Detection of Bacillus cereus Diarrheal Enterotoxin in Raw and Pasteurized Milk

1997 ◽  
Vol 60 (11) ◽  
pp. 1391-1394 ◽  
Author(s):  
JOSEPH A. ODUMERU ◽  
ANN K. TONER ◽  
C. ANNE MUCKLE ◽  
MANSEL W. GRIFFITHS ◽  
JOHN A. LYNCH
Keyword(s):  
Bacillus Cereus ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Moderate Temperature ◽  
Quality Analysis ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Enterotoxin B ◽  
Culture Supernatants

Raw and pasteurized milk samples submitted for routine quality analysis were screened for the presence of Bacillus cereus diarrheal enterotoxin (BDE) using the TECRA BDE Visual Immunoassay (VIA) kit. BDE was not detected in 298 raw milk samples tested by the TECRA VIA. B. cereus was isolated from 2 of 298 (0.7%) raw milk samples cultured. Culture supernatants from these isolates were positive for BDE in the TECRA VIA but negative in the Reverse Passive Latex Agglutination (RPLA) test for BDE. Forty-three of 112 (38.4%) pasteurized milk samples incubated at 10°C until their expiry dates were positive for BDE by the TECRA VIA. The same number of samples incubated at 4°C had no detectable levels of enterotoxin. B. cereus in the range of 103 to 106 CFU/ml was isolated from all BDE-positive pasteurized milk samples. BDE was detected in the culture supernatants of all the 43 isolates by TECRA VIA and in 30 of these isolates by RPLA. These results demonstrate that moderate temperature abuse of pasteurized milk may allow the growth of B. cereus and BDE production.

scholarly journals Microbiological quality analysis of raw, pasteurized, UHT milk samples collected from different locations in Bangladesh

2015 ◽  
Vol 4 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Sourav Kumar Banik ◽  
Kamal Kanta Das ◽  
Md Aftab Uddin
Keyword(s):  
Microbiological Quality ◽  
Bacterial Count ◽  
Raw Milk ◽  
Total Coliform ◽  
Point Of View ◽  
Quality Analysis ◽  
Expiry Date ◽  
Pasteurized Milk ◽  
Milk Samples

Present study attempted to determine the microbiological quality of raw, pasteurized and UHT (Ultra High Temperature-processed) milk samples collected from different locations in Bangladesh. A total of 46 samples were studied including 22 raw milk samples from the local dairy markets and 24 different brands of pasteurized and ultrahigh temperature (UHT) treated milk manufactured in different beverage industries. The samples were examined for determining the total viable bacterial count (TVBC) and total coliform count (TCC). Results revealed that the raw milk samples were substandard in terms of TVBC and TCC. The range of TVBC and TCC in raw milk samples was 5.2×108 to 1.3×107 cfu/ml and 4.2×104 to 1.0×104 cfu/ml, respectively. On the contrary, the quality of pasteurized and UHT-treated milks was excellent. The TVBC range in pasteurized milk samples was from 1.8×103 to 1.1×102 cfu/ml, slightly lower than that recommended by the Bangladesh Standards and Testing Institution (BSTI). Interestingly sample numbers P-6, P-10 and P-12 of pasteurized milk samples had no growth at all both in terms of TVBC and TCC and none of the UHT processed milk contained any bacteria. So from the consumer point of view, both types of processed milk can be considered safe for consumption within the mentioned expiry date. DOI: http://dx.doi.org/10.3329/sjm.v4i1.22753 Stamford Journal of Microbiology, Vol.4(1) 2014: 5-8

scholarly journals The synergistic effects of Lactobacillus acidophillus ROO52 and Lactobacillus bulgaricus LB-12 bacteriocins against E.coli O157 :H7 in milk

2014 ◽  
Vol 38 (2) ◽  
pp. 35-40
Author(s):  
Zina Saab Khudhir
Keyword(s):  
Lactobacillus Acidophilus ◽  
Synergistic Effects ◽  
Antimicrobial Effect ◽  
Average Diameter ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Lactobacillus Bulgaricus ◽  
Milk Samples ◽  
Test Kit

        The aims of this study to evaluate the antibacterial potential of standard strains (Lactobacillus acidophilus ROO52 and Lactobacillus bulgaricus LB-12) that produce bacteriocins against E.coli O157:H7 in raw milk.  Thirty raw milk samples randomly were collected weekly different markets of Baghdad city in order to investigate the prevalence of E.coli O157:H7 in milk. The prevalence of  E.coli O157:H7 in raw milk samples was  6 out 30 (20%) by using the modern chromogenic media with serological latex agglutination test kit. The average diameter of the inhibition zone of crude bacteriocin against  E .coli O157:H7 by using combination of 1:1 (v/v) of the Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12was (14mm) ,while that produced by bacteriocins of Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12  independently were 16 and 12mm respectively .L. delbrucekii ssp bulgaricus showed significantly (P<0.05) low antimicrobial effect against E.coli O157 :H7 .While the strongest antimicrobial effect was shown by Lactobacillus acidophilus ROO52. The bacteriocins of the reference strains used in this study did not result in an increase in inhibition when used in combination of 1:1 (v/v).

Low Incidence of Foodborne Pathogens of Concern in Raw Milk Utilized for Farmstead Cheese Production

2008 ◽  
Vol 71 (8) ◽  
pp. 1580-1589 ◽  
Author(s):  
DENNIS J. D'AMICO ◽  
ERROL GROVES ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Foodborne Pathogens ◽  
Microbiological Quality ◽  
Goat Milk ◽  
Raw Milk ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Cell Counts ◽  
Standard Plate ◽  
Low Incidence ◽  
Raw Milk Cheese

Overall milk quality and prevalence of four target pathogens in raw milk destined for farmstead cheesemaking was examined. Raw milk samples were collected weekly from June to September 2006 from 11 farmstead cheese operations manufacturing raw milk cheese from cow's, goat's, and sheep's milk. Samples were screened for Listeria monocytogenes, Staphylococcus aureus, Salmonella, and Escherichia coli O157:H7 both quantitatively (direct plating) and qualitatively (PCR). Overall, 96.8% of samples had standard plate counts of &lt;100,000 CFU/ml, 42.7% of which were &lt;1,000 CFU/ml. Although no federal standards exist for coliforms in raw milk, 61% of samples tested conformed to pasteurized milk standards under the U.S. Pasteurized Milk Ordinance (PMO) at &lt;10 CFU/ml. All cow and sheep milk samples and 93.8% of goat milk samples were within the limits dictated by the PMO for somatic cell counts. Of the 11 farms, 8 (73%) produced samples that were positive for S. aureus, which was detected in 34.6% (46 of 133) of milk samples. L. monocytogenes was isolated from three milk samples (2.3%), two of which were from the same farm. E. coli O157:H7 was recovered from one sample of goat's milk for an overall incidence of 0.75%. Salmonella was not recovered from any of the 133 samples. The findings of this study suggest that most raw milk intended for farmstead cheesemaking is of high microbiological quality with a low incidence of pathogens. These data will help inform risk assessments associated with the microbiological safety of farmstead cheeses, particularly those manufactured from raw milk.

scholarly journals Influence of the microbiological quality of raw milk on the shelf life of pasteurized milk

2019 ◽  
Vol 40 (4) ◽  
pp. 1469
Author(s):  
José Carlos Ribeiro Júnior ◽  
Aline Marangon de Oliveira ◽  
Fernando Godoi Silva ◽  
Lorena Natalino Haber Garcia ◽  
Cátia Maria de Oliveira Lobo ◽  
...  
Keyword(s):  
Shelf Life ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Poor Quality ◽  
Pasteurized Milk ◽  
Microbial Counts ◽  
Legal Standards ◽  
Milk Samples ◽  
Brazilian Standard

The dairy industry strives to produce high quality products with high nutritional value as well as to meet the legal standards for longer shelf life. However, these goals are made unfeasible by the poor quality of raw milk produced in some regions of Brazil. Others Brazilian dairy regions, however, already succeed in producing milk with low microbial counts, such as the municipality of Castro, Paraná state, designated as the ‘Brazilian dairy capital’. In order to evaluate the effect of raw milk quality on microbial counts during the shelf life of pasteurized milk, samples were collected from two dairy regions of Paraná: the northern and Castro region, characterized by milk production with high and low microbiological counts, respectively. Samples were experimentally pasteurized and the total microorganism counts were analyzed for 18 days at 7°C, using the Brazilian standard microbiological count limit for pasteurized milk (8 x 104 CFU/mL) as the end of the shelf life. Low microbiological counts in raw milk (Castro) resulted in significantly lower counts shortly after pasteurization and over the entire shelf life, meeting the pasteurized milk standard for 18 days. The temporal evolution in the counts over 18 days for the milks of high and low microbiological count was similar; however, the disparity between the absolute counts between the regions was significant (p < 0.05). Of the milk samples from northern Paraná, four (44.4%) already had counts higher than that of the legislative limit for pasteurized milk immediately after pasteurization. The others (five) reached the maximum microbiological count limit for pasteurized milk on the 6th day after pasteurization. In contrast, the milk from the Castro region remained below the limit throughout the analysis period. Thus, it can be stated that the microbiological quality of raw milk is directly related to the initial count of microorganisms after pasteurization, and that pasteurized milk produced from raw milk with low microbiological counts complies with the Brazilian legislation for 18 days following thermal processing.

Involvement of a pasteurizer in the contamination of milk by Bacillus cereus in a commercial dairy plant

2000 ◽  
Vol 67 (3) ◽  
pp. 455-460 ◽  
Author(s):  
BIRGITTA SVENSSON ◽  
ÅSA ENEROTH ◽  
JOHANNE BRENDEHAUG ◽  
GÖRAN MOLIN ◽  
ANDERS CHRISTIANSSON
Keyword(s):  
Bacillus Cereus ◽  
Raw Milk ◽  
Pasteurized Milk ◽  
Rapd Pcr ◽  
Random Amplification ◽  
Dairy Plant ◽  
Heat Activation ◽  
Contamination Routes ◽  
Microbiological Analyses

Bacillus cereus is a common contaminant in raw milk. The spores survive pasteurization and psychrotrophic strains of B. cereus often limit the keeping quality of pasteurized milk stored at > 6 °C (Griffiths, 1992). High numbers of B. cereus in pasteurized milk are most frequent when the cows are grazing (Slaghuis et al. 1997), mainly owing to increased levels of spores in raw milk resulting from teat contamination by soil (Christiansson et al. 1999). However, high numbers can also be found in pasteurized milk while the cows are housed indoors, and this is probably caused by additional contamination at the dairy plant (te Giffel et al. 1996; Larsen & Jørgensen, 1997; Lin et al. 1998). There is little information available about the sites of recontamination in the dairy. The use of typing techniques capable of discrimination below the species level, such as fatty acid profiles and random amplification of polymorphic DNA–polymerase chain reaction (RAPD–PCR), could be helpful in demonstrating contamination routes (Lin et al. 1998; Nilsson et al. 1998).Spores of B. cereus are very hydrophobic and readily adhere to surfaces of steel, glass and rubber (Rönner et al. 1990), and short cleaning-in-place programmes do not always eliminate all the spores (Rönner & Husmark, 1992). Spores adhering to surfaces are more difficult to eliminate by disinfectants than spores in solution (te Giffel et al. 1995). Many B. cereus spores germinate rapidly in milk upon heat activation and, if allowed to propagate undisturbed on surfaces, may form biofilms that are extremely difficult to eliminate (Mosteller & Bishop, 1993; Wirtanen et al. 1996; Kumar & Anand, 1998).This paper describes how we demonstrated the involvement of a pasteurizer in the contamination of pasteurized milk by B. cereus in a commercial dairy plant using a combination of classic microbiological analyses and typing of strains by RAPD–PCR.

scholarly journals Effect of Commercial-Scale High-Temperature, Short-Time Pasteurization on the Viability of Mycobacterium paratuberculosis in Naturally Infected Cows' Milk

2002 ◽  
Vol 68 (2) ◽  
pp. 602-607 ◽  
Author(s):  
Irene R. Grant ◽  
Edward I. Hitchings ◽  
Alan McCartney ◽  
Fiona Ferguson ◽  
Michael T. Rowe
Keyword(s):  
High Temperature ◽  
Cetylpyridinium Chloride ◽  
Raw Milk ◽  
Holding Time ◽  
Mycobacterium Paratuberculosis ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Commercial Scale ◽  
High Temperature Short Time ◽  
Short Time

ABSTRACT Raw cows' milk naturally infected with Mycobacterium paratuberculosis was pasteurized with an APV HXP commercial-scale pasteurizer (capacity 2,000 liters/h) on 12 separate occasions. On each processing occasion, milk was subjected to four different pasteurization treatments, viz., 73�C for 15 s or 25 s with and without prior homogenization (2,500 lb/in2 in two stages), in an APV Manton Gaulin KF6 homogenizer. Raw and pasteurized milk samples were tested for M. paratuberculosis by immunomagnetic separation (IMS)-PCR (to detect the presence of bacteria) and culture after decontamination with 0.75% (wt/vol) cetylpyridinium chloride for 5 h (to confirm bacterial viability). On 10 of the 12 processing occasions, M. paratuberculosis was detectable by IMS-PCR, culture, or both in either raw or pasteurized milk. Overall, viable M. paratuberculosis was cultured from 4 (6.7%) of 60 raw and 10 (6.9%) of 144 pasteurized milk samples. On one processing day, in particular, M. paratuberculosis appeared to have been present in greater abundance in the source raw milk (evidenced by more culture positives and stronger PCR signals), and on this occasion, surviving M. paratuberculosis bacteria were isolated from milk processed by all four heat treatments, i.e., 73�C for 15 and 25 s with and without prior homogenization. On one other occasion, surviving M. paratuberculosis bacteria were isolated from an unhomogenized milk sample that had been heat treated at 73�C for 25 s. Results suggested that homogenization increases the lethality of subsequent heat treatment to some extent with respect to M. paratuberculosis, but the extended 25-s holding time at 73�C was found to be no more effective at killing M. paratuberculosis than the standard 15-s holding time. This study provides clear evidence that M. paratuberculosis bacteria in naturally infected milk are capable of surviving commercial high-temperature, short-time pasteurization if they are present in raw milk in sufficient numbers.

scholarly journals βeta-lactam and Tetracycline Antibiotic Residues in Cow Milk in the Constantine region, Algeria

2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Noureddine Zeghilet ◽  
Brahim Bouchoucha ◽  
Omar Bouaziz
Keyword(s):  
Milk Sample ◽  
Dairy Industry ◽  
Raw Milk ◽  
Control Programme ◽  
Cow Milk ◽  
Antibiotic Residues ◽  
Pasteurized Milk ◽  
Tetracycline Antibiotic ◽  
Milk Samples ◽  
Antibiotics Residues

The aim of the present study was to investigate the βeta-lactam and tetracycline antibiotic residues in cow milk samples. A total of 122 samples of cow milk were collected from raw milk collectors (109 samples) and from a reconstituted pasteurized milk sales clerk (13 samples) in the Constantine region, Algeria and examined using the ΒetaStar Combo screening kit (Neogen, USA). Results indicates that 13 samples (10.66%) were positive for antibiotics residues: 12 (9.84%) for βeta-lactams (ten (8.20%) raw and two (1.64%) pasteurized milk samples) and only one (0.82%) for tetracyclines in a raw milk sample. It is evident that the Algerian consumer is not sheltered from the danger of antibiotic residues in milk and these inhibitor residues should constitute a constant concern for the dairy industry in Algeria. A control programme should be established.

scholarly journals Quality Analysis of Milk in Kathmandu Valley

2018 ◽  
Vol 5 ◽  
pp. 7-10
Author(s):  
Astha Parajuli ◽  
Prasiddhi Rimal ◽  
Rujisha Maharjan ◽  
Richa Chaudhary ◽  
Shashi Bhusan Chaturwedi
Keyword(s):  
Milk Sample ◽  
Milk Fat ◽  
Raw Milk ◽  
Fat Content ◽  
Quality Analysis ◽  
Kathmandu Valley ◽  
Microbiological Analysis ◽  
Milk Samples ◽  
Quality Of Milk

Objectives: This study was carried out to evaluate physiochemical, adulteration and microbial quality of milk sold in Kathmandu Valley. Methods: The study was carried out in Microbiology Laboratory of DAV College. The total of 20 milk samples randomly collected from different places of the valley including 10 pasteurized milk sample and 10 were raw milk sample, were processed for Physiochemical and Microbiological analysis. Result: The laboratory analysis revealed that the pasteurized samples has less mesophilic count as well as coliform count than raw milk samples. About 55% milk samples showed neutralizer test positive and 10% of milk samples were found to be positive for sugar test. However, none of the samples were found to contain starch as an adulterant. The average fat content of milk samples of Kathmandu Valley was 3%. Fat percent was significantly different among different sources of sampling points. The highest milk fat content value was recorded at Pulchowk (3.7%). The average SNF of Kathmandu Valley was 7% in which the pasteurized sample had the highest average SNF (7.3%) and the raw milk had lowest average SNF (6.8%). Conclusion: The significant variation in the physiochemical properties and microbial properties of the milk samples showed that people should be conscious about the consumption of market milk.  

Characterization of protein-lipid interaction and redistribution of minerals in infant formula by CTEM and EDS

1994 ◽  
Vol 52 ◽  
pp. 188-189
Author(s):  
G. M. Hendricks ◽  
M. R. Guo ◽  
P. S. Kindstedt
Keyword(s):  
Infant Formula ◽  
Raw Milk ◽  
Mineral Distribution ◽  
Pasteurized Milk ◽  
Lipid Interactions ◽  
Milk Samples ◽  
Infant Formulae ◽  
Fat Fraction ◽  
Lipid Interaction

The protein-protein and protein-lipid interactions in 3 commercial powdered infant formulae were compared to raw and pasteurized milk samples. Centrifugation of the infant formulae and milk samples for 2 hr at 4°C gave 3 distinct fractions: fat, serum, and pellet. The objective of this study was to determine the mineral distribution (i.e., Ca, P, Mg, K, Na, Zn, and Fe) among the fat, serum and pellet fractions obtained by centrifugation. Recoveries of individual minerals from the 3 fractions exceeded 90% in all cases. Ca in the fat fraction of infant formulae ranged from 17.5% to 32%, where as only 1.4% and 1.7% of the total Ca was recovered in the fat fraction of the raw milk and the pasteurized milk samples. P, Zn, Mg, and Fe followed similar patterns with respect to the fat fraction. In contrast, 80 to 90% of the K and Na were found in the serum fraction of the infant formulae and milk samples.

THE ROLE OF BACILLUS CEREUS IN SWEET CURDLING OF FLUID MILK

1974 ◽  
Vol 37 (5) ◽  
pp. 233-236 ◽  
Author(s):  
W. W. Overcast ◽  
Krishnaswamy Atmaram
Keyword(s):  
Bacillus Cereus ◽  
Pseudomonas Fluorescens ◽  
Raw Milk ◽  
Causative Organism ◽  
Refrigerated Storage ◽  
Pseudomonas Fragi ◽  
Milk Samples ◽  
Pseudomonas Species ◽  
Heat Activation

Twenty-eight percent of commercially pasteurized milk samples procured from various plants throughout Tennessee exhibited sweet-curdling within 10 days on refrigerated storage. Psychrotrophic Bacillus cereus was isolated as a causative organism from these milk samples. The isolates differed from the type culture organism only in their ability to grow and bring about sweet curd formation in skimmilk at refrigeration temperature. These isolates exhibited marked differences in their response to heat activation temperatures as well as to the initial excessive growth of Pseudomonas species in raw milk. Spores of three isolates exhibited greater activity after activation at 80 C for 15 sec than at the standard pasteurization temperature of 71.5 C for 15 sec. Excessive growth of Pseudomonas fragi or Pseudomonas fluorescens in raw skimmilk before processing had a stimulatory effect on two of three psychrotrophic Bacillus cereus isolates in combination with heat-activation especially with activation at 80 C for 15 sec.

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