Decline in antibiotic resistance and changes in the serotype distribution of Streptococcus pneumoniae isolates from children with acute otitis media; a 2001–2011 survey by the French Pneumococcal Network

Abstract

Streptococcus pneumoniae is an important cause of acute otitis media (AOM). The aim of this study was to evaluate trends in antibiotic resistance and circulating serotypes of pneumococci isolated from middle ear fluid of French children with AOM during the period 2001-2011, before and after the introduction of the PCV-7 (2003) and PCV-13 (2010) vaccines. Between 2001 and 2011 the French pneumococcal surveillance network analysed the antibiotic susceptibility of 6683 S. pneumoniae isolated from children with AOM, of which 1569 were serotyped. We observed a significant overall increase in antibiotic susceptibility. Respective resistance (I+R) rates in 2001 and 2011 were 76.9% and 57.3% for penicillin, 43.0% and 29.8% for amoxicillin, and 28.6% and 13.0% for cefotaxime. We also found a marked reduction in vaccine serotypes after PCV-7 implementation, from 63.0% in 2001 to 13.2% in 2011, while the incidence of the additional six serotypes included in PCV-13 increased during the same period, with a particularly high proportion of 19A isolates. The proportion of some non-PCV-13 serotypes also increased between 2001 and 2011, especially 15A and 23A. Before PCV-7 implementation, most (70.8%) penicillin non-susceptible pneumococci belonged to PCV-7 serotypes, whereas in 2011, 56.8% of penicillin non-susceptible pneumococci belonged to serotype 19A. Between 2001 and 2011, antibiotic resistance among pneumococci responsible for AOM in France fell markedly, and PCV-7 serotypes were replaced by non-PCV-7 serotypes, especially 19A. We are continuing to assess the impact of PCV-13, introduced in France in 2010, on pneumococcal serotype circulation and antibiotic resistance.

The multifaceted impact of pneumococcal conjugate vaccine implementation in children in France between 2001 to 2014

“…Another recent French study evaluated the trends in antibiotic resistance and serotype distribution of pneumococci isolated from MEF in children with AOM from 2001 to 2011. 36 The authors reported a marked reduction in infection with vaccine serotypes after PCV7 implementation, from 63.0% in 2001 to 13.2% in 2011, with increased incidence of infection with the additional 6 serotypes included in PCV13 during the same period, with a particularly high proportion of 19A isolates. 36 After PCV13 implementation, H. influenzae was the most frequent otopathogen isolated and accounted for 75.9% of positive MEF samples.…”

“…22,26,36,39,40 Indeed, we previously demonstrated the strong impact of the PCV7 implementation, combined with reduced antibiotic use, on the carriage of penicillin non-susceptible pneumococci in children with AOM. 22 After PCV13 implementation, because selective pressure continues to occur with excessive antibiotic consumption in France, some non-vaccine serotypes are frequently resistant.…”

“…29 Middle ear fluid (MEF) was obtained by tympanocentesis and/or by sampling spontaneous discharge according to recommended clinical practice guidelines. 29,[33][34][35][36] These studies performed before and after PCV implementation allow for analyzing the epidemiology of pathogens involved in AOM treatment failure. Figure 7 presents the pathogens recovered by period considered in these different studies.…”

“…28,29,[33][34][35][36] Antibiotic treatment failure was defined as the persistence of AOM symptoms after at least 48 hours of antibiotics or their recurrence within 4 d after the end of treatment. 29 Middle ear fluid (MEF) was obtained by tympanocentesis and/or by sampling spontaneous discharge according to recommended clinical practice guidelines.…”

Directed vaccination against pneumococcal disease

“…Notably, before the 1990s, most S. pneumoniae strains demonstrated universal sensitivity to penicillin (12). Today, however, penicillin resistance varies from 5-60% in various parts of the world (13,14). Of particular concern is the increase in multidrugresistant S. pneumoniae strains demonstrating resistance to three or more drug classes (15)(16)(17)(18), which creates substantial concerns about both the efficacy of current antibiotic regimens and the continual development of resistance.…”