Influence of lactic acid and acetic acid on Salmonella spp. growth and expression of acid tolerance-related genes

Food Research International
Raquel Cristina Konrad BurinLuís Augusto Nero

Abstract

Salmonella spp. is an important foodborne pathogen, often associated with meat products. This pathogen presents a complex tolerance mechanism in the presence of organic acids, which is regulated by a diversity of genes, including rpoS, nlpD and clpP. The present study aimed to measure the expression of such genes by Salmonella strains subjected to acid stress conditions, and associate these data with microbial growth. A culture collection composed of 79 strains of Salmonella spp. obtained from bovine and swine production chains was subjected to PFGE using XbaI, and 3 strains (serovars Derby, Typhimurium and Meleagridis) were selected for acid tolerance trials. The selected strains were inoculated in meat extract broth (MEB) added to lactic or acetic acids at a final pH of 4.0, 5.0 or 6.0, and incubated at 37°C for 6, 12, 24 and 48h. As controls, Salmonella strains were inoculated in MEB at pH7.0, and incubated in the same conditions. Bacterial populations were monitored by direct plating and gene expression using qPCR. Salmonella presented similar populations to controls and evident expression of rpoS at pH5.0 and 6.0. However, Salmonella populations were not detectable after 6h at pH4.0. The adaptability of Salmonella to pH5.0...Continue Reading

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.