confers_resistance_to_antibiotic cefoxitin ciprofloxacin tetracycline ceftriaxone confers_resistance_to_antibiotic chloramphenicol cefotaxime gene conferring resistance via absence moxalactam Serratia marcescens Omp1 Omp1 is an outer membrane porin that confers resistance by absence in S. marcescens. Knockout, deletion or other inhibition of the omp1 gene confers resistance to certain beta-lactamase antibiotics - including Cefoxitin, Ceftriaxone, Cefotaxime, and Moxalactam - as well as Ciprofloxacin, Tetracycline, and Chloramphenicol, by preventing passage of the antibiotic into the cell. ARO:3004128 Smar_Omp1 antibiotic_resistance General Bacterial Porin with reduced permeability to beta-lactams