CHARACTERIZATION OF STREPTOCOCCUS PNEUMONIAE ISOLATES FROM AUSTRIAN COMPANION ANIMALS AND HORSES

Igor Loncaric ¹ Maximilian Ginders ¹ Michael Leschnik ² Frank Künzel ² Doris Kampner ² Claudia Mikula ³ Georg Steindl ³ Andrea Feßler ⁴ Stefan Schwarz ⁴ Joachim Spergser ¹

¹Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna
²Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna
³National Reference Laboratory for Pneumococcus, Austrian Agency for Health and Food Safety, Graz
⁴Institute of Microbiology and Epizootics, Centre of Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin

The aim of the present study was to investigate the genetic relatedness and the antimicrobial resistance profile of a collection of Austrian Streptococcus (S.) pneumoniae isolates from companion animals and horses. A total of 11 non-repetitive isolates presumptively identified as
S. pneumoniae were obtained during routinely diagnostic activities between March 2009 and January 2017. Isolates were confirmed as S. pneumoniae by bile solubility and optochin susceptibility testing, matrix-assisted laser desorption-ionization–time of flight (MALDI-TOF) mass spectrometry, and sequence analysis of a part recA and the 16S rRNA gene. Isolates were further characterized by pneumolysin PCR and genotyped by multilocus sequence typing (MLST). Antimicrobial susceptibility testing was performed and resistance genes were detected by specific PCR. All isolates were serotyped.

Four sequence types (ST) (ST36, ST3546, ST6937 and ST6934) and four serotypes (3, 19A, 19F and 23F) were detected. One isolate displayed a multidrug-resistant pheno- and genotype.

The conducted study represents the first comprehensive investigation on characteristics of
S. pneumoniae isolates recovered from Austrian companion animals and horses. The obtained results indicate that common human sero- and sequence types may circulate in companion animals and horses. Moreover, common human S. pneumoniae clones implicated in causing invasive pneumococcal disease (IPD) were present in companion animals (a dog and a pet rat) suffering from encephalitis and pneumonia.

It is unclear whether this is a rare phenomenon or may be an emerging problem in the keeping of companion animals.