RESUMEN
Streptococcus equi subspecies zooepidemicus (SEZ) is a commensal bacterium of horses and causes infections in mammalian species, including humans. Historically, virulent strains of SEZ caused high mortality in pigs in China and Indonesia, while disease in the U.S. was infrequent. More recently, high mortality events in sows were attributed to SEZ in North America. The SEZ isolates from these mortality events have high genetic similarity to an isolate from an outbreak in China. Taken together, this may indicate SEZ is an emerging threat to swine health. To generate a disease model and evaluate the susceptibility of healthy, conventionally raised pigs to SEZ, we challenged sows and five-month-old pigs with an isolate from a 2019 mortality event. Pigs were challenged with a genetically similar guinea pig isolate or genetically distinct horse isolate to evaluate comparative virulence. The swine isolate caused severe systemic disease in challenged pigs with 100 % mortality. Disease manifestation in sows was similar to field reports: lethargy/depression, fever, reluctance to rise, and high mortality. The guinea pig isolate also caused severe systemic disease; however, most five-month-old pigs recovered. In contrast, the horse isolate did not cause disease and was readily cleared from the respiratory tract. In conclusion, we were able to replicate disease reported in the field. The results indicate differences in virulence between isolates, with the highest virulence associated with the swine isolate. Additionally, we generated a challenge model that can be used in future research to evaluate virulence factors and disease prevention strategies.
Asunto(s)
Enfermedades de los Caballos , Infecciones Estreptocócicas , Streptococcus equi , Enfermedades de los Porcinos , Replicación Viral , Animales , Modelos Animales de Enfermedad , Femenino , Cobayas , Enfermedades de los Caballos/virología , Caballos , Infecciones Estreptocócicas/veterinaria , Infecciones Estreptocócicas/virología , Streptococcus equi/fisiología , Porcinos , Enfermedades de los Porcinos/virología , Replicación Viral/fisiologíaRESUMEN
Plasmid-mediated polymyxin resistance encoded by mcr-1 has increased public health concerns due to the potential for rapid horizontal transfer. Here, we report the complete genome sequence of colistin-resistant Escherichia coli Antibiotic Resistance Isolate Bank number 0346, harboring a plasmid-borne mcr-1 gene.
RESUMEN
The emergence of plasmid-mediated polymyxin resistance encoded by mcr-1 has heightened public health concerns due to the potential for rapid horizontal transfer. Here, we report the complete genome sequence of Escherichia coli AR Bank #0349, which exhibits resistance to colistin encoded by a plasmid-borne mcr-1 gene.