Simone Schuller

Background Enterobacter hormaechei producing the carbapenemase OXA-48 was identified repeatedly in infections in companion animals hospitalized at a Swiss veterinary clinic where OXA-48-producing Klebsiella pneumoniae was previously reported. Objectives To determine the genetic relatedness of animal and human E. hormaechei strains collected in Switzerland during 2017–22 and their mobile genetic elements. Methods Hybrid assemblies for phylogenetic and comparative analysis of animal (n = 9) and human (n = 25) isolates were obtained by sequencing with Illumina, PacBio and Oxford Nanopore Technologies. Antimicrobial susceptibility was tested by broth microdilution. Results The animal strains were identified as E. hormaechei subsp. xiangfangensis ST114 (n = 6) and ST418 (n = 2), and E. hormaechei subsp. hoffmannii ST78 (n = 1). Human E. hormaechei belonged to subspecies steigerwaltii (n = 10), xiangfangensis (n = 13), hoffmannii (n = 1) and hormaechei (n = 1), with a heterogeneous ST distribution differing from the animal strains, except for two ST114. Core-gene SNP analysis confirmed the clonality of the animal ST114 and ST418 isolates (0 to 10 SNPs), and close relatedness of animal and human ST114 strains (80–120 SNPs). The strains harboured the blaOXA-48 gene on ca. 63 kb IncL-type plasmids (n = 27); on ca. 72 kb IncL plasmids co-harbouring blaCTX-M-14 (n = 2); and on ca. 150–180 kb IncFIB (n = 4) or hybrid IncFIB/IncL (n = 1) plasmids. The blaOXA-48-harbouring plasmids and the blaDHA-1-carrying ISCR1 element in one animal ST114 and both ST418 clones were likely acquired from previously spreading K. pneumoniae strains. Conclusions Common ecological niches favour the spread of plasmid-borne carbapenemases among Enterobacterales and the emergence of MDR E. hormaechei clones.

Background Procalcitonin (PCT) is a well‐established biomarker for bacterial infection in human patients. Objectives We aimed to analyze the kinetics of plasma PCT (pPCT) in healthy dogs and dogs with canine cranial cruciate ligament (CCL) rupture undergoing tibial plateau leveling osteotomy (TPLO). Methods This prospective, longitudinal study included 15 healthy dogs and 25 dogs undergoing TPLO. Hematology, pPCT, and C‐reactive protein (CRP) were assessed on 3 consecutive days in healthy dogs and 1 day preoperatively and days 1, 2, 10, and 56 postoperatively. Inter‐ and intraindividual variability of pPCT were assessed in healthy dogs. Median pPCT concentrations of dogs with CCL rupture preoperatively were compared with healthy controls, and median pPCT concentrations, as well as percentage change post anesthesia, arthroscopy, and TPLO, were compared with baseline. For the correlation analysis, the Spearman rank correlation test was used. Results Inter‐ and intraindividual variabilities of pPCT in healthy dogs were 36% and 15%, respectively. Median baseline pPCT concentrations were not significantly different between healthy dogs (118.9 pg/mL; IQR: 75.3‐157.3 pg/mL) and dogs undergoing TPLO (95.9 pg/mL; IQR: 63.8‐117.0 pg/mL). Plasma PCT concentrations were significantly lower immediately post‐ than preoperatively ( P < 0.001). CRP, WBC, and neutrophil concentrations increased significantly on post‐OP day 2 and had normalized by day 10. Conclusions These results indicate that CCL rupture, as well as anesthesia, arthroscopy, and TPLO combined, are not associated with increased pPCT concentrations in dogs with uncomplicated recovery. Considering the high intraindividual variability, individual serial measurements rather than a population‐based reference interval should be considered.