scholarly journals Scarless removal of large resistance island AbaR results in antibiotic susceptibility and increased natural transformability in Acinetobacter baumannii

2020 ◽  
Author(s):  
Anne-Sophie Godeux ◽  
Elin Svedholm ◽  
Agnese Lupo ◽  
Marisa Haenni ◽  
Maria-Halima Laaberki ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Insertion Site ◽  
Antibiotic Resistance Genes ◽  
Multi Drug Resistance ◽  
Bacterial Physiology ◽  
Functional Consequences ◽  
Resistance Island ◽  
Insight Into ◽  
Effective Contribution

ABSTRACTWith a great diversity in gene composition including multiple putative antibiotic-resistance genes, AbaR islands are potential contributors to multi-drug resistance in Acinetobacter baumannii. However, the effective contribution of AbaR to antibiotic resistance and bacterial physiology remains elusive. To address this, we sought to accurately remove AbaR islands and restore the integrity of their insertion site. To this end, we devised a versatile scarless genome editing strategy. We performed this genetic modification in two recent A. baumannii clinical strains: the strain AB5075 and the nosocomial strain AYE which carry AbaR11 and AbaR1 islands of 19.7 kbp and 86.2 kbp, respectively. Antibiotic susceptibilities were then compared between the parental strains and their AbaR-cured derivatives. As anticipated by the predicted function of the ORF of this island, the antibiotic resistance profiles were identical between the wild type and the AbaR11-cured AB5075 strains. In contrast, AbaR1 carries 25 ORFs with a predicted resistance to several classes of antibiotics and the AYE AbaR1-cured derivative showed restored susceptibility to multiple classes of antibiotics. Moreover, curing of AbaRs restored high levels of natural transformability. Indeed, most AbaR islands are inserted into the comM gene involved in natural transformation. Our data indicate that AbaR insertion effectively inactivates comM and that the restored comM is functional. Curing of AbaR consistently resulted in highly transformable, and therefore, easily genetically tractable strains. Emendation of AbaR provides insight into the functional consequences of AbaR acquisition.

scholarly journals Scarless Removal of Large Resistance Island AbaR Results in Antibiotic Susceptibility and Increased Natural Transformability in Acinetobacter baumannii

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Anne-Sophie Godeux ◽  
Elin Svedholm ◽  
Agnese Lupo ◽  
Marisa Haenni ◽  
Samuel Venner ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Insertion Site ◽  
Antibiotic Resistance Genes ◽  
Content Type ◽  
Reading Frame ◽  
Bacterial Physiology ◽  
Functional Consequences ◽  
Resistance Island ◽  
Effective Contribution

ABSTRACT With a great diversity in gene composition, including multiple putative antibiotic resistance genes, AbaR islands are potential contributors to multidrug resistance in Acinetobacter baumannii. However, the effective contribution of AbaR to antibiotic resistance and bacterial physiology remains elusive. To address this, we sought to accurately remove AbaR islands and restore the integrity of their insertion site. To this end, we devised a versatile scarless genome editing strategy. We performed this genetic modification in two recent A. baumannii clinical strains: the strain AB5075 and the nosocomial strain AYE, which carry AbaR11 and AbaR1 islands of 19.7 kbp and 86.2 kbp, respectively. Antibiotic susceptibilities were then compared between the parental strains and their AbaR-cured derivatives. As anticipated by the predicted function of the open reading frame (ORF) of this island, the antibiotic resistance profiles were identical between the wild type and the AbaR11-cured AB5075 strains. In contrast, AbaR1 carries 25 ORFs, with predicted resistance to several classes of antibiotics, and the AYE AbaR1-cured derivative showed restored susceptibility to multiple classes of antibiotics. Moreover, curing of AbaRs restored high levels of natural transformability. Indeed, most AbaR islands are inserted into the comM gene involved in natural transformation. Our data indicate that AbaR insertion effectively inactivates comM and that the restored comM is functional. Curing of AbaR consistently resulted in highly transformable and therefore easily genetically tractable strains. Emendation of AbaR provides insight into the functional consequences of AbaR acquisition.

Acquisition of a genomic resistance island (AbGRI5) from global clone 2 through homologous recombination in a clinical Acinetobacter baumannii isolate

2020 ◽  
Vol 76 (1) ◽  
pp. 65-69
Author(s):  
Xiaoting Hua ◽  
Robert A Moran ◽  
Qingye Xu ◽  
Jintao He ◽  
Youhong Fang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Whole Genome Sequence ◽  
Oxford Nanopore ◽  
History Of ◽  
Agar Dilution ◽  
Resistance Island ◽  
New Location

Abstract Objectives To reconstruct the evolutionary history of the clinical Acinetobacter baumannii XH1056, which lacks the Oxford scheme allele gdhB. Methods Susceptibility testing was performed using broth microdilution and agar dilution. The whole-genome sequence of XH1056 was determined using the Illumina and Oxford Nanopore platforms. MLST was performed using the Pasteur scheme and the Oxford scheme. Antibiotic resistance genes were identified using ABRicate. Results XH1056 was resistant to all antibiotics tested, apart from colistin, tigecycline and eravacycline. MLST using the Pasteur scheme assigned XH1056 to ST256. However, XH1056 could not be typed with the Oxford MLST scheme as gdhB is not present. Comparative analyses revealed that XH1056 contains a 52 933 bp region acquired from a global clone 2 (GC2) isolate, but is otherwise closely related to the ST23 A. baumannii XH858. The acquired region in XH1056 also contains a 34 932 bp resistance island that resembles AbGRI3 and contains the armA, msrE-mphE, sul1, blaPER-1, aadA1, cmlA1, aadA2, blaCARB-2 and ere(B) resistance genes. Comparison of the XH1056 chromosome to that of GC2 isolate XH859 revealed that the island in XH1056 is in the same chromosomal region as that in XH859. As this island is not in the standard AbGRI3 position, it was named AbGRI5. Conclusions XH1056 is a hybrid isolate generated by the acquisition of a chromosomal segment from a GC2 isolate that contains a resistance island in a new location—AbGRI5. As well as generating ST256, it appears likely that a single recombination event is also responsible for the acquisition of AbGRI5 and its associated antibiotic resistance genes.

scholarly journals Genomic Analysis of the Multidrug-Resistant Acinetobacter baumannii Strain MDR-ZJ06 Widely Spread in China

2011 ◽  
Vol 55 (10) ◽  
pp. 4506-4512 ◽  
Author(s):  
Hua Zhou ◽  
Tongwu Zhang ◽  
Dongliang Yu ◽  
Borui Pi ◽  
Qing Yang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Content Type ◽  
Resistance Island

ABSTRACTWe previously reported that the multidrug-resistant (MDR)Acinetobacter baumanniistrain MDR-ZJ06, belonging to European clone II, was widely spread in China. In this study, we report the whole-genome sequence of this clinically important strain. A 38.6-kb AbaR-type genomic resistance island (AbaR22) was identified in MDR-ZJ06. AbaR22 has a structure similar to those of the resistance islands found inA. baumanniistrains AYE and AB0057, but it contained only a few antibiotic resistance genes. The region of resistant gene accumulation as previously described was not found in AbaR22. In the chromosome of the strain MDR-ZJ06, we identified the geneblaoxa-23in a composite transposon (Tn2009). Tn2009shared the backbone with otherA. baumanniitransponsons that harborblaoxa-23, but it was bracketed by two ISAba1elements which were transcribed in the same orientation. MDR-ZJ06 also expressed thearmAgene on its plasmid pZJ06, and this gene has the same genetic environment as thearmAgene of theEnterobacteriaceae. These results suggest variability of resistance acquisition even in closely relatedA. baumanniistrains.

scholarly journals Emerging MDR-Pseudomonas aeruginosa in fish commonly harbor oprL and toxA virulence genes and blaTEM, blaCTX-M, and tetA antibiotic-resistance genes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdelazeem M. Algammal ◽  
Mahmoud Mabrok ◽  
Elayaraja Sivaramasamy ◽  
Fatma M. Youssef ◽  
Mona H. Atwa ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Antibiotic Resistance Genes ◽  
Health Concern ◽  
Diffusion Method ◽  
Multi Drug Resistance ◽  
Fish Farms ◽  
M Gene ◽  
Total Prevalence

Abstract This study aimed to investigate the prevalence, antibiogram of Pseudomonasaeruginosa (P.aeruginosa), and the distribution of virulence genes (oprL,exoS, phzM, and toxA) and the antibiotic-resistance genes (blaTEM, tetA, and blaCTX-M). A total of 285 fish (165 Oreochromisniloticus and 120 Clariasgariepinus) were collected randomly from private fish farms in Ismailia Governorate, Egypt. The collected specimens were examined bacteriologically. P. aeruginosa was isolated from 90 examined fish (31.57%), and the liver was the most prominent infected organ. The antibiogram of the isolated strains was determined using a disc diffusion method, where the tested strains exhibited multi-drug resistance (MDR) to amoxicillin, cefotaxime, tetracycline, and gentamicin. The PCR results revealed that all the examined strains harbored (oprL and toxA) virulence genes, while only 22.2% were positive for the phzM gene. On the contrary, none of the tested strains were positive for the exoS gene. Concerning the distribution of the antibiotic resistance genes, the examined strains harbored blaTEM, blaCTX-M, and tetA genes with a total prevalence of 83.3%, 77.7%, and 75.6%, respectively. Experimentally infected fish with P.aeruginosa displayed high mortalities in direct proportion to the encoded virulence genes and showed similar signs of septicemia found in the naturally infected one. In conclusion, P.aeruginosa is a major pathogen of O.niloticus and C.gariepinus.oprL and toxA genes are the most predominant virulence genes associated with P.aeruginosa infection. The blaCTX-M,blaTEM, and tetA genes are the main antibiotic-resistance genes that induce resistance patterns to cefotaxime, amoxicillin, and tetracycline, highlighting MDR P.aeruginosa strains of potential public health concern.

scholarly journals Genomic analysis reveals high virulence and antibiotic resistance amongst phage susceptible Acinetobacter baumannii

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Udomluk Leungtongkam ◽  
Rapee Thummeepak ◽  
Thawatchai Kitti ◽  
Kannipa Tasanapak ◽  
Jintana Wongwigkarn ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Copper Tolerance ◽  
Virulence Determinants ◽  
Genome Sequences ◽  
High Virulence

Abstract In this study, we examined the association between antimicrobial resistance, CRISPR/Cas systems and virulence with phage susceptibility in Acinetobacter baumannii and investigated draft genomes of phage susceptible multidrug resistant A. baumannii strains from Thailand. We investigated 230 A. baumannii strains using 17 lytic A. baumannii phages and the phage susceptibility was 46.5% (107/230). Phage susceptibility was also associated with resistance to numerous antibiotics (p-value < 0.05). We also found association between biofilm formation and the presence of ompA gene among phage susceptible A. baumannii strains (p-value < 0.05). A. baumannii isolates carrying cas5 or combinations of two or three other cas genes, showed a significant increase in phage resistance. Whole-genome sequences of seven phage susceptible A. baumannii isolates revealed that six groups of antibiotic resistance genes were carried by all seven phage susceptible A. baumannii. All strains carried biofilm associated genes and two strains harbored complete prophages, acquired copper tolerance genes, and CRISPR-associated (cas) genes. In conclusion, our data exhibits an association between virulence determinants and biofilm formation among phage susceptible A. baumannii strains. These data help to understand the bacterial co-evolution with phages.

scholarly journals Understanding the basis of antibiotic resistance: a platform for drug discovery

Microbiology ◽  
2014 ◽  
Vol 160 (11) ◽  
pp. 2366-2373 ◽  
Author(s):  
Laura J. V. Piddock
Keyword(s):  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multi Drug Resistance ◽  
Annual Conference ◽  
Altered Expression ◽  
Genetic Inactivation ◽  
Fluoroquinolone Antibiotics ◽  
Serovar Typhimurium

There are numerous genes in Salmonella enterica serovar Typhimurium that can confer resistance to fluoroquinolone antibiotics, including those that encode topoisomerase proteins, the primary targets of this class of drugs. However, resistance is often multifactorial in clinical isolates and it is not uncommon to also detect mutations in genes that affect the expression of proteins involved in permeability and multi-drug efflux. The latter mechanism, mediated by tripartite efflux systems, such as that formed by the AcrAB–TolC system, confers inherent resistance to many antibiotics, detergents and biocides. Genetic inactivation of efflux genes gives multi-drug hyper-susceptibility, and in the absence of an intact AcrAB–TolC system some chromosomal and transmissible antibiotic resistance genes no longer confer clinically relevant levels of resistance. Furthermore, a functional multi-drug resistance efflux pump, such as AcrAB–TolC, is required for virulence and the ability to form a biofilm. In part, this is due to altered expression of virulence and biofilm genes being sensitive to efflux status. Efflux pump expression can be increased, usually due to mutations in regulatory genes, and this confers resistance to clinically useful drugs such as fluoroquinolones and β-lactams. Here, I discuss some of the work my team has carried out characterizing the mechanisms of antibiotic resistance in Salmonella enterica serovar Typhimurium from the late 1980s to 2014. A video of this Prize Lecture, presented at the Society for General Microbiology Annual Conference 2014, can be viewed via this link: https://www.youtube.com/watch?v=MCRumMV99Yw.

scholarly journals Using WGS to identify antibiotic resistance genes and predict antimicrobial resistance phenotypes in MDR Acinetobacter baumannii in Tanzania

2019 ◽  
Vol 74 (6) ◽  
pp. 1484-1493 ◽  
Author(s):  
Happiness H Kumburu ◽  
Tolbert Sonda ◽  
Marco van Zwetselaar ◽  
Pimlapas Leekitcharoenphon ◽  
Oksana Lukjancenko ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes
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