COMPARATIVE INVITRO ACTIVITY OF 3 CEPHALOSPORINS AGAINST STAPHYLOCOCCUS-AUREUS ISOLATED FROM BOVINE MASTITIS

This report compares the in vitro activity of three cephalosporins (cephalothin, cefoxitin and ceftriaxone) against 57 Staphylococcus aureus strains isolated from cows with clinical mastitis on the basis of the minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC). The majority of the S aureus strains showed resistance to cefoxitin and ceftriaxone and sensitivity to cephalothin. The highest MICs and MBCs were found for cefoxitin and ceftriaxone. Antimicrobial tolerance (MBC/MIC greater-than-or-equal-to 32:1) was observed in relation to cephalothin and ceftriaxone. The data suggest that these cephalosporins may not be effective for the treatment of staphylococcal bovine mastitis. The precise definition of their antimicrobial efficacies requires more detailed in vitro and in vivo studies.

Antimicrobial effect of intracanal substances

In some situations, endodontic infections do not respond to therapeutic protocol. In these cases, it is suggested the administration of an alternative intracanal medication that presents a wide spectrum of action and has an in-depth effect on the root canal system. The purpose of this study was to assess the antimicrobial action of ciprofloxacin, metronidazole and polyethylene glycol and natrosol vehicles with different associations and concentrations. The minimum inhibitory concentration (MIC) was determined by using the agar dilution method. The culture media (Muller-Hinton agar) were prepared containing antimicrobial agents at multiple two-fold dilutions of 0.25 to 16 mu g/mL, and with the vehicles at the concentrations of 50, 45, 40, 35, 30 and 25%. Twenty-three microbial strains were selected for the study. Metronidazole was not capable of eliminating any of the tested microorganisms. The association of ciprofloxacin with metronidazole resulted in a reduction of the MIC. The vehicle polyethylene glycol inhibited the growth of 100% of the tested strains, while natrosol inhibited 18% of the strains. Ciprofloxacin formulations with polyethylene glycol presented better effects than those of formulations to which metronidazole was added. It was possible to conclude that ciprofloxacin presented antimicrobial action against all tested bacteria] strains, and its association with metronidazole was synergic. The vehicle polyethylene glycol showed antimicrobial effect and the ciprofloxacin/polyethylene glycol association was the most effective combination for reducing the tested bacteria and yeasts.

Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria ( Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides) from alcoholic fermentation, through the method of minimum inhibitory concentration ( MIC), as well as its effect on the industrial yeast inoculum. Lower MIC was found for B. subtilis ( 10 ppm) and Leuconostoc mesenteroides ( 50 ppm) than for Lactobacillus fermentum ( 75 ppm) and Lactobacillus plantarum ( 125 ppm). Additionally, these concentrations of chlorine dioxide had similar effects on bacteria as 3 ppm of Kamoran (R) ( recommended dosage for fermentation tanks), exception for B. subtilis, which could not be controlled at this Kamoran (R) dosage. The growth of industrial yeasts was affected when the concentration of chlorine dioxide was higher than 50 ppm, but the effect was slightly dependent on the type of yeast strain. Smooth yeast colonies ( dispersed cells) seemed to be more sensitive than wrinkled yeast colonies ( clustered cells/pseudohyphal growth), both isolated from an alcohol-producing unit during the 2006/2007 sugar cane harvest. The main advantage in the usage of chlorine dioxide that it can replace antibiotics, avoiding the selection of resistant populations of microorganisms.

Chronic Suppurative Otitis Media in Cleft Palate: Microorganism Etiology and Susceptibilities

Objective: To investigate the microbial etiology of suppurative chronic otitis media (SCOM) in patients with complete cleft lip and palate and isolated cleft palate and to determine the sensitivity of isolated microorganisms to antibiotics by drug diffusion from impregnated discs in agar and the minimum inhibitory concentration of each drug to these microorganisms by drug dilution in agar.Design/Patients: Effusion samples of SCOM obtained from 40 patients with cleft lip and palate registered at the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, at Bauru, Brazil, were bacteriologically analyzed by cultures. The isolated bacteria were submitted to an in vitro susceptibility test to clinically used drugs.Results: Positive cultures were obtained in 100% of studied cases. Among the 57 strains observed, the most frequent were Pseudomonas aeruginosa (35%), Staphylococcus aureus (15.5%), Enterococcus faecalis (14%), and Proteus mirabilis (12%). The frequency of Gram-negative bacilli (enterobacteriaceae and nonfermentative bacilli) was 67%. Pseudomonas aeruginosa presented the highest sensitivity to ciprofloxacin, and enterobacteriaceae exhibited the highest sensitivity to gentamicin. The strains of S. aureus and E. faecalis presented the highest sensitivity to imipenem and sulfamethoxazole/trimethoprim, respectively.Conclusion: Patients with cleft lip and palate presenting with SCOM exhibited 100% positive cultures, with the highest frequency of Pseudomonas and enterobacteriaceae. With regard to the action of antibiotics, imipenem was effective against the four species of isolated microorganisms, followed by ciprofloxacin, which was effective against 75% of isolated species.

Atividade antimicrobiana de extratos brutos de Petiveria alliacea L.

"Antimicrobial activity of crude extratcs of Petiveria alliacea L.". Petiveria alliacea L. (Phytolaccacea) is an herbaceous plant of great importance in traditional medicine. This species have been widely used in several applications such as antirheumatic, anticarcinogenic, anti-flu, antitussive, analgesic, insecticidal, acaricidal, as well as bactericide and fungicide. Currently, the pathogenic microorganisms are acquiring resistence against the traditional antibiotics, and the search for new herbal antimicrobial agents has been intensified. The objective of this study was to evaluate the antifungal and antibacterial activity of several leaf crude extracts of P. alliacea against several strains of bacterias and yeasts namely Bacilus subtilis, Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Candida parapsilosis, Candida kefyr and Candida albicans, using microdilution method. Promising results were observed for the 70% v/v ethanolic extract which presented minimum inhibitory concentration (MIC) from 250 to 760 mu g/mL for yeast. For the bacteria strains tested the MIC ranged between 240 to 3960 mu g/mL, depending of the extractive solution tested.

The in vitro antiviral activity of an aliphatic nitro compound from Heteropteris aphrodisiaca

We investigated the antiviral activity of an aliphatic nitro compound (NC) isolated from Heteropteris aphrodisiaca O. Mach. (Malpighiaceae), a Brazilian medicinal ptant. The NC was tested for its antiviral activity against poliovirus type 1 (PV-1) and bovine herpes virus type 1 (BHV-1) by plaque reduction assay in cell culture. The NC showed a moderate antiviral activity against PV-1 and BHV-1 in HEp-2 celts, and the 50% inhibitory concentration (IC50) were 22.01 mu g/ml (selectivity index (SI) = 2.83) and 21.10 mu g/mi (SI = 2.95), respectivety. At the highest concentration of the drug (40 mu g/ml) a reduction of approximately 80% in plaque assay was observed for both viruses. The treatment of cells or virus prior to infection did not inhibit the replication of virus strains. (C) 2006 Elsevier GmbH. All rights reserved.

Avaliacao da atividade da nova cefalosporina de quarta geracao cefpiroma contra amostras clinicas isoladas em unidades de terapia intensiva e unidades de oncoematologia de varios hospitais brasileiros

Objective: To evaluate the in vitro activity of the fourth-generation cephalosporin cefpirome in comparison to that of ceftazidime, ceftriaxone, cefotaxime and imipenem in a multicenter study involving nine hospitals from six cities (four states). Material and methods: A total of 804 isolates from patients hospitalized in either intensive care units or Oncology/Hematology units was evaluated. The isolates were collected between June and November of 1995, i.e. before cefpirome became commercially available in Brazil, and susceptibility tested by broth microdilution following the NCCLS procedures. All isolates resistant to cefpirome were retested by B-test. Results: Against Enterobacteriaceae (n = 344), cefpirome demonstrated an activity 2 to 32-fold higher than that of the third-generation cephalosporins (TGCs) and similar to that of imipenem. The percentages of Enterobacteriaceae susceptible were: 88%, 69% and 96% for cefpirome, TGCs and imipenem, respectively, The cefpirome spectrum were greater or equal to that of imipenem against Citrobacter freundii, Enterobacter aerogenes, Morganellao morganii and Serratia marcescens. Against Acinetobacter sp. (n = 77), cefpirome was slightly more active than ceftazidime; however, the percentages of isolates resistant to these compounds were high (84% and 88%, respectively). The activities of cefpirome, ceftazidime and imipenem were very similar against P. aeruginosa isolates (n = 128), with MIC50 (μg/ml) percent susceptible of 8/59%, 8/62% and 4/62% respectively, Against aerobic gram-positive bacteria, the cefpirome activity was 4 to 16-fold higher than that of TGCs but 2 to 8-fold lower than that of imipenem. Conclusion: The results of our study suggest that, in Brazil, cefpirome has a spectrum of activity which is higher than that of the TGCs against aerobic gram-negative (Enterobacteriaceae and non-Enterobacteriaceae) and gram-positive bacteria and similar to that of imipenem against some Enterobacteriaceae species and P. aeruginosa.