Molecular epidemiology of zygomycosis and their related factors in tertiary referral centers in southern Iran

INTRODUCTION

For the best management of the zygomycosis in immunocompromised patients, the present study aims to detect and identify the etiologic agents by DNA sequencing method and their related factors in clinical samples of patients.

METHODOLOGY

Clinical samples from 1,058 patients admitted in 11 university hospitals in Shiraz, Southern Iran were collected between July 2015 and July 2018. All samples (bronchoalveolar lavage, sputum, blood, tissue) were examined by routine microscopic and culture tests for zygomycetes. The etiologic agents were identified by the molecular method and sequencing.

RESULTS

Direct microscopic examinations or pathology smear, culture, and PCR were positive in 61 (5.8%), 15 (1.4%), and 103 (9.7%) patients, respectively. According to EORTC/MSG criteria, the rates of proven, probable, and possible zygomycosis were 59.2% (61/103), 14.6% (15/103), and 26.2% (27/103 patients), respectively. The most prevalent etiologic agents according to sequencing were Rhizopus oryzae (44 cases), Rhizopus microsporus (31 cases), Rhizopus stolonifer (15 cases). Twenty-two patients (21.4%) with positive PCR died. There were significant relations between zygomycosis and the underlying disease (p = 0.043) and prior antifungal therapy (p = 0.023). White blood cell count was in the normal range in 14.1% of patients, and the means of erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) were 65 mm/hour and 57 mg/L, respectively.

CONCLUSIONS

Molecular methods and sequencing may have considered as suitable tools to diagnose zygomycosis. Identification of the etiologic agents may be considered as the future antifungal therapy and management of the respective patients.

Emerging mould infections: Get prepared to meet unexpected fungi in your patient

Invasive fungal diseases are increasing issues in modern medicine, where the human immunodeficiency virus (HIV) pandemic and the wider use of immunosuppressive drugs generate an ever-growing number of immunocompromised patients with an increased susceptibility to uncommon fungal pathogens. In the past decade, new species have been reported as being responsible for disseminated and invasive fungal diseases in humans. Among them, the following genera are rare but seem emerging issues: Scopulariopsis, Hormographiella, Emergomyces, Westerdykella, Trametes, Actinomucor, Saksenaea, Apophysomyces, and Rhytidhysteron. Delay in diagnosis, which is often the case in these infections, jeopardizes patients' prognosis and leads to increased mortality. Here we summarize the clinical and biological presentation and the key features to identify these emerging pathogens and we discuss the available antifungal classes to treat them. We focused on Pubmed to recover extensively reported human invasive cases and articles regarding the nine previously cited fungal organisms. Information concerning patient background, macroscopic and microscopic description and pictures of these fungal organisms, histological features in tissues, findings with commonly used antigen tests in practice, and hints on potential efficient antifungal classes were gathered. This review's purpose is to help clinical microbiologists and physicians to suspect, identify, diagnose, and treat newly encountered fungi in hospital settings.

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 infection masquerading as a brain tumor in an immunocompetent child

Saksenaea species are a rare cause of mucormycosis, the majority associated with cutaneous and subcutaneous infections resulting from trauma in both immunocompromised and immunocompetent individuals. Unlike other causative agents of mucormycosis, cerebral infections are exceptionally rare. We describe the first case of isolated cerebral infection by Saksenaea in a 4-year-old previously healthy male child who presented with headaches. He had no past medical history other than an episode of febrile seizures. In addition to raising the awareness of an unusual presentation of infection by Saksenaea, this case highlights the importance of pathologic examination for the prompt diagnosis of mucormycosis as well as the specific fungal identification for treatment as Saksenaea spp. may be more susceptible to posaconazole and less susceptible to amphotericin B compared to more common causes of mucormycosis.

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.

Necrotizing fungal infection due to Saksenaea erythrospora: A case report and review of literature

Mucormycosis caused by Saksenaea erythrospora is an emerging infection seen with soil contamination, burns and/or nosocomial infections. PCR amplification and internal transcribed spacer sequencing is gold standard for its identification. Here, we report a case of necrotizing fungal orbital infection by S. erythrospora in an immunocompetent child.

Mucormycosis: Battle with the Deadly Enemy over a Five-Year Period in India

Mucormycosis is an emerging opportunistic fungal infection. Increasing immunocompromization, widespread use of antibacterial and antifungal agents (such as voriconazole prophylaxis), carcinomas, transplantation and lifestyle diseases such as diabetes are the main contributors to this situation. The predominant clinical manifestations of mucormycosis vary from host to host, with rhino-orbital-cerebral, pulmonary, cutaneous, and gastrointestinal infections being the most common. In India, the prevalence of mucormycosis is approximately 0.14 cases/1000 population, which is about 70 times the worldwide-estimated rate for mucormycosis. The present study was undertaken over a period of five years (January 2009-December 2014) to determine the prevalence of mucormycosis. The samples suspected of mucormycosis were examined by direct KOH wet mount and cultured on Sabouraud's dextrose agar without actidione and on blood agar as per standard mycological techniques. Histopathological correlation was done for most of the cases. Antifungal susceptibility testing was performed by the EUCAST reference method. We identified a total of 82 cases of mucormycosis out of a total of 6365 samples received for mycological culture and examination during the said time period. Out of these, 56 were male patients and 27 were females. Most common presentation was rhino-orbito-cerebral (37), followed by cutaneous (25), pulmonary (14), oral cavity involvement (4) and gastrointestinal (2). The most common risk factors were diabetes and intramuscular injections. The fungi isolated were Rhizopus arrhizus (17), Apophysomyces variabilis (12), R. microsporus (9), Lichtheimia ramosa (8), Saksenaea erythrospora (5), Syncephalastrum racemosus (4), R. homothallicus (2), Rhizomucor pusillus (1), Mucor irregularis (1) and A. elegans (1). The mainstay of the treatment was amphotericin B, along with extensive surgical debridement whenever feasible. Most of the patients (50) recovered, but 25 died. The rest of the patients left against medical advice. "Nip in the Bud" should be the mantra for clinicians/surgeons for a favorable prognosis. Early diagnosis, prompt institution of appropriate antifungal therapy, surgical debridement whenever necessary, knowledge of risk factors and their timely reversal is the key for management.

Chronic orbital and calvarial fungal infection with Apophysomyces variabilis in an immunocompetent patient

Apophysomyces is a rare fungal organism causing rhino-orbito-cerebral mycotic infections with high morbidity and mortality, typically in immunocompetent individuals. Several cases of Apophysomyces elegans orbital disease have been reported. Herein, we report a case of Apophysomyces variabilis infection involving the orbit, sinuses, and calvarium in an immunocompetent 74-year-old woman, with a review of the literature. Unlike prior cases of A. elegans classic rhino-orbito-cerebral infection, our case included diffuse calvarial lytic lesions and overlying soft tissue nodules, but without parenchymal intracranial involvement. There was radiographic and clinical evidence of infarction of the orbital contents and cavernous sinus thrombosis. Anastomoses between the superior orbital (ophthalmic) vein and diploic veins of the calvarium are believed to be primarily responsible for the unusual mode of spread on the extradural surface of the brain. Although the patient stabilized without definitive surgical intervention, her disease slowly and intermittently progressed for over a year after presentation, requiring multiple courses of antifungal treatment.

Saksenaea erythrospora infection after medical tourism for esthetic breast augmentation surgery

BACKGROUND

Mucormycosis caused by Saksenaea erythrospora is rarely reported in humans. Three previous cases have been reported in the literature, two associated with trauma (a sailing accident in Argentina and a combat trauma in Iraq) and one as a cause of invasive rhinosinusitis (India), all in immunocompetent patients . The first case of mucormycosis following esthetic surgery, associated with medical tourism, is reported herein.

CASE REPORT

A case study of an S. erythrospora infection in an immunocompetent woman after the completion of esthetic surgery (dermolipectomy and breast augmentation) is reported. The infection presented as a rapidly progressive necrotizing infection of the skin and soft tissue, which required a bilateral mastectomy and extensive surgical debridement associated with prolonged antifungal therapy. The organism was identified phenotypically and confirmed biologically after rDNA amplification and sequencing. Two months later, the patient remains hospitalized awaiting the start of reconstructive surgeries. The present case is, to the best of the authors' knowledge, the first report from Colombia.

CONCLUSIONS

Mucormycosis should be considered in the differential diagnosis of necrotizing infections of the skin and soft tissue that evolve rapidly after cosmetic surgery performed in tropical or subtropical countries.

Mucormycosis in Australia: contemporary epidemiology and outcomes

Mucormycosis is the second most common cause of invasive mould infection and causes disease in diverse hosts, including those who are immuno-competent. We conducted a multicentre retrospective study of proven and probable cases of mucormycosis diagnosed between 2004-2012 to determine the epidemiology and outcome determinants in Australia. Seventy-four cases were identified (63 proven, 11 probable). The majority (54.1%) were caused by Rhizopus spp. Patients who sustained trauma were more likely to have non-Rhizopus infections relative to patients without trauma (OR 9.0, p 0.001, 95% CI 2.1-42.8). Haematological malignancy (48.6%), chemotherapy (42.9%), corticosteroids (52.7%), diabetes mellitus (27%) and trauma (22.9%) were the most common co-morbidities or risk factors. Rheumatological/autoimmune disorders occurred in nine (12.1%) instances. Eight (10.8%) cases had no underlying co-morbidity and were more likely to have associated trauma (7/8; 87.5% versus 10/66; 15.2%; p <0.001). Disseminated infection was common (39.2%). Apophysomyces spp. and Saksenaea spp. caused infection in immuno-competent hosts, most frequently associated with trauma and affected sites other than lung and sinuses. The 180-day mortality was 56.7%. The strongest predictors of mortality were rheumatological/autoimmune disorder (OR = 24.0, p 0.038 95% CI 1.2-481.4), haematological malignancy (OR = 7.7, p 0.001, 95% CI 2.3-25.2) and admission to intensive care unit (OR = 4.2, p 0.02, 95% CI 1.3-13.8). Most deaths occurred within one month. Thereafter we observed divergence in survival between the haematological and non-haematological populations (p 0.006). The mortality of mucormycosis remains particularly high in the immuno-compromised host. Underlying rheumatological/autoimmune disorders are a previously under-appreciated risk for infection and poor outcome.