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Staphylococcus aureus (S. aureus), the bacteria most frequently associated with mastitis in cattle and buffalo, has a large number of genes connected to antibiotic resistance. The objective of the current research was to determine the erythromycin and macrolide resistance of S. aureus isolated from mastitic milk of cattle and buffalo, particularly resistance-related genes (ermA, ermB, ermC, ermT, and msrA). Therefore, 150 dairy cattle and 135 dairy buffalo bred by small farmers in various governorates of Egypt (Cairo, Giza, Kalyobia, Fayoum, and Kafr El-Sheikh) provided a total of 285 milk samples. Inspection revealed that a total of 34 (22.7%) and 36 (26.7%) milk samples from cattle and buffalo, respectively, had clinical mastitis. With a total recovery of 31 (44.3%) S. aureus isolates. Bacterial isolation and identification of S. aureus verified the isolation and identification of 14 (41.2%) and 17 (47.2%) S. aureus isolates from cattle and buffalo, respectively. Utilizing a TaqMan probe-based real-time PCR method that targets the nuc gene, all S. aureus isolates were verified. In instances of bovine mastitis in India and Kenya, conventional PCR targeting the nuc gene, followed by DNA sequencing and phylogenetic analysis, revealed a high homology (100%) with that of S. aureus strains isolated from milk. For the tested genes, the prevalence of resistant strains was 9.6% (ermA), 64.5% (ermB), 70.9% (ermC), 19.3% (ermT), and 9.6%. (msrA). Therefore, effective control measures should be adopted to stop the spread of drug-resistant S. aureus to humans. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to evaluate and quantify the different factors affecting the costs of mastitis in cattle, to quantify the annual and monthly financial losses attributed to mastitis, and to estimate production losses using average linear scores found on The Dairy Herd Improvement Association somatic cell count (SCC) sheets and bulk tank SCC per lactation number. Materials and Methods: All data (bovine mastitis-associated costs and expenditures in Egyptian dairy herds) were analyzed using SPSS/PCT, 2001. A partial budget technique using spreadsheet software and the general linear model procedure was used to analyze the productive and financial measures. Results: Mastitis was present in 57.1% of cows (240/420), while clinical mastitis (CM) was present in 19% of them (80/420). The geometric mean of SCC/ml in bulk tank milk samples of 150 cattle dairy farms was 556.3×103. The annual subclinical mastitis (SCM)-related economic loss was 21,933,258.6 LE, and the two most important cost components were the subsequent decrease in milk production and quality premium losses (93% and 7% of SCM costs, respectively). The quality premium loss was 1,369,602.1 LE. On the other hand, the annual economic loss due to decreased milk production as a result of SCM was 20,563,656.5 LE. The total cost of 80 CM cases, including the failure and preventive costs, was 1,196,871.4 LE, including 1,169,150.4 LE failure costs (106,336.0 LE in direct costs and 1,062,814.4 LE in indirect costs) and 27,721.0 LE preventive costs. The average cost per CM case was 28,760.9 LE, including veterinary time and consultation fees of 250.0 LE (1%), labor 562.5 LE (2%), premature culling 736,000.0 LE (77%), decreased milk production 4085.18 LE (13.7%), discarded milk 185.3 LE (1%), and drugs and treatments 328.9 LE (1%). The total costs of CM (expenditures) extra control and preventive measures, including the diagnosis of CM for 80 cows annually in 20 Egyptian dairy farms were 27,721.0 LE, representing 346.5 LE or 1% of the total cost of CM cases. The cost of monitoring and diagnostic measures was 8635.2 LE, representing 107.9 LE or 1% of the total cost of a case of CM. Conclusion: The method used for cost estimation, in this study, is highly adaptable to individual cattle farms and had a major role in assessing specific control and management measures. The concepts described in this paper help to improve our understanding of the full economic impact of clinical and subclinical mastitis in cattle in Egypt. Assessing the economic losses from mastitis to determine the economic costs and losses occurring in Egyptian dairy farms is critical for encouraging farmers to acknowledge the scale of the problem and implement effective management practices aimed at improving mastitis control and reducing the associated costs. [ABSTRACT FROM AUTHOR]

Objective: The current investigation was designed to point out the prevalence of multidrug-resistant Streptococcus spp. causing acute clinical mastitis and their pattern of antibiotic resistance in dairy cows. Materials and methods: Milk was sampled from 128 dairy cows with 191 infected quarters during the period from August 2017 to December 2018. Bacterial species were isolated from the milk samples and identified based on colony morphology and biochemical tests. Multiplex PCR was done for confirmatory detection of the Streptococcus spp. isolates. Results: The chief isolation percentages, from the sampled milk, were Escherichia coli (26%), then Staphylococcus aureus (23%), and Streptococcus dysagalactiae (23%), then Streptococcus agalactiae (20.1%), and finally coagulase-negative Staphylococci (7.7%). In confirmed PCR streptococci isolates, the antibiotic resistance genes have been detected, including macrolides antibiotic resistance genes (ermB and mefA genes), lincosamides antibiotic resistance genes (linB gene), and tetracycline resistance genes (tetM and tetO genes). Age, parity number, cleaning of bedding materials, cleaning of milking facilities, and utensils and udder cleaning practice were significant risk factors for multidrug-resistant streptococcal mastitis in dairy cows. Conclusion: The results of this study explored the phenotypic and genotypic traits of Streptococcus spp. which constitute a usual cause of acute clinical mastitis in dairy cows. The ermB, mefA, tetM, and tetO antibiotic-resistant genes were identified in streptococci isolates from dairy cows' milk with acute clinical mastitis, indicating a public health hazard. Thus, veterinary clinical breakpoints are needed to improve surveillance data, improve the hygiene regimen on the farms, and promote the wise use of antimicrobials. [ABSTRACT FROM AUTHOR]

Background and Aim: Bovine mastitis is the costliest prevalent disease in the dairy sector due to the limitations of conventional treatments. Zinc oxide nanoparticles (ZnO-NPs) have been regarded as safe and economical antibacterial candidates against several microorganisms, but the tendency of these particles to aggregate is a major barrier to their application. This study aimed to enhance the antibacterial efficiency of ZnO-NPs against some bacterial agents, causing bovine mastitis. Materials and Methods: A total of 24 milk samples out of 300 cases from Nubaria farm, Beheira Governorate, Egypt, were collected from cows with clinical mastitis. ZnO-NPs were fabricated by a sonochemical method using starch as a capping agent and by an auto-combustion reaction using glycine as a fuel. The two preparations of synthesized ZnO-NPs at different concentrations were assessed for their antimicrobial activities in vitro against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae isolated from milk of affected cows. Results: Sonochemically synthesized capped ZnO-NPs were dispersed and non-agglomerated in comparison with aggregated uncapped ZnO-NPs prepared by an auto-combustion reaction. Capped dispersed ZnO-NPs showed higher antibacterial activity against S. aureus, E. coli, and K. pneumoniae than particles synthesized by the auto-combustion reaction at same concentrations. However, the zone of inhibition for dispersed and agglomerated ZnO-NPs was concentration-dependent. In addition, Gram-positive S. aureus exhibited higher resistance to ZnO-NPs synthesized by both methods than Gram-negative E. coli and K. pneumoniae. Conclusion: Dispersed, non-agglomerated ZnO-NPs fabricated using starch as a capping agent under sonochemical irradiation could potentially be regarded as highly effective and inexpensive antimicrobial agents against S. aureus, E. coli, and K. pneumoniae for the management of bovine mastitis. [ABSTRACT FROM AUTHOR]

This study was carried-out to determine the main factors affecting the economic and productive efficiency of dairy farms and how the improvement of such factors increases the farms efficiency under Egyptian conditions. Reproductive, productive and economic data of 78 clinically mastitic Holstein cows from 3 private dairy farms in Dakahlia province in north delta of Egypt were used in this study. Cows were classified according to production into high and low producing cows, and according to parity into primiparous (1st lactation) and multiparous (2nd or higher lactation). Season of calving was also classified into winter, summer, spring and autumn by 3-months interval. The study revealed that, the clinical mastitis incidence as well as the dairy farms productive, reproductive and economic efficiency were significantly affected by cow production, parity and season of production. Also, mastitis reduced the dairy farms productive and economic efficiency due to the reduction of milk yield, milk returns and increasing of treatment costs. [ABSTRACT FROM AUTHOR]