Nosocomial Outbreak of VIM-1-Producing Klebsiella pneumoniae Isolates of Multilocus Sequence Type 15: Molecular Basis, Clinical Risk Factors, and Outcome

Abstract

We study the epidemiology, molecular basis, clinical risk factors, and outcome involved in the clonal dissemination of VIM-1-producing Klebsiella pneumoniae isolates in the hospital setting. All patients infected/colonized by carbapenem-nonsusceptible K. pneumoniae (CNSKP) in 2009 were included. Molecular epidemiology was studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic resistance genes were analyzed by PCR and sequencing. Plasmids were studied by PFGE with S1 nuclease digestion and for incompatibility group by a PCR-based replicon typing scheme. Risk factors associated with CNSKP colonization/infection were assessed by an observational case-control study. All 55 patients studied were infected (n ‫؍‬ 28) or colonized (n ‫؍‬ 27) by VIM-1-producing K. pneumoniae. All but one acquired isolates of a single clone (PFGE cluster 1 [C1], sequence type 15 [ST15]), while another clone (PFGE C2, ST340) was detected in four patients. C1 isolates also produced the new extended-spectrum ␤-lactamase SHV-134. bla VIM-1 was carried in a class 1 integron and an untypeable plasmid of ϳ50 bp. The number of days that the patient received mechanical ventilation, the use of parenteral nutrition, previous treatment with linezolid, and treatment with extended-spectrum cephalosporins for more than 7 days were detected to be independent risk factors for CNSKP acquisition. The VIM-1-producing K. pneumoniae ST15 clone has a high capacity to spread among intensive care unit patients with severe underlying conditions. A high rate of associated mortality and great difficulty in controlling the spread of this clone, without permanent behavioral changes in the personnel, were observed.

Outbreak of a Cluster with Epidemic Behavior Due to Serratia marcescens after Colistin Administration in a Hospital Setting

“…Recently, the ability of certain Gram-negative bacilli, including Enterobacter cloacae and K. pneumoniae, to cause nosocomial out- . Each asterisk indicates statistically significant differences (P Ͻ 0.05) between the data in the column with the asterisk above and the data in the one or two columns that are linked with lines coming out of the asterisk, as determined using the statistical analysis described in detail in Table 3. breaks associated with the spread of epidemic multidrug-resistant clusters carrying integrons has been documented (30)(31)(32). In the present study, the sporadic isolates of S. marcescens found before and after the outbreak did not possess class 1 integrons (Table 1).…”

“…S. marcescens is a well-recognized cause of hospital-acquired infection during the three last decades, mainly in areas of risk and immunocompromised patients. Several outbreaks, more commonly in neonatal units than in adults, have been documented and were associated with a single cluster (32,33) as well as with the combination of two or more clusters (3,34). Here, the mean age of the patients in the clinical area of the H1 hospital was 53 years, a bit higher than what is found in the literature (32)(33)(34)(35).…”

“…Several outbreaks, more commonly in neonatal units than in adults, have been documented and were associated with a single cluster (32,33) as well as with the combination of two or more clusters (3,34). Here, the mean age of the patients in the clinical area of the H1 hospital was 53 years, a bit higher than what is found in the literature (32)(33)(34)(35). Although an environmental source, mainly hospital settings and fomites, has been found in some outbreaks (13,36), most of these events were characterized by the lack of a detectable cause (2,34).…”

Detection of carbapenemase-producing Enterobacteriaceae in rectal surveillance cultures in non-hospitalized patients

“…The characterization of blaNDM was firstly published in December 2009 (Yong et al 2009) and its presence was then detected in almost the entire world (Cornaglia et al 2011). BlaOXA-48 carbapenemases belong to Ambler class D. The prevalence of CPE in Spain remains low and is mainly related to VIM-producing isolates (Sánchez-Romero et al 2012). Nevertheless, KPC-2-, KPC-3-, NDM-1-, and OXA-48-producing Enterobacteriaceae were recently detected in Spain (Solé et al 2011).…”

Hygienemaßnahmen bei Infektionen oder Besiedlung mit multiresistenten gramnegativen Stäbchen

“…[191]. In entsprechenden Studien konnte eine vorhergehende Antibiotikatherapie bei Infektionen durch K. pneumoniae mit ESBL [192,193] oder CarbapenemResistenz [189,194] als unabhängiger Risikofaktor identifiziert werden. Eine andere Studie konnte zwar nicht eine Antibiotikatherapie per se als signifikanten Risikofaktor für Carbapenem-resistente K. pneumoniae identifizieren, jedoch die Anzahl der vorher verabreichten Antibiotika [187].…”