RESUMO
BACKGROUND: The pandemic of carbapenem-resistant Enterobacteriaceae (CRE) was primarily due to clonal spread of bla KPC producing Klebsiella pneumoniae. Thus, thoroughly studied CRE cohorts have consisted mostly of K. pneumoniae. OBJECTIVE: To conduct an extensive epidemiologic analysis of carbapenem-resistant Enterobacter spp. (CREn) from 2 endemic and geographically distinct centers. METHODS: CREn were investigated at an Israeli center (Assaf Harofeh Medical Center, January 2007 to July 2012) and at a US center (Detroit Medical Center, September 2008 to September 2009). bla KPC genes were queried by polymerase chain reaction. Repetitive extragenic palindromic polymerase chain reaction and pulsed-field gel electrophoresis were used to determine genetic relatedness. RESULTS: In this analysis, 68 unique patients with CREn were enrolled. Sixteen isolates (24%) were from wounds, and 33 (48%) represented colonization only. All isolates exhibited a positive Modified Hodge Test, but only 93% (27 of 29) contained bla KPC. Forty-three isolates (63%) were from elderly adults, and 5 (7.4%) were from neonates. Twenty-seven patients died in hospital (40.3% of infected patients). Enterobacter strains consisted of 4 separate clones from Assaf Harofeh Medical Center and of 4 distinct clones from Detroit Medical Center. CONCLUSIONS: In this study conducted at 2 distinct CRE endemic regions, there were unique epidemiologic features to CREn: (i) polyclonality, (ii) neonates accounting for more than 7% of cohort, and (iii) high rate of colonization (almost one-half of all cases represented colonization). Since false-positive Modified Hodge Tests in Enterobacter spp. are common, close monitoring of carbapenem resistance mechanisms (particularly carbapenemase production) among Enterobacter spp. is important.
Assuntos
Farmacorresistência Bacteriana , Enterobacter/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Tempo de Internação/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Enterobacter/genética , Feminino , Humanos , Israel , Estimativa de Kaplan-Meier , Klebsiella pneumoniae/genética , Modelos Logísticos , Masculino , Michigan , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Análise Multivariada , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Epidemiological characteristics of patients with bloodstream infections (BSI) due to extended-spectrum ß-lactamase producing (ESBL) and carbapenem-resistant (CRE) strains are often similar. Mortality rates for CRE BSI are 70%, and mean time to initiation of appropriate therapy is ~5 days. A bedside score was developed to differentiate CRE-BSIs from ESBL-BSIs, in order to help decrease the time to initiation of appropriate therapy for CRE and mortality rates. FINDINGS: Score was developed based of data (2007-2010) abstracted from charts of adult patients from Assaf Harofeh Medical Center (AHMC, Zeriffin, Israel), and validated on a cohort of patients from Detroit Medical Center (DMC, MI, USA). A multivariate model for presence of CRE was generated. A clinical prediction score and ROC curve was derived. 451 patients with ESBL BSIs (285 from AHMC and 166 from DMC) and 74 patients with CRE BSIs (58 from AHMC and 16 from DMC) were included. The prediction score included chemotherapy in the past 3 months (19 points), presence of foreign invasive devices (10 points), no peripheral vascular disease (10 points), reduced consciousness or cognition at time of acute illness (9 points), time in hospital prior to BSI ≥ 3 days (7 points), and age younger than 65 years (6 points). A score of ≥32 to define "high CRE risk" had sensitivity of 59%, specificity of 76%, PPV of 34% and NPV of 90%. CONCLUSIONS: The score's 90% NPV implies it could reduce un-necessary (and toxic) empiric use of anti-CRE therapeutics, but this should be studied prospectively and on broader populations in order to test its potential role in reducing mortality.
Assuntos
Antibacterianos/administração & dosagem , Bacteriemia/tratamento farmacológico , Proteínas de Bactérias/metabolismo , Técnicas de Apoio para a Decisão , Infecções por Enterobacteriaceae/tratamento farmacológico , Resistência beta-Lactâmica , beta-Lactamases/metabolismo , Adulto , Feminino , Humanos , Israel , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Estados UnidosRESUMO
A recent, frequently quoted study has suggested that for bloodstream infections (BSIs) due to extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL) Escherichia coli, treatment with ß-lactam/ß-lactamase inhibitors (BLBLIs) might be equivalent to treatment with carbapenems. However, the majority of BSIs originate from the urinary tract. A multicenter, multinational efficacy analysis was conducted from 2010 to 2012 to compare outcomes of patients with non-urinary ESBL BSIs who received a carbapenem (69 patients) vs those treated with piperacillin-tazobactam (10 patients). In multivariate analysis, therapy with piperacillin-tazobactam was associated with increased 90-day mortality (adjusted odds ratio, 7.9, P=.03). For ESBL BSIs of a non-urinary origin, carbapenems should be considered a superior treatment to BLBLIs.
