Impact of the pneumococcal conjugate vaccine on serotype distribution of adult non-invasive Streptococcus pneumoniae isolates in Tokai region, Japan, 2008-2016.

The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease and changed serotype distribution in Japan. In November 2013, PCV7 was replaced by the 13-valent pneumococcal conjugate vaccine (PCV13). We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from adult patients. A total of 504 pneumococcal isolates were collected during 4 periods between 2008 and 2016 (Period 1; between June 2008 and April 2009, Period 2; between September 2010 and March 2011, Period 3; between October 2011 and March 2012, Period 4; between August 2015 and January 2016). The coverage of PCV7 and PCV13 significantly decreased from 38.6% and 60.5% in Period 1 to 6.6% and 31.1% in Period 4. This change was mainly due to a large decrease in the frequency of serotype 19F, 6B, and 14. Serotype 3 was the most frequently isolated, and gradually increased. Additionally, non-PCV13 serotypes 11A, 33F, and 35B significantly increased. Most of the PCV7 serotypes 19F, 23F, 6B, and 14 had mutations of penicillin-binding protein genes and macrolide resistance genes, and these serotypes showed low susceptibilities to cefdinir and clarithromycin. On the other hand, a significant change in susceptibility to various antimicrobial agents was not observed throughout the study period, except for decreased susceptibility to carbapenems. Continuous surveillance studies of pneumococcal serotype changes and drug susceptibility are necessary in future.

Impact of the pneumococcal conjugate vaccine on serotype distribution and susceptibility trends of pediatric non-invasive Streptococcus pneumoniae isolates in Tokai, Japan over a 5-year period.

Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease (IPD) and changed serotype distribution in Japan. We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from pediatric patients. A total of 564 pneumococcal isolates were collected over a 5-year period between 2008 and 2012. The coverage of PCV7 significantly decreased throughout the study period, from 49.3% in period 1 (between June 2008 and April 2009) to 23.4% in period 4 (between October 2011 and March 2012). This change was mainly due to a large decrease in the frequency of 19F (from 20.6% to 9.9%) and 6B (from 10.3% to 2.7%) and an increase in serotype 3 (from 5.1% to 13.5%) and serogroup 15 (from 4.4% to 9.0%). According to serotype replacement, the susceptible ratios of S. pneumoniae to ß-lactams increased slightly while macrolide resistance remained high. The high frequency of macrolide-resistant pneumococcal isolates may continue because of the high frequency of erm(B) in replace serotypes such as serotype 3 and serogroup 15. The continuous surveillance study is essential following the introduction of a second generation 13-valent pneumococcal conjugate vaccine (PCV13).

Therapeutic effects of garenoxacin in murine experimental secondary pneumonia by Streptococcus pneumoniae after influenza virus infection.

In a pneumococcal pneumonia murine model following influenza virus infection, garenoxacin was more effective than other fluoroquinolones and demonstrated high levels of bacterial eradication in the lung, low mortality, and potent histopathological improvements. Garenoxacin could potentially be used for the treatment of secondary pneumococcal pneumonia following influenza.

[Sensitivity surveillance of Streptococcus pneumoniae isolates for several antibacterial agents in Gifu and Aichi prefecture (2008-2009)].

We investigated the susceptibility to antibacterials, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes against 377 strains of Streptococcus pneumoniae isolated from medical facilities in Gifu and Aichi prefectures between June 2008 and April 2009. These results were compared with those against 160 strains of S. pneumoniae isolated in 2004. Referring to CLSI (M100-S17), the overall incidence of penicillin-susceptible (PSSP), penicillin-intermediate (PISP) and penicillin-resistant (PRSP) S. pneumoniae was 143 (38%), 185 (49%) and 49 (13%) strains, respectively. PISP and PRSP were isolated higher in the material of nasal cavity and throat, and PRSP was isolated higher in the area of Chuno district. The number of gPSSP with 3 normal PBP genes, gPISP with 1 or 2 normal PBP genes and gPRSP with 3 abnormal genes was 23 (6.1%), 173 (46%) and 181 (48%) strains, respectively. The isolates with no macrolide-resistant gene, only mefA, only ermB, and both mefA and ermB were 28 (7.4%), 138 (37%), 166 (44%) and 45 (12%). The prevalent pneumococcal serotypes were type 19 (92 strains; 24%), following by type 23 (60 strains; 16%) and type 6 (56 strains; 15%). The 80% of pneumococcal serotypes of PRSP were serotype 19 and 6. The MIC90 of each antibacterial was as follows; 0.1 microg/mL for imipenem, panipenem and garenoxacin, 0.2 microg/mL for moxifloxacin, 0.39 microg/mL for meropenem and tosufloxacin, 0.78 microg/ mL for amoxicillin, clavulanic acid/amoxicillin, cefditoren and cefcapene, 1.56 microg/mL for benzylpenicillin, piperacillin, cefteram and levofloxacin, 3.13 microg/mL for cefotiam, flomoxef and pazufloxacin, 6.25 microg/mL for cefdinir, 12.5 microg/mL for norfloxacin and minocycline, > 100 microg/mL for clarithromycin, and these MIC90s were about the same as those in 2004.

Tratamiento del absceso pulmonar / Pulmonary abscess treatment

Con el objetivo de evaluar la efectividad del tratamiento médico del absceso pulmonar se realizó un estudio retrospectivo de la historia clínica de 28 pacientes ingresados en el Hospital General del Sur Dr. Pedro Iturbe con diagnóstico del padecimiento durante el período comprendido entre enero de 1994 y diciembre de 1998. Se administró como tratamiento empírico a la combinación de penicilina sódica a dosis de dos millones de U vía EV cada cuatro horas y amikacina 500 mg vía EV cada 12 horas. Los pacientes fueron clasificados en agudos y crónicos de acuerdo al tiempo de evolución. Se utilizó broncoscopía flexible como método auxiliar en el drenaje de pacientes con absceso crónico y en los que la terapéutica inicial había fallado: se llevó a cabo la cirugía sólo en caso de fracaso del tratamiento médico. El sexo masculino predominó sobre el femenino con una proporción de 3:1. El grupo etario más afectado fue el comprendido entre 35 a 45 años. El hallazgo radiológico más frecuente fue la presencia de una imagen excavada con nivel hidroáereo> de 4 cm de diámetro. El germen más frecuente en los cultivos fue klebsiella penumoniae (28.57 por ciento). La localización pulmonar predominó en el lóbulo superior derecho (42,86 por ciento). Las enfermedades intercurrentes más frecuentes fueron: la enfermedad periodontal (25 por ciento) y epilepsia (25 por ciento). El tratamiento médico sin aspiración fue exitoso en seis pacientes (21,44 por ciento) en fase aguda y en nueve pacientes con aspiración (32,14 por ciento). En los pacientes crónicos eltratamiento médico sin aspiración fue exitoso en cuatro pacientes (14,28 por ciento), cinco (17,86 por ciento) con broncoscopía y cuatro (14,28 por ciento) se resolvieron con cirugía. La combinación de penicilina con amikacina fue la más efectiva; su eficacia aumenta cuando se acompaña de broncoscopía aspirativa, ésta debe ser realizada cuando se presenta lenta resolución, reservando la cirugía para los casos crónicos sin respuesta favorable