Histological and microbiological aspects of actinomycetoma cases in Venezuela

Abstract

A ten year (1976-1986) review study of cases of Actinomycetoma in Venezuela was made through personal interview and clinical examinations, analysis of medical records of patients with actinomycetoma, histological studies of biopsy samples, as well as microbiological studies of isolates strain, also through out personal interviews with researchers and dermatologists who were sources of information on mycetoma cases. A total of 47 cases were recorded. As etiologic agent Actinomadura madurae was found in 20 cases - (42.5%), Nocardia brasiliensis in 13 cases (27.6%), Nocardia spp 7 cases (14.8%), Streptomyces somaliensis in 4 cases (8.5%), N. asteroides in 2 cases (4.2%) and N. otitidis caviarum, (N. caviae) in 1 case (2.1%). Most of the reported cases involved individuals living and working in rural areas, mostly males who outnumber females 4:1. The patients were 18 to 80 years old. A. madurae was reported as the most frequent etiologic agent. Most of the clinical cases were seen when the disease was well established. Twenty four of the forty seven cases reported were observed in Lara State, which represents a 51.0% of all the cases studied.

Nocardia species: host-parasite relationships

“…Pus may discharge through sinus tracts that develop. During the progressive development of the lesions, chronic granulomatous inflammation with concomitant swelling and enlargement of the surrounding areas occurs with the formation of additional, multiple secondary nodules and draining sinus tracts that exude serous fluid which may contain pus cells (583,599,600). The exudate from these sinus tracts usually contains granules that have a characteristic size, shape, and color.…”

“…The exudate from these sinus tracts usually contains granules that have a characteristic size, shape, and color. The granules represent small colonies of the infecting agent surrounded by masses of inflammatory cells (439,599,600). Usually the mycetoma remains localized but enlarges by extension of the organisms through the tissues.…”

“…With time, the infection involves both the muscle and bone, wherein a destructive osteomyelitis occurs. Once established, these lesions become relentlessly progressive over a period of years and frequently do not respond to chemotherapy (583,599,600).…”

“…Mycetomas caused by fungi are called eumycetomas, whereas those caused by the actinomycetes are actinomycetomas (305,599,600,604,659,669). At least half of the mycetomas reported in the world literature are caused by actinomycetes, and the majority of these are caused by Nocardia spp.…”

“…At least half of the mycetomas reported in the world literature are caused by actinomycetes, and the majority of these are caused by Nocardia spp. Members of the genus Actinomadura are the most frequently reported causes of actinomycetoma in certain geographic locations (599,600), whereas other actinomycetes such as Streptomyces spp. may cause mycetomas in other geographic areas (305,599,600,604,659,669 (78).…”