Antifungal Effect of Carrot Carotenoids on Candida Species

BACKGROUND

Candidiasis is a serious problem in women's health that is caused by Candida species, especially Candida albicans. In this study, the effect of carotenoids in carrot extracts on Candida species including Candida albicans ATCC1677, Candida glabrata CBS2175, Candida parapsilosis ATCC2195, and Candida tropicalis CBS94 was investigated.

METHODS

In this descriptive study, the carrot plant was prepared from a carrot planting site in December 2012, and then the characteristics of the plant were determined. After extracting carotenoids from carrots, the susceptibility of different Candida species to carotenoids in carrot extract was determined. Also, the minimum inhibitory concentration and the minimum lethal concentration of the extracts were measured by the macro-dilution method. Finally, the data were analyzed by SPSS software using the Kruskal-Wallis test and Mann-Whitney post-hoc test with Bonferroni adjustment.

RESULTS

The highest growth inhibition zone was obtained for carrot extract at a concentration of 500 mg/ml for C. glabrata and C. tropicalis. The MFC of carrot extract on Candida species was 62.5 mg/ml for C. albicans, C. glabrata, and C. parapsilosis, and 125 mg/ml for C. tropicalis. The MFC of carrot extract on Candida species was 125 mg/ml for C. albicans, C. glabrata, and C. parapsilosis, and 250 mg/ml for C. tropicalis.

CONCLUSION

The present study can be the starting point for research activities in this direction and promises new therapies based on the use of carotenoids.

Ertapenem and Faropenem against Mycobacterium tuberculosis: in vitro testing and comparison by macro and microdilution

Background

Interest in carbapenems has been rising in the last few years due to the emergence of drug resistant tuberculosis. Ertapenem (ETP), given once a day parenteral, and faropenem (FAR), oral, have a better administration profile than meropenem (MEM), imipenem (IPM) and doripenem (DOR). The addition of amoxicillin-clavulanate (AMC) inhibits the hydrolysis by the carbapenemase present in Mycobacterium tuberculosis (MTB).

The aim of this study was to determine the in vitro activity of ETP and FAR against susceptible and resistant clinical MTB strains by two widely use methodologies, the BACTEC960 MGIT and microdilution.

Results

19 clinical isolates with different susceptibility profiles and H37Rv were included. Minimal inhibitory concentration (MIC) testing was performed using two methods of different concentrations of ETP and FAR with and without AMC.

MIC50 was 2 and 8 for FAR with and without AMC by both methods. MIC90 was > 16 and > 8 by microdilution and MGIT respectively and did not change after AMC addition.

18/20 samples were resistant to the highest concentration of ETP, with and without AMC. Half of the samples had some susceptibility to FAR; addition of AMC further reduced the MIC level in seven isolates.

10/20 isolates showed susceptibility to FAR and the addition of AMC further reduced the MIC in 7 isolates. However, most of the MICs were near the limit of effectiveness (8 μg/mL).

Resistance to FAR was associated with resistance to MEM (p = 0.04) but not to resistance profiles of other drugs, including M/XDR status.

Conclusions

The lack of ETP activity may be associated with its degradation, independent of carbapenemase, during incubation.

No susceptibility pattern to traditional drugs can predict susceptibility to FAR and susceptibility testing is not routinely available. PK/PD studies are needed as reaching the concentrations tested in these experiments may be challenging.

This work highlighted some of the limitations of carbapenem use. More evidence is needed to clarify their true impact in TB treatment and outcome, considering the financial burden, complications and microbiota changes associated with their use.