A Highly Pathogenic Strain of Staphylococcus sciuri Caused Fatal Exudative Epidermitis in Piglets

Staphylococcus sciuri are important human pathogens responsible for endocarditis, peritonitis, septic shock, urinary tract infection, pelvic inflammatory disease and wound infections. However, little information is known regarding the pathogenicity of S. sciuri to animals. From the pericardial fluid of a diseased piglet with exudative epidermitis (EE), we isolated a strain of Staphylococcus in pure culture. Surprisingly, this isolate was a member of S. sciuri rather than S. hyicus as identified by its biochemical traits and also by analysis of 23S ribosomal DNA using Internal Transcribed Spacer PCR. In addition, inoculation of newborn piglets with 1×10(10) CFU of the isolate by oral feeding or intra-muscular injection successfully reproduced EE in piglets, which suggested that the oral intake of the pathogen by the animals is one of the major routes of exposure. These unexpected findings prioritized S. sciuri as important zoonotic agents, which may have ramifications for human medicine

Gram's staining and molecular identification of Staphylococcus isolate.

<p>A. Gram's staining of the clinical Staphylococcus isolate. B. Identification of Staphylococcus subspecies by ITS-PCR analysis of ribosomal DNA in the isolates from natural EE (Lane 1) and experimental EE (Lane 2). C. Examination of exfoliative toxin gene of the Staphylococcus isolate by PCR. Lanes 1 through 5 represent the PCR products of Exh-A, Exh-B, Exh-C, Exh-D and 23s ribosomal DNA, respectively.</p

Clinical case of Exudative Epidermitis (EE) in piglets.

<p>A–B. Skin lesions (indicated by arrows) of five-day-old piglets with EE. C. Morbidity and mortality of suckling piglets from September of 2005 (n = 23), December of 2005 (n = 33) through March of 2006 (n = 95).</p

Reproduction of EE in newborn piglets inoculated with <i>S. sciuri</i> HBXX06 via <i>i.m.</i> injection or oral feeding.

<p>A. Four out of six newborn piglets treated with <i>S. sciuri</i> HBXX06 via <i>i.m.</i> injection or oral feeding at the dose of 1×10¹⁰ CFU per pig succumbed to death within 24 hours post infection. B–D. The skin lesions (indicated by arrows) of the survivals of the piglets on days 2, 3 and 4 respectively following oral feeding with 1×10¹⁰ CFU per piglet.</p