Analysis of DNA Restriction Fragment Length Polymorphism Extends the Evidence for Breast Milk Transmission in Streptococcus agalactiae Late-Onset Neonatal Infection

Abstract

Analysis of restriction fragment length polymorphism (RFLP) of total DNA and of ribosomal DNA (ribotyping) was used to document four cases of Streptococcus agalactiae mother-to-infant transmission potentially associated with ingestion of infected mother's milk. Twenty strains were analyzed. Ten strains were mother-baby pairs, five from the milk of five mothers, four from their neonates with late-onset infection, and one from a colonized neonate. All mothers had early postpartum mastitis. Ten unrelated strains were studied for comparison. In each case, the two strains of each mother-baby pair produced identical RFLP patterns of total DNA. The 10 unrelated strains generated 10 different patterns, one of which, though, was observed in one of the mother-baby pairs. Ribotyping was less discriminative than total DNA RFLP analysis (6 different patterns vs. 13). These data extend the evidence for breast milk transmission in S. agalactiae late-onset neonatal infection.

Multiple Insertional Events, Restricted by the Genetic Background, Have Led to Acquisition of Pathogenicity Island II J96 -Like Domains among Escherichia coli Strains of Different Clinical Origins

“…The main phylogenetic groups (A, B1, B2, and D) were determined for all strains by using previously described PCR methods (11), and B2 strains were subgrouped by ribotyping with the restriction enzyme HindIII and with 16S and 23S rRNAs as the probes (1,(3)(4)(5).…”

Burkholderia cepaciaIs Associated with Pulmonary Hypertension and Increased Mortality among Cystic Fibrosis Patients

“…The isolates were grown in 10 ml of nutrient broth (Sanofi Diagnostic Pasteur) for 18 h, and DNA was prepared from the bacterial pellet as previously described (2,3). DNA was digested with EcoRI (Boehringer, Mannheim, Germany) according to the manufacturer's instructions and analyzed by Southern blotting with a chemiluminescent ribosomal probe (2). Identification of genomovars was determined as previously described (20).…”

Use of ribotyping in epidemiological surveillance of nosocomial outbreaks

“…Other labelling molecules have been used. In our studies, 16S+23S rRNA from E. coli was cold labelled by random oligopriming, using a mixture of hexanucleotide primers and cloned mouse mammary leukemia virus reverse transcriptase (115) in the presence of deoxynucleotide triphosphates, including digoxigenin-11-dUTP (18) (Fig. 5).…”