Antibiotic Resistance Mechanisms and Their Transmission in Acinetobacter baumannii

McCarthy, Ronan R.; Larrouy-Maumus, Gérald; Tan, Mei Gei C. Meiqi; Wareham, David W.

doi:10.1007/978-3-030-67452-6_7

Cited by 9 publications

(11 citation statements)

References 169 publications

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“… 1–3 However, it can also be an opportunistic pathogen that infects immunocompromised patients. 3 , 4 Nowadays, it is estimated that up to 10% of nosocomial infections in the USA and 2% in Europe are caused by this pathogen, with these frequencies almost doubling in Asia and the Middle East. Furthermore, around 45% of A. baumannii isolates in global terms exhibit MDR (i.e.…”

Section: Introductionmentioning

confidence: 99%

A high-efficiency scar-free genome-editing toolkit for Acinetobacter baumannii

Dios

Gadar

McCarthy

2022

Journal of Antimicrobial Chemotherapy

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Background The current mutagenesis tools for Acinetobacter baumannii leave selection markers or residual sequences behind, or involve tedious counterselection and screening steps. Furthermore, they are usually adapted for model strains, rather than for MDR clinical isolates. Objectives To develop a scar-free genome-editing tool suitable for chromosomal and plasmid modifications in MDR A. baumannii AB5075. Methods We prove the efficiency of our adapted genome-editing system by deleting the multidrug efflux pumps craA, cmlA5 and resistance island 2 (RI2), as well as curing plasmid p1AB5075, and combining these mutations. We then characterized the susceptibility of the mutants compared with the WT to different antibiotics (i.e. chloramphenicol, amikacin and tobramycin) by disc diffusion assays and determined the MIC for each strain. Results We successfully adapted the genome-editing protocol to A. baumannii AB5075, achieving a double recombination frequency close to 100% and routinely securing the construction of a mutant within 10 working days. Furthermore, we show that both CraA and p1AB5075 are involved in chloramphenicol resistance, and that RI2 and p1AB5075 play a role in resistance to amikacin and tobramycin. Conclusions We have developed a versatile and highly efficient genome-editing tool for A. baumannii. We have demonstrated it can be used to modify both the chromosome and native plasmids. By challenging the method, we show the role of CraA and p1AB5075 in antibiotic resistance.

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Section: Introductionmentioning

confidence: 99%

A high-efficiency scar-free genome-editing toolkit for Acinetobacter baumannii

Dios

Gadar

McCarthy

2022

Journal of Antimicrobial Chemotherapy

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“…2 Oftentimes, these features can spread among the population through mobile genetic elements and the ability of A. baumannii to be naturally competent. 2,8-10…”

Section: Introductionmentioning

confidence: 99%

“…However, it can also be an opportunistic pathogen that infects immunocompromised patients. 1,2 Nowadays, it is estimated that up to 10% of nosocomial infections in the United States and 2% in Europe are caused by this pathogen, with these frequencies almost doubling in Asia and the Middle East. Furthermore, around 45% of A. baumannii isolates in global terms exhibit multi-drug resistance (MDR, i.e.…”

Section: Introductionmentioning

confidence: 99%

“…ribosomal proteins, penicillin binding proteins, DNA replication enzymes and the lipid A biosynthetic pathway), as well as enzymes that degrade/inactivate antibiotics. 2 Oftentimes, these features can spread among the population through mobile genetic elements and the ability of A. baumannii to be naturally competent. 2,[8][9][10] With technological advances, genome editing tools have evolved, allowing precise genome editing (i.e.…”

Section: Introductionmentioning

confidence: 99%

“…2 Oftentimes, these features can spread among the population through mobile genetic elements and the ability of A. baumannii to be naturally competent. 2,[8][9][10] With technological advances, genome editing tools have evolved, allowing precise genome editing (i.e. insertions and deletions), from a single nucleotide to dozens of kilobases.…”

Section: Introductionmentioning

confidence: 99%

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A high-efficiency scar-free genome editing toolkit for Acinetobacter baumannii

Dios

Gadar

McCarthy

2022

Preprint

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Structured synopsisBackgroundThe current mutagenesis tools for Acinetobacter baumannii leave selection markers or residual sequences behind, or involve tedious counterselection and screening steps. Furthermore, they are usually adapted for model strains, rather than to multidrug resistant (MDR) clinical isolates.ObjectivesTo develop a scar-free genome editing tool suitable for chromosomal and plasmid modifications in MDR A. baumannii AB5075.MethodsWe prove the efficiency of our adapted genome editing system by deleting the multidrug efflux pumps craA and cmlA5, as well as curing plasmid p1AB5075. We then characterised the antibiotic sensitivity phenotype of the mutants compared to the wild type for chloramphenicol, tobramycin and amikacin by disc diffusion assays and determined their minimum inhibitory concentration for each strain.ResultsWe successfully adapted the genome editing protocol to A. baumannii AB5075, achieving a double recombination frequency close to 100% and securing the construction of a mutant within 10 work days. Furthermore, we show that the ΔcraA has a strong sensitivity to chloramphenicol, tobramycin and amikacin, whereas the ΔcmlA5 mutant does not show a significant decrease in viability for the antibiotics tested. On the other hand, the removal of p1AB5075 produced an increased sensitivity to tobramycin and amikacin.ConclusionWe have adapted a highly efficient genome editing tool for A. baumannii and proved that craA has a broader substrate range than previously thought. On the other hand, whereas cmlA5 is annotated as a chloramphenicol efflux pump and is encoded within an aminoglycoside resistance island, it does not provide resistance to any of those compounds.

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