Clinical and molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli as a cause of nosocomial infection or colonization: implications for control.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing members of the Enterobacteriaceae family are important nosocomial pathogens. Escherichia coli producing a specific family of ESBL (the CTX-M enzymes) are emerging worldwide. The epidemiology of these organisms as causes of nosocomial infection is poorly understood. The aims of this study were to investigate the clinical and molecular epidemiology of nosocomial infection or colonization due to ESBL-producing E. coli in hospitalized patients, consider the specific types of ESBLs produced, and identify the risk factors for infection and colonization with these organisms. METHODS: All patients with nosocomial colonization and/or infection due to ESBL-producing E. coli in 2 centers (a tertiary care hospital and a geriatric care center) identified between January 2001 and May 2002 were included. A double case-control study was performed. The clonal relatedness of the isolates was studied by repetitive extragenic palindromic-polymerase chain reaction and pulsed-field gel electrophoresis. ESBLs were characterized by isoelectric focusing, polymerase chain reaction, and sequencing. RESULTS: Forty-seven case patients were included. CTX-M-producing E. coli were clonally unrelated and more frequently susceptible to nonoxyimino-beta-lactams. Alternately, isolates producing SHV- and TEM-type ESBL were epidemic and multidrug resistant. Urinary catheterization was a risk factor for both CTX-M-producing and SHV-TEM-producing isolates. Previous oxyimino-beta-lactam use, diabetes, and ultimately fatal or nonfatal underlying diseases were independent risk factors for infection or colonization with CTX-M-producing isolates, whereas previous fluoroquinolone use was associated with infection or colonization with SHV-TEM-producing isolates. CONCLUSIONS: The epidemiology of ESBL-producing E. coli as a cause of nosocomial infection is complex. Sporadic CTX-M-producing isolates coexisted with epidemic multidrug-resistant SHV-TEM-producing isolates. These data should be taken into account for the design of control measures.

Validity and reliability of the Spanish version of the DN4 (Douleur Neuropathique 4 questions) questionnaire for differential diagnosis of pain syndromes associated to a neuropathic or somatic component

BACKGROUND This study assesses the validity and reliability of the Spanish version of DN4 questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component (non-neuropathic pain, NNP). METHODS A study was conducted consisting of two phases: cultural adaptation into the Spanish language by means of conceptual equivalence, including forward and backward translations in duplicate and cognitive debriefing, and testing of psychometric properties in patients with NP (peripheral, central and mixed) and NNP. The analysis of psychometric properties included reliability (internal consistency, inter-rater agreement and test-retest reliability) and validity (ROC curve analysis, agreement with the reference diagnosis and determination of sensitivity, specificity, and positive and negative predictive values in different subsamples according to type of NP). RESULTS A sample of 164 subjects (99 women, 60.4%; age: 60.4 +/- 16.0 years), 94 (57.3%) with NP (36 with peripheral, 32 with central, and 26 with mixed pain) and 70 with NNP was enrolled. The questionnaire was reliable [Cronbach's alpha coefficient: 0.71, inter-rater agreement coefficient: 0.80 (0.71-0.89), and test-retest intra-class correlation coefficient: 0.95 (0.92-0.97)] and valid for a cut-off value > or = 4 points, which was the best value to discriminate between NP and NNP subjects. DISCUSSION This study, representing the first validation of the DN4 questionnaire into another language different than the original, not only supported its high discriminatory value for identification of neuropathic pain, but also provided supplemental psychometric validation (i.e. test-retest reliability, influence of educational level and pain intensity) and showed its validity in mixed pain syndromes.