title: Clinical characteristics of pneumonia caused by penicillin resistant and sensitive Streptococcus pneumoniae in Japan.
abstract: BACKGROUND
  S. pneumoniae is the leading cause of morbidity and mortality worldwide. P-lactam antibiotics were very effective against S. pneumoniae, however resistance to this class of antibiotic has become an increasing problem.
  
  
  OBJECTIVE
  To assess the clinical differences between penicillin-sensitive and penicillin-resistant pneumococcal pneumonia.
  
  
  METHODS
  The medical records of 306 patients with pneumococcal pneumonia who visited Nagasaki University Hospital or affiliated institutions between January 1997 and December 2001 were retrospectively reviewed. The Pneumonia Severity Index (PSI), sensitivity of S. pneumoniae, antibiotic choices and information on clinical outcome were evaluated.
  
  
  RESULTS
  Penicillin sensitive and resistant organisms were responsible for 177 (57.7%) and 129 (42.0%) cases of pneumonia, respectively. The median age of patients was 65.5 years, and 72.3% (222) were males. There were no significant differences in the resistance rate between elderly (>65 years) and young patients. The median PSI score was 76. No significant association was observed between the severity of illness and sensitivities of S. pneumoniae. Previous use of beta-lactams in the last 3 months and chronic obstructive pulmonary disease were associated with penicillin resistance. The failure rate of first line antibiotics was significantly higher in the resistant group (22.5%) than in the sensitive group (9.0%). Four of 306 patients died (mortality, 1.3%).
  
  
  CONCLUSIONS
  There were no significant differences clinically between the penicillin-sensitive and penicillin-resistant groups. The failure rate of first line antibiotics was higher in the resistant than in the sensitive group. Thus, the selection of antimicrobial agents should be carefully considered in the context of the patient's risk factors.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University Graduate School of Medical Sciences, Nagasaki.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Yanagihara
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Otsu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ohno
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Higashiyama
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hirakata
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tomono
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kadota
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tashiro
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D010403:Penicillin Resistance; D010406:Penicillins / Q000627:therapeutic use*; D011018:Pneumonia, Pneumococcal / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins