scholarly journals Application of the Micro Biological Survey analytical method for the determination of bacterial load in cow raw milk

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Alessandra Cornacchia ◽  
Maria Antonietta Saletti ◽  
Violeta Di Marzio ◽  
Romolo Salini ◽  
Cristina Marfoglia ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Bacterial Load ◽  
Colorimetric Method ◽  
Independent Set ◽  
Raw Milk ◽  
Plate Count ◽  
Experimental Conditions ◽  
Biological Survey ◽  
Plate Count Method

The aim of this study was to evaluate the performance of “Micro Biological Survey – MBS Test” in the enumeration of bacterial load in cow raw milk. The MBS test is based on a colorimetric method recently developed and patented by “Roma Tre” University, Italy. The evaluation of the performance of the MBS method was carried out by comparison with plate count at 30°C (gold standard) and flow cytometry. Thirteen independent set of experiments were performed analyzing a total of 104 samples of cow raw milk with the selected methods. Results obtained using the MBS method are comparable with those obtained with the plate count method at 30°C (CFU/mL) and flow cytometry technology; in particular, the results obtained with the MBS method are very close to plate count’s at 30°C. On the other hand, there are statistically significant differences between these two methods’ and flow cytometry technology’s results that could be due to the different experimental conditions.

Correlation study between standard plate count and flow cytometry for determination of raw milk total bacterial count

2007 ◽  
Vol 60 (1) ◽  
pp. 44-48 ◽  
Author(s):  
LAERTE DAGHER CASSOLI ◽  
PAULO FERNANDO MACHADO ◽  
ANA CAROLINA DE OLIVEIRA RODRIGUES ◽  
ARLEI COLDEBELLA
Keyword(s):  
Flow Cytometry ◽  
Bacterial Count ◽  
Raw Milk ◽  
Correlation Study ◽  
Plate Count ◽  
Total Bacterial Count ◽  
Standard Plate Count ◽  
Standard Plate

scholarly journals Rapid Microbiological Assessment in Raw Milk: Validation of a Rapid Alternative Method for the Assessment of Microbiological Quality in Raw Milk

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1186
Author(s):  
Nicla Marri ◽  
Francesca Losito ◽  
Loris Le Boffe ◽  
Gilberto Giangolini ◽  
Simonetta Amatiste ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Bacterial Count ◽  
Raw Milk ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Biological Survey ◽  
Alternative Method ◽  
Colony Forming Units ◽  
Plate Count Method

The consumption of dairy products and the dairy industry are one of the main global agri-food sectors for its size, economic importance, and level of technology. Microbiological quality of pasteurized milk or other milk products is dependent on microbiological quality of raw milk. A variety of microbiological count methods is available for monitoring the hygienic quality of raw milk. Among them, the pour plate method is the official essay for counting the number of colony-forming units in milk samples according to International Organization for Standardization (ISO) No. 4833-1:2013. The aim of the present study is the validation of the Micro Biological Survey (MBS) method, against the reference plate-count method, for the assessment of the microbiological quality of raw milk. This comparative study, performed in collaboration with the Istituto Zooprofilattico Sperimentale del Lazio e della Toscana M. Aleandri (IZSLT), demonstrates the accuracy of this alternative method for the determination of total viable bacterial count in cow’s raw milk. The results obtained with the MBS method highlight its potential as a valid tool for reliable microbiological analysis in dairy industries.

scholarly journals Life, Death, and In-Between: Meanings and Methods in Microbiology

2011 ◽  
Vol 77 (16) ◽  
pp. 5571-5576 ◽  
Author(s):  
Hazel M. Davey
Keyword(s):  
Flow Cytometry ◽  
Image Analysis ◽  
Plate Count ◽  
Testing Methods ◽  
Viability Testing ◽  
Viability Staining ◽  
Microbial Viability ◽  
Plate Count Method ◽  
Viability Determination

ABSTRACTDetermination of microbial viability by the plate count method is routine in microbiology laboratories worldwide. However, limitations of the technique, particularly with respect to environmental microorganisms, are widely recognized. Many alternatives based upon viability staining have been proposed, and these are often combined with techniques such as image analysis and flow cytometry. The plethora of choices, however, adds to confusion when selecting a method. Commercial staining kits aim to simplify the performance of microbial viability determination but often still need adaptation to the specific organism of interest and/or the instruments available to the researcher. This review explores the meaning of microbial viability and offers guidance in the selection and interpretation of viability testing methods.

scholarly journals Rapid Microbiological Assessment in Raw Milk. Validation of a Rapid Alternative Method for the Assessment of Microbiological Quality in Raw Milk.

2020 ◽  
Author(s):  
Nicla Marri ◽  
Francesca Losito ◽  
Loris Le Boffe ◽  
Gilberto Giangolini ◽  
Simonetta Amatiste ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Bacterial Count ◽  
Raw Milk ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Biological Survey ◽  
Alternative Method ◽  
Colony Forming Units ◽  
Plate Count Method

The consumption of dairy products and the dairy industry is one of the main global agro-food sectors for size, economic importance and level of technology. Microbiological quality of pasteurized milk or other milk products is dependent on microbiological quality of raw milk. A variety of microbiological count methods is available for monitoring the hygienic quality of raw milk. Among them, the pour plate method is the official essay for counting the number of colony forming units in milk samples according to ISO 4833-1:2013. The aim of the present study is the validation of the Micro Biological Survey (MBS) method, against the reference plate count method, for the assessment of the microbiological quality of raw milk. This comparative study, performed in collaboration with the “Istituto Zooprofilattico Sperimentale del Lazio e della Toscana M. Aleandri” (IZSLT), demonstrates the accuracy of this alternative method for the determination of total viable bacterial count in cow’s raw milk. The results obtained with the MBS method highlighting its potential as a valid tool for reliable microbiological analysis in dairy industries.

Determination of Viable Bacterial Populations in Raw Milk within 20 Minutes by Using a Direct Epifluorescent Filter Technique

1997 ◽  
Vol 60 (7) ◽  
pp. 874-876 ◽  
Author(s):  
CLAUDE P. CHAMPAGNE ◽  
NANCY J. GARDNER ◽  
JULIE FONTAINE ◽  
JACQUES RICHARD
Keyword(s):  
Raw Milk ◽  
Plate Count ◽  
Bacterial Populations ◽  
Filter Technique ◽  
Milk Samples ◽  
Standard Plate ◽  
Plate Counts ◽  
Direct Epifluorescent Filter Technique ◽  
Triton X

The results from a shortened procedure for the direct epifluorescent filter technique (DEFT) determination of viable bacterial populations in raw milk were compared to standard plate counts. Shortening the prefiltration trypsin-Triton X-100 incubation period from 10 to 3 min enabled the completion of the analysis within 20 min. The short DEFT method results had a correlation coefficient (r) of 0.81 with plate counts. With respect to precision, the average difference between values of duplicate plate count analyses was 0.16 log units; that of the short DEFT was 0.14 log units. The slopes of the regressions equations were less than 1, indicating that a direct correlation is not achieved. Short DEFT values were 0.17 log units higher than those of plate counts on milk samples containing less than 10,000 CFU/ml. For milk samples containing counts over 10,000 CFU/ml, short DEFT values averaged only 0.05 log units above plate count readings. Daily preparation of the stain appears unnecessary since acridine orange solutions stored for up to 2 days at 4°C did not produce results significantly (P > 0.05) different from those obtained with fresh solutions. The short DEFT method has potential for the assessment of the bacteriological quality of raw milk in tanker deliveries.

Impedance Measurement as an Alternative to the Plate Count Method for Estimating the Total Count of Bacteria in Raw Milk

1987 ◽  
Vol 50 (8) ◽  
pp. 665-668 ◽  
Author(s):  
F. F. J. NIEUWENHOF ◽  
J. D. HOOLWERF
Keyword(s):  
Standard Deviation ◽  
Microbiological Quality ◽  
Impedance Measurement ◽  
Raw Milk ◽  
Plate Count ◽  
Impedance Method ◽  
Count Method ◽  
Plate Counts ◽  
Plate Count Method

An improved impedance method is described with a good standard deviation of repeatability (sm = 0.05 log unit) and a fair standard deviation of the estimate of the plate count from the detection time [(sy)x = 0.33 log unit]. Compared with the standard deviation of repeatability of the plate count method (0.07 log unit), the standard deviation of repeatability of the impedance method described is a significant improvement. The impedimetric experiments were done with a Bactometer M123. The detection times as measured by this instrument were compared with the plate counts at 30°C for samples of raw refrigerated farm milk. With this technique a good indication of the microbiological quality of raw milk can be obtained within 15 h.

EFFECT OF TEMPERATURE AND TIME OF PLATE INCUBATION ON THE ENUMERATION OF PASTEURIZATION-RESISTANT BACTERIA IN MILK1

1963 ◽  
Vol 26 (11) ◽  
pp. 357-363 ◽  
Author(s):  
W. R. Thomas ◽  
G. W. Reinbold ◽  
F. E. Nelson
Keyword(s):  
Incubation Temperature ◽  
Bacterial Count ◽  
Raw Milk ◽  
Effect Of Temperature ◽  
Plate Count ◽  
Resistant Bacteria ◽  
Pasteurized Milk ◽  
Standard Plate Count ◽  
Standard Plate

This study was undertaken to determine the effect of temperature and time of plate incubation upon the count of thermoduric bacteria in milk. Specific types of thermoduric bacteria in pure culture, as well as those present in the mixed flora of commercial milk samples, were enumerated. Plate incubation at 28 C for 4 days was the temperature-time combination that produced the highest thermoduric bacterial count with laboratory-pasteurized milk. Incubation at 21, 32 or 35 C gave lower counts. Thermoduric bacteria subjected to pasteurization were more exacting in their growth temperature requirements than were unheated bacteria. Cultures of Arthrobacter sp., Micrococcus varians and Streptococcus sp. grew over a much wider temperature range before laboratory pasteurization than after the heat treatment. The incubation temperature and time currently recommended for the standard plate count, while presumably adequate for the enumeration of bacteria in raw milk, may not be equally satisfactory for the determination of the maximum viable bacterial population of pasteurized milk.

scholarly journals A Flow Cytometry Method for Rapid Detection and Enumeration of Total Bacteria in Milk

2000 ◽  
Vol 66 (3) ◽  
pp. 1228-1232 ◽  
Author(s):  
Thusitha S. Gunasekera ◽  
Paul V. Attfield ◽  
Duncan A. Veal
Keyword(s):  
Flow Cytometry ◽  
Milk Proteins ◽  
Raw Milk ◽  
Plate Count ◽  
Standard Plate Count ◽  
Heat Treated ◽  
Standard Plate ◽  
Microbial Analysis ◽  
Total Bacteria ◽  
Microscopic Counting

ABSTRACT Application of flow cytometry (FCM) to microbial analysis of milk is hampered by the presence of milk proteins and lipid particles. Here we report on the development of a rapid (≤1-h) FCM assay based on enzymatic clearing of milk to determine total bacteria in milk. When bacteria were added to ultra-heat-treated milk, a good correlation (r ≥ 0.98) between the FCM assay and the more conventional methods of plating and direct microscopic counting was achieved. Raw milk data showed a significant correlation (P < 0.01) and a good agreement (r = 0.91) between FCM and standard plate count methods. The detection limit of the FCM assay was ≤104 bacteria ml of milk−1. This limit is below the level of detection required to satisfy legislation in many countries and states.

scholarly journals Enzymatic Activity as a Measure of Total Microbial Activity on Historical Stone

Heritage ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 671-681
Author(s):  
Elif Sırt Çıplak ◽  
Kiraz Göze Akoğlu
Keyword(s):  
Enzymatic Activity ◽  
Microbial Activity ◽  
Plate Count ◽  
Biological Factors ◽  
Bacterial Counts ◽  
Hydrolysis Method ◽  
Deterioration Process ◽  
Plate Count Method ◽  
Fda Hydrolysis

Stones of historical monuments exposed to the open air deteriorate over the course of time depending on physical, chemical, and biological factors acting in co-association. Among the biological factors, microorganisms play a key role in the deterioration process of stones. Detecting the level of microbial activity on stones is an essential step in diagnostic and monitoring studies of stone biodeterioration, and aids in controlling the performance of treatments applied to the stones. Therefore, this study aimed to develop a practical and rapid method for the determination of microbial activity on historical stones and use this method on the Mount Nemrut monuments (MNMs) (Adiyaman, Turkey). For that purpose, the fluorescein diacetate (FDA) hydrolysis method, frequently employed for soil environments, was adapted for the estimation and assessment of total microbial activity to understand whether microorganisms posed a potential risk for the biodeterioration of the limestones and sandstones of the MNMs. The traditional plate count method was also applied simultaneously to the same stone samples to compare and assist in the interpretation of the results of the FDA hydrolysis method, which relies on the quantitative determination of bacterial and fungal colonies in nutrient agar and malt extract agar medium, respectively. The results of the FDA hydrolysis and plate count methods showed consistency. The total microbial activity determined by the FDA hydrolysis method was low for both types of stone samples. In addition, the plate count method showed low bacterial and fungal counts on all of the samples. This revealed that microbial activity did not play an important role in the stone deterioration process on the MNMs, although different lichen species were frequently observed on both the sandstones and the limestones. Hence, further investigation must be undertaken for determination of their long-term behavior and effects on the stones of the MNMs. On the other hand, the results of the FDA hydrolysis and plate count methods showed correlation. Lower bacterial counts were observed when lower enzymatic activity was observed in the stone samples, and likewise, higher bacterial counts were observed when higher enzymatic activity was observed. Consequently, the application of the FDA hydrolysis method was determined to be reliable for the estimation of total microbial activity on historical stones. The method had obvious advantages in terms of its rapid measurement rate and sensitivity, even on small samples.

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