scholarly journals A mathematical model of Staphylococcus aureus control in dairy herds

2002 ◽  
Vol 129 (2) ◽  
pp. 397-416 ◽  
Author(s):  
R. N. ZADOKS ◽  
H. G. ALLORE ◽  
T. J. HAGENAARS ◽  
H. W. BARKEMA ◽  
Y. H. SCHUKKEN
Keyword(s):  
Staphylococcus Aureus ◽  
Current Knowledge ◽  
Threshold Value ◽  
Subclinical Mastitis ◽  
Equation Model ◽  
Reproductive Number ◽  
Dairy Herds ◽  
Model Parameters ◽  
Model Treatment ◽  
Prior Infection

An ordinary differential equation model was developed to simulate dynamics of Staphylococcus aureus mastitis. Data to estimate model parameters were obtained from an 18-month observational study in three commercial dairy herds. A deterministic simulation model was constructed to estimate values of the basic (R0) and effective (Rt) reproductive number in each herd, and to examine the effect of management on mastitis control. In all herds R0 was below the threshold value 1, indicating control of contagious transmission. Rt was higher than R0 because recovered individuals were more susceptible to infection than individuals without prior infection history. Disease dynamics in two herds were well described by the model. Treatment of subclinical mastitis and prevention of influx of infected individuals contributed to decrease of S. aureus prevalence. For one herd, the model failed to mimic field observations. Explanations for the discrepancy are given in a discussion of current knowledge and model assumptions.

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

scholarly journals Characterization of Staphylococcus aureus Isolates from Buffalo, Bovine, Ovine, and Caprine Milk Samples Collected in Rio de Janeiro State, Brazil

2007 ◽  
Vol 73 (12) ◽  
pp. 3845-3849 ◽  
Author(s):  
Marta Aires-de-Sousa ◽  
Carlos E. S. R. Parente ◽  
Olney Vieira-da-Motta ◽  
Isabel C. F. Bonna ◽  
Denise A. Silva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Rio De Janeiro ◽  
Animal Species ◽  
Subclinical Mastitis ◽  
Molecular Techniques ◽  
Dairy Herds ◽  
Milk Samples ◽  
Caprine Milk ◽  
Major Clone ◽  
Janeiro State

ABSTRACT Eighty-four staphylococcal isolates were obtained from milk samples from cows, sheep, goats, and buffalo with subclinical mastitis and from colonization samples from ostriches. The animals were hosted in 18 small dairy herds and an ostrich breeding located in 10 municipalities of the state of Rio de Janeiro, Brazil. Thirty isolates were identified as Staphylococcus aureus by biochemical and molecular techniques and were comparatively characterized by phenotypic and genotypic methods. The molecular characterization by pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) revealed five clonal types (PFGE A, spa type t359, sequence type 747 [ST747]; PFGE B, spa type t1180, ST750; PFGE C, spa type t605, ST126; PFGE D, spa type t127, ST751; and PFGE F, spa type t002, ST5). None of the isolates harbored the Panton-Valentine leukocidin or exfoliative toxin D gene. The detection of major clone A (in 63% of the isolates) in different herds, among all animal species studied, and in infection and colonization samples evidenced its geographical spread among Rio de Janeiro State and no host preference among the animal species. Comparison with S. aureus from a human origin suggested that all but one clone found in the present study might be animal specific.

scholarly journals Determination of Haemaglutinin and Gene Encoding Fibronectin Binding Proteins Staphylococcus aureus Isolated from Dairy Milk Cows

2015 ◽  
Vol 16 (2) ◽  
pp. 88
Author(s):  
Feny Prabawati Pratomo ◽  
Siti Isrina Oktavia Salasia ◽  
Syarifudin Tato
Keyword(s):  
Staphylococcus Aureus ◽  
Binding Proteins ◽  
Subclinical Mastitis ◽  
Dairy Herds ◽  
Gene Encoding ◽  
Milk Cows ◽  
Quality Of Milk ◽  
Dairy Milk

Staphylococcus aureus is a major pathogen causing clinical and subclinical mastitis in dairy milk cows. Themastitis has immense economical impacts, where it reduces of the quantity and quality of milk production.The aims of the research were to analyse haemaglutinin and gene encoding fbronectin binding proteins.Nineteen Staphylococcus aureus isolates used in the present study were isolated from dairy milk cows fromYogyakarta, Solo, Boyolali and Sumedang. The haemagluitinin of S. aureus were determined based onhaemaglutination reaction to erythrocytes of rabbit. Detection of gene encoding fbronectin binding proteinscould be performed with specifc primers using polymerase chain reaction (PCR). The results of studiesshowed that most of S. aureus (78,95%) expressed haemaglutinin based on their ability to aglutinate rabbiterythrocytes. Analysis of gene encoding fbronectin binding proteins of S. aureus revealed gene fnbA withsize of approximately 1300 bp for 57,89% isolates, gene fnbB with size of approximately 900 bp for 31,58%isolates and both of gene fnbA and fnbB could be detected for 31,58% isolates. The characters of S. aureusbased on haemaglutinin, gene fnbA and fnbB of the present study could be used as an information to controlof S. aureus infection in dairy herds.

scholarly journals Malonyl-proteome profiles of Staphylococcus aureus reveal lysine malonylation modification in enzymes involved in energy metabolism

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanan Shi ◽  
Jingjing Zhu ◽  
Yan Xu ◽  
Xiaozhao Tang ◽  
Zushun Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Energy Metabolism ◽  
Active Sites ◽  
Current Knowledge ◽  
Tricarboxylic Acid Cycle ◽  
Protein A ◽  
Pentose Phosphate ◽  
Post Translational Modification ◽  
Bacterial Physiology ◽  
Dihydrolipoyl Dehydrogenase

Abstract Background Protein lysine malonylation, a novel post-translational modification (PTM), has been recently linked with energy metabolism in bacteria. Staphylococcus aureus is the third most important foodborne pathogen worldwide. Nonetheless, substrates and biological roles of malonylation are still poorly understood in this pathogen. Results Using anti-malonyl-lysine antibody enrichment and high-resolution LC-MS/MS analysis, 440 lysine-malonylated sites were identified in 281 proteins of S. aureus strain. The frequency of valine in position − 1 and alanine at + 2 and + 4 positions was high. KEGG pathway analysis showed that six categories were highly enriched, including ribosome, glycolysis/gluconeogenesis, pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA), valine, leucine, isoleucine degradation, and aminoacyl-tRNA biosynthesis. In total, 31 malonylated sites in S. aureus shared homology with lysine-malonylated sites previously identified in E. coli, indicating malonylated proteins are highly conserved among bacteria. Key rate-limiting enzymes in central carbon metabolic pathways were also found to be malonylated in S. aureus, namely pyruvate kinase (PYK), 6-phosphofructokinase, phosphoglycerate kinase, dihydrolipoyl dehydrogenase, and F1F0-ATP synthase. Notably, malonylation sites were found at or near protein active sites, including KH domain protein, thioredoxin, alanine dehydrogenase (ALD), dihydrolipoyl dehydrogenase (LpdA), pyruvate oxidase CidC, and catabolite control protein A (CcpA), thus suggesting that lysine malonylation may affect the activity of such enzymes. Conclusions Data presented herein expand the current knowledge on lysine malonylation in prokaryotes and indicate the potential roles of protein malonylation in bacterial physiology and metabolism.

scholarly journals Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

2021 ◽  
Vol 11 (2) ◽  
pp. 541
Author(s):  
Katarzyna Grudlewska-Buda ◽  
Krzysztof Skowron ◽  
Ewa Wałecka-Zacharska ◽  
Natalia Wiktorczyk-Kapischke ◽  
Jarosław Bystroń ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Economic Problem ◽  
Cow Milk ◽  
P Value ◽  
Dairy Herds ◽  
E Coli ◽  
Bonferroni Test

Mastitis is a major economic problem in dairy herds, as it might decrease fertility, and negatively affect milk quality and milk yield. Out of over 150 bacterial species responsible for the udder inflammation, Escherichia coli is one of the most notable. This study aimed to assess antimicrobial susceptibility, resistance to dipping agents and biofilm formation of 150 E. coli strains isolated from milk of cows with subclinical and clinical mastitis. The strains came from three dairy herds located in Northern and Central Poland. The statistical analyses were performed with post-hoc Bonferroni test and chi-square test (including Yates correction). The data with a p value of <0.05 were considered significant. We found that the tested strains were mostly sensitive to antimicrobials and dipping agents. It was shown that 37.33% and 4.67% of strains were resistant and moderately resistant to at least one antimicrobial agent, respectively. No extended-spectrum beta-lactamases (ESBL)-producing E. coli were detected. The majority of strains did not possess the ability to form biofilm or formed a weak biofilm. The strong biofilm formers were found only among strains derived from cows with subclinical mastitis. The lowest bacteria number was noted for subclinical mastitis cows’ strains, after stabilization with iodine (3.77 log CFU × cm−2) and chlorhexidine (3.96 log CFU × cm−2) treatment. In the present study, no statistically significant differences in susceptibility to antibiotics and the ability to form biofilm were found among the strains isolated from cows with subclinical and clinical mastitis. Despite this, infections in dairy herds should be monitored. Limiting the spread of bacteria and characterizing the most common etiological factors would allow proper treatment.

scholarly journals Molecular characterization of virulence factors in Staphylococcus aureus isolated from bovine subclinical mastitis in central Ethiopia

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Desiye Tesfaye Tegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cows ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Animal Health ◽  
Subclinical Mastitis ◽  
Biochemical Tests ◽  
Milk Samples ◽  
Lactating Dairy Cows ◽  
Genomic Study

Abstract Purpose Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in the central part of Ethiopia. Methods A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by the California mastitis test (CMT) for bovine subclinical mastitis. One hundred thirty CMT-positive milk samples were collected and transported to the laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results From a total of 265 lactating dairy cows screened, 49% (n = 130) were positive for bovine subclinical mastitis. One hundred thirty mastitic milk samples were subjected to bacterial culturing, and one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA, and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion The presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.

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