Challenging Diagnosis of Streptococcus intermedius-Associated Empyema in an Immunocompetent Adult: A Case Report and Literature Review.

The significance of Streptococcus intermedius in infectious diseases, especially pleural infections, is gaining recognition. While traditional risk factors like dental procedures and immunosuppression remain pivotal in differential diagnosis, there is an emerging recognition of unconventional clinical presentations and risk factors linked to infections by S. intermedius. This shift compels medical professionals to broaden their diagnostic and therapeutic strategies, underscoring the intricate and evolving nature of managing infections associated with this opportunistic bacterium. We describe the case of a 48-year-old immunocompetent woman with untreated hypertension who experienced a 15-day episode of right-sided chest pain, which worsened with a sudden onset of dyspnea, yet her daily activities remained unaffected. Physical examination suggested a pleuropulmonary syndrome due to significant pleural effusion, with a computed tomography (CT) scan of the lungs revealing about 50% effusion on the right side. Laboratory tests indicated elevated inflammatory markers. Ultrasound-guided thoracentesis extracted purulent fluid compatible with empyema, necessitating the placement of a pleural drain and multiple pleural cavity lavages using alteplase, which led to the removal of substantial infected fluid. Culture of the pleural fluid identified S. intermedius, which was pansusceptible. Treatment with intravenous ceftriaxone was administered, resulting in a favorable clinical outcome. This case highlights the critical nature of recognizing atypical clinical presentations and managing complex bacterial infections in the pleural space.

Unusual Presentation of Nocardiosis With Pleural Effusion in an Immunocompetent Host.

Nocardiosis is a disease caused by gram-positive, catalase-positive, rod-shaped bacteria that stain weakly on a Gram stain. It usually affects the lungs and skin but can cause disseminated infections. Nocardia has 85 species, ranging from nonpathogenic to pathogenic. Nocardia is an opportunistic organism that causes infections in the immunocompromised; however, 7% of the immunocompetent population has suffered from Nocardia infection. This case report highlights an unusual occurrence of pulmonary nocardiosis in a 31-year-old woman with a normal immune system. She was initially treated as an outpatient for what appeared to be community-acquired pneumonia. However, her condition deteriorated, ultimately revealing a substantial right pleural effusion with loculation and adjacent compressive atelectasis affecting a significant portion of her right middle and lower lung lobes, as detected by a CT scan followed by pleural fluid analysis which confirmed the infection. By sharing this experience, we aim to contribute to the collective knowledge of medical professionals and improve the accuracy of diagnosis and treatment.

Pulmonary scedosporiosis in an intractable immunocompetent host: A case report and literature review.

Pulmonary scedosporiosis is a rare pulmonary infection that often presents with nonspecific symptoms and radiological findings. In this report, we present a case of localized pulmonary scedosporiosis in an immunocompetent patient and analyze a total of 25 immunocompetent patients with pulmonary scedosporiosis. Through this case and the literature, we highlight the importance of considering pulmonary scedosporiosis in patients with nonspecific clinical symptoms and radiological findings resembling aspergilloma. This case and the literature further emphasize the significance of surgical intervention. Regardless of the use of antifungal drugs, surgery should be conducted as soon as possible.

Visceral Leishmaniasis in Immunocompetent Hosts in Brescia: A Case Series and Analysis of Cytokine Cascade.

Visceral leishmaniasis (VL) is a parasitic zoonosis caused by Leishmania spp. that usually manifests itself in immunocompromised subjects. It is a rare and neglected disease, and it is not endemic in the province of Brescia (Italy). Three cases of human VL occurred in Brescia from October to December 2021 in immunocompetent patients. We evaluated the patients looking for signs of underlying immunodeficiencies and conducted further epidemiological evaluations in the province of Brescia without success. An analysis of the sera levels of the main cytokines involved in the immune response to VL was performed. All patients presented a significant augmentation of CXCL-10, CCL-4, and IL-6. The patients tested during the acute phase showed an elevation of IL-1α, IL-5, IL-10, and IL-12, while in the recovery phase, higher levels of TNF-α and IL-7 were detected. Altogether, a predominant activation of the T-helper-2 pathway emerged during the acute phase of the parasite infection, while the cytokines associated with the T-helper-1 pathway were less represented. This imbalanced immune response to the parasite infection might play a crucial role in the development of VL in immunocompetent patients.

Primary oral histoplasmosis in an immunocompetent host masquerading as malignancy.

Histoplasma capsulatum is known to cause deep mycotic infections, the primary site being pulmonary, and may disseminate in immunosuppressed patients. Oral presentation is usually a part of disseminated disease however may rarely occur as an isolated event. Extensive literature search has shown that only 17 cases of primary oral histoplasmosis in immunocompetent hosts have been reported from India to date. We hereby report a rare case of primary oral histoplasmosis in a middle-aged, non-diabetic, and HIV-negative patient masquerading as malignancy.

Primary Cutaneous Cryptococcosis in an Immunocompetent Patient: Diagnostic Workflow and Choice of Treatment.

Cryptococcosis is an opportunistic infection in immunocompromised patients, involving mainly the lungs and central nervous system; however, the skin, eyes and genitourinary tract could also be involved as secondary sites of infection. Primary cutaneous cryptococcosis (PCC) is a distinct clinical entity that can occur in both immunocompetent and -compromised patients, usually trough skin injury. In immunocompetent patients, it is a very rare infection, presenting with non-specific clinical pictures and being challenging to diagnose. Herein, we present the case of an immunocompetent man with PCC due to Cryptococcus neoformans on his right forearm. PCC was diagnosed by a histological and cultural examination. Causes of concomitant immunosuppression were ruled out. A secondary cutaneous cryptococcosis was excluded with careful investigations. Therapy with oral fluconazole for three months was successfully performed, without evidence of recurrence in the following six months. Complete clinical recovery was achieved after three months of oral antifungal therapy, suggesting that longer courses of treatment could be avoided when faced with PCC in immunocompetent patients.

Acute Cryptococcal Meningitis in a Patient With Idiopathic CD4 Lymphocytopenia: A Rare Clinical Entity.

Cryptococcal meningitis is a known cause of opportunistic infection in immunocompromised patients, especially those with AIDS. Very few cases exist in literature where cryptococcal meningitis is seen in patients without evidence of HIV infection. Here, we describe a case of an elderly woman presenting with clinical features of meningitis. Our patient tested positive for cryptococcal antigen (CRAg) in the CSF and growth of Cryptococcus neoformans was obtained in CSF culture. Further laboratory investigations revealed CD4 lymphocytopenia (233 cells/µl) in the absence of HIV infection. When we checked the CD4 count, beyond a period of six weeks, it was reported to be low, which confirmed our diagnosis of idiopathic CD4 lymphocytopenia (ICL). She was successfully treated with amphotericin B along with flucytosine for two weeks and discharged on maintenance antifungal therapy for eight weeks. This case emphasizes the need to maintain a high index of suspicion and consider the possibility of opportunistic infections even in the absence of HIV infection for timely diagnosis and treatment.

Vertebral discitis caused by Salmonella enterica serovar Montevideo infection.

Salmonellosis is a common cause of foodborne illness worldwide, manifesting as non-invasive non-typhoidal salmonellosis, invasive non-typhoidal salmonellosis, and typhoid fever. It also rarely presents as Salmonella osteomyelitis in children with hemoglobinopathies and immunocompromised adults and even rarer osteomyelitis in an immunocompetent host without significant risk factors. Our case is of a 38-year-old immunocompetent male without significant risk factors presented with biopsy proven Salmonella vertebral discitis due to exposure to contaminated and undercooked poultry. It illustrates the importance of thorough and complete history taking even in immunocompetent patients and early recognition with prompt targeted treatment of Salmonella osteomyelitis/discitis to prevent unfavorable outcomes.

An unusual case of disseminated cryptococcosis in an immunocompetent host presenting with verrucous skin lesions.

Disseminated cryptococcosis, commonly linked to immunocompromised conditions like HIV infection, is exceedingly rare in immunocompetent individuals. This case report presents a rare case of disseminated cryptococcosis in an immunocompetent patient, who manifested with fever, weight loss, neurological manifestations, and distinct verrucous skin lesions. Mycological cultures and histopathological assessments were conducted, leading to the identification of Cryptococcus neoformans var. gattii within both lung and skin biopsies. This case highlights the significance of considering this yeast infection within immunocompetent individuals and the necessity for promptly initiating appropriate antifungal therapy to enhance patient outcomes.

COVID-19-associated pulmonary aspergillosis in immunocompetent patients: a virtual patient cohort study.

The opportunistic fungus Aspergillus fumigatus infects the lungs of immunocompromised hosts, including patients undergoing chemotherapy or organ transplantation. More recently however, immunocompetent patients with severe SARS-CoV2 have been reported to be affected by COVID-19 Associated Pulmonary Aspergillosis (CAPA), in the absence of the conventional risk factors for invasive aspergillosis. This paper explores the hypothesis that contributing causes are the destruction of the lung epithelium permitting colonization by opportunistic pathogens. At the same time, the exhaustion of the immune system, characterized by cytokine storms, apoptosis, and depletion of leukocytes may hinder the response to A. fumigatus infection. The combination of these factors may explain the onset of invasive aspergillosis in immunocompetent patients. We used a previously published computational model of the innate immune response to infection with Aspergillus fumigatus. Variation of model parameters was used to create a virtual patient population. A simulation study of this virtual patient population to test potential causes for co-infection in immunocompetent patients. The two most important factors determining the likelihood of CAPA were the inherent virulence of the fungus and the effectiveness of the neutrophil population, as measured by granule half-life and ability to kill fungal cells. Varying these parameters across the virtual patient population generated a realistic distribution of CAPA phenotypes observed in the literature. Computational models are an effective tool for hypothesis generation. Varying model parameters can be used to create a virtual patient population for identifying candidate mechanisms for phenomena observed in actual patient populations.

Isolated pleural mucormycosis in an immunocompetent patient: a case report.

Pulmonary mucormycosis is an uncommon, difficult-to-diagnose disease with currently no suitable treatments. It is associated with hematological malignancies, diabetes, and immunosuppression. Case presentation: We report a 16-year-old boy who developed pleural mucormycosis for unknown reasons. The patient presented to our hospital because of fever, chills, weakness, lethargy, loss of appetite, pleuritic chest pain, and shortness of breath. Histopathological testing ultimately diagnosed mucormycosis. Discussion: Pulmonary mucormycosis is a potentially fatal infection with a challenging clinical presentation that requires prompt diagnosis. Diagnosis of pleural mucormycosis was verified by histopathological analysis of pleural fluid and pleural tissue biopsy. Conclusion: This study emphasizes the relevance of histological examination in detecting mucormycosis, which will aid in early management by highlighting the difficulty of diagnosis.

Intracranial Myroides odoratimimus Infection After EVD Successfully Treated with Intravenous Plus Intraventricular Tigecycline: A Case Report.

Intracranial infections are the most serious and common postoperative complications with significant mortality and morbidity. Myroides odoratimimus (M. odoratimimus), a Gram-negative environmental species and an opportunistic microorganism, predominantly infects immunocompromised individuals. Limited clinical experiences and documented multidrug resistance have resulted in a scarcity of data on the treatment of M. odoratimimus infections. As far as we know, this is the first reported case of an intracranial M. odoratimimus infection with external ventricular drains (EVD) that was effectively treated with a combination of intravenous and intraventricular tigecycline in an immunocompetent adult host.

Clinical Spectrum, Radiological Findings, and Outcomes of Severe Toxoplasmosis in Immunocompetent Hosts: A Systematic Review.

BACKGROUND: Accumulating evidence suggests that toxoplasmosis in immunocompetent hosts can be severe and life-threatening. METHODS: We performed a systematic review of severe toxoplasmosis cases in immunocompetent patients to gain insight into the epidemiology, clinical characteristics, radiological findings, and outcomes of these cases. We classified severe toxoplasmosis as cases with the symptomatic involvement of target organs (the lungs, central nervous system (CNS), and heart), disseminated disease, prolonged disease (>3 months), or a fatal outcome. Our primary analysis focused on cases published from 1985-2022 to avoid confounding with cases in AIDS patients. RESULTS: We identified 82 pertinent articles (1985-2022) with a total of 117 eligible cases; the top five countries for these cases were French Guiana (20%), France (15%), Colombia (9%), India (9%), and Brazil (7%). Overall, 44% (51/117) of cases had pulmonary involvement, 39% (46/117) CNS, 31% (36/117) cardiac, 24% (28/117) disseminated disease, 2% (2/117) had prolonged disease, and 8% (9/117) of patients died. More than one organ was involved in 26% (31/117) of cases. Eighty-four percent (98/117) of cases occurred in the context of a recent acute primary Toxoplasma infection; for the remaining, the exact timing of infection was unclear. Genotyping data were very sparse. Among those reporting genotyping data, 96% (22/23) were caused by atypical non-type II strains; one case was caused by a type-II strain. Only half of the cases reported risk factors. The most common risk factors were eating raw/undercooked meat or eating game meat (47% (28/60)), drinking untreated water (37% (22/60)), or living in a toxoplasmosis high-prevalence area (38% (23/60)). For the 51 pulmonary cases, the main clinical presentation was pneumonia or pleural effusions in 94% (48/51) and respiratory failure in 47% (24/51). For the 46 CNS cases, the main clinical presentation was encephalitis in 54% (25/46), meningitis in 13% (6/46), focal neurologic findings in 24% (11/46), cranial nerve palsies in 17% (8/46), Guillain-Barre syndrome or Miller Fisher syndrome in 7% (3/46), and Brown-Sequard syndrome in 2% (1/46) of cases; more than one clinical manifestation could also be present. Among the 41 CNS cases reporting the CNS imaging findings, 68% (28/41) had focal supratentorial lesions and 7% (3/41) had focal infratentorial lesions. Brain abscess-like/mass-like lesions were seen in 51% (21/41) of cases. For the 36 cardiac cases, the main clinical presentation was myocarditis in 75% (27/36), pericarditis in 50% (18/36), heart failure and/or cardiogenic shock in 19% (7/36), and cardiac arrhythmias in 22% (8/36); more than one manifestation could also be present. Illness was critical in 49% (44/90) of cases intensive care unit care was needed in 54% (29/54) of cases among those reporting this information, and 9 patients died. CONCLUSION: The diagnosis of severe toxoplasmosis in immunocompetent hosts can be challenging. Toxoplasmosis should be considered in the differential diagnosis of immunocompetent patients presenting with severe illness of unclear etiology with pulmonary, cardiac, CNS, or multiorgan involvement/failure, or prolonged febrile illness, even in the absence of common exposure risk factors or common manifestations of toxoplasmosis (e.g., fever, mononucleosis-like illness, lymphadenopathy, and chorioretinitis). Fatal outcomes can also rarely occur in immunocompetent patients. Prompt initiation of anti-Toxoplasma treatment can be lifesaving.

Cytomegalovirus and Hemolytic Anemia in an Immunocompetent Adult.

Hemolytic anemia is an increasingly recognized complication of cytomegalovirus (CMV) infection in immunocompetent patients. Although it is thought to be immune-mediated, other mechanisms have been proposed. The decision to treat is controversial but it may include antiviral and immunosuppressive therapy. We report a case of CMV-induced hemolytic anemia in a previously healthy 55-year-old woman. The patient presented with asthenia and choluria, and laboratory tests showed severe anemia with hyperbilirubinemia and elevated lactate dehydrogenase. A diagnosis of hemolytic anemia was made. Structural, enzymatic, toxic, pharmacological, and neoplastic causes were excluded. The CMV immunoglobulin M was positive, with a negative direct antiglobulin test. The patient had an improvement in clinical and laboratory status without any treatment, and two months later she had a full recovery of the anemia. This case illustrates that CMV infection might be associated with severe organ damage in immunocompetent patients but has an overall good prognosis without any directed treatment.

Onchycobacter anthropi Pyomyositis in Immunocompetent Patient: Case Report.

Introduction: Ochrobactrum anthropi is an unusual low virulence emerging pathogen that rarely causes orthopedic infection and its clinical picture is not well described. It usually causes infection in immunocompromised hosts with indwelling catheters or foreign bodies, such as the central venous catheters. Case Report: We reported a case of O. anthropi pyomyositis in a 22-year-old immunocompetent male patient not on any invasive procedure presented with raised temperature, left shoulder pain, and restriction of movements. Diagnosis was confirmed with the help of MRI and biopsy. He was successfully managed with surgical debridement and appropriate antibiotics. Conclusion: Our case highlights the ability of O. anthropi to cause pyomyositis in immunocompetent individuals and its relevance in the field of orthopaedic infection.

Rare cardiac complication of toxoplasmosis in immunocompetent host.

Myocarditis is a rare complication of toxoplasmosis, especially in immunocompetent individuals. We present a case of a 28-year-old man with a history of fever and chest pain suggestive of myocarditis. Fever, along with lymphadenopathy, electrocardiography, imaging, and serologic testing, showed Toxoplasma gondii as the probable etiology. An excellent response to treatment confirmed the diagnosis.

Genetic and Drug Inhibition of LDH-A: Effects on Murine Gliomas.

The effects of the LDH-A depletion via shRNA knockdown on three murine glioma cell lines and corresponding intracranial (i.c.) tumors were studied and compared to pharmacologic (GNE-R-140) inhibition of the LDH enzyme complex, and to shRNA scrambled control (NC) cell lines. The effects of genetic-shRNA LDH-A knockdown and LDH drug-targeted inhibition (GNE-R-140) on tumor-cell metabolism, tumor growth, and animal survival were similar. LDH-A KD and GNE-R-140 unexpectedly increased the aggressiveness of GL261 intracranial gliomas, but not CT2A and ALTS1C1 i.c. gliomas. Furthermore, the bioenergetic profiles (ECAR and OCR) of GL261 NC and LDH-A KD cells under different nutrient limitations showed that (a) exogenous pyruvate is not a major carbon source for metabolism through the TCA cycle of native GL261 cells; and (b) the unique upregulation of LDH-B that occurs in GL261 LDH-A KD cells results in these cells being better able to: (i) metabolize lactate as a primary carbon source through the TCA cycle, (ii) be a net consumer of lactate, and (iii) showed a significant increase in the proliferation rate following the addition of 10 mM lactate to the glucose-free media (only seen in GL261 KD cells). Our study suggests that inhibition of LDH-A/glycolysis may not be a general strategy to inhibit the i.c. growth of all gliomas, since the level of LDH-A expression and its interplay with LDH-B can lead to complex metabolic interactions between tumor cells and their environment. Metabolic-inhibition treatment strategies need to be carefully assessed, since the inhibition of glycolysis (e.g., inhibition of LDH-A) may lead to the unexpected development and activation of alternative metabolic pathways (e.g., upregulation of lipid metabolism and fatty-acid oxidation pathways), resulting in enhanced tumor-cell survival in a nutrient-limited environment and leading to increased tumor aggressiveness.

A Stroll Through the History of Monoxenous Trypanosomatids Infection in Vertebrate Hosts.

The Trypanosomatidae family encompasses unicellular flagellates and obligate parasites of invertebrates, vertebrates, and plants. Trypanosomatids are traditionally divided into heteroxenous, characterized by the alternation of the life cycle between an insect vector and a plant or a vertebrate host, including humans being responsible for severe diseases; and monoxenous, which are presumably unique parasites of invertebrate hosts. Interestingly, studies reporting the occurrence of these monoxenous trypanosomatids in humans have been gradually increasing, either associated with Leishmania co-infection, or supposedly alone either in immunocompromised or even more sporadically in immunocompetent hosts. This review summarizes the first reports that raised the hypothesis that monoxenous trypanosomatids could be found in vertebrate hosts till the most current reports on the occurrence of Crithidia spp. alone in immunocompetent human patients.

Clinical Features of Pulmonary Nocardiosis in Patients with Different Underlying Diseases: A Case Series Study.

Objective: To investigate the clinical features of pulmonary nocardiosis (PN) in patients with different underlying diseases. Methods: Clinical, imaging, treatment and prognosis data from patients diagnosed with PN from July 2011 to June 2021 at the First Affiliated Hospital, Zhejiang University School of Medicine were collected and analyzed. According to different underlying diseases, patients were grouped into immunocompromised host (ICH) group and immunocompetent host (ICO) group, and clinical characteristics were compared between the two groups. Results: There were 64 patients with PN, including 42 males, aged from 21 to 86 (57.1 ± 15.7) years. The most common clinical manifestations were cough, expectoration, fever. There were 41 cases in the ICH group and 23 cases in the ICO group. There were 11 cases with underlying pulmonary diseases in the ICH group, including 2 cases of bronchiectasis, 4 cases of chronic obstructive pulmonary disease (COPD), etc. There were 11 cases of underlying pulmonary basic diseases in ICO group, including 7 cases of bronchiectasis and COPD, 1 case of bronchiectasis, 1 case of COPD, etc. The proportion of patients with bronchiectasis and COPD in the ICO group was significantly higher (P < 0.05). Extrapulmonary nocardiosis infection occurred in 6 patients of the ICH group. During the period of hospitalization, 87.0% patients in ICO group received SMZ/TMP therapy, 73.2% of patients in ICH group received two drug combination therapy. In the ICH group, mortality at 28 days was 14.6% and 8.7% in the ICO group. Conclusion: PN mainly occurred in ICH patients, but also occurred in the ICO cases to a lesser extent, especially in patients with bronchiectasis and/or COPD. Complicated with extrapulmonary infections mainly occurred in ICH population and combination of two antibiotics was often used in ICH group. The case fatality rates were 14.6% in ICH and 8.7% in ICO cases, respectively.

Primary Oral Histoplasmosis in Immunocompetent Host: Case Series with Review of Literature.

Histoplasmosis, a systemic mycosis caused by Histoplasma capsulatum manifests clinically in immunocompromised subjects as acute or chronic pulmonary infection or as a progressive disseminated disease. In oral region it clinically presents as multiple, granular and painful ulcers or verrucous growth. It is rare to find primary oral lesion of histoplasmosis in immunocompetent patient free from systemic disease. In presence of any unusual oral lesion possibility of Histoplasmosis should be considered and prompt diagnosis be attained with exclusion of false negative results as non-specific manifestation of disease may lead to gruesome misdiagnosis of lesion and inadequate treatment. In the present paper two cases of oral histoplasmosis in immunocompetent host have been discussed along with updated review of literature.