scholarly journals Microscopic Evaluation, Molecular Identification, Antifungal Susceptibility, and Clinical Outcomes inFusarium,Aspergillusand, Dematiaceous Keratitis

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Devarshi U. Gajjar ◽  
Anuradha K. Pal ◽  
Bharat K. Ghodadra ◽  
Abhay R. Vasavada
Keyword(s):  
Clinical Outcomes ◽  
Amphotericin B ◽  
Molecular Identification ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Its Region ◽  
Fungal Species ◽  
Fungal Keratitis ◽  
Accurate Identification ◽  
Microscopic Evaluation

Purpose.Fusarium,Aspergillus, and Dematiaceous are the most common fungal species causing keratitis in tropical countries. Herein we report a prospective study on fungal keratitis caused by these three fungal species.Methodology. A prospective investigation was undertaken to evaluate eyes with presumed fungal keratitis. All the fungal isolates (n=73) obtained from keratitis infections were identified using morphological and microscopic characters. Molecular identification using sequencing of the ITS region and antifungal susceptibility tests using microdilution method were done. The final clinical outcome was evaluated in terms of the time taken for resolution of keratitis and the final visual outcome. The results were analyzed after segregating the cases into three groups, namely,Fusarium,Aspergillus, and Dematiaceous keratitis.Results. Diagnosis of fungal keratitis was established in 73 (35.9%) cases out of 208 cases. The spectra of fungi isolated wereFusariumspp. (26.6%),Aspergillusspp. (21.6%), and Dematiaceous fungi (11.6%). The sequence of the ITS region could identify theFusariumandAspergillusspecies at the species complex level, and the Dematiaceous isolates were accurately identified. Using antifungal agents such as fluconazole, natamycin, amphotericin B, and itraconazole, the minimum inhibitory concentrations (MICs) forFusariumspp. were >32 μg/mL, 4–8 μg/mL, 0.5–1 μg/mL, and >32 μg/mL, respectively. Antifungal susceptibility data showed thatCurvulariaspp. was highly resistant to all the antifungal agents. Overall, natamycin and amphotericin B were found to be the most effective antifungal agents. The comparative clinical outcomes in all cases showed that the healing response in terms of visual acuity of the Dematiaceous group was significantly good when compared with theFusariumandAspergillusgroups (P<0.05). The time required for healing in theFusariumgroup was statistically significantly less when compared with theAspergillusand Dematiaceous groups.Conclusion. This study demonstrates important differences in microscopic features of scraping material and antifungal susceptibility between the three groups. Early and accurate identification coupled with the MIC data, and thereby appropriate treatment is crucial for complete recovery.

scholarly journals Antifungal sensitivity profile of Fusarium spp. resulting keratitits

2017 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Morphological Characteristics ◽  
Fungal Keratitis ◽  
Morphological Identification ◽  
Fusarium Spp ◽  
Sensitivity Testing ◽  
Resistant Strains ◽  
Emergence Of Resistance

Fungal keratitis is an important cause of visual impairment and blindness. Genus Fusarium is a leading cause for fungal keratitis and it has higher degree of resistance to antifungal agents. Our objectives were to identify Fusarium spp. isolated from corneal specimens (received at Dept. of Mycology - MRI from 2013-2016) up to species level and to determine antifungal susceptibility pattern of them. All Fusarium isolates (51) obtained from specimens of patients with keratitis were included in the study. Speciation was done using morphological characteristics of fungi. Antifungal sensitivity testing was done according to CLSI M 51- A guideline, against amphotericin B (10 µg), itraconazole (10 µg). and voriconazole (1 µg). Majority of the isolates were F. solani complex (n=24). Three isolates were difficult to speciate morphologically. Significant number of Fusarium isolates had inhibitory zone diameters (IZD) less than tentative zone diameter epidemiological cut off values (TZD ECVs) for both itraconazole and amphotericin B, indicating emergence of resistant strains against these drugs. Forty five isolates (97.82%) had IZD more than corresponding TZD ECV for voriconazole. All F. solani complexes had IZD less than TZD ECVs for itraconazole. Morphological identification cannot be used as the only method for speciation of Fusarium isolates. Antifungal sensitivity testing should be done for Fusarium isolates from keratitis patients as emergence of resistance strains is not uncommon against commonly used antifungal agents.

scholarly journals Distribution and antifungal susceptibility of Candida species in patients with increased risk for fungal infections

2016 ◽  
Vol 62 (1) ◽  
pp. 65-76
Author(s):  
Gordana Mirchevska ◽  
Maja Jurhar Pavlova ◽  
Elena Trajkovska-Dokic ◽  
Zaklina Cekovska ◽  
Gordana Jankoska ◽  
...  
Keyword(s):  
Blood Culture ◽  
Amphotericin B ◽  
Critically Ill Patients ◽  
Candida Species ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Clinical Specimens ◽  
Fourth Group ◽  
Increased Risk

Candida species are opportunistic yeasts that can be a serious threat for immunocompromised and critically ill patients, and a cause for increased morbidity and mortality in hospitalized patients. The aim of this study was to determine the frequency and distribution of different Candida species in clinical specimens in patients with increased risk for fungal infections, and to determine the antifungal susceptibility profile of invasive Candida species to antifungal agents. During a two year period, clinical specimens from 120 patients divided into 4 groups were analysed at the Institute of microbiology and parasitology, Faculty of Medicine, Skopje, Republic of Macedonia. Each of these 4 groups consisted of specimens from 30 patients, with primary immune deficiency, critically ill patients treated in the intensive care units (ICU), patients with mucosal candidiasis only, and patients with cystic fibrosis. All specimens were investigated with conventional mycological methods. Identification of Candida species was performed with VITEK-2 system (bioMérieux, France). E-test strips of fluconazole, voriconazole, amphotericin B and caspofungin (AB bioMerieux, France) were used for determination of the antifungal susceptibility profile. In this study, a total of 115 isolates of Candida species were confirmed in different clinical specimens (91 isolates from mucosal surfaces and 24 isolates from blood culture). Colonisation of mucosal membranes of gastrointestinal, respiratory and/or urinary tracts was registered in 56.67% (17/30), 56.67% (17/30), 90% (27/30) and 100% (30/30) of the specimens in the first, second, third and fourth group respectively. In all four groups of patients, the following Candida species were confirmed: C. albicans - 55%, C. glabrata - 17.6%, C. parapsilosis - 7.7%, C. tropicalis - 6.6%, unidentified Candida species - 4.4%, C. dubliniensis - 3.3%, C. kefyr - 2.2%, and one isolate of C. rugosa, C. pelliculosa and C. krusei each. Positive blood culture was registered in 23.33% specimens from the first group, 43.33% in the second group, 23.08% of the third group, and in one specimen of the fourth group. The most frequent isolates from blood culture were C. tropicalis and C. krusei, followed by C. albicans, C. parapsilosis and C. tropicalis, and in the second group C. albicans and C. pelliculosa were equally distributed, followed by C. parapsilosis and C. glabrata. All invasive isolates of Candida species were susceptible to amphotericin B, voriconazole and caspofungin. Resistance to fluconazole was registered in 8.3% (2/24) of all confirmed Candida species. Dose-dependent susceptibility to fluconazole was confirmed in 46% (11/24) of the isolates. Our study confirms high prevalence of colonisation and candidemia with non-albicans Candida species. Resistance to antifungal agents was registered only in two isolates of C. krusei. An epidemiological study is necessary for surveillance of dynamics of candidemia and antifungal susceptibility profile of invasive isolates of Candida species in our patients.

Etest ECVs/ECOFFs for detection of resistance in prevalent and three non-prevalent Candida spp. to triazoles and amphotericin B and Aspergillus spp. to caspofungin: Further assessment of modal variability

2021 ◽  
Author(s):  
A. Espinel-Ingroff ◽  
M. Sasso ◽  
J. Turnidge ◽  
M. Arendrup ◽  
F. Botterel ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Point Mutations ◽  
Fungal Species ◽  
Candida Spp ◽  
Pichia Kudriavzevii ◽  
Routine Testing ◽  
Data Points

Susceptibility testing is an important tool in the clinical setting; its utility is based on the availability of categorical endpoints, breakpoints (BPs) or epidemiological cutoff values (ECVs/ECOFFs). CLSI and EUCAST have developed antifungal susceptibility testing, BPs and ECVs for some fungal species. Although the Concentration Gradient Strip BioMerieux Etest is useful for routine testing in the clinical laboratory, ECVs are not available for all agent/species; the lack of clinical data precludes development of BPs. We re-evaluated and consolidated Etest data points from three previous studies, and included new data. We defined ECOFFinder Etest ECVs for three sets of species/agent combinations: fluconazole, posaconazole and voriconazole and 8 Candida spp.; amphotericin B and 3 non-prevalent Candida spp.; and caspofungin and 5 Aspergillus spp. The total of Etest MICs from 23 laboratories (Europe, the Americas, South Africa) included (antifungal agent/dependent): 17,242 Candida albicans , 244 C. dubliniensis , 5,129 C. glabrata species complex (SC), 275 C. guilliermondii ( Meyerozyma guilliermondii ), 1,133 C. krusei ( Pichia kudriavzevii ), 933 C. kefyr ( Kluyveromyces marxianus ), 519 C. lusitaniae ( Clavispora lusitaniae ), 2,947 C. parapsilosis SC, 2,214 C. tropicalis , 3,212 Aspergillus fumigatus , 232 A. flavus , 181 A. niger , and 267 A. terreus SC isolates. Triazole MICs for 66 confirmed non-wild-type (non-WT) Candida isolates were available ( ERG11 point mutations). Distributions fulfilling CLSI ECV criteria were pooled and ECOFFinder Etest ECVs were established for triazoles (9 Candida spp.); amphotericin B (3 less-prevalent Candida spp.) and caspofungin (4 Aspergillus spp.). Etest fluconazole ECVs could be good detectors of Candida non-WT isolates (59/61 Non-WT: 4 of 6 species).

scholarly journals In Vitro Activity of Chlorhexidine Compared with Seven Antifungal Agents against 98 Fusarium Isolates Recovered from Fungal Keratitis Patients

2019 ◽  
Vol 63 (8) ◽  
Author(s):  
Claudy Oliveira dos Santos ◽  
Eva Kolwijck ◽  
Henrich A. van der Lee ◽  
Marlou C. Tehupeiory-Kooreman ◽  
Abdullah M. S. Al-Hatmi ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Culture Collection ◽  
Fungal Keratitis ◽  
Molecular Techniques ◽  
Temperate Climate ◽  
Eye Drops ◽  
Fungal Culture ◽  
Content Type

ABSTRACT Fungal keratitis is a common but severe eye infection in tropical and subtropical areas of the world. In regions with a temperate climate, the frequency of infection is rising in patients with contact lenses and following trauma. Early and adequate therapy is important to prevent disease progression and loss of vision. The management of Fusarium keratitis is complex, and the optimal treatment is not well defined. We investigated the in vitro activity of chlorhexidine and seven antifungal agents against a well-characterized collection of Fusarium isolates recovered from patients with Fusarium keratitis. The fungus culture collection of the Center of Expertise in Mycology Radboudumc/CWZ was searched for Fusarium isolates that were cultured from cornea scrapings, ocular biopsy specimens, eye swabs, and contact lens fluid containers from patients with suspected keratitis. The Fusarium isolates that were cultured from patients with confirmed keratitis were all identified using conventional and molecular techniques. Antifungal susceptibility testing was performed according to the EUCAST broth microdilution reference method. The antifungal agents tested included amphotericin B, voriconazole, posaconazole, miconazole, natamycin, 5-fluorocytosine, and caspofungin. In addition, the activity of chlorhexidine was determined. The fungal culture collection contained 98 Fusarium isolates of confirmed fungal keratitis cases from 83 Dutch patients and 15 Tanzanian patients. The isolates were collected between 2007 and 2017. Fusarium oxysporum (n = 24, 24.5%) was the most frequently isolated species followed by Fusarium solani sensu stricto (n = 18, 18.4%) and Fusarium petroliphilum (n = 11, 11.2%). Amphotericin B showed the most favorable in vitro inhibition of Fusarium species followed by natamycin, voriconazole, and chlorhexidine, while 5-fluorocytosine, posaconazole, miconazole, and caspofungin showed no relevant inhibiting effect. However, chlorhexidine showed fungicidal activity against 90% of F. oxysporum strains and 100% of the F. solani strains. Our study supports the clinical efficacy of chlorhexidine and therefore warrants its further clinical evaluation for primary therapy of fungal keratitis, particularly in low and middle income countries where fungal keratitis is much more frequent and, currently, antifungal eye drops are often unavailable.

scholarly journals Increasing Prevalence of Multidrug-Resistant Candida haemulonii Species Complex among All Yeast Cultures Collected by a Reference Laboratory over the Past 11 Years

2020 ◽  
Vol 6 (3) ◽  
pp. 110 ◽  
Author(s):  
Soraia Lopes Lima ◽  
Elaine Cristina Francisco ◽  
João Nóbrega de Almeida Júnior ◽  
Daniel Wagner de Castro Lima Santos ◽  
Fabiane Carlesse ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Species Complex ◽  
Antifungal Susceptibility ◽  
Its Region ◽  
Multidrug Resistant ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Reference Laboratory ◽  
Yeast Cultures ◽  
Candida Haemulonii

There is worldwide concern with the increasing rates of infections due to multiresistant Candida isolates reported in tertiary medical centers. We checked for historical trends in terms of prevalence rates and antifungal susceptibility of the Candida haemulonii species complex in our yeast stock culture collected during the last 11 years. The isolates were identified by sequencing the rDNA internal transcribed spacer (ITS) region, and antifungal susceptibility tests for amphotericin B, voriconazole, fluconazole, anidulafungin, and 5-fluorocytosine were performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method. A total of 49 isolates were identified as Candida haemulonii sensu stricto (n = 21), followed by C. haemulonii var. vulnera (n = 15) and C. duobushaemulonii (n = 13), including 38 isolates cultured from patients with deep-seated Candida infections. The prevalence of the C. haemulonii species complex increased from 0.9% (18 isolates among 1931) in the first period (December 2008 to June 2013) to 1.7% (31 isolates among 1868) in the second period (July 2014 to December 2019) of analysis (p = 0.047). All isolates tested exhibited high minimum inhibition concentrations for amphotericin B and fluconazole, but they remained susceptible to 5-fluorocytosine and anidulafungin. We were able to demonstrate the increased isolation of the multiresistant Candida haemulonii species complex in our culture collection, where most isolates were cultured from patients with deep-seated infections.

scholarly journals Comparison of the Sensititre YeastOne and CLSI M38-A2 Microdilution Methods in Determining the Activity of Amphotericin B, Itraconazole, Voriconazole, and Posaconazole against Aspergillus Species

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Hsuan-Chen Wang ◽  
Ming-I Hsieh ◽  
Pui-Ching Choi ◽  
Chi-Jung Wu
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Aspergillus Species ◽  
Broth Microdilution ◽  
Content Type

ABSTRACT This study compared the YeastOne and reference CLSI M38-A2 broth microdilution methods for antifungal susceptibility testing of Aspergillus species. The MICs of antifungal agents were determined for 100 Aspergillus isolates, including 54 Aspergillus fumigatus (24 TR34/L98H isolates), 23 A. flavus, 13 A. terreus, and 10 A. niger isolates. The overall agreement (within 2 2-fold dilutions) between the two methods was 100%, 95%, 92%, and 90% for voriconazole, posaconazole, itraconazole, and amphotericin B, respectively. The voriconazole geometric mean (GM) MICs were nearly identical for all isolates using both methods, whereas the itraconazole and posaconazole GM MICs obtained using the YeastOne method were approximately 1 dilution lower than those obtained using the reference method. In contrast, the amphotericin B GM MIC obtained using the YeastOne method was 3.3-fold higher than that observed using the reference method. For the 24 A. fumigatus TR34/L98H isolates assayed, the categorical agreement (classified according to the CLSI epidemiological cutoff values) was 100%, 87.5%, and 83.3% for itraconazole, voriconazole, and posaconazole, respectively. For four A. niger isolates, the itraconazole MICs were >8 μg/ml using the M38-A2 method due to trailing growth, whereas the corresponding itraconazole MICs obtained using the YeastOne method were all ≤0.25 μg/ml without trailing growth. These data suggest that the YeastOne method can be used as an alternative for azole susceptibility testing of Aspergillus species and for detecting the A. fumigatus TR34/L98H isolates but that this method fails to detect A. niger isolates exhibiting trailing growth with itraconazole. Additionally, for isolates with azole MICs that approach or that are at susceptibility breakpoints or with high amphotericin B MICs detected using the YeastOne method, further MIC confirmation using the reference CLSI method is needed.

Management of Candidiasis in Critically Ill Patients

2002 ◽  
Vol 15 (2) ◽  
pp. 106-113
Author(s):  
Manjunath P. Pai ◽  
Larry H. Danziger ◽  
Susan L. Pendland
Keyword(s):  
Amphotericin B ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Economic Consequences ◽  
Drug Selection ◽  
Testing Method ◽  
Candida Infections

Fungal infections have been increasing at an alarming rate in critically ill patients. Candida is now the fourth most common pathogen isolated from the bloodstream and is associated with significant morbidity, mortality, and economic consequences. Novel antifungals have been developed in recent years to provide alternatives to amphotericin B, which continues to be the standard therapy for most invasive fungal infections. These alternatives include lipid-based amphotericin B, ketoconazole, fluconazole, itraconazole, caspofungin, and potentially voriconazole. Optimal therapy for the various forms of candidiasis remains controversial. A standardized antifungal susceptibility testing method for Candida isolates has been developed to assist drug selection, but its clinical relevance remains to be determined. The relative susceptibility of Candida isolates can be estimated by the species. Specifically, C krusei is resistant to azoles, C glabrata may be resistant to azoles, and C lusitaniae may be resistant to amphotericin B Candida infections can affect any organ system, and the diagnosis of such infections remains difficult. The Infectious Diseases Society of America recently developed guidelines for the management of candidiasis. This review includes a brief discussion of systemically administered antifungal agents and provides a synopsis of the practice guidelines for the management of candidiasis.

scholarly journals Antifungal Susceptibility Profile of Human-Pathogenic Species of Lichtheimia

2010 ◽  
Vol 54 (7) ◽  
pp. 3058-3060 ◽  
Author(s):  
Ana Alastruey-Izquierdo ◽  
Isabel Cuesta ◽  
Grit Walther ◽  
Manuel Cuenca-Estrella ◽  
Juan Luis Rodriguez-Tudela
Keyword(s):  
Combination Therapy ◽  
Amphotericin B ◽  
Potential Role ◽  
Antifungal Agents ◽  
Active Drug ◽  
Antifungal Susceptibility ◽  
Pathogenic Species

ABSTRACT Forty-four isolates belonging to human pathogenic species of Lichtheimia were tested against nine antifungal agents by using the EUCAST methodology. No remarkable differences were found between the clinical species, although L. ramosa showed slightly higher MICs for all drugs. Amphotericin B was the most active drug. Among azole drugs, posaconazole had the best activity in vitro and voriconazole was inactive. Echinocandins showed activity for some isolates, suggesting a potential role in combination therapy.

scholarly journals Features of antifungal therapy during long-lasting infectious process: a clinical case of fungal keratitis and profile of antifungal sensitivity based on assessing biofilm formation

2021 ◽  
Vol 11 (4) ◽  
pp. 789-797
Author(s):  
R. I. Valieva ◽  
S. A. Lisovskaya ◽  
K. A. Mayanskaya ◽  
D. V. Samigullin ◽  
G. Sh. Isaeva
Keyword(s):  
Amphotericin B ◽  
Biofilm Formation ◽  
Clinical Case ◽  
Antifungal Agents ◽  
Fungal Keratitis ◽  
Laser Scanning Microscopy ◽  
Clinical Strain ◽  
Mycelial Fungi ◽  
Infectious Process ◽  
Test Culture

Among infectious diseases, opportunistic mycoses hold a special place. There has been accumulating a lot of evidence regarding the clinical and epidemiological aspects of infection caused by Fusarium spp., which global incidence rate among microbial keratitis ranges from 2 to 40% depending on the geographical location of the country. Colonizing mucous membranes, fungi can exist not only in the form of plankton, but form biofilms after surface attachment, which leads to elevated resistance to multiple antifungal agents. Here we describe a clinical case of fungal keratitis due to Fusarium solani by determining profile of the antifungal sensitivity for isolated fungal strains, by taking into account their potential for biofilm formation. We used an F. solani culture isolated from the patient as well as F. solani test culture obtained from the Russian National Collection of Microorganisms. While determining the sensitivity of fungal planktonic cultures to antifungal agents from the azole group (fluconazole, voriconazole), amphotericin B and terbinafine, it was revealed that antimycotics amphotericin B and voriconazole exerted a marked antifungal activity against clinical isolate, whereas the plankton F. solani test culture was more sensitive to all groups of antifungal agents. Due to a long-lasting progressive course of the infectious process and the high biofilm-forming ability of the clinical strain F. solani, the activity of antifungal agents on biofilm cells was modeled and examined in vitro. It was shown that regarding to the fungal biofilms, value of the minimally inhibitory concentration exceeded those for planktonic cultures by 100-fold. The mechanisms of action for antifungal agents on vital parameters of fungal cell structures were analyzed by using confocal laser scanning microscopy after staining samples with propidium iodide and acridine orange for 15 min to detect changes between intact and damaged cell surface. It was found that within the biofilm fungal cells preserved viability even after exposure to high concentrations of antifungals. In addition, despite the fungicidal drug activity at substantial concentrations acting on the biofilm cell membrane, the cell nuclei remained viable. Owing to the presence ot the mechanism of resistance in mycelial fungi shown in the study, it is necessary to take into account and investigate characteristics of biofilms in terms of drug sensitivity that will allow to optimize a choice of antimicrobial therapy.

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