ERE-PC-1201

FUMUSO E.; HERRERA M.; ROSSATI J.; QUINTEROS D.; ESTEIN S.M.; CERIANI C.

2012-01-01

2012-06-01

Sanidad animal-Enfer. infec. bacterianas

The purpose of this study was to test and compare pathogenicity of two preparations new and old, of the same R. equi challenge strain R.equi 103+.This experimental study included 19 foals, distributed in 5 experimental groups. Foals were born at the University and non foals or mares were previously vaccinated with R equi bacterin and they came from non endemic farms. These foals were randomly assigned into each group and challengeintrabroncheal inoculation of virulent R. equi (at an appropriate concentration) in one bronchus using a fiberoptic bronchoscope (foals required sedation in order to pass the fiberoptic)with 25ml of PBS containing 10to5, 10to6 10to7 cfu per foal. To determine the infective disease in foals, clinical observations (rectal temperature, respiratory frequency, heart rate) and complementary studies like laboratory fibrinogen levels analysis and thorax ultrasonography. Illness criteria: The criteria for ultrasound interpretation are multiple little abscesses or one abscess higher than 2.5 cm correlated with, fiber, fibrinogen or clinical signs means illness signs. Foals that presented from light to severe fever augment of respiratory or heart frequency, levels of fibrinogen up to 400 and lung abscess were considered sick. At this moment a bronchotracheal lavage was performed, the disease confirmation was performed by bacteriological culture, PCR and X Rays. Only 5/19 foals reached the sickness criteria, throw the study. Although some Foals were challenged later than the day 42 after birth, they got sick.