Antimicrobial Vancomycin Research Articles

Bacteriological characteristics of primary breast abscesses in patients from the community in the era of microbial resistance.

The aim of this study is to evaluate the etiological profile and antimicrobial resistance in breast abscess cultures from patients from the community, treated at a public hospital located in Porto Alegre, Brazil. This is an retrospective cross-sectional study that evaluated the medical records of patients with bacterial isolates in breast abscess secretion cultures and their antibiograms, from January 2010 to August 2022. Based on 129 positive cultures from women from the community diagnosed with breast abscesses and treated at Fêmina Hospital, 99 (76.7%) of the patients had positive cultures for Staphylococcus sp, 91 (92%) of which were cases of Staphylococcus aureus. Regarding the resistance profile of S. aureus, 32% of the strains were resistant to clindamycin, 26% to oxacillin and 5% to trimethoprim-sulfamethoxazole. The antimicrobials vancomycin, linezolid and tigecycline did not show resistance for S. aureus. Staphylococcus aureus was the most common pathogen found in the breast abscess isolates during the study period. Oxacillin remains a good option for hospitalized patients. The use of sulfamethoxazole plus trimethoprim should be considered as a good option for use at home, due to its low bacterial resistance, effectiveness and low cost.

Rapid and dynamic detection of antimicrobial treatment response using spectral amplitude modulation in MZO nanostructure-modified quartz crystal microbalance

We report a dynamic and rapid detection of the response of S. epidermidis to various antimicrobial treatments utilizing the real-time spectral amplitude modulations of the magnesium zinc oxide nanostructure-modified quartz crystal microbalance (MZOnano-QCM) biosensor. The sensor consists of a quartz crystal microbalance (QCM) with magnesium zinc oxide (MZO) nanostructures grown directly on the sensing electrode using metalorganic chemical vapor deposition (MOCVD). Combining the high sensitivity detection of bacteria provided by the MZO nanostructures with the QCM's dynamic acoustic spectrum makes a highly-sensitive dynamic biosensor well-suited for monitoring viscoelastic transitions during drug treatment compared to the QCM's conventional frequency shift signals. We demonstrated dynamically monitoring the response of S. epidermidis to various concentrations of the drug ciprofloxacin, and response to three different antimicrobials vancomycin, oxacillin, and ciprofloxacin, using spectral amplitude modulations of the MZOnano-QCM. Our results indicate that the amplitude modulations exhibit high sensitivity to S. epidermidis response to different drug treatments compared to the conventional frequency shift signals of the device, allowing for rapid determination (within 1.5 h) of the efficacy of the antimicrobial drug. The high sensitivity demonstrated by the spectral amplitude modulations is attributed to the direct relationship of these signals to the viscoelastic transitions of the bacterial cells on the device's sensing area while responding to drug treatment. This relationship is established by the Butterworth-Van-Dyke (BVD) model of the MZOnano-QCM. Standard microbiological protocols and assays were performed to determine the optimal drug dosages and the minimum inhibitory concentrations to serve as the benchmark for the sensor data.

Atividade antimicrobiana do óleo essencial de Cymbopogon citratus (D. C.) Stapf. (Capim-Santo) sobre Staphylococcus aureus e. Escherichia coli

This work aimed to evaluate the antimicrobial potential of essential oil (EO) from leaves of Cymbopogon citratus (D. C.) Stapf. on Staphylococcus aureus and Escherichia coli and to verify the possible synergism and/or antagonism of the EO when combined with the antimicrobials vancomycin and chloramphenicol. The extraction of the EO was performed with the Clevenger extractor system. For the tests, strains of S. aureus and E. coli were used, which were activated and maintained in the Microbiology Laboratory of UNEB, Campus X. The testes were performed using Petri dishes containing Muller-Hinton Agar and applying the disc-diffusion methodology. Analyses were performed using three dishes containing the EO extracted by the Clevenger. In each dish, suspensions of S. aureus were plated and six discs were deposited: a white disc with saline solution (negative control); one disc of the antimicrobial vancomycin (positive control), and four discs with different concentrations (1.0, 0.5, 0.25 and 0.125) of the diluted EO in Tween 80. The same procedure was applied for the test against E. coli, using the chloramphenicol antimicrobial. Results show that there was antimicrobial activity of the EO against S. aureus and E. coli. The analysis of the combination of EO with antimicrobials suggests that there was no synergistic or antagonistic action, both with vancomycin and chloramphenicol. In conclusion, the results of this work show that the EO of Cymbopogon citratus (D. C.) Stapf. presents antimicrobial activity against S. aureus and E. coli.