Research Publications (Food Safety)

Conventional detection of Salmonella from foods involves enrichment and isolation on selective media which can significantly lengthen time to result. The objective of this study was to evaluate the utility of an accelerated plating procedure and the use of rapid screening devices for Salmonella detection. Fresh produce was inoculated with Salmonella at ~2.5, ~7.5 and ~25 cfu sample−1.

A total of 104 Listeria monocytogenes isolates from 330 fish samples from three countries were characterized by multiplex PCR for serogrouping and virulence markers determination and tested for antibiotics resistance. A 53.8% of the isolates belonged to serogroup 1/2a, 3a; 32% belonged to 1/2b, 3b, 7, 14.4% belonged to 4b, 4d, 4e, and 1% belonged to 1/2c, 3c. All isolates exhibited resistance to at least one antibiotic but the resistance rates varied among countries.

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.

Electronic noses (e-noses) have been used for environmental monitoring, standardization of medicinal flavourings, food safety tests, and diagnosis of infectious diseases based on the statistical analysis of volatile organic compounds (VOCs). Bovine tuberculosis (bTB) is officially diagnosed using the intradermal skin test (IST), which is time-consuming and labour-intensive. Therefore, a more convenient and rapid test with greater sensitivity would be advantageous as pre-screening test.

Probiotic enterococci can produce bacteriocins. Enterococcus faecium AL41 is an Enterocin M-producing, probiotic strain which has previously shown beneficial effect in broiler chickens. In this study it was used to control intestinal microbiota in farm ostriches in a 42-day experiment with an experimental group (EG, 40 ostriches) and a control group (CG, 46). In addition to feed mixture, the ostriches in EG received E.

The mechanisms of invasion and intracellular survival of Brucella are still poorly understood. Previous studies showed the two-component regulatory systems (TCSs) play an important role in the intracellular survival of Brucella. To investigate if TCSs involve in the virulence and cytotoxicity of Brucella melitensis (B. melitensis), we introduced a mutation into one of TCSs in chromosome II in B. melitensis 16M strain, and generated 16MΔTceSR, a mutant of B. melitensis 16M strain.

The objective of this study was to assess the genetic diversity of non-O157 STEC isolates from cattle. Multi-locus sequence typing (MLST) was used to identify and compare the sequence types (STs) of 43 non-O157 STEC cattle isolates using the EcMLST database curated by the STEC Center at Michigan State University. For the 43 isolates, 19 STs were identified and 10 of those STs were novel compared to those in EcMLST. For the 43 isolates, 19 different serotypes were identified.

Giardia intestinalis is a pathogen associated with foodborne outbreaks and Escherichia coli is commonly used as a marker of faecal contamination. Implementation of routine identification methods of G. intestinalis is difficult for the analysis of vegetables and the microbiological detection of E. coli requires several days. This study proposes a PCR-based assay for the detection of E. coli and G. intestinalis cysts using crude DNA isolated from artificially-contaminated lettuce. The G.

Essential oils have been found to exert antibacterial, antifungal, spasmolytic, and antiplasmodial activity and therapeutic effect in cancer treatment. In this study, the antibacterial activities of four main essential oils’ components (thymol (Thy), eugenol (Eug), berberine (Ber), cinnamaldehyde (Cin)) were evaluated against two foodborne pathogens, Listeria monocytogenes and Salmonella Typhimurium, either alone or in combination with streptomycin.

Vibrio vulnificus is a Gram-negative pathogen found in coastal and estuarine waters worldwide that can cause life threatening diseases. Characterization of the vcg (virulence correlated gene) or 16S rRNA alleles is used to distinguish virulent (clinical (C)-type) from presumably avirulent (environmental (E)-type) strains. However, some studies reported significant numbers of clinical strains belonging to the E-type.

Preservative agents determining the shelf life of cosmetic products must have effective antimicrobial activity while meeting safety requirements for topical use. In this study, we determined the antimicrobial activity of 1,2-hexanediol against several Gram-positive and Gram-negative bacteria. Antimicrobial susceptibility tests have shown that 1,2-hexanediol exhibits broad-spectrum activity against Gram-positive and Gram-negative bacteria with MICs of 0.5 – 2% (v v−1).

The food safety criteria that have been incorporated in European regulation (EC) N°2073/2005 (Commission regulation, 2005), for Listeria monocytogenes in ready-to eat (RTE) foods, specify a maximum allowable concentration of 100 cfu.g−1 or ml−1. Some factors such as pH, salt and modified atmosphere packaging (MAP) are used to prevent the growth of L. monocytogenes in order to comply with the limit. Interactions between background microflora (BM) and L.

The presence of highly pathogen STEC in shellfish, upstream waters and sediment from coastal shellfish sites was evaluated using the ISO/TS-13136 method. Shellfish (oysters, mussels and cockles), water and sediment samples were collected monthly over a period of one year.

A modification of the UK reference and ISO 14189 TSCA medium for the enumeration of Clostridium perfringens from water coupled with a membrane filter transfer technique for testing for production of acid phosphatase was evaluated. The new tryptose cycloserine agar (TCA) medium, which lacks sodium metabisulphite but contains sodium pyruvate to improve recovery, allows the isolation and confirmation of Cl. perfringens within 18–24 h of sample processing.

In this study, we tested 15 naturally occurring isoflavones and their metabolites for their possible antibacterial properties against nine Gram-positive and Gram-negative bacteria. The in vitro antibacterial activity was determined using the broth microdilution method, and the results were expressed as minimum inhibitory concentrations (MICs).

Growth of enteropathogenic Escherichia coli E2348/69 was inhibited by bicarbonate in a dose-dependent manner, showing approximately 5% growth reduction at 5 mmol l−1 while kanamycin at 3.12 μg ml−1 inhibited growth by 15%, yet when kanamycin and bicarbonate were combined at these concentrations, inhibition increased to 80%. Unexpectedly, at bicarbonate concentrations >20 mmol l−1 enhancement of the antibiotic activity virtually disappeared, i.e. there was a paradoxical Eagle-like effect.

Abstract