rpoB gene sequence-based identification of Staphylococcus species

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Taxonomy

Background:

• Accurate identification of bacterial species is crucial for clinical and research purposes.
• Traditional methods for Staphylococcus species identification can be time-consuming and may lack precision.
• The rpoB gene, encoding the beta subunit of RNA polymerase, is a potential target for molecular identification.

Purpose of the Study:

• To determine the complete and partial sequences of the rpoB gene across various Staphylococcus species.
• To establish a phylogenetic framework based on rpoB gene sequences.
• To develop and validate a novel molecular method for accurate Staphylococcus species identification.

Main Methods:

• Sequencing of the complete rpoB gene for four Staphylococcus species and partial sequences for 27 additional species.
• Phylogenetic analysis using rpoB gene sequences and comparison with existing taxonomic data (DNA-DNA hybridization, 16S rDNA, HSP60).
• Development of a Polymerase Chain Reaction (PCR) and direct sequencing method targeting a 751-bp amplicon of the rpoB gene.

Main Results:

• Complete rpoB sequences ranged from 3,452 to 3,845 bp with 36.8 to 39.2% GC content.
• Partial sequences showed high interspecies homology (71.6 to 93.6%) and low intraspecific divergence (0.08 to 0.8%).
• Phylogenetic analysis largely agreed with previous studies; the developed PCR-sequencing method accurately identified 10 Staphylococcus isolates in blind tests, with no false positives from non-Staphylococcus bacteria.

Conclusions:

• The established staphylococcal rpoB sequence database supports phylogenetic analysis and species delineation.
• Partial sequencing of the rpoB gene provides a reliable and accurate molecular method for identifying Staphylococcus isolates.
• This method offers a valuable tool for bacterial identification in clinical and research settings.