Search Results

You are looking at 1 - 10 of 21 items for

  • Author: Krzysztof Kwiatek x
Clear All Modify Search
Open access

Joanna Stadnik, Małgorzata Karwowska, Zbigniew Dolatowski, Małgorzata Świątkiewicz and Krzysztof Kwiatek

Effect of Genetically Modified Feeds on Physico-Chemical Properties of Pork

The objective of this study was to evaluate the effects of genetically modified (GM), insect-resistant Bt maize (MON810) and the meal made of glyphosate-tolerant soybean (Roundup Ready MON40-3-2) used as the dietary components for pigs on the physico-chemical properties of meat. Forty-eight fatteners derived from Polish Landrace x Polish Large White sows mated to a Duroc x Pietrain boar were used. All animals received isonitrogenous and isoenergetic diets containing or not containing the genetically modified components. The design of the experiment was as follows: group I (control) - non-modified soybean meal and maize; group II - GM soybean meal and non-modified maize; group III - non-modified soybean meal and GM maize; group IV - GM soybean meal and GM maize. The examination of the pH values of loin and neck muscles indicated no statistically significant differences between pigs fed diets containing non-transgenic or transgenic feeds. No statistical differences were observed for water holding capacity (WHC) within dietary treatments. The introduction of transgenic maize and soybean meal into pig diets did not significantly affect the a* colour parameter of loin as well as neck muscles. The use of transgenic maize or soybean meal did not cause significant changes in the L* colour value of loin. Results obtained for neck muscles were more differentiated, possibly due to the natural heterogeneity of this primal cut. Pigs which had consumed the transgenic diet exhibited slightly decreased lipid stability of loin, as indicated by thiobarbituric acid reactive substances (TBARS). The decrease was statistically significant only in the case of muscles from group II. The addition of feeds derived from genetically modified crops into pig diets did not significantly affect the stability of neck muscle lipids; however, TBARS values of these muscles were twice those of loin muscles.

Open access

Ewelina Patyra and Krzysztof Kwiatek

Abstract

Introduction: The article presents a rapid and simple analytical procedure for determination of four tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in animal medicated feedingstuffs. Material and Methods: Two-gramme samples were extracted by a Na2EDTA-McIlvaine buffer (pH 4)/methanol mixtures (40/60, v/v). The determination was achieved by liquid chromatography using a Zorbax Eclipse XDB C18 analytical column with mass spectrometer detection (LC-MS). Results: Recoveries of the antibiotics from spiked feed samples ranged from 78.2% to 113.5%. The LOD and LOQ for tetracyclines in feeds ranged from 2.8 to 4.2 and from 4.3 to 5.7 mg/kg, respectively. Conclusion: The method was successfully validated and proved to be efficient, precise, and useful for quantification of tetracyclines in medicated feedingstuffs.

Open access

Ewelina Kowalczyk and Krzysztof Kwiatek

Abstract

Introduction: Pyrrolizidine alkaloids (PAs) are probably the most widespread toxins of natural origin. More than 6,000 plant species produce these toxic compounds. Bees can forage on flowers of plants producing PAs, which leads to contamination of honey with the toxic compounds. To determine the contamination of honey with PAs, a sensitive method based on liquid chromatography coupled with mass spectrometry has been developed.

Material and Methods: PAs were extracted with 0.05 M sulphuric acid and purified with MCX cartridges. A solvent mixture consisting of ethyl acetate, methanol, acetonitrile, ammonia, and triethylamine (8:1:1:0.1:0.1, v/v) was used to wash alkaloids from the cartridges. After evaporation the residues were reconstituted in water and methanol mixture and subjected to LC–MS analysis.

Results: The developed method was validated according to SANTE/11945/2015 requirements. The recovery was from 80.6% to 114.5%. The repeatability ranged from 2.3% to 14.6%, and the reproducibility was from 4.9% to 17.7%.

Conclusions: A new method for the determination of PAs in honey has been developed and validated. All evaluated parameters were in accordance with the SANTE/11945/2015 guidance document. Out of 50 analysed honey samples, 16 (32%) were positive for the content of at least one PA.

Open access

Ewelina Kowalczyk and Krzysztof Kwiatek

Abstract

Introduction: Pyrrolizidine alkaloids (PAs) are secondary metabolites produced by many plant species. Due to their toxicity PAs can pose a risk to human and animal health. To detect the toxic compounds in feed materials a sensitive method based on liquid chromatography coupled with mass spectrometry has been developed.

Material and Methods: PAs were extracted with sulphuric acid and purified with cation exchange cartridges. A newly developed solvent mixture consisting of ethyl acetate, methanol, acetonitrile, ammonia, and triethylamine was used to wash alkaloids from the cartridges. After evaporation the residues were reconstituted in water and methanol mixture and subjected to LC-MS analysis.

Results: The developed method was validated according to SANTE/11945/2015 guidelines. The recovery was from 84.1% to 112.9%, the repeatability ranged from 3.0% to 13.6%, and the reproducibility was from 4.8% to 18.9%.

Conclusions: A sensitive and selective method for determination of PAs in feed materials has been developed and validated. All evaluated validation parameters were in accordance with EU Reference Laboratories document no. SANTE/11945/2015. Almost 41% of the analysed feed samples were positive for the presence of at least one PA.

Open access

Elżbieta Kukier, Magdalena Goldsztejn, Tomasz Grenda, Krzysztof Kwiatek, Dariusz Wasyl and Andrzej Hoszowski

Abstract

The aim of the study was the assessment of microbiological quality of compound feed used in Poland in 2007-2010. The examinations were done at all veterinary diagnostic laboratories operating in the frame of official laboratory system. The occurrence of Salmonella sp. and counts of Enterobacteriaceae family, mesophilic aerobic bacteria, total microorganisms, and fungi were assessed. Assays were done following Polish, European, and international standards. Percentage of contamination of compound feed for poultry, pigs, and cattle by Salmonella sp. ranged from 0% to 3.5%. The highest contamination level by Enterobacteriaceae bacteria were detected in wet petfood. No more than 106 cfu/g of aerobic bacteria and no more than 105 cfu/g of fungi were detected in the feed. The results of the study revealed that the microbiological quality of compound feed used in Poland in 2007-2010 was better than the quality of the feed used in 2003-2006.

Open access

Tomasz Grenda, Elżbieta Kukier, Magdalena Goldsztejn and Krzysztof Kwiatek

Abstract

A PCR-based procedure for detection of C. botulinum C and D in corn silage samples was validated. During the validation, method specificity, sensitivity, and accuracy were determined according to PN - EN ISO 16140:2004. Additionally, the specificity of the validated methods was proved by sequence analysis of PCR products obtained from examination of samples connected with botulism cases in cattle and mallard ducks. Limit of detection was estimated according to the Spearman - Kärber formula and expressed as LOD50. The obtained results showed that a 100% specificity was achieved. The sequencing of PCR products revealed 99% identity with sequences of bont/C and bont/D genes deposited in the GenBank. The sensitivity value ranged from 63.3% for C. botulinum type C to 75% for type D. The accuracy value varied from 72% for type C to 81.3% for type D. LOD50 was estimated at the levels of 0.272 (0. D 188-0395) spore/g for type C and 0.17 (0.1-0.289) spore/g for type D. The described PCR-based procedure enabled detection of C. botulinum C and D at the stage of liquid culture. This makes examination of feed samples possible without isolation process. The presented procedure could support the diagnosis of botulism by faster and specific laboratory examination process.

Open access

Ewelina Patyra, Ewelina Kowalczyk and Krzysztof Kwiatek

Abstract

A chromatographic procedure for determination of oxytetracycline (OXT), tetracycline (TC), chlorotetracycline (CTC), and doxycycline (DC) in water samples was developed and was applied for the analysis of water samples collected from poultry and pig farms and environmental water samples. Samples were acidified with trifluoroacetetic acid to pH 3 and further purified by solid phase extraction using Oasis HLB cartridges. The samples were dried up and redissolved in the mixture of oxalic acid and methanol. Separation was performed on reserved phase column (Phenomenex column C18 , 250 mm × 4.6 mm, 5 μm) by multistep gradient elution, and detection was carried out at 360 nm for OTC and TC, 370 nm for CTC, and 350 nm for DC. The tetracyclines were eluted with the mobile phase of 0.05 M oxalic acid (pH 2.5), acetonitrile, and methanol. This method provided average recoveries of 83.53% to 108.59%, with coefficient of variations (CVs) of 2.41% to 8.64% in the range of 10 to 1000 μg/L OTC, TC, CTC, and DC in water. The linearity for the tetracyclines was determined by HPLC-DAD in the range 10 to 1000 μg/L, with the correlation coefficient (R) > 0.99. The LOD and LOQ for the tetracyclines in water samples ranged from 1.51 to 4.00 and 2.51 to 5.93 μg/L, respectively.

Open access

Tomasz Grenda, Elżbieta Kukier, Zbigniew Sieradzki, Magdalena Goldsztejn and Krzysztof Kwiatek

Abstract

The aim of this study was to perform an in-house validation of multiplex PCR method for C. botulinum detection in food and feed samples. The study was carried out on food and feed matrixes artificially contaminated by spores of C. botulinum reference strains. The following characteristic parameters for qualitative detection were estimated: limit of detection expressed as LOD50 according to the Spearman-Kärber formula, specificity, sensitivity, and accuracy according to the PN-EN ISO 16140:2004. The validated method showed high specificity. Specific PCR products were revealed only for DNA obtained from samples contaminated with C. botulinum spores. PCR inhibition was observed, especially during examination of contaminated feed. The calculated LOD50 for feed was nearly 10 times higher than for food. The implemented method enables to obtain test results during 3 d without time- consuming process of isolation and proving the ability of strains to produce botulinum toxins.

Open access

Elżbieta Kukier, Magdalena Goldsztejn, Tomasz Grenda and Krzysztof Kwiatek

Abstract

Clostridium perfringens isolates were obtained from pigs of five porcine farms in Poland. The presence of C. perfringens was detected in 92% of faeces samples and its number ranged from 1.0 x 101 cfu/g to 1.2 x 107 cfu/g. All the isolates belonged to type A and 48.7% of them contained cpb2 gene. The qualitative assessment of toxin genes expression by type A subtype β2 isolates showed expression of cpa gene in 100% of strains and cpb2 gene in 71% of the analysed strains. The isolate from one-day-old piglets demonstrated also the expression of cpa and cpb2 genes.

Open access

Elżbieta Kukier, Magdalena Goldsztejn, Tomasz Grenda, Krzysztof Kwiatek and Łukasz Bocian

Abstract

The study was conducted at all regional veterinary diagnostic laboratories. Feed materials were examined for Salmonella prevalence and contamination by Enterobacteriaceae, aerobic mesophilic bacteria, total plate count, fungi, Clostridium sp., and Bacillus cereus. Assays were done following international and Polish standards used in food and feed microbiology. Salmonella sp. were most often detected in oil seeds. In most of the examined feed ingredients, the number of Enterobacteriaceae did not exceed 10 cfu/g. The contamination by aerobic bacteria ranged most often from 101to 107 cfu/g, and the highest mycological contamination was noted in cereal grains (108 cfu/g). The results showed that microbial contamination of feed materials in regard to Enterobacteriaceae, fungi, and total plate counts declined over the past years.