Presence of hypervirulence-associated determinants in Klebsiella pneumoniae from hospitalised patients in Germany.

BACKGROUND: Klebsiella (K.) pneumoniae is a ubiquitous Gram-negative bacterium and a common coloniser of animals and humans. Today, K. pneumoniae is one of the most persistent nosocomial pathogens worldwide and poses a severe threat/burden to public health by causing urinary tract infections, pneumonia and bloodstream infections. Infections mainly affect immunocompromised individuals and hospitalised patients. In recent years, a new type of K. pneumoniae has emerged associated with community-acquired infections such as pyogenic liver abscess in otherwise healthy individuals and is therefore termed hypervirulent K. pneumoniae (hvKp). The aim of this study was the characterisation of K. pneumoniae isolates with properties of hypervirulence from Germany. METHODS: A set of 62 potentially hypervirulent K. pneumoniae isolates from human patients was compiled. Inclusion criteria were the presence of at least one determinant that has been previously associated with hypervirulence: (I) clinical manifestation, (II) a positive string test as a marker for hypermucoviscosity, and (III) presence of virulence associated genes rmpA and/or rmpA2 and/or magA. Phenotypic characterisation of the isolates included antimicrobial resistance testing by broth microdilution. Whole genome sequencing (WGS) was performed using Illumina® MiSeq/NextSeq to investigate the genetic repertoire such as multi-locus sequence types (ST), capsule types (K), further virulence associated genes and resistance genes of the collected isolates. For selected isolates long-read sequencing was applied and plasmid sequences with resistance and virulence determinants were compared. RESULTS: WGS analyses confirmed presence of several signature genes for hvKp. Among them, the most prevalent were the siderophore loci iuc and ybt and the capsule regulator genes rmpA and rmpA2. The most dominant ST among the hvKp isolates were ST395 capsule type K2 and ST395 capsule type K5; both have been described previously and were confirmed by our data as multidrug-resistant (MDR) isolates. ST23 capsule type K1 was the second most abundant ST in this study; this ST has been described as commonly associated with hypervirulence. In general, resistance to beta-lactams caused by the production of extended-spectrum beta-lactamases (ESBL) and carbapenemases was observed frequently in our isolates, confirming the threatening rise of MDR-hvKp strains. CONCLUSIONS: Our study results show that K. pneumoniae strains that carry several determinants of hypervirulence are present for many years in Germany. The detection of carbapenemase genes and hypervirulence associated genes on the same plasmid is highly problematic and requires intensified screening and molecular surveillance. However, the non-uniform definition of hvKp complicates their detection. Testing for hypermucoviscosity alone is not specific enough to identify hvKp. Thus, we suggest that the classification of hvKp should be applied to isolates that not only fulfil phenotypical criteria (severe clinical manifestations, hypermucoviscosity) but also (I) the presence of at least two virulence loci e.g. iuc and ybt, and (II) the presence of rmpA and/or rmpA2.

Improving leadership skills of infection prevention and control teams by psychological empowerment: study protocol for a cluster randomised controlled trial (IP-POWER).

INTRODUCTION: Infection prevention and control (IPC) teams are routinely confronted with intense emotions in their daily work, as they are involved in many change processes with front-line medical staff, for example, when promoting compliance with basic IPC measures. In addition, they are confronted with challenges due to their role as intermediaries. Based on former research, this study aims to empower IPC teams to promote clinicians' compliance through interventions focusing on the IPC teams' leadership skills. METHODS AND ANALYSIS: The IP-POWER study (Infection Prevention with head and heart: Psychological empowerment of IPC teams), a multicentre, two-arm, non-blinded, cluster-randomised controlled trial with a parallel waiting control group, is planned to be conducted in Germany as of February to November 2024. A group of 10 voluntary hospitals is going to participate in a multistage intervention programme, including 2 days of intense psychological training; 5 hospitals will be randomly assigned to the waiting control group. After the workshops, there will be a 12-week follow-up period during which the contents learnt within the workshops can be applied and internalised into IPC practice. The proposed outcomes (both self-assessed and other-assessed leadership competencies of IPC team members and their task profiles, perceived workload, motivation to act in order to implement IP measures and goal attainment) are going to be collected with an online questionnaire, followed by an analysis with IBM SPSS (Statistics 29 (or later)) using descriptive analyses and multiple linear regressions. Additionally, as external data sources, hand hygiene compliance rates from the study hospitals' monitoring systems will be analysed using χ² tests. ETHICS AND DISSEMINATION: This study was reviewed and approved by the ethics committee of the University of Leipzig (184/23-ek; vote from 4 July 2023). Findings will be disseminated via peer-review publications, and national and international conference presentations. TRIAL REGISTRATION NUMBER: DRKS00031879.