HomePhilippine Journal of Veterinary Medicinevol. 47 no. 1 (2010)

Fecal Shedding, Organ Distribution and Observed Pathological Changes Over a 150-hour Period in BALB/c Mice Orally-infected with Locally Isolated Salmonella Species

Marla F. Caraballe | Mary Joy N. Gordoncillo | Loinda R. Baldrias | Teresita J. Ramirez | Joseph S. Masangkay

Discipline: Veterinary Medicine

 

Abstract:

This study investigated the earliest shedding time, systemic spread and pathological damage produced by Salmonella spp. after oral infection of mice. Polymerase chain reaction and conventional bacterial isolation were performed using fecal and organ samples collected at specified time intervals. BALB/c mice were orally infected with 0.5 ml of 103 CFU Salmonella spp. in broth. Preenrichment of samples was done using both tetrathionate and brain heart infusion (BHI) broths. Samples incubated in tetrathionate broth were subjected to conventional tube biochemical testing for characterization of Salmonella spp. isolates, while those incubated in BHI were used for DNA extraction and molecular detection using lhe DAS™ Salmonella kit of BIOTECH, UPLB. Salmonella spp. were shed at 2 h post infection (pi) and last isolated at 84 h post infection from the droppings. Salmonella was present in the lymph node at 2 h pi, in the liver, spleen, kidney, heart and small intestines at both 12 and 18 h pi. Sloughing of the microvilli, edema and lymphocytic infiltration in the enterocytes of the intestines were observed. Tubular atrophy progressing to glomerulopathy was evident in the kidney. There was also cloudy swelling and fatty degeneration in the liver and lymphocytic hyperplasia in the spleen