Actinomycetoma of the scalp after a car accident

Updated Review on Nocardia Species: 2006-2021

This review serves as an update to the previous Nocardia review by Brown-Elliott et al. published in 2006 (B. A. Brown-Elliott, J. M. Brown, P. S. Conville, and R. J. Wallace. Jr., Clin Microbiol Rev 19:259-282, 2006, https://doi.org/10.1128/CMR.19.2.259-282.2006). Included is a discussion on the taxonomic expansion of the genus, current identification methods, and the impact of new technology (including matrix-assisted laser desorption ionization-time of flight [MALDI-TOF] and whole genome sequencing) on diagnosis and treatment. Clinical manifestations, the epidemiology, and geographic distribution are briefly discussed. An additional section on actinomycotic mycetoma is added to address this often-neglected disease.

A Case Report of Mycetoma and Cranial Osteomyelitis by Nocardia nova

Mycetoma is a chronic, localized, slowly progressive, granulomatous infection of the skin that may progress to subcutaneous tissue, muscle and bone. It is an infrequent manifestation of Nocardia infection that predominantly occurs on the lower extremities.

A previously healthy, 17-year-old boy presented to us with a 3-month history of scalp abscesses. On physical examination he had numerous, large left parietal and occipital inflammatory nodules on the scalp covered by alopecic skin and several sinuses discharging a purulent and serosanguinous material. He underwent a CT-scan and an MRI of the skull that revealed signs of cranial osteomyelitis and epidural empyema. Polymerase chain reaction assay of the purulent exudate was performed and identified Nocardia nova. The patient was discharged from the hospital after 8 weeks of antibiotherapy with meropenem and TMP-SMX with clinical, laboratorial and imaging improvement. He completed 12 months of outpatient oral therapy with TMP-SMX, after which cranial CT-scan showed a significant reduction of soft tissue thickening and bone reconstitution, with no relapses after stopping the treatment.

The best antibiotic regimen and length of treatment are not established for the management of nocardiosis. This is an unusual and severe presentation of infection by Nocardia nova with extent to the bone and epidural space, with full recovery under standard antibiotic therapy. This case shows that a good outcome may be achieved with prolonged antimicrobial treatment in an immunocompetent patient.

Mycetoma: a clinical dilemma in resource limited settings

Background

Mycetoma is a chronic mutilating disease of the skin and the underlying tissues caused by fungi or bacteria. Although recently included in the list of neglected tropical diseases by the World Health Organization, strategic control and preventive measures are yet to be outlined. Thus, it continues to pose huge public health threat in many tropical and sub-tropical countries. If not detected and managed early, it results into gruesome deformity of the limbs. Its low report and lack of familiarity may predispose patients to misdiagnosis and delayed treatment initiation. More so in situation where diagnostic tools are limited or unavailable, little or no option is left but to clinically diagnose these patients. Therefore, an overview of clinical course of mycetoma, a suggested diagnostic algorithm and proposed use of materials that cover the exposed susceptible parts of the body during labour may assist in the prevention and improvement of its management. Furthermore, early reporting which should be encouraged through formal and informal education and sensitization is strongly suggested.

Main text

An overview of the clinical presentation of mycetoma in the early and late phases, clues to distinguish eumycetoma from actinomycetoma in the field and the laboratory, differential diagnosis and a suggested diagnostic algorithm that may be useful in making diagnosis amidst the differential diagnosis of mycetoma is given. Additionally, a proposed preventive measures which may be helpful in the community is also provided. Since treatment is currently based on expert opinion, we encourage active research to establish treatment guideline for it.

Conclusion

Since delay in visiting health facility results into gruesome complication, early presentation, recognition and initiation of appropriate choice of regimen is helpful in reducing complications. The clinical overview of mycetoma and the suggested algorithm may enhance suspicion and possibly increase recognition of mycetoma in the community and further guide in differentiation of eumycetoma from actinomycetoma. There is an urgent need for research funding for mycetoma, a disease plagued by severe physical disabilities and social stigma leading to isolation.

Electronic supplementary material

The online version of this article (10.1186/s12941-018-0287-4) contains supplementary material, which is available to authorized users.

Complete genome sequence analysis of Nocardia brasiliensis HUJEG-1 reveals a saprobic lifestyle and the genes needed for human pathogenesis

Nocardia brasiliensis is an important etiologic agent of mycetoma. These bacteria live as a saprobe in soil or organic material and enter the tissue via minor trauma. Mycetoma is characterized by tumefaction and the production of fistula and abscesses, with no spontaneous cure. By using mass sequencing, we determined the complete genomic nucleotide sequence of the bacteria. According to our data, the genome is a circular chromosome 9,436,348-bp long with 68% G+C content that encodes 8,414 proteins. We observed orthologs for virulence factors, a higher number of genes involved in lipid biosynthesis and catabolism, and gene clusters for the synthesis of bioactive compounds, such as antibiotics, terpenes, and polyketides. An in silico analysis of the sequence supports the conclusion that the bacteria acquired diverse genes by horizontal transfer from other soil bacteria, even from eukaryotic organisms. The genome composition reflects the evolution of bacteria via the acquisition of a large amount of DNA, which allows it to survive in new ecological niches, including humans.