Loreta Šernienė

Prevalence and genetic diversity of enteropathogenic Yersinia spp. in pigs at farms and slaughter in Lithuania.

The prevalence of enteropathogenic Yersinia spp. in pigs at farms and slaughter in relation to potential farming risk factors in Lithuania was examined. Pig faeces and carcase swab samples from 11 farms were studied at slaughterhouses. Nine of the 11 farms were visited again 3-5 months later, and pooled feacal samples and environmental samples were collected. Pathogenic Yersinia enterocolitica was found in 64% and Yersinia pseudotuberculosis in 45% of the sampled pig farms. All obtained isolates belonged to bioserotypes 4/O:3 and 2/O:3, respectively. Low biosecurity level was associated with a high prevalence of Y. enterocolitica on farms. Characterization with PFGE of 64 Y. enterocolitica and 27 Y. pseudotuberculosis isolates revealed seven and two different genotypes, respectively. Dominant enteropathogenic Yersinia spp. genotypes were obtained in both pig feacal and carcase samples. The high contamination of pig carcases (25%) with enteropathogenic Yersinia spp. may be an important factor contributing to the high incidence of human yersiniosis in Lithuania.

Importance of the producer on retail broiler meat product contamination with Campylobacter spp.

BACKGROUND Campylobacter spp. are a leading cause of human bacterial gastroenteritis worldwide, with poultry meat being considered the most important source of the infection. To obtain data on broiler meat contamination with Campylobacter spp. in Lithuania, the occurrence, counts and genotypes of these pathogens on raw broiler meat products from different producers were examined. RESULTS Out of 312 broiler meat product samples examined, 46.8% were contaminated with Campylobacter spp. Campylobacter jejuni was identified in 51.4% and Campylobacter coli in 37.7% of positive samples. Campylobacter jejuni was more frequently found in the warm period (April-October) and C. coli in the cold period (November-March) of the year (P < 0.05). The overall mean count of Campylobacter spp. was 3.55 and 3.50 log10 colony-forming units (CFU) on wings and drumsticks respectively. The occurrence and counts of Campylobacter spp. varied significantly between producers examined (P < 0.05). Analysis of flaA-RFLP genotyping revealed C. jejuni genotypes common to all producers as well as producer-specific genotypes. CONCLUSION Both the occurrence and counts of Campylobacter spp. on broiler meat products were producer-dependent, so this should be kept in mind when risk-based control measures at national level are applied.

Trends in monitoring residues of prohibited pharmacologically active substances in primary products of animal origin in Lithuania and the European Union from 1999 to 2008.

Group A pharmacologically active substances monitoring data in the Republic of Lithuania (LR) during the period 1999–2008 are presented. Peer review is based on data taken from residue monitoring plans of the years 1999–2008 and the National Food and Veterinary Risk Assessment Institute (NFVRAI) reports on analyses performed in various foods. The data were analysed with the SPSS statistical package, using descriptive statistics and generalised linear modelling methods. Retrospective analysis of residue monitoring results showed that food processed from animal products presented no risk to consumers as regards to substances of Group A1, A2, A3, A4 and A5. One substance of Group A6 (chloramphenicol) was detected in bovine milk in 2003 (9%), 2006 (2%) and 2008 (1.4%). The decreasing trend is confirmed by statistical data analyses, where year of monitoring (P ≤ 0.0001), product (P ≤ 0.1) and their interaction (P ≤ 0.0001) proved the positive effect of the monitoring system.

Optimization of a capillary zone electrophoresis-contactless conductivity detection method for the determination of nisin

Determination of natural preservatives using electrophoretic or chromatographic techniques in fermented milk products is a complex task due to the following reasons: (i) the concentrations of the analytes can be below the detection limits, (ii) complex matrix and comigrating/coeluting compounds in the sample can interfere with the analytes of the interest, (iii) low recovery of the analytes, and (iv) the necessity of complex sample preparation. The aim of this study was to apply capillary zone electrophoresis coupled with contactless conductivity detection for the separation and determination of nisin in fermented milk products. In this work, separation and determination of natural preservative–nisin in fermented milk products is described. Optimized conditions using capillary zone electrophoresis coupled with capacitance‐to‐digital technology based contactless conductivity detector and data conditioning, which filter the noise of the electropherogram adaptively to the peak migration time, allowed precise, accurate, sensitive (limit of quantification: 0.02 μg/mL), and most importantly requiring very minute sample preparation, determination of nisin. Sample preparation includes following steps: (i) extraction/dilution and (ii) centrifugation. This method was applied for the determination of nisin in real samples, i.e. fermented milk products. The values of different nisin forms were ranging from 0.056 ± 0.003 μg/mL to 9.307 ± 0.437 μg/g.

Broiler health status has a major negative impact on broiler flock contamination with Campylobacter spp. in Lithuania

Abstract The objective of this study was to determine risk factors for Campylobacter infection in broiler flocks in Lithuania. Each broiler flock was tested for the contamination with Campylobacter spp., and various broiler farm, flock and abattoir as well as the weather-associated characteristics were analysed using the statistical package SPSS. Study revealed that 59.3% of the examined broiler flocks were contaminated with Campylobacter spp. Statistical analysis revealed that broiler flock contamination with Campylobacter was abattoir- and farm-dependent. Among a number of risk factors (e.g. the number of broiler houses at the farm, the type of ventilation system, the presence of the anteroom and boot security, etc.) identified, two broiler health-associated characteristics: (i) broiler age and (ii) the average weight per bird at abattoir had the highest impact on the increased prevalence of Campylobacter spp. in broilers. According to our results broiler health status has a major negative effect on broiler flock contamination with Campylobacter. Thus, it needs to be considered when improving control of Campylobacter spp. in broilers.