Asymptomatic Colonization by Clostridium difficile in Infants: Implications for Disease in Later Life
Approximately 60% to 70% of healthy newborns and infants are colonized by the enteric pathogen Clostridium difficile. For reasons that remain obscure, these colonized infants show no ill effects from the potent exotoxins released by this anaerobe, in contrast to older children and adults who are susceptible to severe diarrhea and colitis. The organism is acquired in infancy, as in adults, from environmental contamination in the nursery or home environment. Between 12 and 24 months C difficile is evicted as a commensal, presumably by the gradual development of the adult colonic microflora. The carrier state is well tolerated by infants, and the immunoglobulin G antitoxin response that develops during the carrier state appears to provide durable protection against subsequent C difficile disease.
Available from: Ruhul Amin
- "Among OTUs found associated with non-diarrheal stool are sequences classified as Clostridum difficile, a surprising finding given that this organism is a common cause of enteric disease, primarily in hospitalized elderly patients. However, although C. difficile can be an important pathogen, it is actually carried asymptomatically by around 60% of infants . We also found a conflicting association of OTUs assigned as Bacteroides fragilis with both the diarrhea-free status and dysentery, a finding that can perhaps be explained by strain-to-strain variation. "
[Show abstract] [Hide abstract]
Diarrheal diseases continue to contribute significantly to morbidity and mortality in infants and young children in developing countries. There is an urgent need to better understand the contributions of novel, potentially uncultured, diarrheal pathogens to severe diarrheal disease, as well as distortions in normal gut microbiota composition that might facilitate severe disease.
We use high throughput 16S rRNA gene sequencing to compare fecal microbiota composition in children under five years of age who have been diagnosed with moderate to severe diarrhea (MSD) with the microbiota from diarrhea-free controls. Our study includes 992 children from four low-income countries in West and East Africa, and Southeast Asia. Known pathogens, as well as bacteria currently not considered as important diarrhea-causing pathogens, are positively associated with MSD, and these include Escherichia/Shigella, and Granulicatella species, and Streptococcus mitis/pneumoniae groups. In both cases and controls, there tend to be distinct negative correlations between facultative anaerobic lineages and obligate anaerobic lineages. Overall genus-level microbiota composition exhibit a shift in controls from low to high levels of Prevotella and in MSD cases from high to low levels of Escherichia/Shigella in younger versus older children; however, there was significant variation among many genera by both site and age.
Our findings expand the current understanding of microbiota-associated diarrhea pathogenicity in young children from developing countries. Our findings are necessarily based on correlative analyses and must be further validated through epidemiological and molecular techniques.
Available from: nature.com
- "Approximately 30% of newborns are colonized with C. difficile with this number decreasing to around 15% by 12 months of age. By age 3, 3%–5% of children are colonized with C. difficile, a percentage similar to adult asymptomatic colonization.70 CDI, which historically has not been identified in pediatric patients less than 2 years of age, has been reported in children as young as 18 months of age caused by flouoroquinolone-resistant C. difficile 027/BI/NAP1.71 "
[Show abstract] [Hide abstract]
ABSTRACT: Clostridium difficile is a spore-forming gram-positive bacillus, and the leading cause of antibiotic-associated nosocomial diarrhea and colitis in the industrialized world. With the emergence of a hypervirulent strain of C. difficile (BI/NAP1/027), the epidemiology of C. difficile infection has rapidly changed in the last decade. C. difficile infection, once thought to be an easy to treat bacterial infection, has evolved into an epidemic that is associated with a high rate of mortality, causing disease in patients thought to be low-risk. In this review, we discuss the changing face of C .difficile infection and the novel treatment and prevention strategies needed to halt this ever growing epidemic.
Available from: Alex Rodriguez-Palacios
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.