Abstract：
Haemophilus influenzae, a causative agent of severe invasive infections such as meningitis, sepsis and pneumonia, is classified into encapsulated or typeable (represented by serotypes A to F) and non-typeable varieties (NTHi) by the presence or absence of the polysaccharide capsule. Invasive disease caused by H. influenzae type B (HIB) can be prevented through vaccination which remains the main disease control intervention in many countries. This study examined the genomic diversity of circulating H. influenzae strains associated with invasive disease in New South Wales, Australia, before and during the COVID-19 pandemic. Ninety-six isolates representing 95 cases of invasive H. influenzae infections (iHi) diagnosed between January 2017 and September 2022 were typed and characterised using whole genome sequencing. These cases were caused by serotypes A (n=24), B (n=35), E (n=3), F (n=2) and NTHi (n=32). There was an apparent decline in the number of iHi infections during the COVID-19 pandemic, with a corresponding increase in the proportion of iHi cases caused by serotype A (HIA), which returned to pre-pandemic levels in 2022. Fifteen isolates associated with HIB or non-typeable iHi were resistant to β-lactams due to a PBP3 mutation or carriage of blaTEM-1. Further, capsular gene duplication was observed in HIB isolates but was not found in HIA. These findings provide important baseline genomic data for ongoing iHi surveillance and control.
摘要：
流感嗜血杆菌,严重侵袭性感染的病原体，如脑膜炎，脓毒症和肺炎,根据多糖胶囊的存在或不存在,将其分类为包封的或可分型的(由血清型A至F表示)和不可分型的品种(NTHi)。由B型流感嗜血杆菌（HIB）引起的侵袭性疾病可以通过疫苗接种来预防，这仍然是许多国家的主要疾病控制干预措施。这项研究检查了新南威尔士州与侵袭性疾病相关的循环流感嗜血杆菌菌株的基因组多样性，澳大利亚,在COVID-19大流行之前和期间。使用全基因组测序对代表2017年1月至2022年9月诊断的95例侵袭性流感嗜血杆菌感染（iHi）的96个分离株进行了分型和表征。这些病例由血清型A（n=24）引起，B（n=35），E(n=3),F(n=2)和NTHi(n=32)。在COVID-19大流行期间，iHi感染数量明显下降，随着血清型A（HIA）引起的iHi病例比例的相应增加，2022年恢复到大流行前的水平。由于PBP3突变或blaTEM-1的携带，与HIB或不可分型的iHi相关的15种分离株对β-内酰胺具有抗性。Further,在HIB分离株中观察到荚膜基因重复，但在HIA中未发现。这些发现为正在进行的iHi监测和控制提供了重要的基线基因组数据。
