Antimicrobial effect of sulconazole in combination with glucose/trehalose against carbapenem-resistant hypervirulent Klebsiella pneumoniae persisters.
Microbiological research
The emergence and rapid dissemination of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) pose a serious threat to public health. Antibiotic treatment failure of K. pneumoniae infections has been largely attributed to acquisition of antibiotic resistance and bacterial biofilm caused by the presence of antibiotic persisters. There is an urgent need for novel antimicrobial agents or therapy strategies to manage infections caused by these notorious pathogens. In this study, we screened a collection of compounds that can dissipate bacterial proton motive force (PMF) and intermediate metabolites that can suppress antibiotic tolerance, and identified an antifungal drug sulconazole which can act in combination with glucose or trehalose to exert strong antibacterial effect against starvation-induced CR-hvKP persisters. Investigation of underlying mechanisms showed that sulconazole alone caused dissipation of transmembrane PMF, and sulconazole used in combination with glucose or trehalose could significantly inhibit the efflux activity, reduce NADH and ATP levels, and cause intracellular accumulation of reactive oxygen species (ROS) in CR-hvKP persisters, eventually resulting in bacterial cell death. These findings suggest that the sulconazole and glucose/trehalose combination is highly effective in eradicating multidrug-resistant and hypervirulent K. pneumoniae persisters, and may be used in development of a feasible strategy for treatment of chronic and recurrent K. pneumoniae infections.
10.1016/j.micres.2024.128006
Rapid design of bacteriophage cocktails to suppress the burden and virulence of gut-resident carbapenem-resistant Klebsiella pneumoniae.
Cell host & microbe
Antibiotic use can lead to the expansion of multi-drug-resistant pathobionts within the gut microbiome that can cause life-threatening infections. Selective alternatives to conventional antibiotics are in dire need. Here, we describe a Klebsiella PhageBank for the tailored design of bacteriophage cocktails to treat multi-drug-resistant Klebsiella pneumoniae. Using a transposon library in carbapenem-resistant K. pneumoniae, we identify host factors required for phage infection in major Klebsiella phage families. Leveraging the diversity of the PhageBank, we formulate phage combinations that eliminate K. pneumoniae with minimal phage resistance. Optimized cocktails selectively suppress the burden of K. pneumoniae in the mouse gut and drive the loss of key virulence factors that act as phage receptors. Phage-mediated diversification of bacterial populations in the gut leads to co-evolution of phage variants with higher virulence and broader host range. Altogether, the Klebsiella PhageBank charts a roadmap for phage therapy against a critical multidrug-resistant human pathogen.
10.1016/j.chom.2024.09.004
Chasing the landscape for intrahospital transmission and evolution of hypervirulent carbapenem-resistant Klebsiella pneumoniae.
Science bulletin
The spread of hypervirulent carbapenem-resistant Klebsiella pneumoniae (Hv-CRKP) is a global health concern. Here, we report the intrahospital colonization and spread of Hv-CRKP isolates in a tertiary hospital from 2017 to 2022. Analyses of 90 nonredundant CRKP isolates from 72 patients indicated that Hv-CRKP transferability relies on the dominant ST11-K64 clone. Whole-genome sequencing of 11 representative isolates gave 31 complete plasmid sequences, including 12 KPC-2 resistance carriers and 10 RmpA virulence vehicles. Apart from the binary vehicles, we detected two types of fusion plasmids, favoring the cotransfer of RmpA virulence and KPC-2 resistance. The detection of ancestry/relic plasmids enabled us to establish genetic mechanisms by which rare fusion plasmids form. Unexpectedly, we found a total of five rmpA promoter variants (P-P) exhibiting distinct activities and varying markedly in their geographic distributions. CRISPR/Cas9 manipulation confirmed that an active P-rmpA regulator is a biomarker for the "high-risk" ST11-K64/CRKP clone. These findings suggest clonal spread and clinical evolution of the prevalent ST11-K64/Hv-CRKP clones. Apart from improved public awareness of Hv-CRKP convergence, our findings might benefit the development of surveillance (and/or intervention) strategies for the dominant ST11-K64 lineage of the Hv-CRKP population in healthcare sectors.
10.1016/j.scib.2023.10.038
Carbapenem-resistant Klebsiella pneumoniae capsular types, antibiotic resistance and virulence factors in China: a longitudinal, multi-centre study.
Nature microbiology
Epidemiological knowledge of circulating carbapenem-resistant Klebsiella pneumoniae (CRKP) is needed to develop effective strategies against this public health threat. Here we present a longitudinal analysis of 1,017 CRKP isolates recovered from patients from 40 hospitals across China between 2016 and 2020. Virulence gene and capsule typing revealed expansion of CRKP capsule type KL64 (59.5%) alongside decreases in KL47 prevalence. Hypervirulent CRKP increased in prevalence from 28.2% in 2016 to 45.7% in 2020. Phylogenetic and spatiotemporal analysis revealed Beijing and Shanghai as transmission hubs accounting for differential geographical prevalence of KL47 and KL64 strains across China. Moderate frequency capsule or O-antigen loss was also detected among isolates. Non-capsular CRKP were more susceptible to phagocytosis, attenuated during mouse infections, but showed increased serum resistance and biofilm formation. These findings give insight into CRKP serotype prevalence and dynamics, revealing the importance of monitoring serotype shifts for the future development of immunological strategies against CRKP infections.
10.1038/s41564-024-01612-1
Expansion and transmission dynamics of high risk carbapenem-resistant Klebsiella pneumoniae subclones in China: An epidemiological, spatial, genomic analysis.
Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy
AIMS:Carbapenem-resistant Klebsiella pneumonia (CRKP) is a global threat that varies by region. The global distribution, evolution, and clinical implications of the ST11 CRKP clone remain obscure. METHODS:We conducted a multicenter molecular epidemiological survey using isolates obtained from 28 provinces and municipalities across China between 2011 and 2021. We integrated sequences from public databases and performed genetic epidemiology analysis of ST11 CRKP. RESULTS:Among ST11 CRKP, KL64 serotypes exhibited considerable expansion, increasing from 1.54% to 46.08% between 2011 and 2021. Combining our data with public databases, the phylogenetic and phylogeography analyses indicated that ST11 CRKP appeared in the Americas in 1996 and spread worldwide, with key clones progressing from China's southeastern coast to the inland by 2010. Global phylogenetic analysis showed that ST11 KL64 CRKP has evolved to a virulent, resistant clade with notable regional spread. Single-nucleotide polymorphism (SNP) analysis identified BMPPS (bmr3, mltC, pyrB, ppsC, and sdaC) as a key marker for this clade. The BMPPS SNP clade is associated with high mortality and has strong anti-phagocytic and competitive traits in vitro. CONCLUSIONS:The high-risk ST11 KL64 CRKP subclone showed strong expansion potential and survival advantages, probably owing to genetic factors.
10.1016/j.drup.2024.101083
Emergence of silent NDM-1 carbapenemase gene in carbapenem-susceptible Klebsiella pneumoniae: Clinical implications and epidemiological insights.
Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy
The global dissemination of carbapenemase genes, particularly bla, poses a significant threat to public health. While research has mainly focused on strains with phenotypic resistance, the impact of silent resistance genes has been largely overlooked. This study documents the first instance of silent bla in a cluster of clonally related carbapenem-susceptible K. pneumoniae strains from a single patient. Despite initial effectiveness of carbapenem therapy, the patient experienced four recurrent lung infections over five months, indicating persistent K. pneumoniae infection. Genomic sequencing revealed all strains harbored bla on the epidemic IncX3 plasmid. A deletion within the upstream promoter region (P) of bla hindered its expression, resulting in phenotypic susceptibility to carbapenems. However, in vitro bactericidal assays and a mouse infection model showed that K. pneumoniae strains with silent bla exhibited significant tolerance to carbapenem-mediated killing. These findings demonstrate that silent bla can mediate both phenotypic susceptibility and antibiotic tolerance. In silico analysis of 1986 bla sequences showed that 1956 (98.5%) retained the original promoter P. Given that previous genomic sequencing typically targets carbapenem-resistant strains, accurately assessing the prevalence of silent bla remains challenging. This study highlights the hidden threat of silent resistance genes to clinical antimicrobial therapy and calls for enhanced clinical awareness and laboratory detection.
10.1016/j.drup.2024.101123
An increased prevalence of carbapenem-resistant hypervirulent Klebsiella pneumoniae associated with the COVID-19 pandemic.
Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy
BACKGROUND:Klebsiella pneumoniae (Kp) is a common community-acquired and nosocomial pathogen. Carbapenem-resistant and hypervirulent (CR-hvKp) variants can emerge rapidly within healthcare facilities and impacted by other infectious agents such as COVID-19 virus. METHODS:To understand the impact of COVID-19 virus on the prevalence of CR-hvKp, we accessed Kp genomes with corresponding metadata from GenBank. Sequence types (STs), antimicrobial resistance genes, and virulence genes, and those scores and CR-hvKp were identified. We analyzed population diversity and phylogenetic characteristics of five most common STs, measured the prevalence of CR-hvKp, identified CR-hvKp subtypes, and determined associations between carbapenem resistance gene subtypes with STs and plasmid types. These variables were compared pre- and during the COVID-19 pandemic. FINDINGS:The proportion of CR-hvKp isolates increased within multiple STs in different continents during the COVID-19 pandemic and persistent CR-hvKp subtypes were found in common STs. bla was dominant in CG258, bla was detected in 97 % of the ST11 CR-hvKp, bla subtypes were prominent in ST147 (87.4 %) and ST307 (70.8 %); bla and its subtypes were prevalent in ST15 (80.5 %). The possession of carbapenemase genes was different among subclades from different origins in different periods of time within each ST. IncFIB/IncHI1B hybrid plasmids contained virulence genes and carbapenemase genes and were predominant in ST147 (67.37 %) and ST307 (56.25 %). INTERPRETATION:The prevalence of CR-hvKp increased during the COVID-19 pandemic, which was evident by an increase in local endemic clones. This process was facilitated by the convergence of plasmids containing carbapenemase genes and virulence genes. These findings have implications for the appropriate use of antimicrobials and infection prevention and control during outbreaks of respiratory viruses and pandemic management.
10.1016/j.drup.2024.101124