Dataset Information

Surveillance of carbapenem-resistant Klebsiella pneumoniae: tracking molecular epidemiology and outcomes through a regional network.

ABSTRACT: Carbapenem resistance in Gram-negative bacteria is on the rise in the United States. A regional network was established to study microbiological and genetic determinants of clinical outcomes in hospitalized patients with carbapenem-resistant (CR) Klebsiella pneumoniae in a prospective, multicenter, observational study. To this end, predefined clinical characteristics and outcomes were recorded and K. pneumoniae isolates were analyzed for strain typing and resistance mechanism determination. In a 14-month period, 251 patients were included. While most of the patients were admitted from long-term care settings, 28% of them were admitted from home. Hospitalizations were prolonged and complicated. Nonsusceptibility to colistin and tigecycline occurred in isolates from 7 and 45% of the patients, respectively. Most of the CR K. pneumoniae isolates belonged to repetitive extragenic palindromic PCR (rep-PCR) types A and B (both sequence type 258) and carried either blaKPC-2 (48%) or blaKPC-3 (51%). One isolate tested positive for blaNDM-1, a sentinel discovery in this region. Important differences between strain types were noted; rep-PCR type B strains were associated with blaKPC-3 (odds ratio [OR], 294; 95% confidence interval [CI], 58 to 2,552; P < 0.001), gentamicin nonsusceptibility (OR, 24; 95% CI, 8.39 to 79.38; P < 0.001), amikacin susceptibility (OR, 11.0; 95% CI, 3.21 to 42.42; P < 0.001), tigecycline nonsusceptibility (OR, 5.34; 95% CI, 1.30 to 36.41; P = 0.018), a shorter length of stay (OR, 0.98; 95% CI, 0.95 to 1.00; P = 0.043), and admission from a skilled-nursing facility (OR, 3.09; 95% CI, 1.26 to 8.08; P = 0.013). Our analysis shows that (i) CR K. pneumoniae is seen primarily in the elderly long-term care population and that (ii) regional monitoring of CR K. pneumoniae reveals insights into molecular characteristics. This work highlights the crucial role of ongoing surveillance of carbapenem resistance determinants.

SUBMITTER: van Duin D

PROVIDER: S-EPMC4068524 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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Surveillance of carbapenem-resistant Klebsiella pneumoniae: tracking molecular epidemiology and outcomes through a regional network.

van Duin David D Perez Federico F Rudin Susan D SD Cober Eric E Hanrahan Jennifer J Ziegler Julie J Webber Raymond R Fox Jacqueline J Mason Pamela P Richter Sandra S SS Cline Marianne M Hall Geraldine S GS Kaye Keith S KS Jacobs Michael R MR Kalayjian Robert C RC Salata Robert A RA Segre Julia A JA Conlan Sean S Evans Scott S Fowler Vance G VG Bonomo Robert A RA

Antimicrobial agents and chemotherapy 20140505 7

Carbapenem resistance in Gram-negative bacteria is on the rise in the United States. A regional network was established to study microbiological and genetic determinants of clinical outcomes in hospitalized patients with carbapenem-resistant (CR) Klebsiella pneumoniae in a prospective, multicenter, observational study. To this end, predefined clinical characteristics and outcomes were recorded and K. pneumoniae isolates were analyzed for strain typing and resistance mechanism determination. In a ...[more]

PMID: 24798270

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Project description:Hypervirulent Klebsiella pneumoniae (hvKp) can cause infections in clinically healthy people, such as young and immunocompetent patients. Genes involved in the capsule synthesis or those encoding the siderophores have been adopted as predictors of hvKp. Certain sequence types, such as ST23 and ST86, have been associated with hvKp strains, too. The aim of this study was to investigate the presence of hvKp among 354 K. pneumoniae strains isolated from clinical samples of patients admitted to an Italian 900-bed hospital between 21 May 2021 and April 2022. All the isolates were screened by PCR for the amplification of virulence loci. Whole genome sequencing was performed in strains tested positive for at least one target gene. Thirteen out of 354 (3.7%) were hvKp. Five were wild type and belonged to the hypervirulent clones ST23, ST86, ST5, and ST375 and to the new clone ST6310. Six strains carried the blaKPC gene: three belonged to ST101, two to ST512, and one to ST395. Two isolates were ST147 and carried the blaNDM gene. Although hvKp isolation is not frequent, their presence should be systematically investigated to avoid the spreading of both virulent strains and strains with combined increase in virulence and resistance to antibiotics. PCR-based protocols are essential for surveillance of these strains, which do not always show a recognizable phenotype. Moreover, hvKp strains were isolated also from patients without history of recent foreign travels, indicating an increased spreading of these strains as well as an underestimated of their circulation so far.IMPORTANCEKlebsiella pneumoniae is a healthcare-associated pathogen frequently resistant to antibiotics. Hypervirulent strains of pneumoniae (hvKp) can spread from the primary site of infection to multiple sites causing life-threatening infections also in young otherwise healthy individuals. This study described the isolation of 13 isolates of K. pneumoniae with increased virulence in a large tertiary hospital over a 1-year period. Among them, eight strains were multidrug resistant and hypervirulent. Although these hypervirulent strains are still rare in Italy, their presence is particularly concerning since they can cause difficult-to-treat life-threatening infections. Moreover, not all the hypervirulent isolates were positive by the string test, so hvKp isolates were not always phenotypically detectable. Molecular biology techniques such as PCR amplification and next generation sequencing are therefore necessary for the detection of hvKp isolates, and surveillance programs exploiting molecular techniques are highly desirable.

Project description:Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global public health threat. In this study, we employed whole-genome sequencing (WGS) to determine the genomic epidemiology of a longitudinal collection of clinical CRKP isolates recovered from a large public acute care hospital in Singapore. Phylogenetic analyses, a characterization of resistance and virulence determinants, and plasmid profiling were performed for 575 unique CRKP isolates collected between 2009 and 2020. The phylogenetic analyses identified the presence of global high-risk clones among the CRKP population (clonal group [CG] 14/15, CG17/20, CG147, CG258, and sequence type [ST] 231), and these clones constituted 50% of the isolates. Carbapenemase production was common (n = 497, 86.4%), and KPC was the predominant carbapenemase (n = 235, 40.9%), followed by OXA-48-like (n = 128, 22.3%) and NDM (n = 93, 16.2%). Hypervirulence was detected in 59 (10.3%) isolates and was most common in the ST231 carbapenemase-producing isolates (21/59, 35.6%). Carbapenemase genes were associated with diverse plasmid replicons; however, there was an association of blaOXA-181/232 with ColKP3 plasmids. This study presents the complex and diverse epidemiology of the CRKP strains circulating in Singapore. Our study highlights the utility of WGS-based genomic surveillance in tracking the population dynamics of CRKP. IMPORTANCE In this study, we characterized carbapenem-resistant Klebsiella pneumoniae clinical isolates collected over a 12-year period in the largest public acute-care hospital in Singapore using whole-genome sequencing. The results of this study demonstrate significant genomic diversity with the presence of well-known epidemic, multidrug-resistant clones amid a diverse pool of nonepidemic lineages. Genomic surveillance involving comprehensive resistance, virulence, and plasmid gene content profiling provided critical information for antimicrobial resistance monitoring and highlighted future surveillance priorities, such as the emergence of ST231 K. pneumoniae strains bearing multidrug resistance, virulence elements, and the potential plasmid-mediated transmission of the blaOXA-48-like gene. The findings here also reinforce the necessity of unique infection control and prevention strategies that take the genomic diversity of local circulating strains into consideration.

Project description:Background: The increasing prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses an immediate threat to treatment worldwide. This retrospective study assessed the molecular epidemiology and determined the risk factors for and outcomes of CRKP infections in a general teaching hospital in Shanghai, China. Methods: From January 2013 to July 2015, 100 consecutive unique CRKP isolates isolated from hospitalized patients were collected. Isolates were screened for antibiotic resistance genes by polymerase chain reaction and molecular typing was performed by pulsed-field gel electrophoresis (PFGE). Patients infected with CRKP comprised the case group and were compared to the control group of patients infected with carbapenem-susceptible Klebsiella pneumoniae. Therapeutic effects were compared in the CRKP infection group. Results: Among the 100 CRKP isolates, the percentages of multidrug-resistant, extensively drug-resistant (XDR), and pandrug-resistant were 50.0, 50.0, and 0%, respectively. All the CRKP isolates produced KPC-2 and could be divided into 18 PFGE clusters (A-O) and 70 subtypes. No dominant intra-hospital PFGE type was detected using a cutoff of 80% similarity. The ratio of CRKP infection to colonization was 51 to 49. Risk factors correlated with CRKP infection included pulmonary disease (p = 0.038), ICU stay (p = 0.002), invasive ventilation (p = 0.009), blood transfusion (p = 0.028), parenteral nutrition (p = 0.004), sputum suction (p = 0.006), medical history of previous hospitalization (p = 0.022), exposure to antibiotics 90 days before infection (p = 0.030), and antibiotic exposure during hospital stay including carbapenems (p = 0.013), enzyme inhibitors (p = 0.021), nitroimidazoles (p = 0.029), and glycopeptides (p = 0.000). Multivariable analysis showed that sputum suction (odds ratio 3.090, 95% confidence intervals 1.004-9.518, p = 0.049) was an independent risk factor for CRKP infections. Patients infected with CRKP with longer carbapenems treatment course (p = 0.002) showed better outcome. Conclusion: This study showed the severity of CRKP infection in eastern China. Sputum suction was an independent risk factor for CRKP infection. Prolonged duration of treatment with carbapenems benefited the patients infected with CRKP.

Project description:Carbapenem-resistantKlebsiella pneumoniae(CR-Kp) is significant threat to public health worldwide. The primary reservoir for CR-Kp is the intestinal tract, where the bacterium is usually present at low density, but can bloom following antibiotic treatment, mostly in hospital settings. The impact of disturbances in the intestinal environment on the fitness, survival, expansion, and drug susceptibility of this pathogen is not well-understood. Nevertheless, gaining such knowledge could lead to innovative intervention strategies for addressing colonization and infection. Here, we adopted anin vivomodel to examine the transcriptional adaptation of a CR-Kp clinical isolate to immune activation in the intestine. We report that as early as 6 hours following host treatment with anti-CD3 antibody, CR-Kp underwent rapid transcriptional changes including downregulation of genes involved in sugar utilization and amino acid biosynthesis, and upregulation of genes involved in amino acid uptake and catabolism, antibiotic resistance, and stress response. In agreement with these findings, the concentration of oxidative species and amino acids was increased in the mouse intestine following treatment. Genes encoding for proteins containing the domain of unknown function (DUF) 1471 were particularly upregulated, however their deletion did not impair CR-Kp fitness in vivoupon immune activation. Transcription factor enrichment analysis identified the global regulator cAMP-Receptor Protein CRP as a potential orchestrator of the observed transcriptional signature. In keeping with the recognized role of CRP in regulating utilization of alternative carbon sources, CRP deletion in CR-Kp resulted in strongly impaired gut colonization, but this effect was not amplified by immune activation. Thus, following intestinal colonization, which occurs in a CRP-dependent manner, CR-Kp can rapidly respond to immune cues by implementing a well-defined and complex transcriptional program whose direct relevance towards bacterial fitness remains cryptic. Further analyses utilizing this model may identify key factors to tackle the intestinal stage of CR-Kp colonization.

Dataset Information

Surveillance of carbapenem-resistant Klebsiella pneumoniae: tracking molecular epidemiology and outcomes through a regional network.

Publications

Surveillance of carbapenem-resistant Klebsiella pneumoniae: tracking molecular epidemiology and outcomes through a regional network.

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