Suchergebnisse

Bacterial count (SPC) and somatic cell count (SCC) are considered universal indicators of milk quality. The objective of this study was to identify SPC and SCC clusters in milk samples from three microregions of the state of Rondônia and to evaluate the influence of year period and tank type on these indicators. A total of 566 milk cooling tanks linked to dairy industries with the Federal Inspection Service located in the Ariquemes, Ji-Paraná and Porto Velho microregions were evaluated. The SPC and SCC results of the tank samples and the geographical coordinates were obtained from the dairy industry database; the study focused on the results of official analyses carried out by the Laboratories of Milk Quality accredited to the Ministry of Agriculture, Livestock and Food Supply (MAPA) in 2015, constituting a pool of 6,792 data subsets from 2,209 farmers. To elaborate the spatial distribution maps of the quality indicators, the ArcView 3.1® software was used. Spatial dependence was evaluated by geostatistics, using the ordinary kriging method for data interpolation. Variance analysis (ANOVA) was performed using the SAS 9.0 GLM procedure on the logarithmic transformation of SCC and SPC, using as variables the type of tank (individual and collective) and season (dry and rainy). The frequency of milk quality adjustments to the limits defined in the legislation has shown that SPC is a major challenge for the state's production chain. There were no significant differences in this frequency for SCC and SPC, neither between the microregions studied, nor between the dry and rainy season (p > 0.05). The analysis of variance considered the period of year and type of cooling tank and showed higher SPC and SCC in the rainy season (p < 0.05); SCC and SPC were higher in collective tanks used by more than 5 farmers (p < 0.05). Spatial dependence was weak for SCC (DD = 22.02) and moderate for SPC (DD = 25.93), indicating the Machadinho do Oeste region as a priority area for mastitis control, and the Ariquemes microregion and west of the Porto Velho microregion as areas of high SPC. The results demonstrated the feasibility of spatial analysis as a tool for evaluating of refrigerated raw milk quality indicators and may support the definition of public and private strategies and policies to improve the milk quality and legislation adequacy.

Bacterial count (SPC) and somatic cell count (SCC) are considered universal indicators of milk quality. The objective of this study was to identify SPC and SCC clusters in milk samples from three microregions of the state of Rondônia and to evaluate the influence of year period and tank type on these indicators. A total of 566 milk cooling tanks linked to dairy industries with the Federal Inspection Service located in the Ariquemes, Ji-Paraná and Porto Velho microregions were evaluated. The SPC and SCC results of the tank samples and the geographical coordinates were obtained from the dairy industry database; the study focused on the results of official analyses carried out by the Laboratories of Milk Quality accredited to the Ministry of Agriculture, Livestock and Food Supply (MAPA) in 2015, constituting a pool of 6,792 data subsets from 2,209 farmers. To elaborate the spatial distribution maps of the quality indicators, the ArcView 3.1® software was used. Spatial dependence was evaluated by geostatistics, using the ordinary kriging method for data interpolation. Variance analysis (ANOVA) was performed using the SAS 9.0 GLM procedure on the logarithmic transformation of SCC and SPC, using as variables the type of tank (individual and collective) and season (dry and rainy). The frequency of milk quality adjustments to the limits defined in the legislation has shown that SPC is a major challenge for the state's production chain. There were no significant differences in this frequency for SCC and SPC, neither between the microregions studied, nor between the dry and rainy season (p > 0.05). The analysis of variance considered the period of year and type of cooling tank and showed higher SPC and SCC in the rainy season (p 0,05). A análise de variância considerou o período do ano e tipo de tanque de resfriamento e demonstraram maiores CPP e CCS no período chuvoso (p<0,05). Considerando os tipos de tanque, a CCS e CPP foram mais elevadas nos tanques coletivos com mais de 5 produtores (p<0,05). Houve dependência espacial fraca para CCS (GD=22,02) e moderada para CPP (GD=25,93), indicando a região de Machadinho do Oeste como área prioritária para o controle da mastite, e a microrregião de Ariquemes e à oeste da microrregião de Porto Velho como áreas de alta CPP. Os resultados poderão subsidiar a definição de estratégias e de políticas públicas e privadas para melhoria da qualidade do leite do estado.

Staphylococcus aureus is the main etiological agent of bovine mastitis worldwide and knowledge about its diversity and virulence factors is vital in controlling infections caused by this pathogen. The present study aimed to perform molecular characterization of a population of S. aureus (n=153 strains isolated from 1994 to 2014 in seven Brazilian states) by pulsed-field gel electrophoresis (PFGE) and evaluate their virulence profiles via polymerase chain reaction (PCR). PFGE identified 93 pulsotypes, with the isolates organized into 26 clusters and 20 unique pulsotypes. Predominant pulsotypes were observed, with variations according to the years of isolation and geographic origin of the isolates. Based on the PCR results for the genes encoding agglutination factors (ClfA and ClfB), binding proteins (fibronectin binding protein - FnBPA, elastin binding protein - Ebps, collagen binding protein - Cna), and toxins (Hla, Hlb and Luk-ED), 40 virulence profiles were detected. The frequency of virulence genes ranged from 58 to 98% (clfA:84.3%; clfB and hlb both 81%; hla:71.2%; fnBA:82.3%; Can:94.7%; ebps:58%; and lukED:98%). The existence of prevalent genotypes in some of the Brazilian states and the time period studied suggests that these genotypes are better adapted, with favorable characteristics in host/pathogen relationships. Genes of proven importance for S. aureus pathogenesis in bovine mastitis were widely distributed in genetically divergent populations, suggesting that most of these genes may be interesting candidates in the development of vaccines to control bovine mastitis in Brazil.

Staphylococcus is one of the most frequent etiological agents of bovine mastitis, causing economic losses to milk farming. This study aimed to describe the milk production and management practices in 15 herds located in three microregions of the State of Rondônia and to identify the antimicrobial resistance profile of 97 isolates of the genus Staphylococcus from these herds. The isolates were subjected to antimicrobial susceptibility tests using the agar diffusion method. Twenty-nine S. aureus isolates were selected to determine their minimum inhibitory concentration (MIC). In the farms studied, the breeding system was semi-intensive, with the Girolando breed being predominant. Milking was performed predominantly using a mechanical milking system (86.7%), twice a day (66.7%), in the presence of the calf (53.8%). The average number of lactating cows in the farms was 24, with an average milk production of 204.9 L d-1 and a milk productivity of 10.2 L animal-1 d-1. The use of antimicrobials for the treatment and prevention of bovine mastitis was reported for all properties, and therapy for dry cows was adopted in 80% of the herds. The percent susceptibility to antimicrobials ranged from 85.5% to 100% for S. aureus, 22.2% to 88.9% for coagulase-positive staphylococci (CPS), and 69.2% to 100% for coagulase-negative staphylococci (CNS), with the highest resistance frequencies for penicillin, ampicillin, and tetracycline. Among the S. aureus isolates, 100% susceptibility to oxacillin, cefalexin, and gentamicin was observed, and among the CNS isolates, 100% susceptibility to gentamicin was observed. None of the antimicrobials tested showed 100% in vitro effectiveness for CPS. CPS and CNS presented lower percentages of susceptibility to penicillin, ampicillin, and tetracycline than the S. aureus isolates. Twelve resistance patterns were detected, six of which were multiresistance patterns. The most prevalent resistance patterns were penicillin and ampicillin (PEN-AMP) and penicillin, ampicillin, and tetracycline (PEN-AMP-TET). Results of the MIC assay revealed that all 29 S. aureus isolates were susceptible to cephalothin, cefoxitin, tetracycline, and erythromycin, whereas 25 (86.2%) were susceptible to penicillin.