Coagulase-negative staphylococci (CoNS) are an important cause of human and animal diseases. Treatment of these diseases is complicated by their common antimicrobial resistance, caused by overuse of antibiotics in hospital and veterinary environment. Therefore, they are assumed to serve as a reservoir of resistance genes often located on plasmids. In this study, we analyzed plasmid content in 62 strains belonging to 10 CoNS species of human and veterinary origin. In 48 (77%) strains analyzed, 107 different plasmids were detected, and only some of them showed similarities with plasmids found previously. In total, seven different antimicrobial-resistance genes carried by plasmids were identified. Five of the CoNS staphylococci carried plasmids identical with either those of other CoNS species tested, or a well characterized Staphylococcus aureus strain COL, suggesting plasmid dissemination through horizontal transfer. To demonstrate the possibility of horizontal transfer, we performed electroporation of four resistance plasmids among Staphylococcus epidermidis, Staphylococcus petrasii, and coagulase-positive S. aureus strains. Plasmids were transferred unchanged, were stably maintained in recipient strains, and expressed resistance genes. Our work demonstrates a great variability of plasmids in human and veterinary staphylococcal strains and their ability to maintain and express resistance plasmids from other staphylococcal species.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- genetická variace * MeSH
- koagulasa MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- plazmidy účinky léků genetika MeSH
- přenos genů horizontální MeSH
- stafylokokové infekce MeSH
- Staphylococcus aureus genetika MeSH
- Staphylococcus účinky léků enzymologie genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lytic bacteriophages are valuable therapeutic agents against bacterial infections. There is continual effort to obtain new phages to increase the effectivity of phage preparations against emerging phage-resistant strains. Here we described the genomic diversity of spontaneous host-range mutants of kayvirus 812. Five mutant phages were isolated as rare plaques on phage-resistant Staphylococcus aureus strains. The host range of phage 812-derived mutants was 42% higher than the wild type, determined on a set of 186 methicillin-resistant S. aureus strains representing the globally circulating human and livestock-associated clones. Comparative genomics revealed that single-nucleotide polymorphisms from the parental phage 812 population were fixed in next-step mutants, mostly in genes for tail and baseplate components, and the acquired point mutations led to diverse receptor binding proteins in the phage mutants. Numerous genome changes associated with rearrangements between direct repeat motifs or intron loss were found. Alterations occurred in host-takeover and terminal genomic regions or the endolysin gene of mutants that exhibited the highest lytic activity, which implied various mechanisms of overcoming bacterial resistance. The genomic data revealed that Kayvirus spontaneous mutants are free from undesirable genes and their lytic properties proved their suitability for rapidly updating phage therapeutics.
- MeSH
- bakteriální léková rezistence MeSH
- bakteriofágy genetika MeSH
- délka genomu MeSH
- genom virový MeSH
- genomika MeSH
- jednonukleotidový polymorfismus MeSH
- methicilin farmakologie MeSH
- mutace * MeSH
- Staphylococcus aureus růst a vývoj virologie MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Staphylococcus aureus je významný oportunní patogen a častý původce bakteriálních nozokomiálních nákaz.Patogenní vlastnosti této bakterie jsou často kódovány mobilními genetickými elementy, jako jsou např. plazmi-dy. Na plazmidu se nachází i gen etb pro exfoliativní toxin B (ETB), který je příčinou puchýřnatého onemocnění(bulózní impetigo), jehož generalizovaná a život ohrožující forma se označuje jako stafylokokový syndrom opařené kůže. U pěti etb-pozitivních plazmidů, izolovaných během let 1999–2015 z kmenů S. aureus pocházejícíchz českých nemocnic, byla provedena srovnávací sekvenční analýza. Bylo zjištěno, že velká většina z nich sdílírozsáhlou oblast sekvence DNA, která zahrnuje typické geny virulence, avšak obsahují i variabilní úseky umož-ňující jejich diferenciaci. Přestože se dosud předpokládalo, že jsou ETB plazmidy relativně uniformní, byl izolo-ván a popsán nový typ, který s ostatními ETB plazmidy vykazuje jen minimální sekvenční shodu. Nese navíc geny pro horizontální přenos konjugací a nové varianty genů pro faktory virulence včetně etb, čímž reprezentuje zcela novou linii plazmidů kódujících exfoliatin B.
Staphylococcus aureus is an important opportunistic pathogen and a common cause of bacterial nosocomialinfections. Pathogenic properties of this bacterium are often encoded by mobile genetic elements, such as plas-mids. Plasmids also carry the etb gene encoding exfoliative toxin B(ETB), which is the cause of ablistering disease(bullous impetigo)whose generalized and life-threatening form is known as staphylococcal scalded skin syn-drome. Comparative sequence analysis was conducted to study five etb-positive plasmids, isolated from S. aureusstrains from Czech hospitals between 1999 and 2015. They were found to share a large part of the DNA sequencecomprising typical virulence genes. However, they also contain variable fragments, which help us to differentiatebetween them. Although ETB plasmids were previously assumed to be relatively uniform, a new type showingminimal sequence similarity to other ETB plasmids was isolated and described. Moreover, it carries genes forhorizontal transfer by conjugation as well as new variants of genes for virulence factors, including etb, and assuch it represents a completely new lineage of exfoliative toxin B-encoding plasmids.
Exfoliative toxin B (ETB) encoded by some large plasmids plays a crucial role in epidermolytic diseases caused by Staphylococcus aureus. We have found as yet unknown types of etb gene-positive plasmids isolated from a set of impetigo strains implicated in outbreaks of pemphigus neonatorum in Czech maternity hospitals. Plasmids from the strains of clonal complex CC121 were related to archetypal plasmid pETBTY4. Sharing a 33-kb core sequence including virulence genes for ETB, EDIN C, and lantibiotics, they were assigned to a stand-alone lineage, named pETBTY4-based plasmids. Differing from each other in the content of variable DNA regions, they formed four sequence types. In addition to them, a novel unique plasmid pETB608 isolated from a strain of ST130 was described. Carrying conjugative cluster genes, as well as new variants of etb and edinA genes, pETB608 could be regarded as a source of a new lineage of ETB plasmids. We have designed a helpful detection assay, which facilitates the precise identification of the all described types of ETB plasmids.
- MeSH
- bakteriální proteiny genetika MeSH
- bakteriociny genetika MeSH
- dermotoxiny genetika MeSH
- DNA bakterií genetika MeSH
- exfoliatiny genetika MeSH
- fylogeneze MeSH
- impetigo epidemiologie mikrobiologie MeSH
- lidé MeSH
- pemfigus epidemiologie mikrobiologie MeSH
- plazmidy genetika izolace a purifikace MeSH
- sekvenování celého genomu MeSH
- Staphylococcus aureus klasifikace genetika MeSH
- virulence genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
Exfoliative toxin A (ETA)-coding temperate bacteriophages are leading contributors to the toxic phenotype of impetigo strains of Staphylococcus aureus. Two distinct eta gene-positive bacteriophages isolated from S. aureus strains which recently caused massive outbreaks of pemphigus neonatorum in Czech maternity hospitals were characterized. The phages, designated φB166 and φB236, were able to transfer the eta gene into a prophageless S. aureus strain which afterwards converted into an ETA producer. Complete phage genome sequences were determined, and a comparative analysis of five designed genomic regions revealed major variances between them. They differed in the genome size, number of open reading frames, genome architecture, and virion protein patterns. Their high mutual sequence similarity was detected only in the terminal regions of the genome. When compared with the so far described eta phage genomes, noticeable differences were found. Thus, both phages represent two new lineages of as yet not characterized bacteriophages of the Siphoviridae family having impact on pathogenicity of impetigo strains of S. aureus.
- MeSH
- DNA virů chemie genetika MeSH
- DNA viry genetika izolace a purifikace MeSH
- epidemický výskyt choroby MeSH
- exfoliatiny genetika MeSH
- fylogeneze MeSH
- genom virový * MeSH
- impetigo epidemiologie mikrobiologie MeSH
- infekce spojené se zdravotní péčí epidemiologie MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- novorozenec MeSH
- otevřené čtecí rámce MeSH
- polymorfismus délky restrikčních fragmentů MeSH
- pořadí genů MeSH
- porodnice MeSH
- přenos genů horizontální MeSH
- profágy klasifikace genetika izolace a purifikace MeSH
- sekvenční analýza DNA MeSH
- sekvenční homologie MeSH
- shluková analýza MeSH
- stafylokokové bakteriofágy klasifikace genetika izolace a purifikace MeSH
- stafylokokové infekce epidemiologie mikrobiologie MeSH
- Staphylococcus aureus izolace a purifikace virologie MeSH
- syntenie MeSH
- transdukce genetická MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Staphylococcus aureus is one of the most frequent pathogens infecting the respiratory tract of patients with cystic fibrosis (CF). This study was the first to examine S. aureus isolates from CF patients in the Czech Republic. Among 100 S. aureus isolates from 92 of 107 observed patients, we found a high prevalence of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (56%). More than half of the resistant strains (29 of 56) carried a mutation in the MLS(B) target site. The emergence of MLS(B) resistance and mutations conferring resistance to MLS(B) antibiotics was associated with azithromycin treatment (p=0.000000184 and p=0.000681, respectively). Methicillin resistance was only detected in 3% of isolates and the rate of resistance to other antibiotics did not exceed 12%. The prevalence of small-colony variant (SCV) strains was relatively low (9%) and eight of nine isolates with the SCV phenotype were thymidine dependent. The study population of S. aureus was heterogeneous in structure and both the most prevalent community-associated and hospital-acquired clonal lineages were represented. Of the virulence genes, enterotoxin genes seg (n=52), sei (n=49), and sec (n=16) were the most frequently detected among the isolates. The PVL genes (lukS-PV and lukF-PV) have not been revealed in any of the isolates.
- MeSH
- antibakteriální látky farmakologie terapeutické užití MeSH
- azithromycin terapeutické užití MeSH
- bakteriální léková rezistence genetika MeSH
- cystická fibróza mikrobiologie MeSH
- dlouhodobá péče MeSH
- infekce spojené se zdravotní péčí mikrobiologie MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- mutace genetika MeSH
- ribozomy genetika MeSH
- stafylokokové infekce farmakoterapie mikrobiologie MeSH
- Staphylococcus aureus účinky léků genetika MeSH
- thymidin genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
