Detection of Various Streptococcus spp. and Their Antimicrobial Resistance Patterns in Clinical Specimens from Austrian Swine Stocks

Abstract

Knowledge of pathogenic potential, frequency and antimicrobial resistance patterns of porcine Streptococcus (S.) spp. other than S. suis is scarce. Between 2016 and 2020, altogether 553 S. spp. isolates were recovered from clinical specimens taken from Austrian swine stocks and submitted for routine microbiological examination. Antimicrobial susceptibility testing towards eight antimicrobial substances was performed using disk diffusion test. All isolates from skin lesions belonged to the species S. dysgalactiae subspecies equisimilis (SDSE). S. hyovaginalis was mainly isolated from the upper respiratory tract (15/19) and S. thoraltensis from the genitourinary tract (11/15). The majority of S. suis isolates were resistant to tetracycline (66%), clindamycin (62%) and erythromycin (58%). S. suis isolates from the joints had the highest resistance rates. S. suis and SDSE isolates resistant to tetracycline were more likely to be resistant to erythromycin and clindamycin (p < 0.01). Results show that different species of Streptococcus tend to occur in specific body sites. Nevertheless, a statement whether these species are colonizers or potential pathogens cannot be given so far. High resistance rates of S. suis towards tetracyclines and erythromycin and high recovery rates of S. suis from lung tissue should be considered when treating pigs with respiratory diseases.

National Monitoring of Veterinary-Dispensed Antimicrobials for Use on Pig Farms in Austria: 2015–2020

“…Similar resistance patterns have also been reported in studies in Austria, where tetracycline resistance was reported among 66% of Streptococcus suis isolates (increasing up to 88% of Sc. suis isolates obtained from joints) and 67.7% of Escherichia coli isolates obtained from piglets with diarrhoea [ 31 , 32 ].…”

Cavernous sinus thrombosis: An insidious and dangerous “do‐not‐miss” diagnosis

“…In this patient, the blood cultures that were grown before antibiotic use revealed the presence of S . thoraltensis , a novel opportunistic pathogen that colonizes the upper respiratory tract and belongs to the alpha‐hemolytic Streptococcus genus 9 . The localized inflammatory response of the sphenoid sinus could lead to colonizing bacterial invasion of the bloodstream, resulting in transient bacteremia.…”

Coinfections and Phenotypic Antimicrobial Resistance in Actinobacillus pleuropneumoniae Strains Isolated From Diseased Swine in North Western Germany—Temporal Patterns in Samples From Routine Laboratory Practice From 2006 to 2020

“…and Streptococcus spp. (25)(26)(27). Inoculated plates were incubated for 48 h at 37 • C under standard atmospheric conditions, while chocolate blood agar was incubated in an 8% CO 2 atmosphere.…”