Biosensors for On-Farm Diagnosis of Mastitis

Abstract

Bovine mastitis is an inflammation of the mammary gland caused by a multitude of pathogens with devastating consequences for the dairy industry. Global annual losses are estimated to be around €30 bn and are caused by significant milk losses, poor milk quality, culling of chronically infected animals, and occasional deaths. Moreover, mastitis management routinely implies the administration of antibiotics to treat and prevent the disease which poses serious risks regarding the emergence of antibiotic resistance. Conventional diagnostic methods based on somatic cell counts (SCC) and plate-culture techniques are accurate in identifying the disease, the respective infectious agents and antibiotic resistant phenotypes. However, pressure exists to develop less lengthy approaches, capable of providing on-site information concerning the infection, and in this way, guide, and hasten the most adequate treatment. Biosensors are analytical tools that convert the presence of biological compounds into an electric signal. Benefitting from high signal-to-noise ratios and fast response times, when properly tuned, they can detect the presence of specific cells and cell markers with high sensitivity. In combination with microfluidics, they provide the means for development of automated and portable diagnostic devices. Still, while biosensors are growing at a fast pace in human diagnostics, applications for the veterinary market, and specifically, for the diagnosis of mastitis remain limited. This review highlights current approaches for mastitis diagnosis and describes the latest outcomes in biosensors and lab-on-chip devices with the potential to become real alternatives to standard practices. Focus is given to those technologies that, in a near future, will enable for an on-farm diagnosis of mastitis.

Multiple Bacteria Identification in the Point-of-Care: an Old Method Serving a New Approach

“…Microfluidic sample preparation and nucleic acid amplification units are currently in the prototyping stage to be integrated with the platform. With the fully integrated system, a measurement would be completed within a 4 h timeframe [2]. This technology can also be explored for diagnosis of other clinical applications, including hospital infections and antibiotic resistance genes.…”

“…Mastitis prevention and treatment consists in the regular administration of antibiotics, even though this entails high treatment costs and poor efficacy, also posing serious risks in the emergence of bacterial antimicrobial antibiotic resistance (AMR), which has become a serious public health concern. The standard diagnosis methods for bacterial identification involve microbial culture which, although accurate in identifying disease, the respective infectious agents and antibiotic resistant phenotypes is a slow process and demands specialized facilities and personnel [2]. It also should be noted that sample collection, conditioning, and transportation to centralized laboratories delays test results and treatment decisions.…”

“…In comparison to microbial culture, POC PCR-based systems are expected to bring improvements in terms of time of analysis, sample volume, and the ability to analyze multiple targets in the same assay. While bacterial culturing-based detection of pathogens requires sample incubation for at least 18 h [6], result times can be significantly reduced to a couple of hours using fully integrated systems that comprise miniaturized sample preparation and amplification units [2].…”

Prevalence, Antimicrobial Resistance Profiles, Virulence and Enterotoxins-Determinant Genes of MRSA Isolated from Subclinical Bovine Mastitis in Egypt

“…Staphylococcus aureus is a significant public health bacterial pathogen, causing mastitis in dairy animals including cattle, buffalo, sheep and goats [1]. S. aureus mastitis and its produced toxins lead to great economic losses in dairy farms due to: (1) reduction in the milk production, (2) alteration in the composition and quality of the produced milk, (3) the need to discard the produced milk, (4) early culling of infected animals, and (5) high cost of treatment and control [2]. Resistance of S. aureus to several antimicrobials complicates the treatment of these pathogenic bacteria, which is considered an increasing challenge.…”

Antimicrobial Susceptibility of Staphylococcus aureus, Streptococcus agalactiae, and Escherichia coli Isolated from Mastitic Dairy Cattle in Ukraine

“…Although Escherichia coli , Staphylococcus aureus , and Streptococcus agalactiae are considered some of the main mastitis-causing pathogens, many other bacterial species can be implicated [ 1 , 2 , 3 , 4 ]. Due to the bacterial diversity associated with bovine mastitis, and the fact that pathogen identification is not frequently performed for mastitic dairy cattle, antimicrobials with a broad spectrum of activity against both gram-negative and gram-positive organisms are routinely used in dairy medicine [ 1 , 5 ]. As a result of decades-long usage of antimicrobials to date, bacterial resistance is an increasing concern in, and beyond, veterinary medicine [ 2 , 6 , 7 ].…”