STRAIN OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA) CHARACTERIZED BY RESISTANCE TO CEFTAROLINE AND USED AS A CONTROL TEST CULTURE TO DETERMINE SENSITIVITY TO BETA-LACTAM ANTIBIOTICS (VARIANTS) Russian patent published in 2023 - IPC C12N1/20 C12R1/445 

FIELD: biotechnology.

SUBSTANCE: methicillin-resistant strain of Staphylococcus aureus (MRSA) SA0422 cpt is characterized by a mec-independent mechanism — resistance to ceftaroline. The methicillin-resistant strain of Staphylococcus aureus (MRSA) SA0146 cpt is characterized by resistance to ceftaroline due to mutations in the mecA gene. The strains were obtained during in vitro selection for 40 passages at increasing concentrations of ceftaroline and are characterized by a high level of resistance to ceftaroline (MIC≥32 µg/ml). The initial strains are clinical isolates (strain SA0146 cpt — genotype ST228; strain SA0422 cpt — genotype ST8) isolated in 2012 from patients with staphylococcal infections and sensitive to ceftaroline. The SA0146 cpt strain has mutations in the mecA gene (Glu447Lys, Tyr446Asn), the SA0422 cpt strain is characterized by a mec-independent mechanism of resistance to ceftaroline and the phenotype is determined by mutations in the c-di-AMP secondary signal messenger metabolism system (gdpP gene). The strains were deposited with the State Collection of Pathogenic Microorganisms and Cell Cultures (GKPM-Obolensk) under the following registration numbers: B-9990 (strain SA0146 cpt) and B-9991 (SA0422 cpt).

EFFECT: strains can be used as test cultures to assess sensitivity to antibacterial drugs; to search for new targets in the cell in order to develop new antibacterial drugs; to test new potential antimicrobial compounds.

2 cl, 3 dwg, 3 tbl, 3 ex