Longitudinal Investigation of Carriage Rates, Counts, and Genotypes of Toxigenic Clostridium difficile in Early Infancy

Abstract

Asymptomatic infant carriers of toxigenic Clostridium difficile are suggested to play a role in the transmission of C. difficile infection (CDI) in adults. However, the mode of C. difficile carriage in infants remains to be fully elucidated. We investigated longitudinal changes in carriage rates, counts, and strain types of toxigenic C. difficile in infants. Stools collected from 111 healthy infants in Belgium periodically from birth until the age of 6 months were examined by quantitative PCR targeting 16S rRNA and toxin genes. Toxigenic C. difficile was detected in 18 of 111 infants (16%) in the period up to the age of 6 months. The carriage rate of toxigenic C. difficile remained below 5% until the age of 3 months. The carriage rate increased to 13% 1 week after weaning (average age, 143 days) and reached 16% at the age of 6 months. Counts of toxigenic C. difficile bacteria ranged from 10 4 to 10 8 cells/g of stool. Notably, two infants retained >10 8 cells/g of stool for at least several weeks. Average counts in the 18 infants hovered around 10 7 cells/g of stool from the age of 3 days until the age of 6 months, showing no age-related trend. Genotyping of toxigenic C. difficile isolates from the 18 infants revealed that 11 infants each retained a particular monophyletic strain for at least a month. The genotype most frequently identified was the same as that frequently identified in symptomatic adult CDI patients. Thus, toxigenic C. difficile strains-potential causes of CDI in adults-colonized the infants' intestines. IMPORTANCEOur study provides longitudinal data on counts and strain types of toxigenic C. difficile in infants. We found that considerable numbers of toxigenic C. difficile bacteria colonized the infants' intestines. The results of strain typing suggest that toxigenic C. difficile carried by healthy infants could be potentially pathogenic to adults. These results and findings are informative not only for ecological studies but also for efforts to prevent or control the spread of CDI in adults. Toxigenic Clostridium difficile is the main cause of health careassociated gastrointestinal infections. In general, C. difficile is not a normal inhabitant of the adult gastrointestinal tract, because its colonization is considered to be prevented by the presence of commensal microbiota (1-3). Colonization of the intestines by toxigenic C. difficile is the first crucial step in the development of C. difficile infection (CDI). Accumulating evidence suggests that disruption of the microbiota and frequent exposure to toxigenic C. difficile could increase the risk of CDI (4-6). Whereas asymptomatic carriage of toxigenic C. difficile is rare in adults, occurring in Ͻ5% of adults (7,8), it is very common in infants (9, 10), probably due to the immaturity of the microbiota composition. Regardless of the high prevalence, a great majority of infants rarely show CDI-related abdominal symptoms. The presumed reason for this is that infants are not susceptible to C. difficile toxins owing to the poor developmen...

High prevalence of toxigenic Clostridium difficile in public space lawns in Western Australia

“…It is also possible that shoes could be vehicles by which C. difficile could be introduced in health care facilities. The detection of C. difficile in lawn could help explain the substantial proportion of cases (45%) of CDI originating from unknown reservoirs as recently described by others 43 44 .…”

Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection and Other Conditions in Children

“…The differentiation of CDI from asymptomatic C difficile carriage remains an ongoing challenge for clinicians. Limitations of the currently available C difficile diagnostic tests and aspects unique to pediatric populations must be taken into account when considering the diagnosis of pediatric CDI: C difficile can be a commensal member of the microbiome during infancy and early childhood (23,24). In an animal model of CDI, infant rabbits have been observed to be resistant to C difficile toxin whereby the distal intestinal tract of the infant rabbit was proposed to lack toxin receptors (25).…”

Modelling diverse sources of Clostridium difficile in the community: importance of animals, infants and asymptomatic carriers

“…Colonised infants [7–10], contaminated food [11] and animals reservoirs [12] have been identified as possible sources of C. difficile outside hospitals, however their contribution to transmission has not been well quantified. Infants under 12 months have much higher prevalence of colonisation than adults [13], can be colonised for over 6 months by a single strain [7] and rarely develop symptoms but shed the same density of spores in their faeces as adults with CDI [8]. However, existing models of C. difficile do not capture infant colonisation or their potential role in transmission.…”