Efecto del conservante azidiol sobre el diagnóstico de bacterias causantes de mastitis bovina.

Abstract

Azidiol is a chemical compound with bacteriostatic effect recommended for preserving raw milk samples, which will be used for compositional and hygienic-sanitary analyses. However, its use to preserve milk samples which will be used in the diagnosis of mastitis-causing pathogens, has not been clearly documented. The objective of this study was to evaluate the effect of azidiol on the microbiological culture detection of mastitis-causing bacteria. Milk samples, with and without azidiol, were inoculated with two bacterial concentrations from each strain included (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Escherichia coli). The results demonstrated that bacteria of Streptococcus and Staphylococcus genera, were isolated from the samples containing azidiol 24 hours after the inoculation with both bacterial concentrations, although no culture exceeded the number colony forming units inoculated at the beginning. S. agalactiae was the only bacterium that could be isolated at 48 and 72 hours of incubation of the samples inoculated with both bacterial concentrations and that contained the preservative, while E. coli was not isolated from any sample with azidiol. In the control samples (without preservative) the four strains were isolated during the three incubation times. In conclusion, the milk samples preserved with azidiol can be used on the diagnosis of mastitis-causing Gram-positive bacteria within 24 hours after the collection of milk samples, but this is not recommended neither for preserving milk samples which will be processed after this time, nor in the diagnosis of the mastitis-causing Gram-negative bacteria.

Keywords:

análisis bacteriológico

Escherichia coli

preservación de muestras

refrigeración

Staphylococcus

Streptococcus

bacteriological analysis

Escherichia coli

refrigeration

samples preservation

Staphylococcus

Streptococcus

References

 Almeida, T.; Neves, R.; Arnhold, E. et al. Efeito da temperatura e do tempo de armazenamento de amostras de leite cru nos resultados das análises eletrônicas.Arquivo Brasileiro de Medicina Veterinária e Zootecnia, v.68, n.5, p.1316-1324, 2016.

 Benda, J. The effect of some preservatives on natural microflora in milk samples.Veterinarni Medicina, v.40, n.11, 1995.

 Bradley, A.; Leach, K.; Breen, J. et al. Survey of the incidence and aetiology of mastitis on dairy farms in England and Wales. The Veterinary Record, v.160, n.8, p.253-257, 2007.

 Britten, A. The role of diagnostic microbiology in mastitis control programs. The

 Veterinary Clinics of North America. Food Animal Practice, v.28, n.2, p.187-202, 2012.

 Cassoli, L.; Machado, P.; Codebella, A. Métodos de conservação de amostras de leite para determinação da contagem bacteriana total por citometria de fluxo. Revista Brasileira de Zootecnia, v.39, n.2, p.434-439, 2010.

 De Garnica, M.L.; Santos, J.; Gonzalo, C. Influence of storage and preservation on microbiological quality of silo ovine milk. Journal of Dairy Science, v.94, n.4, p.1922- 1927, 2011.

 Elizondo, J.; Aldunate, A.; Ezcurra, P. et al. Efficiency of the proportion of azidiol on preservation in ewe’s milk samples for analysis. Food Control, v.18, n.3, p.185-190, 2007.

 Fu, Y.; Zhou, E.; Liu, Z. et al. Staphylococcus aureus and Escherichia coli elicit different innate immune responses from bovine mammary epithelial cells. Veterinary Immunology and Immunopathology, v.155, n.4, p.245-252, 2013.

 Kossaibati, M.; Esslemont, R. The costs of production diseases in dairy herds in England. Veterinary Journal, v.154, n.1, p.41-51, 1997.

 Leite, M. Fatores intereferentes na análise eletrônica da qualidade do leite cru conservado com azidiol liquido, azidiol comprimido e bronopol. Minas Gerais, Brasil: Universidade de Minas Gerais, 2006. Tese (Doutorado em Ciência Animal).

 Llopis, M.; Marugán, M.; Marugón, M. et al. Effect of storage and preservation of milk samples on the response of microbial inhibitor tests. The Journal of Dairy Research, v.80, n.4, p.475-484, 2013.

 Martins, M.; Nicolau, E.; Mesquita, A. et al. Bronopol and azidiol chemicals: time and temperature influence in the total bacterial count of raw milk. Ciência Animal Brasileira, v.10, n.2, p.627-633, 2009.

 National Mastitis Council. Microbiological procedures for the diagnosis of bovine udder infection and determination of milk quality. 4th edition. Verona, USA, 2004. 47p.

 Neder, V.; Signorini, M.; Cuatrin, A. et al. Prevalencia de bacterias patógenas de Mastitis bovina en leche de tanque de frío y evaluación de medios de cultivo para el recuento y la identificación de Staphylococcus aureus. Revista FAVE - Ciencias Veterinarias, v.13, n.1-2, p.21-28, 2014.

 Neidhardt, F.; Ingraham, J.; Schaechter, M. Physiology of the bacterial cell. A molecular approach. Sunderland, MA, USA: Sinauer associates, 1990. 507p.

 Olde, R.; Barkema, H.; Kelton, D. et al. Incidence rate of clinical mastitis on Canadian dairy farms. Journal of Dairy Science, v.91, n.4, p.1366-1377, 2008.

 Peixoto, R.; Araújo, R.; Peixoto, L. et al. Indirect diagnostic tests for the detection of subclinical mastitis in dairy goats experimentally infected with Staphylococcus aureus. Ciência Rural, v.46, n.7, p.1217-1222, 2016.

 Philpot, N.; Nickerson, S. Ganando la lucha contra la mastitis. 1.ed. Naperville, USA, 2000. 192p.

 Shim, E.; Shanks, R.; Morin, D. Milk loss and treatment costs associated with two treatment protocols for clinical mastitis in dairy cows. Journal of Dairy Science, v.87, n.8, p.2702-2708, 2004.

 Sierra, D.; Sánchez, A.; Contreras, A. et al. Short communication: effect of storage and preservation on total bacterial counts determined by automated flow cytometry in bulk tank goat milk. Journal of Dairy Science, v.92, n.10, p.4841-4845, 2009.

 Souza, G.; Faria, C.; Rios, R. Efeitos da temperatura e do tempo de armazenamento sobre a contagem total de bactérias em amostras de leite cru conservadas com azidiol. In: Congreso Nacional de Laticínios, 2006, Minas Gerais - Brasil. Memoria, v.61, p.358-361.