The Dissemination of a Single Staphylococcusaureus Strain, Spa-t2873, as the Predominant Cause of Bovine Mastitis in Israeli Dairy Farms.
Ontology highlight
ABSTRACT:
SUBMITTER: Shwimmer A
PROVIDER: S-EPMC9317514 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Staphylococcus aureus is one of the most important contagious bacteria causing subclinical bovine mastitis. This bacterial infection is commonly identified by determine the pathogen in bovine milk samples through conventional technique including coagulase test. However, this test has several disadvantages as low sensitivity, risk of biohazard, cost expensive, and limited preparation especially in local area.Aim of this study was to compare and assess the screening method, Mannitol fermentation test (Mannitol salt agar [MSA]), and deoxyribonuclease (DNase) test, for S. aureus identification in milk samples.A total of 224 subclinical bovine mastitis milk samples were collected from four provinces of Thailand and determined S. aureus using conventional method and also subjected to the screening test, MSA and DNase test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) among both tests were analyzed and compared to the tube coagulase test (TCT), as reference method. Immunological test by latex agglutination and molecular assay by determined spa gene were also used to identify and differentiate S. aureus.A total of 130 staphylococci were isolated by selective media, Gram-stain, and catalase test. The number of S. aureus which identified using TCT, MSA and DNase test were 32, 102, and 74 isolates, respectively. All TCT results were correlated to results of latex agglutination and spa gene which were 32 S. aureus. MSA showed 100% sensitivity, 28.57% specificity, 31.37% PPV, and 100% NPV, whereas DNase showed 53.13% sensitivity, 41.84% specificity, 22.97% PPV, and 73.21% NPV. DNase test showed higher specificity value than MSA but the test presented 26.79% false negative results whereas no false-negative result from MSA when comparing to TCT.MSA had a tendency to be a good preference for screening S. aureus because of its high sensitivity and NPV. The result from this study will improve a choice to use a screening test to diagnose S. aureus of veterinary field for prompt disease controlling and effective treatment.
| S-EPMC5553136 | biostudies-other
Project description:BackgroundStaphylococcus aureus is one of the main microorganisms that causes bovine mastitis, and its well-known virulence characteristics and interactions with the environment are used to aid the design of more efficient therapies.ObjectivesTo determine whether the virulence traits, such as antibiotic resistance and biofilm-forming and internalization abilities, of S. aureus isolated from bovine mastitis are related to dairy production system types.MethodsThe study was performed in the Mexican states of Guanajuato and Michoacan. Semi-intensive dairy farms (SIDFs) and family dairy farms (FDFs) (454 and 363 cows, respectively) were included. The 194 milk samples from mastitis affected quarters were collected and 92 strains of S. aureus were isolated and identified by biochemical and molecular tests. Antibiotic resistance, biofilm and internalization assays were performed on 30 randomly selected isolated strains to determine virulence traits, and these strains were equally allocated to the 2 dairy production systems.ResultsAll 30 selected strains displayed a high degree of resistance (50%-91.7%) to the antibiotics tested, but no significant difference was found between SIDF and FDF isolates. S. aureus strains from SIDFs had an average biofilm forming capacity of up to 36% (18.9%-53.1%), while S. aureus strains from FDFs registered an average of up to 53% (31.5%-77.8%) (p > 0.05). Internalization assays revealed a higher frequency of internalization capacity for strains isolated from FDFs (33.3%) than for those isolated from SIDFs (6.7%) (p > 0.05). fnbpA gen was detected in 46.6% of FDF strains and 33.3% of SIDF strains, and this difference was significant (p < 0.05).ConclusionsOur findings show that the virulence traits of S. aureus isolates analyzed in this study, depend significantly on several factors, such as phenotype, genotype, and environmental conditions, which are significantly related to dairy production system type and daily management practices.
| S-EPMC7533384 | biostudies-literature
Project description:Bovine mastitis continues to be a complex disease associated with significant economic loss in dairy industries worldwide. The incidence rate of subclinical mastitis (IRSCM) can show substantial variation among different farms; however, the milk microbiota, which have a direct influence on bovine mammary gland health, have never been associated with the IRSCM. Here, we aimed to use high-throughput DNA sequencing to describe the milk microbiota from two dairy farms with different IRSCMs and to identify the predominant mastitis pathogens along with commensal or potential beneficial bacteria. Our study showed that Klebsiella, Escherichia-Shigella, and Streptococcus were the mastitis-causing pathogens in farm A (with a lower IRSCM), while Streptococcus and Corynebacterium were the mastitis-causing pathogens in farm B (with a higher IRSCM). The relative abundance of all pathogens in farm B (22.12%) was higher than that in farm A (9.82%). However, the genus Bacillus was more prevalent in farm A. These results may be helpful for explaining the lower IRSCM in farm A. Additionally, the gut-associated genera Prevotella, Ruminococcus, Bacteroides, Rikenella, and Alistipes were prevalent in all milk samples, suggesting gut bacteria can be one of the predominant microbial contamination in milk. Moreover, Listeria monocytogenes (a foodborne pathogen) was found to be prevalent in farm A, even though it had a lower IRSCM. Overall, our study showed complex diversity between the milk microbiota in dairy farms with different IRSCMs. This suggests that variation in IRSCMs may not only be determined by the heterogeneity and prevalence of mastitis-causing pathogens but also be associated with potential beneficial bacteria. In the future, milk microbiota should be considered in bovine mammary gland health management. This would be helpful for both the establishment of a targeted mastitis control system and the control of the safety and quality of dairy products.
| S-EPMC6232673 | biostudies-literature
Project description:Staphylococcus aureus encodes many proteins that act as virulence factors, leading to a variety of diseases, including mastitis in cows. Among these virulence factors, SpA, ClfA, ClfB, FnbA, and FnbB are important for the ability of S. aureus to adhere to and invade host cells as well as to evade host immune responses. The interaction between these S. aureus surface proteins and human immunoglobulin G and fibrinogen that are coupled to latex particles is utilized to induce latex agglutination reactions, which are used widely in diagnostic kits for confirmation of presumptive S. aureus isolates. In this study, the Staphaurex latex agglutination test was performed on a collection of confirmed bovine mastitis S. aureus isolates. Notably, 54% (43/79 isolates) of these isolates exhibited latex agglutination-negative phenotypes (Staphaurex-negative result). To gain insights into the reasons for the high frequency of Staphaurex-negative bovine mastitis S. aureus isolates, the spa, clfA, clfB, fnbA, and fnbB genes were examined. Specific genetic changes in spa, clfA, and fnbA, as well as a loss of fnbB, which may impair SpA, ClfA, FnbA, and FnbB functions in latex agglutination reactions, were detected in Staphaurex-negative S. aureus isolates. The genetic changes included a premature stop codon in the spa gene, leading to a truncated SpA protein that is unable to participate in S. aureus cell-mediated agglutination of latex particles. In addition, clfA and fnbA genetic polymorphisms were detected that were linked to ClfA and FnbA amino acid changes that may significantly reduce fibrinogen-binding activity. The genetic variations in these S. aureus isolates might also have implications for their bovine mastitis virulence capacity.
| S-EPMC3043514 | biostudies-literature
Project description:Mastitis imposes considerable and recurring economic losses on the dairy industry worldwide. The main objective of this study was to estimate herd-level costs incurred by expenditures and production losses associated with mastitis on Canadian dairy farms in 2015, based on producer reports. Previously, published mastitis economic frameworks were used to develop an economic model with the most important cost components. Components investigated were divided between clinical mastitis (CM), subclinical mastitis (SCM), and other costs components (i.e., preventive measures and product quality). A questionnaire was mailed to 374 dairy producers randomly selected from the (Canadian National Dairy Study 2015) to collect data on these costs components, and 145 dairy producers returned a completed questionnaire. For each herd, costs due to the different mastitis-related components were computed by applying the values reported by the dairy producer to the developed economic model. Then, for each herd, a proportion of the costs attributable to a specific component was computed by dividing absolute costs for this component by total herd mastitis-related costs. Median self-reported CM incidence was 19 cases/100 cow-year and mean self-reported bulk milk somatic cell count was 184,000 cells/mL. Most producers reported using post-milking teat disinfection (97%) and dry cow therapy (93%), and a substantial proportion of producers reported using pre-milking teat disinfection (79%) and wearing gloves during milking (77%). Mastitis costs were substantial (662 CAD per milking cow per year for a typical Canadian dairy farm), with a large portion of the costs (48%) being attributed to SCM, and 34 and 15% due to CM and implementation of preventive measures, respectively. For SCM, the two most important cost components were the subsequent milk yield reduction and culling (72 and 25% of SCM costs, respectively). For CM, first, second, and third most important cost components were culling (48% of CM costs), milk yield reduction following the CM events (34%), and discarded milk (11%), respectively. This study is the first since 1990 to investigate costs of mastitis in Canada. The model developed in the current study can be used to compute mastitis costs at the herd and national level in Canada.
| S-EPMC5961536 | biostudies-literature
Project description:E. coli is one of the major significant pathogens causing mastitis, the most complex and costly diseases in the dairy industry worldwide. Present study was undertaken to isolate, detect the virulence factors, phylogroup, antimicrobial susceptibility and antimicrobial resistance genes in E. coli from cows with clinical mastitis. A total of 68 milk samples comprising 53 from clinical mastitis and 15 from apparently healthy cattle were collected from four different established dairy farms in Bangladesh. E. coli was isolated from the milk samples and identified by PCR targeting malB gene and sequencing of 16S rRNA gene. E. coli isolates were screened by PCR for the detection of major virulence genes (stx, eae and cdt) of diarrheagenic E. coli followed by phylogenetic grouping. Antimicrobial susceptibility of the E. coli isolates was determined by disk diffusion test and E. coli showing resistance was further screened for the presence of antimicrobial resistance genes. E. coli was isolated from 35.8% of the mastitis milk samples but none from the apparently healthy cattle milk. All the E. coli isolates were negative for stx, eae and cdt genes and belonged to the phylogenetic groups A and B1 which comprising of commensal E. coli. Antibiotic sensitivity testing revealed 84.2% (16/19) of the isolates as multidrug resistant. Highest resistance was observed against amoxicillin (94.5%) followed by ampicillin (89.5%) and tetracycline (89.5%). E. coli were found resistant against all the classes of antimicrobials used at the farm level. Tetracycline resistance gene (tetA) was detected in 100% of the tetracycline resistant E. coli and blaTEM-1 was present in 38.9% of the E. coli isolates. Findings of this study indicate a potential threat of developing antimicrobial resistance in commensal E. coli and their association with clinical mastitis. Occurrence of multidrug resistant E. coli might be responsible for the failure of antibiotic therapies in clinical mastitis as well as pose potential threat of transmitting and development of antibiotic resistance in human.
| S-EPMC8568714 | biostudies-literature
Project description:The aim of this study was to investigate the potential risk factors for clinical and subclinical mastitis in smallholder dairy farms in Brazil. A prospective, repeated cross-sectional study was carried out between May 2018 and June 2019 on 10 smallholder dairy farms. Potential risk factors for subclinical and clinical mastitis at the herd and cow level were recorded through interviewing the owner and by observation. A combination of clinical udder examination and the Tamis (screened mug with a dark base) test (Tadabras Indústria e Comércio de Produtos Agrovetereinário LTDA, Bragrança Paulista, SP, Brazil) were applied to observe clinical mastitis, and the California Mastitis Test (Tadabras Indústria e Comércio de Produtos Agrovetereinário LTDA, Bragrança Paulista, SP, Brazil) was used to determine subclinical mastitis. A total of 4567 quarters were tested, 107 (2.3%) had clinical mastitis, while 1519 (33.2%) had subclinical mastitis. At the cow level, clinical mastitis risk was highest in mid-lactation (50-150 days in milk) with OR 2.62 with 95% confidence interval (CI) of 1.03-6.67, while subclinical mastitis was highest in late lactation (> 150 days in milk) with OR 2.74 (95% CI 2.05-3.63) and lower in primiparous (OR 0.54, 95% CI 0.41-0.71) than multiparous cows. At the herd level, using dry-cow treatment (OR 4.23, 95% CI 1.42-12.62) was associated with an increased risk of clinical mastitis. Milking clinical (OR 0.37, 95% CI 0.24-0.56) and subclinical cases last (OR 0.21, 95% CI 0.09-0.47) and cleaning the milking parlor regularly (OR 0.27, 95% CI 0.15-0.46) had decreased odds for subclinical mastitis, while herds with optimized feed had greater odds (OR 9.11, 95% CI 2.59-31.9). Prevalence of clinical mastitis was at its lowest at the first visit in June/July and highest at the last visit in April/June (OR 3.81, 95% CI 1.93-7.52). Subclinical mastitis also presented increased odds in the last visit (OR 2.62, 95% CI 2.0-3.36). This study has identified some risk factors for mastitis on smallholder farms but further research on more farms across more areas of Brazil is required to develop a targeted mastitis control program for smallholder farms.
| S-EPMC8300378 | biostudies-literature
Project description:Attitudes toward practical dairy cow welfare issues were evaluated based on a questionnaire answered by 500 dairy farm workers and 27 veterinary practitioners. Primarily, the effect of demographic characteristics on attitudes toward cattle welfare was tested. Professionally, five themes were identified: effect of welfare awareness on productivity, knowledge of cattle's senses and social structure, effects of man-animal interactions on milk yield, pain perception and prevention, and knowledge transfer from veterinary practitioners to farm workers. Farms with a higher welfare awareness score also had higher annual milk yield, with an annual mean difference of 1000 L of milk per cow between farms with higher and lower awareness scores. Veterinary practitioners showed high awareness of cows' social structure, senses, and pain perception. Farm workers were aware of the influence of man-animal interactions during milking and stress effects on milk yield, and the possible effect of man's behavior on heifers and cows. Practitioners and farm workers had different views regarding pain perception, mostly involving mutilation procedures. All veterinary practitioners advocated the use of pain alleviation in painful procedures, but only some of them instructed the farm workers to administer it. The survey results emphasize the variation in welfare knowledge and practical applications across farms, and the interest of both the animals and their managers to improve applied knowledge of best practice.
| S-EPMC7912428 | biostudies-literature
Project description:A cross-sectional study was conducted from May 2016 to January 2017 in Rubavu and Nyabihu districts, Western Rwanda, aiming at estimating the prevalence of subclinical mastitis (SCM) and identifying its causative bacteria. Management practices and milking procedures were recorded through a questionnaire. 123 crossbreed milking cows from 13 dairy farms were randomly selected and screened for SCM using California Mastitis Test (CMT). Composite CMT positive milk samples were processed for bacterial isolation and identification. The overall SCM prevalence at cow level was 50.4%. 68 bacterial isolates were identified by morphological and biochemical characteristics. They included, Coagulase Negative Staphylococci (51.5%), Staphylococcus aureus (20.6%), Streptococcus species (10.3%), Bacillus species (10.3%), Streptococcus agalactiae (5.8%), and Escherichia coli (1.5%). About 67.1% of the farmers checked for mastitis; of these, 58.9% relied on clinical signs and only 6.8% screened with CMT. Only 5.5% and 2.7% of the farmers tried to control mastitis using dry cow therapy and teat dips, respectively. Thus, to reduce the prevalence of SCM, farmers in the study area need to be trained on good milking practices, including regular use of teat dips, application of dry cow therapy, and SCM screening. This will improve their sales and their financial status.
| S-EPMC5535704 | biostudies-other
Project description:The lytic efficacy of bacteriophages against Staphylococcus aureus isolates from bovine milk was investigated in vitro, regarding possible applications in the therapy of udder inflammation caused by bacterial infections (mastitis). The host range of sequenced, lytic bacteriophages was determined against a collection of 92 Staphylococcus (S.) aureus isolates. The isolates originated from quarter foremilk samples of clinical and subclinical mastitis cases. A spot test and a subsequent plaque assay were used to determine the phage host range. According to their host range, propagation and storage properties, three phages, STA1.ST29, EB1.ST11, and EB1.ST27, were selected for preparing a bacteriophage mixture (1:1:1), which was examined for its lytic activity against S. aureus in pasteurized and raw milk. It was found that almost two thirds of the isolates could be lysed by at least one of the tested phages. The bacteriophage mixture was able to reduce the S. aureus germ density in pasteurized milk and its reduction ability was maintained in raw milk, with only a moderate decrease compared to the results in pasteurized milk. The significant reduction ability of the phage mixture in raw milk promotes further in vivo investigation.
| S-EPMC7151712 | biostudies-literature