Outbreak of intestinal infection due to Rhizopus microsporus

Disseminated Infections with Talaromyces marneffei in Non-AIDS Patients Given Monoclonal Antibodies against CD20 and Kinase Inhibitors

Infections with the fungus Talaromyces (formerly Penicillium) marneffei are rare in patients who do not have AIDS. We report disseminated T. marneffei infection in 4 hematology patients without AIDS who received targeted therapy with monoclonal antibodies against CD20 or kinase inhibitors during the past 2 years. Clinicians should be aware of this emerging complication, especially in patients from disease-endemic regions.

Healthcare-associated outbreaks due to Mucorales and other uncommon fungi

BACKGROUND

Healthcare-associated outbreaks of fungal infections, especially with uncommon and emerging fungi, have become more frequent in the past decade.

MATERIALS AND METHOD

Here, we reviewed the history and definition of healthcare-associated outbreaks of uncommon fungal infections and discussed the principles of investigating, containing and treatment of these outbreaks.

RESULTS

In case of these uncommon diseases, occurrence of two or more cases in a short period is considered as an outbreak. Contaminated medical devices and hospital environment are the major sources of these outbreaks. Care must be taken to differentiate a real infection from colonization or contamination. Defining and identifying cases, describing epidemiologic feature of cases, finding and controlling the source of the outbreak, treating patients, and managing asymptomatic exposed patients are main steps for outbreak elimination. These fungal outbreaks are not only difficult to detect but also hard to treat. Early initiation of appropriate antifungal therapy is strongly associated with improved outcomes in infected patients. Choice of antifungal drugs should be made based on spectrum, pharmacodynamic and pharmacokinetic characteristics and adverse effects of available drugs. Combination antifungal therapy and surgical intervention may be also helpful in selected cases.

CONCLUSIONS

A multidisciplinary approach and close collaboration between all key partners are necessary for successful control of fungal outbreaks.

Gastrointestinal mucormycosis requiring surgery in adults with hematologic malignant tumors: literature review

BACKGROUND

Gastrointestinal mucormycosis is associated with high mortality rates. Appropriate and early antifungal therapy and prompt surgical intervention are essential.

METHOD

Case report and literature review.

RESULTS

Nineteen case reports were reviewed describing adults with hematologic malignant tumors who developed intestinal mucormycosis and underwent surgery. The overall survival rate was 50%.

CONCLUSION

Intestinal mucormycosis is an infection associated with a high mortality rate although adults with underlying hematologic malignant have improved outcomes compared with other groups.

Fungi associated with drug recalls and rare disease outbreaks

Fungi rarely cause disease outbreaks associated with use of microbe-contaminated drugs. These rare episodes typically involve a restricted spectrum of common environmental species with relatively low virulence, rather than classical pathogens. Review of data involving over-the-counter contact lens solutions and prescription drug-related recalls revealed six episodes during the past decade with significant adverse health and financial impact (including loss of vision and death). Contaminations involved fungi mostly identified with the genera Aspergillus, Exserohilum, Fusarium, Paecilomyces, and Rhizopus. These organisms are noted for their capacity to produce resistant morphotypes (chlamydoconidia, ascospores) under various adverse conditions, generally with temperature survival/tolerances markedly in excess of maximal growth temperatures. High constituent levels of melanin, trehalose and heat-shock proteins facilitate differential survival of morphotypes following exposures to toxic chemicals and temperatures above 80 °C. Adverse environmental factors that induce resistant morphotypes are suggested to occur more readily in situ than during in vitro testing. Rare unexplained, sporadic drug contamination episodes with select thermotolerant fungi may relate, in part, to resistant dormant stages.

Clinical challenge: fatal mucormycotic osteomyelitis caused by Rhizopus microsporus despite aggressive multimodal treatment

BACKGROUND

Mucormycosis is an invasive mycotic disease caused by fungi in the zygomycetes class. Although ubiquitous in the environment, zygomycetes are rarely known to cause invasive disease in immunocompromised hosts with a high mortality even under aggressive antifungal and surgical therapy. Clinically, mucormycosis frequently affects the sinus occasionally showing pulmonary or cerebral involvement. However skeletal manifestation with Rhizopus microsporus (RM) osteomyelitis leading to emergency surgical proximal femoral resection with fatal outcome has not been described yet.

CASE PRESENTATION

We report the case of a 73-year-old male suffering from myelodysplastic syndrome with precedent bone marrow transplantation. Six months after transplantation he consulted our internal medicine department in a septic condition with a four week history of painful swelling of the right hip. Radiography, computed tomography and magnetic resonance imaging revealed multiple bone infarcts in both femurs. In the right femoral head, neck and trochanteric region a recent infarct showed massive secondary osteomyelitis, breaking through the medial cortex. Emergency surgical proximal femoral resection was performed due to extensive bone and soft tissue destruction. Microbiological and basic local alignment search tool (BLAST) analysis revealed RM. Amphotericin B and posaconazole treatment with septic revision surgery was performed. However the disease ran a rapid course and was fatal two months after hospital admission.

CONCLUSION

This alarming result with extensive RM osteomyelitis in the proximal femur of an immunocompromised patient may hopefully warn medical staff to perform early imaging and aggressive surgical supported multimodal treatment in similar cases.

Subcutaneous phaeohyphomycosis in a patient with IgG4-related sclerosing disease caused by a novel ascomycete, Hongkongmyces pedis gen. et sp. nov.: first report of human infection associated with the family Lindgomycetaceae

No members of the freshwater ascomycetes family Lindgomycetaceae have been associated with human infections. We isolated a mould (HKU35(T)) from the biopsy specimen of a patient with invasive foot infection and underlying immunoglobulin G4-related sclerosing disease. Histology showed florid, suppurative, granulomatous inflammation in the dermis, with central microabscess formation surrounded by epithelioid histiocytes, scattered giant cells, and a small number of lymphocytes. A Grocott stain revealed fungal elements in the center of the lesion. On Sabouraud glucose agar, HKU35(T) grew as gray and velvety colonies. Among the members of the family Lindgomycetaceae, HKU35(T) was the only strain that grew at 37°C. Microscopically, only sterile mycelia, but no fruiting bodies, were observed. HKU35(T) was susceptible to itrazonazole, voriconazole, and posaconazole, which was in line with the patient's clinical response to itraconazole treatment. Internal transcribed spacer and partial 18S nuclear rDNA (nrDNA), 28S nrDNA, β-tubulin gene, and EF1α gene sequencing showed that HKU35(T) occupied a unique phylogenetic position, most closely related to but distinct from members of the genera Clohesyomyces and Lindgomyces. We propose a new genus and species, Hongkongmyces pedis gen. et sp. nov., to describe this fungus, which belongs to the family Lindgomycetaceae in the orderPleosporales of class Dothideomycetes. This case also represents the first report of human infection associated with the family Lindgomycetaceae.

Fatal empyema thoracis caused by Schizophyllum commune with cross-reactive cryptococcal antigenemia

We report a fatal case of Schizophyllum commune empyema thoracis with cross-reactive cryptococcal antigenemia. In vitro testing confirmed the ability of the fungus to cause a positive cryptococcal antigen latex agglutination system (CALAS) test result. Such a result may lead to delay in diagnosis and treatment, as most strains of S. commune are resistant to fluconazole.

Clinical management and infection control of SARS: lessons learned

The outbreak of severe acute respiratory syndrome (SARS) in 2003 was the first emergence of an important human pathogen in the 21st century. Responding to the epidemic provided clinicians with extensive experience in diagnosing and treating a novel respiratory viral disease. In this article, we review the experience of the SARS epidemic, focusing on measures taken to identify and isolate patients, prevent the transmission of infection to healthcare workers and develop effective therapies. Lessons learned from the SARS epidemic will be especially important in responding to the current emergence of another highly pathogenic human coronavirus, the agent of Middle East respiratory syndrome (MERS), and to the recently emerging H7N9 influenza A virus in China. This paper forms part of a symposium in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses."

Management of an incident of failed sterilization of surgical instruments in a dental clinic in Hong Kong

BACKGROUND/PURPOSE

We describe an investigation of an incident of failed sterilization procedure in a dental clinic. We aim to illustrate the principles in performing such investigations and to highlight some of the important checkpoints in sterilization procedures.

METHODS

In response to this incident, proper sterilization of all equipment was performed immediately. On-site investigation was conducted by the investigation panel to identify the cause and risks, to coordinate post-exposure management in affected patients, and to make recommendations to prevent similar occurrence of such incidents in the future.

RESULTS

The incident was due to a rare lapse of monitoring during the autoclaving cycle. A total of 127 sources and 250 exposed patients were identified within 24 hours of the discovery of the incident for risk assessment and testing for blood-borne viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). A protocol was devised to manage the exposed patients against HBV, HCV, and HIV. Immunization and hyperimmune globulin for hepatitis B, and tetanus toxoids were given to the exposed patients where indicated. Exposed patients were followed-up for 6 months. We came to the decision that dating of instrument packages and signed documentation of each autoclave printout, color change of chemical indicators of each load and daily autoclave performance should be made mandatory with immediate effect.

CONCLUSION

Rapid response is extremely crucial in minimizing the impact of this incident and relieving the anxiety of the affected patients. Proper recording and documentation of autoclave cycles and regular auditing should be enforced to prevent similar incidents.

Epidemiology and treatment of mucormycosis

Mucormycosis is an uncommon but aggressive opportunistic fungal infection that afflicts patients with severe underlying immunosuppression, uncontrolled hyperglycemia and/or ketoacidosis, patients with iron overload resulting from frequent blood transfusions or blood disorders and occasionally healthy patients who are inoculated with fungal spores through traumatic injuries. The clinical presentation of mucormycosis is initially indistinguishable from other common infections, and if not diagnosed early and aggressively treated, it is almost always fatal. In this article we summarize recent changes in the epidemiology of mucormycosis, discuss diagnostic and clinical clues suggestive of the infection and provide a general strategy for managing the infection in the absence of data from well-controlled, prospective clinical trials.

Intestinal mucormycosis: a rare entity in pediatric oncology

Mucormycosis is increasingly emerging as an important cause of invasive fungal infection in immunocompromised patients. Intestinal mucormycosis is extremely rare, difficult to diagnose, and has dismal prognosis. We report two children with acute lymphoblastic leukemia and intestinal mucormycosis. Despite surgery and appropriate antifungal therapy, only one survived. Literature review showed only 10 other childhood cancer cases with intestinal mucormycosis. All had abdominal pain preceding gut perforation. All except one had leukemia and majority were in induction phase of therapy. Only 5 of these 12 children survived. Other than appropriate antifungal therapy, early surgery and rising neutrophils aid in recovery.

[Clinical and radiological aspects of mucormycosis]

Mucormycosis is an infection caused by filamentous fungi of the Mucorales order. The predisposing factors are mostly diabetic ketoacidosis and severe immunosuppressive conditions such as prolonged neutropenia, steroid or T-cell suppressor therapy, solid organ transplantation or allogeneic hematopoietic stem cell transplantation. Mucormycosis can also occur in immunocompetent patients, especially after trauma, burns or direct inoculation of the fungi (e.g. intravenous drug abuse). The most frequently targeted primary sites of infection are sinuses with a rapid spread to the adjacent tissues including the brain, the lower respiratory tract, the digestive tract and the skin. Mucorales are able to invade the vessels causing hematogenous dissemination, vascular thrombosis and, ultimately, necrosis of the lesions. Clinical and radiological aspects are similar to those observed in other invasive filamentous fungi infections such as invasive aspergillosis, fusariosis or scedosporiosis. CT-scan or MRI are mandatory to assess the extension of the lesions. The diagnosis remains difficult and is often delayed resulting in a poor outcome.

Sporopachydermia cereana fungaemia in refractory leukaemia presenting as breakthrough infection during micafungin therapy

The Sporopachydermia cereana species lives in decaying stems of cactus and is exceptionally rare as a human pathogen. A 57-year-old man with therapy-refractory acute promyelocytic leukaemia developed severe neutropaenia. After about 3 weeks of micafungin used as prophylaxis, he developed high fever, multiple pulmonary nodular infiltrates and a painful leg lesion. Blood culture yielded a yeast which was not identified by the Vitek 2 system. On ITS1-5.8S-ITS2 gene sequencing, the isolate was identified as S. cereana. Antifungal sensitivity by the Etest showed that the minimum inhibitory concentration for fluconazole was 0.75 μg/mL, and for anidulafungin, it was >32 μg/mL. He responded to liposomal amphotericin B but later died of Escherichia coli septicaemia. There were no cactus plants in the vicinity, suggesting that S. cereana might have alternative habitats.

Characterization of a Tsukamurella pseudo-outbreak by phenotypic tests, 16S rRNA sequencing, pulsed-field gel electrophoresis, and metabolic footprinting

We report a pseudo-outbreak of Tsukamurella due to improperly wrapped scissors used for processing of tissue specimens. A polyphasic approach, involving biochemical, genetic, and metabolomic techniques, was used in the laboratory investigation. This report highlights that early recognition of pseudo-outbreaks is important in preventing unnecessary and incorrect treatment of patients.

Phaeoacremonium parasiticum invasive infections and airway colonization characterized by agar block smear and ITS and β-tubulin gene sequencing

Phaeoacremonium parasiticum is an environmental dematiaceous mold rarely associated with human infections. We present here 2 cases of P. parasiticum invasive infections, including the first report of P. parasiticum respiratory tract infection, and 1 case of airway colonization, which all 3 strains of P. parasiticum were identified using agar block smear and ITS and β-tubulin gene sequencing. All 3 isolates grew initially as white to creamy, yeast-like colonies. After 21 days of incubation at 25 °C, 1 isolate remained light brown, atypical of P. parasiticum. Microscopic examination of agar block smear preparations of all 3 isolates showed thick-walled, medium brown conidiophores that were branched and slightly swollen at the base. The sequences of the ITS and β-tubulin genes of the 3 isolates were identical to those of P. parasiticum. Cases of P. parasiticum infections should be confirmed by a polyphasic approach using morphologic characterization and ITS and β-tubulin gene sequencing.

A significant number of reported Absidia corymbifera (Lichtheimia corymbifera) infections are caused by Lichtheimia ramosa (syn. Lichtheimia hongkongensis): an emerging cause of mucormycosis

Recently, we and others reported the discovery of Lichtheimia ramosa (syn. Lichtheimia hongkongensis). We also hypothesized that a proportion of ‘Absidia corymbifera (Lichtheimia corymbifera)' reported in the literature could be L. ramosa. In this study, we characterized 13 strains that had been reported as ‘A. corymbifera (L. corymbifera)' in the literature over an 11-year period. Microscopic examination of agar block smear preparations of all 13 strains showed abundant circinate side branches and pleomorphic giant cells with finger-like projections of L. ramosa. ITS1–5.8S–ITS2 rRNA gene cluster (internal transcribed spacer (ITS)) and partial elongation factor-1alpha (EF1α) gene sequencing showed that all 13 strains were clustered with L. ramosa; partial β-actin gene sequencing showed that most of the 13 strains were clustered with L. ramosa; and partial 28S rRNA gene sequencing showed that all 13 strains were clustered with L. ramosa, but one strain of L. corymbifera (HKU25) was also clustered with other strains of L. ramosa. A significant number of reported A. corymbifera (L. corymbifera) infections are L. ramosa infections which are of global distribution. In clinical microbiology laboratories, L. ramosa should be suspected if an Absidia-like mold that possesses abundant circinate side branches on the sporangiophores and pleomorphic giant cells with finger-like projections is observed. ITS and partial EF1α gene sequencing are more reliable than partial β-actin and 28S rRNA gene sequencing for identification of the Lichtheimia species.

Hospital-related outbreaks due to rare fungal pathogens: a review of the literature from 1990 to June 2011

Fungi can cause severe infections. Two or more nosocomial unusual fungal infections diagnosed in a short period should be assumed as an outbreak. The review's aim was to collect data to improve their management. The free online worldwide database for nosocomial outbreaks ( http://www.outbreak-database.com ) and the PubMed/MEDLINE database were used to collect the English literature published from 1990 to June 2011. The more common Candida spp. and Aspergillus spp. infections were excluded. For each outbreak, the following data were reviewed: species, duration, source and site of infection, ward, risk factors, number of patients infected, treatment, related mortality, type of epidemiological study and time elapsed between index cases and second cases. Thirty-six reports were considered: yeasts caused the majority of the outbreaks (16 out of 36). The median values for the overall duration, number of infected people per outbreak and infection-related mortality were 5 months, 4 and 20 %, respectively. Eighteen cases were caused by contaminated substances and 13 cases were hypothesised as human-transmitted. Nosocomial outbreaks due to rare fungal pathogens involve few patients but have high related mortality. These results could be explained by the diagnostic delay, the inability of recognising the source of the infections and the challenges of the treatment. More efforts should be concentrated to implement the application of proper hygiene practices to avoid human-human transmission.

Healthcare-associated mucormycosis

Mucormycosis is a severe emerging invasive fungal infection that occurs as a consequence of environmental exposure. We exhaustively reviewed all the cases of mucormycosis (European Organisation for Research and Treatment of Cancer/Mycoses Study Group 2008 criteria) attributed to healthcare procedures that occurred between 1970 and 2008. A total of 169 cases were studied (29% children, 61% male). Major underlying diseases were solid organ transplantation (24%), diabetes mellitus (22%), and severe prematurity (21%). Skin was the most common localization (57%), followed by gastrointestinal tract (15%). Culture results were available in 75% (92% positive), and results of histological examination were positive in 95%. Rhizopus was the most frequent genus (43%). Infection portal of entry included surgery and presence of medical devices such as catheters or adhesive tape. Outbreaks and clusters were related to adhesive bandages (19 cases), wooden tongue depressors (n = 5), ostomy bags (n = 2), water circuitry damage (n = 2), and adjacent building construction (n = 5). Thorough investigations are mandatory to identify healthcare-associated mucormycosis, notably in neonatology, hematological, and transplantation units.

Epidemiology and clinical manifestations of mucormycosis

Mucormycosis is an emerging angioinvasive infection caused by the ubiquitous filamentous fungi of the Mucorales order of the class of Zygomycetes. Mucormycosis has emerged as the third most common invasive mycosis in order of importance after candidiasis and aspergillosis in patients with hematological and allogeneic stem cell transplantation. Mucormycosis also remains a threat in patients with diabetes mellitus in the Western world. Furthermore, this disease is increasingly recognized in recently developed countries, such as India, mainly in patients with uncontrolled diabetes or trauma. Epidemiological data on this type of mycosis are scant. Therefore, our ability to determine the burden of disease is limited. Based on anatomic localization, mucormycosis can be classified as one of 6 forms: (1) rhinocerebral, (2) pulmonary, (3) cutaneous, (4) gastrointestinal, (5) disseminated, and (6) uncommon presentations. The underlying conditions can influence clinical presentation and outcome. This review describes the emerging epidemiology and the clinical manifestations of mucormycosis.

The emerging epidemiology of mould infections in developing countries

PURPOSE OF REVIEW

The present review describes the emerging trends of mould infections in developing countries, and highlights the major epidemiological differences from the developed countries.

RECENT FINDINGS

The limited data available from developing countries suggest an alarming increase in invasive mould infections, especially aspergillosis and mucormycosis, and also a difference in risk factors and causative agents between the developed and developing world. Sino-orbital, cerebral and ophthalmic infections due to Aspergillus flavus are the major clinical types in aspergillosis, after pulmonary aspergillosis. Aspergillus and Fusarium spp. are frequent causes of trauma-associated keratitis in agricultural workers. Rhino-orbito-cerebral presentation associated with uncontrolled diabetes is the predominant mucormycosis. Isolated renal mucormycosis has emerged as a new clinical entity. Apophysomyces elegans and Mucor irregularis are emerging species in these regions and uncommon agents such as Rhizopus homothallicus have also been reported. Many pathogens are geographically restricted, with Pythium insidionum, Rhinocladiella mackenziei and M. irregularis being described almost exclusively from Thailand, Middle East and China, respectively.

SUMMARY

Despite limited studies, certain peculiarities have been observed in invasive mould infections in developing countries, including a high incidence of ophthalmic lesions, mucormycosis and aspergillosis; few different clinical presentations; and a varied spectrum of pathogens involved in such lesions.

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.

Rapidly progressive cutaneous Rhizopus microsporus infection presenting as Fournier's gangrene in a patient with acute myelogenous leukemia

Members of the genus Rhizopus within the class Zygomycetes can cause devastating opportunistic infections. Cutaneous disease arising from direct inoculation of fungal spores has the potential to disseminate widely. Here, we describe a dramatic case of cutaneous Rhizopus infection involving the penis in a patient with acute myelogenous leukemia. Despite aggressive surgical debridement, systemic antifungal therapy, and donor lymphocyte infusion, the infection was ultimately fatal. This case illustrates the unique diagnostic and therapeutic challenges in the clinical management of cutaneous Rhizopus infection.

Survival of a patient with trauma-induced mucormycosis using an aggressive surgical and medical approach

BACKGROUND

Mucormycosis is a deadly angioinvasive fungal infection that is increasing in incidence. Gastrointestinal and abdominal involvement is rare, has higher mortality rates, and is frequently diagnosed late.

METHODS

We report a patient who sustained multiple gunshot wounds to the chest and abdomen and subsequently developed omental and hepatic mucormycosis. He underwent 14 abdominal washouts and several liver debridements, and he received combination therapy with amphotericin B and micafungin.

RESULTS

The patient survived the disease, with negative cultures and pathology at the last washout, and underwent skin grafting. He is clinically improved and remains on oral antifungals as an outpatient.

CONCLUSIONS

Mucormycosis should be considered in trauma patients with persistent signs of infection after lavage and antibiotics, especially when necrosis or atypical wound presentations are noted. Approaches such as ours using aggressive surgical management and intensive antifungal administration should be instituted once the diagnosis is suspected.

Nosocomial fungal infections: epidemiology, infection control, and prevention

Fungal infections are an increasing cause of morbidity and mortality in hospitalized patients. This article reviews the current epidemiology of nosocomial fungal infections in adult patients, with an emphasis on invasive candidiasis and aspergillosis. Recently published recommendations and guidelines for the control and prevention of these nosocomial fungal infections are summarized.

Intra-abdominal Rhizopus microsporus infection successfully treated by combined aggressive surgical, antifungal, and iron chelating therapy

Zygomycetes are widely distributed in the environment as inhabitants of soil and decaying matter. On rare occasions, these organisms can cause invasive infections in immunocompromised hosts. As zygomycetes are resistant to most conventional antifungal agents, its infection is often fatal. We report 2 cases of unusual intra-abdominal Rhizopus microsporus infection in children with acute leukemia as a result of an unprecedented outbreak due to oral intake of contaminated allopurinol tablets and ready-to-eat food items. Among the 2 patients, one of them survived after aggressive combined surgical, antifungal (AmBisome, Caspofungin, and Posaconazole) and iron chelation therapy.

Lichtheimia hongkongensis sp. nov., a novel Lichtheimia spp. associated with rhinocerebral, gastrointestinal, and cutaneous mucormycosis

Three thermotolerant "Absidia-like" isolates with unique morphologic characteristics, recovered from nasopharyngeal swab of a liver transplant recipient, gastric biopsy of a renal transplant recipient, and skin biopsy of a man with burn, respectively, were characterized. Microscopic examination showed nonseptate hyphae with highly branched sporangiophores. Uniquely, most side branches were circinate, and abundant pleomorphic giant cells with fingerlike projections were observed, characteristics absent from other Absidia/Lichtheimia spp. ITS1-5.8S-ITS2 rRNA gene cluster, partial EF1alpha gene, and partial beta-actin gene sequencing showed that the 3 strains formed a distinct cluster, most closely related to, but distinct from, Lichtheimia corymbifera, Lichtheimia blakesleeana, and Lichtheimia hyalospora. Based on the morphologic and genotypic characteristics, we propose a new species, Lichtheimia hongkongensis sp. nov., to describe this fungus, which caused rhinocerebral, gastrointestinal, and cutaneous mucormycosis, respectively, in 3 patients. A significant proportion of L. corymbifera associated with mucormycosis reported may be L. hongkongensis.

Ileocolonic mucormycosis in adult immunocompromised patients: A surgeon’s perspective

We report three cases of ileocolic mucormycosis in adult immunocompromised patients presenting as acute abdomen. All patients underwent laparotomy but two of them died from multiorgan failure before the diagnoses were confirmed. The diagnosis of gastrointestinal mucormycosis is rarely suspected, and antemortem diagnosis is made in only 25%-50% of cases. These cases illustrate the difficulty encountered by surgeons in managing acute abdomen in neutropenic patients with hematological malignancy. The management of colonic mucormycosis in the published literature is also reviewed.

Internal transcribed spacer region sequence heterogeneity in Rhizopus microsporus: implications for molecular diagnosis in clinical microbiology laboratories

Although internal transcribed spacer region (ITS) sequence heterogeneity has been reported in a few fungal species, it has very rarely been reported in pathogenic fungi and has never been described in Mucorales, causes of the highly fatal mucormycosis. In a recent outbreak investigation of intestinal mucormycosis due to Rhizopus microsporus infection in patients with hematological malignancies, PCR of the ITS of four of the 28 R. microsporus strains, P11, P12, D3-1, and D4-1, showed thick bands at about 700 bp. Direct sequencing of the purified bands showed frequent double peaks along all of the sequence traces and occasional triple peaks for P12, D3-1, and D4-1. The thick bands of the four R. microsporus strains were purified and cloned. Sequencing of 10 clones for each strain revealed two different ITS sequences for P11 and three different ITS sequences for P12, D3-1, and D4-1. Variations in ITS sequence among the different ribosomal DNA (rDNA) operons in the same strain were observed in only ITS1 and ITS2 and not the 5.8S rDNA region. One copy of P11, P12, and D4-1, respectively, and one copy of P11, P12, D3-1, and D4-1, respectively, showed identical sequences. This represents the first evidence of ITS sequence heterogeneity in Mucorales. ITS sequence heterogeneity is an obstacle to molecular identification and genotyping of fungi in clinical microbiology laboratories. When thick bands and double peaks are observed during PCR sequencing of a gene target, such a strain should be sent to reference laboratories proficient in molecular technologies for further identification and/or genotyping.