Reemergency of Salmonellosis in hog farms: outbreak and bacteriological characterization

Authors: MENEGUZZI, MARIANA - Universidade Federal De Santa Catarina (UFSC); PISSETTI, CAROLINE - Universidade Federal Do Rio Grande Do Norte; REBELATTO, RAQUEL - Embrapa; Trachsel, Julian; SATOMI KUCHIISHIE, SUZANA - University Of Santo Domingo; REISF, ADRIENNY - Instituto De Pesquisa E Reabilitacao De Animais Marinhos; GUEDESG, ROBERTO - Federal University Of Minas Gerais; LEÃOH, JOICE - Western Paraná State University; REICHENA, CAROLINE - Universidade Federal De Santa Catarina (UFSC); DEON, JALUSA - Embrapa

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2021
Publication Date: 4/28/2021
Citation: Meneguzzi, M., Pissetti, C., Rebelatto, R., Trachsel, J.M., Satomi Kuchiishie, S., Reisf, A.T., Guedesg, R.M., Leãoh, J.A., Reichena, C., Deon, J.K. 2021. Reemergency of Salmonellosis in hog farms: outbreak and bacteriological characterization. Microorganisms. 9(5). Article 947. https://doi.org/10.3390/microorganisms9050947.

Interpretive Summary: Salmonella is a type of bacteria that can reside in the intestines of animals, and sometimes, can make the animal sick. When humans eat food products contaminated with Salmonella, that person could get sick too, and is referred to as foodborne illness. To help make sure the food we eat is safe, it is important to know if, and what kinds of, Salmonella are infecting livestock. Salmonella infections in swine have increased in Brazil over the past decade. Many different Salmonella outbreaks across Brazil were investigated to identify the strains, or types, of Salmonella responsible for the infections. Many different strains of Salmonella were identified, some that could make pigs very sick, and many that were resistant to multiple antibiotics. The strains of Salmonella in pigs may contaminate pork products and make humans sick, and antibiotic resistance in Salmonella may limit treatment but also be a source of antibiotic resistance to other bacteria. Overall, the results suggest strains of Salmonella that infect swine are common throughout Brazil, Given the global food market, it’s important to understand foodborne pathogens in the US and other countries, and global strategies to limit Salmonella in food animals may be needed to maintain a safe and secure food supply.

Technical Abstract: Clinical salmonellosis has been increasing significantly in Brazil in recent years. A total of 130 outbreaks distributed among ten swine-producing states were investigated. One representative Salmonella isolate from each outbreak was characterized through serotyping, antimicrobial resistance profiles, PFGE, and WGS. From 130 outbreaks: 50 were enteric, 48 were septicemic, 17 cases were characterized as hepato-biliary invasive and 13 as nodal. The most prevalent serovars were a monophasic variant of S. Typhimurium (55/130), Choleraesuis (46/130), and Typhimurium (14/130). Most of the strains (86.92%) demonstrated a high rate of multi-drug resistance. The identification of a major Choleraesuis clonal group in several Brazilian states sharing the same resistance genes suggested that these strains were closely related. Six strains from this clonal group were sequenced, revealing the same ST-145 and 11 to 47 different SNPs. The detected plasmid type showed multiple marker genes as RepA_1_pKPC-CAV1321, the first to be reported in Salmonella. All AMR genes detected in the genomes were likely present on plasmids, and their phenotype was related to genotypic resistance genes. These findings reveal that salmonellosis is endemic in the most important pig-producing states in Brazil, emphasizing the need to make data available to aid in reducing its occurrence.