Clostridia in premature neonates' gut: incidence, antibiotic susceptibility, and perinatal determinants influencing colonization.

BACKGROUND: Although premature neonates (PN) gut microbiota has been studied, data about gut clostridial colonization in PN are scarce. Few studies have reported clostridia colonization in PN whereas Bacteroides and bifidobacteria have been seldom isolated. Such aberrant gut microbiota has been suggested to be a risk factor for the development of intestinal infections. Besides, PN are often treated by broad spectrum antibiotics, but little is known about how antibiotics can influence clostridial colonization based on their susceptibility patterns. The aim of this study was to report the distribution of Clostridium species isolated in feces from PN and to determine their antimicrobial susceptibility patterns. Additionally, clostridial colonization perinatal determinants were analyzed. RESULTS: Of the 76 PN followed until hospital discharge in three French neonatal intensive care units (NICUs), 79% were colonized by clostridia. Clostridium sp. colonization, with a high diversity of species, increased throughout the hospitalization. Antibiotic courses had no effect on the clostridial colonization incidence although strains were found susceptible (except C. difficile) to anti-anaerobe molecules tested. However, levels of colonization were decreased by either antenatal or neonatal (during more than 10 days) antibiotic courses (p = 0.006 and p = 0.001, respectively). Besides, incidence of colonization was depending on the NICU (p = 0.048). CONCLUSION: This study shows that clostridia are part of the PN gut microbiota. It provides for the first time information on the status of clostridia antimicrobial susceptibility in PN showing that strains were susceptible to most antibiotic molecules. Thus, the high prevalence of this genus is not linked to a high degree of resistance to antimicrobial agents or to the use of antibiotics in NICUs. The main perinatal determinant influencing PN clostridia colonization appears to be the NICU environment.

Vaginal carriage and neonatal acquisition of Clostridium difficile.

The relationship between vaginal carriage and subsequent neonatal acquisition of Clostridium difficile was investigated. Vaginal carriage of C. difficile was detected in 11% of women attending the Department of Genital Medicine Clinic. C. difficile was isolated from the vagina in 18% of 50 mothers before delivery, and 8% after delivery; 62% of their babies had positive faecal cultures. Eight of nine of the babies whose mothers had positive cultures before delivery became colonised with C. difficile, while 23 of 41 babies whose mothers had negative cultures became colonised. This suggests that both the vagina and the environment may act as sources of neonatal acquisition of C. difficile. Broth enrichment culture proved a more sensitive method for isolating C. difficile from the vagina than direct plate culture and should be used in such investigations.