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 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%

Pulse and continuous oral norfloxacin treatment of experimentally induced Escherichia coli infection in broiler chicks and turkey poults

Experimental colibacillosis was produced in 40 healthy, 7-day-old broiler chickens and turkeys by intratracheal injection of 1 × 108 CFU/chick and 1.23 × 109 CFU/poult bacteria of an O1:F11 strain of Escherichia coli, respectively. Two days before E. coli challenge all chicks were vaccinated with a live attenuated strain of infectious bronchitis virus (H-52). This model of infection - at least in chicken - proved to be useful for evaluating the efficacy of antimicrobial medication, by recording mortality, body weight gain, pathological alterations and frequency of reisolation of E. coli. Using this model, the efficacy of two different dosing methods of norfloxacin (continuous and pulse dosing) was evaluated. The once-per-day pulse dosing of norfloxacin administered via the drinking water at 15 mg/kg body weight proved to be more efficacious than the continuous dosing method of 100 mg/L for 5 days in chickens, while there were no convincing differences between the two treatment regimens in turkeys. The results confirmed earlier observations on the pharmacokinetic properties of norfloxacin in chicks and turkeys (Laczay et al., 1998)

Application of the redox potential measurementbased rapid method in the microbial hygienic control

The standard culture methods in food hygiene used for the determination of microbial count are slow. In order to shorten the duration of detection of sampled bacteria, the Authors elaborated a redox potential measurement-based new method. The applicability of the new method was compared to the standard swab method in the framework of interlaboratory proficiency test aimed to determine the microbial contamination of model surfaces and in the hygienic control of a food manufacturing pilot plant. The comparative evaluation of total counts and Enterobacterium counts obtained by standard plate pouring and by the new method proved that there is no significant difference between the results of the two procedures. The total count determination with the new method lasted only 10–16 h in contrast to 72 h of plate counting. Particular advantages of the new method are that the bacterial count of the swab can be determined directly, without any washing down of the microbes from the swab and due to the different shapes of the redox curves, the total count and enterobacteria could be enumerated simultaneously from the same nonselective nutrient broth