Relationship between total bacteria counts and somatic cell counts from mammary quarters infected by mastitis pathogens/Relacao entre contagem total de bacterias e contagem de celulas somaticas de quartos mamarios infectados por patogenos da mastite

• Published in: Ciência rural 2012-04, Vol.42 (4), p.691-696
• Main Authors: Lopes, Joao Emidio Ferreira, Jr, Lange, Carla Cristine, Briton, Maria Aparecida Vasconcelos Paiva, Santos, Fabiana Ribeiro, Silva, Marco Aurelio Souto, de Moraes, Luciano Castro Dutra, de Souza, Guilherme Nunes
• Format: Article
• Language: eng ; spa
• Subjects: Bacteria; bacteria shedding; contagem de células somáticas; liberação de bactérias; Mastitis; mastitis pathogens; patógenos da mastite; somatic cell count; Staphylococcus aureus infections
• ISSN: 0103-8478; 1678-4596
• DOI: 10.1590/S0103-84782012000400019

This study was conducted to establish the relationship between somatic cell count (SCC) and bacterial shedding from mammary quarters according to mastitis pathogens. Milk samples from 638 mammary quarters were examined for mastitis pathogens, SCC and total bacterial count (TBC). The raw data of SCC and TBC were used to perform descriptive statistics. The significance of the arithmetic mean differences between SCC and TBC according to bacteriological examination results was determined by a two-tailed unpaired t-test. Pearson and Spearman's correlations were done with logarithmic data and linear regression analyses. The geometric means of the bacteriological examination results were (cells [mL.sup.-1]; CFU [mL.sup.-1]): no growth (52,000; 12,000), coagulase-negative staphylococci (85,000; 17,000), Staphylococcus aureus (587,000; 77,000); other streptococci (432,000; 108,000) and Streptococcus agalactiae (1,572,000; 333,000). The Pearson and Spearman's correlations between SCC and TBC were higher than 0.60 for all mastitis pathogens. The regression analyses slopes showed different increase in TBC with the same increase in SCC according to mastitis pathogens. The slope for S. agalactiae (0.542) was higher than that for other mastitis pathogens. The results suggest that the intensity of inflammatory process was associated with number of mastitis pathogens shedding from the mammary gland. Key words: mastitis pathogens, somatic cell count, bacteria shedding Este estudo foi realizado com objetivo de estabelecer a relacao entre contagem de celulas somaticas (CCS) e a liberacao de bacterias de quartos mamarios de acordo com os patogenos da mastite. Amostras de leite de 638 quartos mamarios foram examinadas para identificacao dos patogenos da mastite, CCS e contagem total de bacterias (CTB). Estatisticas descritivas foram utilizadas para avaliar os dados brutos de CCS e CTB. A diferenca entre medias para CCS e CTB de acordo com os resultados dos exames bacteriologicos foi avaliada pelo teste T para amostras independentes. Foram realizadas a correlacao de Pearson, de Spearman e regressao linear com os dados transformados. As medias geometricas de acordo com os resultados dos exames bacteriologicos foram (celulas [mL.sup.-1]; UFC [mL.sup.-1]): sem crescimento (52.000; 12.000), estafilococos coagulase negativo (85.000; 17.000), Staphylococcus aureus (587.000; 77000); outros estreptococus (432.000; 108.000) e Streptococcus agalactiae (1.572.000; 333.000). A correlacao de