Histoplasma Capsulatum Research Articles

Interaction of Talaromyces marneffei with free living soil amoeba as a model of fungal pathogenesis.

Talaromyces (Penicillium) marneffei is an important dimorphic mycosis endemic in Southeast Asia and Southern China, but the origin and maintenance of virulence traits in this organism remains obscure. Several pathogenic fungi, including Cryptococcus neoformans, Aspergillus fumigatus, Blastomyces dermatitidis, Sporothrix schenckii, Histoplasma capsulatum and Paracoccidioides spp. interact with free living soil amoebae and data suggests that fungal pathogenic strategies may emerge from environmental interactions of these fungi with ubiquitous phagocytic microorganisms. In this study, we examined the interactions of T. marneffei with the soil amoeba Acanthamoeba castellanii. T. marneffei was rapidly ingested by A. castellanii and phagocytosis of fungal cells resulted in amoeba death after 24 h of contact. Co-culture also resulted in a rapid transition for conidia to the fission-yeast form. In addition, well-established virulence factors such as melanin and a yeast specific mannoprotein of T. marneffei were expressed during interaction with A. castellanii at 37°C. Our findings support the assumption that soil amoebae environmental predators play a role in the selection and maintenance of particular features in T. marneffei that impart virulence to this clinically important dimorphic fungus in mammalian hosts.

INVASIVE PULMONARY FUSARIOSIS WITH SUPERIMPOSED HISTOPLASMOSIS IN AN IMMUNOCOMPETENT HOST

INVASIVE PULMONARY FUSARIOSIS WITH SUPERIMPOSED HISTOPLASMOSIS IN AN IMMUNOCOMPETENT HOST

NON-HODGKIN FOLLICULAR LYMPHOMA COMPLICATED BY HISTOPLASMOSIS-INDUCED CHYLOTHORAX AND PNEUMOHYDROPERICARDITIS SECONDARY TO AN ESOPHAGOPERICARDIAL FISTULA

NON-HODGKIN FOLLICULAR LYMPHOMA COMPLICATED BY HISTOPLASMOSIS-INDUCED CHYLOTHORAX AND PNEUMOHYDROPERICARDITIS SECONDARY TO AN ESOPHAGOPERICARDIAL FISTULA

Expert Group Opinion for Diagnosis and Management of Fungal Infections in Solid Organ Transplant Recipients in South Asia

Fungal infections, are common in solid organ transplant (SOT) récipients in South Asia. Invasive fungal infections (IFI) are the third-most common cause of infections in SOT recipients in South Asia after urinary tract infection and tuberculosis and are a significant cause of morbidity and mortality in this population. There are multiple factors, which lead to poor outcomes of these patients, i.e., lack of awareness, inadequate training of physicians, poor laboratory support to diagnose these infections, and sometimes nonavailability of appropriate antifungal agents to treat these infections. Among the IFI in India, invasive candidiasis is the most common followed by mucormycosis, invasive aspergillosis, and cryptococcosis. There is an increasing prevalence of azole resistance and multi-drug resistance among candida infections in South Asia. There are drug interactions of azoles with tacrolimus, cyclosporine, and everolimus and this must be kept in mind when treating various fungal infections. Another challenge is, how to screen and treat the donors and recipients before accepting them for transplant and subsequent management of transplant recipients. The most common endemic mycoses in the Asia-Pacific region are histoplasmosis caused by Histoplasma capsulatum, talaromycosis caused by Talaromyces marneffei and sporotrichosis caused by Sporothrix schenckii. The endemic fungal infections should be kept in the differential diagnosis of pyrexia of unknown origin in transplant recipients. Finally, the outcomes of these patients can be improved by increasing awareness among transplant physicians, better and wider availability of diagnostic facilities, and appropriate use of antifungal agents to treat these infections.

S3034 Histoplasmosis Infection Presented as Cholestatic Liver Disease

Introduction: Histoplasmosis is the most common mycosis in the United States with peak incidence in the Midwest region. In ∼21% of patients with systemic histoplasmosis hyperbilirubinemia can be detected. However, cholestatic presentation of histoplasmosis infection is very rare. Here we present a case of immunocompromised patient with predominant cholestatic liver disease caused by Histoplasma Capsulatum. Case Description/Methods: This is the case of 56- years- old female who presented with– sided abdominal pain, shortness of breath, chills, hot flushes, nausea, vomiting and diarrhea. She is suffering from rheumatoid arthritis. Her medications are adalimumab, celecoxib, hydroxychloroquine. She denied alcohol intake. Her initial workup including liver function tests (LFTs) was positive for a total bilirubin 3.5 mg/dl, conjugated bilirubin 2.7 mg/dl, alkaline phosphatase – 547 U/L, AST – 152 U/L, ALT-142 U/L, and platelet count – 55 k/ul. During hospitalization her abdominal pain was getting progressively worse, and her LFTs continued to trend up. Eventually liver biopsy was performed. The results showed multiple granulomas with central necrosis, and associated portal and lobular inflammation. The fungal stain highlighted yeasts suggestive of histoplasma. Her urinary histoplasma Ag Quantitative EIA eventually came back positive -8.87 ng/ml. Viewing the normal chest x-ray and ongoing hypoxia, chest CT scan with IV contrast was performed showing 1.1 cm lung nodule in the left lower lobe. A subsequent bronchoscopy revealed budding yeasts. Patient was started on liposomal amphotericin B, and her LFTs trended down. The patient was treated with amphotericin B for 21days subsequently changed to twice-daily oral Itraconazole 200mg. At the outpatient follow up visit, patient admitted a complete resolution of her abdominal pain and improvement of her breathing status. Discussion: Liver histoplasmosis is a rare cause for cholestatic liver disease. Over the past two decades, a limited number of cases with similar clinical scenario were described. Despite of the rarity of this condition, hepatic histoplasmosis should be considered in a selected population of immunocompromised patients living in an endemic area (ex: Ohio). Inclusion of urine antigen testing for histoplasma in early workup can potentially prevent diagnostic delay.

S2014 Disseminated Histoplasmosis Presenting as Right Colon Lesions in HIV-Negative Patients: Report of Two Cases

Introduction: Histoplasma capsulatum is the most common endemic mycosis in the gastrointestinal tract of immunocompromised hosts. However, it can also present in immunocompetent patients. Terminal ileum and cecum are most commonly affected, recognized on endoscopic examination as inflammation, ulcerated lesions, or polypoid masses. In most patients, gastrointestinal manifestation takes a subclinical disease course. We present 2 cases of immunocompetent patients with colon lesions attributed to disseminated histoplasmosis. Case Description/Methods: First case is a 62-year-old African American woman admitted to the hospital due to abdominal pain, weight loss and poor oral intake. She was found to be anemic. CT revealed a large retroperitoneal mass with central necrosis suspicious for malignancy. Colonoscopy revealed a cecal ulcer (Figure A) with pathology reporting mucosal ulceration associated with granulomatous inflammation. GMS and PAS fungal stain showed small ovoid yeast forms, morphologically compatible with histoplasmosis (Figure B).Biopsy of the retroperitoneal mass was also positive for histoplasma. Second case is a 54-year-old Hispanic man admitted to the hospital with fluid overload secondary to acute renal failure attributed to post-infectious glomerulonephritis. He was also found to have anemia. Colonoscopy showed a 6 mm polyp in the ascending colon removed by cold snare technique (Figure C). Pathology reported polyp fragment with macrophages and numerous 2-4 micron non-budding yeast forms best seen on GMS stain, most consistent with histoplasmosis. CT scan showed prominent retroperitoneal lymphadenopathy. Both our patients were started in itraconazole and are being closely followed by the ID service. Discussion: Disseminated histoplasmosis is usually seen in immunocompromised patients such as those with HIV and medication-induced immunosuppression. GI involvement and symptoms can be diverse. Our first patient presented with a large retroperitoneal mass and cecal ulcer causing her abdominal discomfort. Second patient was much more subtle as histoplasmosis presented as a polypoid lesion. Both patients presented with significant anemia, which prompted endoscopic evaluation. Although the diagnosis of histoplasmosis in immunocompetent patients usually requires a high index of suspicion, gastroenterologists should be familiar with its variable presentations in the GI tract.Figure 1.: a) Histoplasma presenting as cecal ulcer. b) GMS stain showing Histoplasma. c) Polypoid lesion positive for Histoplasma.

S2011 Disseminated Histoplasmosis Involving the Whole Colon: It's Ulcers All the Way Down

Introduction: Histoplasma capsulatum is a dimorphic fungus endemic to river valleys of Eastern and Central U.S. that is spread via inhalation of spores from soil contaminated by bird or bat droppings. Disseminated Histoplasmosis (DH) spreads through the reticuloendothelial system via parasitized macrophages and can cause severe infection in immunocompromised patients with AIDS, hematologic malignancies, transplant recipients, and those receiving tumor necrosis factor (TNF)-alpha inhibitors or chronic corticosteroids. Gastrointestinal involvement in DH is frequently seen, but it is not uncommon for patients to be asymptomatic. We present a case of DH with pan-colonic ulcerations in a renal transplant patient. Case Description/Methods: A 83-year-old male with deceased donor renal transplantation on immunosuppression therapies presented with profound weakness. He was restarted on hemodialysis one month prior for declining renal allograft function which had been stable for the past 2 decades. Initial workup showed pneumonia on imaging, elevated procalcitonin, alkaline phosphatase, and pancytopenia. He developed hematochezia with worsening anemia which prompted colonoscopy that revealed deep and innumerable ulcers measuring greater than one cm in the whole colon. One large ulcer with a visible vessel near the hepatic flexure was treated with epinephrine, electrocautery, and endoclip for hemostasis. Ulcer biopsy revealed granulomatous inflammation with fungal yeast forms morphologically compatible with Histoplasma by Grocott's Methenamine Silver (GMS) staining. Bone marrow pathology was suggestive of fungal infiltration, but marrow and blood cultures were negative. Family revealed he lives in an old mold infested home and has history of visiting caves. Treatment was initiated with liposomal Amphotericin B then transitioned to oral Itraconazole. He has continued to make a strong recovery and remains on dialysis (Figure). Discussion: For healthy individuals, exposures to Histoplasma generally occur as asymptomatic to self-limited pulmonary infection. Disseminated Histoplasmosis is often undiagnosed and carries high mortality if untreated. These patients usually had past exposures with dormant inoculation that is reactivated after immunosuppression. GI involvement is common but can be non-symptomatic or with only vague abdominal complaints from colonic fungal invasion. Suspicion of DH should be met with a low threshold for endoscopic evaluation and requires tissue biopsy for diagnosis.Figure 1.: (A) Large ulcer in the cecum which was biopsied. (B) Numerous ulcers seen diffusely throughout the colon. (C, D) H&E and Grocott’s Methenamine Silver (GMS) stain of colonic mucosa with patchy ulceration and granulomatous inflammation including fungal yeast forms, morphologically compatible with Histoplasma.

CALCIFIED CAVITARY CONUNDRUM: DELAYED DIAGNOSIS OF HISTOPLASMOSIS

CALCIFIED CAVITARY CONUNDRUM: DELAYED DIAGNOSIS OF HISTOPLASMOSIS

S3003 Granulomatous Hepatitis as Primary Manifestation of Disseminated Histoplasmosis in an Immunocompetent Host Diagnosed on EUS FNA and Liver Biopsy

Introduction: Disseminated histoplasmosis (DH) presents as primarily lung manifestations with extrapulmonary involvement in immunocompromised hosts. Granulomatous hepatitis as first presentation of DH in an immunocompetent host is uncommon. Case Description/Methods: 25-year-old female presented with one month of fever, fatigue, myalgias, 30-pound weight loss, cough, nausea, vomiting, and epigastric pain. She has lived in the Midwest and southwestern US. Presenting labs: TB 1.9 mg/dL, AP 161 U/L, AST 172 U/L, ALT 463 U/L. Workup was negative for COVID, viral/autoimmune hepatitis, sarcoidosis, tuberculosis, and HIV. CT scan showed suspected gallstones and 9 mm left lower lobe noncalcified nodule. EUS showed a normal common bile duct, gallbladder sludge and enlarged porta hepatis lymph nodes which underwent fine needle aspiration (FNA). She was diagnosed with biliary colic and underwent cholecystectomy, with white plaques noted on the liver surface (A). Liver biopsy/FNA showed necrotizing granulomas (B) and fungal yeast on GMS stain (C). Although histoplasmosis urine and blood antigens were negative, histoplasmosis complement fixation was >1:256. She could not tolerate itraconazole for DH, requiring amphotericin B. She then transitioned to voriconazole, discontinued after 5 weeks due to increasing AP. However, her symptoms resolved with normal transaminases. At one year follow up, she is asymptomatic with normal liver function tests. Discussion: DH is a systemic granulomatous disease caused by Histoplasma capsulatum endemic to Ohio, Mississippi River Valley, and southeastern US. DH more commonly affects immunocompromised hosts with AIDS, immunosuppressants, and organ transplant. Gastrointestinal involvement is common in DH (70-90%) with liver involvement in 90%. However, granulomatous hepatitis as primary manifestation of DH is rare (4% of liver biopsies). Hepatic granulomas are seen in < 20%. Patients may present with nonspecific systemic symptoms. Serum/urine antigens may be negative. Gold standard for diagnosis is identifying yeast on tissue stains. Recommended treatment is amphotericin B followed by 1 year of itraconazole. However, shorter treatment duration may be effective in immunocompetent hosts. This case is unique in that granulomatous hepatitis was the first presentation of DH in our immunocompetent patient diagnosed on EUS FNA and liver biopsy. Clinicians must have a high degree of suspicion for DH in patients with fever of unknown origin especially in endemic areas regardless of immunologic status.Figure 1.: Liver surface, liver biopsy, porta hepatis lymph node FNA.

Molecular Detection of Histoplasma capsulatum in Antarctica.

We detected Histoplasma capsulatum in soil and penguin excreta in the Antarctic Peninsula by sequencing after performing species-specific PCR, confirming previous observations that this pathogen occurs more broadly than suspected. This finding highlights the need for surveillance of emerging agents of systemic mycoses and their transmission among regions, animals, and humans in Antarctica.

A CASE OF MIXED SEPTIC AND HEMORRHAGIC SHOCK DUE TO DISSEMINATED HISTOPLASMOSIS AND CRYPTOCOCCOSIS IN A PATIENT WITH HIV/AIDS

A CASE OF MIXED SEPTIC AND HEMORRHAGIC SHOCK DUE TO DISSEMINATED HISTOPLASMOSIS AND CRYPTOCOCCOSIS IN A PATIENT WITH HIV/AIDS

S3237 Pneumocystis jirovecii Infection in Cirrhosis: A Case Report and Review of the Literature

Introduction: Pneumocystis jirovecii is a fungus that causes serious pneumonia in immunocompromised individuals most classically associated with AIDS or prolonged steroid use. Immune dysfunction is a well- nown complication of cirrhosis; however, Pneumocystis pneumonia (PCP) is not typically associated with cirrhosis as a common risk factor. We present a case of PCP in a patient with cirrhosis and review the existing cases in the literature. Case Description/Methods: A 59-year-old male with past medical history of alcoholic cirrhosis (MELD 30, Child Pugh Class C) presented with sepsis secondary to spontaneous bacterial peritonitis. He reported he was 6 months sober. He initially improved on ceftriaxone alone; he did not receive steroids. On hospital day five he developed dyspnea and hypoxia. CT-angiogram revealed extensive ground glass opacities. Despite broad spectrum antimicrobials, his condition deteriorated resulting in invasive ventilation. Bronchoalveolar lavage was significant for Pneumocystis jiroveci by polymerase chain reaction. HIV testing was negative. Due to renal impairment, therapy was initiated with clindamycin and primaquine before he expired (Figure). Discussion: This case was unique in that cirrhosis was the only identified risk factor for immunosuppression which predisposed to PCP. PCP is rare outside of risk factors including AIDS, prolonged systemic steroids and other immunosuppressive therapies, organ transplantation, hematologic malignancy, and solid tumors. There were 14 similar cases in the literature. Of the 15 total cases, 66% were male; the median age was 54. Eleven were in the setting of alcoholic hepatitis, and 9 of these received steroids. However, none of the steroid exposures were significant enough to be a classic risk factor for PCP. Common comorbidities included COPD and lymphopenia. CMV pneumonia was seen in 33% of cases. Esophageal candidiasis and Histoplasma capsulatum pneumonia were also recorded. Fatality in 87% of cases suggests that PCP in cirrhosis is associated with a poor prognosis. There are multiple possible mechanisms why these patients developed PCP. Systemic inflammation related to cirrhosis may dysregulate key inflammatory mediators required for immune response to Pneumocystis. Also, Low CD4 counts related to portal hypertension and splenic sequestration may play a role, although an effective immune response also requires interplay of B cells and natural killer cells. This case and review are important reminders of the severity of immunocompromise in cirrhosis.Figure 1.: CT-Angiogram with diffuse ground glass opacities. Table 1. - Author Date Age/sex Prior steroid exposure (duration if applicable) Etiology of cirrhosis Additional conditions Treatment for PCP Death (y/n) Ikawa 2001 40M Y (10 days and 22 days with a 7 day interim in between) alcohol abuse cytomegalovirus pneumonia, esophageal candidiasis, lymphopenia none Y Faria 2007 44F present in 6 of 7 cases (median duration: 16 days)* alcohol abuse cytomegalovirus isolated in 3 of 7 cases* trimethoprim/ sulfamethoxazole (TMP/SMX) Y 49M alcohol abuse TMP/SMX Y 50M alcohol abuse TMP/SMX Y 53M alcohol abuse TMP/SMX Y 56F alcohol abuse TMP/SMX Y 58F alcohol abuse TMP/SMX Y 61M alcohol abuse TMP/SMX Y Dodi 2010 54F Y (9 days) alcohol abuse cytomegalovirus pneumonia, hepatorenal syndrome TMP/SMX Y Yee 2017 52M N hepatitis c hepatitis c, lymphopenia primaquine, clindamycin, corticosteroids, TMP/SMX N Hadfield 2019 63M N alcohol abuse COPD TMP/SMX Y Akhter 2020 67F N hepatitis c COPD steroids, antibiotics (unspecified) N Dugan 2020 64M N NASH COPD, lymphopenia, histoplasma capsulatum pneumonia TMP/SMX Y Chung 2020 43M Y (26 days) alcohol abuse n/a TMP/SMX Y Meyers 2022 59M N alcohol abuse COPD, lymphopenia clindamycin, primaquine Y *Not specified which cases had the exposures and/or conditions.

S2172 A Unique Case of Disseminated Histoplasmosis Presenting as Colonic Ulcers

Introduction: Histoplasmosis is the most common endemic mycosis in the United States with a disseminated form usually only seen in immunocompromised patients. While localized infections are usually self-limiting and often asymptomatic, some patients present with extra-pulmonary disseminated disease. Although case reports have described colonic and ileal involvement, gastrointestinal manifestations are uncommon. Here we report isolated colonic involvement of disseminated histoplasmosis in an asymptomatic patient. Case Description/Methods: A 62-year-old male with a history of end stage renal disease secondary to IgA nephropathy status post living donor renal transplant on chronic immunosuppressive therapy presented for a routine screening colonoscopy. The patient denied gastrointestinal and pulmonary symptoms to include: cough, shortness of breath, fever, abdominal pain, diarrhea and gastrointestinal bleeding. He grew up in the state of Mississippi and currently resides in Texas working in landscaping. Within the cecum, there were 2 discrete areas of abnormal appearing tissue (Figure A). A 10mm irregular, superficial ulcer with no high-risk stigmata for bleeding was also noted within the distal transverse colon (Figure B). Cold forceps biopsies were obtained at both sites. Surgical pathology with Grocott’s methenamine silver stain demonstrated abundant intra-histiocytic and extracellular organisms morphologically compatible with histoplasmosis. Given a potential for fungal morphological mimicry, the patient was serologically tested for histoplasmosis, coccidioides, and blastomyces. Ultimately, PCR from the tissue sample taken during the biopsy tested positive for Histoplasma capsulatum. The patient was started on itraconazole for 12 months duration which he tolerated without side effects and remained asymptomatic on follow up. Discussion: This case demonstrates an unusual presentation of disseminated histoplasmosis with asymptomatic colonic involvement including the variable endoscopic appearance of this fungal infection. With a mortality rate as high as 31% in the immunocompromised population gastroenterologists need to remain cognizant when encountering colonic ulcerations or abnormal mucosa in high risk patients. In addition, this case highlights the importance of tissue sampling to secure the diagnosis along with the efficacy of itraconazole in treating this potentially deadly infection.Figure 1.: A. Discrete area of anomalous tissue in the cecum B. Area of ulceration along the distal transverse colon.

Genome-scale CRISPR screening reveals that C3aR signaling is critical for rapid capture of fungi by macrophages.

The fungal pathogen Histoplasma capsulatum (Hc) invades, replicates within, and destroys macrophages. To interrogate the molecular mechanisms underlying this interaction, we conducted a host-directed CRISPR-Cas9 screen and identified 361 genes that modify macrophage susceptibility to Hc infection, greatly expanding our understanding of host gene networks targeted by Hc. We identified pathways that have not been previously implicated in Hc interaction with macrophages, including the ragulator complex (involved in nutrient stress sensing), glycosylation enzymes, protein degradation machinery, mitochondrial respiration genes, solute transporters, and the ER membrane complex (EMC). The highest scoring protective hits included the complement C3a receptor (C3aR), a G-protein coupled receptor (GPCR) that recognizes the complement fragment C3a. Although it is known that complement components react with the fungal surface, leading to opsonization and release of small peptide fragments such as C3a, a role for C3aR in macrophage interactions with fungi has not been elucidated. We demonstrated that whereas C3aR is dispensable for macrophage phagocytosis of bacteria and latex beads, it is critical for optimal macrophage capture of pathogenic fungi, including Hc, the ubiquitous fungal pathogen Candida albicans, and the causative agent of Valley Fever Coccidioides posadasii. We showed that C3aR localizes to the early phagosome during Hc infection where it coordinates the formation of actin-rich membrane protrusions that promote Hc capture. We also showed that the EMC promotes surface expression of C3aR, likely explaining its identification in our screen. Taken together, our results provide new insight into host processes that affect Hc-macrophage interactions and uncover a novel and specific role for C3aR in macrophage recognition of fungi.

Analysis of Cyp51 protein sequences shows 4 major Cyp51 gene family groups across fungi.

Azole drugs target fungal sterol biosynthesis and are used to treat millions of human fungal infections each year. Resistance to azole drugs has emerged in multiple fungal pathogens including Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum, and Aspergillus fumigatus. The most well-studied resistance mechanism in A. fumigatus arises from missense mutations in the coding sequence combined with a tandem repeat in the promoter of cyp51A, which encodes a cytochrome P450 enzyme in the fungal sterol biosynthesis pathway. Filamentous members of Ascomycota such as A. fumigatus have either 1 or 2 of 3 Cyp51 paralogs (Cyp51A, Cyp51B, and Cyp51C). Most previous research in A. fumigatus has focused on Cyp51A due to its role in azole resistance. We used the A. fumigatus Cyp51A protein sequence as the query in database searches to identify Cyp51 proteins across fungi. We found 435 Cyp51 proteins in 295 species spanning from early-diverging fungi (Blastocladiomycota, Chytridiomycota, Zoopagomycota, and Mucormycota) to late-diverging fungi (Ascomycota and Basidiomycota). We found these sequences formed 4 major Cyp51 groups: Cyp51, Cyp51A, Cyp51B, and Cyp51C. Surprisingly, we found all filamentous Ascomycota had a Cyp51B paralog, while only 50% had a Cyp51A paralog. We created maximum likelihood trees to investigate the evolution of Cyp51 in fungi. Our results suggest Cyp51 is present in all fungi with 3 paralogs emerging in Pezizomycotina, including Cyp51C which appears to have diverged from the progenitor of the Cyp51A and Cyp51B groups.

P286 Histoplasmosis in Sri Lanka

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackgroundHistoplasmosis is a systemic mycosis caused by Histoplasma capsulatum, a dimorphic fungus. More severe disease has been observed in immunocompromised individuals. Most cases occur in certain endemic regions of the world however it seems to have a much wider global distribution. Histoplasmosis is infrequently recognized in Sri Lanka and the dispersion of information on cases is fragmented.MethodThe comprehensive search of medical literature in the English language through databases from any time to February 2022. Either, culture-proven or histopathologically proven cases were selected as diagnostically confirmed histoplasmosis. Duplicate reports were excluded. All available data on demography, clinical presentation, diagnostic method, management, and clinical outcome were appraised for the reported cases.ResultOne survey of histoplasmin skin sensitivity testing and ten cases of histoplasmosis across Sri Lanka were observed during the above period. A total of 5.7% of histoplasmin positivity had been observed in the survey of histoplasmin sensitivity among 1366 Sri Lankan volunteers of the Western and the Central Provinces in 1969. Most of the patients were reported from the Central province which had the positive histoplasmin test previously. In addition, cases were observed in Southern Province, the Sabragamuwa Province, and the Eastern Province. The majority of affected individuals were adult males (90%) and pediatric patients were not observed. The clinical presentation stretched from oral lesions (the most common presentation), skin lesions, and fever of unknown origin, to adrenal crisis. Disseminated histoplasmosis was diagnosed in 50% of the patients however asymptomatic, acute pulmonary, and chronic pulmonary histoplasmosis was not observed. Both diabetes and betel chewing are likely to be linked with oral histoplasmosis and none of the patients were positive for HIV. Both histopathology and fungal culture methods were used for the diagnosis while the use of antigen and antibody testing were not popular. Both itraconazole and amphotericin B were used for the treatment of the patients with variable outcomes.ConclusionHistoplasmosis exists in Sri Lanka. The number of cases could be expected to be much higher than reported along with the increase in at-risk populations. These mandates enhance laboratory diagnostic facilities and increase the awareness of medical professionals in Sri Lanka.

P355 Pitfalls in medical mycology in India

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Background informationThere is increasing awareness of fungal infections in India. Many diagnostic medical mycology laboratories are now operating in different parts of the country. It is considered worthwhile to mention several pitfalls committed in the diagnosis of mycotic infections in India.MethodsLiterature on fungal infections in India was accessed through different search engines. Publications suggestive of inaccurate reporting were thoroughly read to pinpoint the pitfalls in diagnosis. For checking the accuracy of mycological illustrations, some of the publications were requested from the corresponding authors.ResultsSeveral accessed publications of Indian authors reported the unbelievably frequent occurrence of anthropophilic and zoophilic dermatophytes in soil. A few articles incorporating incorrect diagnoses of systemic infections have also been published in highly reputed journals. For instance, the article ‘Pathogenic Fungi in Soils of Jabalpur, India’ in Mycoses 1990; 33 (3): 116-125 reports 38% incidence of Microsporum (anthropophilic and zoophilic species) in 35 soils examined. Another publication in the August 2009 issue of the same journal mentions frequent isolation of Trichophyton verrucosum, Microsporum audouinii, and M. canis from Jaipur soils. Authors from several Botany departments in Indian Universities have erroneously reported a high frequency of these dermatophytes and T. rubrum from soils and also on Histoplasma capsulatum from some soils. No illustrations were provided for these fungi including H. capsulatum, nor was in vitro conversion of H. capsulatum to yeast form mentioned. There are also reports of erroneous diagnoses of systemic mycoses. In a paper in IJD 2015; 54:451-455, the authors from Kottayam, Kerala reported on African histoplasmosis as the first indigenous case from India. The diagnosis is doubtful as histopathology was not suggestive and the image of the blood agar culture of the fungus at 37°C showed septate cells resembling arthroconidia rather than yeast cells of Histoplasma. Another publication from a premier medical institute in North India [Intestinal Res 2019;17(1):149-152] reported a series of six cases of intestinal histoplasmosis the histopathological illustration was not at all suggestive of Histoplasma and there was no mention of attempting mycological culture.ConclusionLack of knowledge and training of workers from departments of botany and biological sciences in Indian universities has led to the misidentification of human pathogenic fungi The inaccurate diagnosis of mycotic infections has resulted generally from misidentification of the causative fungi and lack of collaboration between histopathologists and medical mycologists. The need for continued training of medical mycologists and for collaboration between the pathologists and medical mycologists is emphasized to avoid erroneous diagnoses.

P251 Disseminated Histoplasmosis in a Ghanaian HIV Patient: Role of Urine Histoplasma Antigen Testing in Rapid Diagnosis

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackgroundThe inhalation of the thermally dimorphic fungus Histoplasma capsulatum, may result in a wide spectrum of clinical manifestations, ranging from asymptomatic to acute or chronic pulmonary infection to disseminated infection. Symptomatic infections usually occur with high-level exposures or in immunocompromised patients mainly people with HIV. Despite the improved access to antiretroviral therapy, HIV-associated histoplasmosis remains a significant opportunistic infection in endemic regions including Africa. Unfortunately, histoplasmosis is rarely on the diagnostic radar of clinicians in several African countries such as Ghana due to insufficient awareness, inadequate epidemiological data, and poor fungal diagnostic capacity. Herein, we present a case of disseminated histoplasmosis in an HIV/AIDS patient in a tertiary hospital in Ghana.Case PresentationClinical history: A 43-year-old female was referred to the Dermatology Clinic of the Komfo Anokye Teaching Hospital (KATH) with symptoms of fever, cough, and anorexia. She had a history of a skin rash six weeks prior, which initially began on her face and later spread to the trunk and extremities. She was a known HIV/AIDS patient on anti-retroviral drugs (EFV, TFV, 3TC) with no other chronic conditions. She was anemic with a previous hemoglobin level of 7.6 g/dl. Initial diagnostic workup for cutaneous bacterial or viral infection detected no abnormality.ExaminationShe was semi-conscious, and her nostrils were clogged with crust. The patient appeared pale, warm, and anicteric. The face, trunk, and extremities (including palms) were covered with mucocutaneous erosions, ulcers, multiple papule plaques, and nodules. Examination of the cervix revealed the presence of lymph nodes.InvestigationsA fungal diagnostic work-up was done to rule out cutaneous or disseminated mycosis particularly cryptococcosis which was previously captured as a differential diagnosis. Serum cryptococcal antigen lateral flow assay (LFA) (CrAg LFA, IMMY) and Aspergillus galactomannan (GM) (sona Aspergillus GM LFA, IMMY) tests were both negative, but urine Histoplasma GM enzyme immunoassay (EIA) (clarus Histoplasma GM EIA, IMMY) test was positive with a very high optical density indicating high fungal burden was reported. A skin biopsy was also sent for histopathology and fungal culture. Histopathology analysis revealed the presence of yeast cells with round central nuclei and cytoplasmic clearing. Special staining with Periodic acid–Schiff (PAS) confirmed the presence of yeast cells, suggestive of histoplasmosis. Fungal culture was however negative after 8 weeks of incubation. A diagnosis of disseminated histoplasmosis was made.Treatment and outcomeThe patient was administered 200 mg bid of itraconazole. Few weeks after treatment, most of her skin lesions and ulcers were healed. The patient was discharged on itraconazole after the disappearance of some of her lesions. Few weeks later, the patient was admitted but died due to complications of anemia.ConclusionDisseminated histoplasmosis in HIV may be a relatively common but largely unrecognized condition in Ghana. This case report highlights the need to improve awareness of histoplasmosis among clinicians in Ghana and enhance laboratory capacity to provide timely simple contemporary fungal tests for rapid diagnosis and prompt initiation of effective antifungal agents.

P125 Histoplasma capsulatum modulates the immune response exerted by mesenchymal stromal cells

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM BackgroundMesenchymal stromal cells (MSCs) have become a tool not only for tissue regeneration but also for the treatment of inflammatory diseases. Several studies have demonstrated the therapeutic potential of MSCs for the treatment of noninfectious inflammatory diseases; however, they appear to play a dual role in infectious diseases. Histoplasmosis is a systemic mycosis caused by Histoplasma spp., which occurs mainly in immunosuppressed individuals; this mycosis can present a severe clinical picture with dissemination to various organs and is associated with an exacerbated inflammatory response and with anemia and pancytopenia if bone marrow is affected. So far, the effect of a possible interaction of Histoplasma with stem cells present in the bone marrow is unknown.ObjectivesTo examine, in vitro, the immunomodulatory effects of MSCs in response to H. capsulatum infection.MethodsMSCs were obtained from bone marrow of C57BL/6 male mice; after isolation and purification, they were induced to mesodermal lineages and characterized by flow cytometry. Later, the basal expression of toll-like receptor (TLR)-2, TLR4, and Dectin-1 was determined using flow cytometry. MSCs were infected with H. capsulatum yeasts (isolate CIB 1980) in a multiplicity of infection (MOI) of 5 and incubated for 24 h. In addition, some of the co-cultures were previously treated with specific blocking antibodies for TLR2 and TLR4 or with a blocking peptide specific for Dectin-1 (CLEC7A). Furthermore, phagocytosis, microbicidal, and cell proliferation assays were done, and the expression of the genes encoding the cytokines IL-1β, IL-6, IL-10, IL-17, TNF-α, and TGF-β as well as of those for arginase-1 and iNOS were assessed.ResultsWe observed that H. capsulatum has the capability to adhere and internalize within these MSCs; nonetheless, this process did not affect the survival of the fungus. The interaction of H. capsulatum with MSCs induced a slight but significantly increased expression of TLR2 but not TLR4 nor Dectin-1. In addition, this fungal interaction significantly induced an augmented expression of IL-6 and a decrease in the expression of IL-1β, IL-17, TNF-α, TGF-β, as well as the immune mediators Arg-1 and iNOS. Interestingly, blockade of these receptors did not affect phagocytosis, but increased IL-1β, IL-17, and TNF-α expression and reduced the expression of IL-6. Noteworthy, H. capsulatum induced apoptosis and inhibited the proliferation of these stem cells; furthermore, this fungus significantly reduced the expression of genes related to adipogenic differentiation and increased the expression of genes related to the osteogenic differentiation process.ConclusionsThe above results indicate that MSCs do not exert a notable antifungal effect against H. capsulatum; on the contrary, this fungal pathogen not only modulates the expression of inflammatory mediators in MSCs, by a mechanism dependent on TLR2, TLR4, and Dectin-1, but also affects their viability and their ability to differentiate into a different type of specialized cells. These events could, in principle, affect both hematopoiesis and the immune response in the infected host, and in addition, these stem cells may provide a niche for this fungus, allowing it to persist and evade host immunity.

P186 Disseminated Histoplasmosis in an immunocompetent patient in a tertiary care center in North India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM ObjectivesHistoplasmosis is a geographically restricted dimorphic fungi that causes disseminated infection in immune-competent as well as immunocompromised patients. Adrenal involvement is seen in disseminated disease but sometimes it may be the only site where then infection can be demonstrated. Early diagnosis and treatment are needed to save the patient from fatal adrenal insufficiency. We present a case of bilateral adrenal histoplasmosis in immunocompetent patient.MethodsA 63-year-old male presented to our hospital with a history of insidious onset of decreased appetite and unintentional weight loss for the last 6 months associated with generalized weakness. Patient had a history of mild to moderate intensity epigastric pain and discomfort which was intermittent in nature. Patient originally belongs to Azamgarh, Uttar Pradesh, but he was residing in Kolkata for the last 8 months.Patient had no history of fever, cough, hemoptysis, jaundice, chronic diarrhea, and steatorrhea. No history of orthostatic hypotension, salt craving, hyperpigmentation, headache, visual field disturbances, polyuria, behavioral changes, episodic headache, palpitation, diaphoresis, systemic hypertension with episodic all four-limb weakness. There was no history of abdominal striae, easy bruisability, difficulty in standing from squatting position. There was no history of tuberculosis among family members. On detailed history, it was revealed that he fed pigeons every day in the slum house where he lived in Kolkata.On the CECT abdomen it was found that there is an ill-defined hypodense enhancing lesion (72 × 52 × 77 mm) in right suprarenal region and bulky, necrosed 25 × 26 × 19 mm lesion in left suprarenal gland associated with multiple nonnecrotic paraaortic and aortic caval lymphadenopathy. He also received empirical anti-tubercular therapy for 15 days in the form of ethambutol and levofloxacin.ResultsIn all, 10% KOH wet mount of crushed smear of adrenal biopsy samples showed tissue debris and small narrow neck budding yeasts. Giemsa stain shows few small budding yeasts. Culture was put in SDA at 25°C and 37°C and incubated. On day 12, growth of colony in 25°C appears as white cottony growth with yellowish white reverse. On day 24, colony appears as buff brown with yellowish brown reverse. LPCB was done from the colony showing presence of characteristic tuberculate macroconidia (8–14) μm in diameter formed on short, hyaline, undifferentiated conidiophores and production of plenty round to pyriform microconidia (2–4 μm) in diameter, occurring on short branches and directly on the sides of the hyphae. Based on the direct microscopy and culture characteristics a diagnosis of Histoplasma capsulatum was given.ConclusionSystemic histoplasmosis is typically acquired through inhalation of microconidia or small hyphal elements in soil contaminated with bird and bat droppings leading to primary infection. This patient only manifested bilateral adrenal involvement with nonspecific symptoms.