scholarly journals Interspecies DNA acquisition by a naturally competentAcinetobacter baumanniistrain

2018 ◽  
Author(s):  
German M. Traglia ◽  
Kori Place ◽  
Cristian Dotto ◽  
Jennifer S. Fernandez ◽  
Camila dos Santos Bahiense ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Human Pathogen ◽  
Whole Genome Analysis ◽  
Resistance Level ◽  
Resistance Determinants ◽  
Carbapenem Resistant ◽  
Multiple Resistance Genes

ABSTRACTAcinetobacter baumanniiis a human pathogen that frequently acquires antibiotic resistance genes leading to the emergence of multi-drug-resistant (MDR) strains. To investigate the role of transformation in the acquisition of resistance determinants by this species, the susceptible strain A118 was exposed to genomic DNA of carbapenem-resistantKlebsiella pneumoniae(CRKp). Resistant transformants were obtained and an increase in the resistance level to all β-lactam antibiotics was observed. Whole genome analysis of transformant clones demonstrated the acquisition of CRKp DNA. The most frequently acquired genes correspond to mobile elements, antibiotic resistance genes, and operons involved in metabolism. Bioinformatic analyses andin silicogene flow prediction strengthen our findings, showing that a continuing exchange of genetic material betweenA. baumanniiandK. pneumoniaeoccurs when they share the same niche. Our results reinforce the idea that natural transformation may play a key role in the increasing emergence ofA. baumanniiMDR.IMPORTANCESince the characterization of antibiotic resistance in the late ‘50s, antibiotic resistance propagation was classically associated with horizontal gene transfer (HGT) mediated by plasmids bearing multiple resistance genes. Here we show that, at least in the human pathogenA. baumannii, transformation also plays a major role in the acquisition of antibiotic resistance determinants. This study unravels that at least for certain pathogens the propagation of resistance genes occurs by alternative HGT mechanisms which in the past have been unappreciated.

scholarly journals Correlation between the Antibiotic Resistance Genes and Susceptibility to Antibiotics among the Carbapenem-Resistant Gram-Negative Pathogens

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 255
Author(s):  
Salma M. Abdelaziz ◽  
Khaled M. Aboshanab ◽  
Ibrahim S. Yahia ◽  
Mahmoud A. Yassien ◽  
Nadia A. Hassouna
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multiple Drug ◽  
P Value ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Gram Negative ◽  
Carbapenem Resistant

In this study, the correlation between the antibiotic resistance genes and antibiotic susceptibility among the carbapenem-resistant Gram-negative pathogens (CRGNPs) recovered from patients diagnosed with acute pneumonia in Egypt was found. A total of 194 isolates including Klebsiella pneumoniae (89; 46%), Escherichia coli (47; 24%) and Pseudomonas aeruginosa (58; 30%) were recovered. Of these, 34 (18%) isolates were multiple drug resistant (MDR) and carbapenem resistant. For the K. pneumoniae MDR isolates (n = 22), blaNDM (14; 64%) was the most prevalent carbapenemase, followed by blaOXA-48 (11; 50%) and blaVIM (4; 18%). A significant association (p value < 0.05) was observed between the multidrug efflux pump (AcrA) and resistance to β-lactams and the aminoglycoside acetyl transferase gene (aac-6’-Ib) gene and resistance to ciprofloxacin, azithromycin and β-lactams (except for aztreonam). For P. aeruginosa, a significant association was noticed between the presence of the blaSHV gene and the multidrug efflux pump (MexA) and resistance to fluoroquinolones, amikacin, tobramycin, co-trimoxazole and β-lactams and between the aac-6’-Ib gene and resistance to aminoglycosides. All P. aeruginosa isolates (100%) harbored the MexAB-OprM multidrug efflux pump while 86% of the K. pneumoniae isolates harbored the AcrAB-TolC pump. Our results are of great medical importance for the guidance of healthcare practitioners for effective antibiotic prescription.

scholarly journals The Influencing Factors of Bacterial Resistance Related to Livestock Farm: Sources and Mechanisms

2021 ◽  
Vol 2 ◽  
Author(s):  
Kaixuan Guo ◽  
Yue Zhao ◽  
Luqing Cui ◽  
Zhengzheng Cao ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Influencing Factors ◽  
Resistance Genes ◽  
Bacterial Resistance ◽  
Genetic Material ◽  
Resistance Mechanism ◽  
Antibiotic Resistance Genes ◽  
Direct Selection ◽  
Adaptive Mutation ◽  
Specific Response

Bacterial resistance is a complex scientific issue. To manage this issue, we need to deeply understand the influencing factors and mechanisms. Based on the background of livestock husbandry, this paper reviews the factors that affect the acquisition of bacterial resistance. Meanwhile, the resistance mechanism is also discussed. “Survival of the fittest” is the result of genetic plasticity of bacterial pathogens, which brings about specific response, such as producing adaptive mutation, gaining genetic material or changing gene expression. To a large extent, bacterial populations acquire resistance genes directly caused by the selective pressure of antibiotics. However, mobile resistance genes may be co-selected by other existing substances (such as heavy metals and biocides) without direct selection pressure from antibiotics. This is because the same mobile genetic elements as antibiotic resistance genes can be co-located by the resistance determinants of some of these compounds. Furthermore, environmental factors are a source of resistance gene acquisition. Here, we describe some of the key measures that should be taken to mitigate the risk of antibiotic resistance. We call on the relevant governments or organizations around the world to formulate and improve the monitoring policies of antibiotic resistance, strengthen the supervision, strengthen the international cooperation and exchange, and curb the emergence and spread of drug-resistant strains.

scholarly journals Incidence, Distribution, and Spread of Tetracycline Resistance Determinants and Integron-Associated Antibiotic Resistance Genes among Motile Aeromonads from a Fish Farming Environment

2001 ◽  
Vol 67 (12) ◽  
pp. 5675-5682 ◽  
Author(s):  
Anja S. Schmidt ◽  
Morten S. Bruun ◽  
Inger Dalsgaard ◽  
Jens L. Larsen
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT A collection of 313 motile aeromonads isolated at Danish rainbow trout farms was analyzed to identify some of the genes involved in high levels of antimicrobial resistance found in a previous field trial (A. S. Schmidt, M. S. Bruun, I. Dalsgaard, K. Pedersen, and J. L. Larsen, Appl. Environ. Microbiol. 66:4908–4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among the isolates containing integrons, four different combinations of integrated resistance gene cassettes occurred, in all cases including a dihydrofolate reductase gene and a downstream aminoglycoside resistance insert (87 isolates) and occasionally an additional chloramphenicol resistance gene cassette (31 isolates). In addition, 23 isolates had “empty” integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class 1 integron. Out of 17 successful R-plasmid transfers to Escherichia coli recipients, the respective integrons were cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetApositive (10 of 17) and contained class 1 integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R-plasmids andtetA among the OTC-resistant aeromonads, tetEand the unclassified OTC resistance genes as well as class 1 integrons were equally distributed among isolates with and without plasmids. These findings indicate the implication of other mechanisms of gene transfer besides plasmid transfer in the dissemination of antibiotic resistance among environmental motile aeromonads.

scholarly journals Complete Nucleotide Sequence of Two Multidrug-Resistant IncR Plasmids from Klebsiella pneumoniae

2014 ◽  
Vol 58 (7) ◽  
pp. 4207-4210 ◽  
Author(s):  
Fabrice Compain ◽  
Lionel Frangeul ◽  
Laurence Drieux ◽  
Charlotte Verdet ◽  
Sylvain Brisse ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Nucleotide Sequence ◽  
Resistance Genes ◽  
Complete Nucleotide Sequence ◽  
Clinical Importance ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistance Determinants ◽  
Gene Carriers

ABSTRACTWe report here the complete nucleotide sequence of two IncR replicons encoding multidrug resistance determinants, including β-lactam (blaDHA-1,blaSHV-12), aminoglycoside (aphA1,strA,strB), and fluoroquinolone (qnrB4,aac6′-1b-cr) resistance genes. The plasmids have backbones that are similar to each other, including the replication and stability systems, and contain a wide variety of transposable elements carrying known antibiotic resistance genes. This study confirms the increasing clinical importance of IncR replicons as resistance gene carriers.

scholarly journals Conjugative delivery of CRISPR-Cas9 for the selective depletion of antibiotic-resistant enterococci

2019 ◽  
Author(s):  
Marinelle Rodrigues ◽  
Sara W. McBride ◽  
Karthik Hullahalli ◽  
Kelli L. Palmer ◽  
Breck A. Duerkop
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Resistance Genes ◽  
Bacterial Infections ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Conjugative Plasmid ◽  
Antibiotic Resistant ◽  
Resistance Determinants

AbstractThe innovation of new therapies to combat multidrug-resistant (MDR) bacteria is being outpaced by the continued rise of MDR bacterial infections. Of particular concern are hospital-acquired infections (HAIs) recalcitrant to antibiotic therapies. The Gram-positive intestinal pathobiontEnterococcus faecalisis associated with HAIs and some strains are MDR. Therefore, novel strategies to controlE. faecalispopulations are needed. We previously characterized anE. faecalisType II CRISPR-Cas system and demonstrated its utility in the sequence-specific removal of antibiotic resistance determinants. Here we present work describing the adaption of this CRISPR-Cas system into a constitutively expressed module encoded on a pheromone-responsive conjugative plasmid that efficiently transfers toE. faecalisfor the selective removal of antibiotic resistance genes. Usingin vitrocompetition assays, we show that these CRISPR-Cas-encoding delivery plasmids, or CRISPR-Cas antimicrobials, can reduce the occurrence of antibiotic resistance in enterococcal populations in a sequence-specific manner. Furthermore, we demonstrate that deployment of CRISPR-Cas antimicrobials in the murine intestine reduces the occurrence of antibiotic-resistantE. faecalisby several orders of magnitude. Finally, we show thatE. faecalisdonor strains harboring CRISPR-Cas antimicrobials are immune to uptake of antibiotic resistance determinantsin vivo. Our results demonstrate that conjugative delivery of CRISPR-Cas antimicrobials may be adaptable for future deployment from probiotic bacteria for exact targeting of defined MDR bacteria or for precision engineering of polymicrobial communities in the mammalian intestine.ImportanceCRISPR-Cas nucleic acid targeting systems hold promise for the amelioration of multidrug-resistant enterococci, yet the utility of such tools in the context of the intestinal environment where enterococci reside is understudied. We describe the development of a CRISPR-Cas antimicrobial, deployed on a conjugative plasmid, for the targeted removal of antibiotic resistance genes from intestinalEnterococcus faecalis. We demonstrate that CRISPR-Cas targeting reduces antibiotic resistance ofE. faecalisby several orders of magnitude in the intestine. Although barriers exist that influence the penetrance of the conjugative CRISPR-Cas antimicrobial among target recipientE. faecaliscells, the removal of antibiotic resistance genes inE. faecalisupon uptake of the CRISPR-Cas antimicrobial is absolute. In addition, cells that obtain the CRISPR-Cas antimicrobial are immunized against the acquisition of new antibiotic resistance genes. This study suggests a potential path toward plasmid based CRISPR-Cas therapies in the intestine.

scholarly journals Identification of Selected Antibiotic Resistance Genes in Two Different Wastewater Treatment Plant Systems in Poland: A Preliminary Study

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2851 ◽  
Author(s):  
Magdalena Pazda ◽  
Magda Rybicka ◽  
Stefan Stolte ◽  
Krzysztof Piotr Bielawski ◽  
Piotr Stepnowski ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Clear Trend ◽  
Resistance Determinants ◽  
Final Effluent

Antibiotic resistance is a growing problem worldwide. The emergence and rapid spread of antibiotic resistance determinants have led to an increasing concern about the potential environmental and public health endangering. Wastewater treatment plants (WWTPs) play an important role in this phenomenon since antibacterial drugs introduced into wastewater can exert a selection pressure on antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). Therefore, WWTPs are perceived as the main sources of antibiotics, ARB and ARG spread in various environmental components. Furthermore, technological processes used in WWTPs and its exploitation conditions may influence the effectiveness of antibiotic resistance determinants’ elimination. The main aim of the present study was to compare the occurrence of selected tetracycline and sulfonamide resistance genes in raw influent and final effluent samples from two WWTPs different in terms of size and applied biological wastewater treatment processes (conventional activated sludge (AS)-based and combining a conventional AS-based method with constructed wetlands (CWs)). All 13 selected ARGs were detected in raw influent and final effluent samples from both WWTPs. Significant ARG enrichment, especially for tet(B, K, L, O) and sulIII genes, was observed in conventional WWTP. The obtained data did not show a clear trend in seasonal fluctuations in the abundance of selected resistance genes in wastewaters.

scholarly journals Implications of indoor microbial ecology and evolution on antibiotic resistance

2019 ◽  
Vol 30 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Sarah Ben Maamar ◽  
Jinglin Hu ◽  
Erica M. Hartmann
Keyword(s):  
Antibiotic Resistance ◽  
Built Environment ◽  
Health Outcomes ◽  
Resistance Genes ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Building Design ◽  
Microbial Interactions ◽  
Environment Design ◽  
Positive Health

Abstract The indoor environment is an important source of microbial exposures for its human occupants. While we naturally want to favor positive health outcomes, built environment design and operation may counter-intuitively favor negative health outcomes, particularly with regard to antibiotic resistance. Indoor environments contain microbes from both human and non-human origins, providing a unique venue for microbial interactions, including horizontal gene transfer. Furthermore, stressors present in the built environment could favor the exchange of genetic material in general and the retention of antibiotic resistance genes in particular. Intrinsic and acquired antibiotic resistance both pose a potential threat to human health; these phenomena need to be considered and controlled separately. The presence of both environmental and human-associated microbes, along with their associated antibiotic resistance genes, in the face of stressors, including antimicrobial chemicals, creates a unique opportunity for the undesirable spread of antibiotic resistance. In this review, we summarize studies and findings related to various interactions between human-associated bacteria, environmental bacteria, and built environment conditions, and particularly their relation to antibiotic resistance, aiming to guide “healthy” building design.

scholarly journals Screening and Quantification of the Expression of Antibiotic Resistance Genes in Acinetobacter baumannii with a Microarray

2009 ◽  
Vol 54 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Sébastien Coyne ◽  
Ghislaine Guigon ◽  
Patrice Courvalin ◽  
Bruno Périchon
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Antibiotic Resistance Genes ◽  
Efflux Pumps ◽  
Single Step ◽  
Resistance Determinants

ABSTRACT An oligonucleotide-based DNA microarray was developed to evaluate expression of genes for efflux pumps in Acinetobacter baumannii and to detect acquired antibiotic resistance determinants. The microarray contained probes for 205 genes, including those for 47 efflux systems, 55 resistance determinants, and 35 housekeeping genes. The microarray was validated by comparative analysis of mutants overexpressing or deficient in the pumps relative to the parental strain. The performance of the microarray was also evaluated using in vitro single-step mutants obtained on various antibiotics. Overexpression, confirmed by quantitative reverse transcriptase PCR, of RND efflux pumps AdeABC, due to a G30D substitution in AdeS in a multidrug-resistant (MDR) strain obtained on gentamicin, and AdeIJK, in two mutants obtained on cefotaxime or tetracycline, was detected. A new efflux pump, AdeFGH, was found to be overexpressed in a mutant obtained on chloramphenicol. Study of MDR clinical isolates, including the AYE strain, whose entire sequence has been determined, indicated overexpression of AdeABC and of the chromosomally encoded cephalosporinase as well as the presence of several acquired resistance genes. The overexpressed and acquired determinants detected by the microarray could account for nearly the entire MDR phenotype of the isolates. The microarray is potentially useful for detection of resistance in A. baumannii and should allow detection of new efflux systems associated with antibiotic resistance.

Sign in / Sign up

Export Citation Format

Share Document