# Characterization of tigecycline (tet(X)) and multidrug-resistant Acinetobacter lwoffii/pseudolwoffii from French animals

Leila Hamze, Antoine Drapeau, Pierre Châtre, Estelle Saras, Jean-Yves

Madec, Marisa Haenni, Agnese Lupo

► To cite this version:

Leila Hamze, Antoine Drapeau, Pierre Châtre, Estelle Saras, Jean-Yves Madec, et al.. Characterization of tigecycline (tet(X)) and multidrug-resistant Acinetobacter lwoffii/pseudolwoffii from French animals. 13th International Symposium on the Biology of Acinetobacter, Jun 2023, Coimbra, Portugal. anses-04276211

HAL Id: anses-04276211

https://anses.hal.science/anses-04276211

Submitted on 8 Nov 2023

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# Characterization of tigecycline (*tet(X*) and multidrug-resistant *Acinetobacter lwoffii/pseudolwoffii* from French animals

Leila Hamze, Antoine Drapeau, Pierre Chatre, Estelle Saras, Jean-Yves Madec, Marisa Haenni, Agnese Lupo

University of Lyon 1 – Anses, Laboratory of Lyon, 31 Avenue Tony Garnier, 69007 Lyon, France

Contact: [agnese.lupo@anses.fr](mailto:agnese.lupo@anses.fr)

## Background

Tigecycline is a last-resort antibiotic restricted to humans for treating severe infections caused by multidrug-resistant bacteria.

Plasmid-located tigecycline-resistance genes tet(X) have been characterized since 2019 in Enterobacterales and Acinetobacter species.

In the current study, the genetic content of animal Acinetobacter lwoffii/pseudolwoffii exhibiting tigecycline non-susceptibility was characterized.

## Results

rMLST confirmed A. lwoffii identification for two isolates, whereas two were assigned to A. pseudolwoffii. All of them belonged to novel sequence types and carried numerous antibiotic resistance genes (Table 1).

The four tigecycline-non susceptible strains carried gene tet(X3). Full assemby in strains 43620 and 49430 revealed that tet(X3) was located on a IS91 mediated transposon (Figure 1).

In turn, these elements were located on plasmids with predicted structures for self-transfer (Figure 2).

<figure><img src="image_3.png" /><figcaption>**Figure 1.** A. Graphical representation of the genetic environment surrounding tet(X) gene in 43620 and 49430 (A), *bla*<sub>VEB-1</sub> gene in 43620 (B), and *bla*<sub>OXA-58</sub> in 49430 (C) (Easyfig v.2.5.).</figcaption></figure>

## Material and methods

During 2016-2022, four tigecycline non-susceptible A. lwoffii isolates (E-test 2 mg/L) were collected through the diagnostic laboratories of the Resapath (https://resapath.anses.fr).

Genomes were sequenced by short (Illumina) and, for two isolates, by long reads (Oxford Nanopore) approaches. Assembly was performed using Shovill v1.0.4 and Unicycler v0.4.8. Antibiotic resistance genes and sequence type were analyzed on the BV-BRC platform based on the CARD database and the Institut Pasteur scheme, respectively.

<table><caption>Table 1. Features of Acinetobacter lwoffii/pseudolwoffii strains from French diseased animals.</caption><thead><tr><th>Isolate</th><th>Identification</th><th>Year of isolation</th><th>Host</th><th>Source</th><th>ST*</th><th>Antibiotic resistance genes</th></tr></thead><tbody><tr><td>43620</td><td>A. pseudolwoffii</td><td>2016</td><td>Horse</td><td>Endometre</td><td>1792</td><td>bla<sub>VEB-1</sub>, bla<sub>TEM-2</sub>, aadA1, strA, strB, sul1, sul2, tet(A), tet(X3), mph(E), msr(E), floR, arr-3</td></tr><tr><td>48934</td><td>A. lwoffii</td><td>2017</td><td>Cat</td><td>Nose</td><td>1960</td><td>bla<sub>CARB-5</sub>, bla<sub>TEM-2</sub>, strA, strB, aph(3')-la, aac(3)-IIa, sul2, tet(X3), floR, InuG</td></tr><tr><td>49430</td><td>A. pseudolwoffii</td><td>2018</td><td>Horse</td><td>Peritoneum</td><td>1968</td><td>bla<sub>CARB-5</sub>, bla<sub>OXA-58</sub>, strA, strB, aph(3')-la, aac(3)-IIa, sul2, dfrA36, tet(X3), cat(A1), mph(E), msr(E)</td></tr><tr><td>61450</td><td>A. lwoffii</td><td>2022</td><td>Horse</td><td>Endometre</td><td>2258</td><td>bla<sub>VEB-1</sub>, strA, strB, aac(3)-IIa, aac(6)-lb-cr, sul1, sul2, tet(A), tet(X3), mph(E), msr(E), floR, arr-3</td></tr></tbody></table>

*: most similar sequence type from the Institut Pasteur scheme

<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /><figcaption>**Figure 2.** Circular representation of multidrug resistance plasmids.</figcaption></figure>

In red antibiotic resistance genes, in green and purple CDS on positive and negative strand respectively.

Resistance genes (clockwise) in:

- p49430_1: tet(X3), dfrA36, sul1, strB, strA, aac(3")-IIa, cat(A1)

- p49430_2: msr(E), mph(E), bla<sub>CARB-16</sub>, bla<sub>OXA-58</sub>

- p43620

region 1: tet(X3), floR, mph(E), sul1, strB, strA, bla<sub>TEM-1</sub>, aph(3")-I

region 2: strB, strA, msr(E), mph(E), aph(3")-I, ant(3")-la, sul1, tetA, bla<sub>VEB-1</sub>, sul1

<figure><img src="image_6.png" /></figure>

## Conclusion

Genes tet(X) and tigecycline resistance in Acinetobacter spp. were so far unreported among French animals. In general, tet(X) occurrence in Europe is rare, with two reports in tissues of dead animals from Italy and one from environmental source from Norway.

However, their localization on predicted mobile elements could rapidly change the epidemiological picture.

Surveillance of this major resistance mechanism is important for animal and human health.

Furthermore, these results underline the necessity of rationale usage of "old" antibiotics such as tetracycline, which regained interest to avoid the use of last-generations antibiotics but could co-select multiple and major resistance mechanisms in animals.