Histopathological Pattern of Fungal Infections Seen in Usmanu Danfodiyo University Teaching Hospital Sokoto from 2014 To 2018

Introduction: Fungal infection is a common manifestation in this part of the country and worldwide. It is essential to define the epidemiology of fungal infection in a particular environment. Aim: This study aims to analyze the diagnosis of fungal infection carried out in patients attending the histopathology department (UDUTH) Sokoto from 2014 to 2018. Method: This study is a retrospective study of all fungal infection biopsies carried out from 2014 – 2019 in Usmanu Danfodiyo University Teaching Hospital, Sokoto, northwestern Nigeria, a referral centre for the neighbouring northern states Kebbi and Zamfara. Ethical clearance was obtained from the ethical committee of UDUTH, data was collected from histological report cards and analyze manually. Some tissue blocks of the case were retrieved to confirm the diagnosis. A total of 66 requests for fungal diagnosis were received from January 2014 to December 2018, which represent about 0.7% of the total biopsies received over the study period. Result: Out of the 66 of request for fungal diagnosis 32(48.5%) were fungal positive. Subcutaneous mycosis was the most frequent fungal infection with a frequency of 18(56.25%). Males were more frequently affected than females with the frequencies of 18(56.25%) and 14 (43.75%) respectively.

Analysis of biofilm formation by Sporothrix schenckii

The development of mature biofilms is an aid in numerous aspects of the life cycle of fungi. It is well known that Sporothrix schenckii complex causes a benign subcutaneous mycosis, but recent studies have suggestedthat biofilm formation may be one of the important factors involved in its virulence. Here we report the study of the biomass organization and a model of the stages of S. schenckii biofilm development: adsorption, active adhesion, microcolony formation, maturation, and dispersal of biofilm fragments. During the development, the biofilm is surrounded by extracellular matrix, which contains glycoprotein (mannose rich), carbohydrates, lipids, and nucleic acid. In addition, the extracellular DNA increases in extracellular matrix as a key component to structural integrity and antifungal resistance. The study of S. schenckii biofilm contributes to a better understanding of growth biofilm and physiology, adding new insights into the mechanisms of virulence and persistence of pathogenic microorganisms.

Rhinofacial Conidiobolomycosis: A Case Series and Review of the Literature

Conidiobolomycosis is an uncommon, chronic, localized subcutaneous mycosis primarily affecting rhinofacial region. It is reported mainly from tropical and subtropical countries. The condition is underreported due to the lack of clinical suspicion and usually mismanaged. This rare mycosis is due to the genus Conidiobolus within the order Entomophthorales of class Zygomycetes. Here we present 3 cases of rhinofacial conidiobolomycosis in otherwise healthy adults from different parts of Sri Lanka over 1-year period. All patients had disfiguring subcutaneous lesions in the rhinofacial area. The diagnoses were based on isolation of Conidiobolus coronatus in clinical specimens.

Fonsecaea pedrosoi conidia and hyphae activate neutrophils distinctly: Requirement of TLR-2 and TLR-4 in neutrophil effector functions

Chromoblastomycosis is a chronic and progressive subcutaneous mycosis caused mainly by the fungus Fonsecaea pedrosoi. The infection is characterized by erythaematous papules and the histological sections demonstrating an external layer of fibrous tissue and an internal layer of thick granulomatous inflammatory tissue containing mainly macrophages and neutrophils. Several groups have been studying the roles of the innate and adaptive immune systems in F. pedrosoi infection; however, few studies have focused on the role of neutrophils in this infection. In the current study, we verified the importance of murine neutrophils in the killing of F. pedrosoi conidia and hyphae. We demonstrate that phagocytosis and reactive oxygen species during infection with conidia are TLR-2 and TLR-4-dependent and are essentials for conidial killing. Meanwhile, hyphal killing occurs by NETs formation, in a TLR-2, TLR-4 and ROS-independent manner. In vivo experiments showed that TLR-2 and TLR-4 are also important in Chromoblastomycosis infection. TLR-2KO and TLR-4KO animals had lower levels of MIP-2 and KC chemokines and impaired neutrophil migration to the infected site. These animals also had higher fungal loads during infection with F. pedrosoi conidia, confirming that TLR-2 and TLR-4 are essential receptors for F. pedrosoi recognition and immune system activation. Therefore, this study demonstrated for the first time that neutrophils activation during F. pedrosoi is conidial or hyphal-specific, with TLR-2 and TLR-4 being essential during conidial infection but unnecessary for hyphal killing by neutrophilsAuthor SummaryChromoblastomycosis (CBM) is a chronic and progressive subcutaneous mycosis that affects mainly low-income individuals, such as farm workers. CBM have been diagnosed all over the world, but the majority of cases were diagnosed in tropical and subtropical climate countries. The treatment is difficult and involves the combination of antifungal prescriptions, cryo/heat-therapy and, in some cases, surgery to remove all the infected tissue. The treatment is long (at least 6 months) and expensive, leading to a high rate of treatment dropout and disease relapse. However, the understanding of pathogen-host interaction is far from being elucitaded. Our understanding is that this pathogen-host interaction in CBM needs to be uncovered so a different and more effective treatment could be proposed to help those patients that are struggling against this chronic infection. Therefore, our study shed a light in neutrophils and innate immune response against this fungal infection, showing the neutrophils capacity to kill Fonsecaea pedrosoi conidia and hifa, showing the importance of toll-like receptors 2 and 4 in the neutrophil fungicidal capacity against F. pedrosoi conidia but not hyphae. Therefore this work help to the better understanding of how our organism fights back in the CBM infection.

Sporotrichosis in a FeLV seropositive feline – case report

Sporotrichosis is a subcutaneous mycosis caused by the fungi of the Sporothrix schencki complex. The disease affects men and animals and is particularly severe in cats. The infection is typically acquired by traumatic inoculation of the fungus through scratches and bites from infected animals. Prognosis is worse in patients with immunodepressive diseases such as FeLV, and when administration of treatment is challenging. We report the therapeutic management of sporotrichosis in a cat seropositive for FeLV. Treatment resulted in regression of lesions and marked improvement of clinical signs.