Salmonella Serovars Isolated from Poultry Breeding Flocks under the Brazilian Official Control Programme Between 2016 and 2018

Abstract

The control of Salmonella in the poultry production chain combined with biosecurity measures is an important tool to maintain and guarantee the sanitary status of Brazilian flocks. The aim of this work was to compare official laboratory data on molecular typification of Salmonella isolates from poultry breeding flocks in different Brazilian states between 2016 and 2018 and identify the production category with the most positive flocks, in light of current legislation. Surveillance data of positive samples from the official Brazilian Salmonella Control Programme sent to Federal Agricultural Defence Laboratory of São Paulo (LFDA-SP) after molecular characterization were analysed. These data were subject to an exploratory study, undergoing a descriptive statistical analysis followed by the use of frequency and non-parametric hypothesis tests. Overall, 49 serovars were detected in poultry broilerbreeder and layer-breeder flocks. Salmonella ser. Heidelberg, Salmonella ser. Anatum, Salmonella ser. Newport, Salmonella ser. Schwarzengrund and Salmonella ser. Mbandaka were the five most common isolated serovars. The data shows that there is an opportunity to improve biosecurity measures in parent breeder flocks. A total of 16 serovars were identified in turkey-breeders. Salmonella ser. Anatum, Salmonella ser. Newport, Salmonella ser. Brandenburg, Salmonella ser. Litchfield, and Salmonella ser. Livingstone were the most common ones. The four official controlled serovars represented a small part of the isolated strains. These data demonstrate the importance of an official program in Brazil for Salmonella surveillance in breeder flocks combined with biosecurity measures.

Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections

“…Failure to adequately clean or dispose of their clothing, boots, and tools can also result in contamination [208]. Several farm safety guidelines can be implemented to decrease the risk of infection disseminating from personnel, which includes (1) the movement of the visitors should be strictly restricted [209]; (2) visitors and workers must be supplied with clean outer clothes and boots [210]; (3) regular organic matter removal and provide footbaths with disinfectants, especially during working inside the farm [211]; (4) caring of the animals should always start with the healthy and the young stock and move to the sick and adult stocks [212]; (5) workers must not use the same tools for handling both food and manures or at least must be disinfected between use; (6) tools must not be borrowed from neighboring farms; (7) access to vehicles must be limited, especially in the farm premise, and vehicles must be cleaned and disinfected before entering the farm [208,213,214].…”

“…The purpose of attenuation is to eliminate pathogen's infectivity but preserve their immunogenicity [414]. These vaccines can effectively stimulate humoral and secretory antibodies, as well as activate cytotoxic T-cells [415]; (2) Killed-whole-cell vaccines are the vaccines in which the pathogens are killed but maintain their epitope structures intact to preserve their immunogenicity, while simultaneously eliminating their capacity to replicate or cause disease [416]; (3) Toxoid vaccines are a type of vaccine in which a pathogen's toxin is purified and subjected to formalin treatment to deactivate its harmful effects but retains its immunogenicity against the associated pathogen [417]; (4) Subunit vaccines are a class of vaccines which contain fragments of the pathogen, such as polysaccharides, nucleic acids, or proteins like flagellin or synthetic peptides [418]; (5) Outer membrane vesicle (OMV) vaccines are made up of naturally discharged constituents of OMVs from the bacterial outer membrane, featuring vital antigenic elements capable of eliciting an immune response without triggering any illness [419]; (6) Protein-polysaccharide conjugate vaccines consist of bacterial polysaccharides which are bound to proteins that enable a desired immune response [420]. These vaccines induce polysaccharide-specific B-cell immunity, help prevent colonization, and block person-person transmission, thus generating herd immunity [421]; (7) Recombinant viral and bacterial vector vaccines employ non-pathogenic viruses or bacteria as vectors to deliver genetic information encoding the antigens of the pathogen into the host cells, which subsequently elicits the immune response [422]; (8) Nanovaccines are an innovative class of vaccines that employ nanoparticles (NPs) as carriers or adjuvants.…”

“…The transmission of Salmonella to a healthy host occurs through the consumption of contaminated food and water [3,4]. Salmonella has been causing a significant impact on health and economics worldwide [5]. The World Health Organization (WHO) describes Salmonella as one of the four most important causes of diarrhea worldwide [6].…”