Microbiome Alterations Driven by Trypanosoma cruzi Infection in Two Disjunctive Murine Models.

Alterations caused by Trypanosoma cruzi in the composition of gut microbiome may play a vital role in the host-parasite interactions that shapes physiology and immune responses against infection. Thus, a better understanding of this parasite-host-microbiome interaction may yield relevant information in the comprehension of the pathophysiology of the disease and the development of new prophylactic and therapeutic alternatives. Therefore, we implemented a murine model with two mice strains (BALB/c and C57BL/6) to evaluate the impact of Trypanosoma cruzi (Tulahuen strain) infection on the gut microbiome utilizing cytokine profiling and shotgun metagenomics. Higher parasite burdens were observed in cardiac and intestinal tissues, including changes in anti-inflammatory (interleukin-4 [IL-4] and IL-10) and proinflammatory (gamma interferon, tumor necrosis factor alpha, and IL-6) cytokines. Bacterial species such as Bacteroides thetaiotaomicron, Faecalibaculum rodentium, and Lactobacillus johnsonii showed a decrease in relative abundance, while Akkermansia muciniphila and Staphylococcus xylosus increased. Likewise, as infection progressed, there was a decrease in gene abundances related to metabolic processes such as lipid synthesis (including short-chain fatty acids) and amino acid synthesis (including branched-chain amino acids). High-quality metagenomic assembled genomes of L. johnsonii and A. muciniphila among other species were reconstructed, confirming, functional changes associated with metabolic pathways that are directly affected by the loss of abundance of specific bacterial taxa. IMPORTANCE Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi, presenting acute and chronic phases where cardiomyopathy, megaesophagus, and/or megacolon stand out. During the course of its life cycle, the parasite has an important gastrointestinal tract transit that leads to severe forms of CD. The intestinal microbiome plays an essential role in the immunological, physiological, and metabolic homeostasis of the host. Therefore, parasite-host-intestinal microbiome interactions may provide information on certain biological and pathophysiological aspects related to CD. The present study proposes a comprehensive evaluation of the potential effects of this interaction based on metagenomic and immunological data from two mice models with different genetic, immunological, and microbiome backgrounds. Our findings suggest that there are alterations in the immune and microbiome profiles that affect several metabolic pathways that can potentially promote the infection's establishment, progression, and persistence. In addition, this information may prove essential in the research of new prophylactic and therapeutic alternatives for CD.

Development and characterization of a new monoclonal antibody against SARS-CoV-2 NSP12 (RdRp).

SARS-CoV-2 NSP12, the viral RNA-dependent RNA polymerase (RdRp), is required for viral replication and is a therapeutic target to treat COVID-19. To facilitate research on SARS-CoV-2 NSP12 protein, we developed a rat monoclonal antibody (CM12.1) against the NSP12 N-terminus that can facilitate functional studies. Immunoblotting and immunofluorescence assay (IFA) confirmed the specific detection of NSP12 protein by this antibody for cells overexpressing the protein. Although NSP12 is generated from the ORF1ab polyprotein, IFA of human autopsy COVID-19 lung samples revealed NSP12 expression in only a small fraction of lung cells including goblet, club-like, vascular endothelial cells, and a range of immune cells, despite wide-spread tissue expression of spike protein antigen. Similar studies using in vitro infection also generated scant protein detection in cells with established virus replication. These results suggest that NSP12 may have diminished steady-state expression or extensive posttranslation modifications that limit antibody reactivity during SARS-CoV-2 replication.

Utility of liquid biopsy in diagnosing isolated cerebral phaeohyphomycosis: illustrative case.

BACKGROUND: Cladophialophora bantiana is a dematiaceous, saprophytic fungus and a rare but reported cause of intracranial abscesses due to its strong neurotropism. Although it predominantly affects immunocompetent individuals with environmental exposure, more recently, its significance as a highly lethal opportunistic infection in transplant recipients has been recognized. Successful treatment requires timely but often challenging diagnosis, followed by complete surgical excision. Next-generation sequencing of microbial cell-free DNA (cfDNA) from plasma is a novel diagnostic method with the potential to identify invasive fungal infections more rapidly and less invasively than conventional microbiological testing, including brain biopsy. OBSERVATIONS: The authors described the case of a recipient of a liver transplant who presented with seizures and was found to have innumerable ring-enhancing intracranial lesions. The Karius Test, a commercially available method of next-generation sequencing of cfDNA, was used to determine the causative organism. Samples from the patient's plasma identified C. bantiana 6 days before culture results of the surgical specimen, allowing optimization of the empirical antifungal regimen, which led to a reduction in the size of the abscesses. LESSONS: The authors' findings suggest that microbial cfDNA sequencing may be particularly impactful in improving the management of brain abscesses in which the differential diagnosis is wide because of immunosuppression.

Cutaneous leishmaniosis due to Leishmania mexicana in a cat treated with cryotherapy.

We report the novel use of cryosurgery to treat cutaneous feline leishmaniosis (FeL) in a domestic cat from mid-western Venezuela. Amastigotes, evident by microscopy in aspirates from the nodular, erythematous nose lesions, were identified as Leishmania mexicana by cytochrome b gene sequence analysis. Lesions resolved completely without relapse after 14 months.

Nous décrivons une nouvelle utilisation de la cryochirurgie pour traiter la leishmaniose féline cutanée (FeL) chez un chat domestique du centre-ouest du Venezuela. Les amastigotes, observés par microscopie dans les cytoponctions des lésions nodulaires et érythémateuses du nez, ont été identifiés comme Leishmania mexicana par analyse de la séquence du gène du cytochrome b. Les lésions ont complètement disparu sans rechute après 14 mois.

Describimos el uso novedoso de la criocirugía para tratar la leishmaniosis cutánea felina (FeL) en un gato doméstico del medio oeste de Venezuela. Los amastigotes, evidentes por microscopía en los aspirados de las lesiones nasales nodulares eritematosas, se identificaron como Leishmania mexicana mediante el análisis de la secuencia del gen del citocromo b. Las lesiones se resolvieron completamente sin recidiva tras 14 meses.

Neste estudo, relatamos a utilização inédita de criocirurgia para tratar leishmaniose felina cutânea (FeL) em um gato doméstico no centro-oeste da Venezuela. Amastigotas, evidentes à microscopia de aspirados da lesão nodular e eritematosa na região nasal, foram identificadas como Leishmania Mexicana por sequenciamento do gene do citocromo b. As lesões se resolveram completamente sem recidiva após 14 meses.

Robust clinical detection of SARS-CoV-2 variants by RT-PCR/MALDI-TOF multitarget approach.

The coronavirus disease 2019 (COVID-19) pandemic has sparked the rapid development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics. However, emerging variants pose the risk for target dropout and false-negative results secondary to primer/probe binding site (PBS) mismatches. The Agena MassARRAY® SARS-CoV-2 Panel combines reverse-transcription polymerase chain reaction and matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry to probe for five targets across N and ORF1ab genes, which provides a robust platform to accommodate PBS mismatches in divergent viruses. Herein, we utilize a deidentified data set of 1262 SARS-CoV-2-positive specimens from Mount Sinai Health System (New York City) from December 2020 to April 2021 to evaluate target results and corresponding sequencing data. Overall, the level of PBS mismatches was greater in specimens with target dropout. Of specimens with N3 target dropout, 57% harbored an A28095T substitution that is highly specific for the Alpha (B.1.1.7) variant of concern. These data highlight the benefit of redundancy in target design and the potential for target performance to illuminate the dynamics of circulating SARS-CoV-2 variants.

Relapsed Babesia microti Infection Following Allogeneic Hematopoietic Cell Transplantation in a Patient With B-cell Acute Lymphoblastic Leukemia: Case Report and Review of the Literature.

A patient with relapsed/refractory B-cell acute lymphoblastic leukemia developed babesiosis before allogeneic hematopoietic cell transplantation while on atovaquone for Pneumocystis jirovecii pneumonia prophylaxis. Despite receiving a prolonged course of atovaquone and azithromycin until whole-blood Babesia microti DNA was no longer detected by polymerase chain reaction, her post-transplant course was complicated by relapsed babesiosis. We investigate the potential host and parasite characteristics causing relapsing/persistent infection.

COVID-19 Associated Rhino-Orbital Mucormycosis Complicated by Gangrenous and Bone Necrosis-A Case Report from Honduras.

BACKGROUND: Mucormycosis is a life-threatening invasive fungal infection most commonly observed in immunocompromised patients. Throughout the COVID-19 pandemic, a growing number of Mucorales associated infections, now termed COVID-19 associated mucormycosis (CAM), have been reported. Despite an increase in fatality reports, no cases of rhino-orbital CAM complicated with gangrenous bone necrosis have been described in the literature to date. CASE: A 56-year-old male with a recent COVID-19 diagnosis developed rhino-orbital mucormycosis after 22 days of treatment with dexamethasone. Cultures and histopathological assessment of tissue biopsy confirmed the diagnosis. The patient survived after treatment with amphotericin B. CONCLUSIONS: Mucormycosis is an invasive fungal infection affecting mostly immunocompromised patients. Along with the COVID-19 pandemic, the inappropriate use of steroids, in addition to concurrent risk factors, such as diabetes, has led to an increase in the occurrence of these devastating mycoses, leading to the development of severe presentations and complications, as observed in many cases. Early diagnosis and prompt treatment are crucial in order to avoid dissemination and fatal outcomes.

Kawasaki disease seasonality in Venezuela supports an arbovirus infection trigger.

Kawasaki disease (KD) is an inflammatory disease primarily affecting infants and young children, whose etiology remains uncertain. Observational studies of the overlap between KD outbreaks and seasonal peaks of arboviral infections, suggest the possible role of these pathogens as triggers of KD. In Venezuela, regions with the highest reported arboviral infections simultaneously have the highest incidence of KD. One proposed explanation for this association involves the role of proinflammatory mediators, interleukin-1 (IL-1), IL-6, tumor necrosis factor, and vascular endothelial growth factor as mediators of coronary endothelial damage. The promotion of inflammation and tissue destruction by these cytokines is thought to contribute to the coronary endothelial damage experienced in KD. The utilization of overlapping KD and arboviral infection trends contribute to the comprehension of KD etiology, with improvements in diagnosis, prognosis and treatment.

Human Papillomavirus (HPV69/HPV73) Coinfection associated with Simultaneous Squamous Cell Carcinoma of the Anus and Presumed Lung Metastasis.

BACKGROUND: Human papillomaviruses (HPVs) have been linked to a variety of human cancers. As the landscape of HPV-related neoplasia continues to expand, uncommon and rare HPV genotypes have also started to emerge. Host-virus interplay is recognized as a key driver in HPV carcinogenesis, with host immune status, virus genetic variants and coinfection highly influencing the dynamics of malignant transformation. Immunosuppression and tissue tropism are also known to influence HPV pathogenesis. METHODS: Herein, we present a case of a patient who, in the setting of HIV positivity, developed anal squamous cell carcinoma associated with HPV69 and later developed squamous cell carcinoma in the lungs, clinically presumed to be metastatic disease, associated with HPV73. Consensus PCR screening for HPV was performed by real-time PCR amplification of the L1 gene region, amplification of the E6 regions with High-Resolution Melting Curve Analysis followed by Sanger sequencing confirmation and phylogenetic analysis. RESULTS: Sanger sequencing of the consensus PCR amplification product determined that the anal tissue sample was positive for HPV 69, and the lung tissue sample was positive for HPV 73. CONCLUSIONS: This case underscores the importance of recognizing the emerging role of these rare "possibly carcinogenic" HPV types in human carcinogenesis.

Primary cutaneous carcinosarcoma: insights into its clonal origin and mutational pattern expression analysis through next-generation sequencing.

Primary cutaneous carcinosarcoma is a rare biphenotypic neoplasm exhibiting both epithelial and sarcomatous elements. Even though its origin and biological aspects remain poorly understood, it has been postulated that this tumor may arise from progenitor cells, which subsequently differentiate into distinct tumor components. We have investigated the histological and immunohistochemical staining patterns of a cutaneous carcinosarcoma case, as well as its ultrastructural aspects. In addition, sarcomatous and epithelial tumor components were separated by laser capture microdissection and subjected to targeted, high-depth, next-generation sequencing of a 46-cancer gene panel to asses the gene mutational pattern amongst both components. There were transitional cells at the epithelial/mesenchymal transition that labeled with putative progenitor cell markers (K19, c-kit, CD34 and Bcl-2). There was shared reactivity to antibodies directed against the progenitor cell marker EpCAM (epithelial cell adhesion molecule) in both components. Ultrastructurally, individual cells were demonstrated to have overlapping features of epithelial and mesenchymal differentiation. The mutational analysis revealed point mutations in exon 5 of TP53, which were identical in both the epithelial and sarcomatous components, and which were concordant with p53 expression at a tissue level. The aforementioned histological, ultrastructural, immunohistochemical and mutational pattern is strongly suggestive of a common clonal origin to the distinct elements of this tumor.

Manifestaciones cardiovasculares de la toxocariasis humana / Cardiovascular manifestations of human toxocariasis

La toxocariasis es una infección parasitaria producida por un helminto que en el ser humano no alcanza su estadio adulto. El hombre es para sus especies, Toxocara canis y Toxocara cati, un hospedador paraténico. Dicha infección puede producir el síndrome de larva migrans visceral, el síndrome de larva migrans ocular y la toxocariasis inaparente. En el síndrome de larva migrans visceral el compromiso de órganos puede incluir hígado, pulmón, piel, sistema nervioso, musculoesquelético, riñón y corazón. Sobre este último, cada vez se reconoce más la importancia que pueden tener las manifestaciones cardiovasculares de la toxocariasis y la relevancia clínica de considerarlas. En el presente artículo, haciendo una búsqueda sistemática de información, se revisan los principales aspectos clinicopatológicos de las manifestaciones cardiovasculares de la toxocariasis incluyendo su fisiopatología, hallazgos de laboratorio, diagnóstico y opciones terapéuticas, con el objeto de llamar la atención acerca de la importancia de esta zoonosis y su relevancia para la medicina cardiovascular en adultos y en niños.

Toxocariasis is a parasitic infection produced by helminths that cannot reach their adult stage in humans. For their etiological species (Toxocara canis and Toxocara cati), man is a paratenic host. Infection by such helminths can produce a variety of clinical manifestations, such as: visceral larvae migrans syndrome, ocular larvae migrans syndrome and covert toxoca-riasis. In the visceral larvae migrans syndrome, the organs that are mainly involved include liver, lungs, skin, nervous system, muscles, kidneys and the heart. Regarding the latter, the importance of cardiovascular manifestations in toxocariasis, as well as its clinical relevance, has increasingly begun to be recognized. The current article is based on a systematic information search, focused mainly on the clinical and pathological aspects of cardiovascular manifestations in toxocariasis, including its pathophysiology, laboratory findings, diagnosis and therapeutical options, with the objective of highlighting its importance as a zoonosis and its relevance to the fields of cardiovascular medicine in adults and children.

Translocation renal cell carcinomas in adults: a single-institution experience.

Translocation renal cell carcinoma is a newly recognized subtype of renal cell carcinoma (RCC) with chromosomal translocations involving TFE3 (Xp11.2) or, less frequently, TFEB (6p21). Xp11 translocation RCC was originally described as a pediatric neoplasm representing 20% to 40% of pediatric RCCs, with a much lower frequency in the adult population. TFEB translocation RCC is very rare, with approximately 10 cases reported in the literature. Here, we describe the clinicopathologic features of adult translocation RCC from a single institution. Using tissue microarray, immunohistochemistry, cytogenetic examination, and fluorescence in situ hybridization, we identified 6 (∼5%) cases of TFE3 translocation RCC and 1 (<1%) case of TFEB translocation RCC in 121 consecutive adult RCC cases between 2001 and 2009. Our results suggest that weak TFE3 staining of a significant proportion of RCC cases may be because of expression of the full-length TFE3 protein rather than the chimeric fusion protein resulting from chromosomal translocation.

Mixed adenoneuroendocrine carcinoma (MANEC) of the gallbladder: a possible stem cell tumor?

A 48 year-old African American woman presented to her physician complaining of a rapidly evolving epigastric and right upper quadrant abdominal pain. A PET-CT of the abdomen and pelvis demonstrated hypermetabolic, polypoid masses within the gallbladder and several tumors in the left lobe of the liver for which she underwent diagnostic laparoscopy. The gallbladder revealed a 3.5 × 3.3 × 2.4 tan-brown exophytic mass located at the fundus and growing into the lumen with multiple contiguous papillary projections arising from the mucosal surface. A concurrent large cell neuroendocrine carcinoma and papillary adenocarcinoma of the gallbladder was revealed histologically. There was shared reactivity to antibodies directed against the distinct antigens for each morphological component with transitional tumor cells (of both histological components) located at the areas where the two tumor types merged, revealing common immunoreactivity for carcinoembryonic antigen, cancer antigen 19-9, keratin 19, c-kit (cluster of differentiation protein 117 (CD117)) and epithelial cell adhesion molecule. Ultrastructurally, individual cells were demonstrated to have overlapping features of neuroendocrine and glandular differentiation. The aforementioned histological, ultrastructural and immunohistochemical profile is strongly suggestive of a biphenotypic stem/progenitor cell tumor of the gallbladder.

Lobomycosis in Venezuela.

Lobomycosis is a chronic dermal infection that presents a wide spectrum of clinical- dermatological manifestations, mainly characterized by the development of keloid lesions as well as nodular, verrucoid and sometimes ulcerous forms. The etiological agent at an international level, according to the consensus nomenclature, has been called Loboa loboi, even though recently it has been accommodated as Lacazia loboi. The present review extensively covers the clinical-epidemiological aspects as well as the most outstanding historical aspects, including the Venezuelan experience and the presentation of two new cases, which substantiate the Amazon basin as an endemic area for the disease.