Saksenaea vasiformis infections: case report and literature review

Diverse Clinical Manifestations and Challenges of Mucormycosis: Insights From Serial Cases

Mucormycosis is a severe and potentially life-threatening infection caused by a group of fungi classified as mucormycetes within the scientific order Mucorales. These infections are characterized by rapid and invasive fungal growth, presenting significant treatment challenges. Here we present 5 cases encountered from 2018 to 2022 at the University of Texas Medical Branch in Galveston, Texas, including a novel Apophysomyces species. These cases illustrate the diverse clinical manifestations of mucormycosis, including pulmonary, rhino-cerebral, gastrointestinal, and soft tissue involvement. Our investigation incorporates information provided by a multidisciplinary team of clinical collaborators, emphasizing the findings from radiology, histopathology, and microbiology. Given the escalating global incidence of mucormycosis, it is crucial for clinicians to become familiar with associated clinical findings, comorbidities, and risk factors to facilitate prompt recognition, appropriate diagnostic testing, and timely initiation of treatment.

Mucormycosis following burn injuries: A systematic review

INTRODUCTION

Mucormycosis is an opportunistic fungal infection with a high mortality rate. Though typically associated with diabetes and other conditions that affect innate immune function, infections can also be precipitated by conditions such as trauma and burns. Burn patients are particularly susceptible to fungal infections due to the immune dysfunction that often accompany their wounds. Indeed case series have described mucormycosis to occur in patients with burn injuries, however the factors contributing to mortality have not been well described. Thus, the purpose of our review was to identify factors contributing to morbidity and mortality in burn patients with Mucormycosis.

METHODS

A systematic review of the literature of mucormycosis infection in burn injury patients was performed on Pubmed and Google Scholar using the keywords: Mucor, Mucorales, Mucormycosis, Mucormycotina, Zygomycosis and burn or thermal injury. Clinical trials, observational studies, case reports, and case reviews were included if they provided information regarding mortality in adult and pediatric burn patients diagnosed with mucormycosis, review articles, non-English articles, and articles without patient information were excluded. No time limit was placed on our review. Individual patient data was stratified based on mortality. Statistical analysis was performed to investigate the relationship between patient risk factors and mortality, and the Oxford Level of Evidence was used to evaluate study quality.

RESULTS

46 articles were included in our final review, encompassing 114 patients. On average, survivors had a total body surface area (TBSA)% of 46 (SD 19.8) while non-survivors had a TBSA of 65% (SD 16.4), and this difference was significant (p < .001). Patients with disseminated mucormycosis experienced an 80% mortality rate compared to 36% mortality rate in patients with localized disease (p < .001). We found no statistically significant difference in mean age (p > .05), diabetes (p > .05), mean delay in diagnosis (p > .05), time to antifungal therapy (p > .05), or type of therapy used (p > .05) between survivors and non-survivors. Our review was limited by the lack of prospective, controlled trials; thus, our review primarily consists of case reports.

CONCLUSION

Disseminated infections and higher TBSA both increased the risk of mortality in burn patients with mucormycosis, while diabetes did not increase mortality risk. The severity of the initial injury and infection locations must be taken into consideration to inform patient prognosis.

Mucormycosis in burns: a review

Mucormycosis is a rare fungal infection with a high mortality rate. It presents with scattered black/necrotic ulcers, white fungal elements, and progression of wounds despite seemingly adequate debridement. Diagnosis is confirmed on wound histology, however this is often delayed. There is currently no comprehensive review of burn related mucormycosis within the literature, making this the first paper to provide evidence-based treatment guidance. We performed a review of publications from 1946 - present. There were 151 cases of mucormycosis complicating burns. The mortality rate was 54.5%, and there was a significant increase in mortality with axial body site involvement compared with isolated peripheral involvement. The standard treatment was prompt and radical debridement. Utilisation of frozen section to guide debridement aided in clinical decision making. No systemic treatment reached statistical significance, however amphotericin B trended towards significance. Although there is no strong evidence for topical amphotericin B or hyperbaric oxygen, there may be benefit in some cases. This study recommends early radical debridement in conjunction with the European Confederation of Medical Mycology guidelines of IV liposomal/lipid complex amphotericin B >5mg/kg/day, with posaconazole 800mg daily in divided doses as a salvage or oral step-down 1.

High-Temperature-Tolerant Fungus and Oomycetes in Korea, Including Saksenaea longicolla sp. nov

Global temperatures are steadily increasing, leading to significant changes in microbial diversity and ecology. In the present study, we isolated high-temperature-growing fungi and fungi-like group (Oomycota) strains from freshwater environments of Korea and identified them based on cultural, morphological, and multilocus phylogenetic analyses. As a result, we introduce Saksenaea (Fungi) isolates as a new species, Saksenaea longicolla sp. nov. and record Phytophthora chlamydospora and P. lagoariana (Oomycota) new to Korea. In the growth experiments, they exhibited high-temperature tolerance, which can grow at 35-40 °C but become inactive at 4 °C and below. This study confirms the presence of high-temperature-tolerant fungi and oomycetes in Korea and suggests that the Korean climate conditions are changing in favor of these species. This indicates that climate warming is altering microbial distributions in freshwater environments.

Factors Associated with Mortality Following Burns Complicated by Necrotizing Skin and Soft Tissue Infections: A Systematic Review and Meta-analysis of Individual Participant Data

We reviewed studies with individual participant data of patients who sustained burn injury and subsequently developed necrotizing skin and soft tissue infections (NSTI). Characteristics and managements were compared between patients who lived and patients who died to determine factors associated with mortality. Six databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus and CINAHL) were searched. PRISMA-IPD guidelines were followed throughout the review. Eligible patients sustained a burn injury, treated in any setting, and diagnosed with a NSTI following burn injury. Comparisons were made between burned patients who lived "non-mortality" and burned patients who died "mortality" following NSTI using non-parametric univariate analyses. Fifty-eight studies with 78 patients were published from 1970 through 2019. Non-mortality resulted in 58 patients and mortality resulted in 20 patients. Patients with mortality had significantly greater median %TBSA burned (45%[IQR:44-64%] versus 35%[IQR:11-59%],p=0.033), more intubations (79% versus 43%,p=0.013), less debridements (83% versus 98%,p=0.039), less skin excisions (83% versus 98%,p=0.039), more complications (100% versus 50%,p<0.001), management at a burn center (100% versus 71%,p=0.008), underwent less flap surgeries (5% versus 35%,p=0.014), less graft survival (25% versus 86%,p<0.001), and less healed wounds (5% versus 95%,p<0.001), compared to patients with non-mortality, respectively. Non-mortality patients had more debridements, skin excised, systemic antimicrobials, skin graft survival, flaps, improvement following surgery and healed wounds compared to mortality patients. Mortality patients had greater %TBSA burned, intubations, management at a burn center and complications compared to non-mortality patients.

Orbital Infection by Saksenaea vasiformis in an Immunocompetent Host

Orbital mucormycosis caused by Saksenaea vasiformis is extremely rare. Herein, we report an immunocompetent 22-year-old Thai female who presented with two months of progressive right upper eyelid mass, associated with swelling, redness, and ptosis. She failed to improve despite multiple courses of antibiotic and steroid treatment. Computed tomography (CT) scan showed infiltration involving the upper eyelid and lacrimal gland. Fungal hyphae were revealed by histopathological study. Polymerase chain reaction (PCR) was positive for Saksenaea vasiformis (GenBank: accession number FR687327.1). The patient was successfully treated with surgical debridement, amphotericin B, and oral posaconazole.

A case of mistaken identity: Saksenaea vasiformis of the orbit

The authors describe a rare presentation of invasive fungal rhino-orbital cellulitis caused by Saksenaea vasiformis in an immunocompetent child. The patient was initially diagnosed and treated as Mucoraceae, which has a high mortality rate and is primarily seen in immunocompromised patients. Though of the same order, Mucorales, the families Mucoraceae and Saksenaeacae, may be difficult to differentiate on histologic examination and must be distinguished by fungal culture and speciation. Our patient responded well to sino-orbital debridement and systemic treatment with amphotericin and posaconazole.

Saksenaea dorisiae sp. nov., a New Opportunistic Pathogenic Fungus from Europe

A new species, Saksenaea dorisiae (Mucoromycotina, Mucorales), isolated from a water sample originating from a private well in Manastirica, Petrovac, in the Republic of Serbia (Europe), is described and illustrated. The new taxon is well supported by multilocus phylogenetic analysis that included the internal transcribed spacer (ITS) region, domains D1 and D2 of the 28S rRNA gene (LSU), and translation elongation factor-1α gene (tef-1α), and it is resolved in a clade with S. oblongispora and S. trapezispora. This fungus is characterized by its moderately slow growth at 15 and 37°C, sparse rhizoids, conical-shaped sporangia, and short-cylindrical sporangiospores. Saksenaea dorisiae is a member of the opportunistic pathogenic genus often involved in severe human and animal mucormycoses encountered in tropical and subtropical regions. Despite its sensitivity to several conventional antifungals (terbinafine and ciclopirox), the fungus can potentially evoke clinically challenging infections. This is the first novel taxon of the genus Saksenaea described from the moderately continental climate area of Europe.

Saksenaea vasiformis infections: A case of an immunocompetent adult after mild injury and a literature review

Saksenaea vasiformis is an emerging human pathogen, belonging to the order Mucorales of the subphylum Mucormycotina, most often associated with rhino-cerebral, cutaneous and subcutaneous infections following trauma. A review of the published literature was attempted on the occasion of a cutaneous leg infection with favorable outcome in a young immunocompetent man after mild injury. The overall aim was the facilitation of the study and the integrated understanding of this kind of fungal infections.

Infection Due to Saksenaea vasiformis Following a Spider Bite

Cutaneous mucormycosis due to Saksenaea vasiformis species is exceptional. There have been about 40 reported cases worldwide, with most being fatal. We report an exceptional nonlethal case of mucormycosis due to S. vasiformis following a spider bite. The patient was in an immunosuppressed state owing to previous chemotherapy and diabetes mellitus. The origin of the inoculation was the bite of a Loxosceles laeta spider, which caused loxoscelism. The initial skin injury was quickly progressive, requiring amputation of the right upper limb. After surgical intervention and suitable antifungal treatment, the patient was discharged with resolution of accompanying pulmonary disease. Infections due to S. vasiformis are probably underdiagnosed. To avoid fatal outcomes, a high index of clinical suspicion in patients with quickly progressive necrotic lesions of soft tissues and systemic dissemination is important.

Mucormycosis in Burn Patients

Patients with extensive burns are an important group at risk for cutaneous mucormycosis. This study aimed to perform a systematic review of all reported mucormycosis cases in burn patients from 1990 onward. A Medline search yielded identification of 7 case series, 3 outbreaks, and 25 individual cases reports. The prevalence reached 0.04%–0.6%. The median age was 42–48 in the case series and outbreaks, except for the studies from military centers (23.5–32.5) and in individual reports (29.5). The median total body surface area reached 42.5%–65%. Various skin lesions were described, none being pathognomonic: the diagnosis was mainly reached because of extensive necrotic lesions sometimes associated with sepsis. Most patients were treated with systemic amphotericin B or liposomal amphotericin B, and all underwent debridement and/or amputation. Mortality reached 33%–100% in the case series, 29%–62% during outbreaks, and 40% in individual cases. Most patients were diagnosed using histopathology and/or culture. Mucorales qPCR showed detection of circulating DNA 2–24 days before the standard diagnosis. Species included the main clinically relevant mucorales (i.e., Mucor, Rhizopus, Absidia/Lichtheimia, Rhizomucor) but also more uncommon mucorales such as Saksenaea or Apophysomyces. Contact with soil was reported in most individual cases. Bandages were identified as the source of contamination in two nosocomial outbreaks.

Successful Treatment of Saksenaea sp. Osteomyelitis by Conservative Surgery and Intradiaphyseal Incorporation of Amphotericin B Cement Beads

Osteoarticular mucormycosis cases are quite rare and challenging infections that are mostly due to direct inoculation during traumatic injury among immunocompetent patients. Classic management includes a combination of aggressive surgical debridement, which may lead to amputation, and long-term systemic liposomal amphotericin B therapy. This article describes the successful treatment of Saksenaea sp. osteomyelitis in a patient with diabetes mellitus, using a combination of systemic antifungal therapy and conservative surgery with insertion of amphotericin-impregnated cement beads.

Saksenaea vasiformis Orbital Cellulitis in an Immunocompetent Child Treated With Posaconazole

An 11-year-old immunocompetent girl presented with two and a half months of progressive right orbital cellulitis, which did not respond to multiple courses of antibiotics or prednisone. A panfungal polymerase chain reaction primer was positive for Saksenaea vasiformis, and she completed 5 months of oral posaconazole therapy after debridement. Saksenaea vasiformis is a rare cause of zygomycosis, and it typically causes skin and soft tissue infection in immunocompetent hosts, particularly after a traumatic injury. The diagnosis should be considered in cases with a protracted course that fail to respond to typical antibiotic therapy. Treatment includes surgical debridement, in additional to antifungal therapy with amphotericin B or posaconazole.

A longitudinal study of serological responses to Coxiella burnetii and shedding at kidding among intensively-managed goats supports early use of vaccines

Vaccination against Coxiella burnetii, the cause of Q fever, is reportedly the only feasible strategy of eradicating infection in ruminant herds. Preventive vaccination of seronegative goats is more effective in reducing shedding of C. burnetii than vaccinating seropositive goats. The age at which goats born on heavily-contaminated farms first seroconvert to C. burnetii has not yet been documented. In a 16-month birth cohort study, the age at which goats seroconverted against C. burnetii was investigated; 95 goats were bled every 2 weeks and tested for antibodies against C. burnetii. Risk factors for seroconversion were explored and goats shedding C. burnetii were identified by testing vaginal swabs taken at the goats' first kidding using a com1 polymerase chain reaction assay. The first surge in the number of goats with IgM to C. burnetii was observed at week 9. Thus, a first vaccination not later than 8 weeks of age to control C. burnetii in highly contaminated environments is indicated. The odds of seroconversion were 2.0 times higher [95% confidence interval (CI) 1.2, 3.5] in kids born by does with serological evidence of recent infection (IgM seropositive) compared to kids born by IgM seronegative does, suggesting either in utero transmission or peri-parturient infection. The rate of seroconversion was 4.5 times higher (95% CI 2.1, 9.8) during than outside the kidding season, highlighting the risk posed by C. burnetii shed during kidding, even to goats outside the kidding herd. Shedding of C. burnetii at kidding was detected in 15 out of 41 goats infected before breeding.

Saksenaea vasiformis infection in an immunocompetent patient in rural Australia

An 81-year-old man from rural Australia presented with right pretibial cellulitis 7 days after minor trauma against furniture. He failed to improve despite antibiotics and surgical debridement. Subsequent cultures grew the rare fungus Saksenaea vasiformis, which was treated with further surgical debridement, amphotericin B and posaconazole. This was successful and the patient made a full recovery. We present the case and discuss lessons learnt.

Saksenaea erythrospora infection following a serious sailing accident

Saksenaea erythrospora is a species of the order Mucorales recently described and reported as a cause of human mucormycosis. We report a case of S. erythrospora in a man involved in a serious sailing accident causing deep skin and soft tissue contamination with soil and water. Direct microscopic examination of the clinical sample with Giemsa stains showed hyaline and non-septate hyphae belonging to the order Mucorales. Fungal identification was performed by culture of biopsy material on SDA, and identification of species by floating an agar block containing the fungus in a nutritionally deficient medium consisting of sterile distilled water supplemented with 0.05 % yeast extract; and by sequencing the ITS region of the rDNA. This is the first report to our knowledge of infection with S. erythrospora in Argentina, confirming the presence of this fungus in this country.

Disseminated infection due to Saksenaea vasiformis secondary to cutaneous mucormycosis

Mucormycosis is an uncommon opportunistic fungal infection caused by Zygomycetes. It usually affects immunocompromised, diabetic and trauma patients with infected wounds. We report a case of disseminated infection secondary to facial cutaneous mucormycosis caused by Saksenaea vasiformis in a diabetic patient who had a farming accident causing him severe head injury. The patient was treated with a combination of surgical debridement and antifungal therapy with liposomal amphotericin B, but he had a slow and fatal outcome. In cases of tissue necrosis following trauma involving wound contact with soil (i.e., potential fungal contamination), testing for the presence of Zygomycetes fungi such as S. vasiformis in both immunocompetent and immunocompromised patients is crucial. The reason is that this infection usually has a rapid progression and may be fatal if appropriate treatment is not administered.

[Necrotising fasciitis caused by Saksenaea vasiformis in an immunocompetent patient after a car accident]

BACKGROUND

Cutaneous mucormycosis (zygomycosis), with subcutaneous spreading and dissemination, in immunocompetent patients is an uncommon disease caused by species belonging to the fungal genera Apophysomyces, Rhizopus and Saksenaea, among others.

CASE REPORT

A case of necrotising fasciitis by Saksenaea vasiformis in an immunocompetent woman is described. The infection was acquired through a car accident resulting in multiple injuries affecting mainly her right arm. After the surgical reduction of fractures, skin lesions worsened and led to necrosis. The patient quickly developed a severe necrotising fasciitis with negative cultures at first. Despite the extensive surgical debridement and the aggressive antifungal treatment, the patient died. The histopathological study showed a fungal infection due to a fungus belonging to the Mucorales order, which was confirmed by culturing the clinical sample on Sabouraud agar, and identifying the species by cultures on Czapek-Dox agar, and sequencing of the ITS region of the ribosomal DNA.

CONCLUSIONS

This case confirm the presence of this fungus in Spain, the value of histopathology for the mucormycosis diagnosis, as well as the need to perform special cultures to facilitate their isolation and identification to the species level by the combined use of Czapek-Dox agar and sequencing of the ITS region.

Fatal primary cutaneous zygomycosis caused by Saksenaea vasiformis: case report and review of literature

BACKGROUND

Primary cutaneous zygomycosis caused by Saksenaea vasiformis is rare. Such infections usually are not suspected, and delay in their diagnosis and treatment results in a poor outcome.

METHODS

Case report and review of the relevant English-language literature.

RESULTS

A fulminant cutaneous infection developing after intramuscular injection in the gluteal region of a 60-year-old female patient is described. The hallmark of this uncommon infection was the rapidity with which the skin and subcutaneous tissues of the right gluteal and lower abdominal regions underwent necrosis. The infection remained undiagnosed for nearly two weeks, leading to a fatal outcome.

CONCLUSION

Awareness of the fact that fungi can also be the cause of cutaneous infections, as well as a high index of suspicion in patients who do not respond to conventional therapy, should help in the early diagnosis and management of such infections and may help in reducing the mortality rate.

Saksenaea erythrospora infection following combat trauma

Saksenaea erythrospora is a newly described species of the order Mucorales which has not previously been reported as a cause of human infection. We report a fatal case of S. erythrospora invasive burn wound infection in a 26-year-old male injured during combat operations in Iraq.

Mucormycosis caused by unusual mucormycetes, non-Rhizopus, -Mucor, and -Lichtheimia species

Rhizopus, Mucor, and Lichtheimia (formerly Absidia) species are the most common members of the order Mucorales that cause mucormycosis, accounting for 70 to 80% of all cases. In contrast, Cunninghamella, Apophysomyces, Saksenaea, Rhizomucor, Cokeromyces, Actinomucor, and Syncephalastrum species individually are responsible for fewer than 1 to 5% of reported cases of mucormycosis. In this review, we provide an overview of the epidemiology, clinical manifestations, diagnosis of, treatment of, and prognosis for unusual Mucormycetes infections (non-Rhizopus, -Mucor, and -Lichtheimia species). The infections caused by these less frequent members of the order Mucorales frequently differ in their epidemiology, geographic distribution, and disease manifestations. Cunninghamella bertholletiae and Rhizomucor pusillus affect primarily immunocompromised hosts, mostly resulting from spore inhalation, causing pulmonary and disseminated infections with high mortality rates. R. pusillus infections are nosocomial or health care related in a large proportion of cases. While Apophysomyces elegans and Saksenaea vasiformis are occasionally responsible for infections in immunocompromised individuals, most cases are encountered in immunocompetent individuals as a result of trauma, leading to soft tissue infections with relatively low mortality rates. Increased knowledge of the epidemiology and clinical presentations of these unusual Mucormycetes infections may improve early diagnosis and treatment.

Molecular phylogeny and proposal of two new species of the emerging pathogenic fungus Saksenaea

Saksenaea is a monotypic genus belonging to the order Mucorales and capable of producing severe human infections. Through a polyphasic study based on analysis of the sequences of the internal transcribed spacer (ITS) region, domains D1 and D2 of the 28S rRNA gene, and the elongation factor 1α (EF-1α) gene, as well as by evaluation of relevant morphological and physiological characteristics of a set of clinical and environmental strains, we have demonstrated that Saksenaea vasiformis is a complex of species. We propose as new species Saksenaea oblongispora, characterized by oblong sporangiospores and unable to grow at 42°C, and Saksenaea erythrospora, characterized by large sporangiophores and sporangia and by ellipsoid sporangiospores, biconcave in the lateral view. Itraconazole, posaconazole, and terbinafine were active against all isolates included in the study, while amphotericin B, voriconazole, and the echinocandins showed low activity.

Fatal Actinomucor elegans var. kuwaitiensis infection following combat trauma

We report the first case of invasive mucormycosis secondary to Actinomucor elegans infection. A severely injured soldier with a fatal A. elegans var. kuwaitiensis infection is described. The identification of this fungus was performed by classical and molecular methods, and this report documents the pathogenicity of the recently described variety Actinomucor elegans var. kuwaitiensis.

Molecular diagnosis of Saksenaea vasiformis cutaneous infection after scorpion sting in an immunocompetent adolescent

We report the first case of cutaneous mucormycosis after a scorpion sting in Tunisia. Histopathology showed broad aseptate hyphae suggestive of a Zygomycete. Saksenaea vasiformis was identified by PCR amplification and sequencing of the fungal DNA on a cutaneous biopsy. Successful treatment was obtained by surgery and liposomal amphotericin B.