REASONS FOR PERFORMING STUDY Systemic administration of ceftiofur crystalline free acid (CCFA) may be a potential treatment for infectious endometritis caused by Streptococcus equi ssp. zooepidemicus (S.  zooepidemicus) and other susceptible bacterial organisms in the mare. OBJECTIVE To determine if i.m. administration of CCFA at the label dose will exceed the minimum inhibitory concentration...

Iceland is free of the major infectious diseases of horses. However, in 2010 an epidemic of respiratory disease of unknown cause spread through the country's native horse population of 77,000. Microbiological investigations ruled out known viral agents but identified the opportunistic pathogen Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) in diseased animals. We sequenced the genom...

Acute hemorrhagic pneumonia caused by Streptococcus zooepidemicus has emerged as a major disease of shelter dogs and greyhounds. S. zooepidemicus strains differing in multilocus sequence typing (MLST), protective protein (SzP), and M-like protein (SzM) sequences were identified from 9 outbreaks in Texas, Kansas, Florida, Nevada, New Mexico, and Pennsylvania. Clonality based on 2 or more isolate...

Streptococcus equi ssp. zooepidemicus (S. zooepidemicus, S.z) is one of the common pathogens that can cause septicemia, meningitis, and mammitis in domesticated species. M-like protein (SzP) is an important virulence factor of S. zooepidemicus and contributes to bacterial infection and antiphagocytosis. The interaction between SzP of S. zooepidemicus and porcine thioredoxin (TRX) was identified...

Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively investigated. Here we demonstrate the presence of a homologue of the Streptococcu...

Pulmonary infections may be induced in experimental animals by using several exposure routes. Inhalation of microbial aerosols is often viewed as the most relevant exposure route, although the comparability of either intranasal (i.n.) or intratracheal (i.t.) inoculation to aerosol inhalation is unclear. In these studies, the infection of mice with either Streptococcus zooepidemicus or influenza...

This work investigates the production of hyaluronic acid (H) by Streptococcus equi subsp. zooepidemicus in complex media formulated with peptones obtained from Scyliorhinus canicula viscera by-products. Initially, in batch cultures, the greatest productions were achieved using commercial media (3.03 g/L) followed by peptones from alcalase hydrolyzed viscera (2.32 g/L) and peptones from non-hydr...

Infection of bovine embryonic lung cells with bovine parainfluenza virus type 3 did not induce in vitro, virus-specific, hemadsorption-related adherence of Corynebacterium pyogenes, Haemophilus somnus, Staphylococcus aureus, Streptococcus zooepidemicus, Pasteurella haemolytica, Listeria monocytogenes, Escherichia coli, Pasteurella multocida, Brucella sp., or Salmonella typhimurium.

We describe a case of an infant with recurrent bacteremia caused by Streptococcus equi subsp. zooepidemicus, likely transmitted from mother to infant. Our case highlights the importance of an epidemiological history and molecular diagnostics in ascertaining insights into transmission, pathogenesis, and optimal management.