In the past 12 years, several case reports have clearly demonstrated that Wohlfahrtiimonas chitiniclastica is capable of causing sepsis and bacteremia in humans. However, since most clinicians are not familiar with this species, little is known about its pathogenicity and treatment options while it is as rare but underestimated human pathogen. Therefore, a larger strain collection is required so that methods can be identified that are most suitable to obtain rapid and reliable identification. Moreover, the antimicrobial resistance profile needs to be elucidated in order to explore possible treatment options. Over a period of 6 years, we therefore have collected a total of 14 W. chitiniclastica isolates in routine diagnostics, which now served as the basis for a comprehensive characterization with respect to identification and antibiotic profiling. We compared the accuracy and convenience of several identification techniques in which MALDI-TOF MS and sequencing of the 16S rRNA gene have proven to be suitable for identification of W. chitiniclastica. In addition, whole genome sequencing (WGS)-based digital DNA-DNA hybridization (dDDH) was used as a reference method for strain identification, and surprised with the detection of a novel W. chitiniclastica subspecies. A combination of in silico and in vitro analyses revealed a first insight into the antimicrobial resistance profile and the molecular basis of antimicrobial resistance. Based on our findings, trimethoprim/sulfamethoxazole, levofloxacin, and cephalosporins (e.g., ceftazidime) may be the best antibiotics to use in order to treat infections caused by W. chitiniclastica, while resistance to fosfomycin, amikacin and tobramycin is observed.

在过去的 12 年中，多份病例报告清楚地表明， 几丁质假单胞菌能引起人类败血症和菌血症。然而，由于大多数临床医生不熟悉该物种，因此对其致病性和治疗方案知之甚少，而它是一种罕见但被低估的人类病原体。因此，需要更大的菌株收集，以便可以鉴定最适合获得快速和可靠鉴定的方法。此外，需要阐明抗菌素耐药性，以探索可能的治疗方案。因此，在 6 年的时间里，我们总共收集了 14W. chitiniclastica常规诊断中的分离株，现在作为鉴定和抗生素分析方面的综合表征的基础。我们比较了几种鉴定技术的准确性和便利性，其中 MALDI-TOF MS 和 16S rRNA 基因测序已被证明适用于鉴定W. chitiniclastica。 此外，基于全基因组测序 (WGS) 的数字 DNA-DNA 杂交 (dDDH) 被用作菌株鉴定的参考方法，并惊讶地发现了一种新的 W. chitiniclastica亚种。组合电脑模拟 和 体外分析揭示了对抗菌素耐药性概况和抗菌素耐药性的分子基础的初步了解。根据我们的研究结果，甲氧苄氨嘧啶/磺胺甲恶唑、左氧氟沙星和头孢菌素（例如头孢他啶）可能是治疗由以下因素引起的感染的最佳抗生素W. chitiniclastica，同时观察到对磷霉素、阿米卡星和妥布霉素的耐药性。