ABSTRACT
Resistance to daptomycin in enterococcal clinical isolates remains rare but is being increasingly reported in the United States and worldwide. There are limited data on the genetic relatedness and microbiological and clinical characteristics of daptomycin-nonsusceptible enterococcal clinical isolates. In this study, we assessed the population genetics of daptomycin-nonsusceptible Enterococcus faecium (DNSE) clinical isolates by multilocus sequence typing (MLST) and whole-genome sequencing analysis. Forty-two nonduplicate DNSE isolates and 43 randomly selected daptomycin-susceptible E. faecium isolates were included in the analysis. All E. faecium isolates were recovered from patients at a tertiary care medical center in suburban New York City from May 2009 through December 2013. The daptomycin MICs of the DNSE isolates ranged from 6 to >256 µg/ml. Three major clones of E. faecium (ST18, ST412, and ST736) were identified among these clinical isolates by MLST and whole-genome sequence-based analysis. A newly recognized clone, ST736, was seen in 32 of 42 (76.2%) DNSE isolates and in only 14 of 43 (32.6%) daptomycin-susceptible E. faecium isolates (P < 0.0001). This report provides evidence of the association between E. faecium clone ST736 and daptomycin nonsusceptibility. The identification and potential spread of this novel E. faecium clone and its association with daptomycin nonsusceptibility constitute a challenge for patient management and infection control at our medical center.
Subject(s)
Anti-Bacterial Agents/pharmacology , Daptomycin/pharmacology , Enterococcus faecium/drug effects , Enterococcus faecium/genetics , Genome, Bacterial , Gram-Positive Bacterial Infections/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Clone Cells , Drug Resistance, Bacterial/genetics , Enterococcus faecium/classification , Enterococcus faecium/isolation & purification , Female , Gram-Positive Bacterial Infections/microbiology , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Multilocus Sequence Typing , New York City , Sequence Analysis, DNA , Tertiary Care CentersABSTRACT
A case series of 10 patients with a diagnosis of borderline personality disorder (BPD) presenting with auditory hallucinosis is examined. In this series, the hallucinations were persistent, longstanding, and a significant source of distress and disability. Extrapolating from this series to our sample of 171 patients with BPD suggests that a form of auditory hallucinosis may occur in almost 30% of this population. The failure to emphasize this phenomenon in current systems of classification risks misdiagnosis or inappropriate treatment. Use of terms such as pseudohallucination or quasi hallucination dismisses the phenomenon as unimportant or as "not real." There is an emerging literature on the frequency of hallucinosis among nonpatients. A basis for understanding different forms of hallucination is discussed with reference to the concept of "normativity." We propose a nomenclature for hallucinosis that is expressed in positive terms, reflecting the clinical significance of the phenomenon in different contexts: (1) normative hallucinosis, (2) traumatic-intrusive hallucinosis (as in our series), (3) psychotic hallucinosis, and (4) organic hallucinosis.
