Changes in pneumococcal serotypes and antimicrobial resistance after introduction of the 13-valent conjugate vaccine in the United States

Ongoing surveillance for Streptococcus pneumoniae is needed to assess the impact of the pneumococcal conjugate vaccine introduced in 2010 (PCV13). Forty-two U.S. centers submitted S. pneumoniae isolates between 1 October 2012 and 31 March 2013. Susceptibility testing was performed by use of a broth dilution method as recommended by the Clinical and Laboratory Standards Institute. Serotyping was performed by multiplex PCR and the Quellung reaction. Multidrug resistance (MDR) was defined as nonsusceptibility to penicillin (PNSP; MIC ≥ 0.12 μg/ml) combined with resistance to ≥2 non-β-lactam antimicrobials. Penicillin-resistant S. pneumoniae (PRSP) was defined as a penicillin MIC of ≥2 μg/ml. For the 1,498 isolates collected during 2012-13, the PRSP and MDR rates were 14.2 and 21.0%, respectively. These percentages were lower than rates obtained in a surveillance study conducted 4 years earlier in 2008-09 (17.0 and 26.6%, respectively). The most common serotypes identified in 2012-13 were 3, 35B, and 19A, each representing 9 to 10% of all isolates. The largest percentage of PNSP in 2012-13 were found in serotypes 35B (24.8%), 19A (23.5%), and 15A (10.3%). Predominant PRSP serotypes were 19A (54.5%), 35B (28.2%), and 19F (7.0%). Major MDR serotypes were 19A (38.5%), 15A (16.9%), 6C (8.3%), and 35B (6.4%). The change in prevalence of PCV13 serotypes (43.4 to 27.1%) was primarily due to a decrease in serotype 19A strains, i.e., 22% of all strains in 2008-09 to 10% of all strains in 2012-13. Among the PNSP subset, serotypes showing a proportional increase were 35B, 15B, and 23B. Among MDR strains, the largest proportional increases were observed in serotypes 35B, 15B, and 23A.

Antibacterial properties of the CFTR potentiator ivacaftor

BACKGROUND

Ivacaftor increases CFTR channel activity and improves pulmonary function for individuals bearing a G551D mutation. Because ivacaftor structurally resembles quinolone antibiotics, we tested the hypothesis that ivacaftor possesses antibacterial properties.

METHODS

Bioluminescence, colony forming unit, and minimal inhibitory concentration assays were used to assess viability of Staphylococcus aureus, Pseudomonas aeruginosa and multiple clinical microbial isolates.

RESULTS

Ivacaftor induced a dose-dependent reduction in bioluminescence of S. aureus and decreased the number of colony forming units. We observed a similar but less robust effect in P. aeruginosa following outer membrane permeabilization. Ivacaftor inhibited the growth of respiratory isolates of S. aureus and Streptococcus pneumoniae and exhibited positive interactions with antibiotics against lab and respiratory strains of S. aureus and S. pneumoniae.

CONCLUSION

These data indicate that ivacaftor exhibits antibacterial properties and raise the intriguing possibility that ivacaftor might have an antibiotic effect in people with CF.

Methicillin-resistant Staphylococcus aureus prevention practices in hospitals throughout a rural state

BACKGROUND

The Institute for Healthcare Improvement (IHI) created an evidence-based bundle to help reduce methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections. The study aim was to identify which components of the IHI's MRSA bundle that rural hospitals have implemented and to identify barriers that hindered implementation of bundle components.

METHODS

Four surveys about the IHI's MRSA bundle were administered at the Iowa Statewide Infection Prevention Seminar between 2007 and 2011. Surveys were mailed to infection preventionists (IPs) who did not attend the meetings.

RESULTS

The percentage of IPs reporting that their hospital implemented a hand hygiene program (range by year, 87%-94%) and used contact precautions for patients infected (range by year, 97%-100%) or colonized (range by year, 77%-92%) with MRSA did not change significantly. The number of hospitals that monitored the effectiveness of environmental cleaning significantly increased from 23%-71% (P < .01). Few hospitals assessed daily if central lines were necessary (range by year, 22%-26%). IPs perceived lack of support to be a major barrier to implementing bundle components.

CONCLUSION

Most IPs reported that their hospitals had implemented most components of the MRSA bundle. Support within the health care system is essential for implementing each component of an evidence-based bundle.

Epidemiology and outcomes of invasive candidiasis due to non-albicans species of Candida in 2,496 patients: data from the Prospective Antifungal Therapy (PATH) registry 2004-2008

This analysis describes the epidemiology and outcomes of invasive candidiasis caused by non-albicans species of Candida in patients enrolled in the Prospective Antifungal Therapy Alliance (PATH Alliance) registry from 2004 to 2008. A total of 2,496 patients with non-albicans species of Candida isolates were identified. The identified species were C. glabrata (46.4%), C. parapsilosis (24.7%), C. tropicalis (13.9%), C. krusei (5.5%), C. lusitaniae (1.6%), C. dubliniensis (1.5%) and C. guilliermondii (0.4%); 111 infections involved two or more species of Candida (4.4%). Non-albicans species accounted for more than 50% of all cases of invasive candidiasis in 15 of the 24 sites (62.5%) that contributed more than one case to the survey. Among solid organ transplant recipients, patients with non-transplant surgery, and patients with solid tumors, the most prevalent non-albicans species was C. glabrata at 63.7%, 48.0%, and 53.8%, respectively. In 1,883 patients receiving antifungal therapy on day 3, fluconazole (30.5%) and echinocandins (47.5%) were the most frequently administered monotherapies. Among the 15 reported species, 90-day survival was highest for patients infected with either C. parapsilosis (70.7%) or C. lusitaniae (74.5%) and lowest for patients infected with an unknown species (46.7%) or two or more species (53.2%). In conclusion, this study expands the current knowledge of the epidemiology and outcomes of invasive candidiasis caused by non-albicans species of Candida in North America. The variability in species distribution in these centers underscores the importance of local epidemiology in guiding the selection of antifungal therapy.

Superantigens of Staphylococcus aureus from patients with diabetic foot ulcers

BACKGROUND

Diabetic foot ulcer (DFU) infections are challenging. Staphylococcus aureus is the most commonly isolated pathogen in DFUs. Superantigens (SAgs) are causative in many S. aureus infections. We hypothesized both that DFU S. aureus will produce large SAg numbers, consistent with skin infections, and that certain SAgs will be overrepresented. We assessed the SAg and α-toxin profile of isolates from patients with DFU, compared with profiles of isolates from other sources.

MATERIALS

Twenty-five S. aureus isolates from patients with DFU were characterized. Polymerase chain reaction was used to detect genes for methicillin-resistance and SAgs. Some SAgs and the α-toxin were quantified. We compared the SAg profile of DFU isolates with SAg profiles of S. aureus isolates from skin lesions of patients with atopic dermatitis and from vaginal mucosa of healthy individuals.

RESULTS

Most DFU isolates were methicillin susceptible (64%), with USA100 the most common clonal group. The SAg gene profile of DFU isolates most closely resembled that of isolates from patients with atopic dermatitis, with the highest number of different SAg genes per isolate and a high prevalence of staphylococcal enterotoxin D and the enterotoxin gene cluster. DFU isolates also had a high prevalence of staphylococcal enterotoxin-like X.

CONCLUSIONS

Comparison of the SAg profile of DFU isolates to SAg profiles of skin lesion isolates and vaginal mucosa isolates revealed that the SAg profile of DFU isolates was more similar to that of skin lesion isolates. SAgs offer selective advantages in facilitating DFU infections and suggest that therapies to neutralize or reduce SAg production by S. aureus may be beneficial in management of patients with DFU.

Effect of antibiotic stewardship programmes on Clostridium difficile incidence: a systematic review and meta-analysis

OBJECTIVES

Despite vigorous infection control measures, Clostridium difficile continues to cause significant disease burden. Antibiotic stewardship programmes (ASPs) may prevent C. difficile infections by limiting exposure to certain antibiotics. Our objective was to perform a meta-analysis of published studies to assess the effect of ASPs on the risk of C. difficile infection in hospitalized adult patients.

METHODS

Searches of PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature and two Cochrane databases were conducted to find all published studies on interventions related to antibiotic stewardship and C. difficile. Two investigators independently assessed study eligibility and extracted data. Risk of bias was assessed using the Downs and Black tool. Risk ratios were pooled using random effects models. Heterogeneity was evaluated using the I(2) statistic.

RESULTS

The final search yielded 891 articles; 78 full articles were reviewed and 16 articles were identified for inclusion. Included articles used quasi-experimental (interrupted time series or before-after) or observational (case-control) study designs. When the results of all studies were pooled in a random effects model, a significant protective effect (pooled risk ratio 0.48; 95% CI: 0.38, 0.62) was observed between ASPs and C. difficile incidence. When stratified by intervention type, a significant effect was found for restrictive ASPs (complete removal of drug or prior approval requirement). Furthermore, ASPs were particularly effective in geriatric settings.

CONCLUSIONS

Restrictive ASPs can be used to reduce the risk of C. difficile infection.

Continued emergence of USA300 methicillin-resistant Staphylococcus aureus in the United States: results from a nationwide surveillance study

BACKGROUND

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is changing, with USA300 emerging first in community and then in healthcare settings. We performed nationwide surveillance to assess recent trends in the molecular epidemiology of MRSA.

METHODS

One hundred consecutive unique clinically significant S. aureus isolates were recovered from patients at each of 43 US centers between July 1, 2011, and December 31, 2011. Susceptibility testing, pulsed-field gel electrophoresis (PFGE), staphylococcal protein A gene (spa) and staphylococcal cassette chromosome mec typing, and Panton-Valentine leukocidin detection were performed on all MRSA isolates.

RESULTS

Of 4,131 isolates collected, 2,093 (51%) were MRSA. Specimen sources of MRSA isolates included wound or abscess (54%), blood (24%), lower respiratory tract (11%), and other sterile site (10%). Thirty percent were isolated more than 48 hours after hospital admission (ie, were associated with nosocomial acquisition of infection). USA300 was the most common PFGE type (1,269 isolates; 61%), overall and in all regions, followed by USA100 (368 isolates; 18%). Among 173 spa types found, the most common were t008 (51%) and t002 (18%); no other spa type accounted for more than 2% of isolates. One strain type (USA300/t008/IV) constituted almost half of all MRSA isolates (1,005 isolates; 48%) and was the most common at all body sites, causing 37% of MRSA bloodstream infections (BSIs) and 38% of nosocomial MRSA infections. Multidrug-resistant phenotypes were found among 34 USA300 isolates (3%) from 18 states.

CONCLUSIONS

The USA300 PFGE type continues to advance nationwide. A single strain type (USA300/t008/IV) predominates in all regions and infection sites and is now more common than USA100 as a cause of MRSA BSI and nosocomial infections. Although most USA300 retain typical susceptibility profiles, multidrug-resistant phenotypes are emerging.

Concordance of nasal and diabetic foot ulcer staphylococcal colonization

Nasal carriage of Staphylococcus aureus (SA) is an important risk factor for surgical site infections. The goal of this study was to investigate the concordance between nasal and diabetic foot ulcer (DFU) SA carriage. Seventy-nine subjects with DFUs were assessed for nasal and DFU colonization with SA, including methicillin-resistant SA (MRSA). Twenty-five (31.6%) subjects had nares colonization with SA; 29 (36.7%) had DFU colonization with SA. Seven (8.8%) subjects had nares colonization with MRSA, and 7 (8.8%) had DFU colonization with MRSA. Ulcer duration was associated with MRSA presence (P = 0.01). Sensitivity and specificity of positive nasal SA colonization with positive DFU colonization were 41% and 74%. We found substantial discordance between SA strains colonizing DFU and the nasal cavity. The poor positive predictive values for SA isolation in a DFU based on nasal carriage suggests that SA colonization of a DFU by endogenous SA strains cannot be assumed.

Pneumococcal serotypes before and after introduction of conjugate vaccines, United States, 1999-2011(1.)

Serotyping data for pneumococci causing invasive and noninvasive disease in 2008-2009 and 2010-2011 from >43 US centers were compared with data from preconjugate vaccine (1999-2000) and postconjugate vaccine (2004-2005) periods. Prevalence of 7-valent pneumococcal conjugate vaccine serotypes decreased from 64% of invasive and 50% of noninvasive isolates in 1999-2000 to 3.8% and 4.2%, respectively, in 2010-2011. Increases in serotype 19A stopped after introduction of 13-valent pneumococcal vaccine (PCV13) in 2010. Prevalences of other predominant serotypes included in or related to PCV13 (3, 6C, 7F) also remained similar for 2008-2009 and 2010-2011. The only major serotype that increased from 2008-2009 to 2010-2011 was nonvaccine serotype 35B. These data show that introduction of the 7-valent vaccine has dramatically decreased prevalence of its serotypes and that addition of serotypes in PCV13 could provide coverage of 39% of isolates that continue to cause disease.

Use of micafungin as a surrogate marker to predict susceptibility and resistance to caspofungin among 3,764 clinical isolates of Candida by use of CLSI methods and interpretive criteria

Due to unacceptably high interlaboratory variation in caspofungin MIC values, we evaluated the use of micafungin as a surrogate marker to predict the susceptibility of Candida spp. to caspofungin using reference methods and species-specific interpretive criteria. The MIC results for 3,764 strains of Candida (eight species), including 73 strains with fks mutations, were used. Caspofungin MIC values and species-specific interpretive criteria were compared with those of micafungin to determine the percent categorical agreement (%CA) and very major error (VME), major error (ME), and minor error rates as well as their ability to detect fks mutant strains of Candida albicans (11 mutants), Candida tropicalis (4 mutants), Candida krusei (3 mutants), and Candida glabrata (55 mutants). Overall, the %CA was 98.8% (0.2% VMEs and MEs, 0.8% minor errors) using micafungin as the surrogate marker. Among the 60 isolates of C. albicans (9 isolates), C. tropicalis (5 isolates), C. krusei (2 isolates), and C. glabrata (44 isolates) that were nonsusceptible (either intermediate or resistant) to both caspofungin and micafungin, 54 (90.0%) contained a mutation in fks1 or fks2. An additional 10 C. glabrata mutants, two C. albicans mutants, and one mutant each of C. tropicalis and C. krusei were classified as susceptible to both antifungal agents. Using the epidemiological cutoff values (ECVs) of 0.12 μg/ml for caspofungin and 0.03 μg/ml for micafungin to differentiate wild-type (WT) from non-WT strains of C. glabrata, 80% of the C. glabrata mutants were non-WT for both agents (96% concordance). Micafungin may serve as an acceptable surrogate marker for the prediction of susceptibility and resistance of Candida to caspofungin.

Activities of vancomycin, ceftaroline, and mupirocin against Staphylococcus aureus isolates collected in a 2011 national surveillance study in the United States

Forty-two medical centers from throughout the United States participating in a longitudinal surveillance program were asked to submit 100 consecutive Staphylococcus aureus isolates during July to December 2011. Susceptibility testing using CLSI broth microdilution and mecA detection by PCR analysis was performed on the 4,131 isolates collected. Methods employing Etest glycopeptide resistance detection (GRD; bioMérieux) and brain heart infusion agar containing 4 μg/ml vancomycin (BHIV) were used to screen methicillin-resistant S. aureus (MRSA) isolates for heterogeneous intermediate-level resistance to vancomycin (hVISA). Isolates with positive hVISA screen results were confirmed by population analysis profiling-area under the curve (PAP-AUC) determinations. The genetic relatedness of hVISA, ceftaroline-nonsusceptible, or high-level (HL) mupirocin resistance MRSA isolates was assessed by pulsed-field gel electrophoresis (PFGE). Among 2,093 MRSA isolates, the hVISA screen results were positive with 47 isolates by Etest GRD and 30 isolates by BHIV agar screen. Twenty-five of the GRD- or BHIV screen-positive isolates were confirmed as hVISA by PAP-AUC testing. Results of the current study were compared to results obtained from prior surveillance performed in 2009. The prevalence of hVISA among MRSA isolates was higher in 2011 than in 2009 (1.2% versus 0.4%, P = 0.003), especially for isolates with a vancomycin MIC of 2 (45.4% versus 14.3%, P = 0.01). The overall rate of ceftaroline susceptibility in the current study was 99.4% (one hVISA isolate had an intermediate ceftaroline MIC). HL mupirocin resistance increased from 2.2% in 2009 to 3.2% in 2011 (P = 0.006). Although overall rates of hVISA and HL mupirocin resistance are low, they have increased since 2009.

Public reporting of health care-associated surveillance data: recommendations from the healthcare infection control practices advisory committee

Health care-associated infection (HAI) rates are used as measures of a health care facility's quality of patient care. Recently, these outcomes have been used to publicly rank quality efforts and determine facility reimbursement. The value of comparing HAI rates among health care facilities is limited by many factors inherent to HAI surveillance, and incentives that reward low HAI rates can lead to unintended consequences that can compromise medical care surveillance efforts, such as the use of clinical adjudication panels to veto events that meet HAI surveillance definitions.The Healthcare Infection Control Practices Advisory Committee, a federal advisory committee that provides advice and guidance to the Centers for Disease Control and Prevention (CDC) and the Secretary of the Department of Health and Human Services about strategies for surveillance, prevention, and control of HAIs, assessed the challenges associated with using HAI surveillance data for external quality reporting, including the unintended consequences of clinician veto and clinical adjudication panels. Discussions with stakeholder liaisons and committee members were then used to formulate recommended standards for the use of HAI surveillance data for external facility assessment to ensure valid comparisons and to provide as level a playing field as possible.The final recommendations advocate for consistent, objective, and independent application of CDC HAI definitions with concomitant validation of HAIs and surveillance processes. The use of clinician veto and adjudication is discouraged.

Seasonality of staphylococcal infections

Characterization of seasonal variation of Staphylococcus aureus is important in understanding the epidemiology of, and designing preventive strategies against this highly virulent and ever-evolving pathogen. In this review, we summarize the findings of epidemiological studies that have evaluated seasonality in S. aureus colonization and infection. Although most studies published to date are methodologically weak, some seasonal variation in the occurrence of S. aureus infection appears to exist, particularly an association of warm-weather months with S. aureus skin and soft-tissue infections. We highlight the limitations of the published literature, and provide suggestions for future studies on this topic.

Survey of high school athletic programs in Iowa regarding infections and infection prevention policies and practices

OBJECTIVE

To assess high school athletic programs' infection prevention policies and procedures and to estimate the frequency of skin and soft tissue infections (SSTIs) among Iowa's high school athletes.

METHODS

An on-line survey of high school athletic programs.

RESULTS

Nearly 60% of programs responded. Schools in higher classifications were more likely to have a certified athletic trainer (AT; P < 0.0001) and to report that they had a policy preventing athletes with SSTIs from participating in athletic events than were schools in lower classifications (P = 0.0002). Programs that had an AT reported that athletic training equipment (P = 0.01) and tables (P = 0.02) were cleaned more frequently than did programs without ATs. Programs were significantly more likely to provide training equipment than to provide soap or towels. About 57% of programs reported that at least one athlete acquired an SSTI during the prior school year, including methicillin- resistant Staphylococcus aureus (N = 14; 10.8%). Programs that had an AT (P = 0.02) were in higher classifications (P < 0.0001), educated athletes about SSTIs (P < 0.0001), or had policies regarding athletes with SSTIs (P = 0.01) were more likely than other programs to report having at least one athlete with an SSTI. The estimated SSTI rate per 1000 athletes ranged from 22.0 in 1A to 5.9 in 4A programs.

CONCLUSIONS

SSTIs are common among Iowa's high school athletes. Staff should review and update their infection prevention policies. Athletic programs need resources to support infection prevention efforts.

In vitro activity of ceftaroline against clinical isolates of Streptococcus pneumoniae recovered in 43 U.S. medical centers during 2010-2011

The in vitro activity of ceftaroline, a recently introduced parenteral cephalosporin, was assessed versus 1,750 isolates of Streptococcus pneumoniae recovered from patients with a variety of pneumococcal infections in 43 U.S. medical centers during 2010-2011. Using a breakpoint of ≤ 0.5 μg/ml for susceptibility, all of the isolates were found to be susceptible to ceftaroline. Ceftaroline MICs were consistently 16-fold lower than ceftriaxone MICs. Among the isolates characterized in this investigation, 38.9% were found to be nonsusceptible to penicillin (oral penicillin breakpoints) and 9.1% were nonsusceptible to ceftriaxone (nonmeningitis breakpoints).

Daptomycin exposure precedes infection and/or colonization with daptomycin non-susceptible enterococcus

Background

Daptomycin non-susceptible enterococci (DNSE) are emerging as an important cause of healthcare-associated infection, however little is known about the epidemiology of DNSE. At the University of Iowa Hospitals and Clinics (UIHC) an increase in the frequency of patients infected and/or colonized with DNSE has occurred. The goals of this study were to evaluate potential factors associated with the development of DNSE colonization and/or infection and to compare the characteristics of patients with prior daptomycin exposure to those without prior daptomycin exposure.

Methods

The study is a retrospective case-series involving all patients with DNSE infection and/or colonization at UIHC, a 734-bed academic referral center, from June 1, 2005 to June 1, 2011.

Results

The majority of patients with DNSE colonization and/or infection had prior daptomycin exposure (15 of 25; 60%), a concomitant gastrointestinal process (19 of 25; 76%), or were immunosuppressed (21 of 25; 84%). DNSE infection was confirmed in 17 of 25 (68%) patients, including 9 patients with bacteremia. Twelve of 17 (71%) patients with DNSE infection had prior daptomycin exposure, including 7 of 9 (78%) patients with bacteremia. Compared to patients without prior daptomycin exposure, patients with prior daptomycin exposure were less likely to harbor E. faecalis (0% vs. 33%; p = 0.019). A high proportion of patients (10 of 25; 40%) died during their hospitalizations. Most enterococcal isolates were E. faecium (86%), and were vancomycin-resistant (72%). Molecular typing revealed a diverse population of DNSE.

Conclusions

Prior daptomycin exposure, immunosuppression, and/or a concomitant gastrointestinal process, may be associated with the development of DNSE. PFGE revealed a diverse population of DNSE, which along with both increasing numbers of DNSE detected yearly and increasing annual rates of daptomycin usage, suggests the emergence of DNSE under antimicrobial pressure.

Prevalence, antibiotic resistance and molecular characterisation of Staphylococcus aureus in pigs at agricultural fairs in the USA

Fairs and petting zoos have been associated with outbreaks of zoonotic disease. Previously, the presence of meticillin-resistant Staphylococcus aureus (MRSA) was documented in commercial pigs; therefore, it was hypothesised that antibiotic-resistant S aureus may also occur in pigs exhibited at agricultural fairs. To test this hypothesis, 157 pigs were swabbed at two state fairs in 2008 to 2009. Both nares were sampled and cultures were grown in enrichment broth, then plated onto selective MRSA plates and blood plates. S aureus was confirmed using phenotypic and molecular methods, and was analysed using spa typing, gene-specific polymerase chain reaction and antibiotic susceptibility testing. The presence of S aureus was confirmed in samples collected from pigs exhibited at USA pig shows. Twenty-five of 157 (15.9 per cent) samples were positive for S aureus. Two isolates (8 per cent) were resistant to meticillin; 23/25 (92 per cent), 14/25 (56 per cent) and 15/25 (60 per cent) were resistant to tetracycline, erythromycin and clindamycin, respectively. spa typing revealed multiple isolates of spa type t034 (9/25, 36 per cent) and t337 (7/25, 28 per cent) and singletons of t002, t209, t526, t1236, t1334, t1683, t3075, t5784 and t5883. These results verify the presence of antibiotic-resistant S aureus in pigs exhibited at USA fairs, suggesting that pigs are a potential reservoir for S aureus within this environment.

Plasmid-borne vga(A)-encoding gene in methicillin-resistant Staphylococcus aureus ST398 recovered from swine and a swine farmer in the United States

We report a novel vga(A) detected in 3 methicillin-resistant Staphylococcus aureus ST398 recovered from swine and a swine caretaker in the United States. Strains were wild type for L3 and L4, but positive for vga(A) and tet(M). vga(A) was plasmid-located (ca. 24-kb) and demonstrated mobilization genes upstream and a transposase belonging to the IS3 family located downstream.

Activities of E1210 and comparator agents tested by CLSI and EUCAST broth microdilution methods against Fusarium and Scedosporium species identified using molecular methods

Fusarium (n = 67) and Scedosporium (n = 63) clinical isolates were tested by two reference broth microdilution (BMD) methods against a novel broad-spectrum (active against both yeasts and molds) antifungal, E1210, and comparator agents. E1210 inhibits the inositol acylation step in glycophosphatidylinositol (GPI) biosynthesis, resulting in defects in fungal cell wall biosynthesis. Five species complex organisms/species of Fusarium (4 isolates unspeciated) and 28 Scedosporium apiospermum, 7 Scedosporium aurantiacum, and 28 Scedosporium prolificans species were identified by molecular techniques. Comparator antifungal agents included anidulafungin, caspofungin, itraconazole, posaconazole, voriconazole, and amphotericin B. E1210 was highly active against all of the tested isolates, with minimum effective concentration (MEC)/MIC(90) values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, voriconazole, and amphotericin B, respectively, for Fusarium of 0.12, >16, >16, >8, >8, 8, and 4 μg/ml. E1210 was very potent against the Scedosporium spp. tested. The E1210 MEC(90) was 0.12 μg/ml for S. apiospermum, but 1 to >8 μg/ml for other tested agents. Against S. aurantiacum, the MEC(50) for E1210 was 0.06 μg/ml versus 0.5 to >8 μg/ml for the comparators. Against S. prolificans, the MEC(90) for E1210 was only 0.12 μg/ml, compared to >4 μg/ml for amphotericin B and >8 μg/ml for itraconazole, posaconazole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparator agents. The essential agreement (EA; ±2 doubling dilutions) was >93% for all comparisons, with the exception of posaconazole and F. oxysporum species complex (SC) (60%), posaconazole and S. aurantiacum (85.7%), and voriconazole and S. aurantiacum (85.7%). In conclusion, E1210 exhibited very potent and broad-spectrum antifungal activity against azole- and amphotericin B-resistant strains of Fusarium spp. and Scedosporium spp. Furthermore, in vitro susceptibility testing of E1210 against isolates of Fusarium and Scedosporium may be accomplished using either of the CLSI or EUCAST BMD methods, each producing very similar results.