Abstract
purpose. Fungal ocular infections cause significant ocular morbidity, particularly when diagnosis and treatment are delayed. Accurate morphologic identification of Fusarium spp. beyond the genus is time-consuming and insensitive. It was the purpose of this study to examine the usefulness of the nuclear ribosomal RNA (rRNA) internal transcribed spacer regions (ITS1 and -2) to detect and differentiate Fusarium spp. responsible for ocular infections.
methods. Fifty-eight archived isolates from ocular sources of 52 patients diagnosed with Fusarium keratitis at the Bascom Palmer Eye Institute (Miami, FL) from April 2000 to May 2007 were analyzed. The archived samples, which were initially classified according to morphologic characteristics, were analyzed by DNA sequence data generated from the ITS regions of the rRNA genes.
results. Fifteen distinct sequences were identified among the 58 isolates. Sequence analysis identified the isolates as Fusarium solani (75%), F. oxysporum (16%), F. incarnatum-equiseti (5%), F. dimerum (2%), and one Fusarium sp. (2%) that was not classified within any species complex. Species identification based on sequence data correlated well with the morphologic classification when performed by a mycology reference laboratory, but a higher rate of mismatch was observed based on identification by a nonreference laboratory.
conclusions. Most of the isolates of Fusarium ocular infections belong to the F. solani or F. oxysporum species complexes. Morphologic classification at the species level yielded inconsistent results at a general microbiology laboratory. In contrast, the sequence variation within the ITS region allowed reliable and faster discrimination of the isolates at both the genus and species level.
Fungal corneal ulcers are a prevalent cause of ocular morbidity throughout the world,
1 and the incidence has increased significantly over the past three decades,
2 3 largely as the result of increases in patient risk factor profiles. The etiology of infectious keratitis is variable and largely dependent on geographic and climatic variables, as well as patient risk factor profiles. Fungal organisms are the etiologic agent in 1.2% to 62% of infectious keratitis case and are significantly more common in tropical and subtropical regions.
4 5 6 7 8 Fusarium is the most common genus isolated in cases of fungal keratitis in tropical and subtropical regions, where they represent as much as 45% to 73% of fungal keratitis cases.
2 3 4 7 9
Diagnosis of fungal keratitis is challenging due to limitations in culture- and microscopy-based methods of identification. Culture-based methods are labor intensive and time consuming, requiring specially trained mycologists to properly identify isolates at the species level, typically yielding positive results 3 to 7 days after initial presentation. Identification based on histopathologic examination of corneal scrapings allows for a rapid diagnosis of a fungal infection, but has highly variable sensitivity and is less effective at differentiating isolates at the species level.
8 This delay in identification of the etiologic agent and initiation of appropriate antimicrobial coverage undoubtedly results in increased ocular morbidity. Molecular diagnostic techniques have been suggested to address these limitations and can significantly improve our diagnostic capabilities as well as patient outcomes in the future.
The increasing reports of
Fusarium as a human pathogen in ocular infections have generated an interest in finding a more rapid, accurate, and consistent method for diagnosis and classification. Fortunately, numerous molecular techniques, including PCR-based technology and microarray technology have shown promise in offering a solution in both human and animal experimental models.
10 11 12 13 14 15 16 17 18 19 20 Recent genotyping studies have shown that DNA sequence-based methods are useful for species identification and subtyping of
Fusarium.
16 17 21 22 Accurate species identification of
Fusarium spp. is important not only in promoting our understanding of the spectrum of fusaria that are pathogenic to the eye, but in gaining important prognostic and therapeutic information for the patient and clinician in the future.
Many different genes have provided the basis for the development of molecular-based identification techniques, including ribosomal RNA (rRNA), translation elongation factor (EF-1α), the second largest subunit of RNA polymerase II (RPB2), and domains D1/D2 of the nuclear large subunit (LSU).
17 21 23 24 Many fungal genotyping studies have relied on the rRNA gene complex for rapid species identification.
13 14 25 26 27 28 29 30 This gene family comprises four ribosomal rRNA genes: the 26 to 28S, 18S, 5.8S, and 5S genes, which are arranged as head-to-tail tandem repeats separated by the spacer regions, the internal transcribed spacer region (ITS) and the intergenic spacer region (IGS;
Fig. 1 ), Although rRNA genes are highly conserved, the ITS regions are typically variable and rich in informative sites; hence, their usefulness for phylogenetic classification.
28 29 Although the ability of the ITS region to differentiate medically important species within
Fusarium species, complexes have been reported, and no study has been undertaken to fully examine the utility of the allelic variability within this single locus to differentiate
Fusarium spp. isolates from ocular sources alone. In this study, we employed sequence data analysis of the ITS region as well as traditional morphologic classification to elucidate the phylogenetic diversity of
Fusarium spp. strains isolated from ocular tissue and contact lens paraphernalia of patients with
Fusarium keratitis in south Florida.
PCR reactions were performed with 200 ng of genomic DNA. The primers F18S (5′-GCGGAGGGATCATTACCGAGTT-3′) and F28S (5′-CAGCGGGTATTCCTACCTGATC-3′) (Invitrogen) were designed to specifically target Fusarium spp. F18S primer is located at the end of the 18S ribosomal DNA at position 520 to 540 of F. solani reference strain Fs-27 (GenBank EF432243; http://www.ncbi.nlm.nih.gov/Genbank; provided in the public domain by the National Center for Biotechnology Information, Bethesda, MD), and F28S is located at the beginning of the 28S rRNA at position 41-62 of the sequence EF432243. The described set of primers amplified the internal transcribed spacer region comprising ITS1, ITS2, and 5.8S rRNA. The PCR reaction was performed with a polymerase system kit (Accuprime Taq DNA Polymerase System; Invitrogen). The 25-μL PCR mixture contained 1 μL (200 ng) of DNA template, 2.5 μL of buffer II solution (containing the dNTPs and MgCl2), 1 μL of each 10 μM primer (F18S and F28S), 1 μL of Taq DNA polymerase (Invitrogen), and 18.5 μL of distilled water. PCR reactions were performed in a thermocycler (iCycler; Bio-Rad, Hercules, CA) and used 1 cycle at 95°C for 3 minutes, followed by 45 cycles with a denaturation step at 95°C for 30 seconds, an annealing step at 55°C for 30 seconds, and an extension step at 68°C for 2 minutes. A negative control was included in all experiments. The detection of amplified products was performed by electrophoresis of an aliquot of 5 μL of each amplicon in a 1% agarose gel with ethidium bromide 0.02% in 1× Tris-acetate-EDTA (TAE) buffer. The DNA bands were visualized under UV illumination (Universal Hood II; Bio-Rad). A 1-kb molecular weight ladder (Invitrogen) was included in each run. PCR products were purified with a spin kit (Geneclean; MP Biomedicals, Solon, OH) according to the manufacturer’s instructions.
Direct sequencing of PCR products was performed by Genewiz, Inc. (South Plainfield, NJ, with BigDye version 3.1; Applied Biosystems, Inc. [ABI], Foster City, CA). The reactions were run on a DNA analyzer (model 3730; ABI). The PCR amplification primers, F18S and F28S, were used as the sequencing primers, and the PCR products were sequenced on both strands in duplicate or triplicate to assure sequence fidelity.
In this study, we examined the genetic diversity of Fusarium spp. isolates derived from patients with infectious keratitis diagnosed at the Bascom Palmer Eye Institute. Toward this end, we studied the feasibility of using the ITS region for the detection and identification of Fusarium spp. from ocular sources to the species level. In addition, we compared this molecular classification technique to classification based on examination of morphologic characteristics.
Fusarium spp. isolates causing ocular infections were classified within four main species complexes—FSSC, FOSC, FIESC, and FDSC— with a relative frequency similar to that previously reported.
21 22 Of the isolates, 57% were represented by the three most common haplotypes (a, c, k). O’Donnell et al.
21 22 genotyped 191 isolates using multilocus sequence typing (MLST) of the nuclear large rRNA subunit (LSU), translation elongation factor (
EF-1α), and two contiguous regions of the RNA polymerase II second largest subunit (
RPB2). They used isolates from ocular and environmental sources obtained from the Centers for Disease Control (CDC) investigation of a contact lens–associated
Fusarium keratitis outbreak. Their phylogenetic study nested the isolates causing ocular infection into five different species complexes: FSSC (62%), FOSC (29%), GFSC (6%;
Gibberella fujikuroi species complex), FIESC (4%), and FDSC (1.0%). No GFSC or FCSC isolates were identified in the present study, probably as a result of small sample size or differences in sampling region compared with other studies. Of note, only one case of FCSC-associated keratitis has been reported in the literature.
34
The isolate EU721689 exhibited significant sequence variability (14%–18%) when compared to other isolates in our study
(Table 2) . This isolate may be representative of another
Fusarium species complex still not defined or may represent an organism from another genus. However, both microbiology laboratories morphologically classified this isolate as
Fusarium spp. The clinical outcome was typical of an infection caused by a non-
F. solani isolate, with good final visual acuity and without the need for surgical intervention. A database search of GenBank identified the isolate as
Colletotrichum spp.
, Nectria spp., or
Fusarium spp.
Taxonomic identification of
Fusarium spp. has its limitations in a diagnostic setting. In this study, genus level taxonomic identification was 100% accurate at both BPEI-OML and TFTL, compared with genotypic classification. Species classification of the 30 selected isolates performed by TFTL was accurate and in concordance 100% of the time with the genotypic data. In contrast, a substantial discrepancy was observed in species assignment performed at BPEI-OML, where only 30 of the 58 isolates were assigned a species designation, which proved to have an accuracy of 50% when compared to the genotypic identification, because of low sensitivity for the
F. solani isolates. Because nonreference clinical laboratories are not typically equipped to identify fungal organisms to the species level, this result is not altogether unexpected. Laboratory species designation based solely on microscopic and morphologic traits can be prone to misinterpretations because morphologic characteristics of certain fungal elements are not always clear. In fact, strains belonging to the same species may display different morphologic characteristics at different growth stages.
14 In addition, micro- and macroscopic characteristics may be influenced by media, age of culture, and identification schema.
31 Therefore, the success of this traditional method of identification relies on the taxonomic experience of the personnel who perform the tests.
Genus- and species-specific identification of fungi using microbiologic techniques is also time-consuming. Such techniques generally require approximately 3 and 7 days, respectively, even when undertaken at a fungal reference laboratory. In contrast, the use of PCR and sequence analysis is capable of identification of Fusarium isolates to the genus and species level in less than 24 hours. In this study, sequencing was undertaken by another institution which increased the total time required for species identification to 3 days.
The present study highlights two attractive features of the ITS region: the region aligned well across the spectrum of isolates represented in ocular infections; and the nucleotide variation provided strong bootstrap support to allow for the placement of 98% of the isolates within one of six monophyletic species complexes
(Table 2) . In addition, the ITS region lies within a multicopy gene, which is important in a clinical diagnostic setting, particularly in the field of ophthalmology, where sample size is very limited. The multicopy nature of the gene would theoretically result in increased assay sensitivity when applied within the context of a PCR-based diagnostic test.
11
Although the allelic variation within the ITS region allowed reliable placement of most isolates within one of the six species complex groups, the ability of this region to clearly differentiate distinct clades within each of these six species complexes is limited, particularly when compared with MLST.
21 22 Although this MLST technique described by O’Donnell et al.
21 22 is capable of more detailed classification, this level of identification may not be required in a clinical setting. When developing a cost-effective and efficient molecular-based analysis in a clinical setting, it is important to determine the level of identification that remains clinically relevant. Moreover, to what level do differences exist among the different species with regard to pathogenicity and antifungal susceptibility profiles that can potentially influence management decisions of the treating physician?
The
Fusarium genus is largely resistant, both in vivo and in vitro, to the current available antifungal agents.
22 24 35 However, previous studies have demonstrated antifungal MICs that are typically higher and more variable for
Fusarium than for other pathogenic filamentous fungi
36 ; thus, it may be beneficial to establish susceptibility profiles among the different species as determined by molecular classification techniques. Repeatedly, broth microdilution studies based on NCCLS guidelines have demonstrated
F. solani to carry higher levels of resistance to available antifungal agents (in particular amphotericin B and voriconazole) than non-
F. solani species.
24 36 37 Similarly, O’Donnell et al.
22 studied the in vitro activity of 10 antifungals against 20 isolates representing 18 species that span the breadth of the FSSC phylogeny and found broad resistance across this complex without species-specific differences in susceptibility patterns.
In a recent report of 52 patients with Fusarium keratitis, differences in clinical characteristics among the different species complexes concluded that infections due to organisms within the FSSC, in contrast to non-FSSC organisms, were associated with worse final best corrected visual acuity, a longer resolution time, and higher penetrating keratoplasty rate (Oechsler RA et al. IOVS 2008;49:ARVO E-Abstract 2495). These findings suggest higher pathogenicity among the FSSC isolates in the setting of infectious keratitis.
Patient 9 was the only patient from which isolates with different haplotypes were recovered. The first isolate was from a corneal scraping of the right eye in April 2004, and the second isolate was from the patient’s right contact lens, also cultured in April 2004. This finding suggests that
Fusarium isolates obtained from contact lenses or associated paraphernalia do not necessarily correlate with the organism causing the ocular infection. Of note, one case has been reported in the literature in which two different
Fusarium genotypes were isolated from the same eye of a patient with infectious keratitis.
7 Although difficult, it may be clinically important to identify a dual infection, as antifungal susceptibility patterns are known to be widely variable among the different
Fusarium isolates,
22 24 35 and the choice of antifungal medication may be influenced by such information.
Although in vitro and clinical correlation studies have demonstrated differences in susceptibility and pathogenicity profiles among the Fusarium species complexes, studies using an animal model of infectious keratitis are necessary to compare the pathogenic potentials as well as the in vivo susceptibility profiles of each species complex. Nonetheless, these existing reports encourage proper identification to the species complex level, which may aid the clinician by providing prognostic and therapeutic information that may, in fact, influence clinical decisions.
In summary, the ITS region provides a sufficient genetic scaffolding to detect and reliably differentiate Fusarium spp. isolates that cause ocular infections into one of six species complex groupings, a level of identification that appears to hold clinical relevance. In theory, the ITS region is an ideal candidate on which to base the development of a rapid molecular test for the diagnosis of infectious etiologies. When compared with MLSTs, the ITS region offers a less complex, more efficient, and more cost-effective means of differentiating ocular Fusarium isolates to a level that will influence clinical decision-making.
Such DNA-based diagnostic tests show significant promise in allowing precise and rapid diagnosis of fungal ocular infections, and their design and implementation will certainly hasten the initiation of appropriate antimicrobial therapy and guide clinical management decisions, with the potential of decreasing the ocular morbidity associated with fungal ocular infections.
This article is a portion of a thesis that was presented as a part of the requirement for election to membership in the American Ophthalmological Society (AOS). The complete thesis will be published in the
AOS Transactions.
Supported by the University of Miami Wallace H. Coulter Center for Translational Research; Research to Prevent Blindness; National Eye Institute Core Grant P30 EY014801; and an unrestricted grant from Bausch & Lomb, Inc.
Submitted for publication August 20, 2008; revised October 7 and November 18, 2008; accepted March 23, 2009.
Disclosure:
R. A. Oechsler, None;
M. R. Feilmeier, None;
D. R. Ledee, None;
D. Miller, None;
M.R. Diaz, None;
M.E. Fini, None;
J.W. Fell, None;
E.C. Alfonso, None
The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked “
advertisement” in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Corresponding author: Rafael A. Oechsler, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, 1638 NW 10th Avenue, Room 403, Miami, FL 33136;
[email protected].
Table 1. Summary of Fusarium spp. Isolates Examined
Table 1. Summary of Fusarium spp. Isolates Examined
| Patient | Source | Year | BPEI-OML Classification | Reference Lab Classification | Genotype | Haplotype | GenBank Accession Number |
| 1 | Cornea | 2005 | F. solani | FSSC | FSSC | a | EU721672* |
| 2 | CL case | 2006 | Fusariumsp. | FSSC | FSSC | a | EU721721 |
| 3 | Cornea | 2006 | F. oxysporum | FSSC | FSSC | b | EU721688* |
| 4 | CL | 2003 | Fusariumsp. | — | FSSC | a | EU721708 |
| 5 | Cornea | 2006 | Fusariumsp. | FSSC | FSSC | a | EU721704 |
| 6 | CL | 2006 | Fusariumsp. | FSSC | FSSC | b | EU721683 |
| 7 | Cornea | 2004 | Fusariumsp. | — | FSSC | b | EU721701 |
| 8 | Cornea | 2006 | Fusariumsp. | — | FSSC | b | EU721671 |
| 9, † | Cornea | 2004 | F. solani | — | FSSC | a | EU721677 |
| 9, † | CL | 2004 | F. solani | — | FSSC | i | EU721674* |
| 10 | Cornea | 2006 | F. solani | — | FSSC | d | EU721693* |
| 11 | Cornea | 2004 | F. oxysporum | — | FSSC | c | EU721724* |
| 12, † | Cornea | 2006 | Fusariumsp. | — | FSSC | c | EU721692 |
| 12, † | Cornea | 2006 | Fusariumsp. | FSSC | FSSC | c | EU721690 |
| 13 | Cornea | 2007 | F. solani | — | FSSC | e | EU721680* |
| 14 | Cornea | 2007 | F. oxysporum | — | FSSC | c | EU721686 |
| 15 | Cornea | 2005 | Fusariumsp. | FSSC | FSSC | f | EU721702* |
| 16 | Cornea | 2004 | Fusariumsp. | — | FSSC | c | EU721722 |
| 17 | Cornea | 2005 | F. oxysporum | — | FSSC | c | EU721714 |
| 18 | Vitreous | 2005 | Fusariumsp. | — | FSSC | c | EU721678 |
| 19, † | Cornea | 2006 | Fusariumsp. | FSSC | FSSC | c | EU721673 |
| 19, † | CL | 2006 | Fusariumsp. | — | FSSC | c | EU721711 |
| 20 | Cornea | 2005 | F. oxysporum | — | FSSC | c | EU721696 |
| 21 | Cornea | 2006 | F. oxysporum | FSSC | FSSC | c | EU721717 |
| 22 | CL | 2006 | Fusariumsp. | FSSC | FSSC | c | EU721681 |
| 23 | Cornea | 2006 | Fusariumsp. | — | FSSC | c | EU721703 |
| 24 | Cornea | 2007 | F. solani | — | FSSC | g | EU721679* |
| 25 | Cornea | 2006 | Fusariumsp. | FSSC | FSSC | g | EU721705 |
| 26 | AC | 2006 | F. solani | — | FSSC | h | EU721691* |
| 27 | Cornea | 2004 | F. solani | — | FSSC | g | EU721695 |
| 28 | Cornea | 2000 | F. oxysporum | FSSC | FSSC | g | EU721687 |
| 29 | Cornea | 2007 | F. oxysporum | — | FSSC | g | EU721684 |
| 30 | Cornea | 2007 | F. oxysporum | — | FSSC | g | EU721699 |
| 31 | Cornea | 2005 | F. oxysporum | — | FSSC | g | EU721698 |
| 32 | Cornea | 2007 | F. oxysporum | FSSC | FSSC | g | EU721697 |
| 33 | Cornea | 2006 | Fusariumsp. | — | FSSC | g | EU721675 |
| 34 | Cornea | 2006 | F. oxysporum | — | FSSC | g | EU721725 |
| 35 | Cornea | 2006 | F. oxysporum | — | FSSC | g | EU721719 |
| 36 | Cornea | 2005 | F. solani | FSSC | FSSC | g | EU721676 |
| 37 | Cornea | 2007 | F. solani | FSSC | FSSC | j | EU721670* |
| 38 | Cornea | 2004 | F. solani | — | FSSC | i | EU721694 |
| 39, † | AC | 2004 | F. oxysporum | FSSC | FSSC | i | EU721715 |
| 39, † | AC | 2006 | F. oxysporum | FSSC | FSSC | i | EU721700 |
| 40 | Cornea | 2006 | Fusariumsp. | — | FSSC | j | EU721727 |
| 41, † | CL case | 2006 | F. oxysporum | FOSC | FOSC | k | EU721709* |
| 41, † | CL | 2006 | F. oxysporum | FOSC | FOSC | k | EU721718 |
| 42 | Cornea | 2006 | Fusariumsp. | FOSC | FOSC | k | EU721712 |
| 43, † | CL case | 2005 | Fusariumsp. | FOSC | FOSC | k | EU721710 |
| 43, † | CL | 2006 | Fusariumsp. | FOSC | FOSC | k | EU721713 |
| 44 | Cornea | 2006 | Fusariumsp. | FOSC | FOSC | k | EU721685 |
| 45 | Cornea | 2006 | F. oxysporum | FOSC | FOSC | k | EU721682 |
| 46 | CL | 2006 | Fusariumsp. | FOSC | FOSC | l | EU721720* |
| 47 | CL | 2006 | Fusariumsp. | FOSC | FOSC | k | EU721723 |
| 48 | CL | 2006 | F. oxysporum | FIESC | FIESC | m | EU721716* |
| 49 | CL | 2006 | Fusariumsp. | FIESC | FIESC | m | EU721726 |
| 50 | Cornea | 2006 | Fusariumsp. | FIESC | FIESC | m | EU721706 |
| 51 | Cornea | 2004 | Fusariumsp. | — | FDSC | n | EU721707* |
| 52 | Cornea | 2007 | Fusariumsp. | FIESC | No fit | o | EU721689* |
Table 2. Phylogenetic Distance among the 15 Different Haplotypes and Outgroup
Table 2. Phylogenetic Distance among the 15 Different Haplotypes and Outgroup
| Percent Identity | | | | | | | | | | | | | | | | Accession No. |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | |
| 1 | — | 96.6 | 99.6 | 98.5 | 98.3 | 98.8 | 85.3 | 98.5 | 99.0 | 98.3 | 84.2 | 87.6 | 87.8 | 87.8 | 98.1 | 81.1 | EU721670 |
| 2 | 3.5 | — | 86.4 | 88.4 | 86.6 | 99.8 | 85.5 | 98.4 | 98.7 | 98.2 | 83.3 | 87.4 | 87.2 | 87.1 | 98.5 | 79.7 | EU721672 |
| 3 | 0.2 | 3.7 | — | 98.3 | 88.1 | 96.6 | 85.3 | 98.3 | 98.7 | 98.1 | 84.2 | 87.8 | 87.8 | 87.8 | 97.9 | 80.9 | EU721674 |
| 4 | 1.5 | 3.7 | 1.7 | — | 98.5 | 96.6 | 88.0 | 100.0 | 99.0 | 98.5 | 84.4 | 88.1 | 88.5 | 87.8 | 97.8 | 81.2 | EU721678 |
| 5 | 1.7 | 3.4 | 1.8 | 1.5 | — | 96.8 | 85.7 | 98.5 | 99.4 | 98.5 | 84.4 | 87.8 | 88.1 | 87.4 | 98.7 | 81.8 | EU721680 |
| 6 | 3.2 | 0.2 | 3.5 | 3.4 | 3.2 | — | 95.7 | 98.8 | 98.9 | 98.5 | 83.5 | 87.6 | 87.4 | 87.4 | 96.7 | 79.9 | EU721698 |
| 7 | 16.4 | 16.1 | 16.4 | 15.6 | 15.9 | 15.9 | — | 86.0 | 86.0 | 86.0 | 84.3 | 85.8 | 86.1 | 85.6 | 86.2 | 81.9 | EU721689 |
| 8 | 1.5 | 3.7 | 1.7 | 0.0 | 1.5 | 3.4 | 15.6 | — | 99.0 | 98.5 | 84.3 | 88.1 | 85.1 | 87.8 | 98.9 | 81.2 | EU721691 |
| 9 | 1.1 | 3.4 | 1.3 | 1.1 | 0.6 | 3.2 | 15.5 | 1.1 | — | 98.8 | 84.4 | 87.4 | 88.1 | 87.2 | 98.0 | 81.6 | EU721893 |
| 10 | 1.7 | 3.9 | 1.9 | 1.5 | 1.5 | 3.7 | 15.6 | 1.5 | 1.3 | — | 84.4 | 87.6 | 87.9 | 87.4 | 99.8 | 81.4 | EU721702 |
| 11 | 17.8 | 19.0 | 17.8 | 17.5 | 17.5 | 18.7 | 17.6 | 17.7 | 17.5 | 17.5 | — | 85.4 | 86.5 | 86.2 | 84.6 | 80.1 | EU721707 |
| 12 | 13.9 | 13.9 | 13.6 | 13.0 | 13.6 | 13.6 | 15.8 | 13.0 | 13.8 | 13.5 | 15.0 | — | 95.6 | 99.8 | 87.9 | 80.3 | EU721709 |
| 13 | 13.3 | 14.1 | 13.3 | 12.5 | 13.0 | 13.8 | 15.4 | 12.5 | 13.0 | 13.2 | 14.9 | 4.5 | — | 95.4 | 88.1 | 82.7 | EU721716 |
| 14 | 13.4 | 14.1 | 13.4 | 13.3 | 13.8 | 13.9 | 16.1 | 13.3 | 14.1 | 13.8 | 15.3 | 0.2 | 4.8 | — | 87.6 | 80.1 | EU721720 |
| 15 | 1.9 | 3.7 | 2.1 | 1.3 | 1.3 | 3.4 | 15.3 | 1.3 | 1.1 | 0.2 | 17.2 | 13.3 | 13.0 | 13.5 | — | 81.6 | EU721724 |
| 16 | 21.8 | 23.8 | 22.1 | 21.7 | 21.1 | 23.5 | 20.8 | 21.7 | 21.1 | 21.4 | 23.2 | 22.9 | 19.7 | 23.2 | 21.1 | — | Lecanicillium lecanii DQ449654 |
Table 3. Genetic Identification Breakdown of the 58 Isolates and Comparison to the Reference Genotypic Classification for Medically Important Fusarium spp.
Table 3. Genetic Identification Breakdown of the 58 Isolates and Comparison to the Reference Genotypic Classification for Medically Important Fusarium spp.
| Species Complex | Present Study n (%) | O’Donnell et al. 21 (%) |
| FSSC | 44 (75) | 62 |
| FOSC | 9 (16) | 29 |
| FIESC | 3 (5) | 2 |
| FDSC | 1 (2) | 1 |
| FCSC | — | — |
| GFSC | — | 6 |
| Unidentified | 1 (2) | — |
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