Cox, Eric

De Zutter, Lieven

Kieckens, Evelien

Remon, Jean Paul

Rybarczyk, Joanna

Vanrompay, Daisy

English

Ghent University Academic Bibliography

    Clearance of Escherichia coli O157:H7 infection in calves by rectal administration of bovine lactoferrin. Rybarczyk J.a, Kieckens E.a, De Zutter L.b, Remon JP.c,  Vanrompay D.d, Cox E.a a Laboratory of Immunology; b Veterinary Public Health and Safety; c Laboratory of Pharmaceutical Technology, d Laboratory of Immunology and Animal Biotechnology, Ghent University.                                         Number of E. coli O157:H7 per gram intestinal content Lactoferrin treatment jejunum ileum caecum colon rectum Rectal treatment 0* 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Control 0 0 0 0 1,00E+01 0 0 0 0 0 1,00E+02 6,00E+02 0 0 1,00E+02 Oral treatment 0 0 0 0 1,00E+01 0 0 0 0 0 0 0 2,00E+03 1,10E+03 3,00E+02  Number of E. coli O157:H7 on tissue Lactoferrin treatment jejunum PP** jejunum ileum PP ileum colon recto-anal junction Rectal treatment 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Control 0 0 0 0 0 0 0 0 0 0 0 1,00E+02 0 0 0 0 0 0 Oral treatment 0 0 0 4,00E+02 0 0 0 0 0 0 0 0 0 0 0 3,00E+02 0 1,00E+02                         Enterohemorrhagic Escherichia coli (EHEC) is a major food-borne pathogen causing severe disease in humans worldwide. The main reservoirs of EHEC are ruminants, mostly cattle, which harbour the bacteria in the gastrointestinal tract without causing apparent illness. Nowadays, the specific mechanisms responsible for the persistence         of EHEC in ruminants are unknown and there is no effective strategy available to combat this pathogen. In this study, the treatment of EHEC infected calves with lactoferrin (LF) was investigated  as a possible future strategy for reducing shedding of EHEC by ruminants.     Nine calves were orally inoculated at the age of 12 weeks and                  re-inoculated 7 days later with 1010 CFU E. coli (strain NCTC12900) for      2 consecutive days. On day 4, 3 calves  were orally administered 3 g lactoferrin per day  for  51 days ( oral treatment group) and  3 calves were rectally treated with 300 mg lactoferrin per day for 33 days ( rectal treatment group). 3 calves served as controls and were sham-treated with PBS orally. Faecal excretion was monitored 2 times a week by direct plating and an enrichment. To determine the presence of bacteria in the intestinal tract after LF treatment, intestinal contents and tissues (jejunum, ileum, caecum, colon and rectum) were collected from all animals at euthanasia and were immediately tested by direct plating.   Magnitude and duration of faecal O157:H7 shedding (Fig.1) was similar for the oral treatment group and the control group. Animals in both groups were excreting bacteria in the faeces during at least 54 days. In contrast, rectal administration of LF induced  a reduction  in faecal E. coli O157:H7 excretion from day 4 onwards. The shedding pattern of the rectal treatment group and the control group was significantly different from days 19 to 22 and days 33 to 36 (p ≤ 0.05). On day 12, two animals from the rectal treatment group already ceased excreting E. coli O157:H7. Both stayed negative till the end of the experiment (day 36) without further LF administration, even though the other animal in this group remained positive by direct enumeration until day 26. Faecal contents and tissues of the rectal treated group contained no bacteria, suggesting that rectal LF treatment completely eliminated the E. coli O157:H7 infection.      INTRODUCTION RESULTS MATERIALS AND METHODS Rectal administration of lactoferrin reduced E. coli O157:H7 shedding. Moreover, administration of this antimicrobial protein resulted in clearance of rectal colonization. Lactoferrin could be an interesting tool to reduce the number of cattle excreting E. coli O157:H7 and could thereby reduce the zoonotic risk for humans.     CONCLUSIONS  *<10 colonies per gram, **pp = Peyer’s patches;   Fig.1 Average E. coli O157:H7 excretion following infection, oral and rectal             LF treatment of calves. x   Significant differences in bacteria excretion between control and rectal treatment groups, +  Significant differences in bacteria excretion between  oral and rectal treatment  groups, † Euthanasia.  † † 

Clearance of Escherichia coli O157:H7 infection in calves by rectal administration of bovine lactoferrin

https://biblio.ugent.be/publication/4146707/file/4146725

Clearance of Escherichia coli O157:H7 infection in calves by rectal administration of bovine lactoferrin

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