Mucormycete infection or colonisation: experience of an Australian tertiary referral centre

Targeted PCR of Mucorales in pediatric bronchoalveolar lavage samples indicates low prevalence of airway colonization and sample contamination

Mucorales are a large order of ubiquitous saprophytic zygomycete fungi and act as opportunistic pathogens in humans. In pediatric patients, little is known about the role of Mucorales in airway colonization and infection or their role as contaminants of respiratory samples. Currently, polymerase chain reaction (PCR) is the most sensitive mode of detection Mucorales in clinical specimen. In this study, we aimed to determine the prevalence of Mucorales in bronchoalveolar lavage samples (BAL) from a large, diverse group of pediatric patients. We performed commercial Mucorales PCR (MucorGenius®, Pathonostics, Maastricht, NL, USA) on 102 thawed BAL samples of 100 patients. Mucorales PCR was negative in all samples. Our data suggest that Mucorales spp. have a low prevalence in paediatric airways and do not frequently contaminate pediatric BAL samples.

Factors associated with cutaneous colonization of Mucormycetes in diabetic and non-diabetic individuals

This study was conducted to assess factors associated with cutaneous colonization of Mucormycetes in diabetic and non-diabetic individuals. A total of 800 swab samples from 200 participants including 100 diabetics and 100 non-diabetics were collected from four different body sites: (1) the forehead, (2) nasal cavity, (3) hands and (4) feet. Fungal isolation, fungal identification and antibiotic sensitivity tests were performed on the isolates. Overall, 12.0 % of the participants showed Mucormycetes colonization while the commonest fungal isolates were Mucor Species (Spp.). followed by Rhizopus spp. Diabetics had a 11 times higher odds of colonization compared to non-diabetics. The majority of the isolates were resistant to itraconazole; however, all isolates were sensitive to amphotericin B. A significant association was observed between profession and Mucormycetes (P=0.03) with significantly higher colonization in retired people compared to business people. Higher odds of colonization were demonstrated among older ages, lower class status and individuals with prolonged contact time with soil.

Rhinocerebral mucormycosis caused by Rhizopus oryzae in a patient with acute myeloid leukemia: A case report

BACKGROUND

Rhinocerebral mucormycosis (RCM) is a rare fatal fungal infection which is on the increase among immunocompromised hosts such as patients who have had hematological cancers, or have received immunosuppressive drugs, corticosteroids, or other T cell suppressing agents.

CASE SUMMARY

We report a case of RCM caused by Rhizopus oryzae, one of the most common opportunistic pathogens, in a patient suffering from a fourth relapse of acute myeloid leukemia. The patient developed RCM after he had received long-term antibiotic agents and corticosteroids. The pathogen was isolated three times from nasal secretions collected from the deep parts of the nasal cavity and was identified by morphology and internal transcribed spacer sequencing. Blood infection was excluded by droplet digital polymerase chain reaction and blood culture. The patient was empirically treated with caspofungin and voriconazole for several days while the lesions continued to progress. The patient was given amphotericin B in combination with caspofungin after RCM was suspected, and the lesions improved over the course of treatment, which lasted several days. However, the patient eventually died of the primary disease.

CONCLUSION

This case indicates that immunosuppressive drugs, including corticosteroids and antimetabolites in hematological tumor, do increase the risk of infections of this type. Early diagnosis, prompt and frequent surgical debridement, and treatment with amphotericin B without delay are all essential in combatting RCM.

Mucormycosis in lung transplant recipients: A systematic review of the literature and a case series

BACKGROUND

Mucormycosis is a rare infection in lung transplant recipients (LTR). Our objective was to better define the clinical presentation and optimal management of this frequently lethal infection.

METHODS

A systematic review of the literature was performed to identify all published cases of mucormycosis in LTR using PubMed/MEDLINE. These cases were analyzed together with a new case series from our clinic.

RESULTS

Literature search yielded 44 articles matching the inclusion criteria, describing 121 cases. Six additional cases were identified from our clinic. Data regarding infection site and outcome were available for a total of 53 patients. The lungs were the most common site of infection (62%), followed by rhinocerebral and disseminated disease. Most cases (78%) developed in the first post-transplant year, with over 40% of them in the first month. Additional risk factors for mucormycosis were identified in over half of the patients. Surgical debridement was uncommon in pulmonary infection (9%). Posaconazole therapy was used in 35% of cases, mostly in combination with amphotericin B. Overall mortality was 32% but varied according to site of infection.

CONCLUSION

Mucormycosis in LTRs tends to be an early post-surgical infection, associated with additional risk factors and intensified immunosuppressive states, and most often affects the lungs, where surgical debridement is rarely feasible. Posaconazole as first-line therapy should be further explored.

Fungal infection involvement in primary biliary cirrhosis: A review of 2 cases

The present study aimed to analyze the imaging, clinical and pathological features of fungal infection involvement in primary biliary cirrhosis (PBC) by retrospectively analyzing and reviewing the features of two patients with fungal infection involvement in PBC. Both patients were female. One patient had a confirmed diagnosis of PBC. The other patient had confirmed Sjogren syndrome and PBC. The two cases of PBC were infected with fungal infection after treatment with hormonal and immunosuppressive agents. RCR of sputum confirmed Pneumocystis spp. infection in the patient with PBC alone. The mucormycosis infection was confirmed in the other patient after pathological examination of a renal biopsy. The state of the illnesses progressed quickly and both patients ultimately succumbed to their conditions. The patient prognosis of fungal infection involvement PBC is poor. Patients treated with long-term hormone and immunosuppressive agents should be monitored.