Prevalence of Subclinical Mastitis and Distribution of Pathogens in Dairy Farms of Rubavu and Nyabihu Districts, Rwanda.
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ABSTRACT:
SUBMITTER: Mpatswenumugabo JP
PROVIDER: S-EPMC5535704 | biostudies-other | 2017
REPOSITORIES: biostudies-other
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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:Whole-genome sequencing was carried out on 30 Staphylococcus (S.) aureus isolates from dairy cows with subclinical mastitis from all five provinces of Rwanda. Twenty-five of the isolates produced enough sequence to be analyzed using core genome multilocus sequence typing (cg-MLST). The isolates group into three main clusters. The largest cluster contain isolates of sequence type (ST) 152 (n = 6) and the closely related ST1633 (n = 2). These sequence types have previously mainly been encountered in humans. The isolates of the second-largest cluster belong to ST5477 (n = 5),so far exclusively isolated from cows in Rwanda. The third cluster consists of isolates of ST97 (n = 4), which is a well-known bovine-adapted sequence type. These three clusters were all widespread over the country. Isolates of the usually human-adapted sequence types 1 (n = 2) and 5 (n= 1) were found and a single isolate of ST2430, previously found among humans in Africa. Finally, four isolates of novel sequence types were found: ST7108 (n = 2), ST7109 (n = 1), and ST7110 (n = 1). The blaZ penicillin resistance gene was found in 84% of the isolates and was in all cases corroborated by phenotypic resistance determination. Five (20%) of the isolates carried a tetracycline resistance gene, tet(K) or tetM, and three of these five also displayed phenotypic resistance while two isolates carried a tetM-gene but were yet tetracycline susceptible. Seven (28%) isolates carried the dfrG gene conferring resistance to trimethoprim. Four of these isolates indeed were resistant to trimethoprim while three isolates were sensitive. The str gene conferring resistance to aminoglycosides was found in three isolates; however, none of these displayed resistance to gentamycin. Our data revealed a high diversity of the sequence types of S. aureus isolates from cows with subclinical mastitis in Rwanda. Two major clusters of ST97 and ST5477 are likely to be bovine adapted and cause mastitis while the third cluster of ST152 usually have been found in humans and may signify a recent transmission of these types from human to cows, for example from hand milking. The high prevalence of this sequence type among dairy cows may pose zoonotic threat. The sequence types were widely distributed without any geographic correlation. Penicillin resistance, the most common type of resistance with a prevalence over 80%, but also tetracycline and trimethoprim resistance were displayed by several isolates.
| S-EPMC8637448 | 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: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:Data is also available from http://bugs.sgul.ac.uk/E-BUGS-76
2009-08-07 | E-BUGS-76 | biostudies-arrayexpress
Project description:A longitudinal observational study was carried out from January 2020 to July 2021 to assess the impact of subclinical mastitis (SCM) on reproductive performance and its association with uterine health of crossbred dairy cows. The California Mastitis Test (CMT) and cytobrush technique were used to screen subclinical mastitis and subclinical endometritis, respectively. Milk samples positive for subclinical mastitis were subjected to bacteriological analysis. Data from 84 clinically healthy cows collected and analyzed. The present study revealed a prevalence of subclinical mastitis of 51.2% (43 of 84). The mean days from calving to first service interval were significantly longer in subclinical mastitis positive cows than negative (control) cows (120.51 ± 24.5 and 85.15 ± 28.3, respectively) (P < 0.05). The mean number of services per conception was significantly higher in positive cows (2.51 ± 0.83) than in negative cows (1.59 ± 0.81) (P < 0.05). Lower conception and pregnancy rates at first services were observed in subclinical mastitis cows. Risk factors analysis revealed that prevalence of subclinical mastitis significantly differed with the parity and body condition score (P < 0.05). The current study revealed that subclinical mastitis was significantly and directly associated with subclinical endometritis (P < 0.05). Subclinical mastitis significantly decreased (P = 0.000) progesterone concentrations and increased (P = 0.001) the cortisol concentrations. Staphylococcus aureus were the most predominant bacterial isolates from subclinical mastitic milk, followed by coagulase negative staphylococci (CNS) and streptococci. This study concludes a high prevalence of subclinical mastitis caused by Staphylococcus aureus could inflict harmful effects on reproductive performance of dairy cows, emphasizing the relevance of mastitis control programs in dairy farms.
| S-EPMC10250799 | biostudies-literature
Project description:BackgroundThe dairy industry has undergone substantial structural changes as intensive farming has developed during recent decades. Mastitis continues to be the most common production disease of dairy cows. Nationwide surveys of mastitis prevalence are useful in monitoring udder health of dairy herds and to study the impact of structural changes on the dairy industry. This survey on bovine subclinical mastitis was the first based on cow composite milk somatic cell count (SCC) data from the Finnish national health monitoring and milk recording database. A cow with composite milk SCC ≥200,000 cells/ml in at least one of the four test milkings during the year was considered to have subclinical mastitis and a cow with composite milk SCC ≥200,000 cells/ml in three or in all four test milkings during the year to have chronic subclinical mastitis. The aim of the study was to determine the prevalence of subclinical mastitis and chronic subclinical mastitis in Finland in 1991, 2001 and 2010 and to investigate cow and herd factors associated with elevated SCC.ResultsPrevalence of subclinical mastitis in Finland decreased over recent decades from 22.3% (1991) and 20.1% (2001) to 19.0% (2010). Prevalence of chronic subclinical mastitis was 20.4% in 1991, 15.5% in 2001 and 16.1% in 2010. The most significant cow and herd factors associated with subclinical mastitis or high milk SCC were increasing parity, Holstein breed, free-stalls with an automatic milking system and organic production. Milk SCC were highest from July to September. Main factors associated with chronic mastitis were increasing parity and Holstein breed.ConclusionsPrevalence of subclinical mastitis in Finland decreased over recent decades, the greatest change taking place during the first decade of the study. Prevalence of chronic subclinical mastitis significantly decreased from 1991. The most significant factors associated with both types of mastitis were increasing parity and Holstein breed, and for subclinical mastitis also free-stalls with automatic milking. National surveys on mastitis prevalence should be carried out at regular intervals to monitor udder health of dairy cows and to study the impact of the ongoing structural changes in the dairy industry to enable interventions related to udder health to be made when needed.
| S-EPMC5397772 | 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:Subclinical mastitis is a persistent problem in dairy farms worldwide. Environmental Escherichia coli is the bacterium predominantly responsible for this condition. In Thailand, subclinical mastitis in dairy cows is usually treated with various antibiotics, which could lead to antibiotic resistance in bacteria. E. coli is also a reservoir of many antibiotic resistance genes, which can be conveyed to other bacteria. In this study, the presence of E. coli in milk and water samples was reported, among which enteropathogenic E. coli was predominant, followed by enteroaggregative E. coli and enterohemorrhagic E. coli, which was found only in milk samples. Twenty-one patterns of antibiotic resistance were identified in this study. Ampicillin- and carbenicillin-resistant E. coli was the most common among the bacterial isolates from water samples. Meanwhile, resistance to ampicillin, carbenicillin, and sulfamethoxazole-trimethoprim was the pattern found most commonly in the E. coli from milk samples. Notably, only the E. coli from water samples possessed ESBL phenotype and carried antibiotic resistance genes, blaTEM and blaCMY-2. This indicates that pathogenic E. coli in dairy farms is also exposed to antibiotics and could potentially transfer these genes to other pathogenic bacteria under certain conditions.
| S-EPMC5472034 | biostudies-literature
Project description:Staphylococcus aureus mastitis in dairy sheep ranges from subclinical mastitis to lethal gangrenous mastitis. Neither the S. aureus virulence factors nor the host-factors or the epidemiological events contributing to the different outcomes are known. In a field study in a dairy sheep farm over 21 months, 16 natural isolates of S. aureus were collected from six subclinical mastitis cases, one lethal gangrenous mastitis case, nasal carriage from eight ewes and one isolate from ambient air in the milking room. A genomic comparison of two strains, one responsible for subclinical mastitis and one for lethal gangrenous mastitis, was performed using multi-strain DNA microarrays. Multiple typing techniques (pulsed-field-gel-electrophoresis, multiple-locus variable-number, single-nucleotide polymorphisms, randomly amplified polymorphic DNA, spa typing and sas typing) were used to characterise the remaining isolates and to follow the persistence of the gangrenous isolate in ewes' nares. Our results showed that the two strains were genetically closely related and they shared 3 615 identical predicted open reading frames. However, the gangrenous mastitis isolate carried variant versions of several genes (sdrD, clfA-B, sasA, sasB, sasD, sasI and splE) and was missing fibrinogen binding protein B (fnbB) and a prophage. The typing results showed that this gangrenous strain emerged after the initial subclinical mastitis screening, but then persisted in the flock in the nares of four ewes. Although we cannot dismiss the role of host susceptibility in the clinical events in this flock, our data support the hypothesis that S. aureus populations had evolved in the sheep flock and that S. aureus genetic variations could have contributed to enhanced virulence.
| S-EPMC2733328 | biostudies-literature