The aim of this study is to evaluate opportunistic pathogenic bacteria of the genus Pseudomonas in anthropogenically impacted bathing waters, primarily focusing on bathing ponds. The findings include the detection of these bacteria, their susceptibility to selected antibiotics, and the determination of the Exotoxin A (exoA) gene using PCR method. P. aeruginosa was present in most samples, albeit in low concentrations (1-14 CFU/100 mL). The presence of P. otitidis, which is associated with ear infection, in this type of bathing water, was not rare (up to 90 CFU/100 mL). This species would not be detected by the standard methods, including tests on acetamid medium, used for P. aeruginosa in water. The isolated strains of P. otitidis lack the exoA gene and exhibited higher resistance to meropenem compared to P. aeruginosa.
- MeSH
- ADP Ribose Transferases genetics MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Drug Resistance, Bacterial MeSH
- Bacterial Proteins genetics MeSH
- Bacterial Toxins genetics MeSH
- Pseudomonas aeruginosa Exotoxin A MeSH
- Exotoxins genetics MeSH
- Virulence Factors genetics MeSH
- Microbial Sensitivity Tests * MeSH
- Water Microbiology * MeSH
- Polymerase Chain Reaction MeSH
- Pseudomonas * genetics isolation & purification classification drug effects MeSH
- Ponds * microbiology 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 present study has undertaken the isolation of marine yeasts from mangrove sediment samples and their ability to produce alkaline protease enzymes. A total of 14 yeast isolates were recovered on yeast-malt agar (YMA) and yeast extract peptone dextrose (YEPD) agar medium. After screening for proteolytic activity on skim milk agar, marine yeast isolate, AKB-1 exhibited a hydrolysis zone of 18 mm. Optimal conditions for the enzyme production from yeast isolate AKB-1 were at 30 °C, pH 8, fructose as carbon source, potassium nitrate as nitrogen source, and 25% saline concentration. Under the optimal conditions, the protease enzyme activity of the isolate AKB-1 was observed to be 978 IU/mL. The structural and functional analysis was carried out through FTIR and HPLC analysis for the extracted protease enzyme. Furthermore, the enzyme produced was partially purified by solvent extraction using ethyl acetate and ammonium sulfate precipitation (3.4-fold) followed by dialysis (56.8-fold). The molecular weight of the purified enzyme was observed to be around 60 kDa using SDS-PAGE. The extracted protein showed good antibacterial activity against six different clinical bacterial pathogens and the highest against Bacillus cereus (16 ± 0.5 mm). The extracted protease enzyme was revealed to remove blood stains from cloth within 20 min of application similar to the commercial detergent. The marine yeast isolate was further identified as Candida orthopsilosis AKB-1 (Accession number KY348766) through 18S rRNA sequencing, and a phylogenetic tree was generated.
- MeSH
- Anti-Bacterial Agents pharmacology metabolism chemistry isolation & purification MeSH
- Bacillus cereus drug effects MeSH
- Bacterial Proteins * chemistry pharmacology metabolism isolation & purification MeSH
- Candida * enzymology isolation & purification genetics classification MeSH
- Endopeptidases * chemistry metabolism isolation & purification pharmacology MeSH
- Phylogeny MeSH
- Geologic Sediments microbiology MeSH
- Hydrogen-Ion Concentration MeSH
- Culture Media chemistry MeSH
- Microbial Sensitivity Tests MeSH
- Molecular Weight MeSH
- Enzyme Stability MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
Escherichia coli is a significant pathogen in extraintestinal infections, and ESBL-producing E. coli poses a major clinical challenge due to its antibiotic resistance. This study comprehensively analyzed E. coli isolates from urine and blood samples of patients with urinary tract and bloodstream infections at three major tertiary hospitals in South Korea. The goal was to provide insights into the distribution, antibiotic resistance, and virulence factors of these strains. Our analysis identified CTX-M and TEM as the dominant ESBL types, found in 71.7% and 61.7% of isolates, respectively, with 46.7% showing co-occurrence. Multilocus sequence typing (MLST) revealed the predominance of high-risk clones such as ST131, ST69, ST73, and ST95, with rare sequence types like ST410 and ST405 also identified. The high prevalence of virulence factors, including iutA (80.8%) and kpsMII (74.2%), further highlights the complexity of these strains. In addition, 38.3% of clinical isolates contained a combination of siderophore, adhesin, protectin, and toxin-related genes. There was no significant difference between urinary tract and bloodstream infections or regional differentiation in Korea. This study highlights the importance of controlling ESBL-producing E. coli infections, especially given the increasing incidence among patients with underlying medical conditions and older adults who are more susceptible to urinary tract infections. These findings serve as valuable indicators for pathogen analysis, especially those harboring antibiotic resistance and toxin genes. The insights gained are expected to contribute significantly to the development of infectious disease prevention and control strategies.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Bacteremia * microbiology epidemiology MeSH
- beta-Lactamases * genetics metabolism MeSH
- Adult MeSH
- Escherichia coli * genetics isolation & purification pathogenicity enzymology drug effects classification MeSH
- Virulence Factors genetics MeSH
- Urinary Tract Infections * microbiology epidemiology MeSH
- Escherichia coli Infections * microbiology epidemiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Young Adult MeSH
- Multilocus Sequence Typing MeSH
- Prevalence MeSH
- Escherichia coli Proteins genetics metabolism MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Virulence MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Republic of Korea MeSH
In 2019, Pantoea piersonii was initially isolated from the interior surfaces of the International Space Station. This microorganism is a species within the genus Pantoea in the family Erwiniaceae, belonging to the order Enterobacterales. Recent literature has documented four cases of its isolation. Despite initial predictions suggesting the non-pathogenicity of P. piersonii strains, evidence from observed cases indicates potential pathogenicity. According to documented evidence in the literature, this microorganism is capable of causing severe and life-threatening conditions, including sepsis. Traditional tests, as well as automated systems, may fail to provide complete differentiation due to these similarities. While MALDI-TOF MS is a valuable tool for identification in clinical diagnostic microbiology, sequencing may be necessary for precise identification. To determine the antibiotic susceptibility profile, various methods can be utilized, including minimum inhibitory concentration determination, disk diffusion testing (Kirby-Bauer test), genotypic resistance assays (PCR and sequencing), and automated systems. The literature reports a limited number of cases associating P. piersonii with human infection. This study contributes to this body of knowledge by reporting a novel case in which P. piersonii was isolated from a tissue sample for the first time. In this case report, the patient achieved recovery following the administration of appropriate antibiotic treatment based on the diagnosis. It underscores the need for precise identification and understanding of its pathogenicity.
- MeSH
- Anti-Bacterial Agents * pharmacology therapeutic use MeSH
- Enterobacteriaceae Infections * microbiology diagnosis drug therapy MeSH
- Humans MeSH
- Microbial Sensitivity Tests * MeSH
- Pantoea * isolation & purification genetics pathogenicity MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
BackgroundOn 29 January 2024, the European Centre for Disease Prevention and Control distributed an alert about a metronidazole-resistant Clostridioides difficile outbreak of PCR ribotype (RT) 955 in England.AimWe aimed to investigate the presence of RT955 in Czech, Slovak and Polish C. difficile isolates and evaluate different culture media for detecting its metronidazole resistance.MethodsIsolates with binary toxin genes identified as 'unknown' by the WEBRIBO PCR ribotyping database up to 2023 were re-analysed after adding the RT955 profile to the database. The RT955 isolates were characterised by whole genome sequencing and tested for susceptibility to 15 antimicrobials.ResultsWe did not find RT955 in Czech (n = 6,661, 2012-2023) and Slovak (n = 776, 2015-2023) isolates, but identified 13 RT955 cases (n = 303, 2021-2023) in three hospitals in Poland. By whole genome multilocus sequence typing, 10 isolates clustered into one clonal complex including a sequence of United Kingdom strain ERR12670107, and shared similar antimicrobial resistance genes/mutations. All 13 isolates were resistant to ciprofloxacin/moxifloxacin, erythromycin/clindamycin and ceftazidime. All isolates had a mutation in the nimB gene promoter and in NimB (Tyr130Ser and Leu155Ile). The metronidazole resistance was detected in all isolates using brain-heart-infusion agar supplemented with haemin and Chocolate agar. Results were discrepant with the European Committee on Antimicrobial Susceptibility Testing-recommended Fastidious anaerobe agar and Brucella blood agar.ConclusionThe identification of clonally related haem-dependent metronidazole-resistant C. difficile RT955 in multiple hospitals indicates a need for prospective surveillance to estimate its prevalence in Europe.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Drug Resistance, Bacterial * genetics MeSH
- Clostridioides difficile * genetics drug effects isolation & purification classification MeSH
- Disease Outbreaks MeSH
- Clostridium Infections * epidemiology microbiology drug therapy MeSH
- Humans MeSH
- Metronidazole * pharmacology MeSH
- Microbial Sensitivity Tests MeSH
- Multilocus Sequence Typing MeSH
- Polymerase Chain Reaction MeSH
- Ribotyping * MeSH
- Whole Genome Sequencing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- Poland MeSH
- Slovakia MeSH
Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia are considered emerging pathogens classified as a public health problem due to extensive antimicrobial resistance. Therefore, the discovery of new therapeutic strategies has become crucial. This study aimed to evaluate the antimicrobial activity of gallic acid and methyl gallate against non-fermenting bacteria. The study included five clinical isolates of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia. The minimum inhibitory concentrations of gallic acid and methyl gallate were determined by the broth microdilution method. Growth curves, metabolic activity, and biofilm formation of each bacterial strain in the presence or absence of phenolic compounds were performed. Finally, the therapeutic efficacy of the compounds was evaluated using an in vivo model. Gallic acid and methyl gallate showed antibacterial activity against bacterial strains in a concentration range of 64 to 256 μg/mL, both compounds reduced bacterial growth and metabolic activity of the strains, even at subinhibitory concentrations. Only, methyl gallate exhibited activity to inhibit the formation of bacterial biofilms. Moreover, gallic acid and methyl gallate increased larval survival by up to 60% compared to 30% survival of untreated larvae in a bacterial infection model in Galleria mellonella. Our results highlight the potential of gallic acid and methyl gallate as therapeutic alternatives for infections by emerging non-fermentative bacteria.
Current antibiotics and chemotherapeutics are becoming ineffective because pathogenic bacteria and tumor cells have developed multiple drug resistance. Therefore, it is necessary to find new substances that can be used in treatment, either alone or as sensitizing molecules in combination with existing drugs. Peptaibols are bioactive, membrane-active peptides of non-ribosomal origin, mainly produced by filamentous fungi such as Trichoderma spp. This study focused on producing peptaibol-rich extracts from Trichoderma atroviride O1, cultivated on malt extract agar (MA) under circadian and constant darkness conditions for 13 days. Peptaibol production was detected by MALDI-TOF mass spectrometry after six days of cultivation. The extracts demonstrated antibacterial activity against Staphylococcus aureus strains, particularly the methicillin-resistant variant, but not against the Gram-negative Pseudomonas aeruginosa. Quorum sensing interference revealed that a peptaibol-rich extract suppressed Vibrio campbellii BAA-1119's AI-2 signaling system to a degree comparable with gentamycin. Beyond antibacterial properties, the extracts exhibited notable antiproliferative activity against human ovarian cancer cells and their adriamycin-resistant subline in both 2D and 3D models. Specifically, MA-derived extracts reduced ovarian cancer cell viability by 70% at 50 μg/mL, especially under light/dark regime of cultivation. Compared to previously published results for PDA-based extracts, MA cultivation shifted the biological effects of peptaibol-containing extracts toward anticancer potential. These findings support the idea that modifying fungal cultivation parameters, the bioactivity of secondary metabolite mixtures can be tailored for specific therapeutic applications.
- MeSH
- Agar * chemistry MeSH
- Anti-Bacterial Agents * pharmacology metabolism MeSH
- Hypocreales MeSH
- Culture Media chemistry MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Cell Line, Tumor MeSH
- Peptaibols * pharmacology metabolism biosynthesis chemistry MeSH
- Cell Proliferation drug effects MeSH
- Antineoplastic Agents * pharmacology metabolism MeSH
- Pseudomonas aeruginosa drug effects MeSH
- Staphylococcus aureus drug effects MeSH
- Trichoderma * metabolism growth & development chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Antibiogram představuje základní nástroj pro správnou volbu antibiotické terapie v klinické praxi. Jedná se o stěžejní pilíř antibiotického stewardshipu, který díky spolupráci mezi klinickým mikrobiologem a ošetřujícím lékařem umožňuje dosažení optimálních léčebných výsledků u bakteriálních infekcí, minimalizaci nežádoucích účinků, prevenci rozvoje antibiotické rezistence a ekonomickou efektivitu léčby. Tento přehledový článek shrnuje různé typy antibiogramů, možnosti jejich stanovení a současně se zaměřuje na problematiku interpretace a praktického využití antibiogramů v každodenní klinické praxi.
The antibiogram is a fundamental diagnostic instrument for the appropriate selection and optimization of antimicrobial therapy in clinical practice. It is an essential component of antibiotic stewardship, which, through collaboration between clinical microbiologists and treating physicians, enables optimal treatment outcomes in bacterial infections, minimization of adverse effects, prevention of antibiotic resistance development, and cost-effective treatment. This review article summarizes various antibiogram methodologies and their determination procedures, with particular emphasis on the interpretation and practical implementation of antibiograms in routine clinical practice.
- MeSH
- Anti-Bacterial Agents pharmacology therapeutic use MeSH
- Bacteria drug effects MeSH
- Drug Resistance, Bacterial MeSH
- Humans MeSH
- Microbial Sensitivity Tests * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review 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
