Li Xin-Xin, Xiao Shu-Zhen, Gu Fei-Fei, He Wei-Ping, Ni Yu-Xing, Han Li-Zhong
Department of Clinical Microbiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Front Public Health. 2020 Mar 27;8:95. doi: 10.3389/fpubh.2020.00095. eCollection 2020.
The serotype and antimicrobial resistance of in adult patients have changed due to the application of antimicrobials and type b (Hib) vaccine worldwide. However, the epidemiologic characteristics of in Shanghai are still unavailable. To determine the serotype distribution, antimicrobial resistance and multilocus sequence type (MLST) of in adult patients in Shanghai. A total of 51 clinical isolates from adult patients were consecutively collected. Serotypes were determined according to specific capsule gene, , amplified by PCR. Antimicrobial susceptibility test was carried out by the broth microdilution method. β-lactamase production was detected by cefinase disk and the gene were amplified and sequenced to determine the penicillin binding protein 3 (PBP3) mutation. Molecular epidemiology was performed by MLST analyses. All isolates studied were nontypeable (NTHi) and three of them (5.88%) caused invasive infection. The resistant rates of ampicillin and trimethoprim/sulfamethoxazole were both 45.10%. One third of these isolates produced TEM-1 type β-lactamase and 11.76% were β-lactamase negative ampicillin resistant strains (BLNAR). The PBP3 mutation was detected in 74.51% of the isolates, of which 12 belonged to group III. A total of 36 sequence types (STs) were identified among all isolates. Four isolates of ST103 (7.84%) all produced β-lactamase without mutation of PBP3. infections among adults in Shanghai are predominately caused by NTHi with genetic diversity among adult patients. The prevalence of both β-lactamase production and PBP3 mutation may contribute to high ampicillin resistance rate in Shanghai.
由于全球范围内抗菌药物的应用和b型流感嗜血杆菌（Hib）疫苗的接种，成年患者中[细菌名称未给出]的血清型和抗菌药物耐药性发生了变化。然而，上海地区[细菌名称未给出]的流行病学特征仍不清楚。为了确定上海成年患者中[细菌名称未给出]的血清型分布、抗菌药物耐药性和多位点序列类型（MLST）。连续收集了51株来自成年患者的临床分离株。根据通过PCR扩增的特定荚膜基因[基因名称未给出]确定血清型。采用肉汤微量稀释法进行抗菌药物敏感性试验。用头孢菌素酶纸片检测β-内酰胺酶的产生，并对[基因名称未给出]基因进行扩增和测序以确定青霉素结合蛋白3（PBP3）突变。通过MLST分析进行分子流行病学研究。所有研究的分离株均为不可分型[细菌名称未给出]（NTHi），其中3株（5.88%）引起侵袭性感染。氨苄西林和甲氧苄啶/磺胺甲恶唑的耐药率均为45.10%。这些分离株中有三分之一产生TEM-1型β-内酰胺酶，11.76%为β-内酰胺酶阴性氨苄西林耐药菌株（BLNAR）。74.51%的分离株检测到PBP3突变，其中12株属于III组。在所有分离株中总共鉴定出36种序列类型（STs）。4株ST103分离株（7.84%）均产生β-内酰胺酶且PBP3无突变。上海成年患者中的[细菌名称未给出]感染主要由NTHi引起，成年患者中存在遗传多样性。β-内酰胺酶产生和PBP3突变的流行可能导致上海地区氨苄西林耐药率较高。
