Reduction of caecal Listeria monocytogenes in Leghorn chicks following treatment with a competitive exclusion culture (PREEMPT)
Day-of-hatch Leghorn chicks were treated by oral gavage with PREEMPT, a continuous-flow competitive exclusion culture containing broiler caecal bacteria, followed by an oral challenge with Listeria monocytogenes, to determine the effects of PREEMPT on L. monocytogenes caecal colonization. Increased (P < 0.001) concentrations of caecal propionic acid in control chicks compared with PREEMPT-treated chicks at 3 days of age were indicative of the establishment of the PREEMPT bacteria. Caeca from control chicks at 7 days after the oral challenge with L. monocytogenes contained mean 3.4 +/- 1.4 log cfu g-1 of caecal content, while caeca from PREEMPT-treated chicks contained no detectable Listeria. Enrichment for L. monocytogenes resulted in 100% of caeca from control chicks testing culture-positive for L. monocytogenes, while none of the caeca from PREEMPT-treated chicks were culture-positive. The results indicated that prophylactic treatment of newly hatched chicks with PREEMPT significantly reduced caecal colonization by L. monocytogenes.
Hume
M E
ME
USDA, Agricultural Research Service, College Station, TX, USA.
Byrd
J A
JA
Stanker
L H
LH
Ziprin
R L
RL
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000890:Anti-Infective Agents; D002432:Cecum / Q000382:microbiology*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D005516:Food Microbiology; D008089:Listeria monocytogenes / Q000254:growth & development; D008088:Listeriosis / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D009930:Organic Chemicals; D011201:Poultry Diseases / Q000382:microbiology / Q000517:prevention & control*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D009930:Organic Chemicals; C112898:preempt