Johann Klein (1788–1856) 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:
It was normal to grant the Assistent a two-year extension; indeed both Breit and Braun were granted extensions, Semmelweis was not however.[1] Klein seems to have felt threatened by the younger members of the faculty, and he opposed both Semmelweis and his theories. Semmelweis, Ignaz; K. Codell Carter (translator and extensive foreword) (1861). Etiology, Concept and Prophylaxis of Childbed Fever. University of Wisconsin Press, September 15, 1983. ISBN 0299093646. p61 footnote 1