BACKGROUND: For many years, syphilis treatment was considered straightforward due to the universal susceptibility of Treponema pallidum subsp. pallidum (TPA) to penicillin antibiotics. METHODS: Penicillin-binding protein genes from a ceftriaxone treatment failure T. pallidum isolate were assessed, and the introduction of identified mutations into two laboratory strains via natural competence was aimed for, followed by in vitro analysis of antibiotic susceptibility of the recombinants. RESULTS: TPA from the ceftriaxone treatment failure case contained A1873G and G2122A mutations in the TP0705 gene. Introduction of the A1873G mutation into laboratory strains DAL-1 and SS14 resulted in partial resistance to ceftriaxone and penicillin G in vitro. Furthermore, in silico analyses revealed that the majority of contemporary TPA SS14-like strains harbors this mutation and are thus partially resistant to ceftriaxone and penicillin G. CONCLUSIONS: This finding indicates that TPA strains accumulate mutations that increase their resistance to β-lactam antibiotics. Alternative approaches for controlling syphilis will be needed, including the development of the syphilis vaccine.
Penicillin antibiotics have been used to treat syphilis since the 1950s. Resistance to antibiotics is a growing concern. We investigated cases where antibiotics had failed to treat infection and found two mutations in a specific gene that could be responsible. Introduction of one of these mutations into two laboratory T. pallidum strains (the bacteria that cause syphilis) resulted in partial resistance to both ceftriaxone and penicillin antibiotics. Moreover, analysis of existing data revealed the presence of this mutation in numerous circulating T. pallidum strains, suggesting widespread partial resistance may already exist and increasing concerns about the future emergence of fully resistant syphilis strains.
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: Treponema pallidum subsp. pallidum (T. pallidum) is the etiological agent of syphilis, a sexually transmitted disease of global public health importance. The objective of this study was to introduce a novel in vitro protocol for isolation of T. pallidum directly from patients' clinical samples, eliminating the need for rabbit propagation. METHODS: Four oral and five genital swabs were collected from nine epidemiologically unrelated patients at two hospitals in Brno, Czech Republic. Swabs were submerged in TpCM-2 medium for transport. Samples were then placed on a 0.4 μm filters and incubated for 2.5 hours. During this period, spiral T. pallidum cells passed through the filter pores to the well containing TpCM-2 medium and rabbit feeder cells (Sf1Ep). Stable T. pallidum cultures (containing >1 × 107 treponemes) were achieved by subculturing every 7 days into fresh well. RESULTS: A successful protocol for in vitro isolation of T. pallidum was established. From the nine clinical specimens processed, six T. pallidum cultures (MU1-MU6) were derived after 14 to 112 days of cultivation. Five of these strains (MU1-MU5) belonged to SS14-like cluster and shared the same allelic profile 1.3.1. The remaining strain (MU6) was identified as a Nichols-like strain with an allelic profile 9.16.3. DISCUSSION: The introduced in vitro protocol enables isolation of T. pallidum from clinical material, including frozen samples, without the need for experimental rabbits. This method facilitates the isolation of contemporary, clinically relevant treponemal strains.
- Klíčová slova
- Contemporary isolates, In vitro isolation, Spirochetes, Syphilis, Treponema pallidum,
- MeSH
- bakteriologické techniky * metody MeSH
- králíci MeSH
- lidé MeSH
- pohlavní orgány mikrobiologie MeSH
- syfilis * mikrobiologie diagnóza MeSH
- Treponema pallidum * izolace a purifikace genetika klasifikace MeSH
- ústa mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Taylorella equigenitalis is the causative agent of sexually transmitted contagious equine metritis. Infections manifest as cervicitis, vaginitis and endometritis and cause temporary infertility and miscarriages of mares. While previous studies have analyzed this organism for various parameters, the evolutionary dynamics of this pathogen, including the emergence of antibiotic resistance, remains unresolved. The aim of this study was to isolate contemporary strains, determine their genome sequences, evaluate their antibiotic resistance and compare them with other strains. We determined nine complete whole genome sequences of T. equigenitalis strains, mainly from samples collected from Kladruber horses in the Czech Republic. While T. equigenitalis strains from Kladruby isolated between 1982 and 2018 were inhibited by streptomycin, contemporary strains were found to be resistant to streptomycin, suggesting the recent emergence of this mutation. In addition, we used the collection dates of Kladruber horse strains to estimate the genome substitution rate, which resulted in a scaled mean evolutionary rate of 6.9×10-7 substitutions per site per year. Analysis with other available T. equigenitalis genome sequences (n = 18) revealed similarity of the Czech T. equigenitalis genomes with the Austrian T. equigenitalis genome, and molecular dating suggested a common ancestor of all analyzed T. equigenitalis strains from 1.5-2.6 thousand years ago, dating to the first centuries A.D. Our study revealed a recently emerged streptomycin resistance in T. equigenitalis strains from Kladruber horses, emphasizing the need for antibiotic surveillance and alternative treatments. Additionally, our findings provided insights into the pathogen's evolution rate, which is important for understanding its evolution and preparing preventive strategies.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- fylogeneze MeSH
- genom bakteriální * genetika MeSH
- koně mikrobiologie MeSH
- molekulární evoluce MeSH
- nemoci koní * mikrobiologie MeSH
- sekvenování celého genomu * MeSH
- Taylorella equigenitalis * genetika MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- antibakteriální látky MeSH
In this work, we determined that Treponema pallidum subsp. pallidum (TPA) DAL-1 (belonging to Nichols-like group of TPA strains) grew 1.53 (± 0.08) times faster compared to TPA Philadelphia 1 (SS14-like group) during in vitro cultivations. In longitudinal individual propagation in rabbit testes (n = 12, each TPA strain), infection with DAL-1 manifested clinical symptoms (induration, swelling, and erythema of testes) sooner than Philadelphia 1 infection, which resulted in a significantly shorter period of the experimental passages for DAL-1 (median = 15.0 and 23.5 days, respectively; p < 0.01). To minimize the confounding conditions during rabbit experiments, the growth characteristics of DAL-1 and Philadelphia 1 strains were determined during TPA co-infection of rabbit testes (n = 20, including controls). During two weeks of intratesticular co-infection, DAL-1 overgrew Philadelphia 1 in all twelve testes, regardless of inoculation ratio and dose (median of relative excess DAL-1 multiplication = 84.85×). Moreover, higher DAL-1 to Philadelphia 1 inoculum ratios appeared to increase differences in growth rates, suggesting direct competition between strains for available nutrients during co-infection. These experiments indicate important physiological differences between the two TPA strains and suggest growth differences between Nichols-like and SS14-like strains that are potentially linked to their virulence and pathogenicity.
- MeSH
- králíci MeSH
- syfilis mikrobiologie patologie MeSH
- testis mikrobiologie metabolismus MeSH
- Treponema pallidum * MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The complete genome sequences of five Escherichia coli strains with probiotic attributes were determined, including strain A0 34/86, a component of the probiotic product Colinfant New Born, and strains H22, 582, B771, and B1172 with published probiotic potential. The size of sequenced genomes ranged from 5,092 to 5,408 kb.
- Klíčová slova
- Escherichia, Escherichia coli, probiotics,
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Pathogenic strains of Escherichia coli have been clearly identified as the causative agents of extraintestinal and diarrheal infections; however, the etiopathogenic role of E. coli in other conditions, including colorectal cancer, remains unclear. METHODS: This study aimed to characterize mucosal E. coli isolates (n = 246) from 61 neoplasia patients and 20 healthy controls for the presence of 35 genetic determinants encoding known virulence factors. RESULTS: Virulence determinants encoding invasin (ibeA), siderophore receptor (iroN), S-fimbriae (sfa), and genotoxin (usp) were more prevalent among E. coli isolated from patients with neoplasia compared to the control group (p < 0.05). In addition, the prevalence of these virulence determinants was increased in more advanced neoplasia stages (p adj < 0.0125). Compared to patients with advanced colorectal adenoma and carcinoma, the ibeA gene was rarely found in the control group and among patients with non-advanced adenoma (p < 0.05), indicating its potential as the advanced-neoplasia biomarker. Patients with neoplasia frequently had E. coli strains with at least one of the abovementioned virulence factors, whereby specific combinations of these virulence factors were found. DISCUSSION: These findings suggest that E. coli strains isolated from patients with colorectal neoplasia possess several virulence factors, which could contribute to the development of neoplastic processes in the large intestine.
- Klíčová slova
- Escherichia coli, cancer, colorectal neoplasia, genotoxin, ibeA, invasion, virulence factors,
- Publikační typ
- časopisecké články MeSH
Fonticins are phage tail-like bacteriocins produced by the Gram-negative bacterium Pragia fontium from the family Budviciaceae. This bacterium produces contractile-type particles that adsorb on the surface of sensitive bacteria and penetrate the cell wall, probably during contraction, in a way similar to the type VI secretion system. We characterized the pore-forming activity of fonticins using both living cells and in vitro model membranes. Using a potassium leakage assay, we show that fonticins are able to permeabilize sensitive cells. On black lipid membranes, single-pore conductance is about 0.78 nS in 1 M NaCl and appears to be linearly dependent on the increasing molar strength of NaCl solution, which is a property of considerably large pores. In agreement with these findings, fonticins are not ion selective for Na+, K+, and Cl-. Polyethylene glycol 3350 (PEG 3350) molecules of about 3.5 nm in diameter can enter the fonticin pore lumen, whereas the larger molecules cannot pass the pore. The size of fonticin pores was confirmed by transmission electron microscopy. The terminal membrane-piercing complex of the fonticin tube probably creates a selective barrier restricting passage of macromolecules. IMPORTANCE Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins. According to some theories, related particles were initially adapted for passage of double-stranded DNA (dsDNA) molecules, but fonticins changed their function during the evolution; they are able to form large pores through the bacterial envelope of Gram-negative bacteria. As various pore-forming proteins are extensively used for nanopore sequencing and stochastic sensing, we decided to investigate the pore-forming properties of fonticin protein complexes on artificial lipid membranes. Our research revealed remarkable structural properties of these particles that may have a potential application as a nanodevice.
- Klíčová slova
- black lipid membranes, conductance, electric current, electron microscopy, fonticin, membrane pore formation, phage tail-like bacteriocins, single-pore conductance,
- MeSH
- bakteriociny * metabolismus MeSH
- buněčná membrána metabolismus MeSH
- chlorid sodný metabolismus MeSH
- Enterobacteriaceae MeSH
- Gammaproteobacteria MeSH
- lipidové dvojvrstvy * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bakteriociny * MeSH
- chlorid sodný MeSH
- lipidové dvojvrstvy * MeSH
Exploratory mass spectrometry-based metabolomics generates a plethora of features in a single analysis. However, >85% of detected features are typically false positives due to inefficient elimination of chimeric signals and chemical noise not relevant for biological and clinical data interpretation. The data processing is considered a bottleneck to unravel the translational potential in metabolomics. Here, we describe a systematic workflow to refine exploratory metabolomics data and reduce reported false positives. We applied the feature filtering workflow in a case/control study exploring common variable immunodeficiency (CVID). In the first stage, features were detected from raw liquid chromatography-mass spectrometry data by XCMS Online processing, blank subtraction, and reproducibility assessment. Detected features were annotated in metabolomics databases to produce a list of tentative identifications. We scrutinized tentative identifications' physicochemical properties, comparing predicted and experimental reversed-phase liquid chromatography (LC) retention time. A prediction model used a linear regression of 42 retention indices with the cLogP ranging from -6 to 11. The LC retention time probes the physicochemical properties and effectively reduces the number of tentatively identified metabolites, which are further submitted to statistical analysis. We applied the retention time-based analytical feature filtering workflow to datasets from the Metabolomics Workbench (www.metabolomicsworkbench.org), demonstrating the broad applicability. A subset of tentatively identified metabolites significantly different in CVID patients was validated by MS/MS acquisition to confirm potential CVID biomarkers' structures and virtually eliminate false positives. Our exploratory metabolomics data processing workflow effectively removes false positives caused by the chemical background and chimeric signals inherent to the analytical technique. It reduced the number of tentatively identified metabolites by 88%, from initially detected 6940 features in XCMS to 839 tentative identifications and streamlined consequent statistical analysis and data interpretation.
- MeSH
- biologické markery MeSH
- chromatografie kapalinová MeSH
- lidé MeSH
- metabolomika * MeSH
- reprodukovatelnost výsledků MeSH
- tandemová hmotnostní spektrometrie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
Enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing E. coli (STEC) strains are the causative agents of severe foodborne diseases in both humans and animals. In this study, porcine pathogenic E. coli strains (n = 277) as well as porcine commensal strains (n = 188) were tested for their susceptibilities to 34 bacteriocin monoproducers to identify the most suitable bacteriocin types inhibiting porcine pathogens. Under in vitro conditions, the set of pathogenic E. coli strains was found to be significantly more susceptible to the majority of tested bacteriocins than commensal E. coli. Based on the production of bacteriocins with specific activity against pathogens, three potentially probiotic commensal E. coli strains of human origin were selected. These strains were found to be able to outcompete ETEC strains expressing F4 or F18 fimbriae in liquid culture and also decreased the severity and duration of diarrhea in piglets during experimental ETEC infection as well as pathogen numbers on the last day of in vivo experimentation. While the extents of the probiotic effect were different for each strain, the cocktail of all three strains showed the most pronounced beneficial effects, suggesting synergy between the tested E. coli strains. IMPORTANCE Increasing levels of antibiotic resistance among bacteria also increase the need for alternatives to conventional antibiotic treatment. Pathogenic Escherichia coli represents a major diarrheic infectious agent of piglets in their postweaning period; however, available measures to control these infections are limited. This study describes three novel E. coli strains producing antimicrobial compounds (bacteriocins) that actively inhibit a majority of toxigenic E. coli strains. The beneficial effect of three potentially probiotic E. coli strains was demonstrated under both in vitro and in vivo conditions. The novel probiotic candidates may be used as prophylaxis during piglets' postweaning period to overcome common infections caused by E. coli.
- Klíčová slova
- E. coli, ETEC, Escherichia, STEC, bacteriocin, pig, probiotic,
- MeSH
- bakteriální toxiny * metabolismus MeSH
- bakteriociny metabolismus terapeutické užití MeSH
- Escherichia coli * účinky léků genetika metabolismus MeSH
- faktory virulence genetika MeSH
- feces mikrobiologie MeSH
- infekce vyvolané Escherichia coli mikrobiologie prevence a kontrola veterinární MeSH
- nemoci prasat mikrobiologie prevence a kontrola MeSH
- prasata MeSH
- probiotika terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie veterinární MeSH
- Názvy látek
- bakteriální toxiny * MeSH
- bakteriociny MeSH
- faktory virulence MeSH
Common variable immunodeficiency (CVID) is a clinically and genetically heterogeneous disorder with inadequate antibody responses and low levels of immunoglobulins including IgA that is involved in the maintenance of the intestinal homeostasis. In this study, we analyzed the taxonomical and functional metagenome of the fecal microbiota and stool metabolome in a cohort of six CVID patients without gastroenterological symptomatology and their healthy housemates. The fecal microbiome of CVID patients contained higher numbers of bacterial species and altered abundance of thirty-four species. Hungatella hathewayi was frequent in CVID microbiome and absent in controls. Moreover, the CVID metagenome was enriched for low-abundance genes likely encoding nonessential functions, such as bacterial motility and metabolism of aromatic compounds. Metabolomics revealed dysregulation in several metabolic pathways, mostly associated with decreased levels of adenosine in CVID patients. Identified features have been consistently associated with CVID diagnosis across the patients with various immunological characteristics, length of treatment, and age. Taken together, this initial study revealed expansion of bacterial diversity in the host immunodeficient conditions and suggested several bacterial species and metabolites, which have potential to be diagnostic and/or prognostic CVID markers in the future.
- Klíčová slova
- CVID, Hungatella hathewayi, common variable immunodeficiency, metabolome, metagenome, microbiome,
- MeSH
- adenosin metabolismus MeSH
- běžná variabilní imunodeficience genetika mikrobiologie MeSH
- biodiverzita MeSH
- Clostridiaceae fyziologie MeSH
- dysbióza genetika mikrobiologie MeSH
- feces mikrobiologie MeSH
- homeostáza MeSH
- lidé MeSH
- metabolomika MeSH
- metagenom MeSH
- RNA ribozomální 16S genetika MeSH
- střevní mikroflóra genetika MeSH
- výpočetní biologie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenosin MeSH
- RNA ribozomální 16S MeSH
