Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry azole susceptibility assessment in Candida and Aspergillus species

BACKGROUND Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) allows rapid pathogen identification and potentially can be used for antifungal susceptibility testing (AFST). OBJECTIVES We evaluated the performance of the MALDI-TOF MS in assessing azole susceptibility, with reduced incubation time, by comparing the results with the reference method Broth Microdilution. METHODS Resistant and susceptible strains of Candida (n = 15) were evaluated against fluconazole and Aspergillus (n = 15) against itraconazole and voriconazole. Strains were exposed to serial dilutions of the antifungals for 15 h. Microorganisms' protein spectra against all drug concentrations were acquired and used to generate a composite correlation index (CCI) matrix. The comparison of autocorrelations and cross-correlations between spectra facilitated by CCI was used as a similarity parameter between them, enabling the inference of a minimum profile change concentration breakpoint. Results obtained with the different AFST methods were then compared. FINDINGS The overall agreement between methods was 91.11%. Full agreement (100%) was reached for Aspergillus against voriconazole and Candida against fluconazole, and 73.33% of agreement was obtained for Aspergillus against itraconazole. MAIN CONCLUSIONS This study demonstrates MALDI-TOF MS' potential as a reliable and faster alternative for AFST. More studies are necessary for method optimisation and standardisation for clinical routine application.

Evaluation of antifungal susceptibility and clinical characteristics in fungal keratitis in a tertiary care center in North India

Purpose: To study the antifungal susceptibility of common corneal pathogenic fungi to antifungal agents in the North Indian population. Methods: Prospective study of the antifungal sensitivity testing (natamycin, amphotericin B, voriconazole, itraconazole, fluconazole, posaconazole, caspofungin, micafungin) of fungal isolates from 50 cases of culture positive fungal keratitis by using E test method. Details noted included demographic data, visual acuity, clinical details, grade of keratitis, healing time, and success in medical management. Results: Of 50 patients with fungal keratitis (mean age: 40.28 ± 16.77 years), 12 eyes healed within 3 weeks, 14 had a delayed healing response, and 24 had chronic keratitis. Among the 15 cases of Fusarium isolates, 93.3% were sensitive to natamycin, while 40% to amphotericin B; 66.6% to voriconazole, 13.4% to itraconazole and fluconazole each. 80% of Fusarium cases (n = 12) showed susceptibility to posaconazole. Among Aspergillus flavus isolates, 53.4% (n = 8) were sensitive to natamycin, with only 40% (n = 7) showing sensitivity to amphotericin B and good susceptibility to azoles. MIC against susceptible Fusarium spp. for natamycin was 3–16 ?g/mL, amphotericin B: 1–8 ?g/mL, voriconazole: 0.5–1.5 ?g/ mL, itraconazole: 0.5–12 ?g/mL, posaconazole: 0.094–1.5 ?g/mL. MIC against Aspergillus flavus was natamycin: 8–32 ?g/mL, amphotericin B: 0.5–16 ?g/mL, voriconazole: 0.025–4 ?g/mL, itraconazole: 0.125–8 ?g/mL, posaconazole: 0.047–0.25 ?g/mL; against Aspergillus niger isolates, to natamycin was 6 ?g/mL (n=1), amphotericin B 8–12 ?g/mL (n = 3), voriconazole: 0.125–0.19 ?g/mL (n = 3), itraconazole: 0.38–0.75 ?g/mL, posaconazole: 0.064–0.19 ?g/mL and against Aspergillus fumigatus (n = 1), was natamycin4 ?g/ mL, amphotericin B ? 8 ?g/mL, voriconazole 0.25 ?g/mL, itraconazole 1 ?g/mL, and posaconazole 0.19 ?g/mL. MIC against susceptible Acremonium spp. for natamycin was 1.5–16 ?g/mL, amphotericin B: 0.5–8 ?g/mL, voriconazole: 0.19–3 ?g/mL, itraconazole: 0.125 ?g/mL, posaconazole: 0.125–0.5 ?g/mL and against susceptible Curvularia was natamycin 0.75–4 ?g/mL, amphotericin B 0.5–1 ?g/mL, voriconazole 0.125–0.19 ?g/mL, itraconazole 0.047–0.094 ?g/mL, posaconazole 0.047–0.094 ?g/mL. MIC against Mucor spp.+ Rhizopus spp. (n = 1) was natamycin: 8 ?g/mL, amphotericin B: 0.75 ?g/mL, posaconazole: 1.5 ?g/ mL. MIC against of Alternaria (n = 1) was voriconazole: 0.19 ?g/mL, posaconazole: 0.094 ?g/mL. MIC against Penicillium (n=1) was natamycin: 8 ?g/mL, voriconazole: 0.25 ?g/mL, itraconazole: 0.5 ?g/mL, and Posaconazole: 0.125 ?g/mL. Conclusion: Our observations highlight the variations in susceptibility to antifungal agents. Posaconazole seems to be effective with low MIC against common corneal pathogenic fungal isolates

Schizophyllum commune maxillary sinusitis in an immunocompromised patient: A case report

Schizophyllum commune is a basidiomycotic fungus that grows ubiquitously on trees and rotting wood. Human infections caused by it are of diverse presentation but are very rare. We present a case of sinusitis caused by S. commune in a 58-year-old female patient with post-COVID-19 infection along with a history of allergic rhinitis and diabetes mellitus type 2. Computed tomography scan findings established the clinical diagnosis of fungal maxillary sinusitis which was confirmed with culture report and polymerase chain reaction followed by sequencing. The patient underwent functional endoscopic sinus surgery. She was treated empirically with itraconazole after surgical excision

Identification of Candida Species from Clinical Isolates and Their Antifungal Susceptibility Pattern.

With increasing use of antibacterial and cytotoxic drugs, lethal invasive Candidiasis is on the rise, with almost half of the cases being caused by non albicans Candida species (NAC). Frequent use of azoles for empirical therapy has also led to their increased resistance. We wanted to characterise Candida species isolated from various clinical specimens and assess their susceptibility pattern to Fluconazole and Voriconazole.METHODSA total of 100 consecutive Candida species isolated from various clinical specimens in our institute from January 2016 to December 2016 were included in the study. Standard yeast identification protocol and CHROM agar were used for speciation and their antifungal susceptibility pattern was found by disc diffusion method.RESULTSOut of the 100 isolates, C. tropicalis was the predominant isolate (47%), followed by C. albicans (31%), C. parapsilosis (16%) and C. krusei (6%). Females (57%) were more affected and maximum number of patients was above 60 years (24%). Diabetes mellitus (21%) was the major predisposing factor for Candida, followed by broad spectrum antibiotic therapy (14%). Isolates were more susceptible to Voriconazole (99%) than Fluconazole (87%). NAC spp. showed more resistance to Fluconazole (17.4%) than C. albicans (3.3%). Only one isolate of C. krusei (16.6%) showed resistance to Voriconazole.CONCLUSIONSDue to the increasing incidence of azole resistant NAC spp., the species level identification of Candida species, along with their anti-fungal susceptibility patterns can help the clinicians in formulating a treatment protocol and can help in decreasing the mortality and morbidity.

An etiological and antifungal profile of candidemia in children

Background: Candidemia causing increased mortality rates and emergence of antifungal drug resistance needs an urgent intervention to salvage immunocompromised and severely ill patients. This study aimed to isolate and identify Candida species and evaluate their antifungal susceptibility profile from blood stream infections in children.Methods: Fungal cultures from blood recovered positive for yeasts were subcultured on Sabouraud dextrose agar. Suspected purified colonies of Candida were confirmed and identified upto species level by both conventional and automated techniques. Antifungal susceptibility testing of isolates was evaluated using agar based E-test method for fluconazole, voriconazole and caspofungin on Mueller-Hinton agar supplemented with 2% glucose.Results: Total of 43 isolates of Candida species were recovered from blood samples. Non albicans Candida species accounted for 88.30% of cases; whereas 11.60% of cases were caused by C. albicans, C. tropicalis (39%) was the most frequent isolate recovered in candidemia patients followed by C. parapsilosis (18%), C. albicans (12%), C. glabrata (12%), C. kefyr (9%), C. pelliculosa (5%), and C. krusei (5%). Antifungal susceptibility results revealed Caspofungin demonstrated good activity against all Candida spp. C. parapsilosis followed by C. tropicalis and C. glabrata demonstrated high resistance to fluconazole. For voriconazole, maximum resistance was shown by C. tropicalis as compared to others.Conclusions: Candidemia is a threatening prognostic sign in children and an important entity in our hospital. Identification of Candidaspecies and antifungal sensitivity testing is a must to select a suitable and effective antifungal therapy to abrogate the emerging resistance to antifungals.

Antifungal susceptibility testing for dermatophytes isolated from clinical samples by microbroth dilution method

Background: The cases of dermatophytoses have increased over the past few decades. Dermatophytoses affect the outer layers of skin, nails and hairs without tissue invasion. These infections are mostly not dangerous but, are important as public health problem particularly in the immunocompromised. The increased use of antifungal drugs for prolonged periods may lead to acquired antifungal resistance among previously susceptible strains. With this background present study was conducted to know the susceptibility pattern of dermatophytes.Methods: A total 35 isolates of dermatophytes isolated from clinically suspected cases of dermatophytoses were examined. Broth microdilution method M38-A2 approved protocol of CLSI (2008) for filamentous fungi was followed for determining the susceptibility of dermatophyte species to antifungal agents- itraconaole, fluconazole and ketoconazole.Results: Itraconazole minimum inhibitory concentrations (MIC) varied from 0.0156 to 1 µg/ml for all dermatophytes. T. rubrum species showed higher MIC range for Ketoconazole than T. mentagrophytes and T. tonsurans. Fluconazole had poor susceptibility for all dermatophytes by having higher MIC values.Conclusions: The MIC values observed in present study will help clinician to select an appropriate antifungal agent with minimal side effects. The data from present study can be useful as reference for future studies covering large no. of isolates and more drugs.

Speciation and antifungal susceptibility pattern of Candida isolates from vulvovaginitis patients attending a tertiary care hospital in South India

Background: Vulvovaginal candidiasis is a global issue of concern due to its association with economic costs, sexually transmitted infections, and ascending genital tract infection leading to several complications in both pregnant as well as non-pregnant women. It is second to bacterial vaginosis affecting approximately 50–72% of women of reproductive age group. Resistance to antifungal agents has increased during the last decade. Thus, identification of Candida up to species level and its antifungal susceptibility testing is essential in the management of Candidal infections. Aim: To determine the prevalence of various Candida species among vaginal candidiasis and to determine the antifungal susceptibility pattern of the isolates. Materials and methods: A total of 56 Candida species were isolated from 200 clinical diagnosed cases of vaginitis over 6 months period. Growth on Sabouraud dextrose agar were evaluated according to standard protocol and further processed for Candida speciation on CHROM agar. Antifungal susceptibility testing was performed using the Etest method as recommended by Clinical and Laboratory Standards Institute (CLSI) M27-A3 document. Results: Out of 200 vaginitis patients, 56 were positive for Candida species. All the isolates were speciated comprising four species – C. albicans 24 (42.8%), C. krusei 20 (35.7%), C. tropicalis 7 (12.5%), and C. glabrata 5 (8.9%). Antifungal susceptibility testing result of all Candida isolates were Lavanya V, Pavani P, Kailasanatha Reddy B. Speciation and antifungal susceptibility pattern of Candida isolates from vulvovaginitis patients attending a tertiary care hospital in South India. IAIM, 2019; 6(2): 62-68. Page 63 100% susceptible to amphotericin B, nystatin and voiconazole. C. krusei and C.glabrata isolates were showed 100% resistance to fluconazole and ketoconazole respectively. Conclusion: In the present study, C. albicans was most common species followed by C. krusei. Presumptive identification followed by confirmation of Candida species helps to initiate early appropriate antifungal treatment. The relatively higher resistance shown by Non-abicans Candida species to commonly prescribed antifungals (fluconazole and ketoconazole) emphasizes the need for routine antifungal susceptibility testing of all Candida isolates

Rapid identification and antifungal susceptibility testing of filamentous fungi / 临床检验杂志

Objective To evaluate the application of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technology in the identification of filamentous fungi,and analyze the susceptibility of filamentous fungi to commonly used antibiotics.Methods A total of 100 strains of filamentous fungi were collected and identified rapidly by MALDI-TOF MS.The obtained results were compared with those from microscopic examination.The susceptibility of filamentous fungi was detected by the Etest method.Results Among 100 strains of filamentous fungi identified by MALDI-TOF MS,61 reached to the species level(score≥2.000),36 to the genus level(score between 1.700 and 1.999),and 3 failed to be identified (score ＜ 1.700).There was inconsistent results for one strain of filamentous fungi between MALDI-TOF MS and microscopic examination.The MIC90 of amphotericin B against Epidermophytonfloccosum was 0.19 μg/mL,while that against Aspergillus flavus was above 32 μg/mL.The MIC90 of itraconazole against Trichophyton tonsurans,Microsporum canis and Epidermophytonfloccosum were all below 0.38 μg/mL,while that against Aspergillus niger was above 32 μg/mL.The MIC90 of fluconazol were above 256 μg/mL for most of strains.The MIC90 of voriconazole and caspofungin against Aspergillus fumigatus,Aspergillus flavus,Aspergillus niger,Trichophyton rubrum,Trichophyton tonsurans and Microsporum canis were ≤0.38 μg/mL and ≤ 1 μg/mL,respectively.Conclusion The MALDI-TOF MS technology may be used to identify the filamentous fungi isolated from clinical specimens quickly,accurately and high-throughput.Voriconazole and caspofungin have effective anti-filamentous fungi activity.

The epidemiology of cryptococcosis and the characterization of Cryptococcus neoformans isolated in a Brazilian University Hospital

ABSTRACT Cryptococcosis, a systemic disease caused by the fungus Cryptococcus neoformans/ Cryptococcus gattii is more severe in immunocompromised individuals. This study aimed to analyze the epidemiology of the disease, the molecular characteristics and the antifungal susceptibility of C. neoformans isolated from patients treated in a Brazilian university hospital. This retrospective study was conducted in the Clinical Hospital, Federal University of Uberlândia, and evaluated cases of cryptococcosis and strains of C. neoformans isolated from 2004 to 2013. We evaluated 41 patients, 85% of whom were diagnosed with AIDS. The fungus was isolated from the cerebrospinal fluid (CSF) of 21 patients (51%); 19.5% had fungemia and in 24% the agent was isolated from the CSF and blood, concurrently. Meningoencephalitis was the most frequent (75%) manifestation of infection. Despite adequate treatment, the mortality of the disease was 58.5%. Most isolates (97.5%) presented the VNI genotype (serotype A, var. grubii) and one isolate was genotyped as C. gattii (VGI); all the isolates were determined as mating type MATa and showed susceptibility to the tested antifungals (fluconazole, voriconazole, amphotericin B and 5-flucytosine). Although AIDS detection rates remain stable, opportunistic infections such as cryptococcosis remain as major causes of morbidity and mortality in these patients.

Species distribution & antifungal susceptibility pattern of oropharyngeal Candida isolates from human immunodeficiency virus infected individuals.

Background & objectives: The changing spectrum of Candida species in causation of oropharyngeal candidiasis and their antifungal susceptibility pattern among the HIV infected individuals has made the identification to species level mandatory and detection of drug resistance necessary for patient care. The present study was carried out to determine the species distribution and antifungal susceptibility profile of oral Candida isolates colonizing or infecting both HIV seropositive and seronegative individuals. Methods: A case-control study was conducted including 141 consecutive, non-repeat HIV-seropositive individuals and an equal number of sex and age matched HIV-seronegative control. Speciation of the oropharyngeal Candida isolates was done using standard yeast identification protocol. Antifungal susceptibility testing was done by the disk-diffusion method as well as by Fungitest method. Results: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candida albicans (n=47, 77.0%), C. dubliniensis (n=9, 14.7%), C. parapsilosis (n=2, 3.2%), C. glabrata (n=2, 3.2%), and C. famata (n=1, 1.6%). Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control) group. Antifungal susceptibility testing revealed (n=6, 9.3%) C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method. Interpretation & conclusions: C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country.

Species Identification And Antifungal Susceptibility Pattern Of Candida Isolates From Oropharyngeal Lesions Of HIV Infected Patients..

Background &Objective: Oropharyngeal candidiasis (OPC) is a common feature associated with HIV infection. Over the past decade, reports have documented a shift away from C. albicans as a major cause of infection to non albicans Candida (NAC) species. Several NAC spp are inherently resistant to commonly used antifungal drugs. The objective of the present study was to investigate the distribution pattern of Candida spp. from HIV infected patients with OPC and evaluate its antifungal susceptibility pattern. Methods: A total of 192 HIV infected patients with oropharyngeal lesions (OPL) suggestive of candidiasis and 60 non HIV infected healthy individuals presenting without any OPL were included in the study.Swabs collected from the site of lesions were used for the demonstration and isolation of Candida. Speciation of Candida isolates was done and antifungal susceptibility testing was performed by the disc diffusion method. Results: Out of 192 HIV-infected patients with OPL, 179(93.2%) showed growth of Candida. Isolation of NAC species was higher than C. albicans. Azole resistance was more in NAC species as compared to C. albicans.Conclusions: NAC species has emerged as an important cause of OPC in HIV infected patients. The increased isolation rates of NAC species and a gradual shift in the antifungal susceptibility profile underlines the need of early and accurate diagnosis of infecting Candida spp along with antifungal susceptibility testing for selecting the most appropriate antifungal agent for therapy.

Susceptibilidad in vitro de candida spp: aisladas de la cavidad oral de pacientes VIH/Sida a itraconazol, clotrimazol y ketoconazol / In vitro susceptibility of candida ssp: isolated fromthe oral cavity of HIV/AIDS patientes to itraconazole, clotrimazole and ketoconazole

La candidiasis orofaríngea (COF) permanece como una de las principales infecciones oportunistas en pacientes infectados con el virus de la inmunodeficiencia humana (VIH) y con el síndrome de inmunodeficiencia adquirida (sida), y aunque su incidencia ha disminuido con la introducción de la terapia antirretroviral de alta eficacia, continúa siendo una afección característica en estos pacientes. En el presente trabajo se realizó un estudio de susceptibilidad in vitro mediante la metodología del CLSI, frente a itraconazol, ketoconazol y clotrimazol de 144 aislamientos clínicos de Candida, aisladas de la cavidad oral de pacientes infectados con el VIH/sida con cuadros clínicos de COF. La identificación de los aislamientos demostró que más del 90% pertenecían a Candida albicans. Al determinar el patrón general de susceptibilidad frente a los azoles estudiados mediante el método de microdilución en caldo del documento M27-A2 del Clinical and Laboratory Standard Institute, C. albicans exhibió valores de concentración mínima inhibitoria (CMI) en un rango de 0,01 a 8µg/mL para el itraconazol y el ketoconazol y de 0,01 a 2 g/mL para el clotrimazol. Sólo el 2,1 % de los aislamientos mostró franca resistencia frente al itraconazol, en tanto que el 3,5 % quedó clasificado dentro de la categoría “susceptible dosis-dependiente” para este triazol. La mayoría de los aislamientos de C. albicans mostraron valores de CMI frente al ketoconazol y al clotrimazol menores a 0.06 g/mL, siendo de un 96,9% (129 aislamientos) y de un 97,7% (129 aislamientos), respectivamente. El clotrimazol tuvo una mejor actividadin vitro comparado con los restantes azoles frente a los aislamientos estudiados. Candida spp. Mostró una elevada sensibilidad in vitro a los azoles estudiados. Se hace necesario continuar realizando estudios epidemiológicos para determinar los patrones de susceptibilidad y tasas de resistencias frente a los agentes...

The oropharyngeal candidiasis (OFC) remains as one of the principal opportunistic infections in patients infected with the human immunodeficiency virus (HIV) and with the acquired immunodeficiency syndrome (aids), and although his incidence has declined with the introduction of the highly active anti-retroviral therapy (HAART), remains as a typical complaint in these patients. A study of antifungal in vitro susceptibility testing, following the CLSI methodology, was realized against itraconazole, ketoconazole and clotrimazole of 144 clinical isolations of Candida, isolated from the oral cavity of patients infected with HIV/aids, with clinical pictures of OFC. The isolation’s identification, demonstrated that more than 90% belonged to Candida albicans. The determination of the general pattern of susceptibility, following the document M27-A2 of the Clinical and Laboratory Standard Institute, against to the studied azoles by means of the method of microdilution in liquid medium, show that the majority of C. albicans isolates showed values of MIC against ketoconazole and clotrimazole lower than 0.06 g/mL, representing a 96,9% (129 isolations) and a 97,7% (129 isolations), respectively. C. albicans exhibited the widest range of minimal inhibitory concentration (MIC). Only 2.1% of the isolations showed resistance against to itraconazole, while 3.5 % remained classified in the category “sensible dose - dependent” for this triazole. The majority of the strains showed values of MIC against ketoconazole and clotrimazole below 0.06 g/mL. The clotrimazole had a better in vitro activity compared with the remaining azoles opposite to the isolations. Candida spp. showed a high in vitro sensibility to the azoles studied. It becomes necessary the maintenance of epidemiologic studies for the determination of susceptibility patterns and of resistances rates against to the antifungal agents

Vulvovaginal candidiasis in Mato Grosso, Brazil: pregnancy status, causative species and drugs tests

Causative agent in majority of VVC is Candida albicans, but infection due to non-C. albicans is common. Use of empiric antifungal therapy in Brazil due to syndromic management of vulvovaginitis could act as risk factor for increase resistance among VVC causative agents. From Mato Grosso patients, 160 with culture-proved among 404 women who had clinical symptoms of VVC, were enrolled in this study. 70 non-pregnant women and 90 pregnant women were included. Candida albicans was the most prevalent, representing 72.9 percent in the non-pregnant group and 92.3 percent in the pregnant group. Differences in species distribution were noted between the two groups, being C. parapsilosis the second more prevalent species among non-pregnant women. Susceptibility testing revealed high susceptibility to fluconazole (except for C. krusei), itraconazole, ketoconazole, and amphotericin B regardless the species (C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, C. krusei) analyzed.

Detection and antifungal susceptibility testing of oral Candida dubliniensis from human immunodeficiency virus-infected patients.

Context: Candida dubliniensis, an opportunistic yeast that has been implicated in oropharyngeal candidiasis (OPC) in patients infected with Human Immunodeficiency Virus (HIV) may be under-reported due to its similarity with Candida albicans. Resistance to Fluconazole is often seen in C. dubliniensis isolates from clinical specimens. Aims: To know the prevalence of C. dubliniensis in OPC in patients infected with HIV and their antifungal susceptibility pattern. Settings and Design: One hundred and thirty-two HIV seropositive individuals and 50 healthy controls were included in the study. Materials and Methods: Two oral swabs were collected from the site of the lesion from 132 HIV-infected patients. Oral rinse was obtained from 50 healthy controls. Samples were inoculated on Sabouraud's dextrose agar (SDA) medium and on HiCrome Candida Differential Agar (CHROM agar) medium. Isolates were speciated by standard tests. Dark green-colored, germ tube positive isolates, which failed to grow at 420C and negative for xylose assimilation were identified as C. dubliniensis. Antifungal susceptibility test was performed by Macro broth dilution technique (National Committee for Clinical Laboratory Standards guidelines). Results and Conclusions: From 132 patients, 22 (16.3%) C. dubliniensis were isolated; samples from healthy controls did not reveal their presence. Antifungal susceptibility test showed higher resistance among C. dubliniensis isolates to azoles compared to C. albicans. Five (22.7%) isolates of C. dubliniensis were resistant to Fluconazole followed by four (18.2%) to Ketoconazole. This study emphasizes the importance of identification and antifungal susceptibility testing of C. dubliniensis in HIV-infected patients.

In vitro susceptibility testing of dermatophytes isolated from pediatric cases in Nigeria against five antifungals

The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 µg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.

Atividades antifúngicas de itraconazole, ketoconazole, fluconazole, terbinafine e griseofulvina foram testadas por métodos de microdiluição em caldo contra 71 isolados de dermatófitos de crianças nigerianas. A maioria das drogas foi muito ativa contra todos os dermatófitos e o MIC 90 variou de 0,03 a 8,0 µg/mL. Estes parecem ser os primeiros dados documentados sobre os testes de susceptibilidade antifúngica de isolados de dermatófitos de crianças nigerianas.

Antifungal Drug Susceptibility / 한양의대학술지

In the past two decades standardized in vitro antifungal susceptibility testing has been developed in responsive to increasing invasive fungal infections. Until now, antifungal susceptibility testing is not considered as a routine testing procedure in many laboratories. However, cumulative antifungal susceptibility data of fungi show that, because of the fungal organisms' different susceptibilities to antifungal agents, knowledge of the infecting fungal species is highly predictive of likely susceptibility and can be used as a guide to therapy. Recently, routine use of fluconazole susceptibility testing for Candida species is becoming recognized as a useful aid in optimizing treatment of candidiasis. This testing may be particularly useful in patients with recurrent mucosal candidiasis, and candidemia or invasive candidiasis who have been previously treated with azole antifungals, those whose infections are not responding to treatment, and those with infections caused by non-albicans species of Candida. As several new antifungal drugs have been or will be licensed in the next few years, it is very important for the clinicians to choose antifungal agents appropriately, while considering changing epidemiology and susceptibility trends.

In Vitro Susceptibilities to Caspofungin and Micafungin of Clinical Isolates of Candida Species / 대한진단검사의학회지

BACKGROUND: Caspofungin and micafungin are echinochandins with potent activities against Candida species. However, in vitro susceptibility to these agents of clinical Candida isolates in Korea has not been fully surveyed. We determined minimum inhibitory concentrations (MICs) of caspofungin and micafungin against clinical isolates of Candida species. METHODS: A total of 107 blood isolates of Candida species (24 C. albicans, 25 C. tropicalis, 24 C. glabrata, 20 C. parapsilosis, 8 C. krusei, and 6 other Candida species) were tested by using the National Committee for Clinical Laboratory Standards M27-A2 broth microdilution methods. The in vitro antifungal activities and spectrum of caspofungin and micafungin were compared with those of amphotericin B, fluconazole, and itraconazole. RESULTS: Caspofungin and micafungin exhibited a broad-spectrum activity against Candida species: caspofungin MIC ranged from 0.125 to 1 microgram/mL and micafungin MIC from < or =0.03 to 1 microgram/mL. C. albicans, C. tropicalis and C. glabrata showed high susceptibility to caspofungin (MIC90, 0.25 to 0.5 microgram/mL) and micafungin (MIC90 , < or =0.03 microgram/mL), whereas C. parapsilosis was less susceptible to both echinocandins (MIC90, 1 microgram/mL). The MIC50 for caspofungin, micafungin, amphotericin B, fluconazole, and itraconazole were 0.25, < or =0.03, 0.5, 1, and 0.125 microgram/mL, respectively. Caspofungin MIC50 of C. glabrata and C. krusei isolates with decreased susceptibility to azoles were 0.25 and 0.5 microgram/mL, respectively, and micafungin MIC50 were < or =0.03 and 0.125 microgram/mL, respectively. CONCLUSIONS: These data showed an excellent in vitro activity of caspofungin and micafungin against clinical strains of Candida species, including isolates with reduced susceptibility to azoles.

Evaluation of Spectrophotometric Broth Microdilution Method to Determine the Fluconazole MIC of the Candida Species / 대한진단검사의학회지

BACKGROUND: Although the broth microdilution method has been recently established for antifungal susceptibility testing of the Candida species, there is still an argue in the interpretation of the trailing endpoint. We evaluated the spectrophotometric broth microdilution method (SBM) to determine the fluconazole MICs from five different Candida species. METHODS: A total of 252 clinical isolates of five Candida species (144 C. albicans, 42 C. tropicalis, 32 C. glabrata, 28 C. parapsilosis, and 6 C. krusei) were tested for fluconazole susceptibility with the broth microdilution method. The MICs were spectrophotometrically determined at 80% (Spec-80%) and 50% (Spec-50%) decrease in absorbance as compared with growth control, respectively. The results were compared with the fluconazole MICs tested by the National Committee for the Clinical Laboratory Standards (NCCLS) macrodilution method. RESULTS: When MICs were obtained by Spec-80%, the agreements of SBM and the NCCLS macro dilution method within two doubling dilutions were 92.4% (220/238) at 24 h and 78.6% (198/252) at 48 h for all Candida species. Using the Spec-50%, those were increased to 97.9% (233/238) at 24 h and 98.8% (249/252) at 48 h (P<0.01). Especially, for C. albicans and C. tropicalis, the agreement of the Spec-50% was significantly higher than those of the Spec-80% at 48 h; 97.9% vs. 75.0%, for C. albicans (P<0.01), and 100% vs. 57.1%, for C. tropicalis (P<0.01). CONCLUSIONS: These data suggest that the SBM using Spec-50% can provide a more precise and objective mean for fluconazole susceptibility testing, especially for C. albicans and C. tropicalis.

Antifungal Susceptibilities to Fulconazole and Itraconazole for Candida Species Recovered from Blood Cultures over a 5-Year Period / 감염

BACKGROUND: Fluconazole and itraconazole, the azole-derivative antifungal agents, have been commonly used for the treatment of candidiasis. We studied the comparative activities of fluconazole and itraconazole against isolates of Candida species recovered from blood cultures in Chonnam National University Hospital between 1994 and 1998. METHODS: One hundred twenty-four bloodstream isolates of Candida species (32 C. albicans, 36 C. parapsilosis, 19 C. tropicalis, 12 C. glabrata, 10 C. pelliculosa, 7 C. guilliermondii, 5 C. lipolytica, and 3 others) from 124 patients were tested. Minimal inhibitory concentrations (MICs) of fluconazole (0.12~64microgram/mL) and itraconazole (0.03~16 microgram/mL) for each isolate were determined by the NCCLS broth macrodilution method. RESULTS: Fluconazole MICs were >64 microgram/mL for 4.8% (6/124) of the isolates and 16~32 microgram/mL for the 8.9% (11/124) isolates. Itraconazole MICs were >1 microgram/mL for 16% (16/124) and 0.25~0.5 microgram/mL for 21.0% (26/124) of the isolates. Candida species for which the fluconazole MICs were higher, were in general more resistant to itraconazole (P64 microgram/mL) or itraconazole (> 1 microgram/mL) was observed in 4.5% (2/44) of isolates obtained from 1994 to 1996, and increased to 17.5% (14/80) of isolates recovered in 1997 to 1998 (P<0.05). CONCLUSION: This data showed that itraconazole MICs were proportionally higher for Candida isolates with high fluconazole MICs, and Candida species with fluconazole or itraconazole resistance increased in the latter two years, although MICs of fluconazole and itraconazole for each species did not change during the 5-year span.

Differentiation of Varieties and Susceptibility Testing for Two Strains of Cryptococcus neoformans / 대한임상병리학회지

Typing of cryptococcal varieties and antifungal susceptibility testing were performed on two strains which were isolated from a nonimmunosuppressed host with cryptococcal meningitis and another from a patient with systemic cryptococcosis with underlying liver cirrhosis. Both varieties of clinical isolates were identified by the use of the glycin-cycloheximide-bromothymol blue agar medium as Cryptococcus neoformans variety neoformans. For the two isolates of Cryptococcus neoformans, the minimal inhibitory concentrations (MIC) of amphotericin B were 0.25 g/mL and the MICs of fluconazole were 8 g/mL.