Consumers's Willingness to Pay for Avoiding Salmonella Infection

Salmonellosis is a widely known infectious disease in Hungary that played dominant role between 1960 and 1996 and remained one of the top food-borne illnesses to these days with an estimated total number of 96 048 cases (2019). Beside direct costs of treatment, indirect costs are also significant on the level of population. Among indirect costs, consumer well-being losses are difficult to be estimated. For this purpose, the willingness to pay (WTP) method is used most frequently that measures the cost an individual would undertake to avoid a certain harm. For the well-being loss estimation, the data of National Food Chain Safety Authority's annual consumer survey was used, in which 323 respondents gave evaluable answer to the open-ended WTP question. Results indicate that an average respondent would pay 18.6 EUR to avoid salmonellosis. Main factors affecting WTP were size of family and number of children. The numbers indicate that the consumer well-being loss could be about 1 786 060 EUR annually, resulting from the multiplication of the estimated number of annual salmonellosis cases and the average WTP value. It can be concluded that consumer well-being losses alone would call for further interventions in Salmonella eradication, not to mention other – more direct – cost elements

Identification of sites of injury in Lactobacillus bulgaricus during heat stress

Heat resistance of Lactobacillus bulgaricus in skimmed milk at 62°, 64°, 65° and 66°C was studied. The response to increasing temperatures in this range was not linear, with temperatures at 65°C and above giving a lower survival rate than would be predicted from experiments at lower temperatures. To identify sites of injury at these temperatures, chemical markers were used. Heating at 64°C and below resulted in damage to the cytoplasmic membrane. At temperatures of 65°C and above chemical markers also indicated damage in the cell wall and proteins. Using differential scanning calorimetry analysis of whole cells of Lact. bulgaricus seven main peaks were observed (l–51, m1–61, m2–73, n–80, p–89, q–100,r–112°C). Three of these peaks (lr, mr and pr) were the result of reversible reactions. Analysis of cell fractions identified the cell structure involved in giving rise to each of the three reversible peaks; lr, cell membrane lipids, mr, ribosomes, and pr, DNA. The evidence presented in this paper shows that irreversible reactions in the cell ribosomes are a critical site of damage in Lact. bulgaricus during heat stress in liquid media at 65°C and above

The Importance of Protein Fingerprints in Bacterial Identification: The Maldi-Tof Technique

The available literary sources suggest the general applicability and benefits of the Matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) in the field of microbiological identification including food quality and safety, and the clinical field.  Due to its high reliability, MALDI-TOF might generally be the alternative to the sequence-based and serological-based methods. The essence of the technique is to map the unique protein pattern of microbes that contributes to characterizing a wide variety of microorganisms, including bacteria, fungi, and viruses. On the other hand, these applications only have reliable results under certain conditions (homogeneous infection, adequate cell count, appropriate separation technique). In this review, we focused on the application of MALDI-TOF MS for the environmental field where it has significant potential in the identification, differentiation, and categorization of environmental samples which includes (soil, water, and air), furthermore, some challenges, especially in case of the extreme conditions environment and summarize developments that have been enabled for routine application in the field of environment

Enhanced heat resistance of Listeria innocua as a surrogate of Listeria monocytogenes after sublethal heat treatment

Abstract Its ability to survive under different environmental conditions makes Listeria monocytogenes a critical concern for food safety. When the microorganisms are exposed to sublethal heat treatment above their optimum growth temperature, they increase stress adaptation for further heat treatments. In order to investigate heat stress resistance of L. monocytogenes, L. innocua as a surrogate was exposed to sublethal heat at 46 °C for 30 and 60 min, prior to heat treatment at 60 °C. There was no significant difference in D60°C values between samples exposed to sublethal heat for 30 min and non-pre-heat-treated samples (control) (P > 0.05). In comparison, sublethal heat treatment for 60 min caused a significant increase in D60°C values compared to control samples (P < 0.05). Additionally, cluster analysis of mass spectra obtained from MALDI-TOF was analysed by discriminant analysis of principal components (DAPC) for sublethal heat treatment at 46 °C for 30 min and control group to check stress response at the proteomic level. However, differentiation of stress responses by distinct clusters was not revealing

Estimation of the occurrence of foodborne salmonellosis in Hungary

While in developed countries research findings are available on the estimation of the realistic number of different diseases and their economic impact at social level, in Central and Eastern European countries these country specific data are neither sufficient nor reliable. This study partially fills the gap and gives a picture of the real number of foodborne salmonellosis in Hungary. In the spring of 2017, a survey about diarrhoeal and foodborne diseases was conducted by interviewing 1001 adults (over the age of 18). Our survey showed that approximately 18 times more individuals are suffering from Salmonella infection than it is assumed under the national and international epidemiological database. Based on our estimation, the annual number of foodborne salmonellosis may range from 91 242 to 105 606 in Hungary. In this paper a methodology has been developed to estimate the true occurrence of this disease. Our results can be used to calculate the costs-benefit ratios of future salmonellosis prevention programmes and inform decision-makers on the effectiveness of Salmonella-related measures in the area of food safety

Searching for Antagonistic Activity of Bacterial Isolates Derived from Food Processing Environments on Some Food-Borne Pathogenic Bacteria

Bacterial strains with inhibitory effect on Salmonella Hartford, Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli, respectively, were isolated. Out of the 64 bacteria originated from food processing environments, 20 could inhibit at least one of the tested pathogens, and it was proved that growth decline of the pathogenic bacteria was more remarkable by co-culturing than by using cell-free supernatants of the isolates. Seven different genera (Pseudomonas, Bacillus, Paenibacillus, Macrococcus, Staphylococcus, Serratia, and Rothia) reduced the pathogens’ growth during the time period of analysis, and the strongest inhibitory effect was observed after 24 h between 15 and 30 °C. Sensitivity of the tested human pathogenic bacteria against the inhibitory strains was distinct, as Y. enterocolitica could be inhibited by numerous isolates, while S. Hartford proved to be the most resistant. Our results reveal that the isolated bacteria or their excreted metabolites could hinder pathogen growth when used in sufficient quantities

Effect of electron beam irradiation and the presence of antibiotics on the population ratio of resistan/sensitive bacterial cultures in model wastewater matrix with antibiotics and bacteria added prior to advanced oxidation treatment

Control strategies against the spread of antibiotic resistance should be considered in wastewater treatment plants. It is important to understand how resistant bacteria behave in the presence of trace amounts of antibiotics, in order to implement appropriate measures. In our work, we examined the population dynamics of resistant/sensitive Staphylococcus aureus co-cultures. On the one hand, we gained insight into the effect of trace amounts of antibiotics (piperacillin and erythromycin) on bacteria in different wastewater matrices, and on the other hand, we studied the applicability of electron radiation to eliminate the antibacterial effect. Based on our results, trace amounts of antibiotics act on the resistant strain. Presumably, it triggers biological processes in resistant bacteria that do not provide a competitive benefit but disadvantage over the sensitive subtype, and the trace level of the antibiotic present does not appear to affect the sensitive strains. The effect of these conditions on population dynamics is reduced with the use of accelerated electrons, presumably due to the fact that the decomposition products of the components of the effluent matrix (such as humic acid) also contribute to the chemical transformations. Furthermore, it has become apparent that the presence of trace amounts of antibiotics on the one hand initiates biochemical processes in the resistant subtype and on the other hand sensitizes bacteria to the attack of free radicals generated during electron beam treatment. It is clear that more understanding is needed on the effects of trace level of antibiotics in environmental waters on the cellular response and population behavior of resistant bacterial cultures