A Study on the Prevalence of Gram-Negative Bacteria in Bulk Tank Milk

Jayarao, B.M.; Wang, L.

doi:10.3168/jds.s0022-0302(99)75518-9

Cited by 95 publications

(68 citation statements)

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“…In contrast, no standard is available for BTMS culturing for the detection of mastitis pathogen contamination. Various authors were used different media for this purpose (Fenlon et al, 1995;Benda and Vyletelova, 1997a,b;Jayarao and Wang, 1999;Hayes et al, 2001;Sawant et al, 2002;Jayarao et al, 2004;Zadoks et al, 2004;Olde Riekerink et al, 2006). We have used culture media similar to the recommendation of the National Mastitis Council (2005) for the purpose of this study.…”

Section: Discussionmentioning

confidence: 99%

Bulk tank milk somatic cell count and sources of raw milk contamination with mastitis pathogens

Rysanek¹,

Babák²,

Zouharová³

2007

Vet. Med. - Czech

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The objective of this study was to probe the relationship between prevalence of selected principal mastitis pathogens and somatic cell counts in bulk tank milk samples. The sources of milk contamination were evaluated. The samples were collected from 298 dairy herds (with approximately 32 000 dairy cows). Only 48.3% of the bulk tank milk samples were free of contamination of pathogens of interest. Approximately 38.9% of the milk samples were contaminated with only one, 12.4% with two and 0.3% with three pathogens. The arithmetic mean of logarithmically transformed data of bulk tank milk somatic cell count rise in order: pathogen free, Pseudomonas aeruginosa, Streptococcus uberis, Escherichia coli and Staphylococcus aureus (5.381; 5.413; 5.495; 5.518; 5.563, respectively). The arithmetic mean differences between bulk tank milk somatic cell counts in pathogen-free and single-pathogen contaminated samples have revealed a significance for the Escherichia coli and Staphylococcus aureus groups (P < 0.01). Using binary logistic regression, a statistically highly significant relationship (P < 0.001) has been found between the number of contaminations of bulk tank milk samples with mastitis pathogens and bulk tank milk somatic cell counts. The relationship allows the determination of the probability of finding relevant mastitis pathogens in bulk tank milk samples with different levels of bulk tank milk SCC. A 63% probability can be defined at a cell count level of 400 000/ml and 20% at a cell count level of 100 000/ml. Analysis may reveal the potential sources of the bulk tank milk sample contamination, i.e. infected mammary glands or the environment. The presence of high levels of contamination along with a low bulk tank SCC may suggest an environmental source of contamination. The study clarified that a potential source of bulk tank milk contamination by relevant pathogens (the environment or the mammary gland) may be elucidated and the probability of the contamination of bulk tank milk samples with mastitis pathogens predicted by the analysis of relationship between the bulk tank milk somatic cell counts and the number of mastitis pathogen contaminations.

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Section: Discussionmentioning

confidence: 99%

Bulk tank milk somatic cell count and sources of raw milk contamination with mastitis pathogens

Rysanek¹,

Babák²,

Zouharová³

2007

Vet. Med. - Czech

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“…count was 43% of the total psychrotrophic Gram negative strains, and P. fluorescens was the most common specie (37.6%), which was followed by P. putida. Conversely, P. fluorescens was the predominant species (29.9%) in cooled raw milk in the USa (JaYaRaO & WaNG, 1999). The time elapsed between sampling of cooled raw milk at the farms and its arrival to the dairy plant was 6 h. However, the authors observed that milk remained in the bulk tank for up to 10h, was stored in the cooling tanks for more than 48h on many occasions.…”

Section: Characteristics --------------------------------------------mentioning

confidence: 99%

“…represents the most frequent deteriorating psychrotrophic microflora in refrigerated raw milk, and Pseudomonas fluorescens is the most frequently reported species (JaYaRaO & WaNG, 1999;FaGUNDES et al, 2006;aRCURI et al, 2008;SaNTOS et al, 2009). Due to the changes in the entire milk production in Brazil, verifying the impact of raw milk cooling at dairy farms on Pseudomonas spp.…”

Section: Resumo: Amostras De Leite Foram Coletadas De Tanques De Refrmentioning

confidence: 99%

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Pseudomonas spp. and P. fluorescens: population in refrigerated raw milk

et al. 2017

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Pseudomonas spp. and P. fluorescens: population in refrigerated raw milk.Ciência Rural, v.47, n.1, 2017. IntRoDuCtIonGuidelines for cooling milk in dairy farms and its transportation were established in Brazil in 2002 (BRaSIl, 2002 as a response to international regulations and market demands. Since then, changes in milk chain production profile and qualitative advances in the regulation of total bacterial (TBC) and somatic cell (SCC) counts in raw milk have occurred (BRaSIl, 2002), and the guidelines were updated in 2011 (BRaSIl, 2011

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“…In 2009, the same bacteria were detected at 2.6, 14.6, 10.6, 5.3, 13.3, 16, 24, 9.3 and 4% of 75 isolates, respectively. Previous studies that identified Gram-negative bacteria isolated from bulk tank milk of healthy animals attributed the source of contamination by these bacteria to be inefficient cleaning of the udder before milking or contamination from utensils and milking machines [9]. In our study, to exclude contamination from such sources and to give new insights regarding the bacterial community in healthy udders, we obtained milk samples manually after sterilization of the udders and surrounding tissue.…”

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confidence: 99%

Asymptomatic Intramammary Infection with Multidrug-Resistant Gram-Negative Bacteria in a Research Dairy Farm: Incidence and Genetic Basis of Resistance

Hammad

Shimamoto

2011

The Journal of Veterinary Medical Science

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ABSTRACT. Nonpathogenic and opportunistic bacteria are increasingly recognized as reservoirs of antibiotic resistance genes. However, nothing is known about the mechanisms of antibiotic resistance in such bacteria isolated from the udders of healthy animals. In this study, 150 Gram-negative strains isolated from milk samples of healthy dairy cows were screened for the presence of a large pool of antibiotic resistance markers. Strains carrying -lactamase-resistance genes, including SHV-1, SHV-11, SHV-27, TEM-1, OXY-1, CTX-M-2 and class 1 integrons, were detected. Our findings give the first evidence that nonpathogenic and opportunistic bacteria carrying antibiotic resistance genes can asymptomatically invade healthy udders and suggest that they may play a role in the dissemination of antibiotic resistance genes to the other udder pathogens.KEY WORDS: antibiotic resistance, Gram-negative bacteria, udder.J. Vet. Med. Sci. 73(8): 1089-1092, 2011 The call for more successful udder health control programs is becoming more important in the context of animal health and public health. Even though it has been shown how well the Hazard Analysis and Critical Control Points (HACCP) approach [13] fits well in the udder health control concept, mastitis is still a major problem in dairy herds. Unfortunately, testing plans for monitoring multidrug-resistant opportunistic pathogens in samples from bulk tank milk, individual cows, and the dairy environment are still undefined in any HACCP program for the control of mastitis. Monitoring dairy farms for the presence of multidrugresistant bacteria would assist in the development of appropriate strategies for the prevention and control of udder infections. The recent development of tools that allow the molecular epidemiological survey of antibiotic resistance mechanisms is likely to be important for directing treatments and to have worldwide economic implications.Currently, the treatment choices for clinical mastitis can be based on the knowledge of the herd-level sensitivity patterns of the predominant bacterial strains [2]. Such herdlevel knowledge can be obtained through sensitivity testing of clinical isolates after treatment has been initiated. However, in vitro susceptibility tests have been shown to be poor predictors of treatment outcomes [1]. Such clinical outcomes are likely to be either a complication of cases of mastitis by different multidrug-resistant opportunistic pathogens previously invading the udders or the evolution of resistance mechanisms in the causative agent during therapy through mutations or lateral dissemination of antibiotic resistance determinants.Molecular epidemiological studies together with application of strict hygienic measures are only now being implemented in dairy farms all over the world as a result of mastitis outbreaks [12]. Given that the penetration of coliforms into the bovine teat duct during intermilking periods has been well documented [4,20], a better understanding of the antibiotic resistance mechanisms in the bacteria responsible for...

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A Study on the Prevalence of Gram-Negative Bacteria in Bulk Tank Milk

Cited by 95 publications

References 9 publications

Bulk tank milk somatic cell count and sources of raw milk contamination with mastitis pathogens

Bulk tank milk somatic cell count and sources of raw milk contamination with mastitis pathogens

Pseudomonas spp. and P. fluorescens: population in refrigerated raw milk

Asymptomatic Intramammary Infection with Multidrug-Resistant Gram-Negative Bacteria in a Research Dairy Farm: Incidence and Genetic Basis of Resistance

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