RESUMEN
In order to control and eradicate epidemic cholera, we need to understand how epidemics begin, how they spread, and how they decline and eventually end. This requires extensive sampling of epidemic disease over time, alongside the background of endemic disease that may exist concurrently with the epidemic. The unique circumstances surrounding the Argentinian cholera epidemic of 1992-1998 presented an opportunity to do this. Here, we use 490 Argentinian V. cholerae genome sequences to characterise the variation within, and between, epidemic and endemic V. cholerae. We show that, during the 1992-1998 cholera epidemic, the invariant epidemic clone co-existed alongside highly diverse members of the Vibrio cholerae species in Argentina, and we contrast the clonality of epidemic V. cholerae with the background diversity of local endemic bacteria. Our findings refine and add nuance to our genomic definitions of epidemic and endemic cholera, and are of direct relevance to controlling current and future cholera epidemics.
Asunto(s)
Cólera/microbiología , Enfermedades Endémicas/prevención & control , Genoma Bacteriano/genética , Pandemias/prevención & control , Vibrio cholerae/genética , Argentina/epidemiología , Cólera/epidemiología , Cólera/prevención & control , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Historia del Siglo XIX , Historia del Siglo XX , Humanos , Anotación de Secuencia Molecular , Pandemias/historia , Filogenia , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN , Vibrio cholerae/aislamiento & purificación , Vibrio cholerae/patogenicidadRESUMEN
Escherichia coli O157 is an emergent pathogen associated with diarrhea, hemorrhagic colitis and hemolytic uremic syndrome. Meat products constitute an important transmission source of this microorganism. The aims of this study were to characterize E. coli O157 isolated from cattle and meat products collected from abattoirs and retail stores, to establish the clonal relatedness among regional isolates and to compare them with those in the national database. Between 2004 and 2013, 169 minced meat, 35 sausage and 216 carcass samples were analyzed. Thirteen E. coli O157 isolates were identified; 6 of which were O157:H7 and characterized as stx2c(vh-a)/eae/ehxA (n = 5) and stx2/eae/ehxA (n = 1). The 7 remaining isolates were non-toxigenic E. coli strains, and serotyped as O157:NT (n = 4), O157:NM (n = 1), O157:ND (n = 1) and O157:H16 (n = 1). The strains yielded different XbaI-PFGE patterns. Compared to the E. coli O157 isolates in the National Database, none of these patterns have been previously detected in strains of different origin in Argentina.
Asunto(s)
Bovinos/microbiología , Escherichia coli O157/aislamiento & purificación , Microbiología de Alimentos , Carne/microbiología , Animales , Argentina , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Reservorios de Enfermedades , Electroforesis en Gel de Campo Pulsado , Infecciones por Escherichia coli/transmisión , Escherichia coli O157/clasificación , Escherichia coli O157/genética , Escherichia coli O157/patogenicidad , Genes Bacterianos , Productos de la Carne/microbiología , Polimorfismo de Longitud del Fragmento de Restricción , Serotipificación , Virulencia/genéticaRESUMEN
Escherichia coli O157 es un patógeno emergente asociado a diarrea, colitis hemorrágica y síndrome urémico hemolítico. Los productos cárnicos constituyen una importante fuente de contaminación con este microorganismo. Los objetivos de este estudio fueron establecer la frecuencia de detección de E. coli O157 en productos cárnicos y media res en la provincia de Tucumán, caracterizar los factores de virulencia de los aislamientos obtenidos, establecer la relación clonal entre cepas regionales mediante electroforesis de campo pulsado y comparar con lo consignado en la base de datos nacional. Desde 2004 hasta 2013 se analizaron 169 muestras de carne picada, 35 embutidos y 216 esponjados de media res. Se identificaron 13 aislamientos de E. coli O157; 6 de ellos fueron O157:H7 productores de toxina Shiga y se caracterizaron como stx2c(vh-a)/eae/ehxA (n = 5) y stx2/eae/ehxA (n = 1); los 7 aislamientos de E. coli O157 no toxigénicos fueron O157:NT(n = 4),O157:NM (n = 1),O157:ND (n = 1) y O157:H16 (n = 1). Los patrones de PFGE fueron diferentes entre sí y de los registrados en la base de datos nacional. Se concluye que existe gran diversidad genética en los aislamientos de E. coli O157 circulantes en nuestra región
Escherichia coli O157 is an emergent pathogen associated with diarrhea, hemorrhagic colitis and hemolytic uremic syndrome. Meat products constitute an important transmission source of this microorganism. The aims of this study were to characterize E. coli O157 isolated from cattle and meat products collected from abattoirs and retail stores, to establish the clonal relatedness among regional isolates and to compare them with those in the national database. Between 2004 and 2013, 169 minced meat, 35 sausage and 216 carcass samples were analyzed. Thirteen E. coli O157 isolates were identified; 6 of which were O157:H7 and characterized as stx2c(vh-a)/eae/ehxA (n = 5) and stx2/eae/ehxA (n = 1). The 7 remaining isolates were non-toxigenic E. coli strains, and serotyped as O157:NT (n = 4), O157:NM (n = 1), O157:ND (n = 1) and O157:H16 (n = 1). The strains yielded different XbaI-PFGE patterns. Compared to the E. coli O157 isolates in the National Database, none of these patterns have been previously detected in strains of different origin in Argentina