RESUMEN
The occurrence of carbapenemase-producing Enterobacteriaceae in livestock is considered as a threat for public health. In Germany, VIM-1-producing Escherichia (E.) coli sequence type (ST) 88 and Salmonella Infantis isolates harbouring blaVIM-1IncHI2 plasmids have been isolated from swine and poultry farms. A retrospective study was performed to determine if there was a broader distribution of VIM-1-positive isolates in any of the carbapenemase-positive swine farms. Selective incubation (carbapenem-containing broth) of 249 conserved cultures collected in three farms (2011-2012), allowed the detection of 40 blaVIM-1-positive isolates. Apart from the already known non-motile Salmonella Infantis isolate R25 (farm S1) and R27 (S2), a third isolate was recovered from farm S3. For E. coli, additional to isolates R29 and R178 (S2), 35 new isolates were identified in the same farm during all the sampling periods (three dates, 2011) and in samples from different animals, farm environment, manure and flies. The newly identified E. coli and Salmonella isolates showed similar genetic and phenotypic characteristics (XbaI-PFGE profiles, antimicrobial resistance patterns, plasmid content, phylogroups, antigenic formula) to those in the previously described strains, suggesting microevolution within the clonal lines within one fattening period. The study shows that persistence of carbapenemase-producing clonal lines in livestock farms is possible, and underlines the need for harmonised monitoring and surveillance studies to follow up the occurrence of such bacteria in European livestock.
Asunto(s)
Antibacterianos/farmacología , Infecciones por Enterobacteriaceae/veterinaria , Enterobacteriaceae/genética , Enfermedades de las Aves de Corral/microbiología , Enfermedades de los Porcinos/microbiología , Animales , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana/genética , Enterobacteriaceae/enzimología , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli/enzimología , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Granjas , Alemania/epidemiología , Ganado/microbiología , Plásmidos/genética , Aves de Corral , Enfermedades de las Aves de Corral/epidemiología , Estudios Retrospectivos , Salmonella/enzimología , Salmonella/genética , Salmonella/aislamiento & purificación , Porcinos , Enfermedades de los Porcinos/epidemiología , beta-Lactamasas/genéticaRESUMEN
A virulent Pseudomonas viridiflava-related bacterium has been identified as a new pathogen of soybean, one of the most important crops worldwide. The bacterium was recovered from forage soybean leaves with dark-reddish spots, and damage on petioles and pods was also observed. In contrast, common bean was not affected.
Asunto(s)
Glycine max/microbiología , Enfermedades de las Plantas/microbiología , Pseudomonas/clasificación , Pseudomonas/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Datos de Secuencia Molecular , Tipificación Molecular , Filogenia , Hojas de la Planta/microbiología , Pseudomonas/genética , Pseudomonas/fisiología , Técnica del ADN Polimorfo Amplificado Aleatorio , Análisis de Secuencia de ADNRESUMEN
One hundred and twenty pathogenic isolates of Pseudomonas syringae pv. phaseolicola recovered in Spain were subjected to biochemical and genomic typing, and investigated for virulence gene complement. Fifty-six were recovered from common beans (Phaseolus vulgaris) of the type Granja Asturiana, grown in a northern Spanish region (Asturias), and 64 from other common beans cultured in the neighbouring region of Castilla y León. Typing by PmeI digestion followed by pulsed-field gel electrophoresis revealed 27 profiles, with only three being common to both regions. Relationships between profiles distributed the isolates into two clusters: A (subdivided into subclusters A1 and A2) and B. Cluster A included all isolates from Granja Asturiana and about a quarter of the isolates from Castilla y León. Isolates from cluster A were negative for mannitol utilization and hybridized to probes for the argK-tox region responsible for phaseolotoxin production. Isolates that grouped in cluster B, which were only found in Castilla y León, were able to utilize mannitol but did not hybridize to probes for the argK-tox region. Separation of the isolates into three genomic groups, subsequently termed PphA1, PphA2 and PphB, was also supported by effector gene complement and location. In PphB, all effector genes tested (hopX1, hopF1, avrB2 and avrD1) mapped on chromosomal fragments, but faint hybridization of avrB2 with plasmids of about 40 kb was also observed. In PphA hopX1 mapped on the chromosome; in PphA1 avrB2 and avrD1 were carried on virulence plasmids (most of approx. 125 kb) and hopF1 was not detected, while in PphA2 the three genes were located on plasmids (approx. 75-160 kb). These results can be used as a framework to investigate the basis of regional variation in population structure, and for further epidemiological surveillance of P. syringae pv. phaseolicola.