Ophthalmic manifestations in patients recovered from COVID-19 in Mexico

INTRODUCTION AND OBJECTIVES

Although the ophthalmic manifestations appear to be associated with the coronavirus disease 2019 (COVID-19), there is not enough evidence. Hence, the aim of this study was to determine the various types and frequency of ophthalmic manifestations in patients recovered from SARS-CoV-2 infection in Mexico.

MATERIAL AND METHODS

This retrospective, observational and descriptive study included all patients recovered from SARS-CoV-2 infection attending the tertiary level hospital of Mexican Social Security Institute (IMSS) from June 2020 to June 2022. During the hospital admission of patients, the demographic data such age, name, gender was recorded. Ophthalmologic examination was performed under torchlight by an ophthalmologist in the Department of Ophthalmology from IMSS. Data was compiled and statistically analyzed using Fisher's exact test and Spearman correlation.

RESULTS

A total of 3,081 SARS-CoV-2-positive patients were recorded, of which 318 (10.32%) met the inclusion criteria. Of them, 21 (6.60%) had ophthalmic manifestations and the female-to-male ratio was 1.6:1. The mean age (±SD) was 47.95 ± 15.27 years and the median (interquartile range) time from the diagnosis of COVID-19, as defined by positive SARS-CoV-2 RT-PCR testing, to detection of the ophthalmic manifestation was 31 (142) days. The most common ocular manifestation was orbital mucormycosis (23.80%). Interestingly, the presence of ophthalmic manifestations was not associated with severe COVID-19 (p = 0.665).

CONCLUSIONS

The ophthalmic manifestations are infrequent in patients recovered from severe COVID-19. Nevertheless, further large sample studies are needed to confirm these findings.

Oral involvement in mucormycosis. A retrospective study of 55 cases

INTRODUCTION

Mucormycosis with oral involvement (OIM) is a rare opportunistic and lethal mycosis, which has increased in the last decade and is generally associated with uncontrolled diabetes and neutropenia.

METHODS

A retrospective study of cases with OIM was carried out in a tertiary-care center. Mycological and histological examinations were performed, and the isolated organisms were identified by morphology and molecular biology.

RESULTS

Fifty-five OIM patients were included, with a median age of 38 years (61.8% males). The most frequent associated disease was type-2 diabetes mellitus (61%), followed by neutropenia due to acute lymphocytic leukemia (27%). The main presentation was palatal and mandibular ulcers (92.7%) and, to a lesser extent, gingival and lingual necrosis. The diagnosis was established by mycological and histopathological studies. The most frequent fungi isolated was Rhizopus arrhizus (67.2%).

CONCLUSION

OIM is a rapidly progressing disease, therefore, an early diagnosis and the proper control of predisposing factors is necessary, and consequently, contributing to improve the outcome of mucormycosis.

[Mucormycosis: Current and future management perspective]

Infections caused by mucorales, with an increasing incidence after candidiasis and aspergillosis, are characterized by the fast angioinvasion of blood vessels and invasion of neighboring organs or structures. Mucorales most commonly cause rhinocerebral, pulmonary, cutaneous, digestive or disseminated infections, and their spread is favored by certain underlying diseases (diabetes, kidney failure) and risk factors (neutropenia, immunosuppression, iron overload). These infections have a high mortality rate, over 40% in many series, and the key to their cure depends on both an early diagnosis and an antifungal treatment, associated in most cases with extensive surgical debridement and other adjunctive therapies. Currently, there are international guidelines, not only local ones, for the management of mucormycosis, in which it is considered by consensus and with a strong recommendation that first-line treatment with high-dose liposomal amphotericin B is the best choice. The combined antifungal treatment of polyene agents with triazoles or candins remains in open debate.

Identification of Mucor circinelloides antigens recognized by sera from immunocompromised infected mice

BACKGROUND

Mucor circinelloides is an opportunistic fungus capable of causing mucormycosis, a highly aggressive infection of quick spreading. Besides, it also has a high mortality rate due to late diagnosis and difficult treatment.

AIMS

In this study we have identified the most immunoreactive proteins of the secretome and the total protein extract of M. circinelloides using sera from immunocompromised infected mice.

METHODS

The proteins of the secretome and the total extract were analyzed by two-dimensional electrophoresis and the most immunoreactive antigens were detected by Western Blot, facing the sera of immunocompromised infected mice to the proteins obtained in both extracts of M. circinelloides.

RESULTS

Seven antigens were detected in the secretome extract, and two in the total extract, all of them corresponding only to three proteins. The enzyme enolase was detected in both extracts, while triosephosphate isomerase was detected in the secretome, and heat shock protein HSS1 in the total extract.

CONCLUSIONS

In this work the most immunoreactive antigens of the secretome and the total extract of M. circinelloides were identified. The identified proteins are well known fungal antigens and, therefore, these findings can be useful for future research into alternatives for the diagnosis and treatment of mucormycosis.

Oral involvement in mucormycosis. A retrospective study of 55 cases

INTRODUCTION

Mucormycosis with oral involvement (OIM) is a rare opportunistic and lethal mycosis, which has increased in the last decade and is generally associated with uncontrolled diabetes and neutropenia.

METHODS

A retrospective study of cases with OIM was carried out in a tertiary-care center. Mycological and histological examinations were performed, and the isolated organisms were identified by morphology and molecular biology.

RESULTS

Fifty-five OIM patients were included, with a median age of 38 years (61.8% males). The most frequent associated disease was type-2 diabetes mellitus (61%), followed by neutropenia due to acute lymphocytic leukemia (27%). The main presentation was palatal and mandibular ulcers (92.7%) and, to a lesser extent, gingival and lingual necrosis. The diagnosis was established by mycological and histopathological studies. The most frequent fungi isolated was Rhizopus arrhizus (67.2%).

CONCLUSION

OIM is a rapidly progressing disease, therefore, an early diagnosis and the proper control of predisposing factors is necessary, and consequently, contributing to improve the outcome of mucormycosis.

Successful posaconazole salvage therapy for rhinocerebral mucormycosis in a child with leukemia. Review of the literature

BACKGROUND

Mucormycosis is a fungal infection caused by species of the Mucorales order. These microorganisms are angioinvasive, with rapid disease progression and potentially lethal in its rhinocerebral form.

CASE REPORT

We present the case of a 12-year-old female with trisomy 21, acute lymphoblastic leukemia and diabetes, with fever and neutropenia who developed rhinocerebral mucormicosis. After treatment with amphotericin B lipid complex and extensive surgery, disease progressed and posaconazole was added as salvage treatment with full remission of the infection. Four years after diagnosis the patient continues without relapse of mucormycosis or leukemia.

CONCLUSIONS

This case highlights the use of posaconazole as either monotherapy or combined therapy. Although it is still debated, it can be considered an option for salvage treatment in children with non-responding mucormycosis, despite lack of standard dosage in pediatric patients.

[Current therapeutic options in invasive mycosis and potential therapeutic role of isavuconazole]

The treatment of invasive fungal infections has deeply evolved in recent years with the inclusion of new antifungals to the therapeutic treatment arsenal. A new azole, isavuconazole, has been recently approved. This review focuses on the role of isavuconazole for treating the most important invasive fungal infections: invasive candidiasis, aspergillosis, mucormicosis, infections caused by other filamentous fungi and those caused by dimorphic fungi.

Characterization and phylogenetic analysis of a Cunninghamella bertholletiae isolate from a bottlenose dolphin (Tursiops truncatus)

BACKGROUND

Cunninghamella is a genus of the order Mucorales which includes saprophytic species, rarely causing mycoses. The most frequently reported in human mycoses is the thermophilic species Cunninghamella bertholletiae. However, this species does not appear to cause mucormycosis in animals, so there is scarce information about C. bertholletiae isolates from animals.

AIMS

In this paper we describe the phenotypic and genotypic characterization, and the phylogenetic analysis, of an isolate of C. bertholletiae involved in a central nervous system mucormycosis in a dolphin.

METHODS

The isolate studied in this publication was characterized using the current morphological and physiological identification system for Cunninghamella species. DNA sequencing and analysis of the D1/D2 regions of the 26S rRNA gene and the ITS-5.8S rRNA gene sequences were also performed.

RESULTS

Colonies were fast-growing, white at first, although they became tannish-gray, covering the whole plate after 7 days of incubation at 30 and 40°C. Limited growth was observed after 7 days at 45°C. The micromorphology showed characteristic erect sporangiophores. The identification of the isolate was confirmed by DNA sequencing of the D1/D2 regions of the 26S and the ITS-5.8S (ITS) rRNA gene sequencing.

CONCLUSIONS

In the phylogenetic study, the isolate clustered in the same clade as C. bertholletiae neotype strain although some differences were observed in the ITS sequences. In the cetacean cases, the possible sources of infection are unclear. The reasons why this pathogen has been found only in cetaceans and not in other domestic or wild animals are at the moment unknown and need further study.

Fungal necrotizing fasciitis, an emerging infectious disease caused by Apophysomyces (Mucorales)

BACKGROUND

The mucoralean fungi are emerging causative agents of primary cutaneous infections presenting in the form of necrotizing fasciitis.

AIMS

The aim of this study was to investigate a series of suspected necrotizing fasciitis cases by Apophysomyces species over one-year period in a northern Indian hospital.

METHODS

The clinical details of those patients suspected to suffer from fungal necrotizing fasciitis were recorded. Skin biopsies from local wounds were microscopically examined and fungal culturing was carried out on standard media. The histopathology was evaluated using conventional methods and special stains. Apophysomyces isolates were identified by their morphology and by molecular sequencing of the internal transcribed spacer (ITS) region of the ribosomal genes. Antifungal susceptibility testing was carried out following EUCAST guidelines and treatment progress was monitored.

RESULTS

Seven patients were found to be suffering from necrotizing fasciitis caused by Apophysomyces spp. Six isolates were identified as Apophysomyces variabilis and one as Apophysomyces elegans. Five patients had previously received intramuscular injections in the affected area. Three patients recovered, two died and the other two left treatment against medical advice and are presumed to have died due to their terminal illnesses. Posaconazole and terbinafine were found to be the most active compounds against A. variabilis, while the isolate of A. elegans was resistant to all antifungals tested.

CONCLUSIONS

Apophysomyces is confirmed as an aggressive fungus able to cause fatal infections. All clinicians, microbiologists and pathologists need to be aware of these emerging mycoses as well as of the risks involved in medical practices, which may provoke serious fungal infections such as those produced by Apophysomyces.

[Invasive fungal disease due to Scedosporium, Fusarium and mucorales]

The number of emerging organisms causing invasive fungal infections has increased in the last decades. These etiological agents include Scedosporium, Fusarium and mucorales. All of them can cause disseminated, virulent, and difficult-to treat infections in immunosuppressed patients, the most affected, due to their resistance to most available antifungal agents. Current trends in transplantation including the use of new immunosuppressive treatments, the common prescription of antifungal agents for prophylaxis, and new ecological niches could explain the emergence of these fungal pathogens. These pathogens can also affect immunocompetent individuals, especially after natural disasters (earthquakes, floods, tsunamis), combat wounds or near drowning. All the invasive infections caused by Scedosporium, Fusarium, and mucorales are potentially lethal and a favourable outcome is associated with rapid diagnosis by direct microscopic examination of the involved tissue, wide debridement of infected material, early use of antifungal agents including combination therapy, and an improvement in host defenses, especially neutropenia.

[Iron and invasive fungal infection]

Iron is an essential factor for both the growth and virulence of most of microorganisms. As a part of the innate (or nutritional) immune system, mammals have developed different mechanisms to store and transport this element in order to limit free iron bioavailability. To survive in this hostile environment, pathogenic fungi have specific uptake systems for host iron sources, one of the most important of which is based on the synthesis of siderophores-soluble, low-molecular-mass, high-affinity iron chelators. The increase in free iron that results from iron-overload conditions is a well-established risk factor for invasive fungal infection (IFI) such as mucormycosis or aspergillosis. Therefore, iron chelation may be an appealing therapeutic option for these infections. Nevertheless, deferoxamine -the first approved iron chelator- paradoxically increases the incidence of IFI, as it serves as a xeno-siderophore to Mucorales. On the contrary, the new oral iron chelators (deferiprone and deferasirox) have shown to exert a deleterious effect on fungal growth both in vitro and in animal models. The present review focuses on the role of iron metabolism in the pathogenesis of IFI and summarises the preclinical data, as well as the limited clinical experience so far, in the use of new iron chelators as treatment for mucormycosis and invasive aspergillosis.