title: A pre- and postoperative bacteriological study of chronic suppurative otitis media.
abstract: BACKGROUND
  Although many bacteriological studies on preoperative otorrhea in patients with chronic suppurative otitis media (CSOM) have been performed, there are few studies on postoperative otorrhea. In this study, we analyzed the pathogenic microorganisms, changes in the bacterial species before and after surgery, and the antibiotic sensitivity on preoperative and postoperative cultures.
  
  
  METHODS
  This was a retrospective study of 87 postoperative otorrhea patients who were part of a sample of 1,754 patients with CSOM who underwent tympanomastoidectomy; preoperative and postoperative otorrhea samples were obtained from January 2002 to April 2009. We analyzed patients with postoperative otorrhea divided into two groups: those with early onset (<3 months after surgery, n = 45) and those with late onset (>3 months after surgery, n = 42) otorrhea.
  
  
  RESULTS
  Four species of organisms, methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Pseudomonas, and coagulase-negative Staphylococcus (CNS), showed higher prevalence than others on both the preoperative and postoperative cultures. When we compared the early and late onset otorrhea groups, we found that 'no growth' was significantly higher in the early onset group (n = 19 vs. n = 5), whereas MSSA was significantly higher in the late onset group (n = 1 vs. n = 12). Of the 67 patients with positive preoperative cultures, 15 (22.4%) had the same bacteria after surgery, 34 (50.8%) had other bacteria, 2 (3.0%) had fungi, and 16 (23.8%) showed no growth on postoperative bacteriological testing. MSSA (9%) and MRSA (16.7%) were rarely recultured after surgery, whereas Pseudomonas was recultured frequently (61.5%).
  
  
  CONCLUSIONS
  Unlike MSSA and MRSA, ciprofloxacin-resistant P. aeruginosa (CRP) occasionally causes early onset postoperative otorrhea due to the lack of highly potent antibiotics against this species. The success rate of infection control by surgery and antibiotics was low for CRP.
authors.affiliation: Department of Otolaryngology, College of Medicine, EulJi University, Seoul, Korea.
authors.forename: H J
authors.initials: HJ
authors.lastname: Shim
authors.forename: C H
authors.initials: CH
authors.lastname: Park
authors.forename: M G
authors.initials: MG
authors.lastname: Kim
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: S G
authors.initials: SG
authors.lastname: Yeo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015373:Bacterial Typing Techniques; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010035:Otitis Media, Suppurative / Q000382:microbiology* / Q000601:surgery*; D011184:Postoperative Period; D057234:Preoperative Period; D011549:Pseudomonas / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D011552:Pseudomonas Infections / Q000382:microbiology*; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D055815:Young Adult