Abstract：
Acinetobacter baumannii has become a prominent nosocomial pathogen, primarily owing to its remarkable ability to rapidly acquire resistance to a wide range of antimicrobial agents and its ability to persist in diverse environments. However, there is a lack of data on the molecular epidemiology and its potential implications for public health of A. baumannii strains exhibiting clinically significant resistances that originate from non-clinical environments. Therefore, the genetic characteristics and resistance mechanisms of 80 A. baumannii-calcoaceticus (ABC) complex isolates, sourced from environments associated with poultry and pig production, municipal wastewater treatment plants (WWTPs), and clinical settings, were investigated. In total, our study classified 54 isolates into 29 previously described sequence types (STs), while 26 isolates exhibited as-yet-unassigned STs. We identified a broad range of A. baumannii STs originating from poultry and pig production environments (e.g., ST10, ST238, ST240, ST267, ST345, ST370, ST372, ST1112 according to Pasteur scheme). These STs have also been documented in clinical settings worldwide, highlighting their clinical significance. These findings also raise concerns about the potential zoonotic transmission of certain STs associated with livestock environments. Furthermore, we observed that clinical isolates exhibited the highest diversity of antimicrobial resistance genes (ARGs). In contrast to non-clinical isolates, clinical isolates typically carried a significantly higher number of ARGs, ranging from 10 to 15. They were also the exclusive carriers of biocide resistance genes and acquired carbapenemases (blaOXA-23, blaOXA-58, blaOXA-72, blaGIM-1, blaNDM-1). Additionally, we observed that clinical strains displayed an increased capacity for carrying plasmids and undergoing genetic transformation. This heightened capability could be linked to the intense selective pressures commonly found within clinical settings. Our study provides comprehensive insights into essential aspects of ABC isolates originating from livestock-associated environments and clinical settings. We explored their resistance mechanisms and potential implications for public health, providing valuable knowledge for addressing these critical issues.
摘要：
鲍曼不动杆菌已成为一种突出的院内致病菌,这主要是由于其快速获得对多种抗微生物剂的耐药性的显着能力以及在多种环境中持续存在的能力。然而,缺乏关于鲍曼不动杆菌菌株的分子流行病学及其对公共卫生的潜在影响的数据,鲍曼不动杆菌菌株表现出源自非临床环境的临床显著耐药性.因此,80株鲍曼不动杆菌(ABC)复合分离株的遗传特性和抗性机制,来自与家禽和猪生产相关的环境，市政污水处理厂（WWTP），和临床环境，被调查了。总的来说,我们的研究将54个分离株分为29个先前描述的序列类型(STs)，而26个分离株表现出尚未分配的STs。我们确定了广泛的鲍曼不动杆菌来自家禽和猪生产环境(例如，ST10、ST238、ST240、ST267、ST345、ST370、ST372、ST1112根据巴斯德方案)。这些STs也已在世界各地的临床环境中得到记录，强调其临床意义。这些发现还引起了人们对与牲畜环境相关的某些STs的潜在人畜共患病传播的担忧。此外，我们观察到临床分离株表现出最高多样性的抗菌素耐药基因(ARGs).与非临床分离株相比，临床分离株通常携带明显更多的ARGs，范围从10到15。它们也是杀生物剂抗性基因和获得性碳青霉烯酶(blaOXA-23、blaOXA-58、blaOXA-72、blaGIM-1、blaNDM-1)的唯一携带者。此外,我们观察到临床菌株显示携带质粒和进行遗传转化的能力增加。这种增强的能力可能与临床环境中常见的强烈选择压力有关。我们的研究提供了对源自牲畜相关环境和临床环境的ABC分离株的基本方面的全面见解。我们探讨了它们的抗性机制和对公共卫生的潜在影响，为解决这些关键问题提供有价值的知识。
