The prevalence and antimicrobial susceptibility of circulating S. pneumoniae serotypes in adult population in Russia (epidemiological study «SPECTRUM»)

Objective. To estimate prevalence and antimicrobial susceptibility of circulated S. pneumoniae serotypes in adult population in different regions of the Russian Federation. Materials and Methods. A total of 500 isolates of S. pneumoniae obtained from patients with invasive pneumococcal disease (IPD), community-acquired pneumonia (CAP), sinusitis/acute otitis media (AOM) and healthy carriers from 29 centers were included in the study from 01 June 2019 to 15 January 2020. Re-identification, typing using real-time PCR with 27 primer pairs and antimicrobial susceptibility testing were performed in the central laboratory by standardized methods. Results. Among 50 isolates from patients with IPD, the following serotypes were detected: 3 (20.0%), 23F (10.0%), 6ABCD (8.0%), 19F (6.0%), 12ABF, 4, 7AF, 8, 9NL, 9VA, 15B (4.0% each), 1, 10A, 11AD, 14, 15AF, 18ABCF, 22AF, 33F/33A/37 (2.0% each). PCV-13 and PPV-23 covered 62.0% and 86.0% of those serotypes, respectively. Among 357 isolates from patients with CAP, the following serotypes were detected: 19F (12.3%), 6ABCD (11.5%), 3 (10.1%), 23F (5.9%), 14 (5.3%), 22AF (5.0%), 11AD (4.8%), 9NL (3.4%), 15AF (2.8%), 9VA (2.2%), 18ABCF (2.0%), 19A (1.7%), 12ABF (1.4%), 17F (0.8%), 16, 33F/33A/37, 7AF and 8 (0.6% each), 10A and 4 (0,3% each); serotypes were not specified due to the PCR typing protocol limitations for 106 (29.8%) isolates. PCV-13 and PPV-23 covered 51.9% and 68.7% of those serotypes, respectively. In patients with sinusitis/AOM (n = 48), serotypes were: 19F (18.8%), 6ABCD (16.7%), 23F (12.5%), 3 (12.5%), 18ABCF (6.3%), 11AD (4.2%), 14 (4.2%), 22AF (4.2%), 15AF, 4, 9VA (2.1% each). PCV-13 and PPV-23 covered 75.0% and 83.3% of those serotypes, respectively. In healthy nasopharyngeal carriers (n = 45), the following serotypes were detected: 19F (24.4%), 3 (17.8%), 6ABCD (17.8%), 11AD (13.3%), 23F (8.9%), 22AF (6.7%), 14 and 15AF (2.2% each). PCV-13 and PPV-23 covered 71.1% and 91.1% of those serotypes, respectively. Serotypes 14, 19F, and 19A were frequently resistant to three antibiotics – penicillin, erythromycin, and tetracycline. Resistance to respiratory quinolones was very low (0.7%) and detected among serotypes 14 and 9NL only. The majority of non-vaccine serotypes did not have substantial antimicrobial resistance problems. Conclusions. Despite the relatively low number of isolates in all but CAP group and limitations of PCR typing protocol, results of our study support the use of pneumococcal vaccines (PPV-23 and PCV-13) in Russian adult population, with some advantages of PPV-23 over PCV-13.