Which statement about beta- lactamases is not right?
About 200 different lactamases identified ;
B. They can break the beta- lactam ring of the antibiotics ;
C. Most enzymes are encoded by the genes in the chromosome frequently;
D. They can spread among bacteria by horizontal gene transfer.
查看答案
Which antibiotics can not be inactivated by beta- lactamase produced by bacteria?
A. penicillin,
B. streptomycin,
C. vacomycin,
D. Cephalosporin.
Which type of point mutation in chromosomal gene is less likely to alter pore proteins to prevent the entry of drug into cytoplasm.
A. silent mutation;
B. missense mutation,
C. nonsense mutation;
D. Frameshift insertion.
Which protein with mutations in its gene could not inducedrug resistance?
A. porin in the outer membrane;
B. P12 of 30S ribosome ,
C. β-unit of RNA polymerase ;
D. lipoprotein in cell wall.
Which mechanism will confer sulfonamide resistance in thebacteria?
A. Bacteria absorb folic acid from the environment;
Bacteria alter P12 of 30S ribosome ,
C. Bacteria with mutatedβ-unit of RNA polymerase ;
D. Bacteria produce beta-lactamases.
微信支付 
支付宝支付