RESUMEN

The present study investigated the antimicrobial and antibiofilm potential of biosurfactants derived from Lactobacillus fermentum Lf1, L. fermentum LbS4 and Lactobacillus plantarum A5 against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). The cell wall-bound and intracellular biosurfactants were extracted by solvent extraction method. Fourier-transform infrared spectroscopy-based characterization of biosurfactants revealed the heterogeneous chemical composition involving proteins, fatty acids and carbohydrate moieties in LbS4 and A5, while only the sugar and lipid fractions in Lf1. Fatty acid profiling using Gas chromatography-mass spectrometry indicated hexadecanoic acid and stearic acid as the predominant fatty acids in the biosurfactants of all these strains. Biosurfactants demonstrated dose-dependent antibacterial action against MRSA isolates with the highest inhibition zone diameter (30·0 ± 0·0 to 35·0 ± 0·0 mm) recorded at 400 mg ml-1 . Biosurfactants showed an excellent staphylococcal antibiofilm activity by preventing the biofilm formation and disrupting the preformed biofilms. Visual inspection through scanning electron microscopy witnessed the biosurfactants-induced alteration in the cell membrane integrity and subsequent membrane pore formation on staphylococcal cells. Taken together, our findings emphasize the prospects of biomedical applications of biosurfactants as bactericidal and biofilm controlling agents to confront staphylococcal nosocomial infections.

Asunto(s)

RESUMEN

CONTEXT: Body mass index (BMI), serum albumin, and C-reactive protein (CRP) appear to be major determinants of hospitalization. AIM: To determine the predictive ability of BMI, Sequential Organ Failure Assessment (SOFA score), serum albumin, and CRP to assess the duration and outcome of mechanical ventilation (MV). MATERIALS AND METHODS: Thirty patients aged >18 years who required mechanical ventilation (MV) were enrolled for the study. They were divided into two groups; patients who improved (Group 1), patients who expired (Group 2). Group 1 was further divided into two groups: patients on MV for <5 days (Group A), and patients on MV for >5days (Group B). BMI and SOFA score were calculated, and serum albumin and CRP were estimated. RESULTS AND DISCUSSION: Out of the 30 patients, 18 patients successfully improved after MV (Group 1) and 12 patients expired (Group 2). Among the 18 patients in group 1, ten patients improved within 5 days (Group A) and 8 patients after 5 days (Group B). SOFA score and CRP were significantly increased (P value 0.0003 and 0.0001, respectively) in group 2 when compared to group 1. CRP >24.2 mg/L or SOFA score >7 at the start of MV increases the probability of mortality by factor 13.08 or 3.92, respectively The above parameters did not show any statistical difference when group A was compared to group B. CONCLUSION: Simple, economic and easily accessible markers like CRP and assessment tools of critically ill patients with SOFA score are important determinants of possible outcomes of a patient from MV.

RESUMEN

A high performance liquid chromatographic method for the determination of PAT-5A (a potent insulin sensitizer) using DRF-2095 (a thiazolidinedione) as internal standard (I.S.) is described. A 1:1 v/v ethylacetate and dichloromethane solvent mixture was used for extraction of PAT-5A from plasma. A Kromasil KR100-5C18-250A, 5 microm, 4.6 x 250 mm SS column was used for the analysis. Mobile phase consisting of sodium dihydrogen phosphate (pH 4.0, 0.05 M) and methanol mixture (25:75, v/v) was used at a flow rate of 1.0 ml/min. The eluate was monitored using a UV detector set at 345 nm. Ratio of peak area of analyte to I.S. was used for quantification of plasma samples. Using this method the absolute recovery of PAT-5A from rat plasma was > 90% and the limit of quantification was 0.05 microg/ml. The intra-day relative standard deviation (RSD) ranged from 2.19 to 4.98% at 1.0 microg/ml, 1.05 to 3.68% at 10.0 microg/ml and 3.14 to 5.08% at 50 microg/ml. The inter-day RSD were 1.6, 2.24 and 1.54% at 1, 10 and 50 microg/ml, respectively. The method was applied to measure the plasma concentrations of PAT-5A in pharmacokinetic and bioavailability studies in male Wistar rats.

Asunto(s)

RESUMEN

Following an identified use of the plant as analgesic in traditional medicine, the hexane, chloroform and ethyl acetate extracts of Euphorbia heterophylla root have been tested for antinociceptive activity in rats. All extracts showed significant effects at doses of 150-300 mg/kg i.p.

Asunto(s)

RESUMEN

OBJECTIVE: The aim of this randomised, double-blind, crossover study was to evaluate the effect of single-dose probenecid on the pharmacokinetics of ofloxacin in eight healthy male volunteers. METHODS: After an overnight fast, and according to a randomised sequence, each volunteer received either single oral ofloxacin 200mg (Hoechst Marion Roussel Ltd., Mumbai, India) or both ofloxacin (1 x 200mg) and probenecid (1 x 500mg) [Geno Pharmaceutical Ltd., Mumbai, India]. Blood samples were collected at regular intervals until 24 hours. Serum concentration versus time profiles for ofloxacin were generated and pharmacokinetic parameters were calculated by noncompartmental model analysis. RESULTS: Elimination half-life, mean residence time and area under the curve were significantly increased (4.86 vs 5.26h; 7.23 vs 7.95h; 10.28 vs 11.9 mg/L . h) [p < 0.01], whereas the total clearance was decreased (19.66 vs 16.95 L/h) [p < 0.01] in the presence of probenecid. Other pharmacokinetic parameters were not significantly affected by coadministration of probenecid. CONCLUSION: Concomitant administration of probenecid with ofloxacin may result in a decreased elimination half-life and consequently increased bioavailability of ofloxacin. Probenecid may be co-prescribed with ofloxacin; patients taking this combination should be closely monitored and dosage reduction should be considered if warranted in high-risk patients.

RESUMEN

The survival of several strains of Staphylococcus aureus after heat stress in different menstrua was not logarithmic and F-values were determined to express their resistance to heat. Of the strains tested, Staph. aureus 234 (enterotoxin B) was the most heat resistant and Staph. aureus 790 (enterotoxin E) was the most heat sensitive. Buffalo milk gave the best protection to all the strains of Staph. aureus against heat, followed by cow's milk; phosphate-buffered saline gave the least protection. Soyabean casein digest agar gave maximum recovery of survivors followed by brain heart infusion and Baird-Parker medium. At 50 degrees C there was no marked variation in coagulase production by the surviving strains but at 55 and 62.5 degrees C there was complete loss of coagulase activity. There was a decreased deoxyribonuclease (DNase) production by all the strains of Staph. aureus after heat stress. Heat-treatment at 55 and 62.5 degrees C resulted in loss of enterotoxin production by all the survivors except S6 and 234, the surviving cells of which still produced enterotoxin B after heat treatment at 55 degrees C. Most of the survivors regained lost characteristics such as coagulase, DNase and enterotoxin production after four to five passages through BHI which suggests that subculture of Staph. aureus recovered from heat-processed milk is necessary to avoid false results.

Asunto(s)