Biofilm formation by Mycobacterium avium isolates originating from humans, swine and birds

Tone Johansen,Sigrun Nilsen,Ingrid Olsen,Berit Djønne,Gudmund Holstad,Angelika Agdestein

doi:10.1186/1471-2180-9-159

Tone Johansen, Sigrun Nilsen + Show 4 more

Open Access

https://doi.org/10.1186/1471-2180-9-159

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Journal: BMC microbiology	Publication Date: Jan 1, 2009
Citations: 95	License type: cc-by

Affiliation: Norwegian Veterinary Institute

Abstract

BackgroundMycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all over the world including from biofilms in water distribution systems. The aim of this study was to examine isolates of M. avium subsp. avium and M. avium subsp. hominissuis of different origin for biofilm formation and to look for correlations between biofilm formation and RFLP-types, and to standardise the method to test for biofilm formation. In order to determine the best screening method, a panel of 14 isolates of M. avium subsp. avium and M. avium subsp. hominissuis, were tested for their ability to form biofilm in microtiter plates under different conditions. Subsequently, 83 additional isolates from humans, swine and birds were tested for biofilm formation. The isolates were tested for the presence of selected genes involved in the synthesis of glycopeptidolipids (GPLs) in the cell wall of M. avium, which is believed to be important for biofilm formation. Colony morphology and hsp65 sequvar were also determined.ResultsNine isolates from swine produced biofilm. There was a significant higher frequency of porcine isolates forming biofilm compared to human isolates. All isolates were previously characterised by IS1311- and IS1245-RFLP typing. The ability to form biofilm did not correlate with the RFLP-type, hsp65 sequevar, colony morphology or the presence of gene sequences related to GPL synthesis.ConclusionThe observed differences in biofilm forming abilities between porcine and human isolates raises questions regarding the importance of biofilm formation for infectious potential. The optimised method worked well for screening of multiple isolates.

Highlights

Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all over the world including from biofilms in water distribution systems
Our study demonstrated that transmission between animals and/or humans of identical isolates of M. avium is uncommon in Norway, and that transmission of M. avium from the environment to humans and animals is more likely [12]
In a study performed by Krzywinska and Schorey, the authors found differences between M. avium strain A5 and strain 104 regarding the GPL biosynthesis cluster

Summary

Introduction

Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all over the world including from biofilms in water distribution systems. 83 additional isolates from humans, swine and birds were tested for biofilm formation. Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis [1,2,3]. Various molecular tools have been used to characterise isolates of M. avium, including restriction fragment length polymorphism (RFLP) [9], sequencing of the hsp gene [10] and multilocus sequence analysis (MLSA) [11]. We characterised M. avium isolates from birds, swine and humans in Norway by IS1311- and IS1245-RFLP typing. The results are in accordance with other studies [13,14,15]

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