Xu Xiaomin, Liang Shanyan, Li Xin, Hu Wenjin, Li Xi, Lei Liusheng, Lin Huai
Department of Hospital Infection Management, Ningbo No.2 Hospital, Ningbo, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
Front Microbiol. 2024 Aug 5;15:1459466. doi: 10.3389/fmicb.2024.1459466. eCollection 2024.
() is a deadly opportunistic human pathogen with high mortality worldwide. Notably, climate warming is likely to expand its geographical range and increase the infection risk for individuals in coastal regions. However, due to the absence of comprehensive surveillance systems, the emergence and characteristics of clinical isolates remain poorly understood in China.
In this study, we investigate antibiotic resistance, virulence including serum resistance, and hemolytic ability, as well as molecular characteristics of 21 isolates collected from patients in Ningbo, China.
The results indicate that all isolates have been identified as potential virulent C type, with the majority (16 of 21) classified as B type. Furthermore, these isolates exhibit a high level of antibiotic resistance, with 66.7% resistance to more than three antibiotics and 61.9% possessing a multiple antibiotic resistance (MAR) index exceeding 0.2. In terms of virulence, most isolates were categorized as grade 1 in serum resistance, with one strain, S12, demonstrating intermediate sensitivity in serum resistance, belonging to grade 3. Whole genome analysis disclosed the profiles of antibiotic resistance genes (ARGs) and virulence factors (VFs) in these strains. The strains share substantial VF genes associated with adherence, iron uptake, antiphagocytosis, toxin, and motility. In particular, key VFs such as capsule (CPS), lipopolysaccharide (LPS), and multifunctional autoprocessing repeats-in-toxin (MARTX) are prevalent in all isolates. Specifically, S12 possesses a notably high number of VF genes (672), which potentially explains its higher virulence. Additionally, these strains shared six ARGs, namely, , , var, , and , which likely determine their antibiotic resistance phenotype.
Overall, our study provides valuable baseline information for clinical tracking, prevention, control, and treatment of infections.
（病原体名称未给出）是一种致命的人类机会性病原体，在全球范围内死亡率很高。值得注意的是，气候变暖可能会扩大其地理范围，并增加沿海地区个体的感染风险。然而，由于缺乏全面的监测系统，在中国临床分离株的出现情况和特征仍知之甚少。
在本研究中，我们调查了从中国宁波患者中收集的21株分离株的抗生素耐药性、包括血清耐药性在内的毒力和溶血能力，以及分子特征。
结果表明，所有分离株均被鉴定为潜在的强毒株C型，大多数（21株中的16株）被归类为B型。此外，这些分离株表现出高水平的抗生素耐药性，66.7%对三种以上抗生素耐药，61.9%的多重耐药（MAR）指数超过0.2。在毒力方面，大多数分离株在血清耐药性方面被归类为1级，其中一株S12在血清耐药性方面表现出中等敏感性，属于3级。全基因组分析揭示了这些菌株中抗生素耐药基因（ARGs）和毒力因子（VFs）的图谱。这些菌株共享大量与黏附、铁摄取、抗吞噬、毒素和运动性相关的VF基因。特别是，关键的VF如荚膜（CPS）、脂多糖（LPS）和多功能自加工毒素重复序列（MARTX）在所有分离株中普遍存在。具体而言，S12拥有数量显著高的VF基因（672个），这可能解释了其较高的毒力。此外，这些菌株共享六个ARGs，即……（此处原文未完整列出基因名称），这可能决定了它们的抗生素耐药表型。
总体而言，我们的研究为（病原体名称未给出）感染的临床追踪、预防、控制和治疗提供了有价值的基线信息。
