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Abstract Background Staphylococcus argenteus is a new specie positive coagulase staphylococci. We investigate the presence of S. argenteus in isolates previously classified as S. aureus, obtained from the milk of cows with mastitis in Brazil. Results Among 856 S. aureus tested in chocolate agar, tryptone soya agar and salt egg yolk agar, white or colorless colonies were observed in 185 (21.6%) isolates. Regarding the ctrOPQMN operon, 111 (60%) presented the complete cluster. Despite some missing genes in this cluster, the remaining strains (74) were confirmed as S. aureus using the nrps gene. Conclusions As far as we know, this is the first review of S. aureus collection in Brazil and S. argenteus does not appear to be a significant problem in Brazilian herds.

Background: Staphylococcus argenteus is a new specie positive coagulase staphylococci. We investigate the presence of S. argenteus in isolates previously classified as S. aureus, obtained from the milk of cows with mastitis in Brazil. Results: Among 856 S. aureus tested in chocolate agar, tryptone soya agar and salt egg yolk agar, white or colorless colonies were observed in 185 (21.6%) isolates. Regarding the ctrOPQMN operon, 111 (60%) presented the complete cluster. Despite some missing genes in this cluster, the remaining strains (74) were confirmed as S. aureus using the nrps gene. Conclusions: As far as we know, this is the first review of S. aureus collection in Brazil and S. argenteus does not appear to be a significant problem in Brazilian herds. [ABSTRACT FROM AUTHOR]

Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg−1 and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg−1) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg−1). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed.

The object of this study was to find and characterise streptomycete isolates with antimicrobial activity accomplished by the agar plug method against phytopathogenic species. The test-microorganisms were selected according to their importance in agriculture. All of them belong to phytopathogenic species which reduce yields of agriculturally important plants worldwide. A total number of four phytopathogenic bacteria (Xanthomonas campestris (CCM 22), Pseudomonas syringae (CCM 2868), Erwinia amylovora (CCM 1114), Clavibacter michiganensis subsp. sepedonicus (CCM 7014)) and four phytopathogenic fungi (Botrytis cinerea, Fusarium poae, Alternaria tenuissima, Alternaria arborescens) were used for this experiment. Overall twenty streptomycete isolates showed antimicrobial activity against at least two of the test-microorganisms. These active isolates were subsequently characterized. Streptomycete isolates were observed for morphological characteristics, such as morphology and colour of aerial and substrate mycelium, colour of diffusible pigments, production of melanoid pigments on peptone-yeast extract iron agar and sporophore and spore chain morphology following the International Streptomyces Project. Genes coding polyketide synthase (PKS-I) and nonribosomal peptide synthetase (NRPS), which are considered to responsible for the synthesis of large number of biologically active compounds, like antibiotics and antifungals, that are produced by Streptomyces species largely, were screened. The occurrence of these genes in the genome of our isolates was in accordance with results from antimicrobial activity analysis. Classification to genus Streptomyces were confirmed by DNA sequencing. [ABSTRACT FROM AUTHOR]

Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg−1 and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg−1) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg−1). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed. [ABSTRACT FROM AUTHOR]