Document Type : Original Article (s)
Authors
1
Associate Professor, Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran
2
Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran
3
Department of Microbiology, Young Researchers' Club, Jahrom Branch, Islamic Azad University, Jahrom, Iran
Abstract
Background: A major concern about S. pneumoniae is the emergence of resistance to antibiotics, especially to penicillin. The aim of this study was to assess the role of PBPs gene in penicillin resistance of S. pneumoniae strains isolated from two intensive care units (ICUs).. Methods: This cross-sectional study was carried out on 62 samples suspected to S. pneumoniae isolated from patients who were admitted to ICUs of Namazi and Shahid Faghihi Hospitals, Shiraz, Iran, in 2010-2011. At first suspected colonies were identified by phenotypic and chemical tests. Organisms were confirmed to be S. pneumoniae on the basis of the presence of lytA gene by polymerase chain reaction (PCR) method. Antibiotic resistance was evaluated according to Clinical and Laboratory Standards Institute (CLSI). Molecular analyses of penicillin resistance were carried out using specific primers for pbp1a, pbp2b and pbp2x genes. Findings: Of total samples, 50 (80.64%) isolates were confirmed to be S. pneumoniae by PCR assay. Of these isolates, 20 (40%), 10 (20%), and 20 (40%) strains were sensitive, moderately sensitive, and resistant to penicillin, respectively. Out of resistant and moderately sensitive strains, 6 (20%) and 1 (3.33%) strains harbored pbp1a and pbp2x genes, respectively. However, pbp2b was not identified in any samples. Conclusion: Monitoring other kinds of resistance mechanisms is recommended due to the low frequency of pbps genes. Keywords: S. pneumoniae, Penicillin resistance, Penicilline-binding proteins
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