RESUMEN
The key of success of extraintestinal pathogenic Escherichia coli (ExPEC) to colonize niches outside the intestinal tract and to establish infection is the coordinated action of numerous virulence and fitness factors. The so-called high-pathogenicity island (HPI), responsible for synthesis, secretion and uptake of the siderophore yersiniabactin, proved to be an important virulence determinant. In this study we investigated the interaction of the flagellum-mediated motility and the HPI. The impairment of yersiniabactin production by deletion of irp2 or ybtA affected significantly motility. The gain of yersiniabactin production improved motility in both pathogenic and non-pathogenic E. coli strains. The loss of flagella expression had no adverse effect on the HPI. Strikingly, external iron abundance was not able to suppress activation of the HPI during motility. The HPI activity of swarming bacteria was comparable to iron deplete conditions, and could even be maximized by supplementing excessive iron. This fact is the first description of a regulatory mechanism, which does not follow the known hierarchical regulation of siderophore systems. Transcriptional reporter fusions of the ybtA promoter demonstrated that the entire promoter region with all YbtA binding sites is necessary for complete induction in both HPI-positive and HPI-negative strains. Altogether, these results suggest that the HPI is part of a complex regulatory network, which orchestrates various virulence mechanisms to optimize the overall fitness of ExPEC.
Asunto(s)
Movimiento Celular/genética , Escherichia coli Patógena Extraintestinal/genética , Flagelos/genética , Islas Genómicas/genética , Proteínas Bacterianas/genética , Escherichia coli Patógena Extraintestinal/patogenicidad , Proteína 2 Reguladora de Hierro/genética , Fenoles/metabolismo , Regiones Promotoras Genéticas , Tiazoles/metabolismo , Transactivadores/genética , Yersinia/genética , Yersinia/patogenicidadRESUMEN
No disponible
Asunto(s)
Humanos , Femenino , Adulto , Zoonosis/microbiología , Zoonosis/transmisión , Monitoreo Epidemiológico , Infecciones Bacterianas/epidemiología , Leptospirosis/diagnóstico , Leptospirosis/epidemiología , Doxiciclina/uso terapéutico , Zoonosis/epidemiología , Tomografía Computarizada de Emisión/métodos , Tomografía Computarizada de Emisión/tendencias , Linfadenitis/complicaciones , Linfadenitis/epidemiología , Yersinia/aislamiento & purificación , Yersinia/patogenicidadRESUMEN
The results of the interaction of bacteria of the genera Yersinia, Listeria and Salmonella, pathogenic for humans and animals, with callus cultures of different plant species are presented. As revealed in this study, complicated interactions developed between bacteria and plant cells. Plant cells were shown to be highly sensitive to the action of bacteria. Yersinia, Listeria and Salmonella were found to be capable of callus damage. The influence of plant cells on bacteria was more complicated: both the stimulation of bacterial growth and its inhibition were noted, depending on the time of cultivation.
Asunto(s)
Listeria monocytogenes/patogenicidad , Plantas/microbiología , Salmonella enteritidis/patogenicidad , Yersinia/patogenicidad , Células Cultivadas , Medios de Cultivo , Listeria monocytogenes/crecimiento & desarrollo , Panax/microbiología , Enfermedades de las Plantas/microbiología , Plantas Medicinales , Salmonella enteritidis/crecimiento & desarrollo , Factores de Tiempo , Yersinia/crecimiento & desarrolloAsunto(s)
Enfermedades Reumáticas/microbiología , Yersinia/patogenicidad , Animales , Artritis/microbiología , Artritis Reactiva/etiología , Artritis Reumatoide/microbiología , Eritema Nudoso/microbiología , Femenino , Antígenos HLA/análisis , Humanos , Masculino , Cardiopatía Reumática/microbiología , Factores de Tiempo , Yersiniosis/complicaciones , Yersiniosis/inmunología , Yersiniosis/microbiologíaRESUMEN
A total of forty-five guinea pigs were injected subcutaneously with 0.1 cu cm carboneum tetracholoratum each and were infected with Yersinia enterocolitica serotype 9. Part of the animals (31) were treated at the 24th hour following infection with omnopon (a morphine preparation). All infected guinea pigs developed an infectious process manifested by dystrophic and inflammatory changes in the liver, intestine, spleen, lymph nodes and lungs. Those treated with omnopon manifested a more acute infectious process. After the 13--20th day of infection the lesions became more weakly expressed. On the 50th day the inflammatory reaction was observed in the lymph nodes and spleen only. The mortality rate in both groups was about 50 per cent.