The role of Zur-regulated lipoprotein A in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles in Acinetobacter baumannii

BMC Microbiology

article

Kim, Nayeong¹  Lee, Je Chul¹  Kim, Hyo Jeong¹  Oh, Man Hwan²  Kim, Se Yeon¹  Kim, Mi Hyun¹  Son, Joo Hee¹  Kim, Seung Il³  Shin, Minsang¹  Lee, Yoo Chul¹ 

[1] Department of Microbiology, School of Medicine, Kyungpook National University;Department of Nanobiomedical Science, Dankook University;Korea Basic Science Institute;Department of Bio-Analytical Science, University of Science and Technology (UST)

关键词: Acinetobacter baumannii;    Zur-regulated gene;    ZrlA;    Carboxypeptidase;    Outer membrane vesicle;   

DOI  :  10.1186/s12866-020-02083-0

学科分类：放射科、核医学、医学影像

来源: BioMed Central

【 摘 要 】

Zinc uptake-regulator (Zur)-regulated lipoprotein A (ZrlA) plays a role in bacterial fitness and overcoming antimicrobial exposure in Acinetobacter baumannii. This study further characterized the zrlA gene and its encoded protein and investigated the roles of the zrlA gene in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles (OMVs) in A. baumannii ATCC 17978. In silico and polymerase chain reaction analyses showed that the zrlA gene was conserved among A. baumannii strains with 97–100% sequence homology. Recombinant ZrlA protein exhibited a specific enzymatic activity of D-alanine-D-alanine carboxypeptidase. Wild-type A. baumannii exhibited more morphological heterogeneity than a ΔzrlA mutant strain during stationary phase. The ΔzrlA mutant strain was more susceptible to gentamicin than the wild-type strain. Sizes and protein profiles of OMVs were similar between the wild-type and ΔzrlA mutant strains, but the ΔzrlA mutant strain produced 9.7 times more OMV particles than the wild-type strain. OMVs from the ΔzrlA mutant were more cytotoxic in cultured epithelial cells than OMVs from the wild-type strain. The present study demonstrated that A. baumannii ZrlA contributes to bacterial morphogenesis and antimicrobial resistance, but its deletion increases OMV production and OMV-mediated host cell cytotoxicity.

【 授权许可】

CC BY|CC0