scholarly journals Virulence of Clinical Candida Isolates

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 466
Author(s):  
Martyna Mroczyńska ◽  
Anna Brillowska-Dąbrowska

The factors enabling Candida spp. infections are secretion of hydrolytic enzymes, adherence to surfaces, biofilm formation or morphological transition, and fitness attributes. The aim of this study was to investigate the correlation between known extracellular virulence factors and survival of Galleria mellonella larvae infected with clinical Candida. The 25 isolates were tested and the activity of proteinases among 24/24, phospholipases among 7/22, esterases among 14/23, hemolysins among 18/24, and biofilm formation ability among 18/25 isolates was confirmed. Pathogenicity investigation using G. mellonella larvae as host model demonstrated that C. albicans isolates and C. glabrata isolate were the most virulent and C. krusei isolates were avirulent. C. parapsilosis virulence was identified as varied, C. inconspicua were moderately virulent, and one C. palmioleophila isolate was of low virulence and the remaining isolates of this species were moderately virulent. According to our study, virulence of Candida isolates is related to the expression of proteases, hemolysins, and esterases.

Author(s):  
Fatima Abdul Hussein Mejbel

 During the period from September 2016 to December 2017,135 urine samples were collected from urinary tract infection patients attending to AL-Zahraa Hospital in AL-Najaf Governorate. The present study was conducted to isolate and identify Candida spp. isolated from urinary tract infection patients by different methods including direct examination, laboratory culture, biochemical test and by modern techniques (Api Candida kit) and determine the virulence factors phenotypic to Candida spp which involved (biofilm formation,phospholipase and germ tube). The percentage of females to males was as following, female (84) 62.2 % (21) infected and male (51) 37.8% (1) infected with all age categories. The results in this study are explain that is some Candida spp. such as C. albicans, have high susceptible to eugenole follow by phenol and umbellulone. The efficiency of some chemical substances such as (eugenole,umbellulone, and phenol) was evaluated to inhibit the growth of Candida ssp as well as some virulence factors such as biofilm formation,germ tube and phospholipase,which were studied in this research. Statistically analysis results have been significance difference between the results of the substance concentrations and the concentrations of the different other substances.


2020 ◽  
Vol 21 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Monika Staniszewska

: Fungal diseases are severe and have very high morbidity as well as up to 60% mortality for patients diagnosed with invasive fungal infection. In this review, in vitro and in vivo studies provided us with the insight into the role of Candida virulence factors that mediate their success as pathogens, such as: membrane and cell wall (CW) barriers, dimorphism, biofilm formation, signal transduction pathway, proteins related to stress tolerance, hydrolytic enzymes (e.g. proteases, lipases, haemolysins), and toxin production. The review characterized the virulence of clinically important C. albicans, C. parapsilosis, C. tropicalis, C. glabrata and C. krusei. Due to the white-opaque transition in the mating-type locus MTL-homozygous cells, C. albicans demonstrates an advantage over other less related species of Candida as a human commensal and pathogen. It was reviewed that Candida ergosterol biosynthesis genes play a role in cellular stress and are essential for Candida pathogenesis both in invasive and superficial infections. Hydrolases associated with CW are involved in the host-pathogen interactions. Adhesins are crucial in colonization and biofilm formation, an important virulence factor for candidiasis. Calcineurin is involved in membrane and CW stress as well as virulence. The hyphae-specific toxin, named candidalysin, invades mucosal cells facilitating fungal invasion into deeper tissues. Expression of this protein promotes resistance to neutrophil killing in candidiasis. The virulence factors provide immunostimulatory factors, activating dendric cells and promoting T cell infiltration and activation. Targeting virulence factors, can reduce the risk of resistance development in Candida infections.


2015 ◽  
Vol 9 (08) ◽  
pp. 857-864 ◽  
Author(s):  
Fatma Mutlu Sariguzel ◽  
Elife Berk ◽  
Ayse Nedret Koc ◽  
Hafize Sav ◽  
Gonca Demir

Introduction: The aim of study was to investigate the virulence factors of phospholipase, proteinase, esterase production and biofilm formation in Candida species isolated from patients with candidemia, and to assess their relationship with Candida genotypes derived after repetitive sequence-based polymerase chain reaction (rep-PCR) fingerprinting. Methodology: Fifty-two strains were identified to species level according to conventional methods and sequencing. The DiversiLab system was used for the genotyping. Enzyme activities and biofilm formation were evaluated using microbiological methods. Results: The 52 strains were identified as follows: 29 C. parapsilosis, 19 C. albicans, 2 C. glabrata, and 2 C. tropicalis. Phospholipase and proteinase activities were observed to have statistically significant differences between C. albicans and non-albicans Candida (NAC) strains (p < 0.05), with C. albicans strains showing higher virulence. Rep-PCR revealed eight major genotypes (A-H).The 19 C. albicans and the 33 non-albicans Candida isolates yielded seven (A-G) and four (A, B, C, H) genotypes, respectively. C. albicans strains were not shown to have a predominant genotype and showed higher phospholipase and proteinase activitiy than did NAC, regardless of genotype. Genotype H (52%) was the predominant genotype for the NAC including 27 C. parapsilosis strains, but the majority of strains showed low virulence. Conclusions: NAC species were the most common causative agent for candidemia. Genotyping showed low transmission of C. albicans strains, but transmission of C. parapsilosis was high. In candidemia, several Candida virulence factors may be responsible at the same time. However, different genotypes of Candida strains showed different virulence activity.


2020 ◽  
Vol 20 (2) ◽  
pp. 641-648
Author(s):  
Merih Kıvanç ◽  
Sevda Er

Background: In this study, it was aimed to investigate the effects of bacterial cells and cell-free filtrates of Lactobacillus acidophilus 8MR7 and Lactobacillus paracasei subspecies paracasei 10MR8 on the biofilm formation of 3 Candida tropicalis, 3 C. glabrata and 12 C. albicans isolated from the vagina and identified their virulence factors. Methods: Haemolytic activities esterase activities, and phospholipase activities as virulence factors of Candida strains were determined. Biofilm formations of these isolates were determined by Congo Red agar and microtitration plate method. Anti-biofilm activities of bacterial cells and cell-free filtrates of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 on Candida isolates were determined by the microtitration plate method. Results: Bacterial cells of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 were not very effective in the in- hibition of biofilm, whereas it has been observed that the cell-free filtrates of these bacteria inhibit the formation of biofilms of Candida strains. Although the main mechanism for inhibiting the formation of Candida spp. biofilm is the competition for adhesion, it is concluded that the substances contained in the cell-free filtrates of lactic acid bacteria are also important. Conclusion: These isolates promise hope as potential bacteria that can be used for anti-adhesion purposes in health-care materials. Keywords: Lactobacillus acidophilus; L. paracesei subspecies paracesei; vagina; biofilm.


2018 ◽  
Vol 19 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Małgorzata Gizińska ◽  
Monika Staniszewska ◽  
Zbigniew Ochal

Since candidiasis is so difficult to eradicate with an antifungal treatment and the existing antimycotics display many limitations, hopefully new sulfone derivatives may overcome these deficiencies. It is pertinent to study new strategies such as sulfone derivatives targeting the virulence attributes of C. albicans that differentiate them from the host. During infections, the pathogenic potential of C. albicans relies on the virulence factors as follows: hydrolytic enzymes, transcriptional factors, adhesion, and development of biofilms. In the article we explored how the above-presented C. albicans fitness and virulence attributes provided a robust response to the environmental stress exerted by sulfones upon C. albicans; C. albicans fitness and virulence attributes are fungal properties whose inactivation attenuates virulence. Our understanding of how these mechanisms and factors are inhibited by sulfones has increased over the last years. As lack of toxicity is a prerequisite for medical approaches, sulfones (non-toxic as assessed in vitro and in vivo) may prove to be useful for reducing C. albicans pathogenesis in humans. The antifungal activity of sulfones dealing with these multiple virulence factors and fitness attributes is discussed.


2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Angela França ◽  
Vânia Gaio ◽  
Nathalie Lopes ◽  
Luís D. R. Melo

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.


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