Necrotizing fasciitis in captive juvenileCrocodylus porosuscaused byStreptococcus agalactiae: an outbreak and review of the animal and human literature

Abstract

SUMMARYWe observed an outbreak of necrotizing fasciitis associated withStreptococcus agalactiaeinfection in a group of juvenile saltwater crocodiles (Crocodylus porosus). We undertook screening of crocodiles and the environment to clarify the source of the outbreak and evaluated the isolates cultured from post-mortem specimens with molecular methods to assess clonality and the presence of known group B streptococcal virulence determinants. The isolates were indistinguishable by pulsed-field gel electrophoresis. They were a typical serotype Ia strain with the Cα-like protein gene, epsilon (oralp1), the mobile genetic elements IS381ISSag1and ISSag2, and belonged to multi-locus sequence type (ST) 23. All of these characteristics suggest they were probably of human origin. We review the medical and veterinary literature relating toS. agalactiaenecrotizing fasciitis, epidemiology and virulence determinants.