Design and High Expression of Non-glycosylated Lysostaphins in and Their Pharmacodynamic Study.

Lysostaphin is an effective antimicrobial agent to , especially for the methicillin-resistant (MRSA) and multidrug-resistant (MDRSA). In this study, the seven lysostaphin derived mutants (rLys) were designed to overcome the barrier of glycosylation during expression in . Among them, 127A and 127A232Q had highest antimicrobial activity (MIC values 0.07-0.3 μM) to than others and the commercial lysostaphins (1-15.8 times). There was no glycosylation during the expression in 5-L fermenter level, with the high yield of 1315 mg/L (127A) and 1141 mg/L (127A232Q), respectively. Meanwhile, 127A and 127A232Q effectively killed 99.9% of at low concentration (1 × MIC) within 30 min, without the regrowth of pathogen. They also showed low toxicity, high pH and temperature stability. The results of therapeutic effect of 127A and 127A232Q against high virulent CVCC546 showed that 127A and 127A232Q increased the survival rate of infected mice up to 100% at the dose of 10 mg/kg than the untreated group, reduced the bacterial translocation by 5-7 log CFU (over 99%) in organs compared to the untreated group and alleviated multiple-organ injuries (liver, kidney and spleen). These data indicated that the non-glycosylated lysostaphin 127A and 127A232Q may be a promising therapeutic agent against MDR staphylococcal infections.