title: Antibiotic resistance in sputum isolates of Streptococcus pneumoniae in chronic obstructive pulmonary disease is related to antibiotic exposure.
abstract: Streptococcus pneumoniae (S. pneumoniae) is recovered from sputum of patients with chronic obstructive pulmonary disease (COPD) during stable disease and exacerbations. In patients with community acquired pneumonia, antibiotic exposure in the prior 3-6 months is associated with recovery of antibiotic resistant isolates of S. pneumoniae. Whether the same relationship is seen in COPD is not known. From April 1994 to June 2004, 127 adults with COPD were enrolled in a prospective longitudinal study. Sputum isolates of S. pneumoniae were characterized with susceptibility testing and pulsed-field gel electrophoresis (PFGE). The relationship between antibiotic use in the previous 3 and 6 months with either new acquisition of a resistant pneumococcal isolate or development of resistance (4-fold increase in MIC) in a pre-existing colonizing pneumococcal strain was determined. A total of 194 pneumococcal isolates were recovered from 38 patients. Among 71 newly acquired and 4 resistance-emergent strains analyzed further, rates of resistance to penicillin (MIC ≥2), erythromycin (MIC ≥1), tetracycline (MIC ≥8) and trimethoprim/sulfamethoxazole (MIC ≥4) were 8%, 24%, 17% and 16% respectively. Flouroquinolone resistance was not seen. Among strains isolated from patients exposed to a macrolide within 6 months, 53.6% displayed erythromycin resistance vs. 14% of strains without such exposure (p = 0.00085). Similar associations were not seen for other antibiotics. Macrolide use in the previous 6 months is associated with macrolide resistance in sputum isolates of S. pneumoniae. Recent antibiotic exposure may help in determining appropriate antibiotic treatment in these patients.
authors.affiliation: Eastern Virginia Medical School, Norfolk, VA, USA. desaihd@evms.edu
authors.forename: Himanshu
authors.initials: H
authors.lastname: Desai
authors.forename: Sandra
authors.initials: S
authors.lastname: Richter
authors.forename: Gary
authors.initials: G
authors.lastname: Doern
authors.forename: Kris
authors.initials: K
authors.lastname: Heilmann
authors.forename: Cassie
authors.initials: C
authors.lastname: Dohrn
authors.forename: Antoinette
authors.initials: A
authors.lastname: Johnson
authors.forename: Aimee
authors.initials: A
authors.lastname: Brauer
authors.forename: Timothy
authors.initials: T
authors.lastname: Murphy
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sethi
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011008:Pneumococcal Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D013183:Sputum / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents