Research Publications (Food Safety)

We report the development of real-time PCR assays for genotyping Clostridium botulinum group III targeting the newly defined C. novyi sensu lato group; the nontoxic nonhemagglutinin (NTNH)-encoding gene ntnh; the botulinum neurotoxin (BoNT)-encoding genes bont/C, bont/C/D, bont/D, and bont/D/C; and the flagellin (fliC) gene. The genetic diversity of fliC among C. botulinum group III strains resulted in the definition of five major subgroups named fliC-I to fliC-V.

Bacillus cereus is an opportunistic human pathogen responsible for food poisoning and other, nongastrointestinal infections. Due to the emergence of multidrug-resistant B. cereus strains, the demand for alternative therapeutic options is increasing. To address these problems, we isolated and characterized a Siphoviridae virulent phage, PBC1, and its lytic enzymes. PBC1 showed a very narrow host range, infecting only 1 of 22 B. cereus strains.

Strawberries are an important fruit in Belgium in both production and consumption, but little information is available about the presence of Salmonella and Shiga toxin-producing Escherichia coli (STEC) in these berries, the risk factors in agricultural production, and possible specific mitigation options. In 2012, a survey was undertaken of three soil and three soilless cultivation systems in Belgium. No Salmonella spp. were isolated.

Small- and medium-size farms in the mid-Atlantic region of the United States use varied agricultural practices to produce leafy greens during spring and fall, but the impact of preharvest practices on food safety risk remains unclear. To assess farm-level risk factors, bacterial indicators, Salmonella enterica, and Shiga toxin-producing Escherichia coli (STEC) from 32 organic and conventional farms were analyzed.

Influenza A virus (IAV) has its natural reservoir in wild waterfowl, and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate [OC]), stockpiled as Tamiflu for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may exert evolutionary pressure on avian IAV in waterfowl, resulting in the development of resistant viral variants.

In this studythe chemical composition of Pulicaria gnaphalodes essential oil was evaluated by gas chromatography mass spectrometry analysis. Among the 34 components, alpha-pinene (32.2%) and 1–8-cineole (10.9%) were the major components. The antibacterial and antifungal activity of essential oil and aqueous, ethanolic and methanolic extracts from Pu. gnaphalodes against some bacteria and fungi were investigated.

Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. The ability to sensitively trace and identify this active toxin is important for food safety. This study evaluated a nonradioactive, sensitive, in vitro cell-based assay, based on B. cereus toxin inhibition of green fluorescent protein (GFP) synthesis in transduced monkey kidney Vero cells, combined with plant extracts or plant compounds that reduce viable count of B.

The aim of this study was to investigate the effect of ultraviolet (UV)-C treatment on the decrease of the inoculated Staphylococcus aureus population in precooked shredded bullfrog meat. The precooked meat was inoculated with 8 log cfu/g of S. aureus. The packaged bullfrog's back meat was then exposed to low (0.65 mW/s/cm2), medium (1.04 mW/s/cm2) and high (1.68 mW/s/cm2) UV-C intensities over different time intervals (60, 100 and 140 s).

Publication date: September 2015
, Volume 55
Author(s): Yanzhen Wang , Xiaobin Zeng , Zhengkun Zhou , Ke Xing , Akalate Tessema , Hong Zeng , Jun Tian

Publication date: September 2015
, Volume 55
Author(s): Yimin Zhang , Charles E. Carpenter , Jeff R. Broadbent , Xin Luo

Publication date: September 2015
, Volume 55
Author(s): Songbai Wang , Yan Zhang , Wenting An , Yanli Wei , Nan Liu , Yiping Chen , Shaomin Shuang

Worldwide, noroviruses are a leading cause of gastroenteritis. They can be transmitted from person to person directly or indirectly through contaminated food, water, or environments. To estimate the proportion of foodborne infections caused by noroviruses on a global scale, we used norovirus transmission and genotyping information from multiple international outbreak surveillance systems (Noronet, CaliciNet, EpiSurv) and from a systematic review of peer-reviewed literature.

Publication date: 2 June 2015
, Volume 202
Author(s): M. Ferrara , G. Perrone , A. Gallo , F. Epifani , A. Visconti , A. Susca

Lucia Bronchalo-Vicente, Estela Rodriguez-Del Rio, Javier Freire, Ricardo Calderon-Gonzalez, Elisabet Frande-Cabanes, Jose Javier Gomez-Roman, Hector Fernández-Llaca, Sonsoles Yañez-Diaz, Carmen Alvarez-Dominguez

Aims
(1) To study the effects of cold shock on E. coli O157:H7 cells. (2) To determine if cold-shocked E. coli O157:H7 cells at stationary and exponential phases are more pressure resistant than their non-cold shocked counterparts. (3) To investigate the baro-protective role of growth media (0.1% peptone water, beef gravy and ground beef).

Shiga toxin-producing Escherichia coli (STEC) O26 infections can be comparable with STEC O157 infections in severity of the acute haemolytic-uremic syndrome HUS and long-term sequelae. Among O26 STEC isolates, highly virulent clone O26:H11/H- Sequence Type 29 (ST 29) emerged in Germany in mid-1990s and spread to European countries. However, up to date, no STEC O26:H11/H- belonging to ST29 has been documented in Poland.

The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. Although the actin-related protein 2/3 (Arp2/3) complex is necessary and sufficient for Listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation.

Veal cutlets were surface inoculated with ca. 6.6 cfu/g of an eight-strain rifampicin-resistant cocktail of Shiga toxin-producing Escherichia coli (STEC) (O26:H11, O45:H2, O103:H2, O104:H4, O111:H-, O121:H19, O145:NM and O157:H7). Cutlets were mechanically tenderized and cordon bleu was prepared by adding slices of ham and cheese between two cutlets prior to batter/breading and cooking. Fully assembled cordon bleu were cooked in preheated (191.5C) extra virgin olive oil (45 mL) on a griddle.

Publication date: September 2015
, Volume 55
Author(s): Steffen Mueller , Sara M. Handy , Jonathan R. Deeds , Gideon O. George , Wendy J. Broadhead , Sian E. Pugh , Stephen D. Garrett

Publication date: 2 June 2015
, Volume 202
Author(s): Gulsun Akdemir Evrendilek

Sejeong Kim, Heeyoung Lee, Soomin Lee, Yohan Yoon, Kyoung-Hee Choi

Andrea Hodgson, Eric M. Wier, Kai Fu, Xin Sun, Hongbing Yu, Wenxin Zheng, Ho Pan Sham, Kaitlin Johnson, Scott Bailey, Bruce A. Vallance, Fengyi Wan

We developed a simple and cheap assay for quantitatively detecting ochratoxin A (OTA) in wine. A DNA aptamer available in literature was used as recognition probe in its molecular beacon form, i.e., with a fluorescence-quenching pair at the stem ends. Our aptabeacon could adopt a conformation allowing OTA binding, causing a fluorescence rise due to the increased distance between fluorophore and quencher. We used real-time PCR equipment for capturing the signal.

Keila Martin-Betancor, Ismael Rodea-Palomares, Angeles Muñoz Martin, Francisco Leganes and Francisca FERNÁNDEZ-PIÑAS A self-luminescent bioreporter strain of the unicellular cyanobacterium Synechococcus sp. PCC 7942 was constructed by fusing the promoter region of the smt locus (encoding the transcriptional repressor SmtB and the metallothionein SmtA) to luxCDABE from Photorhabdus luminescens; the sensor smtB gene controlling the expression of smtA was cloned in the same vector.