Characterization of the brewery spoilage bacterium Obesumbacterium proteus by automated ribotyping and development of PCR methods for its biotype 1

Abstract

Aims: To study the ability of automated ribotyping to characterize Obesumbacterium proteus and Hafnia alvei, to design primers and to evaluate standard end‐point and real‐time PCR for the detection of O. proteus biotype 1 in beer and in brewers's yeast‐containing samples. Methods and Results: Automated ribotyping was carried out using the standard method with EcoRI and PvuII. The digestions with both enzymes clearly differentiated O. proteus biotypes 1 and 2 and H. alvei. PCR primers were designed according to the 16S rRNA gene sequence of the O. proteus type strain. Two primer sets (Obs137–Obs558 and Obs137–Obs617) detected O. proteus biotype 1 and H. alvei but not O. proteus biotype 2 or other tested beer spoilage bacteria (40 species) in the end‐point and real‐time PCR, indicating their high specificity. The detection limit for O. proteus was 160–1600 CFU 100 ml−1 beer in the end‐point PCR reactions and ≤160 CFU 100 ml−1 beer in the real‐time PCR reactions. More cells (from 16 to 3200) were needed for detection in the presence of brewer's yeast cells. Conclusions: Automated ribotyping is a useful tool to characterize and identify O. proteus and H. alvei isolates. The designed primers are suitable for the rapid detection of O. proteus biotype 1 and H. alvei in brewery samples by PCR. Significance and Impact of the Study: Automated ribotyping and PCR could improve microbiological quality control in breweries by facilitating the detection, identification and tracing of spoilage bacteria.

Genome Sequence of the Thermotolerant Foodborne Pathogen Salmonella enterica Serovar Senftenberg ATCC 43845 and Phylogenetic Analysis of Loci Encoding Increased Protein Quality Control Mechanisms

“…5) (1–3). Bacterial species that possess TLPQC-2 are of great interest to food industry and human health communities, as many are relevant to food safety such as Obesumbacterium proteus as brewery yeast contaminants (34) and C. sakazakii as infant formula contaminants (1). Given that a number of TLPQC-2 loci are found on plasmids, the potential exists for transmission and subsequent conferring of heat resistance to foodborne pathogens.…”

The changing face of microbial quality control practices in the brewing industry: Introducing mass spectrometry proteomic fingerprinting for microbial identification

“…Eleven L. casei strains exhibited eight sub-patterns, three L. coryneformis strains formed two sub-groups, in 10 L. plantarum strains four ribotypes could be distinguished and 11 L. lindneri strains clustered into five types (37). Further studies successfully applied ribotyping for the identification of Pectinatus cerevisiiphilus (34), P. frisingensis (34,35), Megasphaera cerevisiae (35) and Obesumbacterium proteus (36). FISH is a straightforward protocol compared with the method of ribotyping.…”

Gram-negative spoilage bacteria in brewing

“…Automated ribotyping Jespersen and Jakobsen (1996), Maugueret and Walker (2002) and Koivula et al (2006). MacConkey agar/broth 2.…”