Copper plays a fundamental role in aerobic metabolism, but its role is double-edged, given its toxicity. Our understanding of copper metabolism in parasites remains rudimentary, despite its significance in virulence. Here we discuss how parasitic protists control copper homeostasis and show the potential key players identified by our bioinformatic analysis.

• Klíčová slova
• bioinformatic analysis, copper, parasitic protists,
• MeSH
• Eukaryota MeSH
• faktory virulence metabolismus   MeSH
• měď metabolismus   MeSH
• paraziti * metabolismus   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktory virulence MeSH
• měď MeSH

Infection with Borrelia burgdorferi often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical conditions of Lyme disease. While our apprehension of the spatial and temporal integration of the virulence determinants during the enzootic cycle of B. burgdorferi is constantly being improved, there is still much to be discovered. Many of the novel virulence strategies discussed in this review are undetermined. Lyme disease spirochaetes must surmount numerous molecular and mechanical obstacles in order to establish a disseminated infection in a vertebrate host. These barriers include borrelial relocation from the midgut of the feeding tick to its body cavity and further to the salivary glands, deposition to the skin, haematogenous dissemination, extravasation from blood circulation system, evasion of the host immune responses, localization to protective niches, and establishment of local as well as distal infection in multiple tissues and organs. Here, the various well-defined but also possible novel strategies and virulence mechanisms used by B. burgdorferi to evade obstacles laid out by the tick vector and usually the mammalian host during colonization and infection are reviewed.

• Klíčová slova
• Borrelia burgdorferi, Lyme disease, clinical manifestations, pathogenicity, tick-borne disease, virulence determinants,
• MeSH
• Borrelia burgdorferi * genetika   MeSH
• faktory virulence MeSH
• lidé MeSH
• lymeská nemoc * MeSH
• savci MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• faktory virulence MeSH

BACKGROUND: Bacteria of the genus Enterococcus are a normal part of the intestinal microflora but also important nosocomial pathogens. An alarming fact is increasing resistance to antimicrobial agents such as vancomycin (VRE). Enterococci frequently produce numerous virulence factors, e.g. gelatinase, surface protein, adhesins and sex pheromones. Their genes, with respect to vancomycin resistance, are studied. MATERIAL AND METHODS: In 108 isolates obtained from various clinical samples (except for stools) taken from patients in the University Hospital Olomouc and divided into VRE (n = 54) and control, vancomycin-susceptible (n = 54) groups, the prevalence of genes for gelatinase (gelE), surface protein (esp) and sex pheromones (cpd, cob and ccf) was investigated. For genetic detection, real-time PCR was used. RESULTS: In the control group of vancomycin-susceptible enterococci, only six isolates (11.1 %) showed none of the studied virulence factors. The most prevalent gene was ccf (77.7 %, n = 42), followed by cpd in 66.6 % (36), gelE in 55.5 % (30), esp in 46.3 % (25) and cob in 38.9 % (21). In the VRE group, 17 isolates (31.5%) contained none of the studied genes. More prevalent was esp in 62.9 % (34), substantially less frequent were cpd in 5.6 % (3), cob in 5.6 % (3), ccf in 5.6 % (3) and gelE in 3.7 % (2). CONCLUSIONS: In VRE a smaller occurence, i.e. four out of the five studied virulence factors, were detected. The lower prevalence of genes for virulence factors was probably due to their species representation (substantially higher frequency of Enterococcus faecium in which these genes are mostly much less prevalent).

• MeSH
• Enterococcus účinky léků   genetika   metabolismus   MeSH
• faktory virulence genetika   MeSH
• lidé MeSH
• rezistence na vankomycin * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• faktory virulence MeSH

Francisella tularensis is a highly virulent intracellular pathogen with the capacity to infect a variety of hosts including humans. One of the most important proteins involved in F. tularensis virulence and pathogenesis is the protein DsbA. This protein is annotated as a lipoprotein with disulfide oxidoreductase/isomerase activity. Therefore, its interactions with different substrates, including probable virulence factors, to assist in their proper folding are anticipated. We aimed to use the immunopurification approach to find DsbA (gene locus FTS_1067) interacting partners in F. tularensis subsp. holarctica strain FSC200 and compare the identified substrates with proteins which were found in our previous comparative proteome analysis. As a result of our work two FTS_1067 substrates, D-alanyl-D-alanine carboxypeptidase family protein and HlyD family secretion protein, were identified. Bacterial two-hybrid systems were further used to test their relevance in confirming FTS_1067 protein interactions.

• Klíčová slova
• FTS_1067 protein, Francisella tularensis, bacterial two-hybrid assay, immunopurification,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• Francisella tularensis genetika   metabolismus   patogenita   MeSH
• lipoproteiny genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• lipoproteiny MeSH

American foulbrood is a quarantine disease of the honeybee Apis mellifera L. in many countries and contributes greatly to colony losses. We performed a label-free proteomics study of exoprotein fractions produced in vitro by Paenibacillus larvae reference strains of the ERIC I-IV genotypes. A quantitative comparison was performed of previous studied protein-based virulence factors and many newly identified putative virulence factors. Among the multiple proteases identified, key virulence factors included the microbial collagenase ColA and immune inhibitor A (InhA, an analog of the Bacillus thuringiensis protein InhA). Both of these virulence factors were detected in ERICs II-IV but were absent from ERIC I. Furthermore, the different S-layer proteins and polysaccharide deacetylases prevailed in ERICs II-IV. Thus, the expression patterns of these virulence factors corresponded with the different speeds at which honeybee larvae are known to be killed by ERICs II-IV compared to ERIC I. In addition, putative novel toxin-like proteins were identified, including vegetative insecticidal protein Vip1, a mosquitocidal toxin, and epsilon-toxin type B, which exhibit similarity to homologs present in Bacillus thuringiensis or Lysinibacillus sphaericus. Furthermore, a putative bacteriocin similar to Lactococcin 972 was identified in all assayed genotypes. It appears that P. larvae shares virulence factors similar to those of the Bacillus cereus group. Overall, the results provide novel information regarding P. larvae virulence potential, and a comprehensive exoprotein comparison of all four ERICs was performed for the first time. The identification of novel virulence factors can explain differences in the virulence of isolates.

• Klíčová slova
• ADP-ribosylating toxin, American foulbrood, Apis mellifera, Bacillus thuringiensis, S-layer protein, bacteriocin, immune inhibitor A, microbial collagenase ColA, mosquitocidal toxin, polysaccharide deacetylase,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• genotyp MeSH
• Paenibacillus larvae genetika   MeSH
• proteomika * MeSH
• včely mikrobiologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH

Healthcare quality improvement brings about an increasing number of invasive diagnostic and therapeutic procedures and thus also an increasing number of high-risk patients prone to hospital infections. Pseudomonas aeruginosa is one of the most commonly isolated nosocomial species and the treatment of the infection is often long and problematic, with frequent recurrences. The pathogenesis of Pseudomonas infection is associated with a range of virulence factors. In the present study, 93 catheter isolates of Pseudomonas aeruginosa were screened for the biofilm formation, motility and secretion of selected extracellular products. A high rate of the strains tested were producers of hemolysins, LasB elastase, and pyoverdines (> 70%). The biofilm formation was detected in 80% of isolates and formation of aerated biofilm was present in 90% of isolates with a positive correlation found between the two types of biofilm formation (p = 0.00583; gamma = 0.551). All strains showed swarming motility, 95% of strains showed swimming motility, and 75% of strains showed twitching motility. Among the virulence factors studied, only pyocyanin and pyochelin were produced by a lower proportion of isolates (< 25%). A positive correlation was seen between the production of some extracellular molecules (pyochelin and pyocyanin, pyocyanin and LasB elastase, and LasB elastase and haemolysins), between biofilm formation and formation of aerated biofilm, and between formation of aerated biofilm and pigments (pyoverdine and pyocyanin) production. On the other hand, a negative correlation was found between biofilm production and LasB elastase production and between the production of biofilm under immersion and pigments (pyoverdine and pyocyanin) production. All correlations are significant at the level p = 0.05, with the correlation coefficient gamma > 0.50.

• MeSH
• bakteriální proteiny analýza   MeSH
• biofilmy MeSH
• faktory virulence analýza   MeSH
• hemolyziny analýza   MeSH
• katétrové infekce mikrobiologie   MeSH
• lidé MeSH
• metaloendopeptidasy analýza   MeSH
• oligopeptidy analýza   MeSH
• pseudomonádové infekce mikrobiologie   MeSH
• Pseudomonas aeruginosa izolace a purifikace   patogenita   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• hemolyziny MeSH
• metaloendopeptidasy MeSH
• oligopeptidy MeSH
• pseudolysin, Pseudomonas aeruginosa MeSH Prohlížeč
• pyoverdin MeSH Prohlížeč

Catalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The catalase-encoding gene is conspicuously absent from the genome of most representatives of the family Trypanosomatidae. Here, we expressed this protein from the Leishmania mexicana Β-TUBULIN locus using a novel bicistronic expression system, which relies on the 2A peptide of Teschovirus A. We demonstrated that catalase-expressing parasites are severely compromised in their ability to develop in insects, to be transmitted and to infect mice, and to cause clinical manifestation in their mammalian host. Taken together, our data support the hypothesis that the presence of catalase is not compatible with the dixenous life cycle of Leishmania, resulting in loss of this gene from the genome during the evolution of these parasites.

• Klíčová slova
• Leishmania, catalase, dixeny, evolution, virulence,
• MeSH
• faktory virulence genetika   metabolismus   MeSH
• katalasa genetika   metabolismus   MeSH
• kultivované buňky MeSH
• Leishmania mexicana genetika   růst a vývoj   patogenita   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• protozoální proteiny genetika   MeSH
• Psychodidae parazitologie   MeSH
• stadia vývoje genetika   MeSH
• Teschovirus genetika   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• faktory virulence MeSH
• katalasa MeSH
• protozoální proteiny MeSH

Outer membrane vesicles (OMVs), nanoparticles released by Shiga toxin-producing Escherichia coli (STEC), have been identified as novel efficient virulence tools of these pathogens. STEC O157 OMVs carry a cocktail of virulence factors including Shiga toxin 2a (Stx2a), cytolethal distending toxin V (CdtV), EHEC hemolysin, flagellin, and lipopolysaccharide. OMVs are taken up by human intestinal epithelial and microvascular endothelial cells, the major targets during STEC infection, and deliver the virulence factors into host cells. There the toxins separate from OMVs and are trafficked via different pathways to their target compartments, i.e., the cytosol (Stx2a-A subunit), nucleus (CdtV-B subunit), and mitochondria (EHEC hemolysin). This leads to a toxin-specific host cell injury and ultimately apoptotic cell death. Besides their cytotoxic effects, STEC OMVs trigger an inflammatory response via their lipopolysaccharide and flagellin components. In this chapter, we describe methods for the isolation and purification of STEC OMVs, for the detection of OMV-associated virulence factors, and for the analysis of OMV interactions with host cells including OMV cellular uptake and intracellular trafficking of OMVs and OMV-delivered toxins.

• Klíčová slova
• Confocal laser scanning microscopy, Flow cytometry, Host cell interactions, Immunogold labeling, OMVs, Outer membrane vesicles, STEC, Shiga toxin-producing Escherichia coli, Transmission electron microscopy, Virulence cargo, Western blot,
• MeSH
• bakteriální toxiny metabolismus   MeSH
• endoteliální buňky metabolismus   mikrobiologie   patologie   MeSH
• Escherichia coli O157 * metabolismus   patogenita   MeSH
• faktory virulence metabolismus   MeSH
• lidé MeSH
• mikropartikule metabolismus   MeSH
• shiga toxin 2 metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální toxiny MeSH
• cytolethal distending toxin MeSH Prohlížeč
• faktory virulence MeSH
• shiga toxin 2 MeSH

Pseudomonas aeruginosa (PSAE) is known for its ability to form biofilm and produce other virulence factors associated with a resistant phenotype. Multidrug-resistant (MDR) PSAE strains represent a serious problem in healthcare and are the focus of an increasing number of studies dealing with the therapy of infections caused by these bacteria. Nowadays, a number of studies focus on the presence of virulence factors rather than on the mechanisms of resistance to the antibiotics used, as it is the study of virulence factors that makes it possible to expand the possibilities of effective and efficient therapy. This review describes the virulence factors produced by the one of the five PSAE secretion systems that have the potential to become targets for so-called antivirulence therapy, have been described. These are mainly alkaline protease, elastase B, exotoxins A, S and Y and pyocyanin. In addition to specific virulence factors, recent studies have focused on the components of the PSAE secretion systems that mediate the transport of toxins and lytic enzymes out of the bacterial cell. Inhibition of specific molecules for type 2 and 3 secretion systems may prevent secretion of virulence factors into the extracellular space and host cells, which would have a significant impact on reducing PSAE virulence.

• MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• biofilmy MeSH
• faktory virulence * genetika   metabolismus   farmakologie   MeSH
• pankreatická elastasa metabolismus   farmakologie   MeSH
• Pseudomonas aeruginosa * MeSH
• virulence genetika   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• faktory virulence * MeSH
• pankreatická elastasa MeSH

Nosocomial infections associated with biofilm formation have been a serious problem in recent years. Up to 32 % of them are urinary tract infections in patients with long-dwelling catheters. Catheters represent an ideal surface for bacterial adhesion, facilitating easier colonization of the urinary tract. Important pathogens causing these infections are bacteria of the genus Proteus that colonize catheters not only by biofilm formation but also using other virulence factors. Those were developed for survival in the host organism and are also used by bacteria to infect the host or fight the defence mechanisms. The study focused on the following selected virulence factors: swimming, swarming and twitching motility, swarming motility across various types of urinary catheters, biofilm formation in various media, formation of biofilm on catheters, haemolysin and urease production. A total of 102 strains isolated from urinary catheters and 50 strains isolated from stools were analyzed. In twitching motility, a difference between strains isolated from catheters and stools was statistically significant (p = 0.012). In swimming and swarming motility, the difference was not significant (p = 0.074 and p = 0.809, respectively). In motility across various catheter types, a statistically significant difference was found in strains isolated from both catheters and stools (p « 0.01 in both cases). For biofilm formation analyses, BHI and BHI with 4 % glucose were used. In BHI, biofilm was produced by all strains, with 65% of catheter strains and 88 % of strains from stools being strong producers. Similarly, all strains produced biofilm in BHI with 4 % glucose, with strong producers in 94 % and 92 % of strains isolated from catheters and stools, respectively. In formation of biofilm on catheters, there was a statistical difference between strains from catheters and stools (p = 0.00008). All strains isolated from both catheters and stools produced urease; no difference in urease production was statistically significant (p = 0.653). On agar with washed sheep erythrocytes, haemolysin production was not detected in any of the isolated strains. The quantitative method using horse erythrocytes revealed haemolysis production in three strains isolated from catheters.

• MeSH
• biofilmy MeSH
• faktory virulence analýza   MeSH
• infekce močového ústrojí mikrobiologie   MeSH
• infekce spojené se zdravotní péčí mikrobiologie   MeSH
• katetrizace močového měchýře škodlivé účinky   MeSH
• kontaminace zdravotnického vybavení MeSH
• lidé MeSH
• Proteus mirabilis izolace a purifikace   patogenita   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktory virulence MeSH