Grocott-Gomori Methenamine Silver Stain Research Articles

First confirmed case of equine pythiosis in Northern Veracruz, Mexico

A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass had a granulomatous and crater-shaped appearance, with serosanguinous discharge and the presence of fistulas with caseous material. The tumor was removed by surgery and sent to the laboratory for diagnosis. Histopathology was performed using Grocott-Gomori methenamine silver stain. The presence of necrotic material, fibrosis, infiltrated cells, and brown-colored hyphae, characteristic of members of the genus Pythium, were observed. To identify the infecting species, conventional PCRs for the amplification of the ITS-1 was carried out. Histopathological and PCR tests confirmed infection by a Pythium insidiosum strain closely associated with previous records from the US and Central America. Our report represents the first molecularly confirmed case of equine pythiosis in Mexico.

Disseminated dermatophytosis and acquired immunodeficiency syndrome:literature review and presentation of clinical experience

Introduction: Dermatophytosis are very common fungal infections caused by the fungal species Microsporum, Epidermophyton or Trichophyton, which mostly affect the skin, the interdigital region, groin and scalp. Although they do not cause serious diseases, in patients with the human immunodeficiency virus the infection manifests itself and evolves exuberantly, usually with extensive and disseminated lesions. Objective: To review the literature on dermatophytosis in people living with human immunodeficiency virus and to present the experience in clinical care in a patient living with human immunodeficiency virus with extensive and disseminated dermatophytosis. Methods: A literature review on the topic was carried out in the PubMed/National Library of Medicine – USA databases, using the keywords dermatophytosis, or dermatophytosis associated with the words AIDS, human immunodeficiency virus or immunodeficiency, from 1988–2022. The clinical experience showed a patient living with human immunodeficiency virus developing AIDS and presenting with disseminated skin lesions. Samples of the lesion were collected by scraping, which were submitted to culture and there was growth of fungi of the Trichophyton sp genus. A biopsy of the lesion was also performed using the Grocott-Gomori's Methenamine Silver stain. Results: We found 1,014 articles, of which only 34 presented a direct correlation with our paper, and were used to discuss the main themes narrated in this article. We present clinical experience in the management of a patient with human immunodeficiency virus/AIDS and low adherence to antiretroviral treatment, showing extensive and disseminated erythematous-squamous lesions with a clinical diagnosis of tinea corporis, manifesting with a clinical picture usually not found in immunocompetent patients. The diagnosis was confirmed by laboratory tests with isolation of the Trichophyton sp fungus. The patient was treated with oral fluconazole, with complete remission of the clinical picture after two months. She was also thoroughly encouraged to use the prescribed antiretroviral medication correctly. Conclusion: Dermatophytosis in patients living with human immunodeficiency virus can present extensive and disseminated forms. The antifungal treatment is quite effective, with remission of the condition. Antiretroviral therapy is an important adjuvant for better recovery of the sickness.

Histological Stains in the Past, Present, and Future.

Certain contemporary histology stains and methods are not the same as those used in the past. This progression has delved into the requirement for more precise, less complex, and efficient staining procedures. The objective of this study is to assess historical and contemporary stains and procedures, as well as the challenges surrounding their improvement. Carmine, hematoxylin, silver nitrate, Giemsa, trichome stain, Gram stain, and mauveine were among the first histological stains discovered in nature. Aside from their utility in the study of tissues at the time, they also laid the groundwork for the development of commercial dyes that are still in use today. Hematoxylin and eosin, Ziehl-Nielsen (ZN) stain, periodic acid-Schiff stain, and Grocott-Gomori methenamine silver stain are some of the most recently developed histological stains. The future of histological stains and processes appears to be influenced by technological advancements and the demand for cost-effective diagnostic approaches in the healthcare system. Thus, currently used histological stains appear to be economical, quick, and reliable tools for interpreting, archiving, and delivering essential diagnoses that could not be achieved by any other means.

Genetic polymorphisms associated with treatment failure and mortality in pediatric Pneumocystosis

Data on the genetic diversity of Pneumocystis jirovecii causing Pneumocystis pneumonia (PCP) among children are still limited, and there are no available data from the Indian subcontinent, particularly associations between genotypes and clinical characteristics. A total of 37 children (62 days-12 years [median 5.5 years]) were included in this study. Pneumocystis was diagnosed by microscopy using Grocott-Gomori methenamine silver stain in 12 cases and by nested PCR using mtLSUrRNA in 25 cases. Genotyping was performed using three different genes, mitochondrial large subunit ribosomal RNA (mtLSUrRNA), dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR). mtLSUrRNA genotype 3 and novel mutations at the gene target DHFR (401 T > C) and DHPS 96/98 were frequently observed and clinically associated with severe PCP and treatment failure. Phylogenetic analyses revealed 13 unique sequence types (STs). Two STs (i) 3-DHFR 401 T > C-DHPS 96/98 – PJ1 and (ii) 3-DHFR 401 T > C-DHPS 96- PJ3 were significantly associated with treatment failure and high mortality among PCP-positive patients. In conclusion, the present study strongly suggests the emergence of virulent P. jirovecii strains or genetic polymorphisms, leading to treatment failure and high mortality. Our study is the first of its kind from the Indian subcontinent and has highlighted the genetic diversity of Pneumocystis jirovecii among children and their clinical outcomes. These findings emphasize the need to focus more on genotypes to better understand the epidemiology of Pneumocystis pneumonia.

46-Year-Old Man With Lower Back Pain

46-Year-Old Man With Lower Back Pain

PP - ORAL PARACOCCIDIOIDOMYCOSIS: A CASE REPORT

Paracoccidioidomycosis is a mucocutaneous disease that often involves the oral mucosa and may clinically resemble other infectious and neoplastic processes. The present report describes a Brazilian patient from the northeast region of the country who developed oral manifestations due to Paracoccidioides brasiliensis infection. A 59-year-old black male presented with a symptomatic ulcer, with a granular purpuric surface, which appeared four months before the appointment. The patient has been a heavy smoker and an alcohol addict for 44 years. No productive cough was observed, but the patient was much debilitated. Palpable and symptomatic submandibular lymph nodes were observed. The oral examination showed ulcerated lesions with granular surface, in the form of mulberry-like granulomatous lesions, located in the lower lip vermilion border, and on the gingival, tongue and buccal mucosae. Characteristic fungal cells with characteristic granulomatous inflammatory reaction were present in HE and Grocott-Gomori methenamine silver stain. The patient was referred to and treated at the infectology center. The whole diagnostic process was conducted by a stomatologist. The patient presented undiagnosed pulmonary involvement. This case shows that the stomatologist has an important role in the early diagnosis of this condition because adequate therapy can prevent extensive tissue destruction. Keywords: Mouth Diseases. Paracoccidioidomycosis.

Chronic skin ulcers in a patient returning from Mexico

A 27-year-old Chilean man presented with a 3 month history of cutaneous ulcers accompanied by intermittent fever, night sweats, dry cough, and weight loss. He had recently returned from a 10-month stay at the Yucatan Peninsula, Mexico, where his clinical problems had started with a skin lesion on his forehead, which he related to an insect bite. Samples of this lesion had been diagnosed in Mexico as cutaneous leishmaniasis. Shortly before returning to Chile, he was tested and found to be positive for HIV. On admission, he had various small maculopapular lesions on his chest and several skin ulcers on his shoulder and face (fi gure, A). CT scans showed several pulmonary nodular lesions and hepatosplenomegaly. His CD4 count was 75 cells per μL and his HIV viral load was 110 000 copies per mL; serology for toxoplasmosis, syphilis, Chagas disease, and Cryptococcus neoformans antigen were negative. Scrapings of the lateral margins of a skin ulcer were taken to confi rm the previous suspicion of cutaneous leish maniasis. Giemsa stains showed numerous intracellular and extracellular oval structures with a diameter of 2–4 μm (fi gure, B). Because kinetoplasts (densely stained rod-shaped structure representing mitochondrial DNA), which are pathognomonic for Leishmania spp parasites, were absent, histoplasmosis was suspected. This suspicion was verifi ed by Grocott-Gomori methenamine silver stain showing several numerous darkly stained yeast-like elements (fi gure, C). With antifungal treatment (amphotericin B, itraconazole) the fever subsided and the patient recovered; skin ulcers healed with scarring (fi gure, D). Oral itraconazole was continued for 12 months. Currently, the patient is still on his fi rst-line antiretroviral regimen (abacavir, lamivudine, raltegravir) and has undetectable viral loads. Although his CD4 count is maintained below 100 cells per μL, he is clinically stable and asymptomatic. Histoplasma capsulatum is an endemic fungal agent causing pulmonary infection after inhalation of spores. Immuno compromised patients might have life-threatening systemic infections, including cutaneous manifestations, which are more frequently reported from Latin America. Microscopic examination of tissue samples permits rapid diagnosis and initiation of therapy. However, in specimens of chronic skin ulcers, H capsulatum cells might easily be misdiagnosed as leishmania amastigotes because both microorganisms present as intracellular objects of the same size and shape.

A gingival manifestation of histoplasmosis leading diagnosis

Histoplasmosis is a world-wide distributed deep mycosis caused by Histoplasma capsulatum which has been endemic in many countries. We present a case involving an immunocompetent man evidencing the necessity of a multidisciplinary approach and rational requisition of exams. The disease has started as a pulmonary disease mimicking tuberculosis, although the exams have been negative. Immunodiffusion test indicate histoplasmosis, not confirmed by culture of sputum. After days the patient was forwarded by a private doctor for evaluation of oral lesions at our Department of Stomatology. An incisional biopsy revealed a nonspecific granulomatous inflammation and the Grocott-Gomori methenamine silver stain identified scarce oval structures that could represent fungal yeast. Sampling oral lesions with swab, it was observed the typical growth of H. capsulatum on culture. This case highlights the importance of doctor's integration diagnosing histoplasmosis, while a wide spectrum of clinical manifestations should be expected. Oral lesions may be the critical manifestation leading diagnosis.

Dihydropteroate synthase (DHPS) gene mutation study in HIV-Infected Indian patients with Pneumocystis jirovecii pneumonia

Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations' (55th and 57th codon) association with prior sulfa prophylaxis failure has been reported from both developed and developing countries. We conducted a prospective study to determine the prevalence of P. jirovecii DHPS mutations from 2006 to 2009 on P. jirovecii isolates obtained from HIV-infected patients with a clinical diagnosis of Pneumocystis carinii pneumonia (PCP) admitted to our tertiary care reference health center in New Delhi, India. Detection of P. jirovecii cysts was performed by direct fluorescent antibody (DFA) staining and by Grocott's-Gomori methenamine silver staining (GMS). DNA detection was performed by polymerase chain reaction (PCR) using primers for the major surface glycoprotein (MSG) gene. P. jirovecii DHPS gene was amplified by nested PCR protocol and sequenced for detecting mutations at the 55th and 57th codons. Out of 147 HIV-positive patients with suspected Pneumocystis pneumonia (PCP), 16 (10.8%) PCP positive cases were detected. Of 16 cases, nine (56.2%) were positive by DFA staining, four (25%) were positive by Grocott's-Gomori methenamine silver staining, and all 16 were positive by MSG PCR. DHPS mutations at the 55th and 57th codons were observed in 6.2% of HIV patients studied, which was relatively low compared to reports from developed nations. Prevalence of Pneumocystis jirovecii DHPS mutations associated with cotrimoxazole treatment failure may be low in the Indian subpopulation of HIV-positive patients and warrants larger studies to elucidate the true picture of Pneumocystis jirovecii sulfa drug resistance in India.

First Case Report of Histoplasmosis in a Cat in Japan

Cytological, histopathological and immunohistochemical examinations were carried out on a presumed 10-year-old Japanese cat showing vomiting and emaciation. On cytologic examination of the mass of the upper abdominal cavity, many yeast-like organisms were detected in the macrophages. At necropsy, the upper part of colon was markedly dilated with a thickened wall. The lung did not show significant changes. Histologically, severe necrotic and granulomatous lesions were observed in the colon. In the colonic lesion, the cytoplasm of the macrophages contained yeast-like organisms with irregularly shaped dots, and the cell walls of these organisms were stained black by Grocott-Gomori methenamine-silver stain. Immunohistochemically, they were found to be positive for anti-histoplasma yeast antibody. This is the first report of feline histoplasmosis in Japan.

A 36-Year-Old Woman With a Unilateral Breast Mass

A 36-Year-Old Woman With a Unilateral Breast Mass

Detection of Pneumocystis jiroveci in respiratory specimens by four staining methods.

We examined four staining methods on replicate smears of 313 respiratory specimens submitted for Pneumocystis jiroveci examination. The sensitivity and specificity of Calcofluor white stain (CW) were 73.8 and 99.6%, respectively. The sensitivity and specificity of Grocott-Gomori methenamine silver stain (GMS) were 79.4 and 99.2%, respectively. The sensitivity and specificity of Diff-Quik stain were 49.2 and 99.6%, respectively. The sensitivity and specificity of Merifluor Pneumocystis stain were 90.8 and 81.9%, respectively. Only CW and GMS had positive and negative predictive values of >90%.

Case Report. Localized pulmonary zygomycosis without pre‐existing immunocompromised status

Pulmonary zygomycosis rarely occurs without pre-existing immunocompromised disease. A 72-year-old male was found to have a nodular shadow (3 cm x 4 cm) in the right S8 and S9 on a chest X-ray. Right lower lobectomy was performed and histological examination of the resected material demonstrated pulmonary zygomycosis. Hyphae stained positively not only with Grocott-Gomori methenamine silver staining, but also with an anti-Rhizopus oryzae polyclonal antibody.

Paracoccidioidomycosis in the United States (South American Blastomycosis).

The diagnosis of paracoccidioidomycosis was made in the case of a hospitalized patient in New Orleans. The biopsy showed multiple budding and variations in fungus cell size. In the hematoxylin-eosin sections, the budding was not obvious and the first suggestion offered was that it was North American blastomycosis. The Grocott-Gomori methenamine silver stain demonstrated the multiple budding and variation in cell size to better advantage. Cultures revealed<i>Paracoccidioides brasiliensis</i>, skin tests were positive to paracoccidiodin, and results of serologic tests were positive. The patient had worked in South America for a number of years, though he was a native of the United States.