Hidden Selection of Bacterial Resistance to Fluoroquinolones In Vivo: The Case of Legionella pneumophila and Humans.
BACKGROUND
Infectious diseases are the leading cause of human morbidity and mortality worldwide. One dramatic issue is the emergence of microbial resistance to antibiotics which is a major public health concern. Surprisingly however, such in vivo adaptive ability has not been reported yet for many intracellular human bacterial pathogens such as Legionella pneumophila.


METHODS
We examined 82 unrelated patients with Legionnaire's disease from which 139 respiratory specimens were sampled during hospitalization and antibiotic therapy. We both developed a real time PCR assay and used deep-sequencing approaches to detect antibiotic resistance mutations in L. pneumophila and follow their selection and fate in these samples.


RESULTS
We identified the in vivo selection of fluoroquinolone resistance mutations in L. pneumophila in two infected patients treated with these antibiotics. By investigating the mutational dynamics in patients, we showed that antibiotic resistance occurred during hospitalization most likely after fluoroquinolone treatment.


CONCLUSIONS
In vivo selection of antibiotic resistances in L. pneumophila may be associated with treatment failures and poor prognosis. This hidden resistance must be carefully considered in the therapeutic management of legionellosis patients and in the control of the gradual loss of effectiveness of antibiotics.
Univ. Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), F-38000 Grenoble, France ; Centre National de la Recherche Scientifique (CNRS), LAPM, F-38000 Grenoble, France ; Centre Hospitalier Universitaire (CHU) Grenoble, Institut de Biologie et de Pathologie, Grenoble, France.
Lubana
L
Shadoud
Univ. Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), F-38000 Grenoble, France ; Centre National de la Recherche Scientifique (CNRS), LAPM, F-38000 Grenoble, France ; Centre Hospitalier Universitaire (CHU) Grenoble, Institut de Biologie et de Pathologie, Grenoble, France.
Iyad
I
Almahmoud
Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France ; CNRS UMR5308, Ecoles Normales Supérieures (ENS), Lyon, France ; Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, Lyon, France ; Centre National de Référence des Legionella , Centre de Biologie Est, Hospices Civils de Lyon, Lyon, France.
Sophie
S
Jarraud
Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France ; CNRS UMR5308, Ecoles Normales Supérieures (ENS), Lyon, France ; Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, Lyon, France ; Centre National de Référence des Legionella , Centre de Biologie Est, Hospices Civils de Lyon, Lyon, France.
Jérôme
J
Etienne
Unit of Virus host Cell Interactions (UVHCI), UMI 3265, Univ. Grenoble Alpes, European Molecular Biology Laboratory (EMBL), Centre National de la Recherche Scientifique (CNRS), Grenoble, France.
Sylvie
S
Larrat
CHU Grenoble, Réanimation Médicale, Grenoble, France.
Carole
C
Schwebel
CHU Grenoble, Réanimation Médicale, Grenoble, France ; INSERM U823, Institut Albert Bonniot, Grenoble, France.
Jean-François
JF
Timsit
Univ. Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), F-38000 Grenoble, France ; Centre National de la Recherche Scientifique (CNRS), LAPM, F-38000 Grenoble, France.
Dominique
D
Schneider
Univ. Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes (LAPM), F-38000 Grenoble, France ; Centre National de la Recherche Scientifique (CNRS), LAPM, F-38000 Grenoble, France ; Centre Hospitalier Universitaire (CHU) Grenoble, Institut de Biologie et de Pathologie, Grenoble, France.
Max
M
Maurin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load / Q000235:genetics; D015331:Cohort Studies; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology*; D005798:Genes, Bacterial; D006801:Humans; D016952:Legionella pneumophila / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics
D004269:DNA, Bacterial; D024841:Fluoroquinolones
Fluoroquinolone resistance; In vivo selection; Legionella pneumophila; Legionellosis; Next generation sequencing; Resistance detection