50 - Streptococcal and Enterococcal Infections

Abstract

•First Described: Streptococci were first described in Germany in 1868 by Billroth.1 Enterococci were separated from the genus Streptococcus in 1984.2•Major Causes: In dogs and cats, the most common causes are Streptococcus canis, Streptococcus equi subsp. zooepidemicus, Enterococcus faecium, and Enterococcus faecalis, which are gram-positive coccoid bacteria.•Geographic Distribution: Worldwide.•Mode of Transmission: Direct contact usually; hospital environments can become contaminated with resistant enterococci. Organisms are usually commensals that invade opportunistically.•Major Clinical Signs: Clinically highly variable opportunistic infection; includes arthritis, bacteremia and endocarditis, bronchopneumonia, cervical lymphadenitis, cholangiohepatitis, discospondylitis, keratitis, mastitis, meningoencephalitis, necrotizing fasciitis and toxic shock syndrome (primarily S. canis), neonatal bacteremia, osteomyelitis, otitis externa, peritonitis, pharyngitis, postoperative incision or wound infections, pyometra or metritis, pyothorax, rhinitis and necrotizing sinusitis, and UTIs. Inflammation associated with these infections tends to be very pyogenic. In the lungs, these organisms are frequent components of polymicrobial aspiration pneumonia.•Differential Diagnoses: Primarily other gram-positive and gram-negative bacterial infections.•Human Health Significance: The role of dogs and cats in the transmission of Streptococcus pyogenes, a major human pathogen, (Lancefield group A) is commonly exaggerated. Streptococcal species that infect dogs and cats occasionally infect human patients.•Dogs and cats, or their contaminated environments, may also have the potential to serve as sources of MDR enterococcal infections for humans.