Positive controls in the detection of genes of resistance to tetracyclines in bacteria of veterinary interest
Because the etiologic agents are mainly multi-resistant bacteria, the treatment of nosocomial infections is increasingly complicated. In addition, because bacterial resistance is encoded by genes, it becomes necessary to know and update their frequencies and to guide the control of antimicrobial resistance in hospitals.
Currently, the Polymerase Chain Reaction (PCR) is the molecular tool used for the detection of these genes, but positive controls are needed for the proper interpretation of their results.
Therefore, the objective of this study was to obtain two positive controls for tetracycline resistance genes: tet (A) and tet (B) from Pseudomonas aeruginosa and Pantoea agglomerans, two bacterial strains resistant to tetracycline. These genes were detected by PCR, sequenced and compared with data from Gen Bank. ®.
The results obtained using the Clustal Ω and BLAST program indicated a nucleotidic identity percentage (NIP) higher than 90% for tet (B) gene, meanwhile lower nucleotidic identity for tet (A) gene is controversial.
Thus, the presence of the tet (B) gene was confirmed in the studied strains and its utilization as positive controls can be suggested. The obtaining of strain that may be used as positive control for tet(A) gene was not achieved, however new primers are proposed.