TY - JOUR
T1 - Investigation of the effects of ph and bile on the growth of oral Campylobacter concisus strains isolated from patients with inflammatory bowel disease and controls
AU - Ma, Rena
AU - Sapwell, Nicholas
AU - Chung, Heung Kit Leslie
AU - Lee, Hoyul
AU - Mahendran, Vikneswari
AU - Leong, Rupert W.
AU - Riordan, Stephen M.
AU - Grimm, Michael C.
AU - Zhang, Li
PY - 2015/4
Y1 - 2015/4
N2 - Campylobacter concisus is an oral bacterium that is associated with inflammatory bowel disease (IBD). This study examined the impact of pH and bile on the growth of oral C. concisus strains isolated from patients with IBD and controls. The growth of 58 C. concisus strains on horse blood agar (HBA) plates following exposure to media with various pH values for different time points was examined. Furthermore, the growth of C. concisus strains on HBA plates containing different concentrations of ox bile was investigated. Following exposure to pH 2 for 30 min, none of the 58 oral C. concisus strains grew on HBA plates. Following exposure to pH 3.5 for 30 min, only four of 20 oral strains examined grew on HBA plates, with a log10 c.f.u. reduction of 0.7–2.5 compared to the same strains without low pH exposure. Exposure to pH 5 for 120 min had minimal effects on C. concisus growth. Approximately half of the oral strains (55.2%, 32/58) grew on HBA containing 2% bile. Bile inhibited the growth of C. concisus in a dose- and straindependent manner. These data suggest that both bacterial and intestinal environmental factors may play a role in the determination of C. concisus colonization in the different parts of the gastrointestinal tract and that increased gastric pH and reduced intestinal bile may be risk factors for increased gastric and intestinal C. concisus colonization.
AB - Campylobacter concisus is an oral bacterium that is associated with inflammatory bowel disease (IBD). This study examined the impact of pH and bile on the growth of oral C. concisus strains isolated from patients with IBD and controls. The growth of 58 C. concisus strains on horse blood agar (HBA) plates following exposure to media with various pH values for different time points was examined. Furthermore, the growth of C. concisus strains on HBA plates containing different concentrations of ox bile was investigated. Following exposure to pH 2 for 30 min, none of the 58 oral C. concisus strains grew on HBA plates. Following exposure to pH 3.5 for 30 min, only four of 20 oral strains examined grew on HBA plates, with a log10 c.f.u. reduction of 0.7–2.5 compared to the same strains without low pH exposure. Exposure to pH 5 for 120 min had minimal effects on C. concisus growth. Approximately half of the oral strains (55.2%, 32/58) grew on HBA containing 2% bile. Bile inhibited the growth of C. concisus in a dose- and straindependent manner. These data suggest that both bacterial and intestinal environmental factors may play a role in the determination of C. concisus colonization in the different parts of the gastrointestinal tract and that increased gastric pH and reduced intestinal bile may be risk factors for increased gastric and intestinal C. concisus colonization.
UR - http://www.scopus.com/inward/record.url?scp=84927758878&partnerID=8YFLogxK
U2 - 10.1099/jmm.0.000013
DO - 10.1099/jmm.0.000013
M3 - Article
C2 - 25657299
AN - SCOPUS:84927758878
SN - 0022-2615
VL - 64
SP - 438
EP - 445
JO - Journal of Medical Microbiology
JF - Journal of Medical Microbiology
IS - 4
ER -