Impact of Antimicrobial Therapy on Nasopharyngeal Carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis in Children with Respiratory Tract Infections

• Published in: Clinical infectious diseases 2000-08, Vol.31 (2), p.477-481
• Main Authors: Varon, Emmanuelle, Levy, Corinne, De La Rocque, France, Boucherat, Michel, Deforche, Dominique, Podglajen, Isabelle, Navel, Michel, Cohen, Robert
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antibacterial agents; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobials; Biological and medical sciences; Carrier State - drug therapy; Carrier State - microbiology; Children; Culture Media; Dosage; Electrophoresis, Gel, Pulsed-Field; Gram-Negative Bacterial Infections - drug therapy; Gram-Negative Bacterial Infections - microbiology; Haemophilus Infections - drug therapy; Haemophilus Infections - microbiology; Haemophilus influenzae; Haemophilus influenzae - drug effects; Haemophilus influenzae - genetics; Haemophilus influenzae - isolation & purification; Major Articles; Medical sciences; Microbial Sensitivity Tests; Moraxella (Branhamella) catarrhalis - drug effects; Moraxella (Branhamella) catarrhalis - genetics; Moraxella (Branhamella) catarrhalis - isolation & purification; Nasopharynx - drug effects; Nasopharynx - microbiology; Otitis media; Pathogens; Penicillin; Pharmacology. Drug treatments; Pneumococcal Infections - drug therapy; Pneumococcal Infections - microbiology; Prospective Studies; Random Amplified Polymorphic DNA Technique; Respiratory Tract Infections - drug therapy; Respiratory Tract Infections - microbiology; Siblings; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - isolation & purification
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1086/313981

We conducted a multicenter prospective study to document changes in nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis during antibiotic therapy. A cohort of 629 children with respiratory tract infections underwent nasopharyngeal sampling before and after antibiotic treatment. Susceptibility testing, serotyping, arbitrarily primed polymerase chain reaction, and pulsed-field gel electrophoresis were used to compare pretreatment and posttreatment strains of S. pneumoniae. A significant decrease in carriage of all 3 species (especially S. pneumoniae and B. catarrhalis) was recorded. The increase in the proportion of penicillin-resistant pneumococci (PRP; 66% vs. 44%) was due to the decreased carriage of penicillin-susceptible pneumococci (71 of 629 vs. 176 of 629). The risk of PRP carriage in a given child did not increase. None of the children was found to harbor genetically related strains with increased minimum inhibitory concentrations. Given the multiple resistance of PRP, β-lactam antibiotic therapy also increased the incidence of macrolide-resistant strains, whereas macrolides selected both macrolide- and penicillin-resistant strains.