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Yersinia enterocolitica is a Gram-negative pathogen frequently associated with swine and pork products. Despite its global importance, little is known about the genomic characteristics of Y. enterocolitica in Brazil. Furthermore, the antimicrobial resistance (AMR) in Y. enterocolitica has been associated to be driven by horizontal gene transfer, especially in environments with intensive antimicrobial use. This study aims to investigate the phylogenetic and population structure of Y. enterocolitica , and antimicrobial resistance and virulence gene distribution using genome sequences to compare isolates obtained in Brazil with other isolates deposited in online databases. In this study, a total of 998 high-quality genomes from Y. enterocolitica deposited in the National Center for Biotechnology Information (NCBI) were evaluated for pangenome using the Roary software with MAFFT for alignment. Pangenome analysis and phylogenetic inference were also performed on a subset of 837 genomes from isolates obtained from both pig and human. The analyses followed the procedures determined by ModelTest-NG. ABRicate with PlasmidFinder database, Virulence Factor Database (VFDB) and CARD database were used to investigate plasmid markers, virulence genes and resistance genes. Comparative analysis with international strains from public databases suggests that specific Y. enterocolitica strains circulate in Brazil. Swine and human isolates from Brazil were consistently grouped together, suggesting a strong zoonotic link. Additionally, the study underscores the correlation between antimicrobial use in pig farming and resistance gene prevalence. Our findings contribute to the understanding of Y. enterocolitica epidemiology in Brazil and emphasize the importance of genomic surveillance under the One Health approach to prevent foodborne diseases and combat antimicrobial resistance.

Hantaviruses are members of the family Bunyaviridaeandare an emergingcause of diseaseworldwidewithhighlethalityin the Americas. In Brazil, thediagnosis forhantaviruses is basedonimmunologictechniquesassociatedwithconventionalRT-PCR.Anovelone-stepSYBRGreenreal-timeRT-PCRwasdevelopedfor the detectionandquantitationofAraraquarahantavirus(ARAV)and Rio Mamore hantavirus (RIOMV). Thedetectionlimitof assay was 10copies/µLofRNA in vitro transcribed of segment S. The specificity of assay was evaluatedbymeltingcurveanalysis, which showed thattheAraraquaravirusamplifiedproductgenerate dameltpeak at80.83±0.89°C without generating primer-dimersornon-specificproducts.The assay was more sensitive than conventional RT-PCR and we detected two samples undetected by conventional RT-PCR. The one-step SYBR Green real-time quantitative RT-PCR is specific, sensible and reproducible, which makes it a powerful tool in both diagnostic applications and general research of ARAVand RIOMVand possibly other Brazilian hantaviruses.

Pediococcus pentosaceus ST65ACC was obtained from a Brazilian artisanal cheese (BAC) and characterized as bacteriocinogenic. This strain presented beneficial properties in previous studies, indicating its potential as a probiotic candidate. In this study, we aimed to carry out a genetic characterization based on whole-genome sequencing (WGS), including taxonomy, biotechnological properties, bacteriocin clusters and safety-related genes. WGS was performed using the Illumina MiSeq platform and the genome was annotated with the Prokaryotic Genome Annotation (Prokka). P . pentosaceus ST65ACC taxonomy was investigated and bacteriocin genes clusters were identified by BAGEL4, metabolic pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and safety-related genes were checked. P. pentosaceus ST65ACC had a total draft genome size of 1,933,194 bp with a GC content of 37.00%, and encoded 1950 protein coding sequences (CDSs), 6 rRNA, 55 tRNA, 1 tmRNA and no plasmids were detected. The analysis revealed absence of a CRISPR/Cas system, bacteriocin gene clusters for pediocin PA-1/AcH and penocin-A were identified. Genes related to beneficial properties, such as stress adaptation genes and adhesion genes, were identified. Furthermore, genes related to biogenic amines and virulence-related genes were not detected. Genes related to antibiotic resistance were identified, but not in prophage regions. Based on the obtained results, the beneficial potential of P. pentosaceus ST65ACC was confirmed, allowing its characterization as a potential probiotic candidate.

Pediococcus pentosaceus ST65ACC is a bacteriocinogenic lactic acid bacteria (LAB) isolated from Brazilian artisanal cheese that is capable of inhibiting different food pathogens, mainly Listeria monocytogenes. The production of bacteriocins can be influenced by several growth conditions, such as temperature, pH, and medium composition. This study aimed to evaluate the effect of different culture media on the production of bacteriocins and antimicrobial activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The strains were inoculated alone and in coculture in four different media: BHI broth, MRS broth, meat broth, and reconstituted skim milk (RSM) 10% (w/v). The culture media were then incubated at 37 °C for 96 h, and count analysis, pH measurement, and bacteriocin production were performed at 0, 24, 48, 72 and 96 h. L. monocytogenes was inhibited to nondetectable levels in coculture with P. pentosaceus ST65ACC in MRS broth within 96 h, consistent with the high production of bacteriocin throughout the analysis period (3,200–12,800 AU/mL). However, lower inhibitory activities of P. pentosaceus ST65ACC on L. monocytogenes Scott A were recorded in BHI, RSM, and meat broth, with low or no production of bacteriocins at the analyzed times. The composition of these culture media may have repressed the production and activity of bacteriocins and, consequently, the antagonist activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The results showed that the antimicrobial activity was more effective in MRS broth, presenting greater production of bacteriocins and less variability when compared to the other media analyzed.

Among the milk contaminating microorganisms, those which are able to form heat-resistant spores are concerning, especially for dairy companies that use ultra-high temperature (UHT) technology. These spores, throughout storage, can germinate and produce hydrolytic enzymes that compromise the quality of the final product. This study evaluated 184 UHT milk samples from different batches collected from seven Brazilian dairy companies with a possible microbial contamination problem. The bacteria were isolated, phenotypically characterized, clustered by REP-PCR, and identified through 16S rDNA sequencing. The presence of Bacillus sporothermodurans was verified using biochemical tests (Gram staining, catalase and oxidase test, glucose fermentation, esculin hydrolysis, nitrate reduction, and urease test). According to these tests, none of the isolates presented typical characteristics of B. sporothermodurans. In sequence, the isolates, that presented rod-shapes, were submitted to molecular analyses in order to determine the microbial biodiversity existing among them. The isolates obtained were grouped into 16 clusters, four of which were composed of only one individual. A phylogenetic tree was constructed using the sequences obtained from the 16S rDNA sequencing and some reference strains of species close to those found using BLAST search in the NCBI nucleotide database. Through this tree, it was possible to verify the division of the isolates into two large groups, the Bacillus subtilis and the Bacillus cereus groups. Furthermore, most isolates are phylogenetically closely related, which makes it even more difficult to identify them at the species level. In conclusion, it was possible to assess, in general, the groups of sporulated contaminants in Brazilian UHT milk produced in the regions evaluated. In addition, it was also possible to determine the biodiversity of spore-forming bacteria found in UHT milk samples, thus opening up a range of possible research topics regarding the effects of the presence of these microorganisms on milk quality.

Few studies have investigated the diversity of spoilage fungi from the dairy production chain in Brazil, despite their importance as spoilage microorganisms. In the present study, 109 filamentous fungi were isolated from various spoiled dairy products and dairy production environments. The isolates were identified through sequencing of the internal transcribed spacer (ITS) region. In spoiled products, Penicillium and Cladosporium were the most frequent genera of filamentous fungi and were also present in the dairy environment, indicating that they may represent a primary source of contamination. For dairy production environments, the most frequent genera were Cladosporium, Penicillium, Aspergillus, and Nigrospora. Four species (Hypoxylon griseobrunneum, Rhinocladiella similis, Coniochaeta rosae, and Paecilomyces maximus) were identified for the first time in dairy products or in dairy production environment. Phytopathogenic genera were also detected, such as Montagnula, Clonostachys, and Riopa. One species isolated from the dairy production environment is classified as the pathogenic fungi, R. similis. Regarding the phylogeny, 14 different families were observed and most of the fungi belong to the Ascomycota phylum. The understanding of fungal biodiversity in dairy products and environment can support the development of conservation strategies to control food spoilage. This includes the suitable use of preservatives in dairy products, as well as the application of specific cleaning and sanitizing protocols designed for a specific group of target microorganisms.

Processed cheese is a dairy product with multiple end-use applications, where emulsifying salts play a fundamental role in physicochemical changes during production. Moreover, some of these salts may be a strategy to control spoilage and pathogenic microorganisms, contributing to safety and shelf life extension. This study aimed to evaluate the in vitro inhibitory activity of two emulsifying salts (ESSP = short polyP and BSLP = long polyP) against Bacillus thuringiensis CFBP 3476 and Clostridium perfringens ATCC 13124, and to compare the in situ effects of two emulsifying salts treatments (T1 = 1.5% ESSP and T2 = 1.0% ESSP + 0.5% BSLP) in processed cheeses obtained by two different methods (laboratory- and pilot-scales), during 45-day storage at 6 °C. C. perfringens ATCC 13124 growth was not affected in vitro or in situ (p > 0.05), but both of the treatments reduced B. thuringiensis CFBP 4376 counts in the tested condition. Counts of the treatments with B. thuringiensis CFBP 3476 presented a higher and faster reduction in cheeses produced by the laboratory-scale method (1.6 log cfu/g) when compared to the pilot-scale method (1.8 log cfu/g) (p < 0.05). For the first time, the inhibitory effect of emulsifying salts in processed cheeses obtained by two different methods was confirmed, and changes promoted by laboratory-scale equipment influenced important interactions between the processed cheese matrix and emulsifying salts, resulting in B. thuringiensis CFBP 4376 growth reduction.

Hantavirus cardiopulmonary syndrome (HCPS) is an infectious disease caused by hantaviruses of the family Bunyaviridae, and is transmitted by aerosols of excreta of infected rodents. The aim of the present study was to determine antibody levels to hantavirus in the population that lives at frontier of Brazil and Argentina. Participated of the study 405 individuals living in the municipalities of Bandeirante, Santa Helena, Princesa and Tunapolis, state of Santa Catarina, Brazil. IgG antibodies to hantavirus were analyzed in sera by an ELISA that uses a recombinant N protein of Araraquara hantavirus as antigen. The results were also confirmed by immunofluorescent test. Eight individuals showed antibodies to hantavirus (1.97% positivity), with serum titers ranging from 100 to 800. Six seropositives were males, older than 30 years and farmers. Our results reinforce previous data on hantavirus circulation and human infections in the southern border of Brazil with Argentina. Síndrome Cardiopulmonar por Hantavírus (HCPS) é uma doença emergente, causada pelo gênero hantavírus membro da família Bunyaviridae, e são transmitidos aos humanos por aerossol de roedores infectados. O objetivo principal deste estudo foi determinar os níveis de anticorpos para hantavírus em uma população de residentes na fronteira do Brasil com a Argentina. Participaram deste estudo 405 indivíduos que moravam nos municípios de Bandeirante, Santa Helena, Princesa e Tunapólis, no estado de Santa Catarina, Brasil. Os anticorpos IgG para hantavírus foram analisados no soro por um ELISA que usa a nucleoproteína recombinante do vírus Araraquara como antígeno, posteriormente confirmados por imunofluorescência. Oito indivíduos apresentavam anticorpos para hantavírus (1.97% positivo), com titulo entre 100 a 800. Seis soropositivos foram homens, com idade superior a 30 anos e agricultores. Nossos resultados reforçam a circulação do hantavírus e infecção humana na fronteira do Brasil com a Argentina

Most Pseudomonas spp. are responsible for spoilage in refrigerated foods such as alteration in flavor, texture and appearance. Samples of Minas Frescal cheese with blue discoloration were analysed and contained a high Pseudomonas concentration (7.72 ± 0.36 log CFU/g). Out of the 26 Pseudomonas isolates that were analyzed in our study, 19 demonstrated the capability of producing a diffusible dark pigment. Thus, a pigment-producing isolate (C020) was selected by rep-PCR fingerprinting and subsequently subjected to whole-genome sequencing. The draft genome assembled comprises 42 contigs totaling 6,366,75 bp with an average G + C content of 59.97%, and the species prediction performed by TYGS server, based on the draft genome sequence, identified the C020 as Pseudomonas carnis . In order to investigate the phylogenetic relationships of this isolate with strains already identified of this species, we performed an analysis based on whole-genomic sequences. First, an analysis of all P. carnis genomes deposited in GenBank to date shows that 11% (4/37) are misidentified, and belong to the Pseudomonas paracarnis species. A comparative analysis based on phylogenomic analysis has showed that there is no evolutionary relationship between P. carnis strains carrying second copies of trp genes related to blue discoloration ( trpABCDF ). This finding reinforces the assertion that these genes are contained in a mobile genetic element. However, it is worth noting that all strains carrying these secondary gene copies have exclusively been isolated from food sources. This observation provides valuable insights into the potential origins and dispersion dynamics of this genetic trait within the species.