Journal: BMC Microbiology

Article Title: Overexpression of outer membrane protein A (OmpA) increases aminoglycoside sensitivity in mycobacteria

doi: 10.1186/s12866-024-03632-7

Figure Lengend Snippet: OmpA works as a porin protein for aminoglycosides’ uptake. ( A ) Spermidine affects the growth inhibition of streptomycin on Ms. Spermidine, as a porin inhibitor, can bind to porin and reduce the permeability of protein channels, spm: spermidine. The growth of Ms under streptomycin pressure in the presence and absence of spermidine was detected by measuring absorbance values at 600 nm. ( B ) Cell wall permeability assay. Mycobacterium smegmatis was incubated with 2 µg/ml of hydrophilic substrate ethidium bromide and the fluorescence intensity was measured with excitation light at 540 nm and emission light at 630 nm. ( C ) The model of OmpA in uptakes of aminoglycosides. The OmpA allows the transition of hydrophilic small-molecule compounds. Overexpressing OmpA can transport more hydrophilic antibiotics such as the aminoglycosides into the bacteria, which leads to the increase of Mycobacteria’s sensitivity to the antibiotics

Article Snippet: Antibiotics used in this study: Aminoglycosides: streptomycin (STR, Topscience, T0060), amikacin (AMI, Topscience, T1013), gentamicin (GEN, Topscience, T1326); Rifamycins: rifampicin (RIF, Sigma, R3501), rifabutin (RIFB, Topscience, T1501), rifapentine (RIFP, Topscience, T1629); isoniazid(INH, Sigma V900688);ethambutol (EMB, Topscience, T0810); Fluoroquinolones: ofloxacin (OFX, Topscience, T0902).

Techniques: Inhibition, Permeability, Incubation, Fluorescence, Bacteria