Species identification and antimicrobial susceptibility profile of bacteria causing subclinical mastitis in buffalo / Identificação de espécies e perfil de susceptibilidade antimicrobiano de bactérias causadoras de mastite subclínica em búfalos

Microorganisms causing subclinical mastitis in water buffalo were isolated from 20 buffalo milk samples at four dairy farms located in central region of São Paulo State, Brazil, through testing of somatic cell count (SCC), standard plate count (SPC), biochemical, PCR assays and antimicrobial profile. The SCC showed average of 721,000 cells/mL in the milk, indicating the presence of subclinical mastitis. The overall average for SPC was 1.8 x 104 CFU/mL. The microorganism most frequently isolation according to biochemical tests were: Staphylococcus epidermidis (17%), Staphylococcus aureus (15%), Bacillus spp. (14%), Acinetobacter spp. (12.5%); with intermediate frequency: Pseudomonas aeruginosa (9.5%); Shigella flexneri (7.0%), Streptococcus spp. (5.5%), Corynebacterium spp. (5.0%), Escherichia coli (4.5%), Serratia marcescens (4.0%), Stenotrophomonas maltophilia (4.0%), and low incidence: Klebsiella rhinoscleromatis (0.5%), Klebsiella ozaenae (0.5%), Tatumella ptyseos (0.5%), Enterobacter cloacae (0.5%). The molecular analysis indicated that samples positive by culture method of the genera Staphylococcus, Streptococcus and E. coli were positive by PCR. Para S. aureus and S. epidermidis the highest percentages of observed sensitivity were gentamicin (100%) and vancomycin (100%); for the genus Streptococcus to gentamicin and oxacillin and E. coli to Ampicilin. These findings may help in the control and treatment of subclinical mastitis in buffaloes and contribute to improving the efficiency and quality of the milk produced.(AU)

Microrganismos causadores de mastites subclínicas em búfalas foram isolados desde 20 amostras de leite de búfalos de quatro granjas leiteiras localizadas na região central do Estado de São Paulo, Brasil, através dos testes contagem de células somáticas (CCS), contagem padrão em placas (CPP), provas bioquímicas, reações de PCR e perfil antimicrobiano. A CCS apresentou uma mediana de 721.000 cel/mL no leite, indicando presença de mastite subclínica. A média geral de CPP foi de 1,8x104 UFC/mL. Os microrganismos com maior frequência de isolamento segundo os testes bioquímicos foram: Staphylococcus epidermidis (17%), Staphylococcus aureus (15%), Bacillus spp. (14%), Acinetobacter spp. (12,5%); frequência intermediaria: Pseudomonas aeruginosa (9,5%); Shigella flexneri (7,0%), Streptococcus spp. (5,5%), Corynebacterium spp. (5,0%), Escherichia coli (4,5%), Serratia marcescens (4,0%), Stenotrophomonas maltophilia (4,0%), e baixa incidência: Klebsiella rhinoscleromatis (0,5%), Klebsiella ozaenae (0,5%), Tatumella ptyseos (0,5%), Enterobacter cloacae (0,5%). A análise molecular indicou que as amostras positivas pelo método de cultura dos gêneros Staphylococcus, Streptococcus e Escherichia coli foram positivas por PCR. Para S. aureus e S. epidermidis os maiores percentuais de sensibilidade observados foram gentamicina (100%) e vancomicina (100%); para o gênero Streptococcus à gentamicina e oxacilina e para E. coli à ampicilina. Este resultados podem ajudar no controle e tratamento da mastite subclínica em búfalos e contribuir para melhorar a eficiência e qualidade do leite produzido.(AU)

Microorganisms in the rumen and reticulum of buffalo (Bubalus bubalis) fed two different feeding systems.

BACKGROUND: The community of microorganisms in the rumen and reticulum is influenced by feeding as well as the species and geographical distribution of ruminant animals. Bacteria, methanogenic archaea and ciliate protozoa existing in the rumen and reticulum were evaluated by real-time polymerase chain reaction and light microscopy in buffalo in two feeding systems, grazing and feedlot. RESULTS: No significant differences were observed in the total concentrations of bacteria/mL and archaea between rumen and reticulum, and between pasture and feedlots, or interactions between variables. However, the largest density of bacteria and smallest density of archaea was observed in the rumen of grazing animals. The total ciliates protozoa community was higher in grazing buffalo than those in the feedlot on a concentrated diet. There were significant interactions between location in the gastrointestinal tract (rumen vs reticulum) and types of diets (grazing vs feedlot) in the composition of ciliates. CONCLUSIONS: Our data showed differences in the microbial community of the rumen and reticulum between grazing and feedlot feeding systems demonstrating relevant changes in the microorganism:host relationship existing on rumen-reticulum ecosystem.

Analysis of rumen methanogen diversity in water buffaloes (Bubalus bubalis) under three different diets.

The water buffalo (Bubalus bubalis) is a prominent livestock species for the production of milk and meat in many countries. We investigated the diversity of rumen methanogens in Mediterranean water buffaloes maintained in Brazil under different diets: corn silage, grazing pasture, or sugar cane. A total of 467 clones were isolated from three methanogen 16S rRNA gene clone libraries that each represented a distinct feed type. The 467 clones were assigned to 19 species-level operational taxonomic units (OTUs). Four OTUs were represented in all three libraries, eight OTUs were library-specific, six OTUs were found in only the corn silage and pasture grazing libraries, and one OTU was shared only between pasture grazing and sugar cane libraries. We found that Methanobrevibacter-related sequences were the most abundant in the water buffaloes sampled for our analysis, in contrast to previously reported studies showing that Methanomicrobium mobile-like methanogens were the most abundant methanogens in water buffaloes of Murrah and Surti breeds sampled in India. Considering the worldwide distribution of water buffaloes and the likely wide variety of diets provided, our results combined with studies from other groups support that larger scope analyses of microbiomes for this livestock species would provide great insight into the contribution of geographical location, breed, and diet in determining the population structure of rumen microorganisms.