Boswellia serrata Extract as an Antibiofilm Agent against Candida spp.

The use of antibiotics or antifungals to control infections caused by pathogenic microorganisms is currently insufficiently effective because of their emerging resistance. Thanks to the ability of microorganisms to form a biofilm and thus increase their resistance to administered drugs even more, modern medicine faces the task of finding novel substances to combat infections caused by them. In this regard, the effects of essential oils or plant extracts are often studied. Among the relatively neglected plants is Boswellia serrata, which has a high content of biologically active boswellic acids. In this study, we focused on one of the most common nosocomial infections, which are caused by Candida species. The most common representative is C. albicans, although the number of infections caused by non-albicans species has recently been increasing. We focused on the antifungal activity of Boswellia serrata extract Bioswellix against planktonic and adhering cells of Candida albicans, Candida parapsilosis and Candida krusei. The antifungal activity against adhering cells was further explored by determining the metabolic activity of cells (MTT) and determining the total amount of biofilm using crystal violet. Boswellic acid-containing plant extract was shown to suppress the growth of a suspension population of all tested Candida species. Boswellia serrata extract Bioswellix was most effective in inhibiting C. albicans biofilm formation.

Immunity to Invasive Fungal Diseases

Invasive fungal diseases are rare in individuals with intact immunity. This, together with the fact that there are only a few species that account for most mycotic diseases, implies a remarkable natural resistance to pathogenic fungi. Mammalian immunity to fungi rests on two pillars, powerful immune mechanisms and elevated temperatures that create a thermal restriction zone for most fungal species. Conditions associated with increased susceptibility generally reflect major disturbances of immune function involving both the cellular and humoral innate and adaptive arms, which implies considerable redundancy in host defense mechanisms against fungi. In general, tissue fungal invasion is controlled through either neutrophil or granulomatous inflammation, depending on the fungal species. Neutrophils are critical against Candida spp. and Aspergillus spp. while macrophages are essential for controlling mycoses due to Cryptococcus spp., Histoplasma spp., and other fungi. The increasing number of immunocompromised patients together with climate change could significantly increase the prevalence of fungal diseases. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Changing Trends of Candida Species and Antifungal Susceptibility Profile of Candida Bloodstream Isolates: A 5-Year Retrospective Survey

Background: Candida species have emerged as one of the most common causes of bloodstream infections (BSIs). There are limited data on the distribution of Candida spp. and susceptibility by year. Objectives: In this study, we analyzed changes in the distribution of Candida spp. and their antifungal susceptibility profiles from blood cultures. Methods: Records from January 2016 to December 2020 were obtained from the microbiology laboratory in Istanbul. Antifungal susceptibility tests were performed using the VITEK 2 compact system and evaluated according to EUCAST breakpoints. A total of 241 unique candidemia episodes were included in this study. Results: Candida albicans was the predominant pathogen (n = 95, 39.42%), followed by C. parapsilosis (n = 82, 34.02%), C. glabrata (n = 18, 7.47%), C. tropicalis (n = 17, 7.05%), C. krusei (n = 15, 6.22%), and other Candida spp. (n = 14, 5.79%). There was no statistically significant difference in the percentage of episodes of Candida spp. After data analysis, a tendency to shift from C. albicans to C. parapsilosis was observed in the period analyzed in this study. Candida albicans was the most common species in intensive care units (ICUs), hematology and hemopoietic stem cell transplantation units, and surgical clinics, with C. parapsilosis predominant in medical clinics. In general, micafungin susceptibility was the highest, and fluconazole was the lowest. There was reduced sensitivity to fluconazole and voriconazole for C. albicans and C. parapsilosis over 5 years. Conclusions: Detecting changes in the distribution of Candida spp. and antifungal susceptibility over time will lead to the selection of appropriate empirical therapy and monitor phenomena of antifungal resistance. Empirical treatment with antifungal agents is associated with high costs, toxicities, and risk of antifungal resistance. Therefore, it is mandatory to determine and monitor Candida spp. and antifungal susceptibility testing to select appropriate antifungal agents.

Antifungal Activity of Natural Compounds vs. Candida spp.: A Mixture of Cinnamaldehyde and Eugenol Shows Promising In Vitro Results

Candida spp. are commensal organisms of the skin, mucous membranes, gastrointestinal tract, blood, and vagina of animals and humans. In recent decades, the incidence of human fungal infections has increased, with Candida spp. (mainly C. albicans) infections being the most frequent, and the treatment of fungal infections is still a clinical challenge. Colonization of the human gastrointestinal tract by Candida spp. is significant because infections (e.g., candidemia and vulvovaginal candidiasis) frequently arise from commensal microorganisms. The aim of this study was to test in vitro the antifungal activity and the eventual synergistic effect of five pure components of essential oils: cinnamaldehyde, α-pinene, limonene, eucalyptol, and eugenol. These compounds were tested on 18 Candida strains (15 C. albicans, 2 C. glabrata, and 1 C. lusitaniae) derived from a culture collection of vaginal clinical strains. Methods: Fungistatic activity was evaluated using the disk diffusion method. For fungicidal activity, microdilution and time–kill curve protocols were set up. The checkerboard method was chosen to evaluate a possible synergistic effect of these compounds when mixed. Results: Cinnamaldehyde and eugenol gave the best results, inhibiting all the Candida strains and showing a highly additive effect (FICI 0.625). The cinnamaldehyde inhibition zone (IZ), MIC, and MFC means were 69 mm, 50.05 mg/L, and 109.26 mg/L respectively. Cinnamaldehyde led to the total loss of viable Candida cells within 4 h. Eugenol IZ, MIC, and MFC means were 35.2 mm, 455.42 mg/L, and 690.09 mg/L, respectively. Eugenol led to the total loss of viable fungal cells within 1 h. Treatment with α-pinene inhibited 88.9% of Candida strains, with an IZ mean of 21.2 mm, a MIC mean of 195.41 mg/L, and a MFC mean of 251.27 mg/L; this compound led to the total loss of viable fungal cells only after 24 h. Limonene inhibited only 33.3% of the tested strains and eucalyptol did not produce an inhibition halo, so these compounds were not tested further. Conclusions: These characteristics, together with the well-known safety of cinnamaldehyde and eugenol for human use, make these two natural compounds the perfect candidates for the treatment of candidiasis. This was a pilot study, the purpose of which was to evaluate the best composition of a mixture to be used against intestinal and vulvovaginal candidiasis; in vivo studies are needed to confirm these very encouraging results.

Antioxidant and Antifungal Activity of the Cynophalla flexuosa (L.) J. Presl (Capparaceae) against Opportunistic Fungal Pathogens

The chemical composition of the Cynophalla flexuosa hydroethanolic extract (CFHEE) was identified and its antioxidant, antifungal and antipleomorphic activities against C. albicans and C. tropicalis strains were evaluated. Phytochemical prospecting evidenced polyphenolic and triterpenoid compounds while UPLC-MS analysis revealed the presence of Isopropyl/n-propyl-GLS; Methylpropyl-GLS/butyl-GLS; Methylbutyl-GLS; Quercetin O-di-hexoside; Quercetin-pentosyl-hexoside; Rutin; Quercetin O-glucoside; Kaempferol O-rhamnosyl-hexoside; Kaempferol O-pentosyl-hexoside and Lariciresinol hexoside. The CFHEE inhibited the effect of the DPPH● free radical, both when evaluated individually and in combination with the antifungal fluconazole. When associated with 256 μg/mL fluconazole, the extract, at concentrations from 128 μg/mL, reduced the effect of the DPPH● free radical with values ranging from 37.7% to 95.8%. The extract’s antifungal effect was considered clinically irrelevant and its combination with the antifungal triggered an antagonistic effect against the two strains, thus indicating the popular use of bravo beans in the form of teas or infusions should not be combined with the intake of the drug Fluconazole as this may lead to a reduction of its clinical effect. The extract, however, inhibited morphological changes (pleomorphism) in Candida species, preventing the development of hyphae. The CFHEE possesses an antioxidant effect and a potential pharmacological activity for the inhibition of one of the Candida spp. virulence factors.

Agents causing genital infections in routine cytological tests: frequency and characteristics of Papanicolaou smears

Urinary tract infections are responsible for most human infections, these are caused by bacteria, fungi, protozoa and associated microorganisms. The goal of this study was to determine the rate of vaginal infection-causing agents in routine cytological exams and also to evaluate the characteristics of positive tested Pap smears. A retrospective documental with descriptive aspect research was performed in a Clinical Pathology laboratory from Maceió-AL. The results of the Pap smears exams for Trichomonas vaginalis, Gardnerella vaginalis, Candida spp and HPV were arranged in a database as well as other data such as bacterial, protozoan, fungal and viral coinfections. The sample was composed by 18.645 women who have undergone Pap smear exams from 2013 to 2017. Of these analyzed exams, 27.4% in 2013, 10.9% in 2014, 10.6% in 2015, 15.2% in 2016 and 13.67% in 2017 were within normal range, however more than half of these exams presented some infections caused by unspecific or microbiological agents. By analyzing all the reports, 4.073 (21.84%) presented inflammations caused by some species of infectious agent with the following rate order: G. vaginalis and T. vaginalis. Furthermore, it was possible to confirm high rates of coinfection by and Candida spp. The rate of genital infections in this study highlights that there is a public health matter that must be controlled, which points a greater need for monitoring, guidance and actions towards greater awareness in order to prevent these problems.

Aspectos da microbiota vaginal e a relação com a candidíase em mulheres gestantes: uma revisão de literatura

A microbiota vaginal possui papel importante no equilíbrio, na manutenção e prevenção da saúde vaginal das mulheres, possuindo vasta quantidade de microrganismos. Candida spp. é uma das espécies de fungos que mais causa infecções nos seres humanos. Durante a gravidez, onde os níveis hormonais estão elevados e ocorre variação do pH vaginal, esses microrganismos podem colonizar a vagina e consequentemente propiciar uma infecção. O presente trabalho visa avaliar os aspectos da microbiota vaginal e sua correlação com a candidíase vulvovaginal na gravidez, e suas formas de diagnóstico. O presente estudo caracteriza-se por ser uma revisão integrativa de literatura, onde foram utilizadas as plataformas científicas PubMed, Google Acadêmico, Medline e Scielo Artigos como fonte de dados. Os dados gerados na pesquisa demonstraram a importância da compreensão sobre a microbiota vaginal. Além de evidenciar a importância de estudos a respeito da candidíase vulvovaginal em gestantes, e como outras espécies de Candida sp. estão afetando e elevando os índices de pacientes com corrimento vaginal, além da Candida albicans, a qual é a espécie mais estudada desse gênero. Também observar a relevância do diagnóstico dessa enfermidade. Concluímos assim que o conhecimento dos aspectos clínicos da sintomalogia, principalmente, durante a gravidez é uma importante ferramenta para o diagnóstico precoce durante o período pré-natal. A transmissão vertical se mostra presente nas infecções em recém-nascido. A espécie mais evidente desse gênero é a C. albicans contudo, as espécies de Candida não albicans estão cada vez mais presentes nas infecções causadas pelo gênero Candida spp.

Antifungal Activity of N-(4-Halobenzyl)amides against Candida spp. and Molecular Modeling Studies

Fungal infections remain a high-incidence worldwide health problem that is aggravated by limited therapeutic options and the emergence of drug-resistant strains. Cinnamic and benzoic acid amides have previously shown bioactivity against different species belonging to the Candida genus. Here, 20 cinnamic and benzoic acid amides were synthesized and tested for inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019. Five compounds inhibited the Candida strains tested, with compound 16 (MIC = 7.8 µg/mL) producing stronger antifungal activity than fluconazole (MIC = 16 µg/mL) against C. krusei ATCC 14243. It was also tested against eight Candida strains, including five clinical strains resistant to fluconazole, and showed an inhibitory effect against all strains tested (MIC = 85.3–341.3 µg/mL). The MIC value against C. krusei ATCC 6258 was 85.3 mcg/mL, while against C. krusei ATCC 14243, it was 10.9 times smaller. This strain had greater sensitivity to the antifungal action of compound 16. The inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019 was also achieved by compounds 2, 9, 12, 14 and 15. Computational experiments combining target fishing, molecular docking and molecular dynamics simulations were performed to study the potential mechanism of action of compound 16 against C. krusei. From these, a multi-target mechanism of action is proposed for this compound that involves proteins related to critical cellular processes such as the redox balance, kinases-mediated signaling, protein folding and cell wall synthesis. The modeling results might guide future experiments focusing on the wet-lab investigation of the mechanism of action of this series of compounds, as well as on the optimization of their inhibitory potency.

CHARACTERISTICS OF THE COMPOSITION OF GINGIVAL POCKETS MICRFLORA ISOLATED FROM PATIENTS WITH PURULENT INFLAMMATORY DISEASES IN THE PERIODONTAL TISSUES

The problem of the purulent inflammatory disorders of periodontal tissues (PIDPT) at the present time is extremely prevalent. According to the World Health Organization (WHO), around 80% of people suffer from periodontal diseases, and the disease incidence among young people increases significantly and reaches up to 80-95 %. The aim of the present research was to study the composition of microflora of gingival pockets in patients with purulent inflammatory periodontal diseases (PIDPT) in order to establish the specific weight of the determined microbial associations. Materials and methods. Microbiological researches included isolation and identification of bacteria that were present in the gingival pockets of patients with different types of PIDPT. Identification of anaerobic microorganisms and associated microflora was carried out with the help of commonly used classical bacteriological methods, with determination of biochemical properties of the microorganisms cultures using APІ and ANAEROtest 23. Results. There were 192 patients studied in total, all aged older than 20 with diagnoses acute and chronical periodontitis, aggressive periodontitis, hypertrophic pulpitis, granulating periodontitis, parodontopathy, and local periodontitis with a presence of fistula. During the analysis of composition of the microflora isolated from periodontal tissue in patients with PIDPT, the following pathogens were isolated most frequently during the bacteriological research: Streptococcus spp., Staphylococcus spp., Neisseria spp., Stomatococcus spp., and Enterococcus spp. (58%). The quantity of periodontally pathogenic microorganisms was constituted 19,3% from the total quantity of isolated streains (81 isolates). The most numerous group was determined to be the “orange” complex (59,3%) – isolates of Prevotella melaninogenica, Fusobacterium nucleatum, Parvimonas micra. The least numerous was the group of “green” complex - (2,5 %) – Streptococcus mitis. Periodontally pathogenic representatives of microbiota in all cases were isolated as a part of associations with other bacteria. The presented materials signified that the periodontally pathogenic agents of the “red” and “orange” complexes were isolated together with representatives of Streptococcus spp - 33 (56,0 %) associations; Staphylococcus spp - 11(18,6%) – associations. Also in 13 cases (22,1 %) of associations the associated flora was represented by Candida spp. fungi. Conclusions. In course of the research, 4 species of “red” and “orange” complexes were identified, and the quantity of different associations there were present in was significant. There were 22 associations determined. The obtained date concerning microbial associates in the content of gingival pockets in PIDPT show the necessity of individual approach during treatent of this patient group, with taking into account the microbial diversity.