Extra-intestinal salmonellosis in a tertiary care center in South India.

INTRODUCTION: The present study is a retrospective analysis of a total of 36 cases of bacteriologically proven extra-intestinal salmonellosis, managed at Nizam's Institute of Medical Sciences, between 1987 and 2012 (25 years). The extra-intestinal sites involved were the skin, cerebrum, spleen, ovary, synovium, and the skeletal muscle. METHODOLOGY: The extra-intestinal specimens were first processed using standard methods. Colonies suspected as Salmonella were identified by standard laboratory methods, initially by manual biochemical reactions and later by the API system (bioMerieux, Marcy l'Etoile- France) and the Vitek-2 system (bioMerieux). All the Salmonella isolates were sent to Central Research Institute, Kasauli, for serotyping. RESULTS: The predominant serotype isolated was Salmonella Typhi (S. Typhi) in 27 (75%) patients, followed by Salmonella Senftenberg (S. Senftenberg) in 5 (14%), Salmonella Paratyphi A (S. Paratyphi A) in 3 (8%), and Salmonella Typhimurium (S. Typhimurium) in 1 (3%). There was an increasing resistance to ampicillin, chloramphenicol, cephalosporins (third generation), and quinolones over the 25 years. CONCLUSIONS: The diagnosis of extra-intestinal salmonellosis requires a high degree of clinical suspicion and should be included in the differential diagnosis in patients with deep-seated abscesses.

Diagnostic utility of melanin production by fungi: study on tissue sections and culture smears with Masson-Fontana stain.

BACKGROUND: Dematiaceous fungi appear brown in tissue section due to melanin in their cell walls. When the brown color is not seen on routine H and E and culture is not available, differentiation of dematiaceous fungi from other fungi is difficult on morphology alone. AIMS AND OBJECTIVE: To study if melanin production by dematiaceous fungi can help differentiate them from other types of fungi. MATERIALS AND METHODS: Fifty tissue sections of various fungal infections and 13 smears from cultures of different species of fungi were stained with Masson Fontana stain to assess melanin production. The tissue sections included biopsies from 26 culture-proven fungi and 24 biopsies of filamentous fungi diagnosed on morphology alone with no culture confirmation. RESULTS: All culture-proven dematiaceous fungi and Zygomycetes showed strong positivity in sections and culture smears. Aspergillus sp showed variable positivity and intensity. Cryptococcus neoformans showed strong positivity in tissue sections and culture smears. Tissue sections of septate filamentous fungi (9/15), Zygomycetes (4/5), and fungi with both hyphal and yeast morphology (4/4) showed positivity for melanin. The septate filamentous fungi negative for melanin were from biopsy samples of fungal sinusitis including both allergic and invasive fungal sinusitis and colonizing fungal balls. CONCLUSION: Melanin is produced by both dematiaceous and non-dematiaceous fungi. Masson-Fontana stain cannot reliably differentiate dematiaceous fungi from other filamentous fungi like Aspergillus sp; however, absence of melanin in the hyphae may be used to rule out dematiaceous fungi from other filamentous fungi. In the differential diagnosis of yeast fungi, Cryptococcus sp can be differentiated from Candida sp by Masson-Fontana stain in tissue sections.