scholarly journals Susceptibility of the Candida haemulonii Complex to Echinocandins: Focus on Both Planktonic and Biofilm Life Styles and a Literature Review

2020 ◽  
Vol 6 (4) ◽  
pp. 201
Author(s):  
Lívia S. Ramos ◽  
Laura N. Silva ◽  
Marta H. Branquinha ◽  
André L. S. Santos
Keyword(s):  
Literature Review ◽  
Therapeutic Potential ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Published Data ◽  
Life Styles ◽  
Fungal Isolates ◽  
Candida Haemulonii ◽  
Almost All

Candida haemulonii complex (C. haemulonii, C. duobushaemulonii and C. haemulonii var. vulnera) is well-known for its resistance profile to different available antifungal drugs. Although echinocandins are the most effective class of antifungal compounds against the C. haemulonii species complex, clinical isolates resistant to caspofungin, micafungin and anidulafungin have already been reported. In this work, we present a literature review regarding the effects of echinocandins on this emergent fungal complex. Published data has revealed that micafungin and anidulafungin were more effective than caspofungin against the species forming the C. haemulonii complex. Subsequently, we investigated the susceptibilities of both planktonic and biofilm forms of 12 Brazilian clinical isolates of the C. haemulonii complex towards caspofungin and micafungin (anidulafungin was unavailable). The planktonic cells of all the fungal isolates were susceptible to both of the test echinocandins. Interestingly, echinocandins caused a significant reduction in the biofilm metabolic activity (viability) of almost all fungal isolates (11/12, 91.7%). Generally, the biofilm biomasses were also affected (reduction range 20–60%) upon exposure to caspofungin and micafungin. This is the first report of the anti-biofilm action of echinocandins against the multidrug-resistant opportunistic pathogens comprising the C. haemulonii complex, and unveils the therapeutic potential of these compounds.

scholarly journals Global Screening of Genomic and Transcriptomic Factors Associated with Phenotype Differences between Multidrug-Resistant and -Susceptible Candida haemulonii Strains

mSystems ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Hao Zhang ◽  
Yifei Niu ◽  
Jingwen Tan ◽  
Weixia Liu ◽  
Ming-an Sun ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Wall ◽  
Multidrug Resistance ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Cell Wall Integrity ◽  
Close Relative ◽  
Content Type ◽  
Candida Haemulonii ◽  
Resistant Strains

ABSTRACT Candida haemulonii, a close relative of Candida auris, is an emerging pathogen which frequently shows multidrug resistance especially to triazoles, the most used antifungal drugs. The mechanisms of drug resistance in C. haemulonii, however, are largely unknown. Here, we sequenced and annotated the genomes of two reference strains from the C. haemulonii complex, compared the phenotypes, genomes, and transcriptomes of a triazole-susceptible and two triazole-resistant C. haemulonii strains, and identified triazole susceptibility, morphology, fitness, and the major genetic and gene expression differences between the strains. A multidrug efflux gene, CDR1, was recurrently found to be upregulated for expression in triazole-resistant strains. Blocking the activity of Cdr1 increased the susceptibility to triazoles strikingly. Comparative transcriptome analysis also demonstrated impaired cell wall integrity, filamentous growth, and iron homeostasis in triazole-resistant strains. Finally, we also identified a zinc-binding MHR family transcription regulator gene that mutated in triazole-resistant strains spontaneously, contributing to the changes of morphology and, possibly, cell wall integrity between the strains. The study provided important clues for future studies exploring the mechanisms of multidrug resistance and related phenotypic differences of C. haemulonii strains. IMPORTANCE A comprehensive, multi-omic survey was performed to disclose the genetic backgrounds and differences between multidrug-resistant and -susceptible C. haemulonii strains. Genes were identified with mutations or significant expression differences in multidrug-resistant compared to multidrug-susceptible strains, which were mainly involved in multidrug resistance, stress fitness, and morphology. The Cdr1-encoding gene, C. haemulonii 2486 (CH_2486), was expressed at a significantly increased level in multidrug-resistant strains. Functional inhibition experiments further implicated potential roles of CH_2486 in drug resistance. A gene spontaneously mutated in resistant strains, CH_4347, was experimentally validated to influence the morphology of spores, possibly by controlling cell wall integrity.

scholarly journals Molecular Epidemiology and Microbiological Characteristics of Cryptococcus gattii VGII isolates from China

2021 ◽  
Author(s):  
xuelei zang ◽  
weixin ke ◽  
lifeng wang ◽  
hua wu ◽  
yemei huang ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Lung Tissue ◽  
Antifungal Susceptibility ◽  
Cryptococcus Gattii ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Published Data ◽  
Histopathological Analysis ◽  
Close Phylogenetic Relationship

Cryptococcus gattii (C. gattii) is a fungal pathogen that once caused an outbreak of cryptococcosis on Vancouver Island, and had spread worldwide, while few data were available in China. In this study, seven clinical isolates of C. gattii VGII were collected from 19 hospitals, Multi-locus Sequence Typing (MLST) analysis and whole-genome sequencing (WGS) was performed, and combined with published data for phylogenetic analysis. In addition, in vitro antifungal susceptibility testing, phenotypic analysis, and in vivo virulence studies were performed, subsequently, histopathological analysis of lung tissue was performed. C.gattii VGII infected patients were mainly immunocompetent male, and most of them had symptoms of central nervous system (CNS) involvement. MLST results showed that isolates from china exhibited high genetic diversity, and sequence type (ST) 7 was the major ST among the isolates. Some clinical isolates showed a close phylogenetic relationship with strains from Australia and South America. All clinical isolates did not show resistance to antifungal drugs. In addition, there was no correlation between virulence factors (temperature, melanin production, and capsule size) and virulence while in vivo experiments showed significant differences in virulence among strains. Lung fungal burden and damage to lung tissue correlated with virulence, and degree of damage to lung tissue in mice may highlight differences in virulence. Our work seeks to provide useful data for molecular epidemiology, antifungal susceptibility, and virulence differences of C. gattii VGII in China.

scholarly journals Phenotypic and genetic analysis of virulence factors in multidrug- sensitive and multidrug-resistant clinical isolates of Pseudomonas aeruginosa

2021 ◽  
Vol 10 (11) ◽  
pp. e457101120032
Author(s):  
Stephanie Targino Silva ◽  
Jailton Lobo da Costa Lima ◽  
Marcelle Aquino Rabelo ◽  
Armando Monteiro Bezerra Neto ◽  
Lílian Rodrigues Alves ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phospholipase C ◽  
Virulence Factors ◽  
Alkaline Protease ◽  
Tertiary Hospital ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Protease Production ◽  
High Level ◽  
Almost All

This study aimed to correlate the pattern of antimicrobial susceptibility, phenotypic production of virulence factors, the occurrence of virulence factors genes and the clonal profile of clinical isolates of Pseudomonas aeruginosa of a tertiary hospital in Recife-PE. The 30 clinical isolates (15 multidrug-sensitive (MDS) and 15 multidrug-resistant (MDR)) were analyzed using phenotypic methods to detect virulence factors (alkaline protease, hemolysin, phospholipase C, lipase, and pigments). The detection of the aprA, lasA, lasB, plcH, and toxA genes was performed through specific PCRs, and the clonal profile was assessed using ERIC-PCR. The results revealed cephalosporins being the class eliciting the highest percentage of resistance; the MDR isolates were all resistant. Among the MDS isolates, all were sensitive to carbapenems and quinolones. The MDR isolates produced less virulence factors such as pyocyanin and lipase, and exhibited lower expression of toxA and lasA genes, whereas the MDS isolates produced less hemolysin and phospholipase C. There was no difference between the groups for alkaline protease production and aprA gene expression. All the isolates produced pyocyanin and expressed lasB and plcH genes. A great genetic diversity was found, and it was possible to observe 28 genetic profiles. Clones were present among the MDR isolates. The occurrence of virulence factors in almost all the isolates studied suggests their high level of pathogenicity, demonstrating that this pathogen is capable of accumulating numerous virulence factors, and in some cases, is associated with multidrug resistance, which makes it difficult to treat these infections.

In Vitro Immunodetection of Prothymosin Alpha in Normal and Pathological Conditions

2020 ◽  
Vol 27 (29) ◽  
pp. 4840-4854 ◽  
Author(s):  
Chrysoula-Evangelia Karachaliou ◽  
Hubert Kalbacher ◽  
Wolfgang Voelter ◽  
Ourania E. Tsitsilonis ◽  
Evangelia Livaniou
Keyword(s):  
Mammalian Cells ◽  
Therapeutic Potential ◽  
Prothymosin Alpha ◽  
Disease States ◽  
Leading Role ◽  
Tissue Extracts ◽  
Biologic Response ◽  
Health And Disease ◽  
Almost All

Prothymosin alpha (ProTα) is a highly acidic polypeptide, ubiquitously expressed in almost all mammalian cells and tissues and consisting of 109 amino acids in humans. ProTα is known to act both, intracellularly, as an anti-apoptotic and proliferation mediator, and extracellularly, as a biologic response modifier mediating immune responses similar to molecules termed as “alarmins”. Antibodies and immunochemical techniques for ProTα have played a leading role in the investigation of the biological role of ProTα, several aspects of which still remain unknown and contributed to unraveling the diagnostic and therapeutic potential of the polypeptide. This review deals with the so far reported antibodies along with the related immunodetection methodology for ProTα (immunoassays as well as immunohistochemical, immunocytological, immunoblotting, and immunoprecipitation techniques) and its application to biological samples of interest (tissue extracts and sections, cells, cell lysates and cell culture supernatants, body fluids), in health and disease states. In this context, literature information is critically discussed, and some concluding remarks are presented.

Exploring the Chemistry and Therapeutic Potential of Triazoles: A Comprehensive Literature Review

2019 ◽  
Vol 19 (16) ◽  
pp. 1298-1368 ◽  
Author(s):  
Ankit Jain ◽  
Poonam Piplani
Keyword(s):  
Oxidative Stress ◽  
Drug Discovery ◽  
Literature Review ◽  
Structural Modification ◽  
Therapeutic Potential ◽  
Pharmacological Properties ◽  
Pharmacological Activities ◽  
Triazole Derivatives ◽  
Comprehensive Literature Review ◽  
The Common

: Triazole is a valuable platform in medicinal chemistry, possessing assorted pharmacological properties, which could play a major role in the common mechanisms associated with various disorders like cancer, infections, inflammation, convulsions, oxidative stress and neurodegeneration. Structural modification of this scaffold could be helpful in the generation of new therapeutically useful agents. Although research endeavors are moving towards the growth of synthetic analogs of triazole, there is still a lot of scope to achieve drug discovery break-through in this area. Upcoming therapeutic prospective of this moiety has captured the attention of medicinal chemists to synthesize novel triazole derivatives. The authors amalgamated the chemistry, synthetic strategies and detailed pharmacological activities of the triazole nucleus in the present review. Information regarding the marketed triazole derivatives has also been incorporated. The objective of the review is to provide insights to designing and synthesizing novel triazole derivatives with advanced and unexplored pharmacological implications.

scholarly journals Antimicrobial susceptibility, serotype distribution, virulence profile and molecular typing of piliated clinical isolates of pneumococci from east coast, Peninsular Malaysia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nurul Diana Dzaraly ◽  
Mohd Nasir Mohd Desa ◽  
AbdulRahman Muthanna ◽  
Siti Norbaya Masri ◽  
Niazlin Mohd Taib ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Antimicrobial Susceptibility ◽  
East Coast ◽  
Tertiary Hospital ◽  
Multidrug Resistant ◽  
Peninsular Malaysia ◽  
Clinical Isolates ◽  
Serotype Distribution ◽  
Antimicrobial Susceptibility Test ◽  
Conjugate Vaccines

AbstractPilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.

scholarly journals 1280. In-Vitro Activity of Cefiderocol, Imipenem/Relebactam, & Ceftazidime/Avibactam in Ceftolozane/Tazobactam Resistant Strains of Multidrug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander
Keyword(s):  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Resistance Testing ◽  
Clinical Samples ◽  
In Vitro Activity ◽  
Carbapenemase Gene ◽  
Resistant Strains

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures

Prevalence of Enterobacteriaceae spp. and its multidrug-resistant rates in clinical isolates: A two-center cross-sectional study

2021 ◽  
Author(s):  
Bahman Mirzaei ◽  
Ryhane Babaei ◽  
Zahra Norouzi Bazgir ◽  
Hamid Reza Goli ◽  
Shima Keshavarzi ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Cross Sectional Study ◽  
Clinical Isolates ◽  
Sectional Study ◽  
Cross Sectional
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