Antibiotic treatment in acute Otitis Media promotes superinfection with resistant Streptococcus pneumoniae carried before initiation of treatment.
Antibiotic-resistant pneumococci are difficult to eradicate from middle ear fluid (MEF) and the nasopharynx (NP). Bacteriologic eradication from the NP and MEF during acute otitis media (AOM) by 3 common antibiotic drugs was prospectively evaluated. In 19 (16%) of 119 MEF culture-positive patients, an organism susceptible to the treatment drug (Haemophilus influenzae, Streptococcus pneumoniae, or both) was isolated from the initial MEF, whereas resistant S. pneumoniae was present in the NP; in 9 (47%) patients, the initial resistant NP organism (identified by serotyping, resistance to the administered drug, and pulsed-field gel electrophoresis) replaced the susceptible MEF organism within only a few days after initiation of treatment. In regions where resistant pneumococci are prevalent, antibiotics may not only fail to eradicate the organisms, but they may often induce MEF superinfection with resistant pneumococci initially carried in the NP. This is an important mechanism by which, in recently treated patients, AOM infections often become refractory to treatment.
Dagan
R
R
Pediatric Infectious Disease Unit, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel. rdagan@bgumail.bgu.ac.il
Leibovitz
E
E
Cheletz
G
G
Leiberman
A
A
Porat
N
N
D000208:Acute Disease; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D002648:Child; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination / Q000627:therapeutic use; D004432:Ear, Middle / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D009305:Nasopharynx / Q000382:microbiology; D010033:Otitis Media / Q000188:drug therapy* / Q000382:microbiology; D011008:Pneumococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D015163:Superinfection / Q000188:drug therapy* / Q000382:microbiology; D013997:Time Factors; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D019980:Amoxicillin-Potassium Clavulanate Combination; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D017963:Azithromycin