The impact of lactic acid bacteria with antimicrobial properties on biodegradation of polycyclic aromatic hydrocarbons and biogenic amines in cold smoked pork sausages

The influence of surface treatment with lactic acid bacteria (LAB), previously cultivated in an alternative substrate, on the formation of polycyclic aromatic hydrocarbons (PAHs) and biogenic amines (BAs) in cold smoked pork meat sausages was investigated. Moreover, sausages treatment with LAB after the smoking on PAHs content changes was evaluated. Additionally, the inhibitory effects of LAB metabolites on food spoilage bacteria was determined using the agar well diffusion assay method. The metabolites of Pediococcus acidilactici KTU05-7, Pediococcus pentosaceus KTU05-9 and Lactobacillus sakei KTU05-6 strains showed good inhibitory properties against tested pathogenic and food spoilage bacteria. Moreover L. sakei produced bacteriocins inhibited the growth of Pseudomonas aeruginosa and Escherichia coli. Furthermore, the treatment of sausages surface with LAB before smoking decreased the content of cadaverine and spermidine, whereas the treatment of sausages surface with LAB after smoking decreased the content of putrescine (approx. 53% when L. sakei and P. acidilactici were applied) or totally eliminated (applying P. pentosaceus) from outer layers and centre of sausages. The application of LAB for sausages treatment before and after smoking significantly decreased both benzo[a]pyrene and chrysene decreasing (p < 0.05). The results also confirm that potatoes juice could be used as an alternative substrate for LAB cultivation, and the obtained fermented bioproducts could be applied for surface treatment of cold smoked pork sausages in case to reduce microbial contamination, and PAHs content in final product

Legionella pneumophila Seropositivity-Associated Factors in Latvian Blood Donors

Continuous environmental exposure of humans to Legionella may induce immune responses and generation of antibodies. The aim of this study was to investigate the seroprevalence of Legionella pneumophila serogroups (SG) 1–6 in the general healthy population and identify the associated host-related and environmental risk factors. L. pneumophila SG 1–6 seroprevalence among a total of 2007 blood samples collected from healthy donors was 4.8%. Seroprevalence was higher in women (5.9%) than men (3.3%) and in areas with a larger number of inhabitants, ranging from 3.5% in rural regions to 6.8% in the capital, Riga. Blood samples from inhabitants of apartment buildings tested positive for L. pneumophila in more cases (5.8%) compared to those from inhabitants of single-family homes (2.7%). Residents of buildings with a municipal hot water supply system were more likely to be seropositive for L. pneumophila (OR = 3.16, 95% CI 1.26–7.91). Previous episodes of fever were additionally identified as a risk factor (OR = 2.42, 95% CI 1.43–4.1). In conclusion, centralized hot water supply, female gender and previous episodes of fever were determined as the main factors associated with L. pneumophila seropositivity in our study population