Differentiation of Species Combined into the Burkholderia cepacia Complex and Related Taxa on the Basis of Their Fatty Acid Patterns

Abstract

Using the established commercial system Sherlock (MIDI, Inc.), cellular fatty acid methyl ester analysis for differentiation among Burkholderia cepacia complex species was proven. The identification key based on the diagnostic fatty acids is able to discern phenotypically related Ralstonia pickettii and Pandoraea spp. and further distinguish Burkholderia pyrrocinia, Burkholderia ambifaria, and Burkholderia vietnamiensis.At present, nine Burkholderia species are combined into the Burkholderia cepacia complex (BCC) : B. cepacia, B. multivorans, B. cenocepacia, B. stabilis, B. vietnamiensis, B. dolosa, B. ambifaria, B. anthina, and B. pyrrocinia (2, 12-14). In some cases, the severity of BCC infection is closely connected with one particular species. The proper identification of likely BCC isolates is crucial for patients suffering from cystic fibrosis (CF) (9).Identification of BCC isolates to the species level based on the results obtained by genotypic methods, such as restriction fragment length polymorphism analysis of the recA gene or 16S rRNA genes (17, 18) and recA gene-based PCR (4), is mostly done with research tools provided in reference centers. Phenotypic testing is still frequently used in routine laboratories. Because of constantly changing taxonomy, such identification could be inaccurate. Databases of commonly used commercial kits are often incomplete and may even be insufficient to properly discern BCC isolates from other phylogenetically related isolates or from Ralstonia pickettii and Pandoraea spp. commonly isolated from clinical human sources.Cellular fatty analysis using semiautomated gas chromatography by the microbial identification system (MIS) Sherlock (MIDI, Inc., Newark, Del.) is a relatively rapid and cost-effective method widely available and suitable for clinical laboratories. Identification based on the species-specific differences in fatty acid composition in cell lipidic structure was proved to be a good taxonomic marker (15). Contrary to phenotyping, previous studies have shown that analysis of cellular fatty acid components was able to distinguish between the genera Burkholderia, Ralstonia, and Pandoraea (1,19). Fatty acids of the BCC are rather uniform; nevertheless, species-specific differences useful to separate B. anthina or B. ambifaria from B. cepacia and B. cenocepacia were observed (2, 13). So far there are no reports that include and compare the fatty acid compositions of all known BCC species and related taxa under standardized culture conditions. In this study, we tested whether comparing fatty acid profiles obtained on MIS Sherlock could yield the ability to sufficiently discriminate between BCC species and other closely related taxa.Type strains (Tables 1 and 2) and a set including 47 wellcharacterized clinical isolates recovered during a half-year survey in 2002 in two town hospitals and several ambulatory medical practices in our region (Ostrava, Czech Republic) were studied. Isolates (one per patient) originated primarily from non-CF patients (sputum, blood cultu...

Biofilm-forming bacteria with varying tolerance to peracetic acid from a paper machine

“…The wholecell fatty acid compositions of the group C isolates (Table 1) show that 2-hydroxy-tetradecanoic acid was practically absent but 3-hydroxy-tetradecanoic acid and 3-hydroxy-hexadecanoic acid were abundant (4-5%). This matches with the identiWcation of the isolates as members of the betaproteobacterial B. cepacia complex species other than B. pyrrocinia, B. ambifaria, or B. vietnamiensis [25].…”

Gas chromatography-mass spectrometry method for rapid identification and differentiation ofBurkholderia pseudomalleiandBurkholderia malleifrom each other,Burkholderia thailandensisand several members of theBurkholderia cepaciacomplex

“…First, the organism must be cultured under standardized growth conditions. This requirement stems from the fact that fatty acid composition is influenced by growth medium and incubation temperature (Krejci and Kroppenstedt ). Second, sample preparation for this method includes several time‐consuming and complicated steps (i.e.…”

Phenotypic and phylogenetic characterization of an abamectin-degrading bacterial strain isolated from a citrus orchard

“…However, it did not give clear evidence about the classification of strain GB-01. The high % of 18 0 fatty acid (5.1%) indicated that GB-01 should be closely related to B. vietnamiensis, because 3% value for this fatty acid is a typical characteristic of B. vietnamiensis species (Krejci and Kroppenstedt, 2006). However, phylogenetic analysis of 16S rRNA and recA genes (discussed below) of strain GB-01 illustrated its close relationship with B. ambifaria and B.diffusa rather than B. vietnamiensis.…”

“…The comparison of fatty acid profiles of strain GB-01 with some type strains of genus Burkholderia and other closely related genera, expressed as relative abundance (%), is shown in Table 3. Krejci and Kroppenstedt (2006) and Sheu et al (2013). ** It was detected as Summed feature 3, that may comprise C 15:0 iso 2OH, and/or C 16:1 ω7c, and/or C 16:1 ω6c or any combination of these.…”