Molecular characteristics of Escherichia coli from bulk tank milk in Korea

Abstract Background This study was conducted to analyze the genetic characteristics of 41 β-lactam-resistant Escherichia coli isolates, which are one of the common causes of environmental mastitis, isolated from the bulk tank milk of 290 dairy farms in five factories operated by three dairy companies in Korea. Results Analysis of the phenotypic and genotypic characteristics of β-lactam-resistant E. coli isolates revealed differences between factories even within the same company. Isolates from factory A1 and C1 showed high resistance to cephalothin (76.9 and 100%, respectively), which is a first-generation cephalosporins, whereas resistance to tetracycline was showed by only the isolates from factories B1 (60.0%), C2 (66.7%), and C3 (100%). Although all the 41 β-lactam-resistant E. coli isolates were positive for blaOXA-1, blaTEM-1 was highly prevalent in isolates from factories C2 (100%) and C3 (100%). Among 17 isolates resistant to both β-lactams and aminoglycosides, the most common multilocus sequence type was ST399 (13isolates, 76.5%). Furthermore, 2 (11.8%) and 12 (70.6%) isolates belonged to the phylogenetic groups B2 and D, respectively, which are invasive strains that cause intestinal infections, respectively. The predominant serogroup was O15 (70.6%), which is a globally distributed extraintestinal pathogen. Interestingly, one isolate from factory A1 belonged to O157 and carried six virulence genes, simultaneously. Conclusions Although E. coli isolates were isolated from bulk tank milk, and not the clinical mastitis samples, the presence of the phylogenetic groups B2 and D, and the serogroups O15 and O157, which harbor antimicrobial resistance genes and virulence factors, can pose a threat to public health.

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Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study

Journal of Dairy Science ◽

10.3168/jds.2017-13546 ◽

2018 ◽

Vol 101 (3) ◽

pp. 1943-1956 ◽

Cited By ~ 21

Author(s):

Jakeitha L. Sonnier ◽

Jeffrey S. Karns ◽

Jason E. Lombard ◽

Christine A. Kopral ◽

Bradd J. Haley ◽

...

Keyword(s):

Escherichia Coli ◽

Listeria Monocytogenes ◽

Monitoring System ◽

Health Monitoring ◽

Salmonella Enterica ◽

Animal Health ◽

Bulk Tank Milk ◽

Health Monitoring System ◽

Pathogenic Escherichia Coli ◽

Bulk Tank

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The examination of presumed Escherichia coli count of raw milk samples on several milk production farms

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/21/3170 ◽

2006 ◽

pp. 31-37

Author(s):

Ferenc Peles ◽

András Szabó ◽

Béla Béri ◽

Péter Keresztúri

Keyword(s):

Escherichia Coli ◽

Raw Milk ◽

Coliform Bacteria ◽

Farm Size ◽

Small Farms ◽

Bulk Tank Milk ◽

E Coli ◽

Significant Difference ◽

Bulk Tank ◽

Large Farms

For dairy farms, it is of great importance to insure the appropriate hygienic status of milk and to examine it regularly. Escherichia coli, belonging to the coliform bacteria type of, is a good indicator of contamination, and therefore suitable for characterising the hygienic condition of milk production.The aim of our research was to examine the connection between the Escherichi coli count in bulk tank milk and housing and milking technologies of different-sizes farms. We examined the relation using various statistical methods.Analysing the connection between the E. coli count and the farm size we found no significant difference between the farms. On the basis of the mean values of the E. coli count, we can say that the hygienic conditions are appropriate for mid-sized farms, and tolerable for large farms. We found differences in the hygienic status among the small farms. Half of the eight small farms, had no adequate hygiene. The results of the analysis of the quality categories show that the probability of inadequate quality milk was the largest on small farms (37.5%).Comparing the various housing and milking methods with each other, there were numerical differences in the E. coli count, but these differences were not significant. We got higher E. coli count values on those farms using tied stall barn and bucket milking installation. The reason for this could be that in cases of farms using bucket milking installation, it is harder to meet the requirements.After forming groups by farm size, housing and milking methods, we found that the E. coli counts are adequate on mid-size farms using various housing and milking methods; and tolerable on those large farms using loose housing stable and a milking parlour. At the same time, we found inadequate E. coli counts on the smaller farms using tied stall barns and bucket milking installation.The results show that if there is suitable attention, independent of farm size, housing and milking procedure, it is possible to produce milk with low E. coli counts, and to insure appropriate hygienic conditions.Further detailed examinations are needed to decide which factors of housing and milking technologies influence the E. coli count of bulk tank milk.

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Characteristics of Escherichia coli from bulk tank milk of dairy company

Journal of Preventive Veterinary Medicine ◽

10.13041/jpvm.2020.44.4.236 ◽

2020 ◽

Vol 44 (4) ◽

pp. 236-239

Keyword(s):

Escherichia Coli ◽

Bulk Tank Milk ◽

Bulk Tank

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Prevalence of Salmonella enterica, Listeria monocytogenes, and Escherichia coli Virulence Factors in Bulk Tank Milk and In-Line Filters from U.S. Dairies†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-423 ◽

2011 ◽

Vol 74 (5) ◽

pp. 759-768 ◽

Cited By ~ 65

Author(s):

JO ANN S. VAN KESSEL ◽

JEFFREY S. KARNS ◽

JASON E. LOMBARD ◽

CHRISTINE A. KOPRAL

Keyword(s):

Escherichia Coli ◽

Listeria Monocytogenes ◽

Real Time ◽

Real Time Pcr ◽

Salmonella Enterica ◽

Raw Milk ◽

The United States ◽

Bulk Tank Milk ◽

Milk Products ◽

Bulk Tank

The zoonotic bacteria Salmonella enterica, Listeria monocytogenes, and Escherichia coli are known to infect dairy cows while not always causing clinical signs of disease. These pathogens are sometimes found in raw milk, and human disease outbreaks due to these organisms have been associated with the consumption of raw milk or raw milk products. Bulk tank milk (BTM) samples (536) and in-line milk filters (519) collected from dairy farms across the United States during the National Animal Health Monitoring System's Dairy 2007 study were analyzed by real-time PCR for the presence of S. enterica and pathogenic forms of E. coli and by culture techniques for the presence of L. monocytogenes. S. enterica was detected in samples from 28.1% of the dairy operations, primarily in milk filters. Salmonella was isolated from 36 of 75 PCR-positive BTM samples and 105 of 174 PCR-positive filter samples, and the isolates were serotyped. Cerro, Kentucky, Muenster, Anatum, and Newport were the most common serotypes. L. monocytogenes was isolated from 7.1% of the dairy operations, and the 1/2a complex was the most common serotype, followed by 1/2b and 4b (lineage 1). Shiga toxin genes were detected in enrichments from 15.2% of the BTM samples and from 51.0% of the filters by real-time PCR. In most cases, the cycle threshold values for the PCR indicated that toxigenic strains were not a major part of the enrichment populations. These data confirm those from earlier studies showing significant contamination of BTM by zoonotic bacterial pathogens and that the consumption of raw milk and raw milk products presents a health risk.

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Molecular Characteristics of Enterococcus faecalis and Enterococcus faecium from Bulk Tank Milk in Korea

Animals ◽

10.3390/ani11030661 ◽

2021 ◽

Vol 11 (3) ◽

pp. 661

Author(s):

Sunghyun Yoon ◽

Young Ju Lee

Keyword(s):

Antimicrobial Resistance ◽

Enterococcus Faecalis ◽

Enterococcus Faecium ◽

Virulence Genes ◽

Dairy Herd ◽

Molecular Characteristics ◽

Cross Contamination ◽

Bulk Tank Milk ◽

Milk Samples ◽

Bulk Tank

Enterococci are considered to be environmental mastitis-causing pathogens that can easily spread antimicrobial resistance or virulence genes via horizontal transfer. In this study, the molecular characteristics of enterococci from bulk tank milk were investigated to assess the importance of dairy herd management. A total of 338 enterococci (305 Enterococcus faecalis and 33 Enterococcus faecium) were isolated from 1584 batches of bulk tank milk samples from 396 farms affiliated with four dairy companies in Korea, and significant differences (40.6–79.7%) (p < 0.05) in the prevalence of enterococci were observed in the samples from different companies. Enterococci showed the highest resistance to tetracycline (TET) (73.4%), followed by doxycycline (DOX) (49.7%) and erythromycin (ERY) (46.2%), while two enterococci isolates showed resistance to vancomycin (VAN). Among 146 tetracycline (TET) and ERY-resistant enterococci, each 50 (19.4%) enterococci carried combination-resistance and transposon gene types erm(B) + tet(M) + IntTn and erm(B) + tet(L) + tet(M) + IntTn, respectively. The virulence genes such as ace (99.0%), efaA (97.7%), cad1 (95.7%), and gelE (85.9%) were highly conserved in E. faecalis and significantly predominated over E. faecium (p < 0.001). Our results indicate that pathogens from bulk tank milk can also become a reservoir for the dissemination of antimicrobial resistance and virulence factors through cross-contamination processes.

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