Salmonella infects poultry, and it is also a human foodborne pathogen. This bacterial genus is classified into several serovars/lineages, some of them showing high antimicrobial resistance (AMR). The ease of Salmonella transmission in farms, slaughterhouses, and eggs industries has made controlling it a real challenge in the poultry-production chains. This review describes the emergence, dissemination, and AMR of the main Salmonella serovars and lineages detected in Brazilian poultry. It is reported that few serovars emerged and have been more widely disseminated in breeders, broilers, and layers in the last 70 years. Salmonella Gallinarum was the first to spread on the farms, remaining as a concerning poultry pathogen. Salmonella Typhimurium and Enteritidis were also largely detected in poultry and foods (eggs, chicken, turkey), being associated with several human foodborne outbreaks. Salmonella Heidelberg and Minnesota have been more widely spread in recent years, resulting in frequent chicken/turkey meat contamination. A few more serovars (Infantis, Newport, Hadar, Senftenberg, Schwarzengrund, and Mbandaka, among others) were also detected, but less frequently and usually in specific poultry-production regions. AMR has been identified in most isolates, highlighting multi-drug resistance in specific poultry lineages from the serovars Typhimurium, Heidelberg, and Minnesota. Epidemiological studies are necessary to trace and control this pathogen in Brazilian commercial poultry production chains.

Salmonella serotype Minnesota has been increasingly detected in Brazilian poultry farms and food products (chicken meat, eggs) in recent years. In addition, S. Minnesota isolates from poultry are generally resistant to several antibiotics and persistent in farm environments. The present study aimed to assess phylogenomic diversity of S. Minnesota isolates from the poultry production chain in Brazil. In total, 107 worldwide S. Minnesota whole genomes (including 12 from Brazil) were analyzed using a comparative approach. Phylogenetic analysis demonstrated two clades more related to poultry production in Brazil: S. Minnesota poultry lineages I and II (SM-PLI and SM-PLII). Phylodynamic analysis demonstrated that SM-PLI had a common ancestor in 1915, while SM–PLII originated circa 1971. SM-PLII encompassed a higher number of isolates and presented a recent increase in effective population size (mainly from 2009 to 2012). Plasmids IncA/C2 and ColRNA, antimicrobial resistance genes (aph(3′)-Ia, blaCMY-2, qnrB19, sul2, and tet(A)) and mainly a virulence genetic cluster (including the yersiniabactin operon) were detected in isolates from SM-PLI and/or SM-PLII. This study demonstrates the dissemination of two distinct S. Minnesota lineages with high resistance to antibiotics and important virulence genetic clusters in Brazilian poultry farms.

Colonial cheese is a culturally and economically important product from the south of Brazil. As most of its production is artisanal, the technology employed is mostly knowledge passed down from one generation to the next according to family tradition and may be produced with raw or pasteurized milk. It is noted for its spicy flavour and variable composition and is often classified as a medium to high-moisture cheese. This intrinsic feature increases the risk of microbial spoilage and food poisoning. One of the main bio-indicators of contamination in colonial cheese is coagulase positive Staphylococcus. The purpose of this study was thephenotypic identification of Staphylococcus species isolated from the products and surfaces in the main production stages of colonial cheese. Staphylococcus sp. isolates from the food and the production environment were obtained from two colonial cheese-production agro-industries in Rio Grande do Sul. Samples of fresh milk, curd, ripening and final colonial cheese were collected. In addition, surface sampling was performed on the coagulation tanks, production tables, molds, cheese ripening shelves and on the hands of the handlers. Staphylococcus sp. isolates in the cheese and the production environments tested in this study were identified by phenotypic techniques through biochemical and MALDI-TOF MS analyses. These isolates were subjected to gene expression analysis for enterotoxins A, B, C, D, and E. All isolates (72) were identified as Staphylococcus sp., and 43% of the total isolates tested were coagulase positive. Staphylococcus aureus was the predominant species in the raw milk and production tanks. Regarding coagulase negative staphylococci isolates, S. warneri and S. sciuri were most abundant. The sea and seb genes were detected in 4% of the Staphylococcus isolates. The results indicate eleven different species of Staphylococcus present in the colonial cheese production environments studied. The predominant presence of S. aureus in the different samples of milk, curd, ripened cheese, ready-to-eat cheese and hands of the handlers indicates that there are issues with the selection of milk-producing animals, pasteurization process and/or hygiene control of handlers. The sea and seb genes were detected in samples of raw milk and colonial cheese. No enterotoxin genes were detected in coagulase negative staphylococci. KEY WORDS: Enterotoxins; polymerase chain reaction; time-offlight mass spectrometry; coagulase negative staphylococci; phenotypic identification; genotypic analysis; colonial cheese.