# What's going on in hospital effluent biofilm?

Geneviève Bricheux, Cécile Hilpert, Florence Donnadieu-Bernard, C. Hennequin, Christiane Forestier, Ousmane Traoré, Didier Debroas, Florence Donnadieu-Bernard

► To cite this version:

Geneviève Bricheux, Cécile Hilpert, Florence Donnadieu-Bernard, C. Hennequin, Christiane Forestier, et al.. What's going on in hospital effluent biofilm?. 8th congress of European Microbiology, Jul 2019, Glasgow, United Kingdom. hal-04939816

HAL Id: hal-04939816

https://hal.science/hal-04939816v1

Submitted on 11 Feb 2025

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<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# What's going on in hospital effluent biofilm?

Bricheux G¹; Hilpert C¹; Bernard F¹; Hennequin C¹⁻²; Forestier C¹; Traore O¹⁻²; Debroas D¹.

¹-LMGE, UMR CNRS 6023 University Clermont Auvergne, Clermont-Ferrand F-63000, ²-CHU Gabriel Montpied, Clermont-Ferrand, F-63000

**KNOW YOUR ENEMY** : Antibiotic resistance is a growing global public threat with serious health, political, and economic implications. Hospitals are a source of antibiotic molecules and resistance genes as their effluents are discharged into the sewer systems, rivers, lakes, and seas without prior treatment. However, bacteria in hospital effluent biofilms are exposed to stressful conditions leading to the survey of a limited number of species, i.e. the survivors, which could play a role of reservoir, "the place to be" to exchange resistance genes.

## In situ biofilm formation, microbial content analysis

<figure><img src="image_2.png" /><figcaption>Biofilms formed on glass slides in hospital effluent</figcaption></figure>

Three-week old biofilms are composed of bacteria embedded in a rather thin matrix.

SYBR®Green and propidium iodide (PI) staining:

2 populations:
- Living cells 49% (white circle)
- Damaged Cells 41% (Red circle)

**Resfams Ab classification**

| | % |
| :--- | :--- |
| **Others Efflux** | 56.0 |
| **ABC Transporter** | 12.3 |
| **RND Antibiotic Efflux** | 9.5 |
| **Glycopeptide Resistance** | 8.3 |
| **Beta-Lactamase** | 6.38 |
| **Aminoglycoside Modifying Enz** | 2.88 |
| **Gene Modulating Resistance** | 2.11 |
| **Quinolone Resistance** | 1.00 |
| **MFS Transporter** | 0.52 |
| **Chloramphenicol Resistance** | 0.36 |
| **rRNA Methyltransferase** | 0.24 |
| **Tetracycline MFS Efflux** | 0.17 |
| **Tet Ribosomal Protection** | |
| **Tet Inactivation** | |

## Antibiotic resistance genes

EmrE, AdeS, AdeR

ABC efflux, macA-B, msbA, tolC

RND, AdeA-I-B, MexA-C-E-H, adeC-K-oprM

VanR-S-H-D

Class A-B, subclass B1-B3

AAC3,ANT, APH3

baeR-S, bla, marA, mecR1, RamA, robA, RomA, SoxR

Qnr

emrB, MFS

**Efflux pump encoding genes** are the most frequently detected. They encode proteins involved in the secretion of toxic substances and antibiotics; a process considered to be a vital part of xenobiotic metabolism.

<figure><img src="image_3.png" /><figcaption>Extraction using a manual alkaline mini-prep</figcaption></figure>

Illumina sequencing of plasmid extract:

Reads number : 107 734 274

Sequences treatment with PlasPredict

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

**Contigs plasmids:**

Number : 8,267

Total length: 20,546,830 bp

Med size: 2,485 bp

381 circular plasmids (1,4 Kb to 236Kb)

9490 linear contigs (74bp to 236Kb)

Two contigs already in database:

E. coli plasmid pE35BA_1, complete sequence (5Kb)

E. coli plasmid pEco70745_4, complete sequence (2Kb)

## Mobile repertoire

<table><thead><tr><th>Contigs</th><th>Number</th></tr></thead><tbody><tr><td>MOB</td><td>162 (103 MOB<sub>P</sub>, 30 MOB<sub>Q</sub>, 12 MOB<sub>F</sub>, 6 MOB<sub>H</sub>, 5 MOB<sub>V</sub>, 2 MOB<sub>C</sub>)</td></tr><tr><td>MPF</td><td>333 (106 MPF<sub>F</sub>, 40 MPF<sub>G</sub>, 7 MPF<sub>I</sub>, 176 MPF<sub>T</sub>)</td></tr><tr><td>OriT</td><td>296</td></tr></tbody></table>

The mobile repertoire is composed of conjugative and mobilizable plasmids, integrative and conjugative elements and integrative and mobilizable elements.

## Taxonomy

<table><thead><tr><th>Taxon</th><th>Number of contigs</th><th>%</th></tr></thead><tbody><tr><td>Actinobacteria</td><td>3</td><td>0,092</td></tr><tr><td>Bacteroidetes</td><td>4</td><td>0,12</td></tr><tr><td>Firmicutes</td><td>4</td><td>0,12</td></tr><tr><td><span style="color:red;">Proteobacteria</span></td><td><span style="color:red;">2556</span></td><td><span style="color:red;">77,80</span></td></tr><tr><td>unclassified</td><td>718</td><td>21,85</td></tr><tr><td></td><td>3285</td><td></td></tr></tbody></table>

The diversity of species is very low with mainly gammaproteobacteria