Dochez developed a biological classification of types of pneumococci. There is controversy whether this was the same pneumococci or a mix of the two. In 1900 Neufeld discovered bile solubility of pneumococci. Streptococcal infection was a frequent coinfection complicating recovery from lobar pneumonia by pneumococci infection. Beta-hemolytic streptococci, pneumococci, staphylococci, and enterococci are usually susceptible to macrolides. With Oswald Avery, he discovered the soluble substance that confers type-specificity upon pneumococci. They differ from pneumococci in that they are optochin resistant and are not bile soluble. Pneumococci are typically gram-positive cocci seen in pairs or chains.