Biofilm production and other virulence factors in Streptococcus spp. isolated from clinical cases of bovine mastitis in Poland

Abstract

BackgroundMastitis is a common disease in dairy cattle throughout the world and causes considerable economic losses each year. An important aetiological agent of this disease is bacteria of the genus Streptococcus; hence, exploring the mechanisms of virulence in these bacteria is an extremely important step for the development of effective prevention programmes. The purpose of our study was to determine the ability to produce biofilm and the occurrence of selected invasiveness factors among bacteria of the genus Streptococcus isolated from cattle with the clinical form of mastitis in northeastern Poland.ResultsMost of the isolates analysed demonstrated an ability to produce biofilm (over 70%). Virulence genes were searched for in the three most common streptococci in our experiment: S. agalactiae, S. uberis and S. dysgalactiae. For S. agalactiae, only four genes were confirmed: rib (33%), cylE (78%), bca (37%), and cfb (100%). The genes pavA, scpB, bac and lmb were not present in any of the tested strains. The dominant serotypes of the species were Ia (n = 8) and II (n = 8), in addition to some strains that were not classified in any of the groups (n = 6). Out of the eight selected genes for S. uberis (sua, pauA/skc, gapC, cfu, lbp, hasA, hasB, hasC), only one was not found (lbp). Finally, two genes were chosen for S. dysgalactiae (eno and napr), and their presence was confirmed in 76% and 86% of the strains, respectively.ConclusionsThe experiment showed that strains of Streptococcus spp. isolated from dairy cattle with clinical cases of mastitis in the northeastern part of Poland possess several invasiveness factors that can substantially affect the course of the disease, and this should be considered when developing targeted prevention programmes.

Sequence Types and Antimicrobial Resistance Profiles of Streptococcus uberis Isolated From Bovine Mastitis

“…Moreover, further molecular mechanisms that may promote the higher prevalence of specific STs such as virulence factors, were not analyzed in this study. Additional investigations are required to characterize such factors in various S. uberis STs, including factors affecting biofilm formation (21), host cell invasion, survival in the host environment or evasion of host immune response, respectively (18, 22, 23).…”

“…Ignoring potential interspecies differences in pharmacokinetics as well as the fact that S. uberis is a cattle-adapted species, we attempted to determine and compare resistance rates using breakpoints published for human viridans streptococci (16), as described previously for the pan-European monitoring program VETPATH (21). There, resistance rates of 0.0% and 20.2% for penicillin and erythromycin, respectively, were calculated for S. uberis .…”

Increasing Resistance and Changes in Distribution of Serotypes of Streptococcus agalactiae in Poland

“…In vitro, it depends on various environmental factors, including the type of a medium used, the conditions of pH, temperature, and osmolarity [ 50 , 51 , 52 , 53 ]. Methodological differences and various interpretation criteria applied in different studies make the data comparisons difficult [ 26 , 51 , 54 , 55 , 56 ]. Ho and co-authors evaluated the ability to form biofilm in 80 GBS strains derived from colonization from pregnant women, classifying them into groups of very strong (51%), strong (28%), and moderate biofilm producers (18%) and strains which do not produce biofilm (4%).…”

Isolation of Streptococcus agalactiae in a female llama (Lama glama) in South Tyrol (Italy)

“…In fact, microorganisms inside biofilms have increased resistance to antimicrobial agents and disinfectants, indicating the pathogenicity potential in the isolated strains. The analysis of virulence factors production was not performed in this report, though previous reports have highlighted the potential of virulence factors production by S. agalactiae in bovine mastitis [ 31 ]. Furthermore, biofilm formation appears to be a prerequisite for colonization of the bovine mammary gland.…”