Johann Klein
Johann Klein (25 March 1788 – 11 April 1856) was professor of obstetrics at the University of Salzburg and at the University of Vienna. Johann Baptist Chiari was his son-in-law. In Vienna, he was succeeded by professor Carl Braun in 1856.

In the maternity clinic at the Vienna General Hospital there was a position as assistant to professor Klein.  The position was held by:
 Eduard Lumpe
 Franz Breit, 1843?–1847 (except 1 July 1846 – 20 October 1846, when Semmelweis was Assistent)
 Ignaz Semmelweis, 1847–1849
 Carl Braun, 1849–1853

It was normal to grant the Assistent a two-year extension; indeed both Breit and Braun were granted extensions, Semmelweis was not however.  Klein seems to have felt threatened by the younger members of the faculty, and he opposed both Semmelweis and his theories, specifically, Klein advocated the idea that physicians' hands could not transmit disease to their patients.

References

1788 births
1856 deaths
Austrian obstetricians
Academic staff of the University of Salzburg
Academic staff of the University of Vienna