Human Erysipelothrix rhusiopathiae infection via bath water - case report and genome announcement

Abstract

Erysipelothrix rhusiopathiae is a facultative anaerobic, environmentally stable, Gram-positive rod that causes swine and avian erysipelas as a zoonotic pathogen. In humans, the main manifestations described are circumscribed erysipeloid, generalized erysipeloid, and endocarditis. Here, we report a 46-year-old female patient who presented to the physician because of redness and marked functio laesa of the hand, in terms of a pain-related restricted range of motion, and was treated surgically. E. rhusopathiae was detected in tissue biopsy. The source of infection was considered to be a pond in which both swine and, later, her dog bathed. The genome of the isolate was completely sequenced and especially the presumptive virulence associated factors as well as the presumptive antimicrobial resistance genes, in particular a predicted homologue to the multiple sugar metabolism regulator (MsmR), several predicted two-component signal transduction systems, three predicted hemolysins, two predicted neuraminidases, three predicted hyaluronate lyases, the surface protective antigen SpaA, a subset of predicted enzymes that potentially confer resistance to reactive oxygen species (ROS), several predicted phospholipases that could play a role in the escape from phagolysosomes into host cell cytoplasm as well as a predicted vancomycin resistance locus (vex23-vncRS) and three predicted MATE efflux transporters were investigated in more detail.

Keywords: Erysipelothrix rhusiopathiae; MSMR; Vancomycin Resistance; case report; erysipeloid; genome; swine erysipelas; vex23-vncRS.

Figure 1

(A) E. rhusopathiae Gram stain (magnification 1:1000, scale bar = 5 µm). The arrows indicate two Gram-positive rods with distinctly different lengths. (B) Gram stained slide with E. rhusopathiae (magnification 1:1000, scale bar = 5 µm). A decolorized (pseudo-) Gram-negative sample is shown. This phenomenon occurs regularly when preparing the microscopic specimen with colonies appearing “rough” on agar plates. (C) Growth of E. rhusopathiae on Schaedler KV agar. On the left, a smooth clearly circumscribed pinpoint colony can be seen, next to a bed of confluent colonies (right). (D) smooth and rough colonies on Columbia sheep blood agar.

Figure 2

Pie chart of RAST subsystems that were identifiable in the genome of E. rhusiopathiae 319078. The 19 most abundant subsystems at the “category” level identified by RAST are represented by a specific color in the legend on the right side of the figure.

Figure 3

Comparison of the vancomycin tolerance locus of Streptococcus pneumoniae R6 and Erysipelothrix rhusiopathiae 319078. In contrast to the vancomycin tolerance locus of S. pneumoniae R6, E. rhusiopathiae 319078 lacks the pep27 and vex1 genes, yet the microbial isolate has a vancomycin MIC of 32.0 mg/L.