Research Publications (Food Safety)

by Jelena Prpić, Tomislav Keros, Marko Vucelja, Linda Bjedov, Oktavija Đaković Rode, Josip Margaletić, Boris Habrun, Lorena Jemeršić

The emergence of multidrug-resistant bacterial strains in diverse settings has been reported globally. In the Philippine shrimp aquaculture industry, antibiotics are used for the treatment of bacterial diseases during the production cycle. We report the draft genome of Vibrio parahaemolyticus PH698, a multidrug-resistant strain isolated from a Philippine shrimp farm.

Salmonella enterica is a natural bacterial pathogen of humans and animals that causes systemic infection or gastroenteritis. During systemic infection, Salmonella generally resides within professional phagocytes, typically macrophages, whereas gastroenteritis is caused by infection of epithelial cells. We are only beginning to understand which host pathways contribute to Salmonella survival in particular cell types.

qnr genes are found in aquatic bacteria and were present in the bacterial community before the introduction of synthetic quinolones. Their natural functions are unknown. We evaluated expression of chromosomal qnr in Vibrio species in response to environmental stresses and DNA-damaging agents.

In Enterobacteriaceae, quinolone resistance is largely attributed to mutations in the quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC, and parE and plasmid-mediated quinolone resistance (PMQR) genes [e.g., qnr genes, aac(6′)-Ib-cr, or qepA].

Multidrug efflux pumps play an important role in antibiotic resistance in bacteria. In Pseudomonas aeruginosa, the MexXY pump provides intrinsic resistance to many antimicrobials, including aminoglycosides. The expression of the mexXY operon is negatively regulated by the MexZ repressor. This repression is alleviated in response to antibiotic-induced ribosome stress, which results in increased synthesis of the antirepressor ArmZ, interacting with MexZ.

Spores are required for long-term survival of many organisms, including most fungi. For the majority of fatal human fungal pathogens, spore germination is the key process required to initiate vegetative growth and ultimately cause disease. Because germination is required for pathogenesis, the process could hold fungus-specific targets for new antifungal drug development.

Author(s): Tiago de Melo Nazareth, Manuel Alonso-Garrido, Oana Stanciu, Jordi Mañes, Lara Manyes, Giuseppe Meca

Author(s): Paula Vasconcelos Costa, Luiza Vasconcellos, Ingrid Camelo da Silva, Valéria de Mello Medeiros, Stephen James Forsythe, Marcelo Luiz Lima Brandão

Author(s): Ling Jin, Ting Li, Bin Wu, Tan Yang, Dengchao Zou, Xuehua Liang, Liwen Hu, Ganhui Huang, Jinsheng Zhang

Author(s): L. Heras-González, J.A. Latorre, M. Martinez-Bebia, D. Espino, F. Olea-Serrano, M. Mariscal-Arcas

Author(s): Wankui Jiang, Qinqin Gao, Lu Zhang, Hui Wang, Mingliang Zhang, Xiaoan Liu, Yidong Zhou, Zhijian Ke, Chenglong Wu, Jiguo Qiu, Qing Hong

Author(s): Eloy Navarro-León, Juan Manuel Ruiz, Alfonso Albacete, Begoña Blasco

Author(s): Fuyu Guo, Changfeng Ding, Zhigao Zhou, Fengxiang Han, Ronggui Tang, Gaoxiang Huang, Xingxiang Wang

Author(s): Biao Hu, Bin Tong, Ying Xiang, Se-Ruo Li, Zhu-Xia Tan, Hui-Xian Xiang, Lin Fu, Hua Wang, Hui Zhao, De-Xiang Xu

DNA phosphorothioation is widely used in antisense drugs. DNA PT modification also exists in bacteria. Using a purified enzyme complex, we show here for the first time how the inert DNA backbone is activated for the exchanging of oxygen with sulfur. Abstract Phosphorothioation (PT) involves the replacement of a nonbridging phosphate oxygen on the DNA backbone with sulfur. In bacteria, the procedure is both sequence‐ and stereo‐specific.

Fluorescent pseudomonads colonizing wheat ears have a high antagonistic potential against phytopathogenic fungi. To check this hypothesis, the bacterial antagonist Pseudomonas simiae 9 rif+/kan+ was spray-inoculated onto the ears of winter wheat in a locally demarcated experimental field plot. Fusarium and Alternaria fungi naturally occurring on the ears and the formation of their mycotoxins in the ripe grains were investigated.

ABSTRACT Low pathogenicity avian influenza (LPAI) H9N2, highly pathogenic avian influenza (HPAI) H5N1, and H5N8 circulate in Egyptian poultry and cause veterinary and public health burdens. In response, AIV vaccines are commonly used. The main objective of this study was to develop a broad, cross-protective, trivalent vaccine based on circulating AIVs in Egypt.

ABSTRACT We evaluated the combination of immunomagnetic separation (IMS), multiple displacement amplification (MDA), and real-time PCR to detect Salmonella from poultry environmental samples. The limits of detection (LODs) of IMS-MDA real-time PCR with different culture enrichment hours (0, 4, 6, and 8 h) were determined in artificially inoculated litter samples from a specific pathogen-free (SPF) poultry farm.

Salmonella and Campylobacter are leading human foodborne pathogens commonly associated with poultry and poultry products, and several methods to control these pathogens have been applied to poultry production.

ABSTRACT Poultry meats can become contaminated with pathogenic bacteria through digesta leakage during processing. Reducing the bacteria load in digesta of market-aged broilers prior to processing reduces the incidence of fecal contamination at the processing plant. A lysozyme product was incorporated in a maltodextrin-based feed offered during the pre-shipping feed withdrawal period to reduce bacteria in ileal contents of market-aged broilers.

ABSTRACT The objective of this study was to assess the effect of dietary yeast products on broiler chickens challenged with salmonella lipopolysaccharide (LPS). The chicks were divided into 8 treatments with 6 replicates and 9 birds per replicate.

ABSTRACT Salmonella enteritidis (S. enteritidis) infection has been recognized as one of the most common bacterial causes of human gastroenteritis worldwide and is closely associated with eggs. Slightly acidic electrolyzed water (SAEW) is an emerging environmentally friendly technology for disinfecting eggshell surfaces to remove dirt and pathogenic microorganisms.

ABSTRACT Necrotic enteritis (NE) is a pervasive enteric disease responsible for large scale economic losses within the global poultry industry. The etiologic agent of NE is Clostridium perfringens (CP), an opportunistic pathogen that utilizes numerous extracellular toxins and glycoside hydrolases (GH) as key virulence and nutrient acquisition factors.

ABSTRACT This study was conducted to determine the effects of essential oils and organic acids (EOA) on Salmonella Enteritidis (S. Enteritidis) challenged chickens. One-day-old specific pathogen-free (SPF) chicks (250) were randomly assigned to 5 groups, with 50 birds in each group. The treatment groups were as follows: 1) basal diet, negative control group (NC); 2) basal diet + S.