Evaluation of overtime phenotypic variation of yeasts in chronic vulvovaginal candidosis cases

2021 ◽  
Author(s):  
Paula Faria-Gonçalves ◽  
Carlos Gaspar ◽  
Ana Sofia Oliveira ◽  
Rita Palmeira-de-Oliveira ◽  
Teresa Gonçalves ◽  
...  
Keyword(s):  
Dna Analysis ◽  
Automated Analysis ◽  
Microtiter Plate ◽  
Vaginal Mucosa ◽  
Candida Spp ◽  
Microtiter Plate Assay ◽  
Two Factors ◽  
Vulvovaginal Candidosis ◽  
Two Parameters ◽  
Resistance Rates

Abstract Chronic vulvovaginal candidosis results either from reinfection or from the ability of Candida spp. to persist in the vulva and/or vagina. Persistence is usually associated with increased antifungal (mainly azoles) resistance rates, which can explain treatment failure, and/or increased expression of virulence factors by Candida spp. The aim of this study was to assess the mechanisms leading to Candida spp persistence, by studying sequential isolates from women with chronic vulvovaginal candidosis, focusing on strains genotypes, azole resistance, and ability to form biofilms along the period of clinical evaluation. The strains were identified at species level by automated analysis of biochemical profiles and molecular typing evaluated by polymorphic DNA analysis. The capacity to form biofilm was assessed with a microtiter plate assay. Fluconazole susceptibility was determined by the microdilution broth assay at both pH 7 (following the recommended guideline) and pH 4.5 (as representative of vaginal pH). We studied samples from 17 clinically recurrent cases. In 53% of the chronic cases there were two or more isolates that had a phylogenetic relationship while the remaining (47%) were caused by different species. In those cases where related strains were involved in recurrence, we verified an increase in MIC at pH 7 and also an increased capacity to form biofilms over time. Significant correlation between these two parameters was observed only in cases caused by C. glabrata, evidencing the importance of these two factors to enhance persistence in the vaginal mucosa for this particular species.

scholarly journals Relationship between the Biofilm-Forming Capacity and Antimicrobial Resistance in Clinical Acinetobacter baumannii Isolates: Results from a Laboratory-Based In Vitro Study

2021 ◽  
Vol 9 (11) ◽  
pp. 2384
Author(s):  
Matthew Gavino Donadu ◽  
Vittorio Mazzarello ◽  
Piero Cappuccinelli ◽  
Stefania Zanetti ◽  
Melinda Madléna ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
In Vitro Study ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
Antibiotic Resistant ◽  
Significant Difference ◽  
Two Factors ◽  
Resistance Rates ◽  
The Relationship

The relationship between the multidrug-resistant (MDR) phenotype and biofilm-forming capacity has been a topic of extensive interest among biomedical scientists, as these two factors may have significant influence on the outcomes of infections. The aim of the present study was to establish a possible relationship between biofilm-forming capacity and the antibiotic-resistant phenotype in clinical Acinetobacter baumannii (A. baumannii) isolates. A total of n = 309 isolates were included in this study. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out. The capacity of isolates to produce biofilms was assessed using a crystal violet microtiter-plate-based method. Resistance rates were highest for ciprofloxacin (71.19%; n = 220), levofloxacin (n = 68.61%; n = 212), and trimethoprim-sulfamethoxazole (n = 66.02%; n = 209); 42.72% (n = 132) of isolates were classified as MDR; 22.65% (n = 70) of tested isolates were positive in the modified Hodge-test; the overexpression of efflux pumps had significant effects on the susceptibilities of meropenem, gentamicin, and ciprofloxacin in 14.24% (n = 44), 6.05% (n = 19), and 27.51% (n = 85), respectively; 9.39% (n = 29), 12.29% (n = 38), 22.97% (n = 71), and 55.35% (n = 170) of isolates were non-biofilm-producing and weak, moderate, and strong biofilm producers, respectively. A numerical, but statistically not significant, difference was identified between the MDR and non-MDR isolates regarding their biofilm-forming capacity (MDR: 0.495 ± 0.309 vs. non-MDR: 0.545 ± 0.283; p = 0.072), and no association was seen between resistance to individual antibiotics and biofilm formation. Based on numerical trends, MER-resistant isolates were the strongest biofilm producers (p = 0.067). Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of A. baumannii infections.

scholarly journals Drug Targeting Mycobacterium tuberculosis Cell Wall Synthesis: Development of a Microtiter Plate-Based Screen for UDP-Galactopyranose Mutase and Identification of an Inhibitor from a Uridine-Based Library

2003 ◽  
Vol 47 (1) ◽  
pp. 378-382 ◽  
Author(s):  
Michael S. Scherman ◽  
Katharine A. Winans ◽  
Richard J. Stern ◽  
Victoria Jones ◽  
Carolyn R. Bertozzi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Drug Targeting ◽  
Enzyme Inhibitor ◽  
Microtiter Plate ◽  
Biosynthetic Enzyme ◽  
Cell Wall Synthesis ◽  
Chemical Library ◽  
Microtiter Plate Assay ◽  
Plate Assay

ABSTRACT A microtiter plate assay for UDP-galactopyranose mutase, an essential cell wall biosynthetic enzyme of Mycobacterium tuberculosis, was developed. The assay is based on the release of tritiated formaldehyde from UDP-galactofuranose but not UDP-galactopyranose by periodate and was used to identify a uridine-based enzyme inhibitor from a chemical library.

scholarly journals Effect of S-PRG Eluate on Biofilm Formation and Enzyme Activity of Oral Bacteria

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Masahiro Yoneda ◽  
Nao Suzuki ◽  
Yosuke Masuo ◽  
Akie Fujimoto ◽  
Kosaku Iha ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Composite Resin ◽  
Fusobacterium Nucleatum ◽  
Microtiter Plate ◽  
Oral Bacteria ◽  
Gelatin Film ◽  
Glass Ionomer ◽  
Microtiter Plate Assay ◽  
Substrate Hydrolysis ◽  
Adherence Ability

Recently, the antibacterial activity of a composite resin containing prereacted glass ionomer (S-PRG) filler was revealed. We examined the effect of an S-PRG eluate on various biologic activities ofStreptococcus mutansandPorphyromonas gingivalis. Adherence ability ofS. mutanswas evaluated by microtiter plate assay; protease and gelatinase activities ofP. gingivaliswere examined by synthetic substrate hydrolysis and gelatin film spot assay, respectively. Coaggregation ofP. gingivaliswithFusobacterium nucleatumwas also examined. S-PRG eluate was found to suppress streptococcal adherence. S-PRG eluate inhibited the protease and gelatinase activities ofP. gingivalisand the coaggregation betweenP. gingivalisandF. nucleatum. These results indicate that S-PRG eluate suppresses streptococcal adherence and inhibits the protease and coaggregation activities ofP. gingivalis. These findings may prompt research into novel strategies for preventing caries and periodontitis.

Evaluation of the Role of Staphylococci in the Pathomechanism of Conjunctivitis

2021 ◽  
Author(s):  
Ewa Jasińska ◽  
Agnieszka Bogut ◽  
Agnieszka Magryś ◽  
Alina Olender
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microtiter Plate ◽  
Host Cells ◽  
Diffusion Method ◽  
Microtiter Plate Assay ◽  
Low Prevalence

Abstract Purpose: Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity.Methods: The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtiter plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay.Results: The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE.Conclusions: Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.

Immobilized Enzyme-Based Microtiter Plate Assay for Glucose in Foods

1996 ◽  
Vol 44 (12) ◽  
pp. 3858-3863 ◽  
Author(s):  
Hiroyuki Ukeda ◽  
Yoshihiro Fujita ◽  
Miki Ohira ◽  
Masayoshi Sawamura
Keyword(s):  
Immobilized Enzyme ◽  
Microtiter Plate ◽  
Microtiter Plate Assay ◽  
Plate Assay

scholarly journals Antifungal Susceptibility and Biofilm Production of Candida spp. Isolated from Clinical Samples

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Munmun B. Marak ◽  
Biranthabail Dhanashree
Keyword(s):  
Antifungal Susceptibility ◽  
Clinical Information ◽  
Antibiotic Use ◽  
Microtiter Plate ◽  
Vaginal Swab ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Candida Spp ◽  
Disk Diffusion Method ◽  
Biofilm Production

Objective. The study aims to speciate clinical Candida isolates and detect their biofilm-forming ability and antifungal resistance. Methods. All the Candida spp. isolated from different clinical samples like pus, urine, blood, and body fluid were included in the study. Biofilm production was tested by the microtiter plate method. Antifungal susceptibility was studied by the disk diffusion method. Patient’s demographic details such as age, sex, and clinical information were collected. Presence of other risk factors such as diabetes mellitus, history of antibiotic use, and any urinary tract instrumentations was also recorded. Results. Among 90 Candida species isolated, most predominant species was found to be C. albicans (45.5%) followed by C. tropicalis (28.88%), C. krusei (20%), C. glabrata (3.33%), and C. parapsilosis (2.22%). Candida spp. were isolated from urine (43%), BAL/sputum (18.88%), high vaginal swab (8.88%), suction tips (7.77%), blood and wound swabs (6.66%), pus (3.33%), bile aspirate (2.22%), and deep tissue (1.11%). A larger number of females were affected than males, and the age group of 51 to 60 years was more susceptible to candidiasis. A higher number of C. albicans isolates produced biofilm followed by C. parapsilosis, C. tropicalis, and C. krusei. However, C. glabrata showed no biofilm production in our study. All Candida isolates were 100% sensitive to amphotericin B. Voriconazole was the next effective drug with 81.11% susceptibility. 24.44% of strains were resistant to fluconazole. Conclusion. Speciation of Candida isolates, detection of ability to form the biofilm, and monitoring of antifungal susceptibility testing are necessary for appropriate treatment.

scholarly journals GC-MS Analysis and Antimicrobial Assessment of Syzygium cumini (L.) Skeels Seed Ethanol Extract

2021 ◽  
pp. 271-283
Author(s):  
S. Mabel Parimala ◽  
A. Antilin Salomi
Keyword(s):  
Bacterial Species ◽  
Ethanol Extract ◽  
Microtiter Plate ◽  
Salmonella Typhi ◽  
Fungal Species ◽  
Gas Chromatography Mass Spectrometry ◽  
Diffusion Method ◽  
Syzygium Cumini ◽  
Microtiter Plate Assay ◽  
Agar Well Diffusion Method

People use plants to treat infections, and this has led to search of antimicrobials from medicinal plants. In this work, we evaluated the ethanol extract of Syzygium cumini seeds for their antibacterial and antifungal activities. Extraction was performed by maceration method using ethanol. The antimicrobial efficacy of the extract was assessed by agar well diffusion method against ten bacterial species, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Staphylococcus aureus and Streptococcus mutans, and five fungal species, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Mucor sp. Minimum inhibitory concentrations (MICs) of the extract were determined by resazurin microtiter plate assay.  Phytochemicals in the extract was identified by gas chromatography mass spectrometry (GC-MS) information.  In agar well diffusion method, Gram-negative bacteria such as P. aeruginosa and S. marcescens, Gram-positive bacteria such as B. subtilis and E. faecalis and fungi A. fumigatus were more susceptible showing larger zones of inhibition.  In resazurin method, low MICs were recorded for bacteria, B. cereus (<7.8 µg) and P. aeruginosa (15.6 µg) and fungi, A. fumigatus (31.2 µg).  Fifteen compounds were identified by GC-MS profiling of the extract.  The antimicrobial activity of the extract can be rightly related to the secondary metabolites in the ethanol extract of Syzygium cumini seeds.

scholarly journals Quantitative measurement of antibiotic resistance in Mycobacterium tuberculosis reveals genetic determinants of resistance and susceptibility in a target gene approach

2021 ◽  
Author(s):  
◽  
Joshua J Carter
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Quantitative Measurement ◽  
Target Gene ◽  
Microtiter Plate ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
World Health ◽  
Genetic Determinants ◽  
Microtiter Plate Assay ◽  
Health Organization

AbstractThe World Health Organization goal of universal drug susceptibility testing for patients with tuberculosis is most likely to be achieved through molecular diagnostics; however, to date these have focused largely on first-line drugs, and always on predicting binary susceptibilities. Here, we used whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration in 15,211 Mycobacterium tuberculosis patient isolates from 27 countries across five continents.This work identifies 449 unique MIC-elevating genetic determinants across thirteen drugs, as well as 91 mutations resulting in hypersensitivity for eleven drugs. Our results provide a guide for further implementation of personalized medicine for the treatment of tuberculosis using genetics-based diagnostics and can serve as a training set for novel approaches to predict drug resistance.

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