Research Publications (Food Safety)

SUMMARY Salmonella infection in humans from poultry meat and eggs can lead to symptoms including diarrhea, fever, and vomiting. Salmonella can be inhibited by acidifiers, which alter the bacterial cell membrane by disrupting bacterial nutrient transport and energy metabolism. This study analyzes the effects of a commercial acidifier, containing formic, propionic, and acetic acids combined with cinnamaldehyde, on Salmonella infection in laying hens.

SUMMARY Salmonella and Campylobacter are the two pathogens commonly associated with raw poultry meat, as poultry products are frequent vehicles of these bacteria. The objective of the current research was to determine the optimal contact time for 6 antimicrobial treatments, including water, 0.003% chlorine, 0.07% peracetic acid (PAA), 0.1% PAA, 0.35% cetylpyridinium chloride (CPC), and 0.6% CPC.

SUMMARY Drinking water contaminated with Salmonella could serve as a source for cecal colonization of the pathogen in birds. In this study, we investigated the efficacy of a generally recognized as safe—status essential oil (lemongrass essential oil, LGEO) against multidrug-resistant Salmonella enterica serovar Heidelberg (S. Heidelberg) in poultry drinking water.

SUMMARY Feed hygienics are of ever increasing importance in providing safe feed to animals, and ultimately safe food for consumers. Salmonella has been identified as a major microbial hazard in animal feed that has been linked to illness in both animals and humans. Use of antibiotics has decreased in recent years due to policies and practices of poultry production, increasing opportunities for potential pathogens in feed to affect poultry and poultry products.

SUMMARY The ability of pre-enrichment media to buffer pH changes that occur during incubation is essential for recovery and detection of Salmonella from feed/ingredients. Depending on feed/ingredient type, the pH of the pre-enrichment media can decrease during incubation to a pH 4.0–5.0. Acidic conditions can: 1) injure Salmonella, 2) kill Salmonella, and/or 3) affect their biochemical pathways.

SUMMARY In a global context of increased antibiotic resistance, feed additives with enhanced antimicrobial properties are a useful and increasingly needed strategy. Organic acids (OA) and botanical molecules such as nature identical compounds (NIC) have been shown to be effective against bacterial infections based on their antimicrobial activity.

Vibrio cholerae, an important waterborne pathogen, is a rod-shaped bacterium that naturally exists in aquatic environments. When conditions are unfavorable for growth, the bacterium can undergo morphological and physiological changes to assume a coccoid morphology. This stage in its life cycle is referred to as viable but non-culturable (VBNC) because VBNC cells do not grow on conventional bacteriological culture media.

Vibrio harveyi can cause infections and diseases in a variety of marine vertebrates and invertebrates, which are harmful to the aquaculture industry. The LuxS quorum-sensing system regulates the expression of virulence factors in a wide variety of pathogenic bacteria. In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi.

Resistance to antibiotics is one of the most critical health problems in the world. Therefore, finding new treatment methods to be used as alternatives to antibiotics has become a priority for researchers. Similar to phages, certain products containing antimicrobial components, such as molasses, are widely used to eliminate resistant bacteria.

Hyaluronic acid is a high-molecular-weight polysaccharide that is widely distributed in animal tissues. Bacterial hyaluronidases degrade hyaluronic acid as secreted enzymes and have been shown to contribute to infection. Staphylococcus aureus UAMS-1 is a clinical isolate that codes for two hyaluronidases (hysA1 and hysA2). Previous research has shown the presence of a full-length HysA1 protein from the S. aureus UAMS-1 strain with no evidence of enzymatic activity.

Antimicrobial resistance is one of the most serious threats to medical science. Food supply is recognized as a potential source of resistant bacteria, leading to the development of surveillance programs targeting primarily poultry, pork, and beef.

This study aimed to evaluate lytic bacteriophage supplementation in pre-weaned dairy calves on disease occurrence, performance, and biochemical parameters. Two hundred Holstein × Gyr crossbred female calves were divided into two groups: CON, no supplementation; and PHAGE, bacteriophage supplementation (1 g·d−1) from day 3 until day 70 of life. Calves were monitored daily for age of first diarrheal episode and its duration.

Spoiled silages can harbor pathogenic and antimicrobial-resistant microbes. The potential of some antimicrobial additives to inhibit certain pathogenic and antimicrobial-resistant bacteria in air-exposed silage was measured using pure and mixed bacterial cultures. With pure cultures, laurate and monolaurin (5 mg·mL−1) caused decreases (P < 0.05) of 4 to >7 log10 colony-forming units (CFU)·mL−1 in Listeria monocytogenes and Enterococcus faecalis compared to controls.

Chicken Farmers of Canada has been progressively phasing out prophylactic use of antibiotics in broiler chicken production. Consequently, hatcheries, veterinarians, and nutritionists have been mandated to contend with less reliance on the use of preventive antibiotics. A topical concern is the increased risk of proliferation of enteric pathogens leading to poor performance, increased mortality, and compromised welfare.

Type III secretion system (T3SS) effectors are key virulence factors that underpin the infection strategy of many clinically important Gram-negative pathogens, including Salmonella enterica, Shigella spp., enteropathogenic and enterohemorrhagic Escherichia coli and their murine equivalent, Citrobacter rodentium. The cellular processes or proteins targeted by the effectors can be common to multiple pathogens or pathogen-specific.

To disclose the antimicrobial susceptibility and wide adaptability of commonly occurring genotypes of Salmonella enterica serovar Typhimurium, the antimicrobial resistance and multilocus sequence typing (MLST) profiles of 196 Salmonella Typhimurium isolates (136 from food-producing animals, 19 from environments, 15 from markets, and 26 from humans) in China between 2007 and 2019 were analyzed.

Nontyphoidal Salmonella is a leading cause of foodborne illnesses, and concentrated animal production such as commercial mink farming can be a reservoir.

Enterohemorrhagic Escherichia coli are an important pathogen causing food poisoning. The rapid detection of viable E. coli O157 in vegetables and fruits at single-cell level is critical because of the low infective dose of this pathogen. In this study, an immunomagnetic flow cytometry (IMFC)-based method was developed to detect E. coli O157 in lettuce and strawberries inoculated with 1 CFU/25 g.

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) has gained interest in veterinary medicine due to its zoonotic potential. Currently, little information is available on the genotypic and virulence characteristics of MRSA isolates detected in Nigerian abattoirs.

In Latin America, nontyphoidal Salmonella (NTS) is one of the most important etiological agents of foodborne infections; it can survive in soil, water, and food even after processing. Here, we aimed to perform a systematic review by collecting data on the prevalence, serotypes, and antimicrobial resistance (AMR) of NTS isolated from different food products in Latin America, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Listeria monocytogenes is a ubiquitous Gram-positive foodborne pathogen that is responsible for listeriosis in both humans and several animal species. The bacterium secretes a pore-forming cholesterol-dependent cytolysin, listeriolysin O (LLO), a major virulence factor involved in the activation of cellular processes. The ability of LLO to lyse erythrocytes is a measure of LLO activity. We used hemolytic activity assay to screen the LLO inhibitors.

Listeriosis is a rare bacterial infection associated with foodborne illness that can result in septicemia, a serious acute outcome. Sepsis is responsible for one in three deaths during hospitalization. The objective of this study was to conduct a systematic review and meta-analysis to estimate the proportion of Listeria monocytogenes infections resulting in septicemia.

Campylobacteriosis is one of the most common bacteria causing human gastroenteritis. Poultry is a major reservoir of Campylobacter spp. as well as the main source of transmission. Due to the increased occurrence of campylobacteriosis, poultry slaughterhouses are under pressure to deliver carcasses with low contamination. However, a few studies have been carried out to evaluate Campylobacter contamination of broiler carcasses in Brazilian slaughter lines.

Staphylococcus aureus (S. aureus) is one of the major opportunistic foodborne pathogens as well as a source of human and animal infections. As surveillance of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) is limited in ice cream, a total of 240 ice cream samples were collected from three cities in Shaanxi province, China, and screened for S. aureus.

In August 2016, the Wisconsin Department of Health Services notified the U.S. Centers for Disease Control and Prevention of multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg infections in people who reported contact with dairy calves. Federal and state partners investigated this to identify the source and scope of the outbreak and to prevent further illnesses.