The rapid dissemination of extended-spectrum β-lactamases (ESBLs)-producing Enterobacterales from different spheres worldwide over recent years has become a serious problem in both human and veterinary medicine. CTX-M-3-type ESBL has only been reported on few occasions, and in Brazil the bla_CTX-M-3 gene has been identified only once in clinical strains. In this study, we aimed to molecularly characterize a hypermucoviscous (hm), hypervirulent (hv), and extensively drug-resistant (XDR) Klebsiella pneumoniae strain isolated from a lung tissue culture of an infected elephant. The A246 strain belonged to ST2121 and presented hm phenotype, hypervirulence-associated genes, and carried bla_CTX-M-3 and plasmid-mediated quinolone resistance genes (qnrB2 and qnrS1) on an IncFII-IncQ1-IncM1 multireplicon plasmid (pA246-CTX-M-3, ∼ 162 kb). A novel genetic context of bla_CTX-M-3, in which a 482-bp ISEcp1 was truncated by an IS26, was also harbored by pA246-CTX-M-3. Furthermore, in vivo experiments revealed that the hm/hv A246 strain killed 100 % of the Galleria mellonella larvae at 72 h post-infection. Our findings evidence the intercontinental dissemination of a rare K. pneumoniae ST2121 and the multidrug resistance IncFII-IncQ1-IncM1 plasmid. Therefore, to the best of our knowledge, this is the first report of an XDR K. pneumoniae coproducing CTX-M-3, QnrB2, and QnrS1 isolated from captive wild animals.

近年来，来自世界各地不同领域的产广谱β-内酰胺酶（ESBLs）肠杆菌的快速传播已成为人类和兽医学的严重问题。CTX-M-3型ESBL仅在少数情况下有报道，在巴西，bla _CTX-M-3基因在临床菌株中仅被鉴定过一次。在这项研究中，我们旨在分子表征从感染大象的肺组织培养物中分离出的高粘液粘液（hm），高毒力（hv）和广泛耐药（XDR）肺炎克雷伯菌。A246菌株属于ST2121，具有hm表型，高毒力相关基因，并携带bla _CTX-M-3以及IncFII-IncQ1-IncM1多复制质粒（pA246-CTX-M-3，〜162 kb）上的质粒介导的喹诺酮抗性基因（qnrB2和qnrS1）。pA246-CTX-M-3也带有bla _CTX-M-3的新遗传背景_，其中482 bp IS Ecp1被IS 26截短。此外，在体内实验揭示的HM / HV A246菌株杀死100％的蜡螟在72小时后感染的幼虫。我们的发现证明了一种罕见的肺炎克雷伯菌在洲际传播。ST2121和多药耐药性IncFII-IncQ1-IncM1质粒。因此，据我们所知，这是从圈养野生动物中分离产生的XDR肺炎克雷伯菌的第一个报道，即共生产CTX-M-3，QnrB2和QnrS1。