ABSTRACT
Increasing rates of Clostridium difficile infection (CDI) with an unusual, severe course have been reported in several countries; this rise has partly been ascribed to the emergence of a virulent strain, C. difficile PCR ribotype 027 (CD027). An intriguing question is whether this could be related to increasing consumption of broadspectrum antibiotics. From 1997 to 2007, the number of hospital discharges in Denmark with the diagnosis enterocolitis caused by C. difficile increased from eight to 23 per 100,000 hospital discharges. This increase was proportional to a concomitant rise in the consumption of fluoroquinolones and cephalosporins. The first outbreak of CD027 in Denmark occurred from October 2006 to August 2007 and included 13 patients, most of them elderly, admitted to three hospitals in the same region. Most of the patients had overlapping periods of admission. All patients had been treated with broadspectrum antibiotics, in particular cephalosporins and fluoroquinolones, prior to positive culture of CD027. 30 days after confirmation of diagnosis, three of the 13 patients had died. Taken together, the data support the hypothesis that the increasing use of certain broadspectrum antibiotics may be related to a possible increase of C. difficile infection, and show that the specific contribution by CD027 in its emergence needs to be determined.
Subject(s)
Cephalosporins/adverse effects , Clostridioides difficile/genetics , Fluoroquinolones/adverse effects , Reverse Transcriptase Polymerase Chain Reaction/trends , Ribotyping/trends , Aged , Aged, 80 and over , Cephalosporins/administration & dosage , Clostridioides difficile/drug effects , Denmark , Drug Resistance, Multiple, Bacterial/drug effects , Drug Resistance, Multiple, Bacterial/genetics , Enterocolitis, Pseudomembranous/chemically induced , Enterocolitis, Pseudomembranous/genetics , Female , Fluoroquinolones/administration & dosage , Humans , Male , Middle Aged , Retrospective StudiesABSTRACT
Phenotypic and phylogenetic studies were performed on an unknown, Gram-positive, catalase-negative coccus isolated from human blood. Comparative 16S rRNA gene sequencing demonstrated that the organism represents a new subline within the genus Aerococcus. The unknown bacterium was readily distinguished from the three currently recognized Aerococcus species, Aerococcus christensenii, Aerococcus urinae and Aerococcus viridans, by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that this unknown bacterium from blood be classified as Aerococcus sanguicola sp. nov. The type strain of Aerococcus sanguicola is CCUG 43001T (= CIP 106533T).
