In vitro sensitivity of Penicillium marneffei and Pythium insidiosum to various antifungal agents

Sekhon, Awatar S.; Padhye, A. A.; Garg, Anil Kumar

doi:10.1007/bf00158578

Cited by 47 publications

(27 citation statements)

References 16 publications

(8 reference statements)

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“…Our MIC data for itraconazole are similar to those reported by others (1,7,10), which collectively show that this fungus is extremely sensitive to this drug. Owing to the correlation of in vitro susceptibility testing data and clinical response for itraconazole, we believe that the low MICs (geometric mean titers: itraconazole, 0.04 g/ml; terbinafine, 0.09 g/ml) indicate a similar potential clinical correlation for terbinafine.…”

supporting

confidence: 90%

In Vitro Comparison of Terbinafine and Itraconazole against Penicillium marneffei

McGinnis

Nordoff

Ryder

et al. 2000

Antimicrob Agents Chemother

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We evaluated terbinafine and itraconazole against 30 isolates of Penicillium marneffei using a modification of the National Committee for Clinical Laboratory Standards broth macrodilution MIC testing protocol for yeasts. The minimal fungicidal concentration (MFC) was determined by plating 100 l from each MIC drug dilution having no growth onto Sabouraud glucose agar incubated at 30°C. The MFC was the dilution at which growth was absent at 72 h of incubation. The MICs, in micrograms per milliliter, were as follows: terbinafine, 0.03 to 1.0 (geometric mean titer, 0.09); itraconazole, 0.03 to 0.5 (geometric mean titer, 0.04). The MFCs, in micrograms per milliliter, were as follows: terbinafine, 0.03 to 8 (geometric mean titer, 2.60); itraconazole, 0.03 to 8 (geometric mean titer, 2.45). Primary fungicidal activity (MFC within 2 dilutions of MIC) was observed with terbinafine in eight isolates and with itraconazole in four isolates. The data indicate that terbinafine is active against P. marneffei in vitro and may have a previously unrealized role in the management of infections caused by this fungus.

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supporting

confidence: 90%

In Vitro Comparison of Terbinafine and Itraconazole against Penicillium marneffei

McGinnis

Nordoff

Ryder

et al. 2000

Antimicrob Agents Chemother

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“…Our MIC data for 5FC and ITC are similar to those reported by Sekhon et al (13). An in vitro study by McGinnis et al (10) demonstrated that 30 strains of P. marneffei were susceptible to ITC (MICs, 0.03 to 0.5 g/ml).…”

supporting

confidence: 89%

In Vitro Antifungal-Drug Susceptibilities of Mycelial and Yeast Forms of Penicillium marneffei Isolates in Cambodia

et al. 2006

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Penicillium marneffei infection is an important disease among human immunodeficiency virus patients inPenicillium marneffei, the only known dimorphic species in the genus Penicillium, was first isolated from an organ of a bamboo rat (Rhizomyces sinensis or Rhizomyces pruinosis) (2). Penicilliosis marneffei has been recognized with increasing frequency in Southeast Asia and Southern China (15,19,20). P. marneffei infection has become the third most common opportunistic infection in AIDS patients in Southeast Asia (17,22). Penicilliosis marneffei was first reported in Cambodia in 2002 (1). We report in vitro susceptibility test results, as determined using Etest strips, for P. marneffei isolates from human immunodeficiency virus-infected patients who presented with disseminated P. marneffei infections. We include the susceptibility test results for P. marneffei isolates from the organs of bamboo rats. Our study is the first from Cambodia to report in vitro susceptibilities of clinical and bamboo rat isolates of P. marneffei to antifungal agents.P. marneffei was isolated from 29 human immunodeficiency virus-infected patients seen at Preah Bat Norodom Sihanouk Hospital, Phnom Penh, Cambodia, from 2002 to 2004. Thirteen P. marneffei isolates were isolated from blood, 12 from skin biopsy specimens, and 4 from respiratory specimens. In all cases, only one specimen type was submitted to the laboratory. Bamboo rats (Rhizomyces pruinosus) were captured in the Mondulkiri province of Cambodia. Five isolates of P. marneffei were isolated from the lungs of 10 bamboo rats. P. marneffei was identified by the appearance of the fungal colonies on Sabouraud dextrose agar at 25°C and by microscopic examination (9).One-week-old slant cultures of the mycelial form on Sabouraud dextrose agar, grown at 25°C, were flooded with deionized distilled water (10 ml/slant), and each slant was scraped with a sterile inoculation wire loop. The suspension of mycelial fragments and conidia was transferred to a glass grinder. After the grinding, a homogenous suspension was adjusted to 1 McFarland standard (11,14). To obtain inocula of the yeast form, brain heart infusion broth (Difco) was inoculated with a fungal suspension prepared from 7-dayold slant cultures. The inoculated brain heart infusion flasks were placed on a water bath shaker (150 rpm) and incubated at 37°C for 7 days, yielding a uniform growth of yeast cells. After incubation, the broth cultures were centrifuged at 15,000 ϫ g for 20 min (4°C). After the broth was discarded, the sediment was washed three times successively with sterile deionized distilled water. The washed yeast cells were suspended in deionized distilled water and adjusted to 1 McFarland standard. Etest strips (AB Biodisk, Solna, Sweden) containing amphotericin B (AMB) (0.002 to 32 g/ml), flucytosine (5FC) (0.002 to 32 g/ml), fluconazole (FLC) (0.016 to 256 g/ml), itraconazole (ITC) (0.002 to 32 g/ ml), and ketoconazole (KTC) (0.002 to 32 g/ml) were used to determine the MICs according to the manufacturer's instructio...

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“…In humans, the infection occurs as ophthalmic, subcutaneous, and systemic forms, which are frequently associated with ␣-and ␤-thalassemia (5, 7). Pythiosis therapy, which is based on amphotericin B or azoles, has been ineffective or controversial, and the associated prognosis for human and equine pythiosis is poor (5,7,8,9,12). Therefore, surgical procedures, including amputation, are often effective, but disease reoccurrence rates are unfortunately high (7).…”

mentioning

confidence: 99%

In Vitro Activity of Terbinafine Combined with Caspofungin and Azoles against Pythium insidiosum

Cavalheiro

Maboni

Azevedo

et al. 2009

Antimicrob Agents Chemother

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In this text we evaluated the in vitro antifungal activities of terbinafine combined with caspofungin, miconazole, ketoconazole, and fluconazole against 17 Pythium insidiosum strains by using the microdilution checkerboard method. Synergistic interactions were observed with terbinafine combined with caspofungin (41.2% of the strains), fluconazole (41.2%), ketoconazole (29.4%), and miconazole (11.8%). No antagonistic effects were observed. The combination of terbinafine plus caspofungin or terbinafine plus fluconazole may have significant therapeutic potential for treatment of pythiosis.Pythiosis is a life-threatening infectious disease in humans and animals that is caused by the aquatic oomycete Pythium insidiosum (9). Horses are the most frequently infected animals, and equine pythiosis typically involves ulcerative granulomas (8). In humans, the infection occurs as ophthalmic, subcutaneous, and systemic forms, which are frequently associated with ␣-and ␤-thalassemia (5, 7). Pythiosis therapy, which is based on amphotericin B or azoles, has been ineffective or controversial, and the associated prognosis for human and equine pythiosis is poor (5,7,8,9,12). Therefore, surgical procedures, including amputation, are often effective, but disease reoccurrence rates are unfortunately high (7).Combinations of antifungal agents against pythiosis have not been thoroughly studied, and therefore, such in vitro combinatory activities against P. insidiosum require attention (1, 6).The purpose of this study was to investigate the in vitro activity of terbinafine (TRB) combined with caspofungin (CAS), miconazole (MNZ), ketoconazole, and fluconazole (FLC) against 17 strains of Pythium insidiosum isolated from animals.A total of 15 Brazilian P. insidiosum strains isolated from equines with pythiosis and two standard strains (ATCC 58637 and CBS 101555) were tested. All strains were maintained in cornmeal agar, and strain identification was confirmed by a PCR-based assay (4).The susceptibility of the P. insidiosum strains to the antifungal agents was tested by microdilution, based on protocol M38-A2 (2). The inoculum consisted of P. insidiosum zoospores obtained following zoosporogenesis. Cell numbers of zoospores were counted on a hemocytometer; zoospores were diluted in RPMI 1640 containing L-glutamine and buffered to pH 7.0 with 0.165 M MOPS (morpholinepropanesulfonic acid) to obtain a final concentration range of 2 ϫ 10 3 to 3 ϫ 10 3 zoospores/ml (10). The combinations of TRB (Novartis) plus CAS (Merck), TRB plus MNZ (Labware), TRB plus ketoconazole (Janssen), and TRB plus FLC (Pfizer) were evaluated using the checkerboard technique, according to the broth microdilution design (2,14). In the individual tests, 100 l of each drug concentration was plated in microplate wells and an equal volume of the inoculum was added to each well. In the combination tests, the antifungals were plated at a 4ϫ concentrate of 50 l of drug A plus 50 l of drug B and 100 l of the inoculum, resulting in a final 1ϫ drug concentration of each compound....

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In vitro sensitivity of Penicillium marneffei and Pythium insidiosum to various antifungal agents

Cited by 47 publications

References 16 publications

In Vitro Comparison of Terbinafine and Itraconazole against Penicillium marneffei

In Vitro Comparison of Terbinafine and Itraconazole against Penicillium marneffei

In Vitro Antifungal-Drug Susceptibilities of Mycelial and Yeast Forms of Penicillium marneffei Isolates in Cambodia

In Vitro Activity of Terbinafine Combined with Caspofungin and Azoles against Pythium insidiosum

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