Lactococcus garvieae has emerged as an important zoonotic pathogen. However, information regarding mechanisms and factors related to its pathogenicity is lacking. In the present study, we investigated the distribution and functionality of genes related to virulence factors in L. garvieae strains isolated from different niches (diseased fish, humans, meat and dairy products, vegetables), using both post-genomic and genotypic analysis. Putative genes encoding hemolysin, fibronectin-binding protein, and penicillin acylase were detected in all analyzed genomes/strains. Their expression was significantly induced by bile salt stress. Putative genes encoding bile salt hydrolase were found in a few strains from dairy and human sources, as well as the mobilizable tet genes. Finally, all genomes possessed a folate gene cluster, in which mutations in the dihydropteroate synthase gene (folP) could be related to sulfonamide resistance. To the best of our knowledge, this is the first study aimed to explore the pathogenic potential of L. garvieae through the analysis of numerous L. garvieae genomes/strains, coming from different sources. This approach allowed the detection of virulence-related genes not yet investigated in the species and the study of their expression after exposure to different environmental stresses. The results obtained suggest a virulence potential in some L. garvieae strains that can be exploited for survival in the human gastrointestinal tract.
- MeSH
- DNA bakterií genetika MeSH
- faktory virulence genetika MeSH
- genomika * MeSH
- Lactococcus genetika růst a vývoj patogenita MeSH
- lidé MeSH
- regulace genové exprese u bakterií * MeSH
- stanovení celkové genové exprese MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
UNLABELLED: How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in Streptococcus pneumoniae. We show that locZ is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division. IMPORTANCE: Bacterial cell division is a highly ordered process regulated in time and space. Recently, we reported that the Ser/Thr protein kinase StkP regulates cell division in Streptococcus pneumoniae, through phosphorylation of several key proteins. Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ. We show that LocZ is a new cell division protein important for proper septum placement and likely functions as a marker of the cell division site. Consistently, LocZ supports proper Z-ring positioning at midcell. LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.
- MeSH
- buněčné dělení * MeSH
- delece genu MeSH
- Enterococcus genetika MeSH
- Lactococcus genetika MeSH
- proteiny buněčného cyklu genetika metabolismus MeSH
- sekvenční homologie aminokyselin MeSH
- Streptococcus pneumoniae cytologie genetika fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Early childhood caries (ECC) has become a serious medical problem worldwide in the last decade. Bacterial microflora of the dental plaque and oral cavity is considered an important factor in the formation and progression of dental caries. The aim of this study was strain typing and comparison of bacterial isolates retrieved from caries lesions and root canal contents of the same teeth. In total, 18 pairs of presumptive streptococci and lactobacilli retrieved from dental caries and root canals isolated from ECC-affected children, were selected on the basis of biotyping results and rep-PCR fingerprinting with (GTG)5 primer. Strain typing was further done using the RiboPrinter microbial characterization system (DuPont Qualicon). The automated ribotyping determined 14 pairs of the strains (77.8 %) to be identical. The results obtained confirmed that identical bacterial strains colonized both the decayed dental surface and the necrotic content of the dental pulp cavity during the cariogenesis. Our finding supports the assumption that bacteria could penetrate through the damaged dental surface to the inner parts of the teeth.
- MeSH
- dítě MeSH
- DNA fingerprinting MeSH
- kavita zubní dřeně mikrobiologie MeSH
- Lactococcus klasifikace genetika izolace a purifikace fyziologie MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- předškolní dítě MeSH
- ribotypizace MeSH
- Streptococcus klasifikace genetika izolace a purifikace fyziologie MeSH
- techniky typizace bakterií MeSH
- zubní kaz mikrobiologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
