A compound for use in treating bacterial or fungal infections in mammals, wherein the compound is represented by the general Formula or a pharmaceutically acceptable salt thereof wherein R 1 is selected from the group consisting of a substituted or unsubstituted alkyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 4 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted cycloalkenyl group having from 4 to 12 carbon atoms, a substituted or unsubstituted alkynyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a group having 4 to 11 carbon atoms selected from aralkyl groups, whereby the aralkyl group is an alkyl group at least one hydrogen atom of which is replaced by an aryl or heteroaryl group, or alkyl groups substituted with cycloalkenyl groups, such as benzyl groups, 1- or 2-phenylethyl groups, and 2-(5-methylfuran-2-yl)propyl groups, R 2 to R 5 are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a halogen atom, a trifluoromethyl group, -NE 1 E 2, -NO 2, -CN, -OE 3, -C E 4, -C NE 5 E 6, -COOE 7, and -SO 3 E 8, wherein E 1 to E 8 are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, and X is S, Y is O, and Z is OH; or X is NH, Y is N-OH or S, and Z is a hydrogen atom or OH. R 1 is selected from the group consisting of a substituted or unsubstituted alkyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 4 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted cycloalkenyl group having from 4 to 12 carbon atoms, a substituted or unsubstituted alkynyl group having from 4 to 11 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and a group having 4 to 11 carbon atoms selected from aralkyl groups, whereby the aralkyl group is an alkyl group at least one hydrogen atom of which is replaced by an aryl or heteroaryl group, or alkyl groups substituted with cycloalkenyl groups, such as benzyl groups, 1- or 2-phenylethyl groups, and 2-(5-methylfuran-2-yl)propyl groups, R 2 to R 5 are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a halogen atom, a trifluoromethyl group, -NE 1 E 2, -NO 2, -CN, -OE 3, -C E 4, -C NE 5 E 6, -COOE 7, and -SO 3 E 8, wherein E 1 to E 8 are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, and X is S, Y is O, and Z is OH; or X is NH, Y is N-OH or S, and Z is a hydrogen atom or OH.