Full text
PDFPage 1438
. 1986 Dec;52(6):1438. doi: 10.1128/aem.52.6.1438-1438.1986
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.