Chitin, a polymer ofN-acetylglucosamine, is an essential component of the fungal cell wall. Chitosan, a deacetylated form of chitin, is also important in maintaining cell wall integrity and is essential forCryptococcus neoformansvirulence. In their article, Gilbert et al. [N. M. Gilbert, L. G. Baker, C. A. Specht, and J. K. Lodge, mBio 3(1):e00007-12, 2012] demonstrate that the enzyme responsible for chitosan synthesis, chitin deacetylase (CDA), is differentially attached to the cell membrane and wall. Bioactivity is localized to the cell membrane, where it is covalently linked via a glycosylphosphatidylinositol (GPI) anchor. Findings from this study significantly enhance our understanding of cryptococcal cell wall biology. Besides the role of chitin in supporting structural stability, chitin and host enzymes with chitinase activity have an important role in host defense and modifying the inflammatory response. Thus, chitin appears to provide a link between the fungus and host that involves both innate and adaptive immune responses. Recently, there has been increased attention to the role of chitinases in the pathogenesis of allergic inflammation, especially asthma. We review these findings and explore the possible connection between fungal infections, the induction of chitinases, and asthma.

Cryptococcosis during pregnancy is well documented, but transmission of infection to the fetus is rare. We describe a premature neonate born to a mother with congenitally acquired human immunodeficiency virus (HIV) and active cryptococcosis. Histological examination of the placenta revealed Cryptococcus neoformans within the maternal intervillous space with focal invasion into the chorionic villi. A positive serum cryptococcal antigen (1:2) was detected on days 1 and 5 of life. The neonate had no evidence of central nervous system disease and was treated with fluconazole with resolution of antigenemia. This case highlights both the potential for transplacental transmission of C. neoformans infection and the complexities of caring for pregnant mothers who themselves are congenitally infected with HIV.