Blood metabolites and fecal starch as indicators of feed efficiency of beef cattle in the feedlot / [Metabolitos sanguíneos e amido fecal como indicadores da eficiência alimentar do gado de corte em confinamento]

The use of blood metabolites (BM), fecal starch (FS), and apparent digestion of starch, (ATTSD) as indicators of feed efficiency (FE) in beef cattle in the feedlot was studied. Fourteen bulls were used, originating in an industrial cross, without a defined racial group, with mean body weight of 284.86kg, individually fed, being evaluated in a 42-day confinement system. After the evaluation, the animals were divided into two groups according to the individual FE: high feed efficiency (HE) and low feed efficiency (LE). There was a difference between the groups in the variables FE, feed conversion (FC), final weight (FW), and daily weight gain (DWG). The FE had a positive correlation with DWG, FC, and FW. There was no difference between the groups for the variables BM, FS, and ATTSD, nor was there any correlation between these variables and FE. Considering the feed cost, the HE animals proved more profitable. BM, FS, and ATTSD did not statistically show potential to be used as indicators of FE, despite the evidence of numerical differences of these variables between the different groups, tendency of correlations with FE, and discriminating function with potential assertiveness.(AU)

Foi estudada a utilização dos metabólitos sanguíneos (BM), do amido fecal (FS) e da digestão aparente do amido (ATTSD) como indicadores de eficiência alimentar (FE) em bovinos de corte em confinamento. Utilizaram-se 14 touros, originários de cruzamento industrial, sem grupo racial definido, peso corporal médio de 284,86kg, alimentados individualmente, sendo avaliados em sistema de confinamento por 42 dias. Após a avaliação, dividiram-se os animais em dois grupos, de acordo com a FE individual: alta eficiência alimentar (HE) e baixa eficiência alimentar (LE). Houve diferença entre os grupos nas variáveis FE, conversão alimentar (FC), peso final (FW) e ganho de peso diário (DWG). A FE teve correlação positiva com DWG, FC e FW. Não houve diferença entre os grupos para as variáveis BM, FS e ATTSD, tampouco houve correlação entre essas variáveis e a FE. Considerando-se o custo alimentar, os animais HE mostraram-se mais lucrativos. BM, FS e ATTSD não mostraram, estatisticamente, potencial para serem utilizados como indicadores de FE, apesar da evidência de diferenças numéricas dessas variáveis entre os diferentes grupos, tendência de correlações com a FE e de função discriminante com potencial assertividade.(AU)

A combined enrichment/polymerase chain reaction based method for the routine screening of Streptococcus agalactiae in pregnant women

Group B Streptococcus (GBS) is the most common cause of life-threatening infection in neonates. Guidelines from CDC recommend universal screening of pregnant women for rectovaginal GBS colonization. The objective of this study was to compare the performance of a combined enrichment/PCR based method targeting the atr gene in relation to culture using enrichment with selective broth medium (standard method) to identify the presence of GBS in pregnant women. Rectovaginal GBS samples from women at ¡Ý36 weeks of pregnancy were obtained with a swab and analyzed by the two methods. A total of 89 samples were evaluated. The prevalence of positive results for GBS detection was considerable higher when assessed by the combined enrichment/PCR method than with the standard method (35.9% versus 22.5%, respectively). The results demonstrated that the use of selective enrichment broth followed by PCR targeting the atr gene is a highly sensitive, specific and accurate test for GBS screening in pregnant women, allowing the detection of the bacteria even in lightly colonized patients. This PCR methodology may provide a useful diagnostic tool for GBS detection and contributes for a more accurate and effective intrapartum antibiotic and lower newborn mortality and morbidity.

Evaluation of biofilm production by Pseudomonas Aeruginosa isolates recovered from cystic fibrosis and non-cystic fibrosis patients

Cystic fibrosis (CF) patients typically suffer of persistent and recurrent lung infections caused by Pseudomonas aeruginosa that many times possess ability for the biofilm production. Here, biofilm production among P. aeruginosa isolates recovered from sputum of CF and non-CF patients was evaluated. Most isolates were biofilm-producing independently of the patient's condition.

Enterococcus gallinarum carrying the vanA gene cluster: first report in Brazil

In 2000, Enterococcus faecalis resistant to vancomycin was first reported at a tertiary hospital in Porto Alegre, southern Brazil. The resistance spread to other hospitals and surveillance programs were established by hospital infection committees to prevent the spread of vancomycin-resistant enterococci. In February 2002, an isolate initially identified at the genus level as Enterococcus was obtained by surveillance culture (rectal swab) from a patient admitted to a hospital for treatment of septic arthritis in the shoulder. The isolate proved to be resistant to vancomycin by the disc diffusion method and confirmed by an E-test resulting in a minimal inhibitory concentration of > ou = 256 µg/ml. This isolate was sent to a reference laboratory (Laboratório Especial de Bacteriologia e Epidemiologia Molecular, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP) for further study and proved to be an E. gallinarum by the polymerase chain reaction (PCR) using specific primers for the species. Due to the phenotype of unusually high vancomycin resistance, the isolate presumably had the resistance genes (vanA and vanB) and this was confirmed by PCR, which indicated the presence of the vanA gene. A 10.8-kb Tn1546-related transposon was also identified by long-PCR. Interspecies transfer of the vancomycin-resistance gene from the donor E. gallinarum was performed in a successful conjugation experiment in vitro, using E. faecium GE-1 and E. faecalis JH22 as receptors. This is the first report of the detection of a vanA determinant naturally acquired by E. gallinarum in Brazil, indicating the importance of characterizing VRE by both phenotype and genotype methods.

Typing of Pseudomonas aeruginosa from hospitalized patients: a comparison of susceptibility and biochemical profiles with genotype

Typing techniques are essential for understanding hospital epidemiology, permitting the elucidation of the source of infection and routes of bacterial transmission. Although DNA-based techniques are the gold standard for the epidemiological study of Pseudomonas aeruginosa, antibiotic profiles and biochemical results are used because they are easy to perform and to interpret and relatively inexpensive. Antibiotypes (susceptibility profiles) and biotypes (biochemical profiles) were compared to genotypes established by DNA restriction enzyme analysis in 81 clinical isolates of P. aeruginosa from three hospitals in Porto Alegre, Brazil. The epidemiological relationship among patients was also evaluated. Susceptibility and restriction profiles were discrepant in more than 50 percent of the cases, and many antibiotypes were observed among isolates from the same genotype. Furthermore, susceptibility profiles did not allow the distinction of isolates from unrelated genotypes. Since a large number of isolates (63 percent) yielded the same biochemical results, only 10 biotypes were detected, showing that this typing method has a low discriminatory power. On the other hand, DNA restriction enzyme typing allowed us to establish 71 distinct types. Epidemiological data about the relation among P. aeruginosa isolates were not conclusive. The results of the present study indicate that the only method that can establish a clonal relation is DNA restriction enzyme typing, whereas the other methods may cause misleading interpretations and are inadequate to guide proper infection control measures.

Phenotyping and genotyping methods applied to investigate the relatedness of Brazilian isolates of Enterobacter cloacae

In order to evaluate the resolving power of several typing methods to identify relatedness among Brazilian strains of Enterobacter cloacae, we selected twenty isolates from different patients on three wards of a University Hospital (Orthopedics, Nephrology, and Hematology). Traditional phenotyping methods applied to isolates included biotyping, antibiotic sensitivity, phage-typing, and O-serotyping. Plasmid profile analysis, ribotyping, and macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) were used as genotyping methods. Sero- and phage-typing were not useful since the majority of isolates could not be subtyped by these methods. Biotyping, antibiogram and plasmid profile permitted us to classify the samples into different groups depending on the method used, and consequently were not reliable. Ribotyping and PFGE were significantly correlated with the clinical epidemiological analysis. PFGE did not type strains containing nonspecific DNase. Ribotyping was the most discriminative method for typing Brazilian isolates of E. cloacae