Draft genome sequence of Staphylococcus agnetis 4244, a strain with gene clusters encoding distinct post-translationally modified antimicrobial peptides.

OBJECTIVES: Here we report the draft genome sequence of Staphylococcus agnetis 4244, a strain involved in bovine mastitis, and its ability to inhibit different species of antibiotic-resistant Gram-positive bacteria owing to bacteriocin production. METHODS: An Illumina MiSeq platform was used for genome sequencing. De novo genome assembly was done using the A5-miseq pipeline. Genome annotation was performed by the RAST server, and mining of bacteriocinogenic gene clusters was done using the BAGEL4 and antiSMASH v.5.0 platforms. Investigation of the spectrum of activity of S. agnetis 4244 was performed on BHI agar by deferred antagonism assay. RESULTS: The total scaffold size was determined to be 2 511 708 bp featuring a G+C content of 35.6%. The genome contains 2431 protein-coding sequences and 80 RNA sequences. Genome analyses revealed three prophage sequences inserted in the genome as well as several genes involved in drug resistance and two bacteriocin gene clusters (encoding a thiopeptide and a sactipeptide) encoded on the bacterial chromosome. Staphylococcus agnetis 4244 was able to inhibit all 44 strains of antibiotic-resistant Gram-positive bacteria tested in this study, including vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA) and other antibiotic-resistant staphylococcal strains. CONCLUSION: This study emphasises the potential biotechnological application of this strain for production of bacteriocins that could be used in the food industry as biopreservatives and/or in medicine as alternative therapeutic options against VRE, MRSA, vancomycin-intermediate S. aureus and other antibiotic-resistant Gram-positive bacteria, including biofilm-forming isolates. It also provides some genetic features of the draft genome of S. agnetis 4244.

Characterization of biofilms and antimicrobial resistance of coagulase-negative Staphylococcus species involved with subclinical mastitis.

Biofilm formation is a central feature to guarantee staphylococcal persistence in hosts and is associated with several diseases that are difficult to treat. In this research paper, biofilm formation and antimicrobial susceptibility were investigated in staphylococcal strains belonging to several species. These strains were isolated from the milk of cows with subclinical mastitis and most of them were coagulase-negative, with the prevalence of Staphylococcus chromogenes. High genetic diversity was observed among the strains by pulsed field gel electrophoresis. Antimicrobial resistance was assessed by disk diffusion and more than 50% of the strains were resistant to ampicillin and penicillin G, with multi-resistance profiles (13.6%) also being observed. Most strains (65.9%) formed biofilms when cultivated in BHI supplemented with 1% glucose. Most strains (72.7%) carried the intercellular adhesion gene (icaA), while less than half (36.3%) carried the biofilm-associated protein gene (bap). Concentrations of up to 10xMIC of erythromycin and tetracycline were not sufficient to suppress cell viability in preformed biofilms. Our results revealed that a genetically diverse group of biofilm-forming Staphylococcus species can be involved in subclinical mastitis. Since high antimicrobial concentrations cannot eradicate biofilm cells in vitro, their use in dairy animals may be ineffective in controlling infections, while supporting selection of resistant microorganisms. These data reinforce the need for alternative therapies aiming at disrupting biofilms for effective disease control.

Draft genome sequence of Staphylococcus agnetis 3682, the producing strain of the broad-spectrum lantibiotic agneticin 3682.

OBJECTIVES: Here we report the draft genome sequence of Staphylococcus agnetis 3682, a strain producing agneticin 3682, a broad-spectrum lantibiotic with potential medical applications. The inhibitory activity of S. agnetis 3682 against multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA) isolates involved in human infections was also investigated. METHODS: A sequencing library was constructed using a Nextera XT DNA Library Preparation Kit. An Illumina MiSeq system was used to perform whole-genome shotgun sequencing. De novo genome assembly was performed using the A5-miseq pipeline. Staphylococcus agnetis 3628 genome annotation was performed by the RAST server, and BAGEL4 and antiSMASH v.4.0 platforms were used for mining bacteriocin gene clusters. The inhibitory activity of S. agnetis 3682 against 20 multidrug-resistant MRSA strains involved in human infections in two Brazilian hospitals was determined by the deferred antagonism assay on brain-heart infusion (BHI) agar plates. RESULTS: The total scaffold size was determined to be 2 502 817bp with a G+C content of 35.6%. Genome analyses revealed 2437 coding sequences, 76 RNA genes, 27 genes involved in drug resistance and 2 bacteriocinogenic gene clusters (for agneticin 3682 and hyicin 4244). Staphylococcus agnetis 3682 inhibited 80% of the MRSA isolates tested. CONCLUSION: This study describes the main features of the draft genome of S. agnetis 3682, a strain producing the first bacteriocin (agneticin 3682) reported in this species. A second gene cluster encoding a sactipeptide was also found in the bacterial chromosome. Agneticin 3682 shows a new potential application against clinical MRSA isolates.

Draft Genome Sequence of Staphylococcus aureus 4185, a Strain That Produces Aureocyclicin 4185.

The draft genome sequence of the aureocyclicin 4185-producing strain Staphylococcus aureus 4185 is presented. The assembly contains 2,789,721 bp and a G+C content of 32.8%. Genome analysis allowed us to determine the complete sequence of the bacteriocinogenic plasmid pRJ101 and to find another bacteriocin gene cluster encoded on the bacterial chromosome.