Emerging research

Clostridium difficile

Clostridium difficile – also known as C. diff or C. difficile – is an opportunistic pathogen present in the stool samples of around 1-3% of healthy adults and up to 80% of healthy newborns and infants (Bartlett, 2002; Viscidi et al, 1981). It is known to be the most common nosocomial diarrhoeal pathogen in hospitalised patients and very important in terms of cost and extended stays in hospitals (Kuijper et al, 2006; Vonberg et al, 2008). Treatment of a C. difficile infection usually involves taking antibiotics. However, nearly a quarter of patients relapse within two months and the risk of additional recurrences increases to 50-65% after two or more episodes of the infection.

A study testing four commercial probiotic strains and products (including Symprove) was carried out with the aim of investigating the influence of some commercial probiotics on the growth of C. difficile using isothermal microcalorimetry (IMC), an instrument which has been established to measure bacterial growth in real time by monitoring net metabolic heat output, giving characteristic signatures for individual bacteria that are proportional to their growth. The study found that Symprove had inhibitory activity against C. difficile through altering the pH level in the environment and producing by-product substances that suppressed the growth of C. difficile.

 

Mansa Fredua-Agyeman, Paul Stapleton, Abdul W. Basit, Anthony E. Beezer, Simon Gaisford

In vitro inhibition of Clostridium difficile by commercial probiotics: A microcalorimetric study

 

Abstract

The aim of the study was to investigate the influence of some commercial probiotics on the growth of Clostridium difficile using isothermal microcalorimetry, a technique which can monitor the real time growth of bacteria. Commercial probiotic strains and products, Lactobacillus acidophilus LA-51, Bifidobacterium lactis BB-121, Probio 71 and SymproveTM were co-cultured with C. difficile in Brain Heart Infusion (BHI) broth supplemented with 0.1% (w/v) L-cysteine hydrochloride and 0.1% (w/v) sodium taurocholate and monitored in the microcalorimeter. Pseudomonas aeruginosa NCIMB 8628 was also co-cultured with C. difficile and studied. The results indicated inhibition of C. difficile by the probiotics. The inhibition of C. difficile was shown to be pH-dependent using neutralized and unmodified cell free supernatant (CFS) produced by the probiotic strains. However, concentrated CFS of the probiotics also inhibited the intestinal pathogen in a non pH-dependent manner, likely due to specific antimicrobial substances produced. The results also indicated that C. difficile growth was greatly influenced by the presence of sodium taurocholate and by the pH of the medium. A medium pH of between 6.45 and 6.9 demonstrated maximum growth of the organism in the microcalorimeter.

International Journal of Pharmaceutics 517 (2017) 96–103