scholarly journals The occurrence of Campylobacter spp., Listeria monocytogenes and Shiga toxin-producing Escherichia coli in Norwegian dairy cattle farms; a comparison between free stall and tie stall housing systems.

2021 ◽  
Author(s):  
Lene Idland ◽  
Erik G. Granquist ◽  
Marina Aspholm ◽  
Toril Lindbäck
Keyword(s):  
Dairy Farm ◽  
Raw Milk ◽  
Bulk Tank Milk ◽  
Housing Systems ◽  
Unpasteurized Milk ◽  
Bulk Tank ◽  
Zoonotic Bacteria ◽  
Cattle Farms ◽  
Norwegian Dairy ◽  
Campylobacter Spp

Abstract Aims: This study explores how different dairy farm operating systems influence the occurrence of zoonotic bacteria in raw milk. Methods and Results: Samples from bulk tank milk, milk filters, feces, feed, teats and teat milk were collected from eleven farms with loose housing and seven with tie-stall housing every second month over a period of 11 months and analyzed for the presence of Campylobacter spp., L. monocytogenes and STEC. Campylobacter spp., L. monocytogenes and STEC were abundant in samples from the farm environment and were also detected in 4%, 13% and 7% of the milk filters, respectively, and in 3%, 0% and 1% of bulk tank milk samples. Four STEC isolates carried the eae gene, which is linked to the capacity to cause more severe human disease. Conclusion: The results indicate a higher prevalence of L. monocytogenes and Campylobacter spp. in samples collected from loose housed herds compared to tie-stalled herds suggesting that the operating system can influence the food safety of raw milk. Significance and Impact of the study: This study highlights that zoonotic bacteria can be present in raw milk independent of hygienic conditions at the farm and what hosing system is used. Altogether, this study provides an important knowledge base for evaluating the risk of drinking unpasteurized milk.

Survey of Ontario Bulk Tank Raw Milk for Food-Borne Pathogens

1997 ◽  
Vol 60 (11) ◽  
pp. 1341-1346 ◽  
Author(s):  
MARINA L. STEELE ◽  
W. BRUCE McNAB ◽  
CASE POPPE ◽  
MANSEL W. GRIFFITHS ◽  
SHU CHEN ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Raw Milk ◽  
Plate Count ◽  
Salmonella Spp ◽  
Food Borne Pathogens ◽  
Unpasteurized Milk ◽  
Food Borne ◽  
The Mean ◽  
Bulk Tank ◽  
Campylobacter Spp

Raw (unpasteurized) milk can be a source of food-borne pathogens. Raw milk consumption results in sporadic disease outbreaks. Pasteurization is designed to destroy all bacterial pathogens common to raw milk, excluding spore-forming bacteria and possibly Mycobacterium paratuberculosis, but some people continue to drink raw milk, believing it to be safe. Current methods for assessing the bacteriological quality of raw milk, such as aerobic plate counts, are not usually designed to detect specific pathogens. The objective of this study was to estimate the proportion of pick-ups (loads of raw milk from a single farm bulk tank) from Ontario farm bulk tanks that contained Listeria monocytogenes. Salmonella spp., Campylobacter spp., and/or verotoxigenic Escherichia coli (VTEC). Samples from 1,720 pick-ups of raw milk were tested for the presence of these pathogens, and 47 L. monocytogenes, three Salmonella spp., eight Campylobacter spp., and 15 VTEC isolates were detected, representing 2.73, 0.17, 0.47, and 0.87% of milk samples, respectively. Estimates of the proportion of theoretical tanker truck loads of pooled raw milk contaminated with pathogens ranged from a low of 0.51 % of tankers containing raw milk from 3 bulk tanks being contaminated with Salmonella spp. to a high of 34.41 % of tankers containing raw milk from 10 bulk tanks being contaminated with at least one of the pathogens. Associations between the presence of pathogens and raw milk sample characteristics were investigated. The mean somatic cell count was higher among VTEC- or L. monocytogenes-positive samples, and the mean aerobic plate count was found to be higher among L. monocytogenes-positive samples. These results confirm the presence of bacterial food pathogens in raw milk and emphasize the importance of continued diligence in the application of hygiene programs within dairies and the separation of raw milk from pasteurized milk and milk products.

Evaluation of virulence factors profiles and antimicrobials resistance of Escherichia coli isolated from bulk tank milk and raw milk filters

2019 ◽  
Vol 123 ◽  
pp. 77-83 ◽  
Author(s):  
Francesca Dell'Orco ◽  
Claudia Gusmara ◽  
Monica Loiacono ◽  
Theo Gugliotta ◽  
Francesca Albonico ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Raw Milk ◽  
Bulk Tank Milk ◽  
Bulk Tank

Detection and Fate of Bacillus anthracis (Sterne) Vegetative Cells and Spores Added to Bulk Tank Milk†

2003 ◽  
Vol 66 (12) ◽  
pp. 2349-2354 ◽  
Author(s):  
MICHAEL L. PERDUE ◽  
JEFF KARNS ◽  
JIM HIGGINS ◽  
JO ANN VAN KESSEL
Keyword(s):  
Bacillus Anthracis ◽  
Protective Antigen ◽  
Lethal Factor ◽  
Raw Milk ◽  
Molecular Data ◽  
Molecular Techniques ◽  
Nucleotide Sequence Analysis ◽  
Vegetative Cells ◽  
Bulk Tank Milk ◽  
Bulk Tank

A preparation of Bacillus anthracis (Sterne strain) spores was used to evaluate commercially available reagents and portable equipment for detecting anthrax contamination by using real-time PCR and was used to assess the fate of spores added directly to bulk tank milk. The Ruggedized Advanced Pathogen Identification Device (RAPID) was employed to detect spores in raw milk down to a concentration of 2,500 spores per ml. Commercially available primers and probes developed to detect either the protective antigen gene or the lethal factor gene both provided easily read positive signals with the RAPID following extraction from milk with a commercially available DNA extraction kit. Nucleotide sequence analysis of the vrrA gene with the use of DNA extracted from spiked milk provided molecular data that readily identified the spores as B. anthracis with a 100% BLAST match to the Sterne and Ames strains and easily distinguished them from B. cereus. Physical-fate and thermal-stability studies demonstrated that spores and vegetative cells have a strong affinity for the cream fraction of whole milk. A single treatment at standard pasteurization temperatures, while 100% lethal to vegetative cells, had no effect on spore viability even 14 days after the treatment. Twenty-four hours after the first treatment, a second treatment at 72°C for 15 s reduced the viability of the population by ca. 99% but still did not kill all of the spores. From these studies, we conclude that standard pasteurization techniques for milk would have little effect on the viability of B. anthracis spores and that raw or pasteurized milk poses no obstacles to the rapid detection of the spores by molecular techniques.

Herd factors influencing free fatty acid concentrations in bulk tank milk

2019 ◽  
Vol 86 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Lars Wiking ◽  
Martin Bjerring ◽  
Mette Marie Løkke ◽  
P. Løvendahl ◽  
T. Kristensen
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Production System ◽  
Onset Time ◽  
Raw Milk ◽  
Bulk Tank Milk ◽  
Bulk Milk ◽  
Milking Frequency ◽  
Technical Factors ◽  
Bulk Tank

AbstractFree fatty acid (FFA) concentrations can be elevated in raw milk due to improper handling and management at the dairy farm, and high concentrations of FFA can lead to off flavors in milk. This study aimed to describe how the herd production system, milking system, feeding and technological factors impact on FFA concentrations in bulk tank milk. FFA concentrations in bulk milk samples from 259 organic and 3326 conventional herds were analyzed by FT-IR during one year. The FFA content was significantly lower in bulk milk from organic than conventional herds. This was most evident during the summer half-year when the organic cows graze pasture. Bulk milk from automatic milking systems (AMS) and tie-stalls contained greater concentrations of FFA than any other milking parlor systems. In AMS, high milking frequency was found to be the most significant contributor to elevated FFA content in milk. Moreover, a strong interaction was found between milking interval and production system (organic vs. conventional). The technical factors, pre-cooling, onset time for cooling after milk inlet, contact between milk and agitation also impacted on the FFA concentration, whereas other technical factors including centrifugal pump type, length and height of pumping line and type of AMS manufacturer were found to be without significant effect on FFA. Feeding variables, based on feeding plans and evaluation, only explained a small part of the variation in bulk milk FFA. Overall, this study demonstrated that AMS compared to other milking system contributes significantly to increased FFA concentration in bulk tank milk, and within AMS high milking frequency contributes to increased FFA concentration.

scholarly journals Prevalence, Virulence, and Antimicrobial Resistance of Campylobacter spp. in Raw Milk, Beef, and Pork Meat in Northern Poland

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 420 ◽  
Author(s):  
Małgorzata Andrzejewska ◽  
Bernadeta Szczepańska ◽  
Dorota Śpica ◽  
Jacek J. Klawe
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Food Samples ◽  
Diffusion Method ◽  
Marker Genes ◽  
Vending Machines ◽  
Source Of Infection ◽  
Unpasteurized Milk ◽  
Resistance Rates ◽  
Campylobacter Spp

The purpose of this study was to determine whether raw milk, unpasteurized dairy products, pork, and beef available for sale in the Kujawsko-Pomorskie and Wielkopolska regions in Poland are contaminated with Campylobacter spp. bacteria and may be a potential source of infection. For isolated strains, antibiotic susceptibility and the presence of genes responsible for virulence were examined. Material for research included 1058 food samples collected between 2014 and 2018 with 454 samples of raw milk and unpasteurized dairy products (milk from vending machines, milk from owners of dairy cows, cheese, milk cream) and 604 samples of raw meat (pork, beef). The results indicated that 9.3% of the samples were positive for Campylobacter spp., and Campylobacter jejuni was predominant in this study. Campylobacter bacteria was not found in milk collected from vending machines, as well as cheese and milk cream samples. Campylobacter was noted in 12.7% of beef samples, 11.8% of raw milk purchased from individual suppliers, and 10.9% of pork samples. Resistance to erythromycin (2.0%), azithromycin (3.1%), gentamicin (4.1%), tetracycline (65.3%), and ciprofloxacin (71.4%) was determined using the disc diffusion method. Furthermore, the prevalence of racR, sodB, csrA, virB11, cdtB, iam, and wlaN genes were examined using the PCR method. The sodB, csrA, and cdtB genes exhibited the highest detection rate, but none of the genes were identified in 100% of the isolates. Statistically significant differences between the presence of virulence marker genes, including for iam, racR, and csrA markers, were noted among different sources of the isolates. Differences in the distribution of iam, wlaN, and virB11 were also shown between C. jejuni and C. coli strains. As a result of the analysis, it has been concluded that unpasteurized milk, beef, and pork could be a sources of Campylobacter pathogens. Moreover, this study revealed virulent properties of Campylobacter isolated from such food products and high resistance rates to fluoroquinolones, which may represent difficulties in campylobacteriosis treatment.

Listeria monocytogenes in the Irish Dairy Farm Environment

2009 ◽  
Vol 72 (7) ◽  
pp. 1450-1456 ◽  
Author(s):  
EDWARD FOX ◽  
TOM O'MAHONY ◽  
MARIE CLANCY ◽  
RITA DEMPSEY ◽  
MARTINA O'BRIEN ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Chain ◽  
Foodborne Pathogen ◽  
Dairy Farm ◽  
Raw Milk ◽  
Hygiene Practices ◽  
Unpasteurized Milk ◽  
Cheese Industry ◽  
Chromogenic Agar ◽  
Pcr Targeting

Listeria monocytogenes is a potentially lethal foodborne pathogen commonly found in the environment. European Union hygiene legislation places responsibility for safety on primary production facilities, including farms, as part of a policy to introduce traceability throughout the food chain. This study aimed to determine the occurrence of L. monocytogenes in the Irish dairy farm environment and in particular the milking facility. Two hundred ninety-eight environmental samples were collected from 16 farms in the southern region of Ireland. A number of farms within the group supply raw milk to the unpasteurized milk cheese industry. The samples taken included cow feces, milk, silage, soil, water, etc. Samples were enriched in Listeria enrichment broth and incubated for 48 h, followed by plating on chromogenic agar Listeria Ottavani & Agosti and further incubation of the plates for 24 to 48 h. Presumptive L. monocytogenes isolates were purified and confirmed by PCR targeting the hly gene. Overall, 19% of the samples (57 of 298) were positive for L. monocytogenes. These were serotyped using conventional and PCR methods; serotypes 1/2a, 1/2b, and 4b made up 78% of the typeable isolates. A correlation was found between the level of hygiene standards on the farm and the occurrence of L. monocytogenes. There was little difference in the occurrence of L. monocytogenes between farms supplying milk to the unpasteurized milk cheese industry and those supplying milk for processing. This study demonstrates the prevalence of L. monocytogenes in the dairy farm environment and the need for good hygiene practices to prevent its entry into the food chain.

Estimating Bacterial Pathogen Levels in New Zealand Bulk Tank Milk

2016 ◽  
Vol 79 (5) ◽  
pp. 771-780 ◽  
Author(s):  
J. C. MARSHALL ◽  
T. K. SOBOLEVA ◽  
P. JAMIESON ◽  
N. P. FRENCH
Keyword(s):  
New Zealand ◽  
Predictive Model ◽  
Pathogenic Bacteria ◽  
Fecal Contamination ◽  
Raw Milk ◽  
Quality Data ◽  
Bulk Tank Milk ◽  
E Coli ◽  
Cell Counts ◽  
Bulk Tank

ABSTRACT Zoonotic bacteria such as Campylobacter, Listeria, and Shiga toxin–producing Escherichia coli have been found in bulk tank milk in many countries, and the consumption of raw milk has been implicated in outbreaks of disease in New Zealand. Fecal contamination at milking is probably the most common source of pathogenic bacteria in bulk tank milk. Raw milk was collected from 80 New Zealand dairy farms during 2011 and 2012 and tested periodically for Campylobacter, E. coli O157, Listeria monocytogenes, and Salmonella. Milk quality data such as coliform counts, total bacterial counts, and somatic cell counts also were collected. By treating the total bacterial count as a proxy for fecal contamination of milk and utilizing farm and animal level prevalence and shedding rates of each pathogen, a predictive model for the level of pathogenic bacteria in bulk tank raw milk was developed. The model utilizes a mixture distribution to combine the low level of contamination inherent in the milking process with isolated contamination events associated with significantly higher pathogen levels. By simulating the sampling and testing process, the predictive model was validated against the observed prevalence of each pathogen in the survey. The predicted prevalence was similar to the observed prevalence for E. coli O157 and Salmonella, although the predicted prevalence was higher than that observed in samples tested for Campylobacter.

scholarly journals A new integrated approach to analyze bulk tank milk and raw milk filters for the presence of the E. coli serogroups frequently associated with VTEC status

2017 ◽  
Vol 115 ◽  
pp. 401-406 ◽  
Author(s):  
Francesca Albonico ◽  
Claudia Gusmara ◽  
Theo Gugliotta ◽  
Monica Loiacono ◽  
Michele Mortarino ◽  
...  
Keyword(s):  
Raw Milk ◽  
Integrated Approach ◽  
Bulk Tank Milk ◽  
E Coli ◽  
Bulk Tank

scholarly journals Iodine content in bulk tank milk samples in relation to dairy farm size

2014 ◽  
Vol 83 (10) ◽  
pp. S9-S13 ◽  
Author(s):  
Lenka Vorlová ◽  
Lucia Hodulová ◽  
Ivana Borkovcová ◽  
Hana Přidalová ◽  
Romana Kostrhounová ◽  
...  
Keyword(s):  
Dairy Farm ◽  
Iodine Content ◽  
Dairy Farms ◽  
Raw Milk ◽  
Farm Size ◽  
Milk Samples ◽  
Significant Difference ◽  
Organic Dairy ◽  
Bulk Tank ◽  
Organic Dairy Farms

The aim of this study was to compare the iodine content in raw milk from organic and conventional dairy farms of different sizes. Milk samples were collected between 2012 and 2013, and the iodine content was determined by a Sandell-Kolthoff reaction after dry alkaline digestion of the milk samples. Comparing the iodine content in raw milk samples from small sized dairy farms (116.76 ± 46.29 μg/l) and large sized dairy farms (173.70 ± 35.42 μg/l), a significant difference in iodine content was observed (P ≤ 0.05). The lowest values were found in small and medium dairy farms, 45.30 μg/l and 40.46 μg/l, respectively. High variability (112.92 ± 94.74 μg/l) in the iodine content was detected in raw milk from medium sized dairy farms. When considering milk samples from organic dairy farms (119.29 μg /l ± 40.37) vs. conventional dairy farms (136.55 μg/l ± 42.91), no significant difference was detected. These results indicate higher iodine content in milk from large dairy farms regardless of conventional or organic farming methods.

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