2018 Volume 67 Issue 4 Pages 430-436
During the 1-year period from January to December 2016, 318 strains of Haemophilus influenzae were isolated at our pediatric department from patients aged 29 days to 12 years and 9 months old (median age: 3 years and 0 months). Using these clinical isolates, the capsular type, β-lactamase production, and MICs of 13 antimicrobials (ABPC, PIPC, CTX, CTRX, CDTR, CFTM, AMPC/CVA, PAPM, MEPM, CAM, AZM, TFLX, and LVFX) were investigated. Then, the results were compared with those of three previous studies conducted at the same department (in 1999, 2005, and 2009). The capsular type was nontypable (NT) in 97.8%, type e in 1.9%, and type b in 0.3%. The isolation rate of NT was the highest among the 4 studies, while the isolation rate of type b was the lowest. Resistance (including intermediates) to ABPC, CTX, AMPC/CVA, MEPM, CAM, and AZM was found in 74.8%, 0.9%, 55.7%, 5.3%, 25.8%, and 1.6% of the isolates, respectively. No isolate was resistant to CTRX or LVFX. The ABPC-resistant isolates were BLNAR in 64.5%, BLPAR in 6.6%, and BLPACR in 3.8%, indicating an increase in the BLNAR isolation rate. In Japan, the Hib vaccine became part of the routine vaccination schedule in April 2013, so it is important to carefully monitor the capsular types and antimicrobial susceptibilities of H. influenzae.
