Abstract
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is an opportunistic pathogen causing urinary tract infection (UTI). Endolysin EN572-5 was identified in prophage KMB-572-E of the human isolate Streptococcus agalactiae KMB-572. The entire EN572-5 gene was cloned into an expression vector and the corresponding recombinant protein EN572-5 was expressed in Escherichia coli in a soluble form, isolated by affinity chromatography, and characterized. The isolated protein was highly active after 30 min incubation in a temperature range of − 20 °C to 37 °C and in a pH range of 5.5–8.0. The endolysin EN572-5 lytic activity was tested on different Streptococcus spp. and Lactobacillus spp. The enzyme lysed clinical GBS (n = 31/31) and different streptococci (n = 6/8), and also exhibited moderate lytic activity against UPEC (n = 4/4), but no lysis of beneficial vaginal lactobacilli (n = 4) was observed. The ability of EN572-5 to eliminate GBS during UTI was investigated using an in vitro model of UPSA. After the administration of 3 μM EN572-5, a nearly 3-log decrease of urine bacterial burden was detected within 3 h. To date, no studies have been published on the use of endolysins against S. agalactiae during UTI.
Key points
• A lytic protein, EN572-5, from a prophage of a human GBS isolate has been identified.
• This protein is easily produced, simple to prepare, and stable after lyophilization.
• The bacteriolytic activity of EN572-5 was demonstrated for the first time in human urine.
Graphical abstract
Funder
Slovenská Akadémia Vied
Slovak Academy of Sciences
Publisher
Springer Science and Business Media LLC
Subject
Applied Microbiology and Biotechnology,General Medicine,Biotechnology