Clonal spread of β-lactamase-producing amoxicillin–clavulanate-resistant (BLPACR) strains of non-typeable Haemophilus influenzae among young children attending a day care in Japan

Ito, Makoto; Hotomi, Muneki; Maruyama, Yumiko; Hatano, Miyako; Sugimoto, Hisashi; Yoshizaki, Tomokazu; Yamanaka, Noboru

doi:10.1016/j.ijporl.2010.05.008

« Previous Next »International Journal of Pediatric Otorhinolaryngology
Volume 74, Issue 8 , Pages 901-906, August 2010

Clonal spread of β-lactamase-producing amoxicillin–clavulanate-resistant (BLPACR) strains of non-typeable Haemophilus influenzae among young children attending a day care in Japan

Makoto Ito
- Department of Otolaryngology-Head and Neck Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8640, Japan
- Corresponding author. Tel.: +81 72 265 2413; fax: +81 72 234 4265.
Muneki Hotomi
- Department of Otolaryngology-Head and Neck Surgery, Wakayama Prefectural Medical School, Wakayama, Japan
Yumiko Maruyama
- Department of Otolaryngology-Head and Neck Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8640, Japan
- Department of Otolaryngology, Kurobe Civic Hospital, Kurobe, Japan
Miyako Hatano
- Department of Otolaryngology-Head and Neck Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8640, Japan
Hisashi Sugimoto
- Department of Otolaryngology-Head and Neck Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8640, Japan
Tomokazu Yoshizaki
- Department of Otolaryngology-Head and Neck Surgery, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa 920-8640, Japan
Noboru Yamanaka
- Department of Otolaryngology-Head and Neck Surgery, Wakayama Prefectural Medical School, Wakayama, Japan

Received 19 February 2010; received in revised form 30 April 2010; accepted 4 May 2010.

Abstract

Objective

Resistant strains of non-typeable Haemophilus influenzae (NTHi) are one of the principal causes of recurrent acute otitis media (otitis prone), rhinosinusitis, and pneumonia in young children. β-Lactamase-nonproducing ampicillin-resistant (BLNAR) strains are particularly common in Japan, and β-lactamase-producing amoxicillin–clavulanate resistant (BLPACR) strains are now emerging. We investigated the nasopharyngeal carriage status of these resistant strains among children attending a same day care center during a 10-year period.

Methods

From 1999 to 2008, we obtained nasopharyngeal swab specimens from young children attending a same day care center and examined the incidence of resistant strains of NTHi. Antimicrobial resistance of NTHi was identified based on PCR analysis of mutation of the penicillin binding protein (PBP) genes. Pulsed-field gel electrophoresis (PFGE) was performed to examine the clonal relationship of each resistant strain.

Results

The prevalence of resistant strains of NTHi among the children attending this day care has significantly increased during the past 10 years and most of this day care children recently have resistant strains with PBP gene mutations in their nasopharynx. Genetically BLPACR (gBLPACR) strains have rapidly increased since 2007 and PFGE analysis demonstrated that all gBLPACR were clonally identical. This is the first report of apparent clonal dissemination of gBLPACR strains of NTHi occurring in a certain environment such as day care.

Conclusions

The rapidly increasing prevalence of resistant strains, in particular gBLPACR, in this day care center may predict a high incidence of these resistant bacteria from clinical isolates in the near future and potential serious medical problems worldwide.

Abbreviations: AOM, acute otitis media, NTHi, non-typeable Haemophilus influenzae, gBLPACR, genetically β-lactamase-producing amoxicillin–clavulanate-resistant, gBLNAR, genetically β-lactamase-nonproducing ampicillin-resistant, gBLPAR, genetically β-lactamase-producing ampicillin-resistant, gBLNAS, genetically β-lactamase-nonproducing ampicillin-susceptible, Pc^r, penicillin resistance, S. pneumoniae (SP), Streptococcus pneumoniae, PCR, polymerase chain reaction, PBP, penicillin binding protein, RTIs, respiratory tract infections, PFGE, pulsed-field gel electrophoresis