Clostridium difficile colonization in healthy adults: transient colonization and correlation with enterococcal colonization

Abstract

The aim of the present study was to investigate the colonization status of Clostridium difficile in healthy individuals. In total, 139 healthy adults from two study groups were examined at intervals of 3 months. Among the 18 positive subjects, the number of subjects from whom C. difficile was isolated once, twice, three times or four times was 10 (55 . 6 %), three (16 . 7 %), two (11 . 1 %) and three (16 . 7 %), respectively. In the student group, different subjects were colonized by different PCR ribotype/PFGE types. However, the same PCR ribotype/PFGE types of C. difficile were isolated from different subjects in the employee group, indicating that cross-transmission may have occurred in this group. Continuous colonization by the same PCR ribotype/PFGE type was only observed in three subjects. C. difficile-positive subjects were significantly more densely colonized by enterococci (P , 0 . 05) than C. difficile-negative subjects: subjects that were found to be C. difficile-positive three or four times appeared to have higher concentrations of enterococci. The present results demonstrate that, although colonization by a C. difficile strain is transient in many cases, there are healthy individuals that are colonized persistently by C. difficile. They also suggest that dense colonization of the intestine by enterococci may be associated with C. difficile colonization.

Prevalence and Duration of Asymptomatic Clostridium difficile Carriage among Healthy Subjects in Pittsburgh, Pennsylvania

“…The prevalence of C. difficile colonization in this small healthy cohort is concordant with contemporary values derived from Japanese populations and is higher than estimates from the United States, many of which were reported prior to the early 2000s (5,(7)(8)(9). This difference may result from the well-documented increase in rates of health care-associated CDIs in the United States since 2000, resulting in spillover into outpatient populations (2).…”

“…The source of C. difficile in community-acquired cases is unclear. Prevalence estimates for asymptomatic C. difficile colonization range from 7 to 15% among healthy, non-health care workers outside the United States to 1 to 4% among health care workers in the United States and abroad (5)(6)(7)(8)(9). Individuals colonized with C. difficile could represent a potential reservoir of strains imported into hospitals, as well as a source of false-positive clinical test results for CDIs among patients with community-acquired diarrheal illness, especially norovirus and Clostridium perfringens.…”

The host immune response to Clostridium difficile infection

“…Colonization rates in healthy humans in the community range from 0.8% to 13% and are higher in long-term care facility residents [Arvand et al 2012;Ozaki et al 2004]. The host immune status plays an important role in protection against symptomatic disease after colonization with C. difficile and it is thought that repeated reinfection from the environment stimulates a protective antibody response in non-hospitalized healthy hosts [Kelly et al 1992;Sanchez-Hurtado et al 2008;Viscidi et al 1983].…”

Protective Efficacy Induced by Recombinant Clostridium difficile Toxin Fragments

“…Although asymptomatic carriage occurs in 4 to 20% of the healthy human population (3)(4)(5)(6)(7)(8), susceptibility to C. difficileassociated infection (CDI) increases with age, hospitalization, immunodeficiency, and antibiotic treatment. Clinical symptoms range from mild to severe diarrhea with relapsing episodes.…”