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Leuschner RGK, Bew J, Cruz A, Adler A, Auclair E, Bertin G, Braconnier M, Domig K, Jones P, Kneifel W, Krause M, Marmo S, Michard J, Mietke H, O’Briain A, Olofson AS, Ruppitsch W, Thalmann A, Voets A, Warmerdam C. Enumeration of Probiotic Bacilli Spores in Animal Feed: Interlaboratory Study. J AOAC Int 2019. [DOI: 10.1093/jaoac/86.3.568] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80°C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (109 colony-forming units [CFU]/g) and low (105 CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the re-peatability relative standard deviation (RSDr) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSDr values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.
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Affiliation(s)
- Renata G K Leuschner
- Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK
| | - Jan Bew
- Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK
| | - Armando Cruz
- Gaiker, Parque Tecnologico, Edificio 202, 48170 Zamudio (Bizkaia), Spain
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Leuschner RGK, Bew J, Simpson PJ, Ross PR, Stanton C, Adler A, Bertin G, Braconnier M, Coeuret V, Domig K, Durand H, Kneifel W, Krause M, Marmo S, Michard J, Mietke H, Olofson AS, Thalmann A, Vernoux JP, Voets A, Warmerdam C. Enumeration of Probiotic Pediococci in Animal Feed: Interlaboratory Study. J AOAC Int 2019. [DOI: 10.1093/jaoac/86.4.791] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
An enumeration method to be used as official control under Council Directive 70/524/EEC for probiotic pediococci used as feed additives was validated for consideration for adoption as Comitée Européen de Normalisation (CEN) and ISO standards. Seventeen laboratories in 11 European countries carried out an interlaboratory study. A spread plate method following BS ISO 15214:1998 using 4 different agars [MRS, acidified MRS, MRS with triphenyl tetrazolium chloride (TTC), and a newly developed pediococci selective medium (PSM)] was validated. Precision data in terms of repeatability (r) and reproducibility (R) of the method for each medium using different feeding stuffs with a high and a low inoculation level were determined. Pediococci were present in the samples in mixtures with other probiotics. The enumeration of pediococci on all agars showedan RSDr value of 0.4–3.1% and an RSDR of 1.3–4.8%. MRS agar was preferred, followed by acidified MRS and MRS + TTC agar. All 4 media gave similar counts. Depending on the presence and concentration of other probiotic, such as enterococci, lactobacilli, and yeast, acidified MRS or MRS + TTC agar are recommended. The PSM was selective for pediococci and can be used if this species is present at a concentration more than 10-fold lower than other species that can grow on the MRS agars. The methodology with all 4 media is not applicable to mineral feed.
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Affiliation(s)
- Renata G K Leuschner
- Department for Environment, Food and Rural Affairs, Central Science Laboratory, Sand Hutton, York YO41 1LZ, United Kingdom
| | - Jan Bew
- Department for Environment, Food and Rural Affairs, Central Science Laboratory, Sand Hutton, York YO41 1LZ, United Kingdom
| | - Paul J Simpson
- National Dairy Products Research Centre, Moorepark, Fermoy, Ireland
| | - Paul R Ross
- National Dairy Products Research Centre, Moorepark, Fermoy, Ireland
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Björklund E, Pallaroni L, Holst CV, Unglaub W, Bosch J, Calderon-Alvarez F, Costa J, Cowles J, Gaede W, Krause M, Marmo S, Pecoraro S, Reaney S, Sutton M, Thiele D, Wolf C. Method of Determination of Appropriate Heat Treatment of Animal Meal by Immunoassay Developed for Detection of Cooked Beef: Interlaboratory Study. J AOAC Int 2019. [DOI: 10.1093/jaoac/84.6.1839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
An interlaboratory trial was conducted for the validation of an enzyme-linked immunosorbent assay (ELISA) method for determination of appropriate heat treatment of animal meal. A commercially available ELISA test kit developed for the identification of beef in cooked food was used in the study. Twelve laboratories from 7 European countries examined 2 different analytical protocols to establish the most appropriate analytical method. Three different samples were used, 2 animal waste materials sterilized at 129 and 134°C (wet conditions), respectively, and a meat and bone meal material processed at dry conditions (maximum temperature, 140°C). Statistical evaluation applying t-statistics showed that the animal meal treated according to European legislation (>133°C) was clearly distinguishable from the 2 other test materials at a 99% confidence level using both analytical protocols. This method can be considered as a complementary test to the immunoassay developed for the detection of pork in cooked food that is already applied in routine analysis for the surveillance of rendering plants.
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Affiliation(s)
- Erland Björklund
- European Commission, Joint Research Centre, Food Products and Consumer Goods Unit, I-21020 Ispra (VA), Italy
| | - Lea Pallaroni
- European Commission, Joint Research Centre, Food Products and Consumer Goods Unit, I-21020 Ispra (VA), Italy
| | - Christoph von Holst
- European Commission, Joint Research Centre, Food Products and Consumer Goods Unit, I-21020 Ispra (VA), Italy
| | - Wolfgang Unglaub
- Staatliches Tieraerztliches Untersuchungsamt Aulendorf, Centre for Diagnostic Baden-Wuerttemberg, Loewenbreitestrasse 18-20, D-88326 Aulendorf, Germany
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Rimhanen-Finne R, Vuorinen A, Marmo S, Malmberg S, Hänninen ML. Comparative analysis of Cryptosporidium, Giardia and indicator bacteria during sewage sludge hygienization in various composting processes. Lett Appl Microbiol 2004; 38:301-5. [PMID: 15214729 DOI: 10.1111/j.1472-765x.2004.01487.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS To evaluate the suitability of Clostridium perfringens, Escherichia coli and enterococci as indicator organisms for Cryptosporidium and Giardia in treated sludge. METHODS AND RESULTS Occurrence of Cryptosporidium oocysts and Giardia cysts, detected and enumerated by direct immunofluorescence microscopy, were compared with counts of indicator bacteria during six different sewage sludge hygienization processes, including closed reactor and open windrow composting, and sludge sanitation by quicklime or peat addition. No statistical correlation existed between the counts of indicator bacteria, Cl. perfringens, E. coli, and enterococci and occurrence of Cryptosporidium or Giardia. In sludge end-products, Giardia cysts were detected more frequently than Cryptosporidium oocysts. SIGNIFICANCE OF THE STUDY Direct analysis is the best method to confirm the presence of (oo)cysts in sludge.
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Affiliation(s)
- R Rimhanen-Finne
- Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
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Leuschner RGK, Bew J, Cruz A, Adler A, Auclair E, Bertin G, Braconnier M, Domig K, Jones P, Kneifel W, Krause M, Marmo S, Michard J, Mietke H, O'Briain A, Olofson AS, Ruppitsch W, Thalmann A, Voets A, Warmerdam C. Enumeration of probiotic bacilli spores in animal feed: interlaboratory study. J AOAC Int 2003; 86:568-75. [PMID: 12852578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80 degrees C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (10(9) colony-forming units [CFU]/g) and low (10(5) CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the repeatability relative standard deviation (RSD(r)) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSD(r) values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.
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Affiliation(s)
- Renata G K Leuschner
- Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK.
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