Multidrug resistant (MDR) Gram-negative bacteria have been increasingly reported in humans, companion animals and farm animals. The growing trend of plasmid-mediated resistance to antimicrobial classes of critical importance is attributed to the emergence of epidemic plasmids, rapidly disseminating resistance genes among the members of Enterobacteriaceae family. The use of antibiotics to treat humans and animals has had a significant impact on the environment and on wild animals living and feeding in human-influenced habitats. Wildlife can acquire MDR bacteria selected in hospitals, community or livestock from diverse sources, including wastewater, sewage systems, landfills, farm facilities or agriculture fields. Therefore, wild animals are considered indicators of environmental pollution by antibiotic resistant bacteria, but they can also act as reservoirs and vectors spreading antibiotic resistance across the globe. The level of resistance and reported plasmid-mediated resistance mechanisms observed in bacteria of wildlife origin seem to correlate well with the situation described in humans and domestic animals. Additionaly, the identification of epidemic plasmids in samples from different human, animal and wildlife sources underlines the role of horizontal gene transfer in the dissemination of resistance genes. The present review focuses on reports of plasmid-mediated resistance to critically important antimicrobial classes such as broad-spectrum beta-lactams and colistin in Enterobacteriaceae isolates from samples of wildlife origin. The role of plasmids in the dissemination of ESBL-, AmpC- and carbapenemase-encoding genes as well as plasmid-mediated colistin resistance determinants in wildlife are discussed, and their similarities to plasmids previously identified in samples of human clinical or livestock origin are highlighted. Furthermore, we present features of completely sequenced plasmids reported from wildlife Enterobacteriaceae isolates, with special focus on genes that could be associated with the plasticity and stable maintenance of these molecules in antibiotic-free environments.
- MeSH
- antibakteriální látky terapeutické užití MeSH
- bakteriální proteiny genetika MeSH
- beta-laktamasy genetika MeSH
- beta-laktamy terapeutické užití MeSH
- gramnegativní bakterie účinky léků genetika patogenita MeSH
- lidé MeSH
- mnohočetná bakteriální léková rezistence genetika MeSH
- plazmidy genetika MeSH
- přenos genů horizontální genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The complete nucleotide sequences of six IMP-4-encoding plasmids recovered from Enterobacteriaceae isolates of wildlife origin were characterized. Sequencing data showed that plasmids of different incompatibility groups (IncM, IncI1, IncF, and nontypeable [including an IncX5_2 and two pPrY2001-like]) carried the blaIMP-4-carrying integrons In809 or In1460. Most of the plasmids carried an mph(A) region, and chrA-like, aac(3)-IId, and blaTEM-1b genes. Finally, plasmid analysis revealed the involvement of two different IS26- and Tn1696-associated mechanisms in the mobilization of IMP-4-encoding integrons.
Antibiotická rezistence dnes představuje globální problém zdravotnictví. Nejenže se zvyšuje incidence onemocnění vyvolaných rezistentními patogenními kmeny bakterií, ale také neúměrně stoupají náklady na léčbu, prodlužuje se doba hospitalizace a nezřídka narůstá i úmrtnost. Proto je třeba při indikaci antibiotické terapie mít stále na paměti, že nadužívání, či zneužívání antibiotik přispívá k šíření genů, jež antibiotickou rezistenci kódují. Stejně tak to platí pro aplikace antibiotik ve veterinární medicíně, zemědělství včetně akvakultur nebo v potravinářském průmyslu. Genetická informace se zejména u prokaryot přenáší také horizontálně (laterálně), přímou výměnou genetického materiálu přes druhové bariéry. U nich je výměna genů nebo celých genových úseků horizontálním přenosem zcela běžná. Mohou tak dynamicky a v relativně krátkém čase vznikat vysoce rozmanité genomy, což vertikální přenos neumožňuje. Díky tomu mohou prokaryota rychle nabývat nové vlastnosti včetně virulence a patogenity, a také rezistence na toxiny včetně antibiotik, které zvyšují jejich adaptabilitu. Proto jsou reinfekce rezistentními mikroorganismy vždy obtížněji léčitelné než infekce vyvolané nerezistentními bakteriemi.
Antibiotic resistance today is a global problem of health care service. Not only does the number of diseases caused by resistant pathogenic strains of bacteria increase, but also the cost of treatment increases disproportionately, the length of hospitalization is prolonged, and mortality is often rising. Therefore, when indicating antibiotic therapy, it is important to keep in mind that both overuse and abuse of antibiotics contribute to the spread of antibiotic resistance genes. This is equally true for antibiotic applications in veterinary medicine, agriculture, including aquacultures, or in the food industry. Genetic information is in prokaryotes transmitted as well horizontally (laterally), by direct exchange of genetic material across species barriers in which the exchange of genes or whole gene segments by horizontal transmission is quite common. They can dynamically and in a relatively short time generate highly diverse genomes, which does not allow the vertical transmission. As a result, prokaryotes can rapidly acquire new properties such as virulence and pathogenicity, as well as resistance to toxins, including antibiotics, by which they increase their adaptability. Therefore, reinfection-resistant microorganisms are always more difficult to treat than infections caused by non-resistant bacteria.
Evolution has devised countless remarkable solutions to diverse challenges. Understanding the mechanistic basis of these solutions provides insights into how biological systems can be subtly tweaked without maladaptive consequences. The knowledge gained from illuminating these mechanisms is equally important to our understanding of fundamental evolutionary mechanisms as it is to our hopes of developing truly rational plant breeding and synthetic biology. In particular, modern population genomic approaches are proving very powerful in the detection of candidate alleles for mediating consequential adaptations that can be tested functionally. Especially striking are signals gained from contexts involving genetic transfers between populations, closely related species, or indeed between kingdoms. Here we discuss two major classes of these scenarios, adaptive introgression and horizontal gene flow, illustrating discoveries made across kingdoms.
The aim of this study was to characterize the first cases and outbreaks of OXA-48-like-producing Enterobacteriaceae recovered from hospital settings in the Czech Republic. From 2013 to 2015, 22 Klebsiella pneumoniae isolates, 3 Escherichia coli isolates, and 1 Enterobacter cloacae isolate producing OXA-48-like carbapenemases were isolated from 20 patients. Four of the patients were colonized or infected by two or three different OXA-48-like producers. The K. pneumoniae isolates were classified into nine sequence types (STs), with ST101 being predominant (n = 8). The E. coli isolates were of different STs, while the E. cloacae isolate belonged to ST109. Twenty-four isolates carried blaOXA-48, while two isolates carried blaOXA-181 or blaOXA-232 Almost all isolates (n = 22) carried blaOXA-48-positive plasmids of a similar size (∼60 kb), except the two isolates producing OXA-181 or OXA-232. In an ST45 K. pneumoniae isolate and an ST38 E. coli isolate, S1 nuclease profiling plus hybridization indicated a chromosomal location of blaOXA-48 Sequencing showed that the majority of blaOXA-48-carrying plasmids exhibited high degrees of identity with the pOXA-48-like plasmid pE71T. Additionally, two novel pE71T derivatives, pOXA-48_30715 and pOXA-48_30891, were observed. The blaOXA-181-carrying plasmid was identical to the IncX3 plasmid pOXA181_EC14828, while the blaOXA-232-carrying plasmid was a ColE2-type plasmid, being a novel derivative of pOXA-232. Finally, sequencing data showed that the ST45 K. pneumoniae and ST38 E. coli isolates harbored the IS1R-based composite transposon Tn6237 containing blaOXA-48 integrated into their chromosomes. These findings underlined that the horizontal transfer of pOXA-48-like plasmids has played a major role in the dissemination of blaOXA-48 in the Czech Republic. In combination with the difficulties with their detection, OXA-48 producers constitute an important public threat.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální chromozomy genetika MeSH
- bakteriální proteiny genetika metabolismus MeSH
- beta-laktamasy genetika metabolismus MeSH
- Enterobacteriaceae účinky léků enzymologie genetika MeSH
- Escherichia coli účinky léků enzymologie genetika MeSH
- Klebsiella pneumoniae účinky léků enzymologie genetika MeSH
- mikrobiální testy citlivosti MeSH
- plazmidy genetika MeSH
- přenos genů horizontální genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Stable endosymbiosis of a bacterium into a host cell promotes cellular and genomic complexity. The mealybug Planococcus citri has two bacterial endosymbionts with an unusual nested arrangement: the γ-proteobacterium Moranella endobia lives in the cytoplasm of the β-proteobacterium Tremblaya princeps These two bacteria, along with genes horizontally transferred from other bacteria to the P. citri genome, encode gene sets that form an interdependent metabolic patchwork. Here, we test the stability of this three-way symbiosis by sequencing host and symbiont genomes for five diverse mealybug species and find marked fluidity over evolutionary time. Although Tremblaya is the result of a single infection in the ancestor of mealybugs, the γ-proteobacterial symbionts result from multiple replacements of inferred different ages from related but distinct bacterial lineages. Our data show that symbiont replacement can happen even in the most intricate symbiotic arrangements and that preexisting horizontally transferred genes can remain stable on genomes in the face of extensive symbiont turnover.
- MeSH
- Betaproteobacteria genetika růst a vývoj MeSH
- fylogeneze MeSH
- Gammaproteobacteria genetika růst a vývoj MeSH
- genom bakteriální MeSH
- Planococcus (hmyz) genetika mikrobiologie MeSH
- přenos genů horizontální genetika MeSH
- sekvenční analýza DNA MeSH
- symbióza genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Current dogma holds that genes are the property of individual mammalian cells and partition between daughter cells during cell division. However, and rather unexpectedly, recent research has demonstrated horizontal cell-to-cell transfer of mitochondria and mitochondrial DNA in several mammalian cell culture systems. Furthermore, unequivocal evidence that mitochondrial DNA transfer occurs in vivo has now been published. While these studies show horizontal transfer of mitochondrial DNA in pathological settings, it is also possible that intercellular mitochondrial transfer is a fundamental physiological process with a role in development and tissue homeostasis.
- MeSH
- buněčné dělení genetika MeSH
- lidé MeSH
- mezibuněčná komunikace genetika MeSH
- mitochondriální DNA genetika MeSH
- mitochondrie genetika MeSH
- přenos genů horizontální genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Archamoebae is an understudied group of anaerobic free-living or endobiotic protists that constitutes the major anaerobic lineage of the supergroup Amoebozoa. Hitherto, the phylogeny of Archamoebae was based solely on SSU rRNA and actin genes, which did not resolve relationships among the main lineages of the group. Because of this uncertainty, several different scenarios had been proposed for the phylogeny of the Archamoebae. In this study, we present the first multigene phylogenetic analysis that includes members of Pelomyxidae, and Rhizomastixidae. The analysis clearly shows that Mastigamoebidae, Pelomyxidae and Rhizomastixidae form a clade of mostly free-living, amoeboid flagellates, here called Pelobiontida. The predominantly endobiotic and aflagellated Entamoebidae represents a separate, deep-branching lineage, Entamoebida. Therefore, two unique evolutionary events, horizontal transfer of the nitrogen fixation system from bacteria and transfer of the sulfate activation pathway to mitochondrial derivatives, predate the radiation of recent lineages of Archamoebae. The endobiotic lifestyle has arisen at least three times independently during the evolution of the group. We also present new ultrastructural data that clarifies the primary divergence among the family Mastigamoebidae which had previously been inferred from phylogenetic analyses based on SSU rDNA.
- MeSH
- Archamoebae klasifikace genetika metabolismus ultrastruktura MeSH
- fixace dusíku genetika MeSH
- fylogeneze * MeSH
- mitochondrie metabolismus MeSH
- molekulární evoluce MeSH
- multigenová rodina genetika MeSH
- přenos genů horizontální genetika MeSH
- sírany metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The influence of specific and non-specific antibiotic pressure on in vivo spread of macrolide-lincosamide-streptogramin B (MLSB) resistance was evaluated in this study. Chickens repeatedly inoculated with Enterococcus faecalis harbouring the plasmid pAMβ1 carrying the erm(B) gene were perorally treated for one week with tylosin, lincomycin (both specific antibiotic pressure) and chlortetracycline (non-specific antibiotic pressure). Antibiotic non-treated but E. faecalis inoculated chickens served as a control. To quantify the erm(B) gene and characterise intestinal microflora, faecal DNA was analysed by qPCR and 454-pyrosequencing. Under the pressure of antibiotics, a significant increase in erm(B) was observed by qPCR. However, at the final stage of the experiment, an increase in erm(B) was also observed in two out of five non-treated chickens. In chickens treated with tylosin and chlortetracycline, the increase in erm(B) was accompanied by an increase in enterococci. However, E. faecalis was at the limit of detection in all animals. This suggests that the erm(B) gene spread among the gut microbiota other than E. faecalis. Pyrosequencing results indicated that, depending on the particular antibiotic pressure, different bacteria could be responsible for the spread of MLSB resistance. Different species of MLSB-resistant enterococci and streptococci were isolated from cloacal swabs during and after the treatment. PFGE analysis of MLSB-resistant enterococci revealed four clones, all differing from the challenge strain. All of the MLSB-resistant isolates harboured a plasmid of the same size as pAMβ1. This study has shown that MLSB resistance may spread within the gut microbiota under specific and non-specific pressure and even in the absence of any antimicrobial pressure. Finally, depending on the particular antibiotic pressure, different bacterial species seems to be involved in the spread of MLSB resistance.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- chlortetracyklin farmakologie MeSH
- DNA primery genetika MeSH
- druhová specificita MeSH
- Enterococcus faecalis účinky léků genetika MeSH
- feces mikrobiologie MeSH
- grampozitivní bakteriální infekce veterinární MeSH
- kur domácí * MeSH
- linkosamidy farmakologie MeSH
- makrolidy farmakologie MeSH
- methyltransferasy genetika MeSH
- mikrobiální testy citlivosti MeSH
- molekulární sekvence - údaje MeSH
- nemoci drůbeže mikrobiologie MeSH
- neparametrická statistika MeSH
- plazmidy genetika MeSH
- polymerázová řetězová reakce veterinární MeSH
- přenos genů horizontální genetika MeSH
- pulzní gelová elektroforéza veterinární MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- streptogramin B farmakologie MeSH
- tylosin farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Among the bacteria groups, most of them are known to be beneficial to human being whereas only a minority is being recognized as harmful. The pathogenicity of bacteria is due, in part, to their rapid adaptation in the presence of selective pressures exerted by the human host. In addition, through their genomes, bacteria are subject to mutations, various rearrangements or horizontal gene transfer among and/or within bacterial species. Bacteria's essential metabolic functions are generally encoding by the core genes. Apart of the core genes, there are several number of mobile genetic elements (MGE) acquired by horizontal gene transfer that might be beneficial under certain environmental conditions. These MGE namely bacteriophages, transposons, plasmids, and pathogenicity islands represent about 15% Staphylococcus aureus genomes. The acquisition of most of the MGE is made by horizontal genomic islands (GEI), recognized as discrete DNA segments between closely related strains, transfer. The GEI contributes to the wide spread of microorganisms with an important effect on their genome plasticity and evolution. The GEI are also involve in the antibiotics resistance and virulence genes dissemination. In this review, we summarize the mobile genetic elements of S. aureus.
- MeSH
- bakteriální chromozomy genetika MeSH
- bakteriofágy genetika MeSH
- genomové ostrovy genetika MeSH
- lidé MeSH
- přenos genů horizontální genetika MeSH
- rozptýlené repetitivní sekvence genetika MeSH
- Staphylococcus aureus genetika MeSH
- transpozibilní elementy DNA genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
