Logo do repositório
 
Logótipo do projeto
Projeto de investigação

Sem título

Apenas metadados

Financiador

Organização

Autores

Publicações

Portable “lab-on-chip” platform for bovine mastitis diagnosis in raw milk
Publication . Duarte, Carla Margarida Pinheiro Cardoso; Bexiga, José Ricardo Dias; Freitas, Paulo Jorge Peixeiro de
Bovine mastitis is an economic burden for farmers mostly because of decreased milk yield, premature culling and cost of veterinary treatments. The identification of mastitis pathogens is of major importance in order for adequate control measures to be taken, to reduce the risk of appearance of chronic infections, and to target antimicrobial therapy. The aim of this study was to develop and validate a sensitive method for magnetic detection of Streptococcus agalactiae, Streptococcus uberis, Staphylococcus aureus and Staphylococcus epidermidis in raw milk samples. Mastitic milk samples were collected aseptically from 81 cows with subclinical mastitis, from 12 Portuguese dairy farms. Ninety one quarter milk samples were selected based on bacteriological results. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidics sample handling. This immunological recognition was able to detect bacterial presence above 100 cfu/ ml, depending on antibody and targeted bacteria. Comparison with PCR results showed sensitivities of 73% and 41%, specificity values of 25% and 57%, and PPV values of 35% and 54% for magnetic identification of streptococci species with an anti-S. agalactiae antibody and an anti-GB Streptococcus antibody, respectively. Regarding staphylococci species, the sensitivity values found were of 57.1% and 79.3%, specificities of 75% and 50%, and PPV values of 40% and 95.8% for magnetic identification with an anti-S. aureus antibody and an anti-Staphylococcus spp. antibody, respectively. Both bacterial genus studies translated a fair expectation for a “cow-side” use application, making this integrated platform of potential use after further improvements for fast bacteriological infection screening. Some constraints are described as well as the method´s limitations in bacterial quantification.
2016-07-15Tese de doutoramento Acesso aberto Ver mais

Unidades organizacionais

Descrição

Palavras-chave

Contribuidores

Financiadores

Entidade financiadora

Fundação para a Ciência e a Tecnologia

Programa de financiamento

3599-PPCDT

Número da atribuição

PEst-OE/CTM/LA0024/2013

ID