The relative inhibitory activities of diazabicyclooctanes (avibactam, relebactam, zidebactam, nacubactam, durlobactam), boronic acid derivatives (vaborbactam, taniborbactam, xeruborbactam), and penicillin-based sulfone derivative enmetazobactam were evaluated against several intrinsic and acquired class C β-lactamases. By contrast to vaborbactam and enmetazobactam, taniborbactam, xeruborbactam, and all diazabicyclooctanes demonstrated effective activities against most AmpC enzymes. Notably, durlobactam exhibited the most pronounced inhibitory effect. Interstingly, the chromosomal AmpC of Acinetobacter baumannii was the least sensitive enzyme to the newly developed β-lactamase inhibitors.

• MeSH
• Acinetobacter baumannii * účinky léků   enzymologie   MeSH
• antibakteriální látky * farmakologie   chemie   MeSH
• azabicyklické sloučeniny * farmakologie   chemie   MeSH
• bakteriální proteiny * antagonisté a inhibitory   metabolismus   MeSH
• beta-laktamasy * metabolismus   MeSH
• bicyklické sloučeniny heterocyklické farmakologie   chemie   MeSH
• cyklooktany MeSH
• inhibitory beta-laktamasy * farmakologie   chemie   MeSH
• kyseliny boronové * farmakologie   chemie   MeSH
• laktamy MeSH
• mikrobiální testy citlivosti * MeSH
• peniciliny farmakologie   chemie   MeSH
• piperidiny MeSH
• sulfony farmakologie   chemie   MeSH
• Publikační typ
• časopisecké články MeSH

Fosfomycin (FOS) is an effective antibiotic against multidrug-resistant Enterobacterales, but its effectiveness is reducing. Little is known on the current prevalence of FosA enzymes in low-risk pathogens, such as Citrobacter freundii. The aim of the study was the molecular characterization of a carbapenemase- and FosA-producing C. freundii collected in Italy. AK867, collected in 2023, showed an XDR profile, retaining susceptibility only to colistin. AK867 showed a FOS MIC >128 mg/L by ADM. Based on WGS, AK867 belonged to ST116 and owned a wide resistome, including fosA3, blaKPC-2, and blaVIM-1. fosA3 was carried by a conjugative pKPC-CAV1312 plasmid of 320,480 bp, on a novel composite transposon (12,907 bp). FosA3 transposon shared similarities with other fosA3-harboring pKPC-CAV1312 plasmids among Citrobacter spp. We report the first case of FosA3 production in clinical carbapenemase-producing C. freundii ST116. The incidence of FosA3 enzymes is increasing among Enterobacterales, affecting even low-virulence pathogens, as C. freundii.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• bakteriální proteiny * genetika   metabolismus   MeSH
• beta-laktamasy * genetika   metabolismus   MeSH
• Citrobacter freundii * genetika   enzymologie   účinky léků   MeSH
• enterobakteriální infekce * mikrobiologie   MeSH
• fosfomycin * farmakologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• mnohočetná bakteriální léková rezistence genetika   MeSH
• plazmidy genetika   MeSH
• sekvenování celého genomu MeSH
• transpozibilní elementy DNA MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Itálie MeSH

Fosfomycin-resistant FosA8-producing Enterobacterales are uncommon strains with extremely low incidence in Europe, based on only three reports in the literature. We detected FosA8-producing Escherichia coli ST131 in clinical isolates from two patients admitted in February 2023 to a rehabilitation unit in Italy. The occurrence of rare fosA-like genes in the high-risk clone ST131 is of clinical relevance. The dissemination of FosA-producing E. coli, although still at low levels, should be continuously monitored.

• MeSH
• antibakteriální látky * farmakologie   terapeutické užití   MeSH
• bakteriální léková rezistence MeSH
• beta-laktamasy genetika   metabolismus   MeSH
• Escherichia coli * izolace a purifikace   genetika   účinky léků   MeSH
• fosfomycin farmakologie   terapeutické užití   MeSH
• infekce vyvolané Escherichia coli * mikrobiologie   epidemiologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• multilokusová sekvenční typizace MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Geografické názvy
• Itálie MeSH

INTRODUCTION: In the battle against multidrug-resistant bacterial infections, ceftazidime- avibactam (CZA) stands as a pivotal defense, particularly against carbapenemresistant (CR) Gram-negative pathogens. However, the rise in resistance against this drug poses a significant threat to its effectiveness, highlighting the critical need for in-depth studies about its resistance mechanisms. METHODS: This research focuses on the genomic characterization of CR- and CZA-resistant Escherichia coli (n=26) and Klebsiella pneumoniae (n=34) strains, harboring the blaNDM and/or blaOXA-48-like genes, at a major Lebanese tertiary care medical center, using whole genome sequencing (WGS). RESULTS: Our findings revealed a notable prevalence of blaNDM in all K. pneumoniae strains isolates, with 27 of these also harboring blaOXA-48. On the other hand, E. coli strains predominantly carried the blaNDM-5 gene. Whole genome sequencing (WGS) identified a predominance of ST383 among K. pneumoniae strains, which possessed a multi-replicon IncFIB-IncHI1B plasmid harboring the blaNDM-5. Additionally, various Inc group plasmids in K. pneumoniae across multiple sequence types were found to carry the blaNDM. Similarly, diverse STs of E. coli were observed to carry blaNDM-5 on different plasmids. DISCUSSION: The study underscores NDM carbapenemases as a paramount resistance mechanism in Lebanon,jeopardizing critical last-resort treatments. It also illuminates the role of varied sequence types and mobile genetic elements in the spread of NDM resistance,stressing the urgent need for strategies to mitigate this threat, especially in nosocomial infections.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• azabicyklické sloučeniny * farmakologie   MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• beta-laktamasy * genetika   metabolismus   MeSH
• ceftazidim * farmakologie   MeSH
• centra terciární péče MeSH
• Enterobacteriaceae rezistentní na karbapenemy genetika   účinky léků   izolace a purifikace   MeSH
• Escherichia coli * genetika   účinky léků   MeSH
• fixní kombinace léků * MeSH
• genom bakteriální MeSH
• karbapenemy * farmakologie   MeSH
• Klebsiella pneumoniae * genetika   účinky léků   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• mnohočetná bakteriální léková rezistence * genetika   MeSH
• plazmidy genetika   MeSH
• přenos genů horizontální MeSH
• sekvenování celého genomu * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Libanon MeSH

β-Lactamases (EC 3.5.2.6) confer resistance against β-lactam group-containing antibiotics in bacteria and higher eukaryotes, including humans. Pathogenic bacterial resistance against β-lactam antibiotics is a primary concern for potential therapeutic developments and drug targets. Here, we report putative β-lactamase activity, sulbactam binding (a β-lactam analogue) in the low μM affinity range, and site-specific interaction studies of a 14 kDa UV- and dark-inducible protein (abbreviated as UVI31+, a BolA homologue) from Chlamydomonas reinhartii. Intriguingly, the solution NMR structure of UVI31 + bears no resemblance to other known β-lactamases; however, the sulbactam binding is found at two sites rich in positively charged residues, mainly at the L2 loop regions and the N-terminus. Using NMR spectroscopy, ITC and MD simulations, we map the ligand binding sites in UVI31 + providing atomic-level insights into its β-lactamase activity. Current study is the first report on β-lactamase activity of UVI31+, a BolA analogue, from C. reinhartii. Furthermore, our mutation studies reveal that the active site serine-55 is crucial for β-lactamase activity.

• MeSH
• beta-laktamasy * chemie   metabolismus   MeSH
• Chlamydomonas reinhardtii * enzymologie   MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• nukleární magnetická rezonance biomolekulární metody   MeSH
• rostlinné proteiny chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• simulace molekulární dynamiky MeSH
• sulbaktam chemie   farmakologie   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH

Epithelial-mesenchymal transition (EMT) is a cellular mechanism used by cancer cells to acquire migratory and stemness properties. In this study, we show, through in vitro, in vivo, and 3D culture experiments, that the mitochondrial protein LACTB manifests tumor suppressor properties in ovarian cancer. We show that LACTB is significantly down-regulated in epithelial ovarian cancer cells and clinical tissues. Re-expression of LACTB negatively effects the growth of cancer cells but not of non-tumorigenic cells. Mechanistically, we show that LACTB leads to differentiation of ovarian cancer cells and loss of their stemness properties, which is achieved through the inhibition of the EMT program and the LACTB-dependent down-regulation of Snail2/Slug transcription factor. This study uncovers a novel role of LACTB in ovarian cancer and proposes new ways of counteracting the oncogenic EMT program in this model system.

• MeSH
• beta-laktamasy * genetika   metabolismus   MeSH
• epitelo-mezenchymální tranzice * genetika   MeSH
• karcinogeneze MeSH
• lidé MeSH
• membránové proteiny genetika   metabolismus   MeSH
• mitochondriální proteiny genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory vaječníků * genetika   metabolismus   patologie   MeSH
• rodina transkripčních faktorů Snail * genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: LACTB was recently identified as a mitochondrial tumour suppressor that negatively affects cancer cell proliferation by inducing cell death and/or differentiation, depending on the cell type and tissue. However, the detailed mechanism underlying the LACTB-induced cancer cell death is largely unknown. METHODS: We used cell-based, either in 2D or 3D conditions, and in vivo experiments to understand the LACTB mechanisms. In this regard, protein array followed by an enrichment analysis, cell proliferation assays using different compounds, western blot analysis, flow cytometry and immunofluorescence were performed. Differences between quantitative variables following normal distribution were valuated using Student t test for paired or no-paired samples according to the experiment. For in vivo experiments differences in tumour growth were analyzed by 2-way ANOVA. RESULTS: We show, that LACTB expression leads to cell cycle arrest in G1 phase and increase of DNA oxidation that leads to activation of intrinsic caspase-independent cell death pathway. This is achieved by an increase of mitochondrial reactive oxygen species since early time points of LACTB induction. CONCLUSION: Our work provides a deeper mechanistic insight into LACTB-mediated cancer-cell death and shows the dynamics of the cellular responses a particular tumor suppressive stimulus might evoke under different genetic landscapes.

• MeSH
• apoptóza genetika   MeSH
• beta-laktamasy genetika   metabolismus   MeSH
• kaspasy * genetika   metabolismus   MeSH
• kontrolní body buněčného cyklu MeSH
• lidé MeSH
• membránové proteiny genetika   MeSH
• mitochondriální proteiny genetika   MeSH
• nádorové buněčné linie MeSH
• nádory prsu * genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The objective of this study was to assess the susceptibility of cefiderocol against multidrug-resistant carbapenemase-producing and nonproducing bacteria. The panel comprised 182 isolates of the order Enterobacterales, and 40 strains of Pseudomonas aeruginosa. Antimicrobial susceptibility testing has been performed using broth microdilution method according to the European Committee on Antimicrobial Susceptibility Testing recommendations. Mass spectrometry matrix-assisted laser desorption/ionization-time of flight mass spectrometry and carbapenemase-producing test were used to verify the presence of carbapenemases in clinical isolates. The genetic expression of single carbapenemases (blaKPC, blaOXA-48, blaNDM, blaVIM, blaIMP, blaGES) was determined by real-time polymerase chain reaction. Cefiderocol exhibited a good activity against the majority of strains tested in this study. Altogether, growth of 81.9% (n = 149) strains of the order Enterobacterales and 77.5% (n = 31) of P. aeruginosa isolates were inhibited at minimal inhibitory concentration (MIC) ≤2 mg/L. Values MIC50/MIC90 were 0.5/8 mg/L for enterobacteria, and 1/8 mg/L for P. aeruginosa. One isolate (Klebsiella pneumoniae) harboring two carbapenemases (blaOXA-48, blaNDM) had cefiderocol MIC 0.5 mg/L. In enterobacteria resistant to cefiderocol, blaNDM carbapenemase prevailed (43.3%, n = 29), followed by blaOXA-48 (31.3%, n = 21) and blaKPC (4.5%, n = 3). blaIMP (n = 8) and blaVIM (n = 1) metallo-β-lactamases dominated in cefiderocol-resistant P. aeruginosa (n = 9) isolates. Very good susceptibility (100%) to this drug showed blaGES-positive strains of P. aeruginosa (n = 8) and isolates resistant to meropenem without confirmed carbapenemase gene (n = 10). In this study, cefiderocol demonstrated potent activity against important nosocomial pathogens, therefore, therapeutic options of this drug against multidrug-resistant bacteria should be considered.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• beta-laktamasy genetika   metabolismus   MeSH
• cefiderokol MeSH
• Enterobacteriaceae genetika   metabolismus   MeSH
• karbapenemy * farmakologie   MeSH
• mikrobiální testy citlivosti MeSH
• Pseudomonas aeruginosa MeSH
• Publikační typ
• časopisecké články MeSH

The aim of the present study is to describe the ongoing spread of the KPC-producing strains, which is evolving to an epidemic in Czech hospitals. During the period of 2018-2019, a total of 108 KPC-producing Enterobacterales were recovered from 20 hospitals. Analysis of long-read sequencing data revealed the presence of several types of blaKPC-carrying plasmids; 19 out of 25 blaKPC-carrying plasmids could be assigned to R (n = 12), N (n = 5), C (n = 1) and P6 (n = 1) incompatibility (Inc) groups. Five of the remaining blaKPC-carrying plasmids were multireplicon, while one plasmid couldn't be typed. Additionally, phylogenetic analysis confirmed the spread of blaKPC-carrying plasmids among different clones of diverse Enterobacterales species. Our findings demonstrated that the increased prevalence of KPC-producing isolates was due to plasmids spreading among different species. In some districts, the local dissemination of IncR and IncN plasmids was observed. Additionally, the ongoing evolution of blaKPC-carrying plasmids, through genetic rearrangements, favours the preservation and further dissemination of these mobile genetic elements. Therefore, the situation should be monitored, and immediate infection control should be implemented in hospitals reporting KPC-producing strains.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální léková rezistence * MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• beta-laktamasy metabolismus   MeSH
• epidemie MeSH
• infekce bakteriemi rodu Klebsiella epidemiologie   mikrobiologie   MeSH
• Klebsiella pneumoniae izolace a purifikace   metabolismus   MeSH
• lidé MeSH
• nemocnice statistika a číselné údaje   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Increasing antimicrobial resistance of nosocomial pathogens is becoming a serious threat to public health. To control the spread of this resistance, it is necessary to detect β-lactamase-producing organisms in the clinical setting. The aims of the study were to design a PCR assay for rapid detection of clinically encountered β-lactamase genes described in Enterobacteriaceae and Gram-negative non-fermenting bacteria. The functionality of proposed primers was verified using eight reference strains and 17 strains from our collection, which contained 29 different β-lactamase genes. PCR products of the test strains were confirmed by Sanger sequencing. Sequence analysis was performed using bioinformatics software Geneious. Overall, 67 pairs of primers for detecting 12 members of the class C β-lactamase family, 15 members of class A β-lactamases, six gene families of subclass B1, one member each of subclasses B2, B3 and class D β-lactamases were designed, of which 43 pairs were experimentally tested in vitro. All 29 β-lactamase genes, including 10 oxacillinase subgroups, were correctly identified by PCR. The proposed set of primers should be able to specifically detect 99.7% of analyzed β-lactamase subtypes and more than 79.8% of all described β-lactamase genes.

• MeSH
• Bacteria enzymologie   genetika   izolace a purifikace   MeSH
• bakteriologické techniky * MeSH
• beta-laktamasy genetika   metabolismus   MeSH
• beta-laktamová rezistence genetika   MeSH
• DNA bakterií genetika   MeSH
• DNA primery MeSH
• lidé MeSH
• polymerázová řetězová reakce * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH