Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species
Résumé
Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in
the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial
infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved
in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in
particular in the intensive care unit; this persistence could be partially explained by the capacity of these
microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types
of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different
species.
Findings: Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter
spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid
interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus
5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface;
between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the
biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than
for Acinetobacter G3 (36%, 27% & 9% respectively).
Conclusions: Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of
biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to
their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the
ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not
observed in other Acinetobacter species.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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