scholarly journals Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

2004 ◽  
Vol 3 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Andrea Serraino ◽  
Leonardo Alberghini ◽  
Maria Cristina Fontana ◽  
Cosima Annemüller ◽  
Christoph Lämmler ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Epidemiological Study ◽  
Bovine Mastitis ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Enterotoxin Genes ◽  
Bulk Tank

scholarly journals Characterization of Virulence Factors in Enterotoxin-Producing Staphylococcus Aureus From Bulk Tank Milk

2021 ◽  
Author(s):  
Hye-Ri Jung ◽  
Young Ju Lee
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Bulk Tank Milk ◽  
Genetic Characteristics ◽  
Enterotoxin Genes ◽  
High Prevalence ◽  
Bulk Tank

Abstract Background: Staphylococcus aureus, a persistent and chronic mastitis-causing pathogen, produces various virulence factors, including enterotoxins. This study analyzed the genetic characteristics of bovine mastitis-related virulence factors to evaluate potential pathogenesis in S. aureus isolated from bulk tank milk.Results: Among 93 S. aureus isolates from 396 dairy farms in six factories operated by three dairy companies in Korea, 40 (43.0%) isolates carried at least one or more enterotoxin genes and there were significant differences between factories within the same company (p < 0.05). Moreover, S. aureus carrying enterotoxin genes showed a higher prevalence in all virulence genes tested in this study except for pvl and lukM, which were not detected in any isolate, than the isolates without enterotoxin genes. In particular, the prevalence of six genes (hla, hlb, lukED, fnbA, clfA, and clfB) was significantly higher in S. aureus carrying enterotoxin genes than isolates without enterotoxin genes (p < 0.05). The most common multilocus sequence type (ST) of 40 enterotoxin-producing isolates was ST188, and all isolates of ST188 harbored the see gene. However, none of the isolates of ST1 and ST72 carried the see gene, and all isolates of ST1 carried the seh gene.Conclusions: Although S. aureus isolated from bulk tank milk, not from mastitis, had a high prevalence of enterotoxins and virulence factors simultaneously, posing a public health threat. Moreover, high enterotoxins in bulk tank milk may be reflected by poor hygiene; therefore, it is important to develop strong monitoring and sanitation programs to ensure that dairy factories produce hygienic milk.

scholarly journals Rapid Detection of Mycoplasma bovis, Staphylococcus aureus and Streptococcus agalactiae in Cattle Bulk Tank Milk in Cyprus and Relations with Somatic Cell Counts

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 841
Author(s):  
Maria Liapi ◽  
George Botsaris ◽  
Costas Arsenoglou ◽  
Nikolas Markantonis ◽  
Christodoulos Michael ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Somatic Cell ◽  
Real Time ◽  
Streptococcus Agalactiae ◽  
Mycoplasma Bovis ◽  
Bulk Tank Milk ◽  
Somatic Cell Counts ◽  
Milk Samples ◽  
Cell Counts ◽  
Bulk Tank

One hundred and seventy-seven (177) bulk tank milk samples were analyzed with a commercially available real-time polymerase chain reaction kit and 11 (6.21%), 41 (23.16%), and 58 (32.77%) tested positive for Mycoplasma bovis, Staphylococcus aureus, and Streptococcus agalactiae, respectively. Statistical analysis revealed a significant relationship between the presence of S. aureus and S. agalactiae. Enumeration of somatic cells was performed in the same samples by flow cytometry. The somatic cell counts were found higher in S. aureus and S. agalactiae positive samples. No association was found between M. bovis presence and somatic cells counts. Low internal assay control Ct values were found to be related with high somatic cell counts. Noticeably, this is the first report for the presence of M. bovis in Cyprus. Therefore, its presence was confirmed by bulk tank milk culture, conventional PCR, and next generation sequencing. Furthermore, M. bovis was typed with multilocus sequencing typing and was allocated to sequence type 29 (ST 29). Real-time PCR in bulk tank milk samples is a useful tool to detect mammary infections, especially for neglected pathogens such as M. bovis.

scholarly journals Mycoplasmal mastitis in dairy cows in the Moghan region of Ardabil State, Iran : short communication

2006 ◽  
Vol 77 (4) ◽  
Author(s):  
C. Ghazaei
Keyword(s):  
Dairy Cows ◽  
Short Communication ◽  
Bovine Mastitis ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Mycoplasma Bovis ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
The World ◽  
Bulk Tank

Mycoplasmas are an important and economically significant cause of mastitis in dairy cows in various parts of the world. The organisms are highly contagious, with the main reservoir of infection originating from cows with subclinical mastitis. In 1998 the 1st cases of bovine mastitis due to Mycoplasma bovis were diagnosed in Ardabil State, Iran. An investigation was carried out with the aim of establishing the extent of mycoplasma infections in dairy cows in Ardabil State. Milk samples obtained from 80 cows with clinical mastitis were cultured in the laboratory for the presence of mycoplasmas. Similarly, 48 bulk-tank milk samples were examined for the presence of mycoplasmas. A modified Hayflick broth was used to isolate the mycoplasmas and an immunoperoxidase test used for the species identification of the isolates. Mycoplasma bovis was isolated from 39 (48.75 %) of the clinical mastitis samples and from 48 of the bulk-tank milk samples tested. This indicated that mycoplasma udder infections were more prevalent in dairy cows in Ardabil State than previously thought.

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 Prevalence and distribution of multilocus sequence types of Staphylococcus aureus isolated from bulk tank milk and cows with mastitis in Pennsylvania

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248528
Author(s):  
Asha Thomas ◽  
Shubhada Chothe ◽  
Maurice Byukusenge ◽  
Tammy Mathews ◽  
Traci Pierre ◽  
...  
Keyword(s):  
Bovine Mastitis ◽  
Diagnostic Laboratory ◽  
Bulk Tank Milk ◽  
Enterotoxin Genes ◽  
Penn State ◽  
Bulk Tank ◽  
Mastitic Milk ◽  
Genotypic Characteristics ◽  
First Time ◽  
Sequence Types

A total of 163 S. aureus isolates; 113 from mastitic milk (MM) and 50 from bulk tank milk (BTM) (2008, 2013–2015) submitted for bacteriologic analysis at the Penn State Animal Diagnostic Laboratory were examined for their phenotypic and genotypic characteristics. Multi-locus sequence typing (MLST) analysis identified 16 unique sequence types (STs) which belonged to eight clonal complexes (CCs). Majority of the isolates were variants of CC97 (68.7%) and CC151 (25.1%). CC97 comprised of seven STs, of which two were new STs (ST3273, ST3274), while CC151 comprised of three STs of which ST3272 was identified for the first time. Several farms had more than one ST type that were either members of the same clonal complex or unrelated STs. On one farm, six different STs of both categories were seen over the years within the farm. It was observed that ST352 and ST151 were the two main clonal populations in cattle not only in Pennsylvania but also globally. Most isolates were susceptible to all the antibiotics evaluated. 6.7% of isolates showed resistance to vancomycin and penicillin. Two isolates of ST398 showed multidrug resistance (>3 antibiotics) against clindamycin, erythromycin, tetracycline, and penicillin. It was noted that 59 of 163 (36.2%) isolates encoded for enterotoxigenic genes. Enterotoxin genes seg/sei accounted for ~85% of enterotoxin positive isolates. Toxic shock syndrome gene tsst-1 alone was positive in two isolates (ST352, ST 2187). 97.5% of CC151 isolates were enterotoxin seg/sei positive. Most isolates were positive for lukED (95%) and lukAB (96.3%) leukotoxin genes. Bovine specific bi-component leucocidin lukMF’ was present in 54% of isolates. A prominent observation of this study was the explicit association of lukMF’ with lineages ST151 and ST352. In conclusion, the findings of the study, suggest that small number of S. aureus STs types (ST352, ST2187, ST3028, and ST151) are associated with majority of cases of bovine mastitis in Pennsylvania dairy farms. It was observed that one ST of S. aureus predominated in the herd and this ST can coexist with several other ST types of S. aureus strains. When STs were interpreted along with virulence, leucocidin genes and antimicrobial resistance, ST-variants allowed better interpretation of the S. aureus molecular epidemiologic findings specifically for tracing recurrence or persistence of infections in cow over time, among cows in the herd, and between herds in Pennsylvania.

Comparison of Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Bulk Tank Milk in Organic and Conventional Dairy Herds in the Midwestern United States and Denmark

2004 ◽  
Vol 67 (6) ◽  
pp. 1104-1110 ◽  
Author(s):  
K. SATO ◽  
T. W. BENNEDSGAARD ◽  
P. C. BARTLETT ◽  
R. J. ERSKINE ◽  
J. B. KANEENE
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Dairy Farms ◽  
Dairy Herds ◽  
Bulk Tank Milk ◽  
Aureus Isolate ◽  
Milk Samples ◽  
Bulk Tank

An observational study was conducted to compare the antimicrobial susceptibility patterns of Staphylococcus aureus isolated from bulk tank milk in organic and conventional dairy farms in Wisconsin, United States, and southern Jutland, Denmark. Bulk tank milk samples and data regarding management and production were collected from 30 organic and 30 conventional dairy farms in Wisconsin and 20 organic and 20 conventional dairy farms in Denmark. S. aureus isolates were tested for resistance against 15 antimicrobial agents by semiautomatic microbroth dilution methods in each country. Of the 118 bulk tank milk samples in Wisconsin, 71 samples (60%) yielded at least one S. aureus isolate, and a total of 331 isolates were collected. Of the 40 bulk tank milk samples from Denmark, 27 samples (55%) yielded at least one S. aureus isolate, and a total of 152 isolates were collected. Significant differences between organic and conventional dairies were detected only to ciprofloxacin in Wisconsin and avilamycin in Denmark. Significant differences (P &lt; 0.05) between the two countries were detected in nine antimicrobials. Denmark had a higher probability of having reduced susceptibility to ciprofloxacin and streptomycin (P = 0.015 and 0.003, respectively). Wisconsin isolates had a higher probability of having reduced susceptibility to seven other antimicrobial agents (bacitracin, gentamicin, kanamycin, penicillin, sulphamethoxazole, tetracycline, and trimethoprim). We found small differences between organic and conventional farm types in each country and larger differences between the two national agricultural systems.

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