Multicenter study of serotype distribution of Streptococcus pneumoniae nasopharyngeal isolates from healthy children in the Russian Federation after introduction of PCV13 into the National Vaccination Calendar.

Russia introduced PCV13 in 2014. We studied the serotype composition of S. pneumoniae isolated from the nasopharynx of healthy children younger than 6 years in St. Petersburg, Smolensk, Perm, Krasnoyarsk, Khanty-Mansiysk and Khabarovsk, between 2016 and 2018. 2.4% of children had completed a 3-dose course of PCV13, while 25.6% had received 1 or 2 doses. Pneumococcal DNA detection by PCR demonstrated S. pneumoniae in 37.2% of samples with regional variation between sites (27.3 to 56.9%). There was little difference between vaccinated, partially vaccinated and un-vaccinated children. Children who had received at least 1 dose of PCV13 had lower carriage rates of vaccine serotypes than their unvaccinated peers (49.9 vs. 61.4%; p < 0.001). Children who had received at least 1 dose of PCV13 showed increased carriage rates of non-vaccine serotypes (50 vs 38.6%; P < 0.001). Especially serogroup 15AF was more prevalent among fully immunized children than among their peers (12.5 vs 2.7%; P < 0.05).

Molecular characterization of Streptococcus pneumoniae, particularly serotype19A/ST320, which emerged in Krasnoyarsk, Russia.

Streptococcus pneumoniae, a common human pathogen, colonizes the nasopharynx and causes diseases including acute otitis media (AOM). Herein, pneumococcal serotype distributions in children before and after PCV7 vaccination and in patients with pneumococcal disease in Siberian Russia (Krasnoyarsk) are reported. Analyses included antimicrobial susceptibility testing, sequence typing (ST), pulsed field gel electrophoresis, virulence-related surface protein gene (VSG) typing with novel primers and structural analysis by scanning electron microscopy. In healthy children (HC) prior to administration of PCV7, drug-susceptible serotype23F/ST1500 was a major pneumococcal genotype. In the PCV7 trial, multidrug-resistant serotype19A/ST320 emerged in vaccinees after PCV7, exhibiting a PCV7-induced serotype replacement. Multidrug-resistant serotype19A/ST320 was evident in patients with AOM. Community-acquired pneumonia (CAP) isolates showed genetic similarities to the AOM (ST320) genotype, constituting a common non-invasive AOM-CAP group. In contrast, meningitis isolates were more divergent. Overall, 25 ST types were identified; five (20%) of which were Krasnoyarsk-native. Regarding VSGs, PI-1 (rlrA/rrgB), PI-2 (pitA/B), psrP and cbpA were present at 54.3%, 38.6%, 48.6%, and 95.7%, respectively, with two major VSG content types, PI-1- /PI-2- /psrP+ /cbpA+ and PI-1+ /PI-2+ /psrP- /cbpA+ , being found for HC and non-invasive diseases, respectively. A major clone of serotype19A/ST320 (PI-1+ /PI-2+ ) produced the longest pneumococcal wire (pilus) structures in colonies. ST1016 (PI-1- /PI-2- ) in HC had HEp-2 cell-adherent pili. These results suggest that serotype19A/ST320 and related genotypes, with the VSG content type PI-1+ /PI-2+ /psrP- /cbpA+ , emerged in vaccinees after PCV7 in Siberia, accompanying diseases in non-vaccinated children, and that some genotypes (serotypes19A/ST320 and 18/ST1016) produced novel pneumococcal structures, predicting their roles in colony formation and adherence.

Monitoring Reactions on Solid Phases with Raman Spectroscopy.

The benefits of Raman spectroscopy were shown for the on-bead monitoring of diverse reactions. Raman spectroscopy was used for the development of new procedures on established linker systems, the real-time observation of several reactions on solid phases and the estimation of the reaction time for a new cleavage strategy. Selected conversions on solid phases, such as the on-bead conversion of functional groups and the attachment of novel building blocks, were demonstrated. Raman spectra were obtained after isolation and purification of the solid supports, but they were also measured directly in the reaction vessels. Even the detection of Raman-active functional groups in swollen polymer resins and in reaction mixtures was demonstrated, and allows real-time observation of the progress of diverse reactions on solid supports.

Synthesis of Diaziridines and Diazirines via Resin-Bound Sulfonyl Oximes.

Diazirines are one of the most prominent functionalities in labeling experiments in vivo and in vitro because they allow photochemical generation of carbenes. The strategy presented herein describes the formation of diaziridines, being essential precursors in diazirine syntheses, using solid-supported procedures with immobilized sulfonyl oximes. The solid-supported building blocks have been shown to be valuable intermediates for CuAAC and amidation reactions, offering the possibility to build complex compounds with diverse functionalities.