scholarly journals Determination of the occurrence of plasmid virulence genes (spv) and antibiotic resistance of Salmonella strains isolated from raw milk

2018 ◽  
Vol 74 (1) ◽  
pp. 59-64 ◽  
Author(s):  
AGNIESZKA WISZNIEWSKA-ŁASZCZYCH ◽  
BARBARA ZDRODOWSKA ◽  
BEATA WYSOK ◽  
JOANNA SZTEYN ◽  
KATARZYNA LIEDTKE ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Raw Milk ◽  
Molecular Methods ◽  
Frequency Of Occurrence ◽  
Salmonella Spp ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Bulk Tank

The aim of the study was to measure the frequency of occurrence of Salmonella spp. in raw milk, to identify their serotype, as well as to determine their antibiotic resistance and the presence of Salmonella plasmid virulence (spv) genes. Out of 300 bulk tank milk samples, 5.3% were contaminated with Salmonella spp. All strains isolated belonged to the serovar S enteritidis, as confirmed by serotyping and molecular methods. The presence of spv genes was determined by PCR. Spv genes were present, in different patterns, in all strains tested. SpvA gene was present in all isolates (100%), spvB in 56.25%, spvC in 62.5%, spvD in 75%, and spvR in 56.25%. Antibiotic resistance was evaluated according to the NCCLS recommendations. All isolates were sensitive to ciprofloxacin (CIP), gentamicin (GE), and chloramphenicol (CH). Thirteen strains were resistant to ampicillin (AMP), 8 to erythromycin (E), 1 to doxycycline (DO), and 1 to tetracycline (TE). Different frequency of occurrence of the spv genes in Salmonella strains isolated from raw milk demonstrates their high adaptability. As many as 87.5% of isolates showed resistance to at least one of the antibiotics tested....

scholarly journals Prevalence, antibiotic resistance, virulence and genetic diversity of Staphylococcus aureus isolated from bulk tank milk samples of U.S. dairy herds

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kruthika Patel ◽  
Sandra M. Godden ◽  
Erin E. Royster ◽  
Brian A. Crooker ◽  
Timothy J. Johnson ◽  
...  
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Dairy Cows ◽  
Virulence Genes ◽  
Dairy Herds ◽  
Drug Resistant ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Bulk Tank

Abstract Background Colonization of dairy cows by Staphylococcus aureus (S. aureus), especially those which are multi-drug resistant and toxin producing, is a concern for animal health and well-being as well as public health. The objective of this study was to investigate the prevalence, antibiotic resistance, gene content and virulence determinants of S. aureus in bulk tank milk samples (BTM) from U.S. dairy herds. Results BTM samples were collected, once in winter and once in summer, from 189 U.S. dairy herds. Of 365 BTM samples cultured, the sample and herd prevalence of S. aureus in BTM was 46.6% (170 of 365 samples) and 62.4% (118 of 189 herds), respectively. Among a subset of 138 S. aureus isolates that were stored for further analysis, 124 were genome sequenced after being confirmed as S. aureus using phenotypic tests. The most commonly identified antimicrobial resistance-associated gene was norA (99.2%) and mecA gene responsible for methicillin resistance (MRSA) was identified in one isolate (0.8%). The most frequently detected putative virulence genes were aur (100%), hlgB (100%), hlgA, hlgC, hlb (99.2%), lukE (95.9%) and lukD (94.3%). In the 53 staphylococcal enterotoxin positive isolates, sen (37.9%), sem (35.5%), sei (35.5%) and seg (33.1%) were the most frequently detected enterotoxin genes. Among the 14 sequence types (ST) and 18 spa types identified, the most common was ST2187 (20.9%) and t529 (28.2%), respectively. The most predominant clone was CC97 (47.6%) followed by CC unknown (36.3%). The single MRSA isolate belonged to ST72-CC8, spa type t126 and was negative for the tst gene but harbored all the other virulence genes investigated. Conclusion Our findings indicated a high prevalence of S. aureus in BTM of U.S. dairy herds, with isolates showing little evidence of resistance to antibiotics commonly used to treat mastitis. However, isolates often carried genes for the various enterotoxins. This study identified predominant genetic clones. Despite lower prevalence, the presence of MRSA and multi-drug resistant strains in BTM poses a significant risk to animal and public health if their number were to increase in dairy environment. Therefore, it is necessary to continuously monitor the use of antibiotics in dairy cows.

scholarly journals Arcobacter spp. in raw milk from vending machines in Piedmont and occurrence of virulence genes in isolates

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Amaranta Traversa ◽  
Silvia Gallina ◽  
Francesca Martucci ◽  
Cvetelina Boteva ◽  
Elisa Baioni ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Foodborne Pathogen ◽  
Dairy Farms ◽  
Raw Milk ◽  
Human Consumption ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Vending Machines ◽  
Bulk Tank ◽  
P Type

Arcobacter spp. has been recognized as an emerging foodborne pathogen and a hazard to human health. In the dairy chain, it has been isolated from different sources, nevertheless data on Arcobacter occurrence in raw milk provided by vending machines are few. This study aimed to identify potentially pathogenic Arcobacter spp. in raw milk intended for human consumption sold through vending machines located in Piedmont. In an 8-month period, 37 raw milk samples were collected from 24 dairy farms: 12 (32,4%) were collected directly in farm from bulk tank milk and 25 (67,6%) from vending machines. Eight (21,6%) out of the 37 milk samples and 7 (29,2%) out of the 24 dairy farms were positive for Arcobacter spp. by culture examination. Four (16%) out of the 25 samples from vending machines and 4 (33,3%) out of the 12 samples from bulk tank milk were positive. All 8 isolates were identified as A. butzleri both by MALDI-TOF MS and multiplex end-point PCR. According to the detection of virulence genes, a total of four Patho-types were highlighted: 5 isolates in P-type 1 and only one isolate for each of the P-types 2-3-4. A. butzleri isolates carrying encoding virulence factors genes were isolated from raw milk intended for human consumption: these findings strengthen the compulsory consumption after boiling as required by current legislation and suggest the need of enlarging the analytical investigations to other microorganisms not yet included in the food safety criteria.

scholarly journals Haptoglobin and serum amyloid A in bulk tank milk in relation to raw milk quality

2009 ◽  
Vol 76 (4) ◽  
pp. 483-489 ◽  
Author(s):  
Maria Åkerstedt ◽  
Karin Persson Waller ◽  
Åse Sternesjö
Keyword(s):  
Whey Protein ◽  
Acute Phase ◽  
Serum Amyloid A ◽  
Acute Phase Proteins ◽  
Raw Milk ◽  
Milk Quality ◽  
Bulk Tank Milk ◽  
Amyloid A ◽  
Milk Samples ◽  
Bulk Tank

The aim of the present study was to evaluate relationships between the presence of the two major bovine acute phase proteins haptoglobin (Hp) and serum amyloid A (SAA) and raw milk quality parameters in bulk tank milk samples. Hp and SAA have been suggested as specific markers of mastitis but recently also as markers for raw milk quality. Since mastitis has detrimental effects on milk quality, it is important to investigate whether the presence of Hp or SAA indicates such changes in the composition and properties of the milk. Bulk tank milk samples (n=91) were analysed for Hp, SAA, total protein, casein, whey protein, proteolysis, fat, lactose, somatic cell count and coagulating properties. Samples with detectable levels of Hp had lower casein content, casein number and lactose content, but higher proteolysis than samples without Hp. Samples with detectable levels of SAA had lower casein number and lactose content, but higher whey protein content than samples without SAA. The presence of acute phase proteins in bulk tank milk is suggested as an indicator for unfavourable changes in the milk composition, e.g. protein quality, due to udder health disturbances, with economical implications for the dairy industry.

scholarly journals Biosensor assay for determination of haptoglobin in bovine milk

2006 ◽  
Vol 73 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Maria Åkerstedt ◽  
Lennart Björck ◽  
Karin Persson Waller ◽  
Åse Sternesjö
Keyword(s):  
Acute Phase ◽  
Limit Of Detection ◽  
Clinical Signs ◽  
Scientific Data ◽  
Technological Properties ◽  
Bulk Tank Milk ◽  
Biosensor Technology ◽  
Milk Samples ◽  
Bulk Tank

Despite more than 30 years of research into mastitis diagnostics, there are few alternatives to the somatic cell count (SCC) in practical use for identification of cows with subclinical mastitis. Mastitis is not only an animal welfare problem, but also affects the yield, composition and technological properties of milk. Hence, dairy cooperatives give farmers a premium quality payment to encourage low SCC although there is no clear scientific data defining the level of SCC in bulk tank milk that is associated with additional benefits in terms of milk quality. Recent research on alternative markers for inflammatory reactions in the lactating cow, e.g. in mastitis, includes investigations of the acute phase protein, haptoglobin (Hp). So far, the content of Hp in milk has mainly been studied in relation to mastitis diagnostics, with little attention given to its importance for milk composition and technological properties. At present, Hp in milk is measured using ELISA, but this technique is not suitable for routine large-scale analysis. In recent years, optical biosensor technology has been used for automated and rapid quantitative analysis of different components in milk, but so far not for analysis of acute phase proteins. The aim of the present study was to develop a rapid and sensitive biosensor method to determine Hp in milk. An affinity sensor assay based on the interaction between Hp and haemoglobin was developed using surface plasmon resonance (SPR) biosensor technology. The assay was used to analyse Hp in composite milk samples from cows without any clinical signs of mastitis and quarter milk samples with a weak to strong reaction in the California Mastitis Test (CMT). A commercial ELISA for determination of Hp in milk was used for comparison. The limit of detection (LOD) of the biosensor assay was determined as 1·1 mg/l. Within-assay and between-day variations were determined both with bulk tank milk spiked with human Hp and with composite milk samples containing bovine Hp. Coefficients of variation varied between 3·6 and 8·6% at concentrations between 4·0 and 12 mg/l, respectively. Agreement between the results obtained by the biosensor assay and the ELISA was satisfactory; however, the results obtained by the biosensor were generally lower than the results obtained by the ELISA. Possible explanations for this observation are discussed.

scholarly journals Climate conditions associated with the occurrence of antimicrobial and macrocyclic lactone residues in bulk tank milk

2017 ◽  
Vol 69 (2) ◽  
pp. 474-482
Author(s):  
L.C.A. Picinin ◽  
I.M. Toaldo ◽  
R.B. Hoff ◽  
F.N. Souza ◽  
M.O. Leite ◽  
...  
Keyword(s):  
Macrocyclic Lactone ◽  
Raw Milk ◽  
Maximum Temperature ◽  
Bulk Tank Milk ◽  
Climate Conditions ◽  
Average Temperature ◽  
Milk Samples ◽  
Antimicrobial Residues ◽  
Humidity Index ◽  
Bulk Tank

ABSTRACT The present study aimed to identify the climate condition parameters that are associated with the occurrence of antimicrobial and macrocyclic lactone residues in bulk tank milk using a multivariate principal components analysis (PCA). A total of 132 raw milk samples were collected at dairy farms in Minas Gerais State in Brazil and analyzed for 35 analytes, comprising macrocyclic lactones and antibacterials, using liquid chromatography coupled with mass spectrometry in tandem mode spectrometry. Of the 132 samples, 34 (25.76%) bulk tank milk samples were positive for at least one analyte. PCA showed that antimicrobial residues in bulk tank milk occurred less frequently on days with a higher average temperature, maximum temperature and temperature-humidity index. In contrast, relative humidity was inversely associated with antimicrobial residues in raw milk. The PCA showed that daily milk production was also related to macrocyclic lactone residues, while rainfall showed an inverse association. Thus, some climate conditions, such as average temperature, maximum temperature and temperature-humidity index, can predict the moments with lower risk of occurrence of antimicrobial residues in bulk tank milk, in contrast to relative humidity. Furthermore, the risk of macrocyclic lactone residues in bulk tank milk was higher in months with less rainfall.

scholarly journals Coagulase-negative staphylococci in ewe udder surface and raw milk samples

2021 ◽  
pp. 221-225
Author(s):  
Andualem Tonamo ◽  
István Komlósi ◽  
Flóra Mária Petróczki ◽  
Ferenc Peles
Keyword(s):  
16S Rrna Gene Sequencing ◽  
Bacterial Count ◽  
Raw Milk ◽  
Rrna Gene ◽  
Coagulase Negative Staphylococci ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Bulk Tank ◽  
Staphylococcus Simulans

Coagulase-negative staphylococci (CNS) are among the major causes of subclinical mastitis in dairy ewe flocks. This has a financially significant impact on the ewe dairy sector and consumer health. The determination of the bacterial count, particularly CNS, is critical in terms of the quantity and quality of ovine milk. Thus, the purpose of this study was to quantify the CNS count in the udder surface and raw milk samples of the ewe, in addition to identifying CNS strains (n=8) collected from udder surface and individual raw milk samples by 16S rRNA gene sequencing. A total of 164 samples of udder surface and raw milk originated from four sheep farms were tested. The obtained values were compared between the different farms. Furthermore, values during 2018 and 2019 in the case of Farm I were compared. Significantly higher (p<0.05) average count was observed in udder surface samples taken from Farm I (2.8±1.0 lg CFU/cm2) than that of Farm III samples (2.3±0.6 lg CFU/cm2). In the case of individual raw milk, the higher value was observed in samples derived from Farm III (3.5±0.9 lg CFU/mL), while the obtained value was significantly lower (p<0.05) in samples originated from Farm IV (1.8±0.4 lg CFU/mL). In the bulk tank milk samples, the highest mean value was 5.3±0.4 CFU/mL, and there was no significant (p>0.05) variation between farms. Coagulase-negative staphylococci counts were decreased to a certain extent in both sample types tested during 2019 except for individual raw milk derived from the Tsigai breed. The correlation between the mean CNS counts of udder surface and individual raw milk was very weak (r=0.048). Staphylococcus simulans, Staphylococcus auricularis, and Staphylococcus equorum were identified by molecular sequencing and Staphylococcus simulans were the most frequently identified CNS species. A higher CNS count of bulk tank milk than individual raw milk indicates possible contamination during milking and storage. Therefore, further studies are required to investigate the other sources of bulk tank milk contamination to improve the hygienic quality of milk.

scholarly journals Prevalence and Characterization of Pathogenic Bacteria in Bulk Tank Raw Milk, Thailand

2020 ◽  
Vol 17 (6) ◽  
pp. 588-599
Author(s):  
Chanida KUPRADIT ◽  
Sasidhorn INNOK ◽  
Jirayus WORARATPHOKA ◽  
Mariena KETUDAT-CAIRNS
Keyword(s):  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Milk Samples ◽  
Isolation And Characterization ◽  
Lack Of Information ◽  
Enterotoxin Genes ◽  
Bulk Tank

Although there are a number of raw milk collection centers in Nakhon Ratchasima, there is a lack of information with regard to the process of isolation and characterization of foodborne pathogens in raw milk. Therefore, the purpose of this research was to investigate the prevalence and characterization of foodborne pathogens, including Bacillus cereus, Escherichia coli, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus from 33 raw milk samples from 9 different raw milk collection centers located in 8 districts in Nakhon Ratchasima, Thailand. This study was conducted from January to March 2016. Results revealed that the contaminations of L. monocytogenes and Salmonella spp. were not detected in any of the raw milk samples tested. The prevalence of B. cereus, E. coli, and S. aureus in raw milk samples was found to be 9 % (10 - 2.0 ×104 CFU/ml), 42.4 and 54 % (85 - 2.7 ×104 CFU/ml), respectively. The distribution of virulence genes was tested in B. cereus and S. aureus using gene specific primers by polymerase chain reaction. Out of the 29 analyzed coagulase-positive S. aureus isolates, 27 isolates (93 %) were positive for eap gene amplification and 14 isolates (48 %) showed amplicon of eap gene and all 5 enterotoxin genes, including seG, seGV, seI, seIV, and seM genes. All 8 B. cereus isolates tested showed positive PCR result with enterotoxin FM (entFM) gene but they showed negative with hemolysin gene (hblA and hblD genes) amplifications. It was inferred from these findings that bulk tank milk is a potential source of S. aureus and B. cereus in milk.

scholarly journals Climate conditions associated with the occurrence of pyrethroid residues in bulk milk tank

2016 ◽  
Vol 68 (6) ◽  
pp. 1721-1726 ◽  
Author(s):  
L.C.A. Picinin ◽  
I.M. Toaldo ◽  
R.B. Hoff ◽  
F.N. Souza ◽  
M.O. Leite ◽  
...  
Keyword(s):  
Principal Component ◽  
Raw Milk ◽  
Electron Capture Detection ◽  
Bulk Tank Milk ◽  
Climate Conditions ◽  
Milk Samples ◽  
Bulk Milk ◽  
Humidity Index ◽  
Bulk Tank ◽  
Bulk Milk Tank

ABSTRACT The present study attempted to identify climate conditions that are associated with the occurrence of pyrethroid residues using a multivariate principal component analysis (PCA). A total of 132 raw milk samples were collected from dairy farms in Minas Gerais State - Brazil and analyzed for seven analytes using gas chromatography with electron capture detection. Of the 132 milk samples, pyrethroid residues were identified in 14 (10.6%) milk samples, of which 12 (9.1%) and two (1.5%) milk samples had the identification of cypermethrin and deltamethrin, respectively. From those samples, nine (6.8%) milk samples were regarded as non-compliant for cypermethrin with this analyte concentration above the maximum residue limits set by Brazilian legislation. A PCA assessing pyrethroid residues in bulk tank milk demonstrated that the average temperature and the Temperature-Humidity Index were associated with pyrethroids residues in bulk milk tank, although the relative humidity was inversely correlated. Thus, the data analysis indicated that the pyrethrid residues associated with some climate conditions can predict the moments with higher risk of occurrence of pyrethroid residues in bulk tank milk.

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

Animals ◽  
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.

scholarly journals Antibiotic Resistance And Plasmid Contents Of Salmonella Serotypes Isolated From Raw Milk

2007 ◽  
Vol 31 (1) ◽  
pp. 28-40
Author(s):  
Khilud K. Nazal
Keyword(s):  
Antibiotic Sensitivity ◽  
Raw Milk ◽  
Large Individual ◽  
Milk Samples ◽  
Inner Surface ◽  
Antibiotic Sensitivity Test ◽  
Bulk Tank ◽  
The Individual ◽  
The Relationship

This study lasted for eight months .The main objectives of the study wereto identify the main sources of raw milk pollution with Salmonella with aspecial emphasis on determination of their serotypes. The relationship betweentheir resistance to antibiotics and their plasmide contents were also studied.Six hundred raw milk samples collected randomly at weekly intervals where thefirst (300) samples were from the individual milk cans (50 Kg each) at theproducers homes in Abu-Ghraib village while the second (300) samples werecollected from the scale bulk tanks (2 tons) inside the milk reception andcollection center at the same village.In addition to that (200) swabs were taken from four different location (50swabs for each) namely: the teats, milkers hands, the inner surface of the milkcans and the sedimemts that were precipitated at the bottom of the scale bulktank.Data revealed that 5% of the milk cans and 7% of the scale bulk tank werecontaminated with Salmonella besides the percentage of the Salmonella isolatesfrom different swabs location were as 10% , 30% , 8% and 52% out of the teats,inner surface of milk cans, milker’s hands and sediments of the bulk tanksrespectively .Seven serotypes of Salmonella were identified from both milk samples andswabs including S. typhimurium 40 %, S. anatum 26.67%, S. Kottbus 13.33 %,S. infantis 6.67%, S. dublin6.67%, S. java 3.33% and S. typhi 3.33%.Antibiotic sensitivity test for different antibiotics revealed that mostSalmonella isolates were resistant to two antibiotics where (36.66%)of theisolates were resistant to Sulphamethazol, (16.66%)were resistant to tetracycline, (10%) were resistant to Streptomycin and (3.33%) were resistant to each ofChloramphenicol , Kanamycin and Ampicillin.The extraction of the DNA-plsmide revealed that seven out of ten isolatescontained large, individual plasmids size of (50-70) Killo Base (KB) while theothers three isolate were free from such plamid.

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