Detection of Metallo-β-lactamase (MBL) among Carbapenem-Resistant Gram-Negative Bacteria from Rectal Swabs of Cow and Cloacae Swabs of Poultry Birds Ejikeugwu Chika1*, Esimone Charles2, Iroha Ifeanyichukwu1, Okonkwo Eucharia C1, Gugu Thaddeus2, Oli Angus N2, Ugwu Malachy2, Ezeador Chika3 and Moses N Ikegbunam2