Laboratory host systems for extraneous agent testing in avian live virus vaccines: problems encountered.

The regulation for batch testing of avian live viral vaccines for extraneous agents was modified recently in order to reduce animal use, and routine batch testing had to be adapted to this new regulation. As a result, however, some tests have become more complicated and time-consuming. Due to systematic technical problems, the new methods required could only be applied to a small proportion of the batches produced.

Intestine and environment of the chicken as reservoirs for extraintestinal pathogenic Escherichia coli strains with zoonotic potential.

Although research has increasingly focused on the pathogenesis of avian pathogenic Escherichia coli (APEC) infections and the "APEC pathotype" itself, little is known about the reservoirs of these bacteria. We therefore compared outbreak strains isolated from diseased chickens (n = 121) with nonoutbreak strains, including fecal E. coli strains from clinically healthy chickens (n = 211) and strains from their environment (n = 35) by determining their virulence gene profiles, phylogenetic backgrounds, responses to chicken serum, and in vivo pathogenicities in a chicken infection model.

The chicken as a natural model for extraintestinal infections caused by avian pathogenic Escherichia coli (APEC).

E. coli infections in avian species have become an economic threat to the poultry industry worldwide. Several factors have been associated with the virulence of E.

Clonality of Enterococcus faecalis associated with amyloid arthropathy in chickens evaluated by multilocus sequence typing (MLST).

The aim of the study was to evaluate the clonality of 21 strains of Enterococcus faecalis associated with arthritis and amyloid arthropathy by multilocus sequence typing (MLST). The strains originated from five countries. Fifteen of the 21 strains demonstrated the same sequence type, ST82, including a reference amyloid arthropathy strain from the Netherlands.

Avian pathogenic, uropathogenic, and newborn meningitis-causing Escherichia coli: how closely related are they?

Avian pathogenic Escherichia coli (APEC), uropathogenic E. coli (UPEC), and newborn meningitis-causing E. coli (NMEC) establish infections in extraintestinal habitats (extraintestinal pathogenic E.

Investigations of the vertical transmission of Erysipelothrix rhusiopathiae in laying hens.

Erysipelas was diagnosed in a layer breeder flock in Sweden in 2002. Although vertical transmission of Erysipelothrix rhusiopathiae has not been previously described in chickens, the potential of erysipelas infection to adversely affect hatching eggs was of concern. To clarify the possible impact of erysipelas on hatching eggs and their progeny, an experiment was done using 200 hatching eggs collected from the infected flock.

Rapid detection of virulence-associated genes in avian pathogenic Escherichia coli by multiplex polymerase chain reaction.

Based on recently published prevalence data of virulence-associated factors in avian pathogenic Escherichia coli (APEC) and their roles in the pathogenesis of colibacillosis, we developed a multiplex polymerase chain reaction (PCR) as a molecular tool supplementing current diagnostic schemes that mainly rely on serological examination of strains isolated from diseased birds. Multiple isolates of E. coli from clinical cases of colibacillosis known to possess different combinations of eight genes were used as sources of template DNA to develop the multiplex PCR protocol, targeting genes for P-fimbriae (papC), aerobactin (iucD), iron-repressible protein (irp2), temperature-sensitive hemagglutinin (tsh), vacuolating autotransporter toxin (vat), enteroaggregative toxin (astA), increased serum survival protein (iss), and colicin V plasmid operon genes (cva/cvi).

Molecular epidemiology of avian pathogenic Escherichia coli (APEC) isolated from colisepticemia in poultry.

The molecular biology and epidemiology of 150 avian pathogenic Escherichia coli strains (APEC) isolated from septicemic poultry in Germany was investigated by serotyping, pulsed field gel electrophoresis (PFGE), and polymerase chain reaction (PCR). Only 49.6% of the isolates could be grouped to serogroups O1, O2, and O78.