Molecular Characterization and Survive Abilities of Salmonella Heidelberg Strains of Poultry Origin in Brazil

Virulence, multiple drug resistance, and biofilm-formation in Salmonella species isolated from layer, broiler, and dual-purpose indigenous chickens

Globally, the significant risk to food safety and public health posed by antimicrobial-resistant foodborne Salmonella pathogens is driven by the utilization of in-feed antibiotics, with variations in usage across poultry production systems. The current study investigated the occurrence of virulence, antimicrobial resistant profiles, and biofilm-forming potentials of Salmonella isolates sourced from different chicken types. A total of 75 cloacal faecal samples were collected using sterile swabs from layer, broiler, and indigenous chickens across 15 poultry farms (five farms per chicken type). The samples were analysed for the presence of Salmonella spp. using species-specific PCR analysis. Out of the 150 presumptive isolates, a large proportion (82; 55%) were confirmed as Salmonella species, comprising the serovars S. typhimurium (49%) and S. enteritidis (30%) while 21% were uncategorised. Based on phenotypic antibiotic susceptibility test, the Salmonella isolates were most often resistant to erythromycin (62%), tetracycline (59%), and trimethoprim (32%). The dominant multiple antibiotic resistance phenotypes were SXT-W-TE (16%), E-W-TE (10%), AML-E-TE (10%), E-SXT-W-TE (13%), and AMP-AML-E-SXT-W-TE (10%). Genotypic assessment of antibiotic resistance genes revealed that isolates harboured the ant (52%), tet (A) (46%), sui1 (13%), sui2 (14%), and tet (B) (9%) determinants. Major virulence genes comprising the invasion gene spiC, the SPI-3 encoded protein (misL) that is associated with the establishment of chronic infections and host specificity as well as the SPI-4 encoded orfL that facilitates adhesion, autotransportation and colonisation were detected in 26%, 16%, and 14% of the isolates respectively. There was no significant difference on the proportion of Salmonella species and the occurrence of virulence and antimicrobial resistance determinants among Salmonella isolates obtained from different chicken types. In addition, neither the chicken type nor incubation temperature influenced the potential of the Salmonella isolates to form biofilms, although a large proportion (62%) exhibited weak to strong biofilm-forming potentials. Moderate to high proportions of antimicrobial resistant pathogenic Salmonella serovars were detected in the study but these did not vary with poultry production systems.

Genetic and in-silico approaches for investigating the mechanisms of ciprofloxacin resistance in Salmonella typhi: Mutations, extrusion, and antimicrobial resistance

Salmonella enterica serovar Typhi spreads typhoid infection in humans through the consumption of contaminated food and water. Poor sanitation plays a pivotal role in its dissemination. Over time, the bacterium has acquired resistance to many promising antibiotics, posing a growing global health concern and hindering the achievement of sustainable development goals. This study aims to elucidate the molecular complexity of fluoroquinolone resistance, a first-line treatment for typhoid infection. To achieve this aim, 80 clinical isolates were collected from various diagnostic laboratories. These isolates were confirmed based on morphological characteristics and biochemical tests. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were identified using the Kirby-Bauer disc diffusion method. The mechanism of ciprofloxacin resistance was investigated by sequencing the quinolone resistance-determining region (QRDR) genes and identifying the presence of the qnrS1 gene. As a result of this study, 60 % of isolates showed resistance to ciprofloxacin. At the same time, the qnrS1 gene was present in all the selected strains while mutation analysis identified significant mutation in QRDR of DNA gyrase subunit A (gyrA) and Topoisomerase IV (parC) gene. The combinatorial effect was further investigated by downloading 286 draft genomes. The Mutation analysis reveals significant mutations at gyrA S83F, gyrA D87N, gyrA S83Y, gyrB S464F, parC S80I, and parE L416F. Additionally, docking analysis indicates reduced binding affinity and altered solvent accessibility, which show the structural changes at mutation sites. This study provides crucial insights that mutation reduces the binding affinity while qnrS1 acts as a transport channel to extrude the ciprofloxacin. In the future, further validation through experimental mutagenesis is recommended, for targeted therapeutic interventions against the mounting threat of antibiotic-resistant S. Typhi.

Emerging Approaches for Mitigating Biofilm-Formation-Associated Infections in Farm, Wild, and Companion Animals

The importance of addressing the problem of biofilms in farm, wild, and companion animals lies in their pervasive impact on animal health and welfare. Biofilms, as resilient communities of microorganisms, pose a persistent challenge in causing infections and complicating treatment strategies. Recognizing and understanding the importance of mitigating biofilm formation is critical to ensuring the welfare of animals in a variety of settings, from farms to the wild and companion animals. Effectively addressing this issue not only improves the overall health of individual animals, but also contributes to the broader goals of sustainable agriculture, wildlife conservation, and responsible pet ownership. This review examines the current understanding of biofilm formation in animal diseases and elucidates the complex processes involved. Recognizing the limitations of traditional antibiotic treatments, mechanisms of resistance associated with biofilms are explored. The focus is on alternative therapeutic strategies to control biofilm, with illuminating case studies providing valuable context and practical insights. In conclusion, the review highlights the importance of exploring emerging approaches to mitigate biofilm formation in animals. It consolidates existing knowledge, highlights gaps in understanding, and encourages further research to address this critical facet of animal health. The comprehensive perspective provided by this review serves as a foundation for future investigations and interventions to improve the management of biofilm-associated infections in diverse animal populations.

Antibacterial efficiency of apple vinegar marination on beef-borne Salmonella

Background

Salmonella-related foodborne illnesses are a significant public health concern. Naturally, antibacterial food components have been shown to limit microbial growth proliferation with various degrees of efficacy.

Aims

To examine the occurrence, microbial load, and effect of apple vinegar on Salmonella serovars in beef and beef products.

Methods

150 beef and beef products were collected between March and May 2022. Total viable count (TVC), Enterobacteriaceae count (ENT), isolation and identification of Salmonella, and their virulence factors detection by multiplex PCR were determined, and an experimental study of the effect of natural apple vinegar marination on Salmonella spp.

Results

TVC was higher in meatballs (3.32 × 106 ± 1.07 × 106) while beef burgers (4.22 × 103 ± 0.71 × 103) had the highest ENT. Concerning the prevalence of Salmonella spp., meatball (46.7%) and beef burger (25.3%) samples were the highest contamination rate. The common serovars detected were Salmonella typhimurium (6%), Salmonella enteritidis (6%), and Salmonella infantis (4%). Based on the results of PCR, 12, 11, and 11 out of 18 samples of Salmonella isolates possess hila, stn, and invA genes. By immersing the inoculated steak meat in apple vinegar at different concentrations (50%, 70%, and 100%), the initial populations of the Salmonella strains after 12 hours were reduced to 0.38 × 102 ± 0.05 × 102 log CFU/ml; however, after 48 hours become the most reduction (0.31 × 102 ± 0.07 × 102 log CFU/ml) at a concentration of 100% apple vinegar. An enhancement in the sensory attributes was noted across all concentrations.

Conclusion

The consumed beef and beef products are contaminated with pathogenic bacteria such as Salmonella spp. Marinades made using apple vinegar concentrations of 50%, 75%, and 100% effectively minimized the prevalence of artificially inoculated Salmonella and extended the shelf life of preserved refrigerated beef products to 48 hours.

Genomic and proteomic analysis of Salmonella Enteritidis isolated from a patient with foodborne diarrhea

Salmonella is a major cause of foodborne diseases and clinical infections worldwide. This study aimed to investigate the drug resistance, genomic characteristics, and protein expression of foodborne Salmonella in Shanxi Province. We isolated a strain of Salmonella Enteritidis from patient feces and designated it 31A. The drug resistance of 31A against 14 antibiotics was determined using an antimicrobial susceptibility test. Whole-genome sequencing and quantitative proteomic analysis were performed on the 31A strain. Functional annotation of drug resistance genes/proteins and virulence genes/proteins was conducted using various databases, such as VFDB, ARDB, CAZY, COG, KOG, CARD, GO, and KEGG. The focus of this study was understanding the mechanisms related to food poisoning, and the genetic evolution of 31A was analyzed through comparative genomics. The 31A strain belonged to ST11 Salmonella Enteritidis and showed resistance to β-lactam and quinolone antibiotics. The genome of 31A had 70 drug resistance genes, 321 virulence genes, 12 SPIs, and 3 plasmid replicons. Functional annotation of these drug resistance and virulence genes revealed that drug resistance genes were mainly involved in defense mechanisms to confer resistance to antibiotics, while virulence genes were mainly associated with cellular motility. There were extensive interactions among the virulence genes, which included SPI-1, SPI-2, flagella, fimbriae, capsules and so on. The 31A strain had a close relationship with ASM2413794v1 and ASM130523v1, which were also ST11 Salmonella Enteritidis strains from Asia and originated from clinical patients, animals, and food. These results suggested minimal genomic differences among strains from different sources and the potential for interhost transmission. Differential analysis of the virulence and drug resistance-related proteins revealed their involvement in pathways related to human diseases, indicating that these proteins mediated bacterial invasion and infection. The integration of genomic and proteomic information led to the discovery that Salmonella can survive in a strong acid environment through various acid resistance mechanisms after entering the intestine with food and then invade intestinal epithelial cells to exert its effects. In this study, we comprehensively analyzed the drug resistance and virulence characteristics of Salmonella Enteritidis 31A using a combination of genomic and proteomic approaches, focusing on the pathogenic mechanism of Salmonella Enteritidis in food poisoning. We found significant fluctuations in various virulence factors during the survival, invasion, and infection of Salmonella Enteritidis, which collectively contributed to its pathogenicity. These results provide important information for the source tracing, prevention, and treatment of clinical infections caused by Salmonella Enteritidis.

The Resistance and Virulence Characteristics of Salmonella Enteritidis Strain Isolated from Patients with Food Poisoning Based on the Whole-Genome Sequencing and Quantitative Proteomic Analysis

Objective

This paper explores the drug resistance, genome and proteome expression characteristics of Salmonella from a food poisoning event.

Methods

A multidrug-resistant Salmonella Enteritidis strain, labeled as 27A, was isolated and identified from a food poisoning patient. Antimicrobial susceptibility testing determined the resistance of 27A strain to 14 antibiotics. Then, WGS analysis and comparative genomics analysis were performed on 27A, and the functional annotation of resistance genes, virulence genes were performed based on VFDB, ARDB, COG, CARD, GO, KEGG, and CAZY databases. Meanwhile, based on iTRAQ technology, quantitative proteomic analysis was conducted on 27A to analyze the functions and interactions of differentially expressed proteins related to bacterial resistance and pathogenicity.

Results

Strain 27A belonged to ST11 S. Enteritidis and was resistant to levofloxacin, ciprofloxacin, ampicillin, piperacillin, and ampicillin/sulbactam. There were 33 drug resistance genes, 384 virulence genes and 2 plasmid replicon, IncFIB(S) and IncFII(S), annotated by WGS. Proteomic analysis revealed significant changes in virulence and drug proteins, which were mainly involved in bacterial pathogenicity and metabolic processes. PPI prediction showed the relationship between virulence proteins and T3SS proteins, and PagN cooperated with proteins related to T3SS to jointly mediate the invasion of 27A strain on the human body. Phylogenetic analysis indicated that S. Enteritidis has potential transmission in humans, food, and animals.

Conclusion

This study comprehensively analyzed the drug resistance and virulence phenotypes of S. Enteritidis 27A using genomic and proteomic approaches. These helps reveal the drug resistance and virulence mechanisms of S. Enteritidis, and provides important information for the source tracing and the prevention of related diseases, which lays a foundation for research on food safety, public health monitoring, and the drug resistance and pathogenicity of S. Enteritidis.

Interference with Bacterial Conjugation and Natural Alternatives to Antibiotics: Bridging a Gap

Horizontal gene transfer (HGT) in food matrices has been investigated under conditions that favor gene exchange. However, the major challenge lies in determining the specific conditions pertaining to the adapted microbial pairs associated with the food matrix. HGT is primarily responsible for enhancing the microbial repertoire for the evolution and spread of antimicrobial resistance and is a major target for controlling pathogens of public health concern in food ecosystems. In this study, we investigated Salmonella Heidelberg (SH) and Escherichia coli (EC) regarding gene exchange under conditions mimicking the industrial environment, with the coproducts whey (SL) and chicken juice (CJ). The S. Heidelberg strain was characterized by antibiotic susceptibility standards and PCR to detect the bla_TEM gene. A concentration of 0.39 mg/mL was determined to evaluate the anti-conjugation activity of nanostructured lipid nanocarriers (NLCs) of essential oils to mitigate β-lactam resistance gene transfer. The results showed that the addition of these coproducts promoted an increase of more than 3.5 (whey) and 2.5 (chicken juice) orders of magnitude in the conjugation process (p < 0.01), and NLCs of sage essential oil significantly reduced the conjugation frequency (CF) by 74.90, 90.6, and 124.4 times when compared to the transfers in the absence of coproducts and the presence of SL and CJ, respectively. For NLCs from olibanum essential oil, the decrease was 4.46-fold for conjugations without inhibitors and 3.12- and 11.3-fold in the presence of SL and CJ. NLCs associated with sage and olibanum essential oils effectively control the transfer of antibiotic resistance genes and are a promising alternative for use at industrial levels.

Phenotypic and genotypic characterization of antibiotic resistance of Salmonella Heidelberg in the south of Brazil

Salmonella is the main human pathogen present in the poultry chain. Salmonella Heidelberg is one of the most important serovars for public health since it has been frequently isolated in broiler chickens from different countries and may present multidrug resistance (MDR). This study was carried out with 130 S. Heidelberg isolates collected from pre-slaughter broiler farms in 2019 and 2020 in 18 cities from three Brazilian states to study relevant aspects regarding their genotypic and phenotypic resistance. The isolates were tested and identified using somatic and flagellar antiserum (0:4, H:2, and H:r), and an antimicrobial susceptibility test (AST) was performed against 11 antibiotics for veterinary use. The strains were typed by Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR, and representatives of the main clusters of the identified profiles were sequenced by Whole Genome Sequencing (WGS). AST results showed that all isolates were resistant to sulfonamide, 54 % (70/130) were resistant to amoxicillin, and only one was sensitive to tetracycline. Twelve isolates (15.4 %) were MDR. The dendrogram obtained from the ERIC-PCR showed that the strains were grouped into 27 clusters with similarity above 90 %, with some isolates showing 100 % similarity but with different phenotypic profiles of antimicrobial resistance. Identical strains collected on the same farm on other dates were identified, indicating that they were residents. WGS identified 66 antibiotic-resistance genes. The sul2 (present in all sequenced samples) and tet(A) genes were highlighted and validated in the experimental analysis. The fosA7 gene was also identified in all sequenced samples, but resistance was not observed in the phenotypic test, possibly due to the heteroresistance of the S. Heidelberg strains evaluated. Considering that chicken meat is one of the most consumed meats in the world, the data obtained in the present study can corroborate the mapping of the origin and trends of antimicrobial resistance.

Genomic analyses of drug-resistant Salmonella enterica serovar Heidelberg strains isolated from meat and related sources between 2013 and 2017 in the south region of Brazil

Salmonella enterica serovar Heidelberg (S. Heidelberg) is a zoonotic, ubiquitous, and worldwide-distributed pathogen, responsible for gastroenteritis in humans caused by the consumption of contaminated food. In this study, 11 S. Heidelberg strains isolated from chicken and bovine meat, drag swab, and animal feed between 2013 and 2017 in states of the southern region of Brazil were characterized by whole-genome sequencing (WGS) analyses. Antimicrobial resistance against 18 antimicrobials was determined by disk-diffusion and ciprofloxacin's minimum inhibitory concentration by Etest®. The search for resistance and virulence genes, plasmids, Salmonella Pathogenicity Islands (SPIs) plus multi-locus sequence typing (MLST), and single-nucleotide polymorphisms (SNPs) analyses was conducted using WGS data. All strains harbored resistance genes fosA7, aac(6')-Iaa, sul2, tet(A), bla_CMY-2, mdsA, and mdsB_, and point mutations in gyrA and parC. All strains showed a phenotypic multidrug-resistant profile, with resistant or intermediate resistant profiles against 14 antimicrobials tested. Plasmids ColpVC, IncC, IncX1, and IncI1-I(Alpha) were detected. Virulence genes related to adherence, macrophage induction, magnesium uptake, regulation, and type III secretion systems plus 10 SPIs were detected. All strains were assigned to ST15 and belonged to two SNP clusters showing high similarity to isolates from the United Kingdom, Chile, Germany, the Netherlands, China, South Africa, and South Korea. In conclusion, the presence of multidrug-resistant S. Heidelberg strains in Brazil showing a global genomic relationship may alert for the necessity of stronger surveillance measures by food safety and public health authorities to limit its spread to humans and animals through foods.

Effect of diets containing commercial bioactive compounds on Salmonella Heidelberg infection in broiler chicks

Salmonella Heidelberg (SH) is responsible for economic losses in poultry farming and food infections in humans and is a serious public health problem. Recently, there has been an increase in the frequency of isolation of this serotype in batches of broilers raised in Brazil. It is necessary to find new ways to help control this pathogen. The present study aimed to evaluate the effect of diets containing the compound Original XPC, which is a prebiotic-like fermented compound (PFC), and/or Sangrovit, which is a sanguinarine-based phytobiotic (SAN), on SH infection in broiler chicks. For this purpose, SH colonization in the cecum and its invasion into the spleen and liver were evaluated, as were the histopathological changes caused in these organs. The lowest cecal SH counts were observed in birds that ingested SAN, followed by those fed PFC (P < 0.05), with no added effect when the two bioproducts were used together (SAN + PFC). The mean SH and liver spleen counts did not differ between groups (P > 0.05). In general, birds from all groups challenged with SH showed similar macroscopic changes, such as hemorrhagic areas, hepatomegaly, and splenomegaly, such changes being more intense in the infected control group. The microscopic changes observed in the liver included hepatocyte congestion, heterophil infiltration in the sinusoid capillaries, areas of necrosis, and mononuclear inflammation. In the cecum, heterophilic infiltrate and thickening of the lamina propria were observed. In the ileum, the most common changes were congestion and thickening of the lamina propria and atrophy of the villi and crypts. The microscopic changes were less intense in the supplemented birds than the infected control group, and those supplemented with SAN developed the least changes. As ideal conditions for histomorphometric parameters of the ileum, the villus:crypt ratio in birds should be high, the villi should be long, and the crypts should be shallow. In the present study, higher mean heights and villus areas were observed in uninfected control and SAN group birds, and the crypt depth was lower in birds in the negative control group. The lowest villus:crypt ratio was observed in the birds of the infected control group. Although additional studies are needed, the preliminary results of the current investigation indicated that the addition of bioproducts, especially SAN, to the diet of birds helped to control SH infection, reducing its count in the cecum and improving overall and intestinal health.

Salmonella Heidelberg side-step gene loss of respiratory requirements in chicken infection model

Among the important recent observations involving anaerobic respiration was that an electron acceptor produced as a result of an inflammatory response to Salmonella Typhimurium generates a growth advantage over the competing microbiota in the lumen. In this regard, anaerobically, salmonellae can oxidize thiosulphate (S₂O₃^2-) converting it into tetrathionate (S₄O₆^2-), the process by which it is encoded by ttr gene cluster (ttrSRttrBCA). Another important pathway under aerobic or anaerobic conditions is the 1,2-propanediol-utilization mediated by the pdu gene cluster that promotes Salmonella expansion during colitis. Therefore, we sought to compare in this study, whether Salmonella Heidelberg strains lacking the ttrA, ttrApduA, and ttrACBSR genes experience a disadvantage during cecal colonization in broiler chicks. In contrast to expectations, we found that the gene loss in S. Heidelberg potentially confers an increase in fitness in the chicken infection model. These data argue that S. Heidelberg may trigger an alternative pathway involving the use of an alternative electron acceptor, conferring a growth advantage for S. Heidelberg in chicks.

Emergence, Dissemination and Antimicrobial Resistance of the Main Poultry-Associated Salmonella Serovars in Brazil

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.

Essential Oil-Based Nanoparticles as Antimicrobial Agents in the Food Industry

The use of essential oils (EO) loaded with nanoparticles is the most promising alternative to increase food quality and safety. Interesting works describe the antimicrobial properties of EO for pathogen control in natural and processed foods for human health and animal production, also contributing to sustainability. Their association with different nanosystems allows novel developments in the micronutrition, health promotion, and pathogen control fields, preventing the aggravation of bacterial microevolution and combating antibiotic resistance. Benefits to the environment are also provided, as they are biodegradable and biocompatible. However, such compounds have some physicochemical properties that prevent commercial use. This review focuses on recent developments in antimicrobial EO-based nanoparticles and their application in different food matrices.

A Ternary Copper (II) Complex with 4-Fluorophenoxyacetic Acid Hydrazide in Combination with Antibiotics Exhibits Positive Synergistic Effect against Salmonella Typhimurium

Salmonella spp. continues to figure prominently in world epidemiological registries as one of the leading causes of bacterial foodborne disease. We characterised 43 Brazilian lineages of Salmonella Typhimurium (ST) strains, characterized drug resistance patterns, tested copper (II) complex as control options, and proposed effective antimicrobial measures. The minimum inhibitory concentration was evaluated for seven antimicrobials, isolated and combined with the copper (II) complex [Cu(4-FH)(phen)(ClO4)2] (4-FH = 4-fluorophenoxyacetic acid hydrazide and phen = 1,10-phenanthroline), known as DRI-12, in planktonic and sessile ST. In parallel, 42 resistance genes were screened (PCR/microarray). All strains were multidrug resistant (MDR). Resistance to carbapenems and polymyxins (86 and 88%, respectively) have drawn attention to the emergence of the problem in Brazil, and resistance is observed also to CIP and CFT (42 and 67%, respectively), the drugs of choice in treatment. Resistance to beta-lactams was associated with the genes blaTEM/blaCTX-M in 39% of the strains. Lower concentrations of DRI-12 (62.7 mg/L, or 100 μM) controlled planktonic and sessile ST in relation to AMP/SUL/TET and AMP/SUL/TET/COL, respectively. The synergistic effect provided by DRI-12 was significant for COL/CFT and COL/AMP in planktonic and sessile ST, respectively, and represents promising alternatives for the control of MDR ST.

Molecular genotyping reveals inter-regional relatedness among antimicrobial resistant Salmonella Minnesota strains isolated from poultry farm and humans, Brazil

Genetic profiles of Salmonella Minnesota isolates were analyzed using pulsed-field gel electrophoresis (PFGE). In total, 13 isolates obtained from the broiler industry collected in the states of Minas Gerais (11) and São Paulo (2), as well as five recovered from cases of foodborne infections in humans in the states of Minas Gerais (2), Santa Catarina (1), and Rio Grande do Sul (2), were submitted to PFGE. These 18 S. Minnesota isolates together with other 12 of poultry origin were also subjected to antimicrobial susceptibility testing. The PFGE analysis of 18 strains of S. Minnesota generated a dendrogram that grouped the isolates with 83-90% similarity into four main clusters. Among them, cluster "A" grouped the majority of isolates (13), including two of human origin that showed 90% similarity with a broiler isolate, both recovered in Minas Gerais. The S. Minnesota isolates showed resistance to tetracycline (80%), cefoxitin (80%), ceftazidime (46.7%), nalidixic acid (23.3%), ciprofloxacin (13.3%), and streptomycin (10%). No resistance to gentamicin, chloramphenicol, meropenem, nitrofurantoin, and sulfamethoxazole-trimethoprim was found. Moreover, 23.3% of the evaluated isolates presented multi-resistance profile, all from Minas Gerais. The results highlight the importance of further studies involving S. Minnesota, which is prevalent in the Brazilian broiler flocks and could provoke foodborne infection in humans.