Characterization of Serotypes and Molecular Drug Resistance Patterns of Haemophilus influenzae in Kunming Children

The present study aimed to determine the capsular serotype distribution and antimicrobial drug resistance patterns of Haemophilus influenzae from children in the Kunming region of China. This information could guide policymakers in clinical treatment. In the present study, H. influenzae isolates were tested for their serotypes, antimicrobial susceptibility pattern, and presence of beta-lactamases. One-hundred forty-eight H. influenzae strains isolated from children 0-2 years old were investigated for capsular types by glass slide agglutination and molecular methods, and biotyped by the biochemical reactions. The drug resistance-encoding genes TEM-1, ROB-1, and the ftsI gene mutations PBP3-3, and PBP3-BLN were detected with real-time quantitative polymerase chain reaction (qPCR). The prevalence of beta-lactamase-producing strains (60.3%) was significantly higher (p < 0.05) than non-enzyme-producing strains. beta-Lactamase-producing strains were multidrug resistant to various antibiotics such as ampicillin, tetra-cycline, sulfamethoxazole/trimethoprim, chloramphenicol, cefuroxime, and cefaclor. Among beta-lactamase-producing strains, the detection rates of the TEM-1, PBP3-BLN, PBP3-s, and ROB-1 were 54.1%, 18.9%, 11.8%, and 6.9%, respectively. The biotyping results show that most H. influenzae strains were of type II and III. Non-typeable H. influenzae (NTHi) accounted for 89.3% of the strains. NTHi strains were the most prevalent in this region; most belonged to biological types II and III. beta-Lactamase-positive ampicillin-resistant (BLPAR) strains were prevalent among H. influenzae isolates in this region.

Automated summary

The aim of this study was to determine the distribution of capsular serotypes and antimicrobial drug resistance patterns of Haemophilus influenzae in the Kunming region of China. The results showed that the majority of the isolates were non-typeable H. influenzae, with high prevalence of beta-lactamase-producing strains that were resistant to multiple antibiotics.