7.beta.-Amino-3-thio-3-cephem-4-carboxylic acid compounds, and antibacterial compositions and methods using them

A compound of the formula ##STR12## wherein R.sub.1.sup.a denotes hydrogen, cyanoacetyl, or an acyl group of the formula ##STR13## wherein X denotes oxygen or sulfur and, if m represents zero or 1, R.sub.a denotes phenyl, hydroxyphenyl, hydroxyphenyl protected by tert.-butoxycarbonyl or 2,2,2-trichloroethoxycarbonyl, hydroxy-chlorophenyl, hydroxy-chlorophenyl protected by tert.-butoxycarbonyl or 2,2,2-trichloroethoxycarbonyl, thienyl, 5-aminomethyl-2-thienyl, pyridyl, amino pyridinium, furyl, isothiazolyl, tetrazolyl, 1-cyclohexenyl, or 1,4-cyclohexadienyl, and R.sub.b and R.sub.c each represents hydrogen, or, if m represents zero, R.sub.a denotes phenyl, hydroxyphenyl, hydroxyphenyl protected by tert.-butoxycarbonyl or 2,2,2-trichloroethoxycarbonyl, hydroxy-chlorophenyl, hydroxy-chlorophenyl protected by tert.-butoxycarbonyl or 2,2,2-trichloroethoxycarbonyl, thienyl, 5-aminoethyl-2-thienyl, pyridyl, aminopyridinium, furyl, isothiazolyl, tetrazolyl, 1-cyclohexenyl or 1,4-cyclohexadienyl, R.sub.b denotes amino, tert.-butoxycarbonylamino, 2-halogeno-lower-alkoxycarbonylamino, lower alkoxyphenyl-lower alkoxycarbonylamino, phenyl-lower alkoxycarbonylamino, dihydroxy-triazinylcarbonylamino, 3-guanylureido, sulfoamino, tritylamino, 2-nitrophenylthioamino, 4-methylphenylsulfonylamino, 1-lower alkoxycarbonyl-2-propylideneamino, carboxyl, phenyl-lower alkoxycarbonyl, sulfo, hydroxyl, tert.-butoxycarbonyloxy, 2-halogen-lower alkoxycarbonyloxy, formyloxy, o-lower alkylphosphono, o,o'-di-lower alkylphosphono, 5-amino-5-carboxy-valeryl, 5-amino-5-carboxy-valeryl, wherein 5-amino is protected by lower alkanoyl, halogeno-lower alkanoyl, benzoyl or phthaloyl and 5-carboxy is protected by phenyl-lower alkoxycarbonyl, or 5-amino-5-carboxy-valeryl, wherein 5-carboxy is protected by phenyl-lower alkoxy and R.sub.c denotes hydrogen, or, if m represents zero, R.sub.a denotes phenyl, 2-thienyl, or 2-furyl and R.sub.b and R.sub.c conjointly denote lower alkoxyimino, cycloalkoxyimino or phenylalkoxyimino in the synconfiguration R.sub.1.sup.b denotes hydrogen, R.sub.2 represents hydroxyl, lower alkoxy, tert.-butoxy, 2-halogeno-lower alkoxy, diphenylmethoxy, lower alkoxy-diphenylmethoxy, or tri-lower alkylsilyloxy, and R.sub.3 represents lower alkyl, amino lower alkyl, tert.-amino-lower alkyl, wherein the tert.-amino group is separated from the sulfur atom by at least two carbon atoms, etherified hydroxy-lower alkyl, wherein etherified hydroxy is lower alkoxy and separated from the sulfur atom by at least two carbon atoms, carbo-lower alkoxy-lower alkyl, or lower alkenyl or halogenmethyl, the 1-oxide of such 3-cephem compound of the formula IA, the corresponding 2-cephem compound of the formula IB, ##STR14## wherein R.sub.1.sup.a, R.sub.1.sup.b, R.sub.2 and R.sub.3 have the meanings indicated under formula IA, a 3-S-oxide thereof or a pharmaceutically acceptable salt of such compound.