Anti-infective bovine colostrum oligosaccharides: Campylobacter jejuni as a case study Jonathan A. Lane a, b , Karina Mariño d , Julie Naughton b , Devon Kavanaugh a , Marguerite Clyne b , Stephen D. Carrington c , Rita M. Hickey a, ⁎ a Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland b UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland c Veterinary Science Centre, University College Dublin, Belfield, Dublin 4, Ireland d National Institute for Bioprocessing Research and Training, Dublin-Oxford Glycobiology Laboratory, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland abstract article info Article history: Received 18 January 2012 Received in revised form 26 April 2012 Accepted 26 April 2012 Available online 12 May 2012 Keywords: Anti-infective activity Bovine colostrum oligosaccharides Campylobacter jejuni Campylobacter jejuni is the leading cause of acute bacterial infectious diarrhea in humans. Unlike in humans, C. jejuni is a commensal within the avian host. Heavily colonized chickens often fail to display intestinal dis- ease, and no cellular attachment or invasion has been demonstrated in-vivo. Recently, researchers have shown that the reason for the attenuation of C. jejuni virulence may be attributed to the presence of chicken intestinal mucus and more specifically chicken mucin. Since mucins are heavily glycosylated molecules this observation would suggest that glycan-based compounds may act as anti-infectives against C. jejuni. Consid- ering this, we have investigated naturally sourced foods for potential anti-infective glycans. Bovine colostrum rich in neutral and acidic oligosaccharides has been identified as a potential source of anti-infective glycans. In this study, we tested oligosaccharides isolated and purified from the colostrum of Holstein Friesian cows for anti-infective activity against a highly invasive strain of C. jejuni. During our initial studies we structurally defined 37 bovine colostrum oligosaccharides (BCO) by HILIC-HPLC coupled with exoglycosidase digests and off-line mass spectroscopy, and demonstrated the ability of C. jejuni to bind to some of these structures, in- vitro. We also examined the effect of BCO on C. jejuni adhesion to, invasion of and translocation of HT-29 cells. BCO dramatically reduced the cellular invasion and translocation of C. jejuni, in a concentration depen- dent manner. Periodate treatment of the BCO prior to inhibition studies resulted in a loss of the anti-infective activity of the glycans suggesting a direct oligosaccharide-bacterial interaction. This was confirmed when the BCO completely prevented C. jejuni binding to chicken intestinal mucin, in-vitro. This study builds a strong case for the inclusion of oligosaccharides sourced from cow's milk in functional foods. However, it is only through further understanding the structure and function of milk oligosaccharides that such compounds can reach their potential as food ingredients. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Campylobacter jejuni is a microaerophilic, Gram-positive, spiral bacterium and a highly invasive enteric pathogen. This adaptive micro- organism is the leading cause of acute bacterial infectious diarrhea in humans and a major burden on the health services in many countries. Common causes of infection include the consumption of contaminated foodstuffs, such as undercooked poultry, and symptoms of infection can range from moderate watery diarrhea to severe dysentery and mesenteric adenitis syndrome mimicking acute appendicitis (Sherman et al., 2010). Complicated cases of infection can result in the emergence of Guillain– Barre syndrome; an immune-mediated radiculopathy arising due to mo- lecular mimicry and antibody cross-reactivity of the lipooligosaccharide antigens of specific bacterial serogroups and gangliosides of neural cells (Sherman et al., 2010). During infection C. jejuni overcomes the harsh gut environment to colonize the gastrointestinal tract (GIT). This is largely due to its motility and corkscrew morphology that enable the invading bacteria to bypass the mechanical and immunological barriers of the GIT. Once ingested the bacterium burrows through the mucous layer and subsequently adheres to and then invades the underlying epithelial cells. These events are essential for the survival of C. jejuni within the human host. Currently, our understanding of the mechanisms involved in these processes remains rudimentary. Thus, it has been extremely dif- ficult to develop therapeutic approaches that protect against Campylobac- ter infection. Recently, the use of food-sourced anti-adhesives to prevent host cell attachment during the early stages of infection has demonstrated some successes. Indeed, this approach has been successful for a number of enteric pathogens including C. jejuni, Helicobacter pylori, Salmonella enteritidis, and Escherichia coli (Ganan et al., 2009, 2010; Mysore et al., International Journal of Food Microbiology 157 (2012) 182–188 ⁎ Corresponding author. Tel.: + 353 25 42227; fax: + 353 25 42340. E-mail address: rita.hickey@teagasc.ie (R.M. Hickey). 0168-1605/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2012.04.027 Contents lists available at SciVerse ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro