<p>Serotype Distribution and Antibiotic Susceptibility of <em>Streptococcus pneumoniae</em> Isolates in Tehran, Iran: A Surveillance Study</p>

Abstract

Introduction: Encapsulated Streptococcus pneumoniae strains cause high morbidity and mortality, mainly in countries with no pneumococcal conjugate vaccines (PCVs) immunization program. This study investigated the epidemiological changes of S. pneumoniae isolates including serotype distribution and antimicrobial susceptibility in Tehran, Iran. Methods: A total of 80 S. pneumoniae samples were collected from patients admitted to Shariati hospital over two periods. Half of the isolates were collected . The antimicrobial susceptibility testing and PCV-13 serotype coverage of S. pneumoniae isolates were evaluated among patients with invasive and non-invasive infections. Results: The most common serotypes were 23F (17.5%), 14 (16.3%), 3 (16.3%) 19F (12.5%), and 19A (12.5%) in the present study. The vaccine coverage rates of PCV-7, PCV-10 and PCV-13 were 52.6%, 52.6%, and 83.7%, respectively. S. pneumoniae isolates with the serotype of the PCV-13 showed an increasing trend during the study. Nearly half of the S. pneumoniae strains were MDR, while MDR serotype 19A increased (40%) during the study periods. A small minority of isolates (16%) belonged to non-vaccine serotypes, 65% of which were assigned to MDR. In general, the frequency of penicillin resistant and MDR strains were estimated about 27.5% and 51%, respectively. An increase was observed in resistance to erythromycin and co-trimoxazole. Conclusion: The results showed that majority of the circulating serotypes in our study are related to PCV-13 serotypes. The use of conjugate vaccine in the immunization program and surveillance of antimicrobial resistance can be effective in reducing the pneumococcal clinical burden.

Molecular characterization, antibiotic resistance pattern and capsular types of invasive Streptococcus pneumoniae isolated from clinical samples in Tehran, Iran

“…Vaccination has been shown to be effective in reducing the rates of IPD associated with multiple drug resistance [4,5]. But, vaccination against the most common serotypes of S. pneumoniae using PCVs is not still included to the routine immunization program in the Iran and only recommended for high-risk groups [28]. The present study, in addition to others from Iran, shows that the PCV13 could cover the majority of the invasive pneumococcal isolates [19,20,28,29].…”

Profile of Streptococcus pneumoniae Serotypes of Children with Invasive Disease in Tehran, Iran. An Implication for Vaccine Coverage

“…According to a study in Northeast Iran, serotypes 23F, 19F, 19A, 1, 14, and serogroup 6A/B were the most common types among children with suspected meningitis (8). Serotypes 23F, 14, 3, 19, and 19A were reported as the most prevalent in children with invasive and non-invasive pneumococcal infections admitted to Shariati Hospital, Tehran (9). Moreover, in a study on clinical samples obtained from children with an invasive pneumococcal disease from several hospitals in Tehran, 23F, 19F, 19A, and 9V as the most common serotypes (10).…”

Impact of Laboratory Methods and Gene Targets on Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens

“…In most cases, resistance is due to point mutations in atpC, which encodes an ATPase protein subunit (14,17). The differentiation of S. pneumoniae from other related species is essential to choose the appropriate therapeutic strategies, due to the increasing resistance to penicillin and macrolides among pneumococcal and other closely-related species (6,18). We demonstrated that the emergence of optochin-resistant isolates could disrupt the efficiency of conventional tests in diagnosing S. pneumoniae infections.…”