Characteristics of selected <i>Escherichia coli</i> isolates from chicken fecal samples used for <i>in vivo</i> experiments.

<p>Characteristics of selected <i>Escherichia coli</i> isolates from chicken fecal samples used for <i>in vivo</i> experiments.</p

Ability of fecal <i>Escherichia coli</i> isolates to urinary tract infection.

<p><i>E</i>. <i>coli</i> isolates MM242, MM243, MM244, MM248, and MM259, positive controls CFT073 and UTI89, and negative control MG1655 were assessed for their ability to colonize the (A) bladder and (B) kidney, and to invade in the (C) liver and (D) spleen of CBA/J mice. Mice were challenged with 10⁸ CFU via a urethral catheter and monitored for 2 days. Each experimental group contained at least 9 mice. Each dot represents an individual animal; the vertical dashed line separates chicken fecal <i>E</i>. <i>coli</i> isolates from control strains. An asterisk (*) represents significantly higher mean values determined by an ANOVA followed by Dunnett’s method for fecal <i>E</i>. <i>coli</i> isolates and positive control strains compared with the negative control.</p

Prevalence of virulence-associated <i>in vitro</i> phenotypes among chicken fecal <i>Escherichia coli</i> isolates.

<p>Prevalence of virulence-associated <i>in vitro</i> phenotypes among chicken fecal <i>Escherichia coli</i> isolates.</p

Ability of fecal <i>Escherichia coli</i> isolates to cause lethal sepsis in mice.

<p>A BALB/c mouse sepsis model was used to evaluate the ability of <i>E</i>. <i>coli</i> isolates to cause lethal sepsis within 7 days of intraperitoneal challenge with 10⁸ CFU. Five mice were used per strain. (A) Severity scores, as recorded over the week using a 5-point scoring scheme (1, healthy; 2, minimally ill; 3, moderately ill; 4, severely ill; 5, dead). (B) Survival rate over 7 d. Human ExPEC isolate CFT073 was used as a positive control and <i>E</i>. <i>coli</i> K-12 MG1655 as a negative control. An asterisk (*) represents a significantly (<i>P</i> < 0.05) different survival curve determined by The Log-rank (Mantel-Cox) test for experimental isolates or positive control strain CFT073 compared with the negative control MG1655.</p