Research Publications (Food Safety)

Abstract

Concerns have been raised that in-feed chlortetracycline (CTC) may increase antimicrobial resistance (AMR), specifically tetracycline-resistant (TETr) Escherichia coli and third-generation cephalosporin-resistant (3GCr) E. coli. We evaluated the impact of a 5-day in-feed CTC prophylaxis on animal health, TETr E. coli, and 3GCr E. coli.

Campylobacter is the leading cause of human gastroenteritis worldwide. Wild birds, including American crows, are abundant in urban, suburban, and agricultural settings and are likely zoonotic vectors of Campylobacter. Their proximity to humans and livestock increases the potential spreading of Campylobacter via crows between the environment, livestock, and humans. However, no studies have definitively demonstrated that crows are a vector for pathogenic Campylobacter.

Acetylation of small molecules is widespread in nature, and in some cases, cells use this process to detoxify harmful chemicals. Streptomyces species utilize a Gcn5 N-acetyltransferase (GNAT), known as Bar, to acetylate and detoxify a self-produced toxin, phosphinothricin (PPT), a glutamate analogue.

In 2014, the identification of stone fruits contaminated with Listeria monocytogenes led to the subsequent identification of a multistate outbreak. Simultaneous detection and enumeration of L. monocytogenes were performed on 105 fruits, each weighing 127 to 145 g, collected from 7 contaminated lots. The results showed that 53.3% of the fruits yielded L.

Publication date: March 2017
, Volume 125

Author(s): Dhekra Mhalla, Amira Bouaziz, Karim Ennouri, Rachid Chawech, Slim Smaoui, Raoudha Jarraya, Slim Tounsi, Mohamed Trigui

Online Ahead of Print.

Online Ahead of Print.

Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A–E) according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans.

Publication date: April 2017
Source:LWT - Food Science and Technology, Volume 77

Author(s): Maria Sanz-Puig, Patricia Moreno, M. Consuelo Pina-Pérez, Dolores Rodrigo, Antonio Martínez

Campylobacter cause morbidity and considerable economic loss due to hospitalization and post infectious sequelae such as reactive arthritis, Guillain Barré- and Miller Fischer syndrome...

Clostridium perfringens is a major cause of histotoxic and intestinal infections of humans and other animals. This Gram-positive anaerobic bacterium can produce up to three sialidases named NanH, NanI, and NanJ. The role of sialidases in histotoxic infections, such as gas gangrene (clostridial myonecrosis), remains equivocal.

Publication date: 2 February 2017
, Volume 242

Author(s): Ying-Chen Wu, Chih-Ming Chen, Chih-Jung Kuo, Jen-Jie Lee, Pin-Chun Chen, Yi-Chih Chang, Ter-Hsin Chen

Our recent study demonstrated that virulent Coxiella burnetii Nine Mile phase I (NMI) is capable of infecting and replicating within peritoneal B1a cells and that B1a cells play an important role in host defense against C. burnetii infection in mice. However, it remains unknown if avirulent Nine Mile phase II (NMII) can infect and replicate in B1a cells and whether NMI and NMII can differentially interact with B1a cells.

Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp.

At present, there is no vaccine for enterotoxigenic Escherichia coli (ETEC), an important cause of diarrheal illness. Nevertheless, recent microbial pathogenesis studies have identified a number of molecules produced by ETEC that contribute to its virulence and are novel antigenic targets to complement canonical vaccine approaches. EtpA is a secreted two-partner adhesin that is conserved within the ETEC pathovar.

Enoyl-acyl carrier protein reductase catalyzes the last step in each elongation cycle of type II bacterial fatty acid synthesis and is a key regulatory protein in bacterial fatty acid synthesis. Genes of the facultative intracellular pathogen Listeria monocytogenes encode two functional enoyl-acyl carrier protein isoforms based on their ability to complement the temperature-sensitive growth phenotype of Escherichia coli strain JP1111 [fabI(Ts)].

Intestinal epithelial cells provide an important colonization niche for Salmonella enterica serovar Typhimurium during gastrointestinal infections. In infected epithelial cells, a subpopulation of S. Typhimurium bacteria damage their internalization vacuole, leading to escape from the Salmonella-containing vacuole (SCV) and extensive proliferation in the cytosol.

Brucella species are facultative intracellular bacteria that cause brucellosis, a chronic debilitating disease significantly impacting global health and prosperity. Much remains to be learned about how Brucella spp. succeed in sabotaging immune host cells and how Brucella spp. respond to environmental challenges. Multiple types of bacteria employ the prokaryotic second messenger cyclic di-GMP (c-di-GMP) to coordinate responses to shifting environments.

Campylobacter jejuni is a helix-shaped enteric bacterial pathogen and a common cause of gastroenteritis. We recently developed a mouse model for this human pathogen utilizing the SIGIRR-deficient mouse strain, which exhibits significant intestinal inflammation in response to intestinal C. jejuni infection. In the current study, this mouse model was used to define whether C.

Neutrophils are essential components of immunity and are rapidly recruited to infected or injured tissue. Upon their activation, neutrophils release granules to the cell's exterior, through a process called degranulation. These granules contain proteins with antimicrobial properties that help combat infection.

Publication date: April 2017
Source:LWT - Food Science and Technology, Volume 77

Author(s): Patrizia Losito, Pierina Visciano, Marisa Genualdo, Rosa Satalino, Marco Migailo, Angelo Ostuni, Arianna Luisi, Giorgio Cardone

Online Ahead of Print.

Online Ahead of Print.