Biomedical subjects

F Bernardo

Publications and source records attributed to F Bernardo.

At least 19 recordsLinked to original sources

PubMed2006

Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates.

Biofilm-forming ability has been increasingly recognized as an important virulence factor in Staphylococci, facilitating their persistence in the host, evading its defences and allowing bacterial survival at high antimicrobial concentrations. Staphylococcus aureus remains a major pathogen of chronic mastitis, but in the last years Staphylococcus epidermidis has emerged as a relevant mastitis pathogen. The present work aimed at the evaluation of the biofilm-forming ability of Staphylococci field isolates from bovine subclinical mastitis and at the development of a fluorescent in situ hybridisation (FISH) protocol that would allow the direct observation of biofilm formation in milk samples. The analysis of phenotypic expression in Congo Red Agar (CRA) and by FISH, showed that 37.5% of the S. aureus isolates produced biofilm, while by optical density measurement only 18.75% isolates revealed this phenotype. The results showed a fair agreement according to the kappa coefficient test (kappa = 0.259). Regarding S. epidermidis mastitis isolates, 37.5% revealed the ability to produce biofilm, but only four isolates were positive by all methods. This agreement was moderate (kappa = 0.467). The application of FISH to artificially contaminated milk samples allowed the direct observation of biofilm production by 37.5% isolates, showing total agreement with the CRA results. This method better mimics the in vivo conditions, especially in terms of the presence of calcium and iron, which in high concentrations, respectively, are known to inhibit or induce biofilm production.

Animals↗

PubMed2002

Influence of puerperal uterine infection on uterine involution and postpartum ovarian activity in dairy cows.

This article presents the results of a clinical trial designed to study the effect of puerperal uterine infection on uterine involution and on ovarian activity in dairy cows, monitored twice weekly from parturition until the sixth week postpartum (wpp). Infection significantly retarded uterine involution assessed by the uterine body diameter and a score of intrauterine fluid volume (IUFV). By the sixth wpp, cows with normal puerperium (controls) and cows that showed mild puerperal endometritis had similar uterine body diameter and IUFV, indicating spontaneous recovery within the postpartum voluntary waiting period. However, in cows with severe puerperal endometritis, although uterine body diameter had regressed to pregravid size, IUFV remained significantly higher than in control and mild endometritis cows, indicating that chronic endometritis was established. The IUFV score was positively and significantly correlated with uterine swab bacterial growth density and allowed diagnosis of endometritis after the third wpp. Cows with mild or severe endometritis had a significantly higher prevalence and persistence of pathogenic bacteria (Escherichia coli, Actinomyces pyogenes, Gram-negative anaerobes - GNA) than controls. Actinomyces pyogenes was associated to GNA in 74% of isolations. Ovarian activity measured by ultrasound scanning of the ovaries and plasma progesterone (P4) concentrations was more abnormal (prolonged anoestrus, prolonged luteal phases and ovarian cysts) in cows with severe endometritis than in controls.

Animals↗

PubMed2002

Amplified fragment length polymorphism (AFLP) analysis of Listeria monocytogenes.

An agarose gel based single enzyme AFLP method using EcoR1 digestion of Listeria monocytogenes DNA was developed for epidemiological typing. The method was evaluated with 84 L. monocytogenes cultures, and results were compared with those obtained with serotyping, phage-typing and cadmium and arsenic resistance typing. The AFLP method was reproducible and 14 different banding patterns comprising between five and eight DNA fragments were produced. All except two of the AFLP patterns were serorype specific. Different AFLP patterns were recognised within serovar 4b (four patterns), 1/2a (two patterns), 1/2b (six patterns): single patterns were obtained from cultures of serovars 1/2c, 3a, 3b and 3c. There were associations with AFLP results and those from phage-typing and cadmium and arsenic resistance typing, although each method showed some independence. This preliminary evaluation suggests that this AFLP method will be useful for epidemiological typing of L. monocytogenes.

Animals↗

PubMed2002

Co-occurrence of patulin and citrinin in Portuguese apples with rotten spots.

Patulin and citrinin are mycotoxins produced by certain fungi mainly belonging to Penicillium and Aspergillus and may be detected in mouldy fruits and fruit products. The data presented here refer to the simultaneous occurrence of patulin and citrinin in 351 samples of seven different varieties of apples with small rotten areas (Casanova, Golden Delicious, Red Delicious, Reineta, Richared, Rome Beauty, Starking). A rapid multidetection thin layer chromatography (TLC) method was used. The minimum detectable concentrations of patulin and citrinin were 120-130 and 15-20 microg kg(-1) respectively. The percentage contamination with patulin only was higher (68.6%) than that with citrinin only (3.9%). Patulin and citrinin (19.6%) were also detected simultaneously. The highest mean patulin content was 80.50 mg kg(-1) for the Richared variety, but the mean level of citrinin was lower. The lowest mean contaminations of patulin were found in Rome Beauty, Red Delicious and Reineta, ranging from 3.06 to 5.37 mg kg(-1). All analysed apples varieties had low citrinin contamination, ranging from 0.32 to 0.92 mg kg(-1). These findings indicate that there may be a risk of human exposure to patulin through the consumption of juices and jams manufactured with apples with small rotten areas.

Chromatography, Thin Layer↗

PubMed2001

Evaluation of microbiological quality of medicinal plants used in natural infusions.

Consumption of preparations of medicinal plants has been increasing during the last decades in occidental societies. However, there are no effective sanitary controls of these products. To evaluate the nature and content of microbiological contamination, 62 samples of seven medicinal plants (chamomile, leaves of orange tree, flowers of linden, corn silk, marine alga, pennyroyal mint and garden sage) were studied, using conventional microbiological methods. Practically all samples (96.8%) were contaminated with Bacillus cereus; 19.2% of them with levels higher than 10(3) spores/g. The highest levels were found in corn silk samples (> 10(7) spores/g). Spores of Clostridium perfringens were detected in 83.9% of samples, but only 19.2% had levels greater than 10(3)/g. The mean level of fungal population was 10(5.5) cfu/g. Corn silk samples were the most contaminated, with levels above 10(6) cfu/g. Fusarium spp., Penicillium spp., Aspergillus flavus and Asp. niger were predominant in all samples with the exception of garden sage samples. Many yeasts were found in chamomile, flowers of linden, corn silk, pennyroyal mint and garden sage. Predominant species were Cryptococcus laurentii (28.1%) and Rhodotorula mucilaginosa (22.8%). The mean level of Crypt. laurentii contamination in corn silk was greater than 10(4) cfu/g.

Bacillus cereus↗

PubMed2001

Aflatoxins in spices marketed in Portugal.

Seventy-nine prepackaged samples of 12 different types of spice powders (five cardamom, five cayenne pepper, eight chilli, five cloves, seven cumin, five curry) powder, five ginger, five mustard, 10 nutmeg, 12 paprika, five saffron and seven white pepper) were selected from supermarkets and ethnic shops in Lisbon (Portugal) for estimation of aflatoxins by immunoaffinity column clean-up followed by HPLC. Aflatoxin B1 (AFB1) was detected in 34 samples of prepackaged spices (43.0%). All of the cayenne pepper samples were contaminated with levels ranging from 2 to 32 microg AFB1/kg. Three nutmeg samples contained levels ranging from 1 to 5 microg/kg, three samples had levels ranging from 6 to 20 microg/kg, and there were two with 54 microg/kg and 58 microg/ kg. Paprika contained levels of aflatoxin B1 ranging from 1 to 20 microg/kg. Chilli, cumin, curry powder, saffron and white pepper samples had levels ranging from 1 to 5 microg/kg. Aflotoxins were not detected in cardamon, cloves, ginger and mustard. None of the samples analysed contained aflatoxins B2, G1 and G2.

Aflatoxins↗

PubMed2001

Fumonisins B1 and B2 in black tea and medicinal plants.

Fumonisins are mycotoxins produced by Fusarium moniliforme that are prevalent in cereals and other agricultural products. These mycotoxins have been pointed to as a natural cause of equine leukoencephalomalacia, porcine pulmonary edema, and human esophageal cancer. A total of 87 samples, 18 black tea samples and 69 samples of four different medicinal plants (chamomile, leaves of the orange tree, leaves and flowers of the linden tree, and corn silk), for infusions preparations were acquired from supermarkets in Lisbon, Portugal. The samples were analyzed for the incidence and levels of fumonisin B1 (FB1) and fumonisin B2 (FB2) by high-performance liquid chromatography. The detection limit was 20 microg/kg for both FB1 and FB2. FB1 was detected in 55 (65.5%) of the 87 samples. The highest number of positive samples was found in black tea (88.8%). with levels ranging from 80 to 280 microg/kg. Relative to the medicinal plants, the leaves of the orange tree had higher concentrations of FB1 (range, 350 to 700 microg/kg) followed by leaves and flowers of the linden tree (range, 20 to 200 microg/kg). The samples of corn silk and chamomile had less contamination of FB1, with concentrations ranging from 50 to 150 microg/kg and 20 to 70 microg/kg, respectively. None of the samples tested had contamination of FB2. This is the first report of the natural occurrence of fumonisins in black tea and medicinal plants in Portugal. We reinforce the necessity to implement risk management measures for safety control of this kind of product.

Carboxylic Acids↗

PubMed1995

Influence of non-steroidal anti-inflammatory drugs on renal function and 24h ambulatory blood pressure-reducing effects of enalapril and nifedipine gastrointestinal therapeutic system in hypertensive patients.

OBJECTIVE: To evaluate the influence of non-steroidal anti-inflammatory drugs (NSAIDs; aspirin and indomethacin) on the renal and antihypertensive effects of enalapril and nifedipine gastrointestinal therapeutic system (GITS) in patients with essential hypertension. DESIGN AND METHODS: In a crossover study, 18 patients on an unrestricted-salt diet were randomly assigned to receive either enalapril (20-40 mg/day) or nifedipine-GITS (30-60 mg/day) for 4-8 weeks, followed by aspirin (100 mg/day for 2 weeks) and then indomethacin (75 mg/day for 1 week). Blood pressure was measured by 24h ambulatory monitoring. RESULTS: Enalapril and nifedipine-GITS significantly reduced blood pressure compared with placebo. Aspirin did not alter the antihypertensive effect of either drug. Indomethacin attenuated (by 45%) the antihypertensive effect of enalapril throughout the 24h period of evaluation, but did not interfere with the effect of nifedipine. Furthermore, indomethacin significantly reduced the fractional excretion of sodium and plasma levels of prostaglandins in a similar way when added to either the enalapril or the nifedipine regimen. CONCLUSIONS: Vasodilatory prostaglandins are probably involved in the antihypertensive effects of enalapril but not of nifedipine, and this interaction seems to be independent of any indomethacin-induced decrease in renal sodium excretion. Nifedipine may be an appropriate drug to treat hypertensive patients requiring concomitant therapy with NSAID.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1990

Prevalence of Salmonella in chicken carcasses in Portugal.

During 1986-87 57% of 300 chicken carcasses yielded salmonellas where tested by a swabbing method. Serotypes isolated were Salmonella enteritidis (66%), Salm. agona (12%), Salm. newport (6%), Salm. saintpaul (6%), Salm. derby (4%), Salm. typhimurium (3%), Salm. bardo (1%), Salm. ohio (1%) and untypable (2%). The results are compared with those of avian and human salmonellosis registered in Portugal during the same period.

Abattoirs↗

PubMedDate not supplied