Immunologic tests in the diagnosis of pulmonary infection

Using in situ hybridization to detect endosymbiont Wolbachia in dissected tissues of mosquito host

The endosymbiont Wolbachia, extensively occurring in arthropods, usually causes reproductive distortions of the host, such as mosquitoes. In past years, detection of Wolbachia in host tissues has highly relied on transmission electron microscopy (TEM) that is tedious and usually unable to gain satisfactory results without experienced techniques and expensive instruments. Polymerase chain reaction (PCR) recently has become popular in Wolbachia identification. However, necessity of DNA extraction from host individuals or dissected tissues has limited its application in extensiveness and versatility. At present, in situ hybridization has increased its role in examination of various microbes. This report provides a technique for rapid detection and localization of Wolbachia in tissues dissected from mosquitoes and possibly other infected organisms. To detect Wolbachia and to localize them in host tissues more precisely, in situ hybridization by using digoxigenin (DIG)-labeled probes was invented and applied to Wolbachia detection in this study. The results showed that Wolbachia preferentially aggregate in ovarioles, which is consistent with previous observations by TEM. The endobacteria also were detected in salivary glands, mostly in lateral lobes. Ultrastructurally, Wolbachia has been shown to occur in the cytoplasma of salivary gland cells.

Blastomycosis in Quebec (1981-90): Report of 23 cases and review of published cases from Quebec

Twenty-three cases of blastomycosis were reported in a survey conducted in the province of Quebec from 1981-90. Thirteen patients resided south of the St Lawrence River and the other 10, north. Two small geographical clusters were apparent in and around the cities of Sherbrooke and Quebec. The male to female ratio was 1.6:1 and the median age was 47 years (range 26 to 77). Lung involvement was observed in 19 cases and was the only site involved in 11. Cutaneous manifestations were reported in 11 cases while bone infection (three cases) and central nervous system (CNS) infections were also noted. Diagnosis was confirmed by culture in 21 cases and by histopathology in two cases. Of the 21 culture-positive cases, 12 strains of Blastomyces dermatitidis were isolated from lungs, nine from skin, and one each from bone and brain. Serodiagnostic tests by immunodiffusion or complement fixation were positive for only one of the 10 patients known to have been tested. Ten patients were treated with amphotericin B, 11 with ketoconazole, one with fluconazole and eight underwent surgery. While amphotericin B was used in eight of the 10 earliest treated cases, ketoconazole was administered in 10 of the 13 more recent cases. Of the patients for whom follow-up data have been obtained, 21 are reported cured (one of whom was not treated) and one patient died of another cause. This survey confirms that blastomycosis is a rare disease in this endemic area and that patterns of therapy are changing.