The effect of erythromycin in Macrolide-Resistant Bordetella pertussis: Inhibitory on Growth, Toxin Expression, and Virulence

Abstract

The macrolide-resistant Bordetella pertussis (MRBp) has appeared in Asian and even been prevalent in China. Causing of the antibiotic sensitivity test is not carried out in the clinic application, macrolide is still the first choice of antibiotic when MRBp infection. The macrolide therapy for pertussis needs to be revised. Macrolide is always shown a positive effect on other macrolide-resistant bacterium infenction in clinical application. However, the mechanism of macrolide on MRBp is unclear.This study conducted a representative isolate BP19147 (ptxP1/fhaB3-MRBp) under a series of sub-inhibitory concentrations of erythromycin. We measured the growth curve, biofilm formation and autoaggregation assay under SS broth. The relative genes expression was detected by RT-qPCR. The proteomics was detected by label-fee DIA. The MR isolate BP19147 is inhibited by sub-MIC of erythromycin and has a concentration-dependent effect. From the proteomics results, the Ptx, FHA, and pertactin do not show a statistical difference (p >0.05). Other virulence factors (including Dnt, Cya, and et al) show the statistical difference (p <0.05). In the KEGG enrichment, the BvgAS system, biofilm formation, and some adaptive systems are inhibited by erythromycin. The sub-MIC of erythromycin may reduce the virulence of MRBp, which will provide a theoretical basis for the rational use of erythromycin for MRBp infection and help the development of new antibiotics.