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Volume 51, Number 3, June 2018

Acute otitis media caused by Streptococcus pneumoniae serotype 19A ST320 clone: epidemiological and clinical characteristics
 


Hsin Chi, Nan-Chang Chiu, Fu-Yuan Huang, Chyong-Hsin Hsu, Kuo-sheng Lee, Li-Min Huang, Yu-Chia Hsieh


 

Corresponding author:

Affiliations
Department of Pediatrics, Chang Gung Children’s Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan
Correspondence
Corresponding author. Department of Pediatrics, Chang Gung Children’s Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, 5 Fu-Hsin Street, Kwei-Shan Hsiang, Taoyuan County 333, Taiwan. 



 

Background and purpose: 

Streptococcus pneumoniae serotype 19A ST320, a highly multiresistant and virulent clone, has emerged as a common pathogen causing acute otitis media (AOM) in children. 



 

Methods:

Patients aged 0–18 years with AOM who presented at Mackay Memorial Hospital, Taipei, Taiwan were prospectively enrolled between December 1, 2009, and November 30, 2012. For each patient, a specimen of middle-ear fluid was obtained and cultured. S. pneumoniae isolates were tested by serotyping, antibiotic-resistance profiling, and multilocus sequence typing. Demographic characteristics and clinical history of patients with pneumococcal AOM were recorded. 



 

Results:

Pneumococcal AOM was observed in 108 (24.8%) of 436 episodes. One hundred and four isolates of S. pneumoniae were available for study. The most common serotypes were 19A (67 isolates, 64.4%), followed by 19F (16 isolates, 15.4%), and 3 (7 isolates, 6.7%). Among the 85 sequence-typed isolates, Serotype 19A ST320 (50, 58.8%) was the most frequent. Children with AOM caused by Serotype 19A ST320 were younger (33.9 ± 21.4 months vs. 46.7 ± 35.9 months, p = 0.04) and had a higher rate of spontaneous rupture of the tympanic membrane (64.0% vs. 40%, p = 0.05) than those caused by isolates of other sequence types. Serotype 19A ST320 caused 90% of AOM episodes in children aged ≤ 12 months and had had higher resistance rates to penicillin according to meningeal breakpoints (p = 0.011), amoxicillin (p < 0.001) and trimethoprim/sulfamethoxazol (p < 0.001). 



 

Conclusion:

It is better to use pneumococcal conjugate vaccine effective against Serotype 19A in early infancy to prevent the first and subsequent episodes of AOM in children in Taiwan. 



 

Key words:

acute otitis media, Serotype 19A, Streptococcus pneumoniae