Data Sheet 1_Orthopedic infections associated with distinct Acinetobacter strains in rural area of Qingdao, China.docx

IntroductionAcinetobacter baumannii poses a profound global health threat because of multidrug resistance and its association with nosocomial infections. However, standard clinical diagnostics often report it together with other Acinetobacter species as A. baumannii-calcoaceticus complex (ABC), which unavoidably conceals the attribution of non-A. baumannii species. This study reported orthopedic infection cases associated with different Acinetobacter species and characterized the genomes of the culture isolates to evaluate their potential impact on the clinical treatment.
MethodsNine in-patients with A. baumannii-calcoaceticus complex identified by culture during hospitalization were enrolled by the Orthopedics Department from a local hospital in Qingdao, China. Their clinical data were reviewed. One ABC isolate from each patient was tested for drug susceptibility and subjected for whole-genome sequencing, followed by bioinformatic analyses.
ResultsThrough whole-genome analysis, nine ABC isolates were identified as six A. baumannii, two A. pittii, and one A. soli with distinct antibiotic resistance profiles and phylogenetic characteristics, indicating progressing pathogen transmission across broad geographic regions in One Health perspective. All A. baumannii and A. pittii strains carried multidrug resistance genes, while A. soli bore only amvA and rsmA. Phenotypically, eight isolates were susceptible to almost all the antibiotics tested, with only one A. baumannii being multidrug resistant. Despite this, eight patients received cephalosporins following positive reports of A. baumannii-calcoaceticus complex.
ConclusionOur study highlighted the limitation of current clinical diagnostic approaches for non-A. baumannii cases, which tended to be overtreated, and suggested that Acinetobacter etiology landscape should be explored further beyond A. baumannii to avoid antibiotic misuse.

引言 鲍曼不动杆菌（Acinetobacter baumannii）因多重耐药性及其与医院感染的关联，已构成严重的全球公共卫生威胁。然而，标准临床诊断通常将其与其他不动杆菌属物种一并归类为鲍曼不动杆菌-醋酸钙不动杆菌复合体（A. baumannii-calcoaceticus complex, ABC），这不可避免地掩盖了非鲍曼不动杆菌物种的致病归因。本研究报道了与不同不动杆菌属物种相关的骨科感染病例，并对培养分离株的基因组进行特征分析，以评估其对临床治疗的潜在影响。
方法 本研究纳入中国青岛某当地医院骨科收治的9例住院患者，这些患者住院期间经培养鉴定为鲍曼不动杆菌-醋酸钙不动杆菌复合体感染。研究人员回顾了患者的临床资料，对每例患者的1株ABC复合体分离株进行药物敏感性检测，并开展全基因组测序，随后进行生物信息学分析。
结果 经全基因组分析，9株ABC复合体分离株分别鉴定为6株鲍曼不动杆菌、2株皮特不动杆菌（A. pittii）及1株土壤不动杆菌（A. soli），它们具有不同的抗生素耐药谱与系统发育特征，从同一健康（One Health）视角来看，这提示病原体正跨广泛地理区域传播。所有鲍曼不动杆菌与皮特不动杆菌菌株均携带多重耐药基因，而土壤不动杆菌仅携带amvA与rsmA耐药基因。表型方面，8株分离株对所有受试抗生素几乎均敏感，仅1株鲍曼不动杆菌表现为多重耐药。尽管如此，在检测到鲍曼不动杆菌-醋酸钙不动杆菌复合体阳性后，共有8例患者接受了头孢菌素类药物治疗。
结论 本研究凸显了当前临床诊断方法在非鲍曼不动杆菌感染病例中的局限性，此类病例往往存在过度治疗的情况；同时建议，应进一步探究鲍曼不动杆菌以外的不动杆菌属病原体谱，以避免抗生素滥用。