Frequency, serotyping and antimicrobial resistance pattern of Salmonella from feces and lymph nodes of pigs

ABSTRACT: Salmonellosis is a foodborne disease caused by bacteria of the genus Salmonella, being pigs and pork-products potentially important for its occurrence. In recent decades, some serovars of Salmonella have shown increase of resistance to conventional antimicrobials used in human and animal therapy, with serious risks for public health. The aim of this study was to evaluate feces (n=50), mediastinal (n=50), mesenteric (n=50) and mandibular (n=50) lymph nodes obtained from slaughter houses for Salmonella spp. Positive samples were serotyped and subjected to an in vitro antimicrobial susceptibility test, including the extended-spectrum beta-lactamase (ESBL) production. Salmonella species were identified in 10% (20/200) of total samples. From these, 20% (10/50) were identified in the submandibular lymph nodes, 18% (9/50) in the mesenteric lymph nodes, 2% (1/50) in feces and 0% (0/50) in the mediastinal lymph nodes. The serotypes found were Salonella Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg and S. Derby with 5% (5% each). All strains showed resistance to at least one antimicrobial; 90% were resistant to four or more antimicrobials, and 15% were multidrug-resistant. Resistance to ciprofloxacin, tetracycline and nalidixic acid was particularly prevalent amongst the tested serovars. Here, we highlighted the impact of pigs in the epidemiological chain of salmonellosis in domestic animals and humans, as well as the high antimicrobial resistance rates of Salmonella strains, reinforcing the necessity for responsible use of antimicrobials for animals as an emergent One Health issue, and to keep these drugs for human therapy approaches

Inhibitory effects of piperine and black pepper essential oil on multispecies biofilm formation by Listeria monocytogenes, Salmonella Typhimurium, and Pseudomonas aeruginosa

This study aimed to evaluate the antimicrobial and antibiofilm activities of black pepper essential oil (BPEO) and piperine and the effect of piperine on gene expression in a multispecies biofilm composed of Listeria monocytogenes, Salmonella Typhimurium, and Pseudomonas aeruginosa on a polypropylene surface. The minimal inhibitory concentrations of BPEO and piperine were 100 and 25 mg/mL, respectively, against this consortium of microorganisms. Sessile cell counts were 5.357.35 log CFU/cm2 and varied over time. The total population eradicated in the biofilm ranged from 78.9% (5.88 log CFU/cm2) to 99.8% (4.16 log CFU/cm2). Evaluation of biofilm-related gene expression showed upregulation of the L. monocytogenes genes agrC (24 and 72 h), agrD (72 h), and prfA (72 h) and downregulation of all evaluated S. Typhimurium and P. aeruginosa genes (24 and 72 h) in the untreated control biofilm. The addition of piperine resulted in upregulation of the L. monocytogenes genes agrB (24 and 72 h), agrC (72 h), agrD (24 and 72 h), and prfA (24 h); the S. Typhimurium genes agfA (24 and 72 h), adrA (24 and 72 h), and csgD (72 h); and all evaluated P. aeruginosa genes (24 and 72 h). Piperine more effectively controlled the multispecies biofilm.The authors thank the National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq, Brasília, DF, Brazil), the Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES, Brasília, DF, Brazil – Code 001), and the Federal University of Paraná (Universidade Federal do Paraná – UFPR; nº 02/2020 – RESEARCH/PRPPG/UFPR – Araucária Foundation).info:eu-repo/semantics/publishedVersio

The Omicron Lineages BA.1 and BA.2 (<i>Betacoronavirus</i> SARS-CoV-2) Have Repeatedly Entered Brazil through a Single Dispersal Hub

Brazil currently ranks second in absolute deaths by COVID-19, even though most of its population has completed the vaccination protocol. With the introduction of Omicron in late 2021, the number of COVID-19 cases soared once again in the country. We investigated in this work how lineages BA.1 and BA.2 entered and spread in the country by sequencing 2173 new SARS-CoV-2 genomes collected between October 2021 and April 2022 and analyzing them in addition to more than 18,000 publicly available sequences with phylodynamic methods. We registered that Omicron was present in Brazil as early as 16 November 2021 and by January 2022 was already more than 99% of samples. More importantly, we detected that Omicron has been mostly imported through the state of São Paulo, which in turn dispersed the lineages to other states and regions of Brazil. This knowledge can be used to implement more efficient non-pharmaceutical interventions against the introduction of new SARS-CoV variants focused on surveillance of airports and ground transportation