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.

This study aimed to explore the prevalence, antimicrobial resistance levels, and serotype distribution of S. pneumoniae in the Middle East region. We conducted a systematic literature review by searching several databases including PubMed, ISI Web of Science, Scopus, Google scholar through 2000 to 2017 by using the following keywords: “Streptococcus pneumoniae”, “pneumococcus”, “serotype”, “Antibiotic resistance,” and “Middle East “in combination with “OR” and “AND” Boolean Operators within Title/Abstract/Keywords fields. We used a random-effects model to calculate the pooled prevalence and 95% confidence intervals (CIs) for binomial variables. All statistical analyses were done using STATA 12.0 (STATA Corp, College Station, TX). We found 73 articles appropriate, on the word of inclusion and exclusion criteria, for inclusion in this systematic review and meta-analysis. The result revealed that the pooled prevalence of S. pneumoniae carriage was 35% (95% CI: 26-44%). The most frequent pneumococcal serotypes were19, 19F, 6, 23 and 6A/B which were found in 19%,12%, 11%, 10% and 10% of isolates respectively. Pneumococcal resistance reported for azithromycin, cefaclor, clarithromycin, chloramphenicol, erythromycin, and tetracycline were 24%, 37%, 23%, 11%, 26%, and 29% respectively, while vancomycin resistance was not reported. The highest resistant prevalence was reported against co-trimoxazole (Trimethoprim/sulfamethoxazole). For this antibiotic, a pooled resistance prevalence of 43% was identified. The present review demonstrates that the prevalence of S. pneumoniae carriage was high in the Middle East region. Surveillance must be continued in this region to evaluate. The resistance pattern and serotype distribution.

Background Given the significant role of penicillin‐nonsusceptible Streptococcus pneumoniae in inducing severe infectious diseases, identifying serotypes and genotypes that can mediate antimicrobial resistance has become a pillar of treatment strategies. This study aims to determine the correlation between the minimum inhibitory concentration of antimicrobial agents and amino acid mutations in penicillin‐binding proteins. Moreover, molecular serotyping and multiple‐locus variable number tandem repeat analysis typing were first‐ever performed to characterize the invasive penicillin‐nonsusceptible S. pneumoniae isolates in Iran. Methods Of 149 isolates, antimicrobial susceptibility tests were performed against penicillin, ceftriaxone, and cefotaxime by the MIC Test Strip, and sequence analysis of the pbp genes was performed through PCR‐sequencing method. All penicillin‐nonsusceptible S. pneumoniae isolates were serotyped and genotyped by sequential multiplex PCR and multiple‐locus variable‐number tandem repeat analysis, respectively. Results Among pneumococcal isolates, 53 isolates were classified as penicillin‐nonsusceptible S. pneumoniae, of which 38 (71.7%) and 15 (28.3%) were resistant and intermediate to penicillin, respectively. Furthermore, ceftriaxone‐ and cefotaxime‐nonsusceptible pneumococci constituted 33 (62.2%) and 29 cases (54.7%), respectively. Of note, there were 8 and 41 different serotypes and multiple‐locus variable‐number tandem repeat analysis types, respectively. Conclusions Due to the increasing resistance to antimicrobial agents, the most efficient approach to preventing pneumococcal infection mortality as vaccine‐preventable diseases is focusing on wide‐spectrum vaccination. Based on our findings, the 13‐valent pneumococcal conjugate vaccine could considerably reduce the incidence of invasive pneumococcal diseases due to the high rate of serotype coverage.