A Mixture of Lactobacillus casei, Lactobacillus lactis, and Paenibacillus polymyxa Reduces Escherichia coli O157:H7 in Finishing Feedlot Cattle

• Published in: Journal of food protection 2014-05, Vol.77 (5), p.738-744
• Main Authors: STANFORD, Kim, BACH, Susan, BAAH, John, MCALLISTER, Tim
• Format: Article
• Language: English
• Subjects: Acids; Animal Feed - analysis; Animal Feed - microbiology; Animals; Antimicrobial agents; Barley; Biological and medical sciences; Cattle; Cattle Diseases - microbiology; Cattle Diseases - prevention & control; Colony Count, Microbial; Dry matter; E coli; Electrophoresis; Escherichia coli; Escherichia coli Infections - microbiology; Escherichia coli Infections - prevention & control; Escherichia coli Infections - veterinary; Escherichia coli O157 - classification; Escherichia coli O157 - isolation & purification; Escherichia coli O157 - physiology; Feces; Feces - microbiology; Feeds; Female; Food industries; Food safety; Fundamental and applied biological sciences. Psychology; Lacticaseibacillus casei - physiology; Lactobacillus - physiology; Lactobacillus casei; Lactobacillus lactis; Male; Microorganisms; Organisms; Paenibacillus - physiology; Paenibacillus polymyxa; Pathogens; Probiotics - administration & dosage; Public health
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X.JFP-13-433

A direct-fed microbial (DFM) containing Paenibacillus polymyxa, Lactobacillus casei, and Lactobacillus lactis was fed to cattle (n = 120) to determine impacts on shedding and survival of Escherichia coli O157:H7 in feces. Cattle were individually penned and fed diets containing 0 (control), 4 × 10(7) CFU (DFM-4), 8 × 10(7) CFU (DFM-8), or 1.2 × 10(8) CFU (DFM-12) lactobacilli per kg of dietary dry matter over 84-day fall-winter growing and 140-day spring-summer finishing periods. Fecal grab samples were collected from cattle at 28-day intervals, E. coli O157:H7 was detected by immunomagnetic separation, and isolates were compared by pulsed-field gel electrophoresis. During the growing period, feces negative for E. coli O157 from each dietary treatment were inoculated with 10(5) CFU/g nalidixic acid-resistant E. coli O157:H7 and were incubated at 4 and 22(u) C for 11 weeks. Fecal pH and fecal dry matter were measured on days 0, 1, 3, and 7 and weekly thereafter, with E. coli O157:H7 enumerated through dilution plating. Treatment with DFMs did not affect survival of E. coli O157:H7 in feces or fecal pH (P > 0.05). Only one steer was positive for E. coli O157:H7 during the growing period, but during the finishing period, DFM-8 and DFM-12 reduced the prevalence of E. coli O157:H7 in feces (P < 0.05). Feeding DFMs also reduced the frequency of individual steers shedding E. coli O157:H7 during finishing (P < 0.05), with control steers shedding E. coli O157:H7 up to four times, whereas DFM-12 steers shed E. coli O157:H7 a maximum of twice. Treatment with DFMs influenced pulsed-field gel electrophoresis profiles; steers that were fed DFM-8 and DFM-12 shed more diverse subtypes of E. coli O157:H7 than did control or DFM-4 steers. Because a companion study found linear improvement in performance with increasing dosage of DFMs in the first 28 days of the growing period, targeted use of DFM-12 during this time and for the final 1 or 2 weeks prior to slaughter may optimize performance and reduce E. coli O157:H7 while minimizing feed costs.