ABSTRACT
During the spring of 1996 and autumn of 1997 unusual mortality outbreaks among rainbow trout fry and yearlings occurred at two different trout farms, resulting in mortality of 20 and 10 per cent, respectively. Generally, the affected fish, swimming at the water surface, were reluctant to eat and were dark pigmented with visible haemorrhages around and within the oral cavity. Bacterial isolates from moribund fish from both cases were identified as Yersinia ruckeri by standard biochemical tests and API 20E. The isolated strains were found to be sensitive to tetracycline, chloramphenicol, co-trimoxazole, nalidixic acid, flumequine, enrofloxacin, carbenicillin and gentamicin. Microplate agglutination assay confirmed that both isolates belonged to serotype O1. The pathogenicity of the isolated bacteria was confirmed by challenge experiment. Titres of specific antibodies were determined in the sera of survivors. The titre was highest on the 21st day postchallenge and was detectable until the 81st day.
Subject(s)
Disease Outbreaks/veterinary , Fish Diseases/epidemiology , Trout , Yersinia Infections/veterinary , Animals , Anti-Bacterial Agents/pharmacology , Croatia/epidemiology , Fish Diseases/etiology , Fish Diseases/mortality , Microbial Sensitivity Tests/veterinary , Serotyping/veterinary , Yersinia/classification , Yersinia/drug effects , Yersinia/isolation & purification , Yersinia/pathogenicity , Yersinia Infections/epidemiologyABSTRACT
The aim of this study was to assess the suitability of the perirenal fatty tissue for the determination of an organochlorine pesticide. Fatty tissue samples were prepared by the matrix solid phase dispersion (MSPD) method, and pesticide levels were determined by gas chromatography on capillary column using an electron capture detector. Results were confirmed by gas chromatography/mass spectrometry (GC/MS) system. The results showed that the perirenal fatty tissue contained significantly higher levels of hexachlorobenzene (HCB) than the dorsal fatty tissue (P < 0.01). All the levels were below the criteria for maximum residue limits established by Croatia and the EU.
Subject(s)
Adipose Tissue/chemistry , Fungicides, Industrial/analysis , Hexachlorobenzene/analysis , Pesticide Residues/analysis , Swine , Abattoirs , Animals , Food Analysis/methods , Food Contamination/analysis , Gas Chromatography-Mass Spectrometry/methods , Gas Chromatography-Mass Spectrometry/veterinary , Meat Products/analysisABSTRACT
During the analysis of chlorinated pesticides in animal fat tissue applying the matrix solid-phase dispersion method, and notwithstanding the use of a gas chromatograph with a highly selective capillary column, two peaks occur: one with a retention time very similar to that of lindane, and the other almost identical to that of dieldrin. Repeated analyses of the same sample with a GC/MS system revealed that neither lindane nor dieldrin were present. It was proven that those peaks resulted from florisil of local origin used for analysis, but not from the original Florisil. The removal of the first peak ("lindane") was possible through heating of florisil of local origin at 680 degrees C for 4 hours, whereas some other method would be required for the removal of the other peak ("dieldrin"). The incident proved that, in such demanding analyses, it is extremely important to use original, high quality substances to avoid possible interference and misinterpretation of results.
Subject(s)
Food Analysis , Hydrocarbons, Chlorinated , Insecticides/analysis , Magnesium Silicates/analysis , Pesticide Residues/analysis , Adipose Tissue/chemistry , Dairy Products/analysis , Food Analysis/methods , Meat/analysisABSTRACT
The concentration of quinoxaline-2-carboxylic acid (QCA) determined by HPLC after alkaline hydrolysis of liver and muscle of swine, ranged from < 3 ng/g to 45.3 ng/g in liver, and from < 3 ng/g to 10.8 ng/g in muscle samples. After the 77th day of therapy QCA was found in samples of liver (9.7 ng/g). Recoveries obtained for both liver and muscle were 70% at 5 ng/g, 77% and 75% respectively at 10 ng/g, and 90% for both liver and muscle at 30 ng/g. This experiment was performed within the frame of the National Monitoring Programme of Residues in Animal Tissues in the Republic of Croatia.
Subject(s)
Anti-Infective Agents/therapeutic use , Carbadox/therapeutic use , Liver/metabolism , Muscles/metabolism , Quinoxalines/pharmacokinetics , Animals , Chromatography, High Pressure Liquid , Quinoxalines/analysis , SwineABSTRACT
Total amounts of arsenic in foods sold in Croatia were determined over a 5-year period (1988-1993). Highest mean levels were recorded in the following food groups: fish (498 micrograms/kg), fishery products (270 micrograms/kg) and cheese and dairy products (39 micrograms/kg); lowest levels were contained in fruit, chocolate and fruit products (0.2, 0.2 and 0.3 microgram/kg, respectively). Mean weekly dietary arsenic intake estimated on the basis of the level of arsenic and consumption of the studied foodstuffs is 81.9 micrograms/individual. The PTWI level achieved by the general population of Croatia is 7.8%.
Subject(s)
Arsenic/administration & dosage , Food Contamination/analysis , Animals , Arsenic/analysis , Arsenic/toxicity , Croatia , Dairy Products , Environmental Pollutants/administration & dosage , Environmental Pollutants/analysis , Environmental Pollutants/toxicity , Fishes , Humans , Maximum Allowable ConcentrationABSTRACT
The level of lead and cadmium in foodstuffs in the Republic of Croatia was determined by the method of atomic absorption spectrophotometry from the beginning of 1988 to mid 1993. Mean weekly dietary intake of these toxic metals was then estimated on the basis of the level of contamination and consumption of the foodstuffs concerned. The results show that mean weekly dietary intake of lead is 701 micrograms/person and 121.4 micrograms cadmium/person. With respect to the provisional tolerable weekly intake (PTWI), these values are equal to 19.9% for lead and 24.4% for cadmium.
