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

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

Rare and unknown actinobacteria from unexplored environments have the potential to produce new bioactive molecules. This study aimed to use 16 s rRNA metabarcoding to determine the composition of the actinobacterial community, particularly focusing on rare and undescribed species, in a nature reserve within the Brazilian Cerrado called Sete Cidades National Park. Since this is an inaccessible area without due legal authorization, it is understudied, and, therefore, its diversity and biotechnological potential are not yet fully understood, and it may harbor species with groundbreaking genetic potential. In total, 543 operational taxonomic units (OTUs) across 14 phyla were detected, with Actinobacteria (41.2%), Proteobacteria (26.5%), and Acidobacteria (14.3%) being the most abundant. Within Actinobacteria, 107 OTUs were found, primarily from the families Mycobacteriaceae, Pseudonocardiaceae, and Streptomycetaceae. Mycobacterium and Streptomyces were the predominant genera across all samples. Seventeen rare OTUs with relative abundance < 0.1% were identified, with 82.3% found in only one sample yet 25.5% detected in all units. Notable rare and transient genera included Salinibacterium, Nocardia, Actinomycetospora_01, Saccharopolyspora, Sporichthya, and Nonomuraea. The high diversity and distribution of Actinobacteria OTUs indicate the area's potential for discovering new rare species. Intensified prospection on underexplored environments and characterization of their actinobacterial diversity could lead to the discovery of new species capable of generating innovative natural products.

• MeSH
• Actinobacteria * chemistry   classification   genetics   isolation & purification   MeSH
• Biodiversity MeSH
• Metagenome MeSH
• Soil chemistry   MeSH
• Soil Microbiology * MeSH
• RNA, Ribosomal, 16S analysis   MeSH
• DNA Barcoding, Taxonomic MeSH
• Parks, Recreational MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Brazil 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

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

OBJECTIVES: To analyse characteristics of Clostridioides difficile PCR ribotype 176 clinical isolates from Poland, the Czech Republic and Slovakia with regard to the differences in its epidemiology. METHODS: Antimicrobial susceptibility testing and whole genome sequencing were performed on a selected group of 22 clonally related isolates as determined by multilocus variable-number tandem repeat analysis (n = 509). Heterologous expression and functional analysis of the newly identified methyltransferase were performed. RESULTS: Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (gyrA_p. T82I), aminoglycosides with aac(6')-Ie-aph(2'')-Ia in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with ermB gene. Fourteen isolates were resistant to rifampicin with rpoB_p. R505K or p. R505K/H502N, and five to imipenem with pbp1_p. P491L and pbp3_p. N537K. PnimBG together with nimB_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The cfrE, vanZ1 and cat-like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The ermB gene was carried by new Tn7808, Tn6189 and Tn6218-like. The aac(6')-Ie-aph(2'')-Ia were carried by Tn6218-like and new Tn7806 together with cfrE gene. New Tn7807 carried a cat-like gene. Tn6110 and new Tn7806 contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without ermB gene. CONCLUSIONS: Multidrug-resistant C. difficile PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in C. difficile was identified.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Drug Resistance, Bacterial * MeSH
• Bacterial Proteins genetics   MeSH
• Clostridioides difficile * genetics   drug effects   isolation & purification   classification   MeSH
• Genomic Islands * MeSH
• Clostridium Infections * microbiology   epidemiology   MeSH
• Humans MeSH
• Methyltransferases genetics   MeSH
• Microbial Sensitivity Tests MeSH
• Drug Resistance, Multiple, Bacterial * genetics   MeSH
• Multilocus Sequence Typing MeSH
• Ribotyping MeSH
• Whole Genome Sequencing MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Poland MeSH

UNLABELLED: The paper presents the study of a set of isolates of Streptococcus pneumoniae, which comprised two heterogeneous subpopulations, one of which was susceptible and the other resistant to optochin. The aim of the study was to compare the results of serotyping, multilocus sequence typing (MLST), ribosomal multilocus sequence typing (rMLST), and variation analysis of these subpopulations and to investigate the genetic probable causes of optochin resistance. The strains studied were cultured from samples taken from patients with invasive pneumococcal disease in the Czech Republic in 2019 and 2020. A total of 10 studied pairs of isolates were subject to serotyping and whole-genome sequencing (WGS). None of the typing methods (serotyping, MLST, or rMLST) applied to pairs of optochin-susceptible and optochin-resistant isolates revealed differences in serotype, sequence type, or ribosomal sequence type. The WGS data analysis identified point mutations in ATP (adenosine triphosphate) synthase genes in 8 of the 10 optochin-resistant isolates. In seven optochin-resistant isolates, the mutation was found in the atpC gene and in one isolate in the atpA gene. One of the mutations in the atpC gene has not yet been published in the literature; it is a mutation at position 143T > C with an amino acid change of Val48Ala. In 8 out of the 10 optochin-resistant isolates, the possible genetic basis for resistance was identified, involving point mutations in the atpA and atpC genes. In the remaining two isolates, no clear genetic explanation for the optochin resistance in S. pneumoniae was found, based on current knowledge. IMPORTANCE: Globally, among the most fundamental tests used for the identification of Streptococcus pneumoniae isolates is determining susceptibility to optochin. In the last 2 decades, optochin-resistant strains have been frequently reported in the literature, which can lead to the misidentification of S. pneumoniae. This study compares whole-genome sequencing data of optochin-susceptible and optochin-resistant subpopulations of S. pneumoniae isolates and investigates the genetic probable causes of resistance in the genomes of optochin-resistant subpopulations.

• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Drug Resistance, Bacterial * genetics   MeSH
• Bacterial Proteins genetics   MeSH
• Quinine analogs & derivatives   MeSH
• Genome, Bacterial MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Multilocus Sequence Typing MeSH
• Pneumococcal Infections microbiology   MeSH
• Whole Genome Sequencing MeSH
• Serotyping MeSH
• Streptococcus pneumoniae * genetics   drug effects   isolation & purification   classification   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Geographicals
• Czech Republic MeSH

Although Campylobacter jejuni is the pathogen responsible for the most common foodborne illness, tracing of the infection source remains challenging due to its highly variable genome. Therefore, one of the aim of the study was to compare three genotyping methods (MLST, PFGE, and mP-BIT) to determine the most effective genotyping tool. C. jejuni strains were divided into 4 clusters based on strain similarity in the cgMLST dendrogram. Subsequently, the dendrograms of the 3 tested methods were compared to determine the accuracy of each method compared to the reference cgMLST method. Moreover, a cost-benefit analysis has showed that MLST had the highest inverse discrimination index (97%) and required less workflow, time, fewer consumables, and low bacterial sample quantity. PFGE was shown to be obsolete both because of its low discriminatory power and the complexity of the procedure. Similarly, mP‐BIT showed low separation results, which was compensated by its high availability. Therefore, our data showed that MLST is the optimal tool for genotyping C. jejuni. Another aim was to compare the antimicrobial resistance to ciprofloxacin, erythromycin, and tetracycline in C. jejuni strains isolated from human, water, air, food, and animal samples by two gene sequence-based prediction methods and to compare them with the actual susceptibility of C. jejuni strains using the disc diffusion method. Both tools, ResFinder and RGI, synchronously predict the antimicrobial susceptibility of C. jejuni and either can be used.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Drug Resistance, Bacterial genetics   MeSH
• Campylobacter jejuni * genetics   MeSH
• Genotype MeSH
• Campylobacter Infections * microbiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Multilocus Sequence Typing MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The main aim of this study was to determine expanded sequence types (eSTs) of Ureaplasma species (U. spp.). DNA isolated from the amniotic fluid of pregnancies complicated by preterm prelabor rupture of membranes (PPROM) using an expanded multilocus sequence typing scheme. Additionally, the study sought to examine whether phylogenetic subgroups of U. spp. DNA differ with respect to maternal demographic and clinical parameters and selected aspects of short-term neonatal morbidity. This retrospective cohort study was focused on singleton pregnancies complicated by PPROM occurring between the gestational ages of 24+0 and 36+6 weeks, where amniocentesis was conducted to assess the intra-amniotic environment and the presence of U. spp. DNA in the amniotic fluid samples was confirmed. The stored aliquots of U. spp. DNA were used to assess differences in nucleotide sequences in six U. spp. genes (ftsH, rpL22, valS, thrS,ureG, and mba-np1) using the eMLST scheme. The expanded multilocus sequence typing scheme was performed in 73 samples of U. spp. DNA isolated from pregnancies complicated by PPROM. In total, 33 different U. spp. DNA eSTs were revealed, 21 (#20, 233-244, 248-251, 253, 255, 259, and 262) of which were novel. The most frequently identified eST was #41, identified in 18% (13/73) of the aliquots. Based on their genetic relationships, the U. spp. DNA was divided into two clusters and four subgroups [cluster I (U. parvum): A, 43% (n = 31); B, 15% (n = 11); and C, 26% (n = 19); cluster II (U. urealyticum): 1; 16% (n = 12)]. Cluster II had a higher rate of polymicrobial findings than cluster I (58% vs 16%; p = 0.005), while subgroup A had the highest rate of concomitant Mycoplasma hominis in the amniotic fluid samples (66%; p = 0.04). In conclusion, Ureaplasma spp. DNA obtained from PPROM consisted of 33 different eSTs of U. spp. DNA. No differences in maternal and neonatal characteristics were found among the phylogenetical subgroups of U. spp. DNA, except for a higher rate of polymicrobial amniotic fluid findings in those with U. urealyticumand the concomitant presence of M. hominis in the amniotic fluid in those with the presence of U. parvum.

• MeSH
• DNA, Bacterial analysis   genetics   MeSH
• Adult MeSH
• Phylogeny MeSH
• Gestational Age MeSH
• Pregnancy Complications, Infectious microbiology   MeSH
• Humans MeSH
• Multilocus Sequence Typing * MeSH
• Amniotic Fluid * microbiology   MeSH
• Fetal Membranes, Premature Rupture * microbiology   MeSH
• Retrospective Studies MeSH
• Pregnancy MeSH
• Ureaplasma * genetics   isolation & purification   MeSH
• Ureaplasma Infections * microbiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

• MeSH
• Molecular Targeted Therapy MeSH
• Humans MeSH
• Molecular Typing * MeSH
• Mutation * genetics   drug effects   MeSH
• Carcinoma, Non-Small-Cell Lung * diagnosis   drug therapy   genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH