Galleria mellonella Model of Coccidioidomycosis for Drug Susceptibility Tests and Virulence Factor Identification

Coccidioidomycosis (CM) can manifest as respiratory and disseminated diseases that are caused by dimorphic fungal pathogens, such as Coccidioides species. The inhaled arthroconidia generated during the saprobic growth phase convert into multinucleated spherules in the lungs to complete the parasitic lifecycle. Research on coccidioidal virulence and pathogenesis primarily employs murine models typically associated with low lethal doses (LD100 < 100 spores). However, the Galleria model has recently garnered attention due to its immune system bearing both structural and functional similarities to the innate system of mammals. Our findings indicate that Coccidioides posadasii can convert and complete the parasitic cycle within the hemocoel of the Galleria larva. In Galleria, the LD100 is between 0.5 and 1.0 × 106 viable spores for the clinical isolate Coccidioides posadasii C735. Furthermore, we demonstrated the suitability of this model for in vivo antifungal susceptibility tests to validate the bioreactivity of newly discovered antifungals against Coccidioides. Additionally, we utilized this larva model to screen a Coccidioides posadasii mutant library showing attenuated virulence. Similarly, the identified attenuated coccidioidal mutants displayed a loss of virulence in a commonly used murine model of coccidioidomycosis. In this study, we demonstrated that Galleria larvae can be applied as a model for studying Coccidioides infection.

Epidemiology of Coccidioidomycosis in the Veterans Health Administration, 2013-2022

We describe the epidemiology of coccidioidomycosis among a national cohort of Veterans. Using electronic health record data from adults tested for coccidioidomycosis between 1 January 2013 and 31 December 2022, we analyzed differences in baseline demographics (age, sex, race/ethnicity, birth country, comorbidities, residence, and Charlson Comorbidity Index score) between 4204 coccidioidomycosis-test-positive and 63,322 test-negative Veterans. Log-binomial regression models with adjusted risk ratios (aRRs) were used to evaluate risk factors associated with coccidioidomycosis including dissemination, hospitalization, and mortality. Case counts and incidence rates were highest in select counties in Arizona and California where Coccidioides is endemic. Coccidioidomycosis-positive Veterans were younger, more likely to be male, and Philippine-born. The risk factors most highly associated with being coccidioidomycosis-positive included Native Hawaiian/Pacific Islander (aRR 1.068 [95%CI: 1.039-1.098]), Asian (aRR 1.060 [95%CI: 1.037-1.083]), Black (aRR 1.029 [95%CI: 1.022-1.036]), American Indian/Alaska Native (aRR 1.026 [95%CI: 1.004-1.048]) race, and Hispanic/Latino ethnicity (aRR 1.021 [95%CI: 1.013-1.028]). Black race (aRR: 1.058 [95%CI: 1.037-1.081]) and Hispanic/Latino ethnicity (aRR 1.018 [95%CI: 1.0003-1.036]) were also associated with disseminated coccidioidomycosis, strengthening the evidence for the association of coccidioidomycosis, including severe infections, with specific racial and ethnic groups. There were no statistically significant differences in hospitalization within 45 days of testing or 30-day all-cause mortality. Improving our understanding of coccidioidomycosis risk factors is important for targeted prevention strategies and to reduce delays in diagnosis and ineffective treatment.

Controversies in the Management of Central Nervous System Coccidioidomycosis

Central nervous system infection with Coccidioides spp is fatal if untreated, and complications occur even when therapy is directed by experienced clinicians. We convened a panel of clinicians experienced in the management of coccidioidal meningitis to summarize current controversies and provide consensus for the management of this difficult infection.

Demonstration of N,N-Dimethyldithiocarbamate as a Copper-Dependent Antibiotic against Multiple Upper Respiratory Tract Pathogens

Transition metals are necessary cofactors and structural elements in living systems. Exposure to high concentrations of biologically important transition metals, such as zinc and copper, results in cell toxicity. At the infection site, the immune system deploys metal sorbent proteins (e.g., lactoferrin and calprotectin) to starve pathogens of necessary metals (such as iron), while phagocytes expose engulfed pathogens to high levels of other metals, such as copper and zinc. The opportunistic pathogen Streptococcus pneumoniae (the pneumococcus) encounters macrophages during initial and protracted infections. The pneumococcus employs a copper export pathway, which improves colonization and persistent infection of the nasopharynx and the upper respiratory tract. Because copper is tightly regulated in the host, we instead sought to leverage the localized power of nutritional immunity by identifying small molecules with copper-dependent toxicity (CDT) through a targeted screen of compounds for antibiotic efficacy. We chose to include dithiocarbamates, based on the copper synergy observed in other organisms with 1-(diethylthiocarbamoyldisulfanyl)-N,N-diethyl-methanethioamide (tetraethylthiuram disulfide, disulfiram). We observed CDT of some dithiocarbamates in S. pneumoniae. Only N,N-dimethyldithiocarbamate (DMDC) was consistently toxic across a range of concentrations with copper both in vitro and in vivo against the pneumococcus. We also observed various degrees of CDT in vitro using DMDC in Staphylococcus aureus, Coccidioides posadasii, and Schistosoma mansoni. Collectively, we demonstrate that the compound DMDC is a potent bactericidal compound against S. pneumoniae with antimicrobial efficacy against bacterial and fungal pathogens.

IMPORTANCE With the rise of antibiotic resistance, approaches that add new antimicrobials to the current repertoire are vital. Here, we investigate putative and known copper ionophores in an attempt to intoxicate bacteria and use ionophore/copper synergy, and we ultimately find success with N,N-dimethyldithiocarbamate (DMDC). We show that DMDC has in vitro efficacy in a copper-dependent manner and kills pathogens across three different kingdoms, Streptococcus pneumoniae, Coccidioides posadasii, and Schistosoma mansoni, and in vivo efficacy against S. pneumoniae. As such, dithiocarbamates represent a new potential class of antimicrobials and thus warrant further mechanistic investigation.

Knowledge, attitudes, and practices regarding coccidioidomycosis among healthcare providers in four counties in Washington State, 2017

Coccidioidomycosis is an emerging infection in Washington State. The epidemiology of the disease in Washington is poorly understood at present; underrecognition and underreporting of coccidioidomycosis is suspected based on reports of only severe disease. We sought to characterize healthcare provider knowledge, attitudes, and practices regarding coccidioidomycosis awareness, diagnosis, and treatment in south-central Washington. We conducted a cross-sectional survey of actively practicing healthcare providers in four counties in south-central Washington, an area recently described as endemic for Coccidioides. Survey results were used to assess awareness of reporting requirements, confidence in ability to diagnose and treat, confidence that knowledge is current, calculated knowledge score, and consideration of risk in patient population. The majority of respondents were unaware of the reporting requirement for coccidioidomycosis in Washington and further unaware that the disease had been reported in the state. Less than a third of survey respondents reported confidence in their ability to diagnose coccidioidomycosis and confidence that their knowledge is current. The majority of respondents never or rarely consider a diagnosis of coccidioidomycosis, and <25% of respondents indicated a working knowledge of serologic tests for the infection. The average knowledge score for respondents was 65%. Previous education, training, or practice regarding coccidioidomycosis was the only identified predictor of confidence and consideration of risk. These data indicate the substantial need for education and training among healthcare providers in south-central Washington and support the concern that a small proportion of existing cases of coccidioidomycosis are reported to the health department.

Unifying atmospheric biology research for the U.S. scientific community

A global COVID-19 pandemic, rising asthma and allergies, along with climate change impacting storm intensity and frequency, point to an urgent need to unify U.S. atmospheric biology research. To this end, we briefly define atmospheric biology, summarize its fragmented history, and then outline how to unify the field to provide benefits for the U.S. science community and its citizens. Atmospheric biology refers to the study of concentrations, sources, sinks, transformation, and impacts of airborne microorganisms inclusive of pollen, fungal spores, algae, lichens, bacteria, viruses, cellulose fibers, and other biomolecules or fragments of cells. Here our focus is biological particles, both respirable (PM₁₀ ) and systemic (PM_2.5 ). Due to its interdisciplinary dependencies and broadness of scales from nanometers to kilometers, atmospheric biology research is highly fragmented in the U.S. science community. It lacks shared paradigms and common vocabulary. This deficit calls for recognizing atmospheric biology as a research community in its own right, thereby linking human health to climate change. We need to recognize atmospheric biology's importance to national security and science diplomacy. Advanced atmospheric biology research is being conducted in Europe, Russia, and China, not in the United States.

Laser Capture Microdissection-Assisted Protein Biomarker Discovery from Coccidioides-Infected Lung Tissue

Laser capture microdissection (LCM) coupled to label-free quantitative mass spectrometry is a viable strategy to identify biomarkers from infected tissues. In this study, LCM was employed to take a “snapshot” of proteins produced in vivo during Coccidiodies spp. infection in human lungs. Proteomic analysis of LCM lung sections revealed hundreds of hosts and Coccidioidal proteins. Twenty-seven highly abundant Coccidioides spp. proteins were identified which do not share significant sequence orthology with human proteins. Three of the 27 Coccidioidal proteins are also potential Coccidoides-specific biomarkers, as they also do not share sequence homology to any other pathogenic fungus or microbe. Gene ontology analysis of the 27 biomarker candidate proteins revealed enriched hydrolase activity and increased purine and carbohydrate metabolism functions. Finally, we provide proteomic evidence that all 27 biomarker candidates are produced by the fungus when grown in vitro in a media- and growth-phase dependent manner.

Carbo-loading in Coccidioides spp.: A quantitative analysis of CAZyme abundance and resulting glycan populations

Coccidioides spp. are important pneumonia-causing pathogens of the American southwest, but little is known about their glycobiology and how their glycosylations differ from other pneumonia-causing fungi. There is mounting preliminary evidence to suggest genus or even species-specific glycosylations in the fungal kingdom due to the presence of unique carbohydrate-active enzymes (CAZymes) in fungal genomes (Deshpande et al. 2008, Glycobiology, 18(8), 626-637; Karkowska-Kuleta and Kozik 2015, Acta Biochim Pol., 62(3), 339-351). If Coccidioides spp.-specific glycans can be identified, it may be possible to exploit these differences to develop more specific diagnostic approaches and more effective therapeutics. Herein, we i) mined Coccidioides spp. and other pathogenic fungal genomes to identify CAZymes specific for Coccidioides spp., ii) proteomically determined the Coccidioides spp. "CAZome" produced in vivo and in vitro, and iii) utilized glycomics to differentiate Coccidioides genus-specific N-glycans from other pathogenic fungi. As far as we are aware, this is the first proteomic and glycomic comparison of the N-glycomes and CAZomes of different fungal genera during infection in human hosts.

Coccidioidomycosis in llamas and alpacas diagnosed at the University of California, Davis (1990-2016)

Given the predisposition of South American camelids to coccidioidomycosis, we sought to describe the disease presentation in alpacas and llamas and identify potential risk factors for these species. The records of 224 llamas and alpacas that were tested for Coccidioides infection using immunodiffusion serology at the Coccidioidomycosis Serology Laboratory of the University of California, Davis, between 1990 and 2016 were examined; of those, 46 alpacas and 42 llamas had positive test results. The remaining 99 alpacas and 37 llamas were used as control groups. We found that male llamas were at increased risk for Coccidioides infection when compared with female llamas and when compared with male alpacas. South American camelids living within California were at higher risk for infection than camelids living in other states. Alpacas were more likely than llamas to have subclinical infections. We documented five cases of abortion or neonatal mortality attributable to coccidioidomycosis in alpacas. Our study demonstrates that South American camelids are susceptible to Coccidioides infection in areas where the disease is endemic, lending support to the importance of vigilance for this disease in alpacas and llamas and suggesting a possible role for these animals as sentinel species.

LAY SUMMARY

We examined cases of Valley Fever and described the disease and risk factors for llamas and alpacas. Male llamas were at increased risk for infection as were animals living within California. Five alpacas had miscarriages or neonatal deaths as a result of Valley Fever infections.

Bicavitary eosinophilic effusion in a dog with coccidioidomycosis

This is a case of coccidioidomycosis in a dog, examined for vomiting and labored breathing. Physical examination and thoracic and abdominal imaging revealed pleural and peritoneal effusions, both of which exhibited neutrophilic inflammation with a substantial eosinophilic component. The dog had positive IgM and IgG coccidioidomycosis titers at initial evaluation. The eosinophilic component of the inflammation was attributed to coccidioidomycosis. The dog underwent approximately 6 months of fluconazole treatment, with both effusions and clinical signs improving after 6 weeks. Three months after cessation of antifungal treatment, the dog developed a mid‐diaphyseal lytic and proliferative lesion in the left radius caused by Coccidioides spp. This case illustrates the importance of consideration of coccidioidomycosis when an eosinophilic cavitary effusion is present in dogs that live in or have traveled to endemic regions.

Risk factors and outcomes of culture-proven acute Coccidioides spp. infection in San Diego, California, United States

BACKGROUND

Coccidioides spp. are dimorphic fungi endemic to parts of the United States, Mexico, Central and South America. Infection can cause a range of disease from self-limited acute pneumonia to severe disseminated disease.

METHODS

We performed a retrospective chart review of medical records of cases of culture-proven acute coccidioidomycosis at the University of California San Diego between 1 April 2015 and 31 December 2019 and described the demographics, risk factors and outcomes of these cases.

RESULTS

Over the study period, fifteen evaluable cases of culture-proven acute coccidioidomycosis were identified. Of these, 87% (13/15) had traditional risk factors for coccidioidomycosis infection while two lacked known risk factors, including one patient with cirrhosis and one with chronic hepatitis C infection. Seven of fifteen (47%) had primary coccidioidomycosis of the lungs without dissemination and 7/15 (47%) disseminated disease. Of those with disseminated disease, 6/7 (86%) had either high-risk ethnicity or blood type as their only risk factor. At 90 days, 11/15 (73%) were alive, 3/15 (20%) deceased and 1/15 (7%) lost to follow-up. Of those not alive at 90 days, 1/3 (33%) had disseminated disease and 2/3 (67%) primary coccidioidomycosis, both on immunosuppressive therapy.

DISCUSSION

Coccidioides spp. infection occurs in a variety of hosts with varying underlying risk factors, with the majority in our cohort overall and 86% with disseminated disease lacking traditional risk factors for invasive fungal infection other than ethnicity and/or blood phenotype. Clinicians should be aware of these non-traditional risk factors in patients with coccidioidomycosis infection.

Population Structure and Genetic Diversity among Isolates of Coccidioides posadasii in Venezuela and Surrounding Regions

Coccidioides posadasii is a pathogenic fungus that causes coccidioidomycosis in many arid regions of the Americas. One of these regions is bordered by the Caribbean Sea, and the surrounding landscape may play an important role in the dispersion of C. posadasii across South America through southeastern Mexico, Honduras, Guatemala, and Venezuela. Comparative phylogenomic analyses of C. posadasii reveal that clinical strains from Venezuela are genetically distinct from the North American populations found in (i) Arizona and (ii) Texas, Mexico, and the rest of South America (TX/MX/SA). We find evidence for admixture between the Venezuela and the North American populations of C. posadasii in Central America. Additionally, the proportion of Venezuelan alleles in the admixed population decreases as latitude (and distance from Venezuela) increases. Our results indicate that the population in Venezuela may have been subjected to a recent bottleneck and shows a strong population structure. This analysis provides insight into potential for Coccidioides spp. to invade new regions.IMPORTANCE Valley Fever is a fungal disease caused by two species of fungi: Coccidioides immitis and C. posadasii These fungi are found throughout the arid regions of North and South America; however, our understanding of genetic diversity and disease in South America is limited. In this report, we analyze 10 new genomes of Coccidioides posadasii from regions bordering the Caribbean Sea. We show that these populations are distinct and that isolates from Venezuela are likely a result of a recent bottleneck. These data point to patterns that might be observed when investigating recently established populations.

Communicating Risk for a Climate-Sensitive Disease: A Case Study of Valley Fever in Central California

Valley Fever, or Coccidioidomycosis, a fungal respiratory disease, is prevalent with increasing incidence in the Southwestern United States, especially in the central region of California. Public health agencies in the region do not have a consistent strategy for communication and health promotion targeting vulnerable communities about this climate-sensitive disease. We used the behavior adaptation communication model to design and conduct semi-structured interviews with representatives of public health agencies in five California counties: Fresno, Kern, Kings, San Luis Obispo, and Tulare County. While none of the agencies currently include climate change information into their Valley Fever risk messaging, the agencies discuss future communication methods similar to other health risk factors such as poor air quality days and influenza virus season. For political reasons, some public health agencies deliberately avoided the use of climate change language in communicating health risk factors to farmers who are particularly vulnerable to soil and dust-borne fungal spores. The effectiveness of health communication activities of the public health agencies has not been measured in reducing the prevalence of Valley Fever in impacted communities. Given the transboundary nature of climate influence on Valley Fever risk, a concerted and consistent health communication strategy is expected to be more effective than current practices.

Soil and climactic predictors of canine coccidioidomycosis seroprevalence in Washington State: An ecological cross-sectional study

Coccidioidomycosis is a predominantly respiratory infection of animals and humans caused by soil-dwelling fungi. Long known to be endemic to North American deserts, locally acquired human cases first emerged in Washington State in 2010. To inform development of an environmental niche map, we conducted an ecological cross-sectional study of the association between soil and climactic variables and canine seroprevalence in Washington State, at the zip code tabulation area level. Soil predictors included soil texture (per cent sand, silt and clay), pH, electrical conductivity and water storage capacity; climactic predictors included mean annual air temperature and liquid precipitation. Clustering was evaluated with Moran's I, and four modelling approaches were adopted a priori: two models without any smoothing (logistic regression and quasi-logistic regression) and two smoothing models (non-spatial and spatial smoothing). No evidence was found for clustering, and both smoothing models resulted in marked attenuation of all coefficients. Temperature was found to have a positive effect in the non-smoothing models (prevalence odds ratio, logistic model: 1.70, 95% confidence interval 1.02, 2.84). While no other significant associations were found, there was suggestive evidence of a positive effect for pH. Despite the limitations inherent to the ecological and cross-sectional nature of these data, these findings provide insight for the development of an environmental niche map in Washington State and demonstrate the utility of using data from an animal sentinel to predict human disease risk.

First Analysis of Human Coccidioides Isolates from New Mexico and the Southwest Four Corners Region: Implications for the Distributions of C. posadasii and C. immitis and Human Groups at Risk

Coccidioidomycosis (Valley Fever) is a disease caused by species of Coccidioides. The disease is endemic to arid regions of the Southwestern US and while most common in CA and AZ is also present in NM. We present the first genetic analysis of clinical isolates from NM. Travel and demographic information was available for a number of patients, which included individuals from NM and the Southwestern US Four Corners region. Multi-gene phylogenetic analyses revealed the presence of both C. posadasii and C. immitis. While NM is predicted to be within the endemic range for C. posadasii, our results expand the known range of C. immitis, often considered to be the "California species". Five of eight infections for which patient ethnicity existed occurred in Native Americans, and two occurred in African Americans. Several isolates came from the northwestern part of NM-outside the predicted "highly-endemic" region. Our study suggests Native Americans represent an unrecognized at-risk group, and it provides a foundation for better defining the geographic distribution of the Coccidioides species and for preventing exposure among populations at risk. In the course of this study, we developed a reliable PCR-based method to distinguish species targeting regions of the mitochondrial genome.

Comparison of two FDA-cleared EIA assays for the detection of Coccidioides antibodies against a composite clinical standard

Coccidioidomycosis is a disease endemic to the southwestern United States, parts of Mexico, and Central and South America. Diagnosis of the disease is commonly delayed because of the lack of prompt testing and the dearth of reliable diagnostic tests. Culture and nucleic acid testing require a specimen, yet the typical patient presents with a dry cough and no sputum. Serologic methods depend on an effective antibody response by the patient, but antibody production may be unreliable or delayed until several weeks after initial symptom onset. Most published reports of serologic assays compare them to traditional serologic tests such as complement fixation and immunodiffusion. We sought to characterize the performance of two commercially available serologic tests, Meridian Premier and IMMY Omega, against a composite clinical reference standard to determine the sensitivity and specificity of these tests in detecting whether antibody is likely present in clinical specimens. The composite reference standard included symptoms, radiologic findings, and serologic results from complement fixation and immunodiffusion. For the Meridian test, sensitivity and specificity respectively were 69.4% and 95.4% for immunoglobulin G (Ig G) and 57.1% and 70.4% for immunoglobulin M (IgM). For the IMMY assay, sensitivity and specificity respectively were 53.1% and 96.7% for IgG and 34.7% and 85.5% for IgM.

Valley Fever on the Rise-Searching for Microbial Antagonists to the Fungal Pathogen Coccidioides immitis

The incidence of coccidioidomycosis, also known as Valley Fever, is increasing in the Southwestern United States and Mexico. Despite considerable efforts, a vaccine to protect humans from this disease is not forthcoming. The aim of this project was to isolate and phylogenetically compare bacterial species that could serve as biocontrol candidates to suppress the growth of Coccidioides immitis, the causative agent of coccidioidomycosis, in eroded soils or in areas close to human settlements that are being developed. Soil erosion in Coccidioides endemic areas is leading to substantial emissions of fugitive dust that can contain arthroconidia of the pathogen and thus it is becoming a health hazard. Natural microbial antagonists to C. immitis, that are adapted to arid desert soils could be used for biocontrol attempts to suppress the growth of the pathogen in situ to reduce the risk for humans and animals of contracting coccidioidomycosis. Bacteria were isolated from soil samples obtained near Bakersfield, California. Subsequently, pairwise challenge assays with bacterial pure cultures were initially performed against Uncinocarpus reesii, a non-pathogenic relative of C. immitis on media plates. Bacterial isolates that exhibited strongly antifungal properties were then re-challenged against C. immitis. Strongly anti-C. immitis bacterial isolates related to Bacillus subtilis and Streptomyces spp. were isolated, and their antifungal spectrum was investigated using a selection of environmental fungi.

A novel form of intracranial coccidioidomycosis is present in dogs and exhibits characteristic clinical and magnetic resonance imaging findings

The neurological examination findings, clinical pathology (including Coccidioides immitis IgG/IgM serology) and magnetic resonance imaging (MRI) findings in 13 dogs with a novel form of intracranial coccidioidomycosis are described in a retrospective case series, with long-term clinical resolution documented in 11/13 dogs (84.6% of cases) with oral fluconazole therapy. The medical records of the Veterinary Neurological Center in Phoenix, Arizona from the years 2000 to 2017 were utilized to search for dogs with appropriate inclusion criteria. Magnetic resonance imaging findings were highly consistent across all cases and characteristically demonstrated bilaterally symmetric T2 hyperintensity throughout the frontal lobes, caudate nuclei, and rostral internal capsule, ±faint, wispy contrast enhancement on T1-postcontrast images. These findings were in stark contrast to previously reported MRI findings in dogs with intracranial coccidioidomycosis, which were typically characterized by a focal, strongly contrast enhancing granuloma and extensive vasogenic edema, typically unilateral. Schnauzer breeds represented eight of 13 (61.5%) cases, possibly suggesting a breed predilection. Three cases underwent repeat MRI after resolution of neurological signs and documentation of a decreased Coccidioides titer in response to fluconazole therapy. All demonstrated complete resolution of previously identified lesions, but with marked, severe atrophy of the caudate nuclei and frontal lobes bilaterally. Findings from this study document a variant appearance for intracranial coccidioidomycosis that, to the author's knowledge, has not been previously described in dogs. Authors propose that, although this variant demonstrates extensive pathological changes within the forebrain, the clinical outcome and response to treatment is favorable in a majority of cases.

Risk Stratification With Coccidioidal Skin Test to Prevent Valley Fever Among Inmates, California, 2015

Two California state prisons (A and B) have very high rates of coccidioidomycosis (Valley Fever). The prison health care service sought to improve their prevention strategy by risk stratification with a newly available spherulin-based Coccidioides delayed-type hypersensitivity test. Of the 36,789 voluntarily screened inmates, 4.7% experienced adverse reactions. A positive test (8.6% of those tested) was independently associated with (1) incarceration at prisons A and B, (2) admission to prison from a Coccidioides-endemic county, (3) length of stay at prisons A and B, and (4) increasing age. These findings suggest that the test is safe and performing well at risk stratification; the prison system now restricts inmates with negative tests from prisons A and B. This novel use of the test might benefit other coccidioidomycosis prevention programs.

Effective Disinfectants for Coccidioides immitis and C. posadasii

The lack of published data on effective disinfectants and contact times for use on the fungal pathogens Coccidioides immitis and C. posadasii prompted the authors to investigate the fungicidal activity of three commonly used laboratory disinfectants on arthroconidia harvested from C. immitis strain 2009. They tested the ability of 10% bleach, 70% ethanol, and Vesphene^® IIse to inactivate 10⁷ arthroconidia in an aqueous suspension within 1, 2, 5, 10, or 20 minutes of contact time. Both 10% bleach and 70% ethanol provided a 7-log¹⁰ reduction in arthroconidia in less than 1 minute, with no growth observed at any of the tested time points. Vesphene^® IIse was less effective, providing a 6-log¹⁰ reduction in arthroconidia after 5 minutes, but was unable to completely inactivate all of the arthroconidia, even after 20 minutes of contact time.