Current Research on Campylobacter Biofilms

Compared to many other food-borne pathogens, such as Escherichia coli and Salmonella enterica, Campylobacter is more fastidious in its growth requirements. Specifically, it requires a reduced oxygen atmosphere (5% oxygen, 10% carbon dioxide, and 85% nitrogen) to grow. C. jejuni grows between the lower and upper limits of 30 °C and 42 °C, respectively, and can survive at temperatures below 8 °C.  The bacterium is susceptible to various environmental and food processing-induced stressors, such as dry conditions, osmotic stress, temperatures between 8 °C and 30 °C, and pH. [1] This would make C. jejuni unsuitable for survival outside the host in natural aerobic environments or in the food chain. In reality, however, C. jejuni is widely spread in the environment and can be readily isolated from food, water, and other sources.[2] Recent findings from the FSA reported that viable cultures of C. jejuni could be recovered from the external surfaces of a small percentage chicken packages.[3] Research reports have suggested that biofilm formation has a key-role in survival of C. jejuni in the environment and the food chain.[4]


Figure 3  Growth of Campylobacter jejuni NCIMB 50091 on (A) sheep blood nutrient agar (B) Campylobacter blood free agar (C) Campylobacter blood free agar as a concentrated cell suspension forming mostly distinct colonies and (D) Campylobacter blood free agar as a diluted cell suspension forming amorphous colonies. 


Figure 4 Histogram of publications on "Campylobacter Biofilms", per year of publication, provided by the Reaxys database

There have been an increasing number of studies investigating C. jejuni biofilms in recent years, albeit the total numbers of studies are still relatively low. The Figure 4 shows the growing number of peer reviewed papers abstracted in the Reaxys database on the topic. Similarly to other foodborne bacteria, C. jejuni forms biofilms on abiotic surfaces, such as stainless steel and plastic surfaces.[5,6,7] Such surfaces would be typically found in slaughter houses [8] or in poultry house water systems, [9] and will be a factor in the persistent survival of C. jejuni as it continues to survive outside the host under unfavourable conditions. Aerobic conditions are one particular example which is an unfavourable condition for Campylobacter, which encourages biofilm formation. [10] These are characteristic of outer packaging where Campylobacter is currently found in supermarkets. Reeser et al, [11] showed that C. jejuni attached to form a good biofilm on plastic hydrophobic surfaces commonly found in watering systems or wet packaging materials. Dykes et al. [12] found that C. jejuni grown as planktonic cells and as biofilm cells survived longer at lower temperatures (4°C and 10°C), typical of cold-meat storage, than at higher temperatures (25°C and 37°C) under stress conditions. [13]  Ultimately published work showed that Campylobacter biofilms are formed in the chicken exudate and at the interface chicken exudate-packaging. [14]

These biofilms will act as a source of contamination and contribute to the high number of human C. jejuni infections. As such a clear understanding of how, and to what extent, C. jejuni biofilms on abiotic surfaces could be destabilised is important in order to develop strategies to prevent the contamination of food products by these bacteria on food processing surfaces. Biofilms can consist of single or multiple microbial species, but in nature mixed-species biofilms predominate in most environments. [15] Previous studies have shown that C. jejuni is a poor biofilm initiator and monospecies C. jejuni biofilms form only under specific growth conditions. [16] Balaguram et al. [17 ] reported that Campylobacter would survive better in the presence of other meat microflora.  The current paradigm requiring more research, suggests that under conditions that inhibit its growth, C. jejuni is able to survive by forming mixed biofilms with other bacterial species. [18]

  1. Keener KM, Bashor MP, Curtis PA, Sheldon BW, Kathariou S. 2004. Comprehensive review of Campylobacter and poultry processing. Compr. Rev. Food Sci. Food Saf.
  2. Murphy C, Carroll C, Jordan K. 2006. Environmental survival mechanisms of the foodborne pathogen Campylobacter jejuni. J. Appl. Microbiol.
  3. http://www.telegraph.co.uk/news/health/11249235/Campylobacter-keep-chicken-in-separate-bag-in-fridge-shoppers-told.html
  4. Kalmokoff M, Lanthier P, Tremblay T-L, Foss M, Lau PC, Sanders G, Austin J, Kelly J, Szymanski CM. 2006. Proteomic analysis of Campylobacter jejuni 11168 biofilms reveals a role for the motility complex in biofilm formation. J. Bacteriol. 188:4312–4320.
  5. Asakura H, Yamasaki M, Yamamoto S, Igimi S. 2007. Deletion of peb4 gene impairs cell adhesion and biofilm formation in Campylobacter jejuni. FEMS Microbiol. Lett. 275:278–285.
  6. Fields JA, Thompson SA. 2008. Campylobacter jejuni CsrA mediates oxidative stress responses, biofilm formation, and host cell invasion. J. Bacteriol. 190:3411–3416. 
  7.  Dykes G, Sampathkumar B, Korber D. 2003. Planktonic or biofilm growth affects survival, hydrophobicity and protein expression patterns of a pathogenic Campylobacter jejuni strain. Int. J. Food Microbiol. 89:1–10. 10.1016/S0168-1605(03)00123-5 
  8. Moe KK, Mimura J, Ohnishi T, Wake T, Yamazaki W, Nakai M, Misawa N.
    The mode of biofilm formation on smooth surfaces by Campylobacter jejuni.
    J Vet Med Sci. 2010 Apr;72(4):411-6. Epub 2009 Dec 10.
  9. Trachoo N, Frank JF, Stern NJ. Survival of Campylobacter jejuni in biofilms isolated from chicken houses, J Food Prot. 2002
  10. Reuter M, Mallett A, Pearson BM, van Vliet AH. Biofilm formation by Campylobacter jejuni is increased under aerobic conditions. Appl Environ Microbiol. 2010 Apr;76(7):2122-8.
  11. Reeser RJ, Medler RT, Billington SJ, Jost BH, Joens LA. 2007. Characterization of Campylobacter jejuni biofilms under defined growth conditions. Appl. Environ. Microbiol. 73:1908–1913. 
  12. Dykes G, Sampathkumar B, Korber D. 2003. Planktonic or biofilm growth affects survival, hydrophobicity and protein expression patterns of a pathogenic Campylobacter jejuni strain. Int. J. Food Microbiol. 89:1–10.
  13. Kumar CG, Anand S. 1998. Significance of microbial biofilms in food industry: a review. Int. J. Food Microbiol. 42:9–27.
  14. Brown HL, Reuter M, Salt LJ, Cross KL, Betts RP, van Vliet AH3.Chicken juice enhances surface attachment and biofilm formation of Campylobacter jejuni, Appl Environ Microbiol. 2014 Nov;80(22):7053-60.
  15. O'Toole G, Kaplan HB, Kolter R. 2000. Biofilm formation as microbial develop. Annu. Rev. Microbiol. 54:49–79.
  16. Sanders SQ, Boothe DH, Frank JF, Arnold JW. 2007. Culture and detection of Campylobacter jejuni within mixed microbial populations of biofilms on stainless steel. J. Food Prot. 70:1379–1385
  17. Balamurugan et al, Survival of Campylobacter jejuni on beef and pork under vacuum packaged and retail storage conditions: examination of the role of natural meat microflora on C. jejuni survival. Food Microbiol. 2011 Aug;28(5):1003-10.
  18. Hanning I, Jarquin R, Slavik M. 2008. Campylobacter jejuni as a secondary colonizer of poultry biofilms. J. Appl. Microbiol. 105:1199–1208.