Multilocus sequence typing characterizes diversity of Ureaplasma diversum strains, and intra-species variability induces different immune response profiles

Yasmin M F S Andrade,Aline T Amorim,Ellunny C Queiroz,Bruno L Bastos,Maysa S Barbosa,Lucas M Marques,Guilherme B Campos,Jorge Timenetsky,Izadora S Rezende,Manoel N Santos-Junior,Ícaro B S Silva

doi:10.1186/s12917-020-02380-w

Abstract

BackgroundUreaplasma diversum is a pathogen found in the genital tract of cattle and associated with genital disorders such as infertility, placentitis, abortion, birth of weak calves, low sperm motility, seminal vesiculitis and epididymitis. There are few studies evaluating the genetic diversity of U. diversum strains and their influence on the immune response in cattle. Therefore, to better understand genetic relationships of the pathogenicity of U. diversum, a multilocus sequence typing (MLST) scheme was performed to characterize the ATCC 49782 strain and another 40 isolates recovered from different Brazilian states.ResultsPrimers were designed for housekeeping genes ftsH, polC, rpL22, rpoB, valS and ureA and for virulence genes, phospholipase D (pld), triacylglycerol lipase (tgl), hemolysin (hlyA), MIB-MIP system (mib,mip), MBA (mba), VsA (VsA) and ribose transporter (tABC). PCRs were performed and the targeted gene products were purified and sequenced. Sequence types (STs), and clonal complexes (CCs) were assigned and the phylogenetic relationship was also evaluated. Thus, a total of 19 STs and 4 CCs were studied. Following the molecular analysis, six isolates of U. diversum were selected, inoculated into bovine monocyte/macrophage culture and evaluated for gene expression of the cytokines TNF-α, IL-1, IL-6, IL-10 and IL-17. Differences were detected in the induction of cytokines, especially between isolates 198 and BA78, promoted inflammatory and anti-inflammatory profiles, respectively, and they also differed in virulence factors.ConclusionIt was observed that intra-species variability between isolates of U. diversum can induce variations of virulent determinants and, consequently, modulate the expression of the triggered immune response.

Highlights

Ureaplasma diversum is a pathogen found in the genital tract of cattle and associated with genital disorders such as infertility, placentitis, abortion, birth of weak calves, low sperm motility, seminal vesiculitis and epididymitis
Differences were detected in the induction of cytokines, especially between isolates 198 and BA78, promoted inflammatory and anti-inflammatory profiles, respectively, and they differed in virulence factors
The 45 isolates were classified into 19 Sequence types (STs), and some STs were grouped into 4 Clonal complexes (CC)

Summary

Introduction

Ureaplasma diversum is a pathogen found in the genital tract of cattle and associated with genital disorders such as infertility, placentitis, abortion, birth of weak calves, low sperm motility, seminal vesiculitis and epididymitis. Ureaplasma diversum, the only ureaplasma found in cattle, was first isolated in 1967 and produces urease and hydrolyzes urea in ammonia, and has no cell wall or mobility structures [1] It invades epithelial cells of the respiratory and genital tracts from cattle, and is related to reproductive diseases by interfering with implantation and embryonic development [2]. Disorders such as vulvovaginitis, salpingitis, endometritis, fetal alveolitis, infertility, abortion or birth of weak calves in cows and seminal vesiculitis, epididymitis in bulls, are strongly associated with U. diversum [2]. Ureplasma diversum has been demonstrated to be able to invade and induce apoptosis in HEp-2 cells, invade sperm leading to loss of semen quality, as well as express molecules that trigger immune response by proinflammatory cytokine production (IL-1α, IL-1β, IL-6, IL-8 and TNF-α), opsonization by antibodies and complement system, and infiltration of neutrophils and macrophages in infected sites [4,5,6]

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