Hassan Mahmoudi , Mohammad Reza Arabestani , Seyed Fazlullah Mousavi , Safiyeh Ghafel , Mohammad Yousef Alikhani ,
Volume 73, Issue 1 (April 2015)
Abstract
Background: Staphylococcus aureus is the most important cause of nosocomial infections acquired in the community. Protein A is a major component of Staphylococcus aureus cell wall. In analysis of the nucleotide sequence Protein A encoding spa, locus x consists of 24 base pairs which repeat with high polymorphism. In this study, the spa gene of Staphylococcus aureus isolated from clinical specimens were obtained from patients admitted to the hospital and healthy carriers. Methods: In a cross-sectional study, a total of 200 samples were collected. One hundred fifty samples were obtained from hospitalized patients and 50 samples obtained from staff nasal swabs in Hamadan University Hospitals from October 2013 to August 2014. Disk diffusion antibiotic susceptibility tests performed. The antibiotics studied were Vancomycin (30 µg), Cefoxitin (15 µg) Gentamicin (10 µg), Tetracycline (30 µg), Trimethoprim/sulfamethoxazole (25 µg), Ciprofloxacin (5 µg), Erythromycin (15 µg), Clindamycin (2 µg), Rifampin (5 µg). The tests performed according to the guidelines of clinical and laboratory standards institute (CLSI). It also detect the mecA gene of Methicillin-resistant Staphylococcus aureus strains (MRSA) and genes spa which encodes the protein A by polymerase chain reaction (PCR). The PCR products using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with enzyme Rsa I (Afa I) were prepared. Results: This methicillin-resistant Staphylococcus aureus strain (MRSA) had the highest sensitivity and resistance to ciprofloxacin and clindamycin. Totally, 8 amplicon with different sizes for the spa gene were identified. A total of 9 patterns polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) were found. Some of these patterns between Staphylococcus aureus isolated from clinical specimens and nasal carriers were common. Conclusion: There is a similar pattern of spa gene among patients admitted to the hospital and staff, according to our findings. Analysis of the patterns can reduced transmission of infection in both hospital staff and patients. Also it can help the physicians for correct management of infections.
Mohammad Reza Arabestani , Sahar Rastiany, Seyed Fazlullah Mousavi , Safiyeh Ghafel , Mohammad Yousef Alikhani,
Volume 73, Issue 8 (November 2015)
Abstract
Background: Staphylococcus aureus is one the most common pathogens causing community-acquired infections and a major concern for public health, and the other hands antibiotic resistance is also of great concern for public health authorities also Staphylococcus aureus produce a lot of virulence factors such as variety of exoproteins included toxic shock syndrome and exfoliative toxin which causes colonization and different infections in their host. The aims of current study were to evaluate the prevalence of Toxic shock syndrome toxin 1 (TSST-1) and ETs genes in isolated S. aureus strains using polymerase chain reaction (PCR) assay. Methods: This cross-sectional study was performed on 100 methicillin-resistant staphylococcal aureus (MRSA) and 100 methicillin-sensitive staphylococcal aureus (MSSA) isolated from clinical specimens of inpatients, outpatients hospitals and nasal carriers in Hamadan University from October 2013 to August 2014. Identified species by biochemical methods were confirmed by the PCR method. Antibiotic resistance was performance by disk diffusion and the presence of TSST-1 and ETs genes was investigated using PCR. Results: Of the 100 isolates MRSA examined, the most frequent resistance was observed to ciprofloxacin (95%), followed by tetracycline (91%), erythromycin (92%), Gentamicin (90%), Rifampin (85%), trimethoprim-sulfamethoxazole (85%), clindamycin (80%) and cefoxitin (100%). Of the 100 isolates MSSA examined, the most frequent resistance was observed to erythromycin (68%), ciprofloxacin (66%), followed by tetracycline (52%), gentamicin (25%), clindamycin (46%), rifampin (45%), trimethoprim-sulfamethoxazole (66%) and cefoxitin (0%). Prevalence of TSST-1 and ETs genes were determined 13% (n=26) isolates, totally. Also the prevalence of TSST-1 was 11% (n=22) and ETs genes was 2% (n=4) isolates and none of the investigated isolates carried eta gene. Conclusion: The increasingly prevalence of MRSA and emerging its antibiotic resistance in clinical isolates can be considered a serious problem for public health. Detection of the high rate prevalence of TSST genes in current study is considered as a serious problem and existing and circle of these strains in according to colonization in community especially old people and immunocompromised patients is very serious.
