA results show that the IgG titre antibody In 19 samples is existent. Also,5 samples are intermediate. IgG antibody titre average in the whole sample is 27/66 U/ml but it is in Positive samples by P1 PCR is 45/75 U/ml. Conclusions This study showed that PCR is a sensitive and reliable method for rapid detection of M. pneumoniae bacteria in respiratory infectious samples.but the results of this method are different from the ELISA method. also, It seems that the Resistance to ciprofloxacin is relatively common among M. pneumoniae.

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