High Prevalence of Group III-Like Mutations Among BLPACR and First Report of Haemophilus influenzae ST95 Isolated from Blood in China

We aimed to evaluate antibiotic resistance and molecular epidemiological characteristics of non-invasive ( ) from pneumonia patients and analyze the whole genome of one invasive isolated from blood in pediatric patients. Antibiotic susceptibility was tested using the turbidimetric method. β-lactamase-producing and serotyping genes were evaluated via multiplex polymerase chain reaction (PCR), and was amplified using high-fidelity PCR. Lastly, whole genome sequencing (WGS) was conducted using Illumina HiSeq and PacBio sequencing technology. We observed that the ampicillin (AMP) and amoxicillin/clavulanate (AMC) resistance rates of non-invasive were as high as 99.06% (after adjustment) and 49.53%, respectively. The β-lactamase gene of 106 AMP-resistant strains was . Group III-like mutation accounted for 71.15% of β-lactamase-positive, AMC-resistant (BLPACR) strain mutants. The novel Asn-526→His mutation was present in one β-lactamase-negative AMP-susceptible (BLNAS) strain. Non-invasive strains all belonged to non-typeable (NTHi). In contrast, the invasive 108 isolated from blood in China belonged to type b (Hib). It belonged to sequence typing ST95 and exhibited sensitivity to all 11 antibiotics. Three prophages were identified, and the b loci of the strain 108 revealed regions I-III exist in duplicate; however, complete deletion of IS1016 was only present in one of the copies. Non-invasive NTHi with β-lactamase-positive was highly prevalent. Notably, group III-like mutations had increased prevalence among BLPACR strains. belonging to Hib and ST95 was first reported to cause sepsis in China.