A metabenztiazuron fotokémiai bomlása különböző adalékanyagok jelenlétében

A növényvédő szerek a talajban számos abiotikus és biotikus átalakulási folya-maton mehetnek keresztül. A talajt alkotó anyagok hatását különböző adalékanya-gokkal lehet modellezni. Kutatásunk során titán-dioxidot, agyagásványt, humusz-anyagokat, és benzofenont – töltésátviteli komplex kialakítására – használtunk erre a célra. A kutatás célja az volt, hogy felmérje a metabenztiazuron (MBTA) termé-szetes körülmények között lehetséges bomlási útvonalait. A herbicid molekula és a benzofenon között kialakult töltésátviteli komplextől azt vártuk, hogy az energia transzfer hatékonyabbá tételével segítse a bomlást. A kísérletünk eredményei igazolták ezt a várakozást, mivel a metabenztiazuron bomlása a benzofenon jelenlétében volt a leggyorsabb. A huminsav eredő hatása a bomlás enyhe gátlása volt. A titán-dioxid és a montmorillonit kis mértékben növelte a metabenztiazuron fotokémiai bomlásának sebességét, de a titán-dioxid esetében ez nem tekinthető jelentős hatásnak

La culture politique de la Roumanie urbaine

The poor performance of the political system in Romania, still marked by disaffection and pervasive corruption, may be shaped by the lack of control from the citizens. Much more responsible towards its electoral basis, the Romanian political system would be more legitimate. The political performance and legitimacy would in turn make citizens more satisfied and eager to defend democratic values. The happy circle of civic control, responsivness, satisfaction and political performance may be started somehow. The research paper is an attempt to evaluate political culture in urban Romania as a source of political legitimacy and performance. We focus on the civic culture, this special association of knowledge and feelings about the political system that settle citizens to political communication, partisanship, social cooperation, political competence and, in the end, political action. By analysing survey data, we outline a meager civic culture in Romania, but also the hope for a future civic competence

Effects of cephalexin residues on the starter culture's microbial activity during the fresh cheese making process

The aim of our study was to investigate the carry-over of cephalexin from cow’s milk to cheese and whey, as well as, to study the potential impact of its presence on the microbial activity of the starter culture. Before cheese-making, the raw milk was artificially contaminated to different antibiotic levels. Cephalexin concentrations and the pH values were measured all along the process. It was found that cephalexin was transferred less into the cheese curd (1.8-4.3 % of the original amount) than into the whey (29.3-42.8 %). According to the results the concentration of cephalexin did not influence substantially the pH changes during curding nor the activity of the starter culture. However, pH of the fresh cheese showed significant (p < 0.05) differences compared to the control suggesting that antibiotic residues even below MRL level may influence the quality of product

Presence of Campylobacter and Salmonella spp. in Poultry and Environmental Samples from Farm to Retail in Hungary

The aim of this study was to investigate the occurrence of Salmonella enterica and its most important serovars Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, and Campylobacter spp. in the broiler meat production chain. Altogether 110 pooled samples were analysed; environment, cloaca, body surface at the farm, then carcass, offal, and packed meat from the slaughterhouse. The combination of redox potential measurement and realtime PCR was used for the detection of the microbes. At the farm, the first Salmonella positive result came from the water system, then it appeared in most of the samples. In contrast to the absence of Salmonella on the birds’ body surface before transportation, by the end of the processing it had reached 100%, with the only identifiable serovar being S. Infantis (65%). All packed meat samples showed positivity, from which 70% was S. Infantis. Campylobacter appeared at the farm on the 3rd week and remained significant during the breeding. After the slaughtering process, the contamination was 100% in the carcass, offal, and packaged meat samples. Our results demonstrated the success of the Salmonella control program, by the low prevalence of S. Typhimurium and Enteritidis

Rapid detection of Listeria monocytogenes in raw milk and soft cheese by a redox potential measurement based method combined with real-time PCR

The incidence of outbreaks of foodborne listeriosis has indicated the need for a reliable and rapid detection of the microbe in different foodstuffs. A method combining redox potential measurement and real-time polymerase chain reaction (PCR) was developed to detect Listeria monocytogenes in artificially contaminated raw milk and soft cheese. Food samples of 25 g or 25 ml were homogenised in 225 ml of Listeria Enrichment Broth (LEB) with Oxford supplement, and the redox potential measurement technique was applied. For Listeria species the measuring time was maximum 34 h. The absence of L. monocytogenes could reliably be proven by the redox potential measurement method, but Listeria innocua and Bacillus subtilis could not be differentiated from L. monocytogenes on the basis of the redox curves. The presence of L. monocytogenes had to be confirmed by real-time PCR. The combination of these two methods proved to detect < 10 cfu/g of L. monocytogenes in a cost- and time-effective manner. This method can potentially be used as an alternative to the standard nutrient method for the rapid detection of L. monocytogenes in food

Rapid detection of Salmonella in food by redox-potential measurement based method combined with real-time PCR

The classical ISO (2002) standard as reference method and the combination of redox potential measurement with real-time PCR technique were applied to detect Salmonella in milk, egg, broiler meat, and artificially contaminated egg samples. Food samples of 25 g were homogenized in 225 ml of RVS broth to prepare the basic suspension of the comparative tests. In the combined method the redox potential measurement technique serves as the selective enrichment system of the real-time PCR equipment. The reliable screening of Salmonella-free, negative samples by the redox potential measurement technique needed only 24 h. These negative samples determined by the PCR and the classical standard method in all cases proved to be negative as well. In case of positive redox result the Salmonella from the enriched suspension of the redox test-cell was identified by real-time PCR in 3 hours, instead of the conventional biochemical identification. Comparing our protocol to the ISO (2002) standard method, the total detection time of Salmonella presence/absence was less than 24 h contrary to the 114 h of the conventional method

Studies on the toxic interaction between monensin and tiamulin in rats: effects on P450 activities

Studies were carried out to investigate the effects of monensin and tiamulin, and the simultaneous administration of both compounds on microsomal enzymes in rats. In Phase I of the experiments the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively), while in Phase II the two compounds were administered simultaneously (monensin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). When monensin was administered by itself, it exerted no significant effect on microsomal liver enzymes. In a few cases, slight inhibition of certain enzyme activities was seen. Tiamulin provoked a dose-dependent hepatic enzyme induction. The combined administration of monensin and tiamulin at low doses (10 and 40 mg/kg, respectively) resulted in marked elevation of P450-related enzyme activities. The enzyme induction was more pronounced in females than in males. The results suggest that the simultaneous administration of tiamulin may influence the biotransformation of monensin, possibly increasing the amount of reactive metabolite(s) of the ionophore antibiotic

Pharmacokinetics and bioavailability of doxycycline in fasted and nonfasted broiler chickens

The pharmacokinetics and the influence of food on the kinetic profile and bioavailability of doxycycline was studied after a single intravenous (i.v.) and oral dose of 10.0 mg/kg body weight in 7-week-old broiler chickens. Following i.v. administration the drug was rapidly distributed in the body with a distribution half-life of 0.21 ± 0.01 h. The elimination half-life of 6.78 ± 0.06 h was relatively long and resulted from both a low total body clearance of 0.139 ± 0.007 L/h·kg and a large volume of distribution of 1.36 ± 0.06 L/kg. After oral administration to fasted chickens, the absorption of doxycycline was quite fast and substantial as shown by the absorption half-life of 0.39 ± 0.03 h, the maximal plasma concentration of 4.47 ± 0.16 —g/mL and the time to reach the Cmax of 1.73 ± 0.06 h. The distribution and the final elimination of the drug were slower than after i.v. administration. The absolute bioavailability was 73.4 ± 2.5%. The presence of food in the intestinal tract reduced and extended the absorption (t1/2a = 1.23 ± 0.21 h; Cmax = 3.07 ± 0.23 µg/mL; tmax = 3.34 ± 0.21 h). The absolute bioavailability was reduced to 61.1% ± 4.4%

Rapid in-house detection method of Campylobacter spp. from food by redox potential monitoring combined with real-time PCR

The rapid detection of Campylobacter spp. is of utmost importance for the reduction of infections in humans by contaminated food products. The standard culturing method (ISO 10272-1:2006) involves a high time and labour demand. In this paper, we present a method that reduces the detection time of Campylobacter spp. to or below one third as compared to the ISO method, at a reduced cost per test. We used redox potential change of enrichment cultures (Bolton broth with Bolton selective supplement) for reliably selecting Campylobacter-contaminated raw milk and broiler meat samples. Identification of Campylobacter spp. in the contaminated samples was done by real-time PCR method. Culturing time to conclusive redox monitoring varied between 6 and 24 h for positive samples, depending on the contamination rate, in contrast to 136 h with the standard culturing process. However, now the Campylobacter-negative majority of food samples will not need to be tested by real-time PCR because redox potential monitoring can identify them in the selective enrichment phase. This method could be potentially used as a faster alternative to the current standard ISO 10272-1:2006, for nonregulatory monitoring purposes

Farm to table: Residues of different pesticides in tomato and tomato juice – Food safety aspects

During plant cultivation, the pesticides can get into the tissue of vegetables due to crop protection processes, and thus into the food chain. Therefore, they constitute a potential risk to the consumer's health. Depletion of pesticides [spirotetramat (Movento), azoxystrobin and difenoconazole (Amistar Top)] was monitored by testing tomatoes treated individually or simultaneously and tomato juices prepared from the treated tomatoes. The investigations aimed to reveal any kinetic interaction between the compounds tested and changes in their elimination, and thus to assess their compliance with the official Maximum Residue Limits (MRLs). The co-presence of pesticides prolonged the elimination of the individual compounds which reached significantly higher residue levels ( P < 0.0001) in tomato, especially difenoconazole (45%) and azoxystrobin (50%) on day 8 after treatment that can cause food safety issues to the human consumers. However, the concentrations of pesticides applied alone or simultaneously were found to be below the corresponding MRL values after the withdrawal period in all investigated tomato and tomato juice samples. Accordingly, the investigated pesticides can be safely used simultaneously, their concentrations are in compliance with the legal regulations and thus their concomitant presence does not pose any risk to the consumers' health