TY - JOUR AU - Tanaka, Emi AU - Hirai, Yuji AU - Wajima, Takeaki AU - Ishida, Yu AU - Kawamura, Yoshiaki AU - Nakaminami, Hidemasa T1 - High-Level Quinolone-Resistant Haemophilus haemolyticus in Pediatric Patient with No History of Quinolone Exposure T2 - Emerging Infectious Disease journal PY - 2022 VL - 28 IS - 1 SP - 104 SN - 1080-6059 AB - The prevalence of antimicrobial resistance among Haemophilus spp. is a critical concern, but high-level quinolone-resistant strains had not been isolated from children. We isolated high-level quinolone-resistant H. haemolyticus from the suction sputum of a 9-year-old patient. The patient had received home medical care with mechanical ventilation for 2 years and had not been exposed to any quinolones for >3 years. The H. haemolyticus strain we isolated, 2019-19, shared biochemical features with H. influenzae. However, whole-genome analysis found this strain was closer to H. haemolyticus. Phylogenetic and mass spectrometry analyses indicated that strain 2019-19 was in the same cluster as H. haemolyticus. Comparison of quinolone resistance–determining regions showed strain 2019-19 possessed various amino acid substitutions, including those associated with quinolone resistance. This report highlights the existence of high-level quinolone-resistant Haemophilus species that have been isolated from both adults and children. KW - antimicrobial resistance KW - quinolone resistance KW - bacteria KW - Haemophilus spp. KW - Haemophilus haemolyticus KW - Haemophilus influenzae KW - quinolone KW - respiratory infections DO - 10.3201/eid2801.210248 UR - https://wwwnc.cdc.gov/eid/article/28/1/21-0248_article ER - End of Reference