1
|
Franconi I, Lupetti A. In Vitro Susceptibility Tests in the Context of Antifungal Resistance: Beyond Minimum Inhibitory Concentration in Candida spp. J Fungi (Basel) 2023; 9:1188. [PMID: 38132789 PMCID: PMC10744879 DOI: 10.3390/jof9121188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
Antimicrobial resistance is a matter of rising concern, especially in fungal diseases. Multiple reports all over the world are highlighting a worrisome increase in azole- and echinocandin-resistance among fungal pathogens, especially in Candida species, as reported in the recently published fungal pathogens priority list made by WHO. Despite continuous efforts and advances in infection control, development of new antifungal molecules, and research on molecular mechanisms of antifungal resistance made by the scientific community, trends in invasive fungal diseases and associated antifungal resistance are on the rise, hindering therapeutic options and clinical cures. In this context, in vitro susceptibility testing aimed at evaluating minimum inhibitory concentrations, is still a milestone in the management of fungal diseases. However, such testing is not the only type at a microbiologist's disposal. There are other adjunctive in vitro tests aimed at evaluating fungicidal activity of antifungal molecules and also exploring tolerance to antifungals. This plethora of in vitro tests are still left behind and performed only for research purposes, but their role in the context of invasive fungal diseases associated with antifungal resistance might add resourceful information to the clinical management of patients. The aim of this review was therefore to revise and explore all other in vitro tests that could be potentially implemented in current clinical practice in resistant and difficult-to-treat cases.
Collapse
Affiliation(s)
- Iacopo Franconi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy;
- Mycology Unit, Pisa University Hospital, 56126 Pisa, Italy
| | - Antonella Lupetti
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy;
- Mycology Unit, Pisa University Hospital, 56126 Pisa, Italy
| |
Collapse
|
2
|
Adnan A, Borman AM, Tóth Z, Forgács L, Kovács R, Balázsi D, Balázs B, Udvarhelyi G, Kardos G, Majoros L. In Vitro Killing Activities of Anidulafungin and Micafungin with and without Nikkomycin Z against Four Candida auris Clades. Pharmaceutics 2023; 15:pharmaceutics15051365. [PMID: 37242607 DOI: 10.3390/pharmaceutics15051365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/05/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Candida auris is a multidrug-resistant pathogen against which echinocandins are the drug of choice. However, information on how the chitin synthase inhibitor nikkomycin Z influences the killing activities of echinocandins against C. auris is currently lacking. We determined the killing activities of anidulafungin and micafungin (0.25, 1, 8, 16 and 32 mg/L each) with and without nikkomycin Z (8 mg/L) against 15 isolates representing four C. auris clades (South Asian n = 5; East Asian n = 3; South African n = 3; South American n = 4, two of which were of environmental origin). Two and one isolates from the South Asian clade harbored mutations in the hot-spot 1 (S639Y and S639P) and 2 (R1354H) regions of the FKS1 gene, respectively. The anidulafungin, micafungin and nikkomycin Z MIC ranges were 0.015-4, 0.03-4 and 2->16 mg/L, respectively. Anidulafungin and micafungin alone exerted weak fungistatic activity against wild-type isolates and the isolate with a mutation in the hot-spot 2 region of FKS1 but was ineffective against the isolates with a mutation in the hot-spot 1 region. The nikkomycin Z killing curves were always similar to their respective controls. Twenty-two of sixty (36.7%) anidulafungin plus nikkomycin Z and twenty-four of sixty (40%) micafungin plus nikkomycin Z combinations produced at least 100-fold decreases in the CFUs (synergy), with a 41.7% and 20% fungicidal effect, respectively, against wild-type isolates. Antagonism was never observed. Similar results were found with the isolate with a mutation in hot-spot 2 of FKS1, but the combinations were ineffective against the two isolates with prominent mutations in hot-spot 1 of FKS1. The simultaneous inhibition of β-1,3 glucan and chitin synthases in wild-type C. auris isolates produced significantly greater killing rates than either drug alone. Further studies are warranted to verify the clinical efficacy of echinocandin plus nikkomycin Z combinations against echinocandin susceptible C. auris isolates.
Collapse
Affiliation(s)
- Awid Adnan
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Andrew M Borman
- UK National Mycology Reference Laboratory, UK Health Security Agency, Science Quarter, Southmead Hospital, Bristol BS10 5NB, UK
- Medical Research Council Centre for Medical Mycology (MRC CMM), University of Exeter, Exeter EX4 4QD, UK
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Lajos Forgács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dávid Balázsi
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Bence Balázs
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Gergely Udvarhelyi
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Gábor Kardos
- Department of Metagenomics, University of Debrecen, 4032 Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| |
Collapse
|
3
|
Tóth Z, Forgács L, Kardos T, Kovács R, Locke JB, Kardos G, Nagy F, Borman AM, Adnan A, Majoros L. Relative Frequency of Paradoxical Growth and Trailing Effect with Caspofungin, Micafungin, Anidulafungin, and the Novel Echinocandin Rezafungin against Candida Species. J Fungi (Basel) 2020; 6:jof6030136. [PMID: 32824464 PMCID: PMC7560028 DOI: 10.3390/jof6030136] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/07/2020] [Accepted: 08/13/2020] [Indexed: 01/05/2023] Open
Abstract
Rezafungin is a next-generation echinocandin that has favorable pharmacokinetic properties. We compared the occurrence of paradoxical growth (PG) and trailing effect (TE) characteristics to echinocadins with rezafungin, caspofungin, micafungin and anidulafungin using 365 clinical Candida isolates belonging to 13 species. MICs were determined by BMD method according to CLSI (M27 Ed4). Disconnected growth (PG plus TE) was most frequent with caspofungin (49.6%), followed by anidulafungin (33.7%), micafungin (25.7%), while it was least frequent with rezafungin (16.9%). PG was relatively common in the case of caspofungin (30.1%) but was rare in the case of rezafungin (3.0%). C. tropicalis, C. albicans, C. orthopsilosis and C. inconspicua exhibited PG most frequently with caspofungin, micafungin or anidulafungin. PG never occurred in the case of C. krusei isolates. Against C. tropicalis and C. albicans, echinocandins frequently showed PG after 24 h followed by TE after 48 h. All four echinocandins exhibited TE for the majority of C. auris and C. dubliniensis isolates. Disconnected growth was common among Candida species and was echinocandin- and species-dependent. In contrast to earlier echinocandins, PG was infrequently found with rezafungin.
Collapse
Affiliation(s)
- Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Lajos Forgács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Kardos
- Department of Pulmonology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
- Faculty of Pharmacy, University of Debrecen, 4032 Debrecen, Hungary
| | - Jeffrey B. Locke
- Cidara Therapeutics, Inc., 6310 Nancy Ridge Dr., Suite 101, San Diego, CA 92121, USA;
| | - Gábor Kardos
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
| | - Fruzsina Nagy
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Andrew M. Borman
- UK National Mycology Reference Laboratory, Public Health England, Science Quarter, Southmead Hospital, Bristol BS10 5NB, UK;
- Medical Research Council Centre for Medical Mycology (MRC CMM), University of Exeter, Exeter EX4 4QD, UK
| | - Awid Adnan
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.T.); (L.F.); (R.K.); (G.K.); (F.N.); (A.A.)
- Correspondence: ; Tel.: +36-52-255-425; Fax: +36-52-255-424
| |
Collapse
|
4
|
Kovács R, Nagy F, Tóth Z, Bozó A, Balázs B, Majoros L. Synergistic effect of nikkomycin Z with caspofungin and micafungin against
Candida albicans
and
Candida parapsilosis
biofilms. Lett Appl Microbiol 2019; 69:271-278. [DOI: 10.1111/lam.13204] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 05/11/2019] [Accepted: 07/29/2019] [Indexed: 12/12/2022]
Affiliation(s)
- R. Kovács
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
- Faculty of Pharmacy University of Debrecen Debrecen Hungary
| | - F. Nagy
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
| | - Z. Tóth
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
| | - A. Bozó
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
| | - B. Balázs
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
| | - L. Majoros
- Department of Medical Microbiology, Faculty of Medicine University of Debrecen Debrecen Hungary
| |
Collapse
|
5
|
Gil-Alonso S, Quindós G, Cantón E, Eraso E, Jauregizar N. Killing kinetics of anidulafungin, caspofungin and micafungin against Candida parapsilosis species complex: Evaluation of the fungicidal activity. Rev Iberoam Micol 2019; 36:24-29. [PMID: 30837186 DOI: 10.1016/j.riam.2018.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/26/2018] [Accepted: 12/18/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Candida parapsilosis, Candida metapsilosis and Candida orthopsilosis are emerging as relevant causes of candidemia. Moreover, they show differences in their antifungal susceptibility and virulence. The echinocandins are different in terms of in vitro antifungal activity against Candida. Time-kill (TK) curves represent an excellent approach to evaluate the fungicidal activity of antifungal drugs. AIMS To compare the fungicidal activities of anidulafungin, caspofungin and micafungin against C. parapsilosis species complex by TK curves. METHODS Antifungal activities of three echinocandins against C. parapsilosis, C. metapsilosis and C. orthopsilosis were studied by TK curves. Drug concentrations assayed were 0.25, 2 and 8μg/ml. CFU/ml were determined at 0, 2, 4, 6, 24 and 48h. RESULTS Killing activities of echinocandins were species-, isolates- and concentration-dependent. Anidulafungin reached the fungicidad endpoint for 6 out of 7 isolates (86%); it required between 13.34 and 29.67h to reach this endpoint for the three species studied, but more than 48h were needed against one isolate of C. orthopsilosis (8μg/ml). Caspofungin fungicidal endpoint was only achieved with 8μg/ml against one isolate of C. metapsilosis after 30.12h (1 out of 7 isolates; 14%). Micafungin fungicidal endpoint was reached in 12.74-28.38h (8μg/ml) against one isolate each of C. parapsilosis and C. orthopsilosis, and against both C. metapsilosis isolates (4 out of 7 isolates; 57%). CONCLUSIONS C. metapsilosis was the most susceptible species to echinocandins, followed by C. orthopsilosis and C. parapsilosis. Anidulafungin was the most active echinocandin against C. parapsilosis complex.
Collapse
Affiliation(s)
- Sandra Gil-Alonso
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar 'Microbios y Salud' (UFI 11/25), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain; Departamento de Farmacología, Unidad de formación e investigación multidisciplinar 'Microbios y Salud' (UFI 11/25), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain
| | - Guillermo Quindós
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar 'Microbios y Salud' (UFI 11/25), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain
| | - Emilia Cantón
- Unidad de Microbiología Experimental, Instituto Investigación Sanitaria La Fe, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Elena Eraso
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar 'Microbios y Salud' (UFI 11/25), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain
| | - Nerea Jauregizar
- Departamento de Farmacología, Unidad de formación e investigación multidisciplinar 'Microbios y Salud' (UFI 11/25), Facultad de Medicina y Enfermería, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
| |
Collapse
|
6
|
Comparison of Killing Activity of Micafungin Against Six Candida Species Isolated from Peritoneal and Pleural Cavities in RPMI-1640, 10 and 30% Serum. Mycopathologia 2018; 183:905-912. [PMID: 30382508 DOI: 10.1007/s11046-018-0302-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/11/2018] [Indexed: 12/20/2022]
Abstract
Currently echinocandins are recommended in Candida peritonitis and pleuritis. We determined micafungin killing rates (k values) at therapeutic concentrations (0.25-2 mg/L) in RPMI-1640 with and without 10 and 30% serum mimicking in vivo conditions against six Candida species isolated from peritoneal and pleural fluid. In RPMI-1640, micafungin was fungicidal against C. glabrata, C. krusei and C. kefyr within 2.27 ± 10.68, 2.69 ± 10.29 and 3.10 ± 4.41 h, respectively, while was fungistatic against C. albicans, C. tropicalis and C. parapsilosis. In 10% serum, ≥ 0.25, ≥ 0.5, ≥ 0.5 and ≥ 1 mg/L micafungin produced positive k values (killing) for all C. albicans, C. glabrata, C. kefyr and C. krusei, respectively. In 30% serum, 2 mg/L micafungin produced killing against all C. albicans, C. glabrata and C. kefyr isolates, but was ineffective against C. krusei, C. parapsilosis and 2 of 3 C. tropicalis. Micafungin exposure should be increased against non-albicans species to eradicate fungi from peritoneal and pleural cavities.
Collapse
|
7
|
Kardos T, Kovács R, Kardos G, Varga I, Bozó A, Tóth Z, Nagy F, Majoros L. Poor in vivo efficacy of caspofungin, micafungin and amphotericin B against wild-type Candida krusei clinical isolates does not correlate with in vitro susceptibility results. J Chemother 2018; 30:233-239. [PMID: 30025501 DOI: 10.1080/1120009x.2018.1487150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We determined micafungin, caspofungin and amphotericin B (AMB) minimum inhibitory concentration (MICs) and killing rates in RPMI-1640 and in RPMI-1640 with 50% serum against three Candida krusei bloodstream isolates. MIC ranges in RPMI-1640 were 0.125-0.25, 0.25 and 0.125-0.5 mg/L, in RPMI-1640 with 50% serum, MICs were 64-128-, 8- and 4-16-fold higher, respectively. In RPMI-1640 micafungin and caspofungin at 1, 4, 16 and 32 mg/L as well as AMB at 2 mg/L were fungicidal against all isolates in ≤3.96, ≤4.42 and 14.96 h, respectively. In RPMI-1640 with 50% serum, caspofungin was fungicidal for all isolates only at 32 mg/L, micafungin and AMB were fungistatic. In neutropenic mice, 5 mg/kg caspofungin and 1 mg/kg AMB were ineffective against two of the three isolates. Thus, in vivo efficacy of echinocandins and AMB is weak or absent against C. krusei. Prescribers treating C. krusei infections with echinocandins should watch out for clinical resistance and therapeutic failure.
Collapse
Affiliation(s)
- Tamás Kardos
- a Faculty of Medicine, Department of Pulmonology , University of Debrecen , Debrecen , Hungary.,b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| | - Renátó Kovács
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary.,c Faculty of Pharmacy , University of Debrecen , Debrecen , Hungary
| | - Gábor Kardos
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| | - Istvan Varga
- d Faculty of Dentistry , University of Debrecen , Debrecen , Hungary
| | - Aliz Bozó
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| | - Zoltán Tóth
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| | - Fruzsina Nagy
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| | - László Majoros
- b Faculty of Medicine, Department of Medical Microbiology , University of Debrecen , Debrecen , Hungary
| |
Collapse
|
8
|
Liu Y, Zhao Y, Guo DL, Liu WW, Liu YX. Synergistic Antimicrobial Activity of Berberine Hydrochloride, Baicalein and Borneol against Candida albicans. CHINESE HERBAL MEDICINES 2017. [DOI: 10.1016/s1674-6384(17)60115-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
9
|
Steinbach WJ, Lamoth F, Juvvadi PR. Potential Microbiological Effects of Higher Dosing of Echinocandins. Clin Infect Dis 2016; 61 Suppl 6:S669-77. [PMID: 26567286 DOI: 10.1093/cid/civ725] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The antifungal "paradoxical effect" has been described as the reversal of growth inhibition at high doses of echinocandins, most usually caspofungin. This microbiological effect appears to be a cellular compensatory response to cell wall damage, resulting in alteration of cell wall content and structure as well as fungal morphology and growth. In vitro studies demonstrate this reproducible effect in a certain percentage of fungal isolates, but animal model and clinical studies are less consistent. The calcineurin and Hsp90 cell signaling pathways appear to play a major role in regulating these cellular and structural changes. Regardless of the clinical relevance of this paradoxical growth effect, understanding the specific actions of echinocandins is paramount to optimizing their use at either standard or higher dosing schemes, as well as developing future improvements in our antifungal arsenal.
Collapse
Affiliation(s)
- William J Steinbach
- Division of Pediatric Infectious Diseases, Department of Pediatrics Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina
| | - Frédéric Lamoth
- Division of Pediatric Infectious Diseases, Department of Pediatrics Infectious Diseases Service, Department of Medicine Institute of Microbiology, Lausanne University Hospital, Switzerland
| | | |
Collapse
|
10
|
Domán M, Kovács R, Perlin DS, Kardos G, Gesztelyi R, Juhász B, Bozó A, Majoros L. Dose escalation studies with caspofungin against Candida glabrata. J Med Microbiol 2015; 64:998-1007. [PMID: 26296340 DOI: 10.1099/jmm.0.000116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Echinocandins are recommended as first-line agents against invasive fungal infections caused by Candida glabrata, which still carry a high mortality rate. Dose escalation of echinocandins has been suggested to improve the clinical outcome against C. glabrata. To address this possibility, we performed in vitro and in vivo experiments with caspofungin against four WT C. glabrata clinical isolates, a drug-susceptible ATCC 90030 reference strain and two echinocandin-resistant strains with known FKS mutations. MIC values for the clinical isolates in RPMI 1640 were ≤ 0.03 mg l(-1 ) but increased to 0.125-0.25 mg l(-1 )in RPMI 1640+50% serum. In RPMI 1640+50% serum, the replication of C. glabrata was weaker than in RPMI 1640.Caspofungin in RPMI 1640 at 1 and 4 mg l(-1) showed a fungicidal effect within 7 h against three of the four clinical isolates but was only fungistatic at 16 and 32 mg l(-1) (paradoxically decreased killing activity). In RPMI 1640+50% serum, caspofungin at ≥ 1 mg l(-1) was rapidly fungicidal (within 3.31 h) against three of the four isolates. In a profoundly neutropenic murine model, all caspofungin doses (1, 2, 3, 5 and 20 mg kg(-1) daily) decreased the fungal tissue burdens significantly (P < 0.05-0.001) without statistical differences between doses, but the mean fungal tissue burdens never fell below 105 cells (g tissue)(-1). The echinocandin-resistant strains were highly virulent in animal models and all doses were ineffective. These results confirm the clinical experience that caspofungin dose escalation does not improve efficacy.
Collapse
Affiliation(s)
- Marianna Domán
- Department of Medical Microbiology, University of Debrecen, Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, University of Debrecen, Hungary
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School-Rutgers, Newark, New Jersey, USA
| | - Gábor Kardos
- Department of Medical Microbiology, University of Debrecen, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacodynamics, University of Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacodynamics, University of Debrecen, Hungary
| | - Aliz Bozó
- Department of Medical Microbiology, University of Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, University of Debrecen, Hungary
| |
Collapse
|
11
|
Gil-Alonso S, Jauregizar N, Cantón E, Eraso E, Quindós G. Comparison of the in vitro activity of echinocandins against Candida albicans, Candida dubliniensis, and Candida africana by time-kill curves. Diagn Microbiol Infect Dis 2015; 82:57-61. [PMID: 25703894 DOI: 10.1016/j.diagmicrobio.2015.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/14/2015] [Accepted: 01/24/2015] [Indexed: 01/12/2023]
Abstract
Candida albicans remains the most common fungal pathogen. This species is closely related to 2 phenotypically similar cryptic species, Candida dubliniensis and Candida africana. This study aims to compare the antifungal activities of echinocandins against 7 C. albicans, 5 C. dubliniensis, and 2 C. africana strains by time-kill methodology. MIC values were similar for the 3 species; however, differences in killing activity were observed among species, isolates, and echinocandins. Echinocandins produced weak killing activity against the 3 species. In all drugs, the fungicidal endpoint (99.9% mortality) was reached at ≤31 h with ≥0.5 μg/mL for anidulafungin in 4 C. albicans and 1 C. dubliniensis, for caspofungin in 1 C. albicans and 2 C. dubliniensis, and for micafungin in 4 C. albicans and 1 C. dubliniensis. None of echinocandins showed lethality against C. africana. Identification of these new cryptic species and time-kill studies would be recommendable when echinocandin treatment fails.
Collapse
Affiliation(s)
- Sandra Gil-Alonso
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar "Microbios y Salud" (UFI 11/25), Facultad de Medicina y Odontología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain; Departamento de Farmacología, (UFI 11/25), Facultad de Medicina y Odontología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
| | - Nerea Jauregizar
- Departamento de Farmacología, (UFI 11/25), Facultad de Medicina y Odontología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
| | - Emilia Cantón
- Unidad de Microbiología Experimental, Instituto Investigación Sanitaria La Fe, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
| | - Elena Eraso
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar "Microbios y Salud" (UFI 11/25), Facultad de Medicina y Odontología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
| | - Guillermo Quindós
- Departamento de Inmunología, Microbiología y Parasitología, Unidad de formación e investigación multidisciplinar "Microbios y Salud" (UFI 11/25), Facultad de Medicina y Odontología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
| |
Collapse
|
12
|
Abstract
Successful treatment of infectious diseases requires choice of the most suitable antimicrobial agent, comprising consideration of drug pharmacokinetics (PK), including penetration into infection site, pathogen susceptibility, optimal route of drug administration, drug dose, frequency of administration, duration of therapy, and drug toxicity. Antimicrobial pharmacokinetic/pharmacodynamic (PK/PD) studies consider these variables and have been useful in drug development, optimizing dosing regimens, determining susceptibility breakpoints, and limiting toxicity of antifungal therapy. Here the concepts of antifungal PK/PD studies are reviewed, with emphasis on methodology and application. The initial sections of this review focus on principles and methodology. Then the pharmacodynamics of each major antifungal drug class (polyenes, flucytosine, azoles, and echinocandins) is discussed. Finally, the review discusses novel areas of pharmacodynamic investigation in the study and application of combination therapy.
Collapse
|
13
|
Vanstraelen K, Lagrou K, Maertens J, Wauters J, Willems L, Spriet I. The Eagle-like effect of echinocandins: what’s in a name? Expert Rev Anti Infect Ther 2014; 11:1179-91. [DOI: 10.1586/14787210.2013.841543] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
14
|
Walraven CJ, Bernardo SM, Wiederhold NP, Lee SA. Paradoxical antifungal activity and structural observations in biofilms formed by echinocandin-resistant Candida albicans clinical isolates. Med Mycol 2013; 52:131-139. [PMID: 24576999 DOI: 10.1093/mmy/myt007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Echinocandin-resistant clinical isolates of Candida albicans have been reported, and key-hot spot mutations in the FKS1 gene, which encodes a major glucan synthase subunit, have been identified in these (caspofungin-resistant [CAS-R]) strains. Although these mutations result in phenotypic resistance to echinocandins in planktonic cells, there is little data on antifungal susceptibilities of CAS-R C. albicans strains within biofilms. Thus, we analyzed biofilms formed by 12 C. albicans CAS-R clinical strains in which we previously identified FKS1 hot-spot mutations and compared the sessile antifungal and paradoxical activity of anidulafungin (ANID), caspofungin (CAS), and micafungin (MICA). Biofilms were formed in a 96-well static microplate model and assayed using both tetrazolium-salt reduction and crystal violet assays, as well as examination by scanning electron microscopy. We first sought to assess biofilm formation and structure in these fks1 mutants and found that the biofilm mass and metabolic activities were reduced in most of the fks1 mutants as compared with reference strain SC5314. Structural analyses revealed that the fks1 mutant biofilms were generally less dense and had a clear predominance of yeast and pseudohyphae, with unusual "pit"-like cell surface structures. We also noted that sessile minimum inhibitory concentrations (MICs) to ANID, CAS, and MICA were higher than planktonic MICs of all but one strain. The majority of strains demonstrated a paradoxical effect (PE) to particular echinocandins, in either planktonic or sessile forms. Overall, biofilms formed by echinocandin-resistant clinical isolates demonstrated varied PEs to echinocandins and were structurally characterized by a preponderance of yeast, pseudohyphae, and pit-like structures.
Collapse
Affiliation(s)
- Carla J Walraven
- University of New Mexico Health Science Center, Albuquerque, Albuquerque, New Mexico, USA.,New Mexico Veterans Healthcare System, Albuquerque, New Mexico, USA
| | - Stella M Bernardo
- University of New Mexico Health Science Center, Albuquerque, Albuquerque, New Mexico, USA.,New Mexico Veterans Healthcare System, Albuquerque, New Mexico, USA
| | - Nathan P Wiederhold
- University of Texas at Austin College of Pharmacy, Austin, Texas and San Antonio, Texas, USA.,University of Texas Health Science Center at San Antonio, Pharmacotherapy Education and Research Center, San Antonio, Texas, USA
| | - Samuel A Lee
- University of New Mexico Health Science Center, Albuquerque, Albuquerque, New Mexico, USA.,New Mexico Veterans Healthcare System, Albuquerque, New Mexico, USA
| |
Collapse
|
15
|
Kovács R, Gesztelyi R, Berényi R, Domán M, Kardos G, Juhász B, Majoros L. Killing rates exerted by caspofungin in 50 % serum and its correlation with in vivo efficacy in a neutropenic murine model against Candida krusei and Candida inconspicua. J Med Microbiol 2013; 63:186-194. [PMID: 24184471 DOI: 10.1099/jmm.0.066381-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Killing rates (K) of 1-32 µg ml(-1) caspofungin were determined in RPMI-1640 and in 50 % serum using time-kill methodology against three Candida krusei (MICs of all three isolates 0.25 µg ml(-1) in RPMI-1640 and 2 µg ml(-1) in serum) and three Candida inconspicua clinical isolates (MIC ranges 0.06-0.12 µg ml(-1) in RPMI-1640 and 0.25-0.5 µg ml(-1) in serum), against C. krusei ATCC 6258 and against one C. krusei isolate that was resistant to echinocandins (MIC 8 µg ml(-1) in RPMI-1640 and 32 µg ml(-1) in serum). In RPMI-1640, the highest mean K values were observed at 4 (-1.05 h(-1)) and 16 (-0.27 h(-1)) μg ml(-1) caspofungin for C. krusei and C. inconspicua clinical isolates, respectively. In 50 % serum, mean K value ranges at 1-32 and 4-32 µg ml(-1) concentrations for C. inconspicua and C. krusei were -1.12 to -1.44 and -0.42 to -0.57 h(-1), respectively. While K values against C. krusei in RPMI-1640 and 50 % serum were comparable, serum significantly increased the killing rate against C. inconspicua (P<0.0003 for all tested concentrations). In a neutropenic murine model, daily caspofungin at 1, 2, 3, 5 and 15 mg kg(-1) significantly decreased the fungal tissue burden of C. inconspicua in the kidneys (P<0.05-0.001). Against C. krusei, doses of 3, 5 and 15 mg kg(-1) caspofungin were effective (P<0.05-0.01). All effective doses were comparably efficacious for both species. Only the highest 15 mg kg(-1) caspofungin dose was effective even against the echinocandin-resistant C. krusei isolate. In 50 % serum, killing was concentration independent at effective concentrations (≥4 and ≥1 µg ml(-1) for C. krusei and C. inconspicua, respectively), suggesting that the efficacy of dose escalation is questionable. These in vitro results were also supported by the murine model.
Collapse
Affiliation(s)
- Renátó Kovács
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacodynamics, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Réka Berényi
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Marianna Domán
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Gábor Kardos
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacodynamics, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Hungary
| |
Collapse
|
16
|
Echinocandins: production and applications. Appl Microbiol Biotechnol 2013; 97:3267-84. [PMID: 23463246 DOI: 10.1007/s00253-013-4761-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 10/27/2022]
Abstract
The first echinocandin-type antimycotic (echinocandin B) was discovered in the 1970s. It was followed by the isolation of more than 20 natural echinocandins. These cyclic lipo-hexapeptides are biosynthesized on non-ribosomal peptide synthase complexes by different ascomycota fungi. They have a unique mechanism of action; as non-competitive inhibitors of β-1,3-glucan synthase complex they target the fungal cell wall. Results of the structure-activity relationship experiments let us develop semisynthetic derivatives with improved properties. Three cyclic lipohiexapeptides (caspofungin, micafungin and anidulafungin) are currently approved for use in clinics. As they show good fungicidal (Candida spp.) or fungistatic (Aspergillus spp.) activity against the most important human pathogenic fungi including azole-resistant strains, they are an important addition to the antifungal armamentarium. Some evidence of acquired resistance against echinocandins has been detected among Candida glabrata strains in recent years, which enhanced the importance of data collected on the mechanism of acquired resistance developing against the echinocandins. In this review, we show the structural diversity of natural echinocandins, and we summarize the emerging data on their mode of action, biosynthesis and industrial production. Their clinical significance as well as the mechanism of natural and acquired resistance is also discussed.
Collapse
|
17
|
Comparison of in vitro and vivo efficacy of caspofungin against Candida parapsilosis, C. orthopsilosis, C. metapsilosis and C. albicans. Mycopathologia 2012; 174:311-8. [PMID: 22565489 DOI: 10.1007/s11046-012-9554-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 04/23/2012] [Indexed: 10/28/2022]
Abstract
Caspofungin activity was determined in vitro and in vivo against three Candida orthopsilosis, three C. metapsilosis, two C. parapsilosis sensu stricto and two C. albicans isolates. MIC values and killing activity were determined in RPMI-1640 plus 50 % human serum. Neutropenic (cyclophosphamide-treated) mice were infected intravenously. Five-day intraperitoneal treatment with caspofungin was started after 24 h postinfection. Kidney burden was analyzed using the Kruskal-Wallis test with Dunn's post-test. In killing studies, caspofungin was fungistatic and fungicidal against C. albicans at ≥0.25 and ≥2 μg/ml concentrations, respectively. Caspofungin was fungistatic at ≥8-16, ≥2-8 and at ≥2-8 μg/ml against C. parapsilosis, C. orthopsilosis and C. metapsilosis, respectively. In the murine model, C. albicans was inhibited by 1, 2 and 5 mg/kg of caspofungin (P < 0.001 compared to the controls). Against C. parapsilosis, only 5 mg/kg caspofungin was effective against both isolates (P < 0.05). Two and five mg/kg of caspofungin was effective against all C. orthopsilosis and C. metapsilosis isolates (P < 0.05 to <0.001). Serum-based killing tests proved to be useful in predicting in vivo efficacy of caspofungin against four Candida species. Caspofungin at clinically attainable concentrations proved to be effective against all four species.
Collapse
|