TABLE 1.

Summary of key studies investigating biofilm formation by C. jejuni under different conditions

Study	Analysis of biofilm	Aerobic or microaerobic	Incubation temp (°C)	Mono-/multispecies	Static or flow conditions	No. of strains used	Main result(s)
Joshua et al. (4)	Observation of aggregates, pellicles, or attached biofilms on abiotic surfaces	Microaerobic	37	Monospecies	Static, shaking, and flow conditions	17	Three distinct biofilms formed by C. jejuni (attached, flocs, pellicles)
	SEM-CLSM analysis of biofilms formed on glass						C. jejuni unable to form biofilms under shaking and flow conditions
Kalmokoff et al. (19)	SEM analysis of biofilm structures on nitrocellulose membranes, stainless steel, and glass fiber filters	Microaerobic	37	Monospecies	Static	1 (C. jejuni NCTC11168)	Multicellular layers consisting of EPM formed by C. jejuni, representing a mature biofilm
Asakura et al. (34)	Attachment on 24-well polystyrene plates and quantified by crystal violet staining	Aerobic and microaerobic	37	Monospecies	Static	1 (C. jejuni NCTC11168)	C. jejuni biofilm formation higher under aerobic than microaerobic conditions
Reeser et al. (31)	Attachment on 24-well polystyrene plates, quantified by crystal violet staining	Aerobic and microaerobic	37/25	Monospecies	Static	1 (C. jejuni M129)	Biofilm formation enhanced under conditions favoring growth (microaerophilic, 37°C)
							Biofilm formation inhibited by nutrient-rich media/high osmolarity
	Attachment on abiotic surfaces, quantified by cell enumeration	Microaerobic	37	Monospecies	Static	1 (C. jejuni M129)	C. jejuni can attach to hydrophobic and hydrophilic surfaces, with more biofilm formed on latter
Sanders et al. (32)	CLSM analysis of biofilms on stainless steel	Aerobic	37	Multispecies	Static	1 (C. jejuni RM1221)	C. jejuni formed biofilms on stainless steel when incubated with mixed bacterial populations
Hanning et al. (25)	Attachment to mixed-species preestablished biofilms on stainless steel chips, quantified by cell enumeration	Aerobic	10/23/32	Multispecies	Static	1 (C. jejuni 43431)	Preestablished biofilms facilitate C. jejuni attachment to surfaces
Gunther and Chen (26)	Attachment on abiotic surfaces, quantified by crystal violet staining	Microaerobic	42	Monospecies	Static	2 strains (C. jejuni 81-176 and RM1221)	Biofilm formation different for different strains
	SEM analysis of biofilms formed on glass
Reuter et al. (35)	Attachment on glass test tubes, quantified by crystal violet and Congo red staining	Aerobic and microaerobic	37	Monospecies	Static	1 (C. jejuni NCTC11168)	C. jejuni biofilm formation higher under aerobic than microaerobic conditions
	Light microscopy analysis of biofilms formed on glass
Teh et al. (36)	Attachment on 24-well polystyrene plates, quantified by crystal violet staining	Microaerobic	37	Mono- and multispecies	Static (gentle swirling)	20	C. jejuni can form mixed-species biofilms
Ica et al. (39)	Biofilm structures quantified by microscopy	Aerobic	25/37	Mono- and multispecies	Flow	1 (C. jejuni NCTC11168)	Monoculture C. jejuni biofilms unable to persist at higher flow rates
							Mixed-culture biofilms more stable and robust than monoculture biofilms