Two-Dimensional Regulation of CAR-T Cell Therapy with Orthogonal Switches

Use of chimeric antigen receptors (CARs) as the basis of targeted adoptive T cell therapies has enabled dramatic efficacy against multiple hematopoietic malignancies, but potency against bulky and solid tumors has lagged, potentially due to insufficient CAR-T cell expansion and persistence. To improve CAR-T cell efficacy, we utilized a potent activation switch based on rimiducid-inducible MyD88 and CD40 (iMC)-signaling elements. To offset potential toxicity risks by this enhanced CAR, an orthogonally regulated, rapamycin-induced, caspase-9-based safety switch (iRC9) was developed to allow in vivo elimination of CAR-T cells. iMC costimulation induced by systemic rimiducid administration enhanced CAR-T cell proliferation, cytokine secretion, and antitumor efficacy in both in vitro assays and xenograft tumor models. Conversely, rapamycin-mediated iRC9 dimerization rapidly induced apoptosis in a dose-dependent fashion as an approach to mitigate therapy-related toxicity. This novel, regulatable dual-switch system may promote greater CAR-T cell expansion and prolonged persistence in a drug-dependent manner while providing a safety switch to mitigate toxicity concerns.

Abstract LB-184: Dual-switchGoCAR-T cells: small molecule-regulated “GO” and “STOP” switches to target solid cancer in vivo

Background:

While chimeric antigen receptor (CAR)-T immunotherapies have shown remarkable efficacy against leukemias and lymphomas, improved CAR-T efficacy and persistence are needed to overcome solid tumors, without compromising safety. Here, we present two independently regulated molecular switches that can elicit specific and rapid induction of cellular responses upon exposure to their cognate ligands. Cell activation is controlled by the homodimerizer rimiducid that triggers signaling cascades downstream of MyD88 and CD40 via an engineered chimeric protein termed iMC. A rapamycin-controlled pro-apoptotic switch, iRC9, is co-expressed, which induces dimerization of the caspase-9 domain to mitigate possible toxicity from excessive CAR-T function. When combined with a first generation CAR, these molecular switches allow for specific and efficient regulation of engineered T cells.

Methods & Results:

T cells were activated and co-transduced with the HER2 GoCAR (SFG-iMC.2A-CAR.ζ) and RapaCIDe (SFG-iRC9.2A-ΔCD19) vectors to generate “Dual-switch GoCAR-T” cells. Combined transduction of RapaCIDe and HER2 GoCAR vectors into T cells did not adversely affect the antitumor efficacy of the GoCAR-T cells, which eliminated OE19 esophageal tumor cells in a 7-day coculture assay at a 1:20 effector to target ratio (3.9±4.3% OE19-eGFPFluc cells remained in GoCAR-modified cultures vs. 1.1±0.1% for the dual-switch GoCAR), and promoted T cell expansion (53.4±9.4% CAR+ for GoCAR vs. 44.6±13.2% for the dual-switch). When challenged in an OE19 tumor-bearing mouse model, rimiducid stimulation of the dual-switch GoCAR-T cells enhanced tumor killing and T cell expansion.

Deployment of the off-switch induced fast (½ Vmax ~ 8 hours) and efficient elimination of T cells (Dual-switch GoCAR-T = 94.1% AnnV+/PI+ vs. GoCAR-T = 5.1%) in a caspase-3 activation assay with real-time (IncuCyte) monitoring as well as AnnV/PI detection by flow cytometry. In vivo assessment of the RapaCIDe switch was performed via eGFPluciferase (eGFPfluc)-labeled RapaCIDe-T cells in NSG mice. Rapamycin, but not rimiducid, treatment efficiently eliminated RapaCIDe-T cells within 24 hours, which is similar to the rate observed by the clinically validated rimiducid-regulated CaspaCIDe switch.

Summary:

Dual-switch GoCAR-T, a novel platform comprising a first-generation CAR combined with regulated costimulation and apoptotic signaling elements, effectively controlled tumor growth and T cell expansion and elimination in vitro and in vivo. This dual-switch technology provides a user-controlled system for managing persistence and safety of tumor antigen-specific CAR-T cells.

Citation Format: MyLinh T. Duong, Matthew R. Collinson-Pautz, Eva Morschl, Mary E. Brandt, Ming Zhang, Kevin W. Slawin, Aaron E. Foster, J. Henri Bayle, David M. Spencer. Dual-switchGoCAR-T cells: small molecule-regulated “GO” and “STOP” switches to target solid cancer in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-184. doi:10.1158/1538-7445.AM2017-LB-184

Clinical and Laboratory Profile of Persons Living with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome and Histoplasmosis from a Colombian Hospital

Histoplasmosis is common among persons living with human immunodeficiency virus/acquired immune deficiency syndrome (PLWHA) in Latin America, but its diagnosis is difficult and often nonspecific. We conducted prospective screening for histoplasmosis among PLWHA with signs or symptoms suggesting progressive disseminated histoplasmosis (PDH) and hospitalized in Hospital La María in Medellín, Colombia. The study's aim was to obtain a clinical and laboratory profile of PLWHA with PDH. During 3 years (May 2008 to August 2011), we identified 89 PLWHA hospitalized with symptoms suggestive of PDH, of whom 45 (51%) had histoplasmosis. We observed tuberculosis (TB) coinfection in a large proportion of patients with PDH (35%), so all analyses were performed adjusting for this coinfection and, alternatively, excluding histoplasmosis patients with TB. Results showed that the patients with PDH were more likely to have Karnofsky score ≤ 30 (prevalence ratio [PR] = 1.98, 95% confidence interval [CI] = 0.97-4.06), liver compromised with hepatomegaly and/or splenomegaly (PR = 1.77, CI = 1.03-3.06) and elevation in serum of alanine aminotransferase and aspartate aminotransferase to values > 40 mU/mL (PR = 2.06, CI = 1.09-3.88 and PR = 1.53, CI = 0.99-2.35, respectively). Using multiple correspondence analyses, we identified in patients with PDH a profile characterized by the presence of constitutional symptoms, namely weight loss and Karnofsky classification ≤ 30, gastrointestinal manifestations with alteration of liver enzymes and hepatosplenomegaly and/or splenomegaly, skin lesions, and hematological alterations. Study of the profiles is no substitute for laboratory diagnostics, but identifying clinical and laboratory indicators of PLWHA with PDH should allow development of strategies for reducing the time to diagnosis and thus mortality caused by Histoplasma capsulatum.

Judgment of Emotion

Thirty American subjects accurately identified emotions from 96 situations which American and Malay informants stated to be antecedent to specific emotions. These results are considered in terms of the proposition that the underlying meanings of antecedent events are the stimuli for the experience of emotion, and that these meanings can be inferred across cultural boundaries.

Outbreak of Bloodstream Infection With the Mold Phialemonium Among Patients Receiving Dialysis at a Hemodialysis Unit

Background

Molds are a rare cause of disseminated infection among dialysis patients.

Objective.

We evaluated a cluster of intravascular infections with the mold Phialemonium among patients receiving hemodialysis at the same facility in order to identify possible environmental sources and prevent further infection.

Design.

Environmental assessment and case-control study.

Setting.

A hemodialysis center affiliated with a tertiary care hospital.

Methods.

We reviewed surveillance and clinical microbiology records and performed a blood culture survey for all patients. The following data for case patients were compared with those for control patients: underlying illness, dialysis characteristics, medications, and other possible exposure for 120 days prior to infection. Environmental assessment of water treatment, dialysis facilities, and heating, ventilation, and air-conditioning (HVAC) systems of the current and previous locations of the dialysis center was performed. Samples were cultured for fungus; Phialemonium isolates were confirmed by sequencing of DNA. Investigators observed dialysis access site disinfection technique.

Results.

Four patients were confirmed as case patients, defined as a patient having intravascular infection with Phialemonium species; 3 presented with fungemia, and 1 presented with an intravascular graft infection. All case patients used a fistula or graft for dialysis access, as did 12 (75%) of 16 of control patients (P = .54). Case and control patients did not differ in other dialysis characteristics, medications received, physiologic findings, or demographic factors. Phialemonium species were not recovered from samples of water or dialysis machines, but were recovered from the condensation drip pans under the blowers of the HVAC system that supplied air to the dialysis center. Observational study of 21 patients detected suboptimal contact time with antiseptic agents used to prepare dialysis access sites.

Conclusion.

The report of this outbreak adds to previous published reports of Phialemonium infection occurring in immunocompromised patients who likely acquired infection in the healthcare setting. Recovery of this mold from blood culture should be considered indicative of infection until proven otherwise. Furthermore, an investigation into possible healthcare-related environmental reservoirs should be considered.

Notes from the Field: Probable Mucormycosis Among Adult Solid Organ Transplant Recipients at an Acute Care Hospital - Pennsylvania, 2014-2015

On September 17, 2015, the Pennsylvania Department of Health (PADOH) notified CDC of a cluster of three potentially health care-associated mucormycete infections that occurred among solid organ transplant recipients during a 12-month period at hospital A. On September 18, hospital B reported that it had identified an additional transplant recipient with mucormycosis. Hospitals A and B are part of the same health care system and are connected by a pedestrian bridge. PADOH requested CDC's assistance with an on-site investigation, which started on September 22, to identify possible sources of infection and prevent additional infections.

Notes from the field: Fatal gastrointestinal mucormycosis in a premature infant associated with a contaminated dietary supplement--Connecticut, 2014

In October 2014, a hospital in Connecticut notified CDC and the Connecticut Department of Public Health of a fatal case of gastrointestinal mucormycosis in a preterm infant. The infant, born at 29 weeks' gestation and weighing 1,400 grams (about 3 pounds), had developed signs and symptoms initially consistent with necrotizing enterocolitis approximately 1 week after birth. Exploratory laparotomy revealed complete ischemia of the gastrointestinal tract from the esophagus to the rectum; a portion of necrotic cecum was sent for microscopic examination. Following surgery, the infant developed multiple areas of vascular occlusion, including a large clot in the aorta, findings not usually associated with necrotizing enterocolitis. The infant died soon after. Histopathology results from the resected cecum revealed an angioinvasive fungal infection consistent with mucormycosis. Gastrointestinal mucormycosis is an extremely rare fungal infection caused by mold in the order Mucorales. It occurs predominantly in low birth weight infants, patients with diarrhea and malnutrition, and those receiving peritoneal dialysis; mortality is 85%. Local investigation revealed that the infant had received a dietary supplement, ABC Dophilus Powder, for 7 days, beginning on day 1 of life.

Contaminated Product Water as the Source ofPhialemonium curvatumBloodstream Infection among Patients Undergoing Hemodialysis

Objective.

We investigated a cluster of cases of bloodstream infection (BSI) due to the moldPhialemoniumat a hemodialysis center in Illinois and conducted a cohort study to identify risk factors.

Design.

Environmental assessment and cohort study.

Setting.

A hemodialysis center in a tertiary care hospital.

Methods.

A case patient was defined as a person who underwent dialysis at the center and had a blood sample that tested positive forPhialemonium curvatumon culture. We reviewed microbiology and medical records and tested water, surface, and dialysate samples by culture. Molds isolated from environmental and clinical specimens were identified by their morphological features and confirmed by sequencing DNA.

Results.

We identified 2 case patients with BSI due toP. curvatum. Both became febrile and hypotensive while undergoing dialysis on the same machine at the same treatment station, although on different days. Dialysis machines were equipped with waste handling option ports that are used to discard dialyzer priming fluid. We isolatedP. curvatumfrom the product water (ie, water used for dialysis purposes) at 2 of 19 treatment stations, one of which was the implicated station.

Conclusion.

The source ofP. curvatumwas likely the water distribution system. To our knowledge, this is the first report of patients acquiring a mold BSI from contaminated product water. The route of exposure in these cases of BSI due toP. curvatummay be related to the malfunction and improper maintenance of the waste handling option ports. Waste handling option ports have been previously implicated as the source of bacterial BSI due to the backflow of waste fluid into a patient's blood line. No additional cases of infection were noted after remediation of the water distribution system and after discontinuing use of waste handling option ports at the facility.

Valley fever: finding new places for an old disease: Coccidioides immitis found in Washington State soil associated with recent human infection

We used real-time polymerase chain reaction and culture to demonstrate persistent colonization of soils by Coccidioides immitis, an agent of valley fever, in Washington State linked to recent human infections and located outside the endemic range. Whole-genome sequencing confirmed genetic identity between isolates from soil and one of the case-patients.

Coccidioides immitis identified in soil outside of its known range - Washington, 2013

Coccidioidomycosis ("valley fever") is caused by inhaling spores of the soil-dwelling fungi Coccidioides immitis or Coccidioides posadasii. Most infections are subclinical. When clinical manifestations do occur (typically 1-4 weeks after exposure), they are similar to those associated with influenza or community-acquired pneumonia. Disseminated disease is rare. Residual pulmonary nodules can lead to chronic lung disease. Fluconazole or other triazoles often are used for treatment, but mild cases often resolve without specific therapy. A total of 17,802 cases were reported in the United States in 2012.

Real-time PCR assays for genotyping of Cryptococcus gattii in North America

Background

Cryptococcus gattii has been the cause of an ongoing outbreak starting in 1999 on Vancouver Island, British Columbia and spreading to mainland Canada and the US Pacific Northwest. In the course of the outbreak, C. gattii has been identified outside of its previously documented climate, habitat, and host disease. Genotyping of C. gattii is essential to understand the ecological and geographical expansion of this emerging pathogen.

Methods

We developed and validated a mismatch amplification mutation assay (MAMA) real-time PCR panel for genotyping C. gattii molecular types VGI-VGIV and VGII subtypes a,b,c. Subtype assays were designed based on whole-genome sequence of 20 C. gattii strains. Publically available multilocus sequence typing (MLST) data from a study of 202 strains was used for the molecular type (VGI-VGIV) assay design. All assays were validated across DNA from 112 strains of diverse international origin and sample types, including animal, environmental and human.

Results

Validation revealed each assay on the panel is 100% sensitive, specific and concordant with MLST. The assay panel can detect down to 0.5 picograms of template DNA.

Conclusions

The (MAMA) real-time PCR panel for C. gattii accurately typed a collection of 112 diverse strains and demonstrated high sensitivity. This is a time and cost efficient method of genotyping C. gattii best suited for application in large-scale epidemiological studies.

Epidemiology, Clinical Manifestations, and Therapy of Infections Caused by Dematiaceous Fungi

The dematiaceous (brown-pigmented) fungi are a large and heterogenous group of moulds that cause a wide range of diseases including phaeohyphomycosis, chromoblastomycosis, and eumycotic mycetoma. Among the more important human pathogens are Alternaria species, Bipolaris species, Cladophialophora bantiana, Curvularia species, Exophiala species, Fonsecaea pedrosoi, Madurella species, Phialophora species, Scedosporium prolificans, Scytalidium dimidiatum, and Wangiella dermatitidis. These organisms are widespread in the environment, being found in soil, wood, and decomposing plant debris. Cutaneous, subcutaneous, and corneal infections with dematiaceous fungi occur worldwide, but are more common in tropical and subtropical climates. Infection results from traumatic implantation. Most cases occur in immunocompetent individuals. Dematiaceous moulds are also important causes of invasive sinusitis and allergic fungal sinusitis. Infection is thought to follow inhalation. Although cerebral infection is the commonest form of systemic phaeohyphomycosis, other localized deep forms of the disease, such as arthritis, and endocarditis, have been reported. Disseminated infection is uncommon, but its incidence is increasing, particularly among immunocompromised individuals. Scedosporium prolificans is the most frequent cause. A number of dematiaceous fungi are neurotropic, including Cladophialophora bantiana, Ramichloridium mackenziei, and Wangiella dermatitidis. Although cases have occurred in immunocompromised persons, cerebral phaeohyphomycosis is most common in immunocompetent individuals with no obvious risk factors. Most forms of disease caused by dematiaceous fungi require both surgical and medical treatment. Itraconazole is currently the most effective antifungal agent for chromoblastomycosis and subcutaneous phaeohyphomycosis, while ketoconazole remains useful for mycetoma. Extensive surgical debridement combined with amphotericin B treatment is recommended for chronic invasive sinusitis. Long-term treatment with itraconazole has led to improvement or remission in some patients that had failed to respond to amphotericin B. Allergic fungal sinusitis requires surgical removal of impacted mucin combined with postoperative oral corticosteroids. Antifungal treatment is not usually of benefit, but post-operative itraconazole may reduce the need for reoperation. The clinical outcome of cerebral and other deep-seated forms of phaeohyphomycosis is dismal, with long-term survival being reported only when complete surgical resection of discrete lesions is possible. The development of new antifungal agents and combination treatment may help to improve the management of these infections.

Utility of (1-3)-β-D-glucan testing for diagnostics and monitoring response to treatment during the multistate outbreak of fungal meningitis and other infections

BACKGROUND

 The 2012 outbreak of fungal meningitis associated with contaminated methylprednisolone produced by a compounding pharmacy has resulted in >750 infections. An important question facing patients and clinicians is the duration of antifungal therapy. We evaluated (1-3)-β-d-glucan (BDG) as a marker for monitoring response to treatment.

METHODS

 We determined sensitivity and specificity of BDG testing using the Fungitell assay, by testing 41 cerebrospinal fluid (CSF) specimens from confirmed cases of fungal meningitis and 66 negative control CSF specimens. We also assessed whether BDG levels correlate with clinical status by using incident samples from 108 case patients with meningitis and 20 patients with serially collected CSF.

RESULTS

 A cutoff value of 138 pg/mL provided 100% sensitivity and 98% specificity for diagnosis of fungal meningitis in this outbreak. Patients with serially collected CSF were divided into 2 groups: those in whom BDG levels declined with treatment and those in whom BDG remained elevated. Whereas most patients with a decline in CSF BDG had clinical improvement, all 3 patients with continually elevated BDG had poor clinical outcomes (stroke, meningitis relapse, or development of new disease).

CONCLUSIONS

 Our data suggest that measuring BDG in CSF is a highly sensitive test for diagnosis of fungal meningitis in this outbreak. Analysis of BDG levels in serially collected CSF demonstrated that BDG may correlate with clinical response. Routine measurement of BDG in CSF may provide useful adjunctive data for the clinical management of patients with outbreak-associated meningitis.

Fungal infections associated with contaminated methylprednisolone injections

BACKGROUND

Fungal infections are rare complications of injections for treatment of chronic pain. In September 2012, we initiated an investigation into fungal infections associated with injections of preservative-free methylprednisolone acetate that was purchased from a single compounding pharmacy.

METHODS

Three lots of methylprednisolone acetate were recalled by the pharmacy; examination of unopened vials later revealed fungus. Notification of all persons potentially exposed to implicated methylprednisolone acetate was conducted by federal, state, and local public health officials and by staff at clinical facilities that administered the drug. We collected clinical data on standardized case-report forms, and we tested for the presence of fungi in isolates and specimens by examining cultures and performing polymerase-chain-reaction assays and histopathological and immunohistochemical testing.

RESULTS

By October 19, 2012, more than 99% of 13,534 potentially exposed persons had been contacted. As of July 1, 2013, there were 749 reported cases of infection in 20 states, with 61 deaths (8%). Laboratory evidence of Exserohilum rostratum was present in specimens from 153 case patients (20%). Additional data were available for 728 case patients (97%); 229 of these patients (31%) had meningitis with no other documented infection. Case patients had received a median of 1 injection (range, 1 to 6) of implicated methylprednisolone acetate. The median age of the patients was 64 years (range, 15 to 97), and the median incubation period (the number of days from the last injection to the date of the first diagnosis) was 47 days (range, 0 to 249); 40 patients (5%) had a stroke.

CONCLUSIONS

Analysis of data from a large, multistate outbreak of fungal infections showed substantial morbidity and mortality. The infections were associated with injection of a contaminated glucocorticoid medication from a single compounding pharmacy. Rapid public health actions included prompt recall of the implicated product, notification of exposed persons, and early outreach to clinicians.

Clinical findings for fungal infections caused by methylprednisolone injections

BACKGROUND

Since September 18, 2012, public health officials have been investigating a large outbreak of fungal meningitis and other infections in patients who received epidural, paraspinal, or joint injections with contaminated lots of methylprednisolone acetate. Little is known about infections caused by Exserohilum rostratum, the predominant outbreak-associated pathogen. We describe the early clinical course of outbreak-associated infections.

METHODS

We reviewed medical records for outbreak cases reported to the Centers for Disease Control and Prevention before November 19, 2012, from the six states with the most reported cases (Florida, Indiana, Michigan, New Jersey, Tennessee, and Virginia). Polymerase-chain-reaction assays and immunohistochemical testing were performed on clinical isolates and tissue specimens for pathogen identification.

RESULTS

Of 328 patients without peripheral-joint infection who were included in this investigation, 265 (81%) had central nervous system (CNS) infection and 63 (19%) had non-CNS infections only. Laboratory evidence of E. rostratum was found in 96 of 268 patients (36%) for whom samples were available. Among patients with CNS infections, strokes were associated with an increased severity of abnormalities in cerebrospinal fluid (P<0.001). Non-CNS infections were more frequent later in the course of the outbreak (median interval from last injection to diagnosis, 39 days for epidural abscess and 21 days for stroke; P<0.001), and such infections developed in patients with and in those without meningitis.

CONCLUSIONS

The initial clinical findings from this outbreak suggest that fungal infections caused by epidural and paraspinal injection of a contaminated glucocorticoid product can result in a broad spectrum of clinical disease, reflecting possible variations in the pathogenic mechanism and in host and exposure risk factors. (Funded by the Centers for Disease Control and Prevention.).

Preliminary laboratory report of fungal infections associated with contaminated methylprednisolone injections

In September 2012, the Centers for Disease Control and Prevention (CDC) initiated an outbreak investigation of fungal infections linked to injection of contaminated methylprednisolone acetate (MPA). Between 2 October 2012 and 14 February 2013, the CDC laboratory received 799 fungal isolates or human specimens, including cerebrospinal fluid (CSF), synovial fluid, and abscess tissue, from 469 case patients in 19 states. A novel broad-range PCR assay and DNA sequencing were used to evaluate these specimens. Although Aspergillus fumigatus was recovered from the index case, Exserohilum rostratum was the primary pathogen in this outbreak and was also confirmed from unopened MPA vials. Exserohilum rostratum was detected or confirmed in 191 specimens or isolates from 150 case patients, primarily from Michigan (n=67 patients), Tennessee (n=26), Virginia (n=20), and Indiana (n=16). Positive specimens from Michigan were primarily abscess tissues, while positive specimens from Tennessee, Virginia, and Indiana were primarily CSF. E. rostratum antifungal susceptibility MIC50 and MIC90 values were determined for voriconazole (1 and 2 μg/ml, respectively), itraconazole (0.5 and 1 μg/ml), posaconazole (0.5 and 1 μg/ml), isavuconazole (4 and 4 μg/ml), and amphotericin B (0.25 and 0.5 μg/ml). Thirteen other mold species were identified among case patients, and four other fungal genera were isolated from the implicated MPA vials. The clinical significance of these other fungal species remains under investigation. The laboratory response provided significant support to case confirmation, enabled linkage between clinical isolates and injected vials of MPA, and described significant features of the fungal agents involved in this large multistate outbreak.

Exserohilum infections associated with contaminated steroid injections: a clinicopathologic review of 40 cases

September 2012 marked the beginning of the largest reported outbreak of infections associated with epidural and intra-articular injections. Contamination of methylprednisolone acetate with the black mold, Exserohilum rostratum, was the primary cause of the outbreak, with >13,000 persons exposed to the potentially contaminated drug, 741 confirmed drug-related infections, and 55 deaths. Fatal meningitis and localized epidural, paraspinal, and peripheral joint infections occurred. Tissues from 40 laboratory-confirmed cases representing these various clinical entities were evaluated by histopathological analysis, special stains, and IHC to characterize the pathological features and investigate the pathogenesis of infection, and to evaluate methods for detection of Exserohilum in formalin-fixed, paraffin-embedded (FFPE) tissues. Fatal cases had necrosuppurative to granulomatous meningitis and vasculitis, with thrombi and abundant angioinvasive fungi, with extensive involvement of the basilar arterial circulation of the brain. IHC was a highly sensitive method for detection of fungus in FFPE tissues, demonstrating both hyphal forms and granular fungal antigens, and PCR identified Exserohilum in FFPE and fresh tissues. Our findings suggest a pathogenesis for meningitis involving fungal penetration into the cerebrospinal fluid at the injection site, with transport through cerebrospinal fluid to the basal cisterns and subsequent invasion of the basilar arteries. Further studies are needed to characterize Exserohilum and investigate the potential effects of underlying host factors and steroid administration on the pathogenesis of infection.

One fungus, one name: defining the genus Fusarium in a scientifically robust way that preserves longstanding use

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.

Trichosporon asahii among intensive care unit patients at a medical center in Jamaica

We investigated an increase in Trichosporon asahii isolates among inpatients. We identified 63 cases; 4 involved disseminated disease. Trichosporon species was recovered from equipment cleaning rooms, washbasins, and fomites, which suggests transmission through washbasins. Patient washbasins should be single-patient use only; adherence to appropriate hospital disinfection guidelines was recommended.

Necrotizing cutaneous mucormycosis after a tornado in Joplin, Missouri, in 2011

BACKGROUND

Mucormycosis is a fungal infection caused by environmentally acquired molds. We investigated a cluster of cases of cutaneous mucormycosis among persons injured during the May 22, 2011, tornado in Joplin, Missouri.

METHODS

We defined a case as a soft-tissue infection in a person injured during the tornado, with evidence of a mucormycete on culture or immunohistochemical testing plus DNA sequencing. We conducted a case-control study by reviewing medical records and conducting interviews with case patients and hospitalized controls. DNA sequencing and whole-genome sequencing were performed on clinical specimens to identify species and assess strain-level differences, respectively.

RESULTS

A total of 13 case patients were identified, 5 of whom (38%) died. The patients had a median of 5 wounds (range, 1 to 7); 11 patients (85%) had at least one fracture, 9 (69%) had blunt trauma, and 5 (38%) had penetrating trauma. All case patients had been located in the zone that sustained the most severe damage during the tornado. On multivariate analysis, infection was associated with penetrating trauma (adjusted odds ratio for case patients vs. controls, 8.8; 95% confidence interval [CI], 1.1 to 69.2) and an increased number of wounds (adjusted odds ratio, 2.0 for each additional wound; 95% CI, 1.2 to 3.2). Sequencing of the D1-D2 region of the 28S ribosomal DNA yielded Apophysomyces trapeziformis in all 13 case patients. Whole-genome sequencing showed that the apophysomyces isolates were four separate strains.

CONCLUSIONS

We report a cluster of cases of cutaneous mucormycosis among Joplin tornado survivors that were associated with substantial morbidity and mortality. Increased awareness of fungi as a cause of necrotizing soft-tissue infections after a natural disaster is warranted.

Whole genome sequence typing to investigate the Apophysomyces outbreak following a tornado in Joplin, Missouri, 2011

Case reports of Apophysomyces spp. in immunocompetent hosts have been a result of traumatic deep implantation of Apophysomyces spp. spore-contaminated soil or debris. On May 22, 2011 a tornado occurred in Joplin, MO, leaving 13 tornado victims with Apophysomyces trapeziformis infections as a result of lacerations from airborne material. We used whole genome sequence typing (WGST) for high-resolution phylogenetic SNP analysis of 17 outbreak Apophysomyces isolates and five additional temporally and spatially diverse Apophysomyces control isolates (three A. trapeziformis and two A. variabilis isolates). Whole genome SNP phylogenetic analysis revealed three clusters of genotypically related or identical A. trapeziformis isolates and multiple distinct isolates among the Joplin group; this indicated multiple genotypes from a single or multiple sources. Though no linkage between genotype and location of exposure was observed, WGST analysis determined that the Joplin isolates were more closely related to each other than to the control isolates, suggesting local population structure. Additionally, species delineation based on WGST demonstrated the need to reassess currently accepted taxonomic classifications of phylogenetic species within the genus Apophysomyces.

Invasive candidiasis in Pakistan: clinical characteristics, species distribution and antifungal susceptibility

This study reports for the first time, to our knowledge, descriptive epidemiological data for 188 invasive Candida isolates from Pakistan, including species identification and antifungal susceptibility against fluconazole, itraconazole, voriconazole, caspofungin, micafungin, anidulafungin and amphotericin. Risk factors for invasive candidiasis (IC) were determined for 96 patients from Karachi, Pakistan. In adults and neonates, Candida tropicalis (38 and 36 %, respectively) was the most common species, followed in adults by Candida parapsilosis (17.8 %), Candida glabrata (15.9 %) and Candida albicans (12.3 %). C. albicans (21 %) was the second most common in neonates. In children, C. albicans (31.9 %), C. tropicalis (26.4 %) and C. parapsilosis (19.4 %) were the most common. C. albicans IC was significantly associated with paediatric age [crude odds ratio (COR) 3.46, 95 % confidence interval (CI) 1.63-7.32]. Rare species made up 17.5 % of the total isolates studied. Resistance to fluconazole was seen in C. glabrata (15 .0%) and Candida krusei (100 .0%). Only one isolate (C. glabrata) was resistant to all three echinocandins. Low MICs of fluconazole for 98 % (184/188) of isolates tested support its continued use as an empiric therapy for IC. Non-C. albicans IC was associated with the use of β-lactam inhibitor combinations (COR 3.16, 95 % CI 1.05-9.57). Use of healthcare devices was documented in 85.4 % of IC patients, whilst 75 .0% had been admitted to special care units. Surprisingly, 66.7 % of patients with IC were not obviously immunosuppressed. The high frequency of modifiable risk factors in this population indicates that candidaemia can be reduced with stringent antibiotic and infection control measures. These data will be useful for empiric selection of antifungals in Karachi, and contribute to global assessments of antifungal resistance.