Zosuquidar (LY335979) is a widely used experimental P-glycoprotein (P-gp) inhibitor, which is commended as very potent but also as very specific for P-gp. In this in vitro and in silico study, we demonstrated for the first time that zosuquidar also inhibits organic cation transporters (OCT) 1-3, albeit less potently than P-gp. This still has to be kept in mind when zosuquidar is used to inhibit cellular efflux of P-gp substrates that are concurrently transported into the cells by OCTs. To avoid interference in these assays, zosuquidar concentrations should be kept below 1 μM.

• MeSH
• Quinolines * pharmacology   MeSH
• Dibenzocycloheptenes MeSH
• HEK293 Cells MeSH
• Humans MeSH
• ATP Binding Cassette Transporter, Subfamily B, Member 1 * antagonists & inhibitors   MeSH
• Organic Cation Transport Proteins * antagonists & inhibitors   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Bacterial resistance has become a global concern for public health agencies. Various resistance mechanisms found in Staphylococcus aureus strains grant this bacterium resistance to a wide range of antibiotics, contributing to the rise in human mortality worldwide. Resistance mediated by efflux pumps is one of the most prevalent mechanisms in multi-resistant bacteria, which has aroused the interest of several researchers in the search for possible efflux pump inhibitors. In view of the aforementioned considerations, it is important that new strategies, such as the synthesis of chalcones, be made available as a viable strategy in antimicrobial therapy. In this study, the synthesized chalcone (2E)-1-(3'-aminophenyl)-3-(4-dimethylaminophenyl)-prop-2-en-1-one was tested for its antibacterial activity, focusing on antibiotic modification and the inhibition of the MepA efflux pump present in S. aureus strain K2068. The broth microdilution method, using microdilution plates, was employed in microbiological tests to determine the minimum inhibitory concentration of the chalcone, antibiotics, and ethidium bromide. The results show that while the chalcone did not exhibit direct antibacterial activity, it synergistically enhanced the effects of ciprofloxacin and ethidium bromide, as evidenced by the reduction in MICs. In addition, computer simulations of molecular docking demonstrate that the tested chalcone acts on the same binding site as the efflux pump inhibitor chlorpromazine, interacting with essentially the same residues. These data suggest that the chalcone may act as a MepA inhibitor.

• MeSH
• Anti-Bacterial Agents * pharmacology   chemistry   chemical synthesis   MeSH
• Bacterial Proteins * metabolism   genetics   chemistry   antagonists & inhibitors   MeSH
• Chalcone * pharmacology   chemistry   MeSH
• Chalcones * pharmacology   chemistry   MeSH
• Humans MeSH
• Membrane Transport Proteins * metabolism   genetics   chemistry   MeSH
• Microbial Sensitivity Tests MeSH
• Multidrug Resistance-Associated Proteins * metabolism   genetics   chemistry   MeSH
• Molecular Docking Simulation MeSH
• Staphylococcus aureus * drug effects   genetics   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

The spread of multidrug-resistant Escherichia coli in healthcare facilities is a global challenge. Hospital-acquired infections produced by Escherichia coli include gastrointestinal, blood-borne, urinary tract, surgical sites, and neonatal infections. Therefore, novel approaches are needed to deal with this pathogen and its rising resistance. The concept of attenuating virulence factors is an alternative strategy that might lead to low levels of resistance and combat this pathogen. A sub-inhibitory concentration (1⁄4 MIC) of sitagliptin and nitazoxanide was used for phenotypic assessments of Escherichia coli virulence factors such as biofilm production, swimming motility, serum resistance, and protease production. Moreover, qRT-PCR was used to determine the impact of sub-MIC of the tested drugs on the relative expression levels of papC, fimH, fliC, kpsMTII, ompT_m, and stcE genes encoding virulence factors in Escherichia coli. Also, an in vivo model was conducted as a confirmatory test. Phenotypically, our findings demonstrated that the tested strains showed a significant decrease in all the tested virulence factors. Moreover, the genotypic results showed a significant downregulation in the relative expression levels of all the tested genes. Besides, the examined drugs were found to be effective in protecting mice against Escherichia coli pathogenesis. Sitagliptin and nitazoxanide exhibited strong anti-virulence activities against Escherichia coli. In addition, it is recommended that they might function as adjuvant in the management of Escherichia coli infections with either conventional antimicrobial agents or alone as alternative treatment measures.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Biofilms drug effects   MeSH
• Nitro Compounds MeSH
• Escherichia coli * drug effects   pathogenicity   genetics   MeSH
• Virulence Factors genetics   metabolism   MeSH
• Escherichia coli Infections * drug therapy   microbiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Drug Resistance, Multiple, Bacterial MeSH
• Mice MeSH
• Escherichia coli Proteins genetics   MeSH
• Sitagliptin Phosphate * pharmacology   MeSH
• Thiazoles * pharmacology   MeSH
• Virulence drug effects   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The rapid evolution and spread of multidrug resistance among bacterial pathogens has significantly outpaced the development of new antibiotics, underscoring the urgent need for alternative therapies. Antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy have emerged as promising treatments. Antimicrobial photodynamic therapy relies on the interaction between light and a photosensitizer to produce reactive oxygen species, which are highly cytotoxic to microorganisms, leading to their destruction without fostering resistance. Antimicrobial sonodynamic therapy, a novel variation, substitutes ultrasound for light to activate the sonosensitizers, expanding the therapeutic reach. To increase the efficiency of antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy, the combination of these two methods, known as antimicrobial photo-sonodynamic therapy, is currently being explored and considered a promising approach. Recent advances, particularly in the application of nanomaterials, have further enhanced the efficacy of these therapies. Nanosensitizers, due to their improved reactive oxygen species generation and targeted delivery, offer significant advantages in overcoming the limitations of conventional sensitizers. These breakthroughs provide new avenues for treating bacterial infections, especially multidrug-resistant strains and biofilm-associated infections. Continued research, including comprehensive clinical studies, is crucial to optimizing nanomaterial-based antimicrobial photo-sonodynamic therapy for clinical use, ensuring their effectiveness in real-world applications.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Bacteria drug effects   MeSH
• Bacterial Infections * drug therapy   microbiology   therapy   MeSH
• Biofilms drug effects   MeSH
• Photochemotherapy * methods   MeSH
• Photosensitizing Agents * pharmacology   MeSH
• Humans MeSH
• Nanoparticles chemistry   MeSH
• Nanostructures chemistry   MeSH
• Reactive Oxygen Species metabolism   MeSH
• Ultrasonic Therapy MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Epidemic form of acute hemorrhagic conjunctivitis was reported from different geographical locations of the world, during 2023. Since the viral agents are well established behind acute hemorrhagic conjunctivitis outbreaks, this study aims to investigate the bacterial agent associated with the acute hemorrhagic conjunctivitis outbreak that occurred in the eastern Uttar Pradesh region of India. The bacterial infection was investigated in 91 conjunctival swabs collected from acute hemorrhagic conjunctivitis patients during the outbreak. Total nucleic acid was extracted from the ocular swab collected from acute hemorrhagic conjunctivitis patients, followed by the detection of human adenovirus and pan-enterovirus using PCR. Further, the isolation of bacteria was performed using these clinical samples. Characterization of the bacterial isolates was done using the VITEK-2 system and 16S ribosomal RNA sequencing. Of 64 conjunctival swabs positive for coxsackievirus-A24 samples, two clinical specimens showed bacterial growth. Both isolates were identified as Ochrobactrum anthropi via VITEK-2 with 93% and 95% confidence levels. While 16S ribosomal RNA analysis characterized the isolates as Ochrobactrum intermedium. Ochrobactrum intermedium is an emerging multidrug-resistant bacterium and is reported to cause a variety of clinical infections. This study first reported the Ochrobactrum intermedium infection in two coxsackievirus-A24 infected acute hemorrhagic conjunctivitis patients.

• MeSH
• Conjunctivitis, Acute Hemorrhagic * virology   microbiology   epidemiology   MeSH
• Coxsackievirus Infections * virology   epidemiology   MeSH
• Adult MeSH
• Disease Outbreaks MeSH
• Phylogeny MeSH
• Gram-Negative Bacterial Infections * microbiology   epidemiology   MeSH
• Coinfection * microbiology   virology   epidemiology   MeSH
• Humans MeSH
• Enterovirus C, Human isolation & purification   MeSH
• Ochrobactrum * isolation & purification   genetics   classification   MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• India MeSH

Cíl: Cílem studie bylo zmapovat výskyt bakterií Staphylococcus aureus a meticilin-rezistentních Staphylococcus aureus v prostředí univerzitního kampusu. Důraz byl kladen na identifikaci potenciálně rizikových míst z hlediska častého kontaktu s povrchy a vysoké koncentrace osob. Metody: Vzorkování probíhalo na předem vytipovaných lokalitách univerzity za použití sterilních stěrových houbiček. Odebraný materiál byl pomnožen v pufrované peptonové vodě (24 hod, 37 °C) a dále kultivován na selektivních médiích. Výskyt bakterií Staphylococcus aureus a meticilin-rezistentních Staphylococcus aureus byl potvrzen pomocí metody PCR. U izolátů meticilin-rezistentních S. aureus byly dále detekovány geny virulence, určeny spa typy a testována rezistence k antimikrobikům. Výsledky: Celkem bylo analyzováno 312 vzorků odebraných z povrchů v univerzitních koridorech, knihovně a dvou stravovacích zařízeních. S. aureus byl detekován ve 210 vzorcích (67,3 %). Získáno bylo také 8 izolátů meticilin-rezistentních S. aureus (2,6 %). Identifikovány byly spa typy meticilin-rezistentních S. aureus t304 (častý na Blízkém východě) a t011 náležející ke klonální linii ST398, t126 a t189. Tři izoláty meticilin-rezistentních S. aureus byly klasifikovány jako multirezistentní. Závěr: Výsledky poukazují na významnou kontaminaci univerzitního prostředí bakteriemi Staphylococcus aureus a meticilin- rezistentních Staphylococcus aureus, zejména na površích s vysokou frekvencí dotyku. Zdůrazňuje se potřeba časté a cílené dezinfekce, vhodné volby čisticích prostředků a důsledné podpory hygieny rukou mezi studenty i zaměstnanci. Monitoring těchto patogenů může být klíčovým nástrojem prevence komunitního šíření, a to i s ohledem na možný přenos do zdravotnických zařízení.

Objective: The aim of this study was to assess the occurrence of Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA) in a university campus environment. Emphasis was placed on identifying potentially high-risk areas with frequent surface contact and high population density. Methods: Sampling was conducted at pre-selected locations across the university using sterile swab sponges. Samples were enriched in buffered peptone water (24 h, 37 °C) and subsequently cultured on selective media. The presence of SA/MRSA was confirmed using PCR. For MRSA isolates, virulence genes were detected, spa types were determined, and antimicrobial resistance was tested. Results: A total of 312 surface samples were collected from university corridors, the library, and two dining facilities. S. aureus was detected in 210 samples (67.3%). Additionally, 8 MRSA isolates were obtained (2.6%). Identified MRSA spa types included t304 (common in the Middle East), t011 belonging to the clonal lineage ST398, as well as t126 and t189. Three MRSA isolates were classified as multidrug-resistant. Conclusion: The findings highlight significant contamination of the university environment with SA and MRSA, particularly on frequently touched surfaces. The results underscore the importance of regular and targeted disinfection, appropriate selection of cleaning agents, and consistent promotion of hand hygiene among students and staff. Monitoring these pathogens may be a key tool in preventing community spread, especially considering the potential for transmission into healthcare settings.

• Keywords
• kontaminace povrchů,
• MeSH
• Fomites microbiology   MeSH
• Humans MeSH
• Methicillin-Resistant Staphylococcus aureus * isolation & purification   MeSH
• Staphylococcus aureus * isolation & purification   MeSH
• Universities * MeSH
• Environmental Exposure MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Since the incidence of vancomycin-resistant enterococci (VRE) is increasing and treatment options remain limited, we aimed to investigate the epidemiology of vancomycin- and tigecycline-resistant enterococci in a university hospital using whole genome sequencing (WGS). METHODS: Between April and December 2021, 102 VRE isolates were collected from a single tertiary care hospital in the Czech Republic. Forty selected isolates underwent antimicrobial susceptibility testing and WGS (Illumina short reads and long reads with MinION in selected isolates). RESULTS: All Enterococcus faecium isolates were resistant to ampicillin, carrying the PBP5_Met485Ala, PBP5_Glu629Val, and fluoroquinolones carrying the GyrA_Ser83Ile and ParC_Ser80Ile substitutions. The vanA operon was found on pELF2-like plasmids and plasmids carrying rep17 and/or rep18b genes. The novel Tn1546 structural variants were identified in vanA-carrying isolates. The vanB operon was located on the chromosome within a Tn1549 structural variant. Linezolid resistance was detected in one isolate carrying the 23S rDNA_G2576T substitution. Twenty-two isolates were resistant to tigecycline (tet(L), tet(M) and rpsJ_del 155-166 or RpsJ_Lys57Arg). Discrepancies between phenotypic and genotypic resistance profiles were observed for daptomycin (RpoB_Ser491Phe), trimethoprim/sulfamethoxazole (dfrG gene), nitrofurantoin (NmrA_Gln48Lys substitution without the EF0404 and EF0648 genes) and tetracycline (truncated TetM). The two multilocus sequence typing (MLST) schemes identified different numbers of STs: 5 STs, with ST117 as the predominant one (n = 32, 80%), versus 10 STs, with ST138 (27.5%), ST136 (25%), and ST1067 (20%) being the most frequent, respectively. The whole genome MLST revealed clonal clustering (0-7 allele differences) among isolates of the same ST. When comparing ST117 isolates from our study with 2,204 ST117 isolates from 15 countries, only one Czech isolate clustered closely with strains from Germany and the Netherlands, differing by just 16 alleles. CONCLUSIONS: The spread of E. faecium isolates ST117 resistant to vancomycin and tigecycline was identified. The discrepancies between resistance genotypes and phenotypes highlight the importance of combining molecular and phenotypic surveillance in antimicrobial resistance monitoring.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Bacterial Proteins genetics   MeSH
• Enterococcus faecium * genetics   drug effects   isolation & purification   classification   MeSH
• Vancomycin-Resistant Enterococci * genetics   drug effects   isolation & purification   MeSH
• Genome, Bacterial MeSH
• Gram-Positive Bacterial Infections * microbiology   epidemiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Drug Resistance, Multiple, Bacterial genetics   MeSH
• Multilocus Sequence Typing MeSH
• Vancomycin Resistance genetics   MeSH
• Whole Genome Sequencing MeSH
• Tigecycline * pharmacology   MeSH
• Vancomycin * pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

Drug resistance is a growing problem for many pathogens, including mycobacteria. Small heterocyclic molecules are among the leading scaffolds for developing potential antimycobacterial agents. Therefore, based on the molecular hybridization approach, we have prepared an extensive series of N-substituted 5-(3,5-dinitrophenyl)-1,3,4-oxadiazol-2-amine derivatives. We also investigated their isosteres and acyclic synthetic precursors. The compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis (Mtb) H37Rv, a panel of multidrug- and extensively drug-resistant Mtb isolates and two nontuberculous mycobacterial strains (NTM; M. avium and M. kansasii). The ability to inhibit mycobacterial growth was quantified using minimum inhibitory concentration (MIC) values. Many compounds achieved MIC values ≤ 0.03 μM for NTM and Mtb, regardless of their resistance profile. The highest activity was associated with oxadiazole and thiadiazole scaffolds with benzylamino or C5-C9 alkylamino substitution. The experimentally confirmed mechanism of action of these compounds consists of disruption of mycobacterial cell wall biosynthesis via inhibition of decaprenylphosphoryl-β-D-ribose 2'-epimerase (DprE1). In vitro toxicity evaluation was performed in a hepatocyte model (HepG2), while in vivo toxicity was evaluated using Danio rerio embryos. These findings identify a promising new chemotype with potent, broad-spectrum and selective antimycobacterial activity, including efficacy against resistant strains, and support its further development as a potential therapeutic candidate.

• MeSH
• Antitubercular Agents * pharmacology   chemical synthesis   chemistry   toxicity   MeSH
• Zebrafish MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Mycobacterium tuberculosis drug effects   MeSH
• Oxadiazoles * pharmacology   chemical synthesis   chemistry   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The objective of this study was to characterize the virulence characteristics of a collection of Klebsiella pneumoniae isolates collected from different clinical sources. A collection of 60 non-repetitive K. pneumoniae isolates, was studied. In vitro, virulence was analyzed by testing the survival of bacteria in pooled human serum. Isolates were typed by MLST. The genomes of 23 K. pneumoniae isolates, representatives of different STs and virulence profiles, were completely sequenced using the Illumina platform. Of note, 26/60 of K. pneumoniae isolates were resistant to killing by complement. Serum-resistant isolates belonged to distinct STs. Analysis of WGS data with VFDB showed the presence of several virulence genes related various virulence functions. Specifically, serum-resistant isolates carried a higher number of ORFs, which were associated with serum resistance, compared to serum-sensitive isolates. Additionally, analysis of WGS data showed the presence of multiple plasmid replicons that could be involved with the spread and acquisition of resistance and virulence genes. In conclusion, analysis of virulence characteristics showed that an important percentage (31.6%) of K. pneumoniae isolates were in vitro virulent by exhibiting resistance to serum. Thus, the presence of several virulence factors, in combination with the presence of multidrug resistance, could challenge antimicrobial therapy of infections caused by such bacteria.

• MeSH
• Virulence Factors * genetics   MeSH
• Genome, Bacterial MeSH
• Klebsiella Infections * microbiology   genetics   MeSH
• Klebsiella pneumoniae * genetics   pathogenicity   isolation & purification   MeSH
• Humans MeSH
• Multilocus Sequence Typing MeSH
• Hospitals MeSH
• Plasmids genetics   MeSH
• Whole Genome Sequencing MeSH
• Virulence genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Greece MeSH

The ABCB1 gene, encoding the ATP-dependent translocase ABCB1, plays a crucial role in the clearance of amyloid-beta (Aβ) peptides and the transport of cholesterol, implicating it in the pathogenesis of Alzheimer's disease. The study aims to investigate the association between polymorphisms in the ABCB1 gene and cognitive decline in individuals with mild cognitive impairment (MCI), particularly focusing on language function. A longitudinal cohort study involving 1 005 participants from the Czech Brain Aging Study was conducted. Participants included individuals with Alzheimer's disease, amnestic MCI, non-amnestic MCI, subjective cognitive decline, and healthy controls. Next-generation sequencing was utilized to analyze the entire ABCB1 gene. Cognitive performance was assessed using a comprehensive battery of neuropsychological tests, including the Boston Naming Test and the semantic verbal fluency test. Ten ABCB1 polymorphisms (rs55912869, rs56243536, rs10225473, rs10274587, rs2235040, rs12720067, rs12334183, rs10260862, rs201620488, and rs28718458) were significantly associated with cognitive performance, particularly in language decline among amnestic MCI patients. In silico analyses revealed that some of these polymorphisms may affect the binding sites for transcription factors (HNF-3alpha, C/EBPβ, GR-alpha) and the generation of novel exonic splicing enhancers. Additionally, polymorphism rs55912869 was identified as a potential binding site for the microRNA hsa-mir-3163. Our findings highlight the significant role of ABCB1 polymorphisms in cognitive decline, particularly in language function, among individuals with amnestic MCI. These polymorphisms may influence gene expression and function through interactions with miRNAs, transcription factors, and alternative splicing mechanisms.

• MeSH
• Alzheimer Disease genetics   MeSH
• Polymorphism, Single Nucleotide * MeSH
• Cognitive Dysfunction * genetics   MeSH
• Humans MeSH
• Longitudinal Studies MeSH
• Neuropsychological Tests MeSH
• ATP Binding Cassette Transporter, Subfamily B genetics   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH