PCR ribotyping and arbitrarily primed PCR for typing strains of Clostridium difficile from a Polish maternity hospital

Abstract

Detection of the source of Clostridium difficile strains is of importance for the control of the nosocomial spread of this microorganism. For this purpose, vaginal and rectal swabs from 183 mothers, duplicate fecal samples (taken on days 1 and 4 after birth) from 183 neonates, and 94 environmental samples were cultured for C. difficile. The microorganism was never detected in the meconium obtained on day 1 after birth. On the other hand, an incidence of 17% C. difficile positivity was noted in the fecal samples obtained on day 4 after birth. Forty-two percent of the 31 colonized neonates had been delivered with complications. The bacteria were never encountered in the rectal swabs of the mothers, and C. difficile was identified in only one vaginal swab. In contrast, 13% of the environmental samples were positive for C. difficile. No major difference was encountered between patient and environmental isolates with respect to toxigenicity (58 to 65% toxigenic isolates). All strains were subsequently typed by PCR amplification of the 16S-23S ribosomal intergenic spacer regions and by arbitrarily primed PCR (AP-PCR) with different primers and combinations thereof. All environmental isolates and 11 of 31 neonatal strains were of a single type. The vaginal strain was unique, and among the maternity ward-and neonate-related isolates, only two additional AP-PCR types were identified. When a collection of C. difficile strains from patients hospitalized in other institutions and suffering from antibioticassociated diarrhea or pseudomembranous colitis was analyzed in a similar manner, it appeared that the strain from the maternity ward was unique. The other strain commonly encountered among the neonates was also identified frequently among the isolates from patients with antibiotic-associated diarrhea or pseudomembranous colitis, indicating its general occurrence. On the basis of both epidemiological studies and PCRmediated genotyping, it was shown that the environment and not the birth canal is the major source of C. difficile acquisition by neonates in this maternity hospital setting. Furthermore, AP-PCR appears to be a fast and useful method for epidemiologically relevant typing of C. difficile isolates.

Patient-to-patient spread of a single strain of Corynebacterium striatum causing infections in a surgical intensive care unit

“…For genotyping, DNA was isolated by the method described by Boom et al (2) from pure cultures of C. striatum strains, a selection of other Corynebacterium isolates from the University Hospital Rotterdam, and reference strains of C. striatum obtained from the Centers for Disease Control and Prevention (CDC; Atlanta, Ga.) and Marie B. Coyle of the Harborview Medical Center (HMC), Seattle, Wash.). DNA was typed by random amplification of polymorphic DNA (RAPD) assays with the ERIC 1 and ERIC 2 primers by previously published procedures (16,24). Strains were considered identical when they showed identical banding patterns on agarose gels or differed by a single band only.…”

Establishment of the gut microbiota in Western infants

“…Other strains derive from infants cared for at the same ward, transferred by the staff (41,43). Klebsiella and Enterobacter spp, enterococci and C. difficile may also pass between infants in a ward (41,44,45). Bifidobacteria of identical type have been demonstrated in maternal and infant faecal microbiota (46), but spread between infants has also been suggested (29).…”

Clonal dissemination of a toxin-A-negative/toxin-B-positive Clostridium difficile strain from patients with antibiotic-associated diarrhea in Poland

“…PCR-mediated ribotyping employed the consensus primers SP1 and SP2. Both PCR tests were performed as described previously [15].…”