Predominance of serogroup 19 CC320/271 among penicillin-non-susceptible Streptococcus pneumoniae isolates after the introduction of the PCV7 vaccine in several regions of Japan.

Predominance of serogroup 19 CC320/271 among penicillin-non-susceptible Streptococcus pneumoniae isolates after the introduction of the PCV7 vaccine in several regions of Japan. Jpn J Infect Dis. 2017 Oct 31;: Authors: Oodate M, Kimura K, Banno H, Yokoyama S, Jin W, Wachino JI, Hasegawa Y, Arakawa Y Abstract Multidrug-resistant Streptococcus pneumoniae serogroup 19, including serotypes 19A and 19F, associated with clonal complex 320/271 (CC320/271), was previously shown to be predominant in many countries after the introduction of a seven-valent pneumococcal conjugate vaccine (PCV7). However, in Japan there has been no epidemiological research focused on penicillin-non-susceptible isolates after this event. Thus, we aimed to characterize penicillin-non-susceptible S. pneumoniae (PNSSP; penicillin minimum inhibitory concentration (MIC) ≥ 4.0 µg/ml) after the introduction of PCV7 in Japan. From throughout Japan, we collected 1057 pneumococcal isolates from 2010 to 2014. We then evaluated MICs and performed serotyping, multilocus sequence typing, and sequencing of penicillin binding protein (PBP) genes of 51 isolates (penicillin MIC ≥ 2.0 µg/ml). Twenty-three isolates (2.2%) showed penicillin-non-susceptibility (penicillin MIC ≥ 4.0 µg/ml). Serotypes 19F (14 isolates, 60.9%) and 23F (4 isolates, 17.4%), which are covered by the vaccine, were predominant among PNSSP strains. Only three isolates were of the non-vaccine serotype 1...
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research