Methods for Natural Transformation in Acinetobacter baumannii

Wilharm, Gottfried; Skiebe, Evelyn

doi:10.1007/978-1-4939-9118-1_8

Cited by 7 publications

(3 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, the plasmid sequence analysis failed to identify any plasmid transfer operons. Other mechanisms, including natural transformation, transduction, and/or outer membrane vesicle (OMV)mediated transfer, may contribute to the HGT of this plasmid (17)(18)(19), which deserves further study. Nevertheless, our study clearly demonstrated that these antibioticresistant plasmids or strains are spreading in waterfowls and their neighboring environments in China.…”

Section: Discussionmentioning

confidence: 99%

Co-occurrence of Plasmid-Mediated Tigecycline and Carbapenem Resistance in Acinetobacter spp. from Waterfowls and Their Neighboring Environment

Cui

Chen

Liu

et al. 2020

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Tigecycline serves as one of the antibiotics of last resort to treat multidrug-resistant (including carbapenem-resistant) pathogens. However, the recently emerged plasmid-mediated tigecycline resistance mechanism, Tet(X), challenges the clinical efficacy of this class of antibiotics. In this study, we detected 180 tet(X)-harboring Acinetobacter isolates (8.9%, n = 180) from 2,018 samples collected from avian farms and adjacent environments in China. Eighteen tet(X)-harboring isolates (10.0%) were found to cocarry the carbapenemase gene blaNDM-1, mostly from waterfowl samples (94.4%, 17/18). Interestingly, among six Acinetobacter strains, tet(X) and blaNDM-1 were found to colocalize on the same plasmids. Moreover, whole-genome sequencing (WGS) revealed a novel orthologue of tet(X) in the six isolates coharboring tet(X) and blaNDM-1. Inverse PCR suggested that the two tet(X) genes form a single transposable unit and may be cotransferred. Sequence comparison between six tet(X)- and blaNDM-1-coharboring plasmids showed that they shared a highly homologous plasmid backbone even though they were isolated from different Acinetobacter species (three from Acinetobacter indicus, two from Acinetobacter schindleri, and one from Acinetobacter lwoffii) from various sources and from different geological regions, suggesting the horizontal genetic transfer of a common tet(X)- and blaNDM-1-coharboring plasmid among Acinetobacter species in China. Emergence and spread of such plasmids and strains are of great clinical concern, and measures must be implemented to avoid their dissemination.

show abstract

Section: Discussionmentioning

confidence: 99%

Co-occurrence of Plasmid-Mediated Tigecycline and Carbapenem Resistance in Acinetobacter spp. from Waterfowls and Their Neighboring Environment

Cui

Chen

Liu

et al. 2020

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…However, transforming protocols vary wildly between studies (13)(14)(15), including the use of different solidifying agents for transformation scoring on surfaces (16). Additionally, only few isolates of this species, such as the strains A118 (13) and M2 (recently reclassified as A. nosocomialis) (15,17), were previously found to be naturally competent, though recent studies are showing that a plethora of clinical and wildlife/livestock A. baumannii isolates are likewise naturally transformable (12,14,18).…”

Section: Introductionmentioning

confidence: 99%

Pilus Production in Acinetobacter baumannii Is Growth Phase Dependent and Essential for Natural Transformation

Vesel

Blokesch

2021

J Bacteriol

View full text Add to dashboard Cite

Acinetobacter baumannii is a severe threat to human health as a frequently multidrug-resistant hospital-acquired pathogen. Part of the danger from this bacterium comes from its genome plasticity and ability to evolve quickly by taking up and recombining external DNA into its own genome in a process called natural competence for transformation. This mode of horizontal gene transfer is one of the major ways pathogens can acquire new antimicrobial resistances and toxic traits. Because these processes in A. baumannii are not well studied, we herein characterized new aspects of natural transformability in this species that include the species’ competence window. We uncovered a strong correlation with a growth–phase-dependent synthesis of a type IV pilus (TFP), which constitutes the central part of competence-induced DNA-uptake machinery. We used bacterial genetics and microscopy to demonstrate that the TFP is essential for the natural transformability and surface motility of A. baumannii, whereas pilus-unrelated proteins of the DNA-uptake complex do not impact the motility phenotype. Furthermore, TFP biogenesis and assembly is subject to input from two regulatory systems that are homologous to Pseudomonas aeruginosa, namely the PilSR two-component system and the Pil-Chp chemosensory system. We demonstrated that these systems not only impact the piliation status of cells but also their ability to take up DNA for transformation. Importantly, we report on discrepancies between TFP biogenesis and natural transformability within the same genus by comparing A. baumannii to data reported for A. baylyi, the latter of which served for decades as a model for natural competence. IMPORTANCE Rapid bacterial evolution has alarming negative impacts on animal and human health, which can occur when pathogens acquire antimicrobial resistance traits. As a major cause of antibiotic-resistant opportunistic infections, A. baumannii is a high priority health threat, which has motivated renewed interest in studying how this pathogen acquires new, dangerous traits. In this study, we deciphered a specific time window in which these bacteria can acquire new DNA, and correlated that with its ability to produce the external appendages that contribute to the DNA acquisition process. These cell appendages function doubly for motility on surfaces and for DNA uptake. Collectively, we showed that A. baumannii is similar in its TFP production to Pseudomonas aeruginosa, though differs from the well-studied species A. baylyi.

show abstract

“…Hence, nests become huge and bulky over time as the result of an accumulation of sticks, twigs, straw, and hay, as well as, sometimes, anthropogenic material such as twine, rags, plastic foil, and paper ( Vergara et al 2010 ; Jagiello et al 2018 ). Such re-used nests, along with the accumulated feces of many individuals, are suitable environments for microbial growth (e.g., Wilharm et al 2017 ; Wilharm and Skiebe 2019 ). Moreover, the white stork is a foraging opportunist ( Kosicki et al 2006 ) using anthropogenic sources of food such as landfill ( Tortosa et al 2002 ).…”

mentioning

confidence: 99%

Not so black, not so white: differences in microorganism load of contiguous feathers from white stork chicks

et al. 2020

View full text Add to dashboard Cite

Many organisms are characterised by strikingly contrasting black and white colouration, but the function of such contrasts has been inadequately studied. In the present paper, we tested the function of black and white contrasting plumage in white stork Ciconia ciconia chicks. We found greater abundance and diversity of microorganisms on black compared to adjacent white feathers. In addition, nest size was positively correlated with the abundance and diversity of microorganisms on white feathers. Flight initiation distance (FID), defined as the distance at which adult white storks took flight when approached by a human, was negatively correlated with most measurements of microorganism abundance. Breeding success was generally positively correlated with the abundance and diversity of microorganisms on black feathers. The feather growth rate was positively correlated with some and negatively correlated with other measurements of microbial abundance and diversity. Finally, chick growth was negatively correlated with the number of microbial species on black feathers and positively with the abundance and diversity of microorganisms on white feathers. These findings are consistent not only with the role of microorganisms in the maintenance of a benign microbial environment which differs between black and white feathers, but also with the hypothesis that several taxa of microorganisms found in black and white plumage are virulent, with negative effects on the fitness of their hosts.

show abstract

Methods for Natural Transformation in Acinetobacter baumannii

Cited by 7 publications

References 40 publications

Co-occurrence of Plasmid-Mediated Tigecycline and Carbapenem Resistance in Acinetobacter spp. from Waterfowls and Their Neighboring Environment

Co-occurrence of Plasmid-Mediated Tigecycline and Carbapenem Resistance in Acinetobacter spp. from Waterfowls and Their Neighboring Environment

Pilus Production in Acinetobacter baumannii Is Growth Phase Dependent and Essential for Natural Transformation

Not so black, not so white: differences in microorganism load of contiguous feathers from white stork chicks

Contact Info

Product

Resources

About