Sydow Katharina, Eger Elias, Schwabe Michael, Heiden Stefan E, Bohnert Jürgen A, Franzenburg Sören, Jurischka Christoph, Schierack Peter, Schaufler Katharina
Pharmaceutical Microbiology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany.
Institute of Infection Medicine, Christian-Albrecht University Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany.
Microorganisms. 2022 Oct 19;10(10):2063. doi: 10.3390/microorganisms10102063.
is a common member of the intestinal flora of vertebrates. In addition to opportunistic representatives, hypervirulent (hvKp) and antibiotic-resistant (ABR-Kp) occur. While ABR-Kp isolates often cause difficult-to-treat diseases due to limited therapeutic options, hvKp is a pathotype that can infect healthy individuals often leading to recurrent infection. Here, we investigated the clinical isolate PBIO3459 obtained from a blood sample, which showed an unusual colony morphology. By combining whole-genome and RNA sequencing with multiple in vitro and in vivo virulence-associated assays, we aimed to define the respective subtype and explore the unusual phenotypic appearance. We demonstrate that PBIO3459 belongs to sequence type (ST)20 and carries no acquired resistance genes, consistent with phenotypic susceptibility tests. In addition, the isolate showed low-level virulence, both at genetic and phenotypic levels. We thus suggest that PBIO3459 is an opportunistic (commensal) isolate. Genomic comparison of PBIO3459 with closely related ABR-Kp ST20 isolates revealed that they differed only in resistance genes. Finally, the unusual colony morphology was mainly associated with carbohydrate and amino acid transport and metabolism. In conclusion, our study reveals the characteristics of a sepsis isolate and suggests that opportunistic representatives likely acquire and accumulate antibiotic resistances that subsequently enable their emergence as ABR-Kp pathogens.
是脊椎动物肠道菌群的常见成员。除了机会性代表菌株外，还存在高毒力（hvKp）和耐抗生素（ABR-Kp）菌株。虽然ABR-Kp分离株由于治疗选择有限，常导致难以治疗的疾病，但hvKp是一种致病型，可感染健康个体，常导致反复感染。在此，我们研究了从一份血液样本中获得的临床分离株PBIO3459，它表现出不寻常的菌落形态。通过将全基因组和RNA测序与多种体外和体内毒力相关试验相结合，我们旨在确定各自的亚型，并探索这种不寻常的表型外观。我们证明PBIO3459属于序列型（ST）20，且不携带获得性耐药基因，这与表型药敏试验结果一致。此外，该分离株在基因和表型水平上均表现出低水平毒力。因此，我们认为PBIO3459是一种机会性（共生）分离株。PBIO3459与密切相关的ABR-Kp ST20分离株的基因组比较显示，它们仅在耐药基因方面存在差异。最后
