The relationship of flow cytometry results with classical measures of bacterial counts in raw refrigerated milk

Cassoli, Laerte Dagher; Francischetti, Graziela; Machado, Paulo Fernando; Mourão, Gerson Barreto

doi:10.1111/j.1471-0307.2010.00580.x

Cited by 4 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Azidiol (0.15% chloramphenicol and 3.6% sodium azide) was added to the aliquots for flow cytometry at a concentration of 160 μL per 50 mL of milk and submitted to flow cytometry quantification of the Staph. aureus ATCC 29213 (Cassoli et al, 2010). One bronopol tablet (8 mg of 2-bromo-2-nitropropane-1, 3-diol and 0.3 mg of natamycin each; Microtabs II, D&F Control Systems Inc., Norwood, MA) was added to the aliquot used for qPCR.…”

Section: Preparation Of Standards For the Qpcr Protocol And Reference Methodsmentioning

confidence: 99%

Detection and enumeration of Staphylococcus aureus from bovine milk samples by real-time polymerase chain reaction

Botaro¹,

Cortinhas

Março

et al. 2013

Journal of Dairy Science

View full text Add to dashboard Cite

The aim of this study was to develop and evaluate a real-time quantitative PCR (qPCR)-based method to detect and quantify Staphylococcus aureus in bronopol-preserved milk samples from subclinical intramammary infections (IMI). Serial dilutions of milk artificially inoculated with Staph. aureus ATCC 29213 were used to establish a standard curve (cfu/mL) of the qPCR assay targeting the Staph. aureus thermonuclease-encoding gene nuc according to the strain plate count. The analytical sensitivity, specificity, and repeatability of the qPCR assay were determined. A total of 60 milk samples, collected from mammary quarters without abnormal appearance and with positive isolation of Staph. aureus, were submitted to both the qPCR protocol and Staph. aureus plate counting and results from both methods were compared. Staphylococcus aureus from bronopol-preserved, subclinical IMI milk samples were not accurately enumerated by qPCR compared with plate counting of the nonpreserved, raw milk sample. The detection limit of the qPCR protocol of inoculated Staph. aureus ATCC 29213 in bronopol-preserved milk samples was 1.04 × 10(1) cfu/mL. The qPCR protocol can be a high-throughput and rapid diagnostic assay to accurately detect Staph. aureus IMI from bronopol-preserved milk samples compared with a traditional culturing method. However, the proposed qPCR protocol is not accurate for counting of Staph. aureus in bronopol-preserved milk samples from naturally infected mammary glands.

show abstract

Section: Preparation Of Standards For the Qpcr Protocol And Reference Methodsmentioning

confidence: 99%

Detection and enumeration of Staphylococcus aureus from bovine milk samples by real-time polymerase chain reaction

Botaro¹,

Cortinhas

Março

et al. 2013

Journal of Dairy Science

View full text Add to dashboard Cite

show abstract

“…Milking frequency can be increased in a manner that minimizes additional labour by employing unequal milking intervals (Hale et al, 2003). Total bacteriological count was in accordance with 39 % of the best samples of Cassoli et al (2010).…”

Section: Resultsmentioning

confidence: 98%

Dairy cow monitoring by RFID

Stankovski

Ostojić

Šenk

et al. 2012

Sci. agric. (Piracicaba, Braz.)

View full text Add to dashboard Cite

Dairy cows identification and monitoring on small cattle farms are usually based on the utilization of barcode technology. This kind of identification technology is unsuitable for dairy cows milking and feeding process automation. Radio Frequency Identification (RFID) technology is a better solution in this case. This paper describes the research and implementation of the milking cycle´s automated monitoring with the use of RFID tags conducted on a small cattle farm in the Republic of Serbia. This solution is based on RFID system which consists of two parts. First part includes control box, two Ultra High Frequency (UHF) RFID readers operating at frequency of 915 MHz and RFID tags glued onto the dairy cow ear labels. Second part includes software modules for acquisition and collecting data from RFID tags to build up an archive due to supervision and analysis of the milking cycle. Reading accuracy of RFID system in the observed period was 99.8 % in average. A group of dairy cows having a settled milking cycle within an interval of 12h ± 5 % had a 1.5 % better yield and a 0.08 better quality in comparison with a group of dairy cows having a milking cycle variance higher than 20 %. RFID system implemented in described way can be easily integrated into a new or existing farm management system in order to have better production results which depend on several factors including settled milking cycles.

show abstract

“…When the penalty cut-off point for the BsnFC was adjusted so that a similar proportion of milk samples incurred penalty as using the 50,000 cfu by SPC, the suggested BsnFC equivalent point was 320,000 ibc (Table 3). The BsnFC/SPC ratio in cow milk is normally about 3:1 (Cassoli et al, 2010) and this is explained by the counting of all bacteria cells singly by the BsnFC against counting colonies by the culture method (Suhren and Walte, 1998). However, the difference in counting principles does not explain the higher BsnFC/SPC ratio of 6:1 in goat milk for this study.…”

Section: Bactoscan Fc Equivalents For Cow and Goat Milksmentioning

confidence: 99%

Assessment of the application of an automated electronic milk analyzer for the enumeration of total bacteria in raw goat milk

Ramsahoi

Gao

Fabri

et al. 2011

Journal of Dairy Science

View full text Add to dashboard Cite

Automated electronic milk analyzers for rapid enumeration of total bacteria counts (TBC) are widely used for raw milk testing by many analytical laboratories worldwide. In Ontario, Canada, Bactoscan flow cytometry (BsnFC; Foss Electric, Hillerød, Denmark) is the official anchor method for TBC in raw cow milk. Penalties are levied at the BsnFC equivalent level of 50,000 cfu/mL, the standard plate count (SPC) regulatory limit. This study was conducted to assess the BsnFC for TBC in raw goat milk, to determine the mathematical relationship between the SPC and BsnFC methods, and to identify probable reasons for the difference in the SPC:BsnFC equivalents for goat and cow milks. Test procedures were conducted according to International Dairy Federation Bulletin guidelines. Approximately 115 farm bulk tank milk samples per month were tested for inhibitor residues, SPC, BsnFC, psychrotrophic bacteria count, composition (fat, protein, lactose, lactose and other solids, and freezing point), and somatic cell count from March 2009 to February 2010. Data analysis of the results for the samples tested indicated that the BsnFC method would be a good alternative to the SPC method, providing accurate and more precise results with a faster turnaround time. Although a linear regression model showed good correlation and prediction, tests for linearity indicated that the relationship was linear only beyond log 4.1 SPC. The logistic growth curve best modeled the relationship between the SPC and BsnFC for the entire sample population. The BsnFC equivalent to the SPC 50,000 cfu/mL regulatory limit was estimated to be 321,000 individual bacteria count (ibc)/mL. This estimate differs considerably from the BsnFC equivalent for cow milk (121,000 ibc/mL). Because of the low frequency of bulk tank milk pickups at goat farms, 78.5% of the samples had their oldest milking in the tank to be 6.5 to 9.0 d old when tested, compared with the cow milk samples, which had their oldest milking at 4 d old when tested. This may be one of the major factors contributing to the larger goat milk BsnFC equivalence. Correlations and interactions between various test results were also discussed to further understand differences between the 2 methods for goat and cow milks.

show abstract

The relationship of flow cytometry results with classical measures of bacterial counts in raw refrigerated milk

Cited by 4 publications

References 11 publications

Detection and enumeration of Staphylococcus aureus from bovine milk samples by real-time polymerase chain reaction

Detection and enumeration of Staphylococcus aureus from bovine milk samples by real-time polymerase chain reaction

Dairy cow monitoring by RFID

Assessment of the application of an automated electronic milk analyzer for the enumeration of total bacteria in raw goat milk

Contact Info

Product

Resources

About