Loeffler, Friedrich (1852–1915)

German bacteriologist. He helped pioneer immunology, particularly in the treatment of diphtheria. He introduced a preventive vaccine against animal foot-and-mouth disease. He also isolated Salmonella typhimurium, an organism causing food poisoning.

He was born in Frankfurt am Oder, and studied medicine at Wurzburg and Berlin. He served for some years as a Prussian army surgeon. In 1879 he took charge of the health office in Berlin, where he made important bacteriological discoveries with R. Koch and G. Gaffky. Loeffler cultured the diphtheria bacillus (1884) recently discovered by Klebs and later called ‘Klebs-Loeffler bacillus’. He discovered the causal organism of glanders and swine erysipelas in 1886. He also showed that foot-and-mouth disease is caused by a filterable virus (1897). He introduced a vaccine against this disease in 1899. He also made important contributions to microscopical technique. In 1913 he became director of the Koch Institute for Infectious Diseases, Berlin.