Limits...
On Lactococcus lactis UL719 competitivity and nisin (Nisaplin(®)) capacity to inhibit Clostridium difficile in a model of human colon.

Le Lay C, Fernandez B, Hammami R, Ouellette M, Fliss I - Front Microbiol (2015)

Bottom Line: Bacterial populations was enumerated by qPCR coupled to PMA treatment.L. lactis UL719 was able to survive and proliferate under simulated human colon, did not alter microbiota composition, but failed to inhibit C. difficile.While a single dose of 19 μmol/L (5× the MIC) was not sufficient to inhibit C. difficile, nisin at 76 μmol/L (20×the MIC) was effective at killing the pathogen.

View Article: PubMed Central - PubMed

Affiliation: STELA Dairy Research Center, Nutrition and Functional Foods Institute, Université Laval, Québec QC, Canada ; Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec, Québec QC, Canada ; Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec QC, Canada.

ABSTRACT
Clostridium difficile is the most frequently identified enteric pathogen in patients with nosocomially acquired, antibiotic-associated diarrhea and pseudomembranous colitis. Although metronidazole and vancomycin were effective, an increasing number of treatment failures and recurrence of C. difficile infection are being reported. Use of probiotics, particularly metabolically active lactic acid bacteria, was recently proposed as an alternative for the medical community. The aim of this study was to assess a probiotic candidate, nisin Z-producer Lactococcus lactis UL719, competitivity and nisin (Nisaplin(®)) capacity to inhibit C. difficile in a model of human colon. Bacterial populations was enumerated by qPCR coupled to PMA treatment. L. lactis UL719 was able to survive and proliferate under simulated human colon, did not alter microbiota composition, but failed to inhibit C. difficile. While a single dose of 19 μmol/L (5× the MIC) was not sufficient to inhibit C. difficile, nisin at 76 μmol/L (20×the MIC) was effective at killing the pathogen. Nisin (at 76 μmol/L) caused some temporary changes in the microbiota with Gram-positive bacteria being the mostly affected. These results highlight the capacity of L. lactis UL719 to survive under simulated human colon and the efficacy of nisin as an alternative in the treatment of C. difficile infections.

No MeSH data available.


Related in: MedlinePlus

Survival of L. lactis UL719 after its last addition (day 62) in a human colon model.L. lactis UL719 (circle); theoretical washout (square).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4585240&req=5

Figure 2: Survival of L. lactis UL719 after its last addition (day 62) in a human colon model.L. lactis UL719 (circle); theoretical washout (square).

Mentions: After the stabilization period, L. lactis UL719, C. difficile ATCC43255, and their combination were successively added to the bioreactor and the microbiota populations were monitored by qPCR (Table 3). Interestingly, the addition of L. lactis UL719 at 1 × 109 CFU/mL to the bioreactor, did not induce any significant change neither in the intestinal microbiota composition nor in metabolites production (Table 4). Since the last addition of L. lactis UL719 to the reactor, the strain was detected at about 0.1 - 1 × 109 CFU/mL during the remaining 20 days of fermentation (Figure 2). While the infection of the bioreactor with 5 × 106 CFU/mL of C. difficile did not affect the microbiota composition, a slight but significant decrease (p < 0.05) of acetate and butyrate was detected (from 76.24 to 72.59 mmol/L and from 32.13 to 29.54 mmol/L, respectively) (Table 4). Simultaneous addition of C. difficile and L. lactis UL719 had no impact on the microbiota cell counts but a significant decrease (p < 0.05) of butyrate (from 32.13 to 28.40 mmol/L). Under these conditions, L. lactis has no inhibitory effect on C. difficile (Figure 3).


On Lactococcus lactis UL719 competitivity and nisin (Nisaplin(®)) capacity to inhibit Clostridium difficile in a model of human colon.

Le Lay C, Fernandez B, Hammami R, Ouellette M, Fliss I - Front Microbiol (2015)

Survival of L. lactis UL719 after its last addition (day 62) in a human colon model.L. lactis UL719 (circle); theoretical washout (square).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585240&req=5

Figure 2: Survival of L. lactis UL719 after its last addition (day 62) in a human colon model.L. lactis UL719 (circle); theoretical washout (square).
Mentions: After the stabilization period, L. lactis UL719, C. difficile ATCC43255, and their combination were successively added to the bioreactor and the microbiota populations were monitored by qPCR (Table 3). Interestingly, the addition of L. lactis UL719 at 1 × 109 CFU/mL to the bioreactor, did not induce any significant change neither in the intestinal microbiota composition nor in metabolites production (Table 4). Since the last addition of L. lactis UL719 to the reactor, the strain was detected at about 0.1 - 1 × 109 CFU/mL during the remaining 20 days of fermentation (Figure 2). While the infection of the bioreactor with 5 × 106 CFU/mL of C. difficile did not affect the microbiota composition, a slight but significant decrease (p < 0.05) of acetate and butyrate was detected (from 76.24 to 72.59 mmol/L and from 32.13 to 29.54 mmol/L, respectively) (Table 4). Simultaneous addition of C. difficile and L. lactis UL719 had no impact on the microbiota cell counts but a significant decrease (p < 0.05) of butyrate (from 32.13 to 28.40 mmol/L). Under these conditions, L. lactis has no inhibitory effect on C. difficile (Figure 3).

Bottom Line: Bacterial populations was enumerated by qPCR coupled to PMA treatment.L. lactis UL719 was able to survive and proliferate under simulated human colon, did not alter microbiota composition, but failed to inhibit C. difficile.While a single dose of 19 μmol/L (5× the MIC) was not sufficient to inhibit C. difficile, nisin at 76 μmol/L (20×the MIC) was effective at killing the pathogen.

View Article: PubMed Central - PubMed

Affiliation: STELA Dairy Research Center, Nutrition and Functional Foods Institute, Université Laval, Québec QC, Canada ; Centre de Recherche en Infectiologie de l'Université Laval, Axe Maladies Infectieuses et Immunitaires, Centre de Recherche du CHU de Québec, Québec QC, Canada ; Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec QC, Canada.

ABSTRACT
Clostridium difficile is the most frequently identified enteric pathogen in patients with nosocomially acquired, antibiotic-associated diarrhea and pseudomembranous colitis. Although metronidazole and vancomycin were effective, an increasing number of treatment failures and recurrence of C. difficile infection are being reported. Use of probiotics, particularly metabolically active lactic acid bacteria, was recently proposed as an alternative for the medical community. The aim of this study was to assess a probiotic candidate, nisin Z-producer Lactococcus lactis UL719, competitivity and nisin (Nisaplin(®)) capacity to inhibit C. difficile in a model of human colon. Bacterial populations was enumerated by qPCR coupled to PMA treatment. L. lactis UL719 was able to survive and proliferate under simulated human colon, did not alter microbiota composition, but failed to inhibit C. difficile. While a single dose of 19 μmol/L (5× the MIC) was not sufficient to inhibit C. difficile, nisin at 76 μmol/L (20×the MIC) was effective at killing the pathogen. Nisin (at 76 μmol/L) caused some temporary changes in the microbiota with Gram-positive bacteria being the mostly affected. These results highlight the capacity of L. lactis UL719 to survive under simulated human colon and the efficacy of nisin as an alternative in the treatment of C. difficile infections.

No MeSH data available.


Related in: MedlinePlus