A Case of Lactobacillus Bacteremia during Probiotic Supplementation in a Very Preterm Infant with Short Bowel Syndrome

Probiotics are living micro-organisms that beneficially affect the composition of the host intestinal microflora. In very preterm infants, probiotics reportedly help reduce necrotizing enterocolitis (NEC), invasive fugal colonization and sepsis, and enable the establishment of complete enteral feeding at an earlier stage. However, emerging evidence has indicated the risk of potential side effects of probiotic use, such as gut organism translocation, including probiotic organisms, in infants that are more premature. In the present report, we describe a case of Lactobacillus bacteremia in a very preterm infant with short bowel syndrome. Lactobacillus sepsis developed during the therapeutic use of this organism for diarrhea and diarrhea-related malabsorption. The organism isolated from the blood sample was found to be of the same strain as that administered, by using molecular techniques. The findings of the present case suggest that probiotics should be carefully used, particularly in very preterm infants with altered intestinal permeability such as short bowel syndrome.

In Vitro Evaluation of Antimicrobial Activity of Lactic Acid Bacteria against Clostridium difficile

Clostridium difficile infection (CDI) has become a significant threat to public health. Although broad-spectrum antibiotic therapy is the primary treatment option for CDI, its use has evident limitations. Probiotics have been proved to be effective in the treatment of CDI and are a promising therapeutic option for CDI. In this study, 4 strains of lactic acid bacteria (LAB), namely, Lactobacillus rhamnosus (LR5), Lactococ-cuslactis (SL3), Bifidobacterium breve (BR3), and Bifidobacterium lactis (BL3) were evaluated for their anti-C. difficile activity. Co-culture incubation of C. difficile (106 and 1010 CFU/ml) with each strain of LAB indicated that SL3 possessed the highest antimicrobial activity over a 24-hr period. The cell-free supernatants of the 4 LAB strains exhibited MIC50 values between 0.424 mg/ml (SL3) and 1.318 (BR3) mg/ml. These results may provide a basis for alternative therapies for the treatment of C. difficile-associated gut disorders.

A Study on the Prevention of Salmonella Infection by Using the Aggregation Characteristics of Lactic Acid Bacteria

Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.