Virulence-associated genes in Escherichia coli isolates from poultry with colibacillosis

Delicato, Elaine R.; Brito, Benito Guimarães de; Gaziri, L. C. J.; Vidotto, Marilda Carlos

doi:10.1016/s0378-1135(03)00076-2

Cited by 146 publications

(145 citation statements)

References 17 publications

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“…Challenge studies indicated a significant reduction of the virulence of the ibeA mutant. Based on prevalence studies and virulence attenuation of a mutant, conclusions have been drawn for several of the virulence genes identified to date for APEC strains (Blanco et al, 1997;Delicato et al, 2003;Dozois et al, 1992Dozois et al, , 2000Parreira & Gyles, 2003). It is therefore reasonable to assume that ibeA, when present, plays a role in the pathogenicity of APEC strains.…”

Section: Discussionmentioning

confidence: 99%

“…Another gene whose precise function remains to be elucidated is the iss gene (Binns et al, 1979); this gene is presumed to play a role in serum resistance but, if so, its role seems to be minor (Mellata et al, 2003a). Different associations of virulence genes have been detected and could reflect the existence of different pathotypes (Delicato et al, 2003). Indeed, not a single virulence gene is found in any of the APEC strains that is absent from all non-pathogenic strains.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, not a single virulence gene is found in any of the APEC strains that is absent from all non-pathogenic strains. This might indicate the use of different virulence mechanisms by different putative pathotypes (Delicato et al, 2003;La Ragione & Woodward, 2002). …”

Section: Introductionmentioning

confidence: 99%

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ibeA, a virulence factor of avian pathogenic Escherichia coli

et al. 2005

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The presence of ibeA, a gene encoding a known virulence factor of Escherichia coli strains responsible for neonatal meningitis in humans, was investigated in the genome of 213 avian pathogenic E. coli (APEC) strains and 55 non-pathogenic E. coli strains of avian origin. Fifty-three strains were found to be ibeA + , all of which belonged to the APEC group. The ibeA gene is therefore positively linked to the pathogenicity of strains (P<0?0001). Analysis of the serogroup of strains revealed a positive association of ibeA with serogroups O18, O88 and O2. On the contrary, only 1/59 O78 strains are ibeA + , indicating a negative association of ibeA with this serogroup (P<0?0001). The role of ibeA in the virulence of the APEC strain BEN 2908 was investigated by constructing an ibeA mutant. Challenge assays on 3-week-old chickens showed a reduced virulence for the ibeA mutant. Furthermore, the APEC strain BEN 2908 was able to invade brain microvascular epithelial cells, this invasion being significantly reduced upon inactivation of ibeA. Altogether, these results suggest a role of ibeA in the pathogenicity of some APEC strains and confirm the close relationship between APEC and other human extraintestinal pathogenic E. coli isolates.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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ibeA, a virulence factor of avian pathogenic Escherichia coli

et al. 2005

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“…Although Escherichia coli are likely widespread in the normal gastrointestinal flora and production environment of poultry, it is thought that only specific E. coli strains are endowed with virulence factors, enabling them to cause disease [8]. The disease they cause, avian colibacillosis, is extraintestinal in nature, manifesting in various ways, including as air sacculitis, cellulitis, and septicemia [2].…”

Section: Introductionmentioning

confidence: 99%

“…Although several virulence traits have been associated with the E. coli causing disease in birds [2], an avian pathogenic E. coli (APEC) pathotype remains ill-defined [8].…”

Section: Introductionmentioning

confidence: 99%

Characterizing the APEC pathotype

et al. 2005

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-The purpose of this study was to compare avian pathogenic Escherichia coli (APEC) isolates to fecal isolates of apparently healthy poultry (avian fecal E. coli or AFEC) by their possession of various traits in order to ascertain whether APEC and AFEC are distinct and if the APEC strains constitute a distinct pathotype. Four hundred and fifty-one APEC and one hundred and four AFEC isolates were examined for possession of traits associated with the virulence of human extraintestinal pathogenic E. coli (ExPEC) as well as APEC. Several of the genes occurred in the majority of APEC and only infrequently in AFEC, including cvaC, iroN, iss, iutA, sitA, tsh, fyuA, irp2, and ompT. Of these genes, several have been found on large plasmids in APEC. Other genes occurred in significantly more APEC than AFEC but did not occur in the majority of APEC. Isolates were also evaluated by serogroup, lactose utilization, and hemolytic reaction. Twenty-nine and a half percent of the APEC and forty-two and three tenths percent of the AFEC were not serogrouped because they were not typeable with standard antisera, typed to multiple serogroups, were rough, autoagglutinated, or were not done. Around 65% of the typeable APEC (205 isolates) and AFEC (41 isolates) were classified into shared serogroups, and about a third of both fell into APEC-(113 isolates) or AFEC-(19 isolates) unique serogroups. Most were able to use lactose. No isolate was hemolytic. Overall, the majority of the APEC isolates surveyed shared a common set of putative virulence genes, many of which have been localized to an APEC plasmid known as pTJ100. This common set of genes may prove useful in defining an APEC pathotype. avian pathogenic Escherichia coli (APEC) / pathotype / virulence plasmid / ExPEC / pTJ100

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