Wengenack, Nancy L.

Abstract Central nervous system (CNS) phaeohyphomycosis is a rare and often fatal fungal infection. Our study reported a case series of eight CNS phaeohyphomycosis cases at our institution over the past 20 years. We did not observe the common pattern of risk factors, abscess location, or number of abscesses among them. Most patients were immunocompetent without classic risk factors for fungal infection. Early diagnosis and aggressive management with surgical intervention and prolonged antifungal therapy can lead to a favorable outcome. The study highlights the need for further research to better understand the pathogenesis and optimal management of this challenging rare infection.

Abstract Background Invasive Mold Infections (IMI) cause significant morbidity and mortality, particularly in patients with hematologic malignancies (HM) and hematopoietic stem cell transplant (HSCT) recipients. Although the risk has significantly decreased with the use of triazole agents as primary prophylaxis, breakthrough infections still occur. Risk factors for IMI have been well-described. Limited data exist on factors predicting mortality. Methods We identified cases using the Cancer registry and Microbiology data at Mayo Clinic Minnesota from 11/19/2011–8/6/2021 and Mayo Clinic Arizona and Florida from 09/13/2017–11/19/2021. We conducted a retrospective review to identify cases of proven/probable IMI per EORTC/MSG criteria. Patients who received at least 7 days of anti-mold prophylaxis were considered having breakthrough infection (Br-IMI). Survival function was estimated using the Kaplan-Meier method. We evaluated predictors of mortality using Cox regression analysis. Results 401 cases of IMI were included (80.2% aspergillosis, 10.2% fusariosis, 8.4% mucormycosis, 1.2% scedosporiosis). 189 patients had proven/probable and 212 had possible disease. 12-week mortality for the entire cohort was 33%. There were 87 cases of Br-IMI (21.6%) on mold-active prophylaxis (posaconazole n=54, voriconazole n=26, isavuconazole n=5, itraconazole n=1, liposomal amphotericin B n=1). A comparison between patients not receiving prophylaxis and those with Br-IMI is shown in Table 1. Higher proportion of patients with Br-IMI had prolonged neutropenia/lymphopenia and graft-versus-host disease involving the gastrointestinal tract or lungs. Positive Aspergillus galactomannan (index ≥ 1.0) was seen more in patients who were not on mold-active prophylaxis. Mortality was 31.5% in patients not receiving prophylaxis and 41.3% with Br-IMI (Figure 1). In multivariate analysis, age, prolonged neutropenia, active HM, Br-IMI and HSCT were associated with increased mortality (Table 2). Conclusion In this cohort, the rate of Br-IMI was significant despite the use of primary prophylaxis (mainly posaconazole). Mortality was higher in patients with Br-IMI compared to those not receiving mold-active prophylaxis. Therefore, clinicians should remain alert to the possibility of Br-IMI. Disclosures Paschalis Vergidis, MD, AbbVie: DSMB|Cidara: Grant/Research Support|Scynexis: Grant/Research Support.

Abstract Background There are not established clinical breakpoints (CBP) for antifungals against Cryptococcus species; However, the analysis of their MICs using epidemiological cut-off values (ECVs) can help to distinguish wild-type (WT) isolates from non-WT strains that may harbor intrinsic or acquired resistance to antifungals. Herein, we analyze the MIC distribution of antifungals against Cryptococcus spp. isolated over the last decade at our reference laboratory. Methods We conducted a retrospective evaluation of antifungals MICs for Cryptococcus neoformans and Cryptococcus gattii complex isolates from various sources that were processed at the Mayo Clinic Laboratory from November 18, 2011 to June 7, 2021. Antifungal susceptibility testing was performed by the Clinical & Laboratory Standards Institute (CLSI) standards (CLSI M59-ED3:2020). We used recommended ECVs to define if the isolates were WT or non-WT, and described the change in the percentage of WT isolates over time. Results During the study period, C. neoformans was isolated from 632 samples collected from 533 patients. Sample sources included cultures from blood (n=301), cerebrospinal fluid (n=230), respiratory (n=71), and other sources (n=30). The overall percentage of WT isolates for amphotericin B (AMB), 5-flucytosine, and fluconazole were 77%, 98% and 91% respectively with no significant difference based on various sources (Table). We noticed an overall increase in MICs for AMB, with 100% WT isolates in 2011 compared to 79% in 2021. No such increase was seen for fluconazole or 5-Flucytosine (Figure). Irrespective of the source or the year of isolation, WT strains for itraconazole, voriconazole, and posaconazole were consistently > 93%. C. gattii was isolated from 16 samples, and 94% were WT strains for AMB and 100% for the other antifungals. CLSI, Clinical and Laboratory Standard Institute; CSF, cerebrospinal fluid; ECVs, epidemiologic cut-off values. AMB, amphotericin B; FLU, fluconazole; 5FC, 5-flucytosine. Conclusion In the last decade, we have observed an overall increase in MICs of AMB for C. neoformans. The number of WT strains for other antifungals was high and not significantly changed during the study frame. Further studies are needed to identify the clinical implications of these findings. Disclosures Paschalis Vergidis, MD, AbbVie: DSMB|Cidara: Grant/Research Support|Scynexis: Grant/Research Support.

Abstract Background The yield of next-generation sequencing (NGS) added to a Sanger sequencing–based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR) assay was evaluated in clinical practice for diagnosis of bacterial infection. Methods PCR targeting the V1 to V3 regions of the 16S rRNA gene was performed, with amplified DNA submitted to Sanger sequencing and/or NGS (Illumina MiSeq) or reported as negative, depending on the cycle threshold value. A total of 2146 normally sterile tissues or body fluids were tested between August 2020 and March 2021. Clinical sensitivity was assessed in 579 patients from whom clinical data were available. Results Compared with Sanger sequencing alone (400 positive tests), positivity increased by 87% by adding NGS (347 added positive tests). Clinical sensitivity of the assay that incorporated NGS was 53%, which was higher than culture (42%, P < .001), with an impact on clinical decision-making in 14% of infected cases. Clinical sensitivity in the subgroup that received antibiotics at sampling was 41% for culture and 63% for the sequencing assay (P < .001). Conclusions Adding NGS to Sanger sequencing of the PCR-amplified 16S rRNA gene substantially improved test positivity. In the patient population studied, the assay was more sensitive than culture, especially in patients who had received antibiotic therapy.

Aims Fungal and mycobacterial periprosthetic joint infections (PJI) are rare events. Clinicians are wary of missing these diagnoses, often leading to the routine ordering of fungal and mycobacterial cultures on periprosthetic specimens. Our goal was to examine the utility of these cultures and explore a modern bacterial culture technique using bacterial blood culture bottles (BCBs) as an alternative. Methods We performed a retrospective review of patients diagnosed with hip or knee PJI between 1 January 2010 and 31 December 2019, at the Mayo Clinic in Rochester, Minnesota, USA. We included patients aged 18 years or older who had fungal, mycobacterial, or both cultures performed together with bacterial cultures. Cases with positive fungal or mycobacterial cultures were reviewed using the electronic medical record to classify the microbiological findings as representing true infection or not. Results There were 2,067 episodes of PJI diagnosed within the study period. A total of 3,629 fungal cultures and 2,923 mycobacterial cultures were performed, with at least one of these performed in 56% of episodes (n = 1,157). Test positivity rates of fungal and mycobacterial cultures were 5% (n = 179) and 1.2% (n = 34), respectively. After a comprehensive review, there were 40 true fungal and eight true mycobacterial PJIs. BCB were 90% sensitive in diagnosing true fungal PJI and 100% sensitive in detecting rapidly growing mycobacteria (RGM). Fungal stains were performed in 27 true fungal PJI but were only positive in four episodes (14.8% sensitivity). None of the mycobacterial stains was positive. Conclusion Routine fungal and mycobacterial stains and cultures should not be performed as they have little clinical utility in the diagnosis of PJI and are associated with significant costs. Candida species and RGM are readily recovered using BCB. More research is needed to predict rare non- Candida fungal and slowly growing mycobacterial PJI that warrant specialized cultures. Cite this article: Bone Joint J 2022;104-B(1):53–58.

Background: Blastomycosis can cause severe disease with progressive respiratory failure and dissemination even in immunocompetent individuals. We sought to evaluate risk factors for severe disease and mortality using clinical and laboratory data within a large health system in an endemic area. Methods: We performed a retrospective cohort study of patients diagnosed with blastomycosis at all Mayo Clinic sites from 1 January 2004 through 31 March 2020. Diagnosis was established by culture, histopathology/cytopathology, serology, antigen testing, or PCR. Disease was categorized as mild for patients treated in the outpatient setting, moderate for hospitalized patients who did not require intensive care, and severe for patients admitted to the intensive care unit. Logistic regression was used to evaluate risk factors for severe disease. A Cox proportional hazards model was constructed to evaluate mortality. Findings: We identified 210 patients diagnosed with blastomycosis. Mean age was 51 years (range, 6–84). Most subjects were male (71.0%). Extrapulmonary disease was confirmed in 24.8%. In this cohort, 40.5% of patients had mild disease, 37.6% had moderate disease, and 21.9% had severe disease. Independent risk factors for severe disease were neutrophilia (odds ratio (OR) 3.35 (95% CI 1.53–7.35), p = 0.002) and lymphopenia (OR 3.34 (95% CI 1.59–7.03), p = 0.001). Mortality at 90 days was 11.9%. Median time from diagnosis to death was 23 days (interquartile range 8–31 days). Independent risk factors for mortality were age (OR 1.04 (95% CI 1.01–1.08), p = 0.009), neutrophilia (OR 2.84 (95% CI 1.04–7.76), p = 0.041), and lymphopenia (OR 4.50 (95% CI 1.67–12.11), p = 0.003). Blastomyces immunodiffusion had an overall sensitivity of 39.6% (95% CI 30.1–49.8). Sensitivity was higher among those who were tested 4 weeks or longer after the onset of symptoms. Urine Blastomyces antigen had a significantly higher sensitivity of 80.8% (95% CI 68.1–89.2) compared to serology. There was a trend towards higher antigen concentration in patients with severe disease. The sensitivity of PCR from respiratory specimens was 67.6% (95% CI 50.1–85.5). Conclusion: In this cohort, we did not find an association between pharmacologic immunosuppression and disease severity. Lymphopenia at diagnosis was an independent risk factor for mortality. This simple marker may aid clinicians in determining disease prognosis.