Antibodies against

1. An isolated recombinant monoclonal antibody that binds to Clostridium difficile toxin B, wherein said antibody comprises a heavy chain variable domain and a light chain variable domain, and:

(a) wherein the heavy chain variable domain comprises a complementarity determining region 1 (CDR1) comprising the amino acid sequence of SEQ ID NO:96; a CDR2 comprising the amino acid sequence of SEQ ID NO:98; and a CDR3 comprising the amino acid sequence of SEQ ID NO:100; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:103; a CDR2 comprising the amino acid sequence of SEQ ID NO:105; and a CDR3 comprising the amino acid sequence of SEQ ID NO:107;

(b) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:114; a CDR2 comprising the amino acid sequence of SEQ ID NO:116; and a CDR3 comprising the amino acid sequence of SEQ ID NO:118; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:121; a CDR2 comprising the amino acid sequence of SEQ ID NO:123; and a CDR3 comprising the amino acid sequence of SEQ ID NO:125;

(c) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:132; a CDR2 comprising the amino acid sequence of SEQ ID NO:134; and a CDR3 comprising the amino acid sequence of SEQ ID NO:136; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:139; a CDR2 comprising the amino acid sequence of SEQ ID NO:141; and a CDR3 comprising the amino acid sequence of SEQ ID NO:143;

(d) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:150; a CDR2 comprising the amino acid sequence of SEQ ID NO:152; and a CDR3 comprising the amino acid sequence of SEQ ID NO:154; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:157; a CDR2 comprising the amino acid sequence of SEQ ID NO:159; and a CDR3 comprising the amino acid sequence of SEQ ID NO:161;

(e) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:168; a CDR2 comprising the amino acid sequence of SEQ ID NO:170; and a CDR3 comprising the amino acid sequence of SEQ ID NO:172; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:175; a CDR2 comprising the amino acid sequence of SEQ ID NO:177; and a CDR3 comprising the amino acid sequence of SEQ ID NO:179; or

(f) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:186; a CDR2 comprising the amino acid sequence of SEQ ID NO:188; and a CDR3 comprising the amino acid sequence of SEQ ID NO:190; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:193; a CDR2 comprising the amino acid sequence of SEQ ID NO:195; and a CDR3 comprising the amino acid sequence of SEQ ID NO:197.

2. The isolated recombinant monoclonal antibody of claim 1 ,

(a) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:92 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:94;

(b) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:110 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:112;

(c) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:128 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:130;

(d) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:146 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:148;

(e) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:164 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:166; or

(f) wherein the heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:182 and the light chain variable domain comprises the amino acid sequence of SEQ ID NO:184.

3. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody comprises at least one of the following characteristics:

(a) the antibody binds to C. difficile toxin B with a dissociation constant (K D ) equal to or less than 100 pM;

(b) the antibody neutralizes the in vitro cytotoxicity of C. difficile toxin B in the Vero monkey kidney cell line with an NT50 equal to or less than 1000 pM;

(c) the antibody neutralizes the C. difficile toxin B induced loss of transepithelial resistance (TEER) in the T-84 cell line with an NT50 equal to or less than 200 pM; or

(d) the antibody binds to toxin B produced by at least the strains of toxinotypes 0, III, and V.

4. The isolated recombinant monoclonal antibody of claim 3 , wherein the antibody binds to toxin B produced by at least the strains of toxinotypes 0, III, V, and VIII, toxin B produced by at least the strains of toxinotypes 0, III, V, VIII, and XII, or toxin B produced by at least the strains of toxinotypes 0, III, V, VIII, XII, and XV.

5. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is a human antibody.

6. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is a bispecific antibody, wherein the bispecific antibody comprises 1) a first antigen binding site comprising a heavy chain variable domain and a light chain variable domain

(a) wherein the heavy chain variable domain comprises a complementarity determining region 1 (CDR1) comprising the amino acid sequence of SEQ ID NO:6; a CDR2 comprising the amino acid sequence of SEQ ID NO:8; and a CDR3 comprising the amino acid sequence of SEQ ID NO:10; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:13; a CDR2 comprising the amino acid sequence of SEQ ID NO:15; and a CDR3 comprising the amino acid sequence of SEQ ID NO:17;

(b) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:24; a CDR2 comprising the amino acid sequence of SEQ ID NO:26; and a CDR3 comprising the amino acid sequence of SEQ ID NO:28; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:31; a CDR2 comprising the amino acid sequence of SEQ ID NO:33; and a CDR3 comprising the amino acid sequence of SEQ ID NO:35;

(c) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:42; a CDR2 comprising the amino acid sequence of SEQ ID NO:44; and a CDR3 comprising the amino acid sequence of SEQ ID NO:46; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:49; a CDR2 comprising the amino acid sequence of SEQ ID NO:51; and a CDR3 comprising the amino acid sequence of SEQ ID NO:53;

(d) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:60; a CDR2 comprising the amino acid sequence of SEQ ID NO:62; and a CDR3 comprising the amino acid sequence of SEQ ID NO:64; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:67; a CDR2 comprising the amino acid sequence of SEQ ID NO:69; and a CDR3 comprising the amino acid sequence of SEQ ID NO:71; or

(e) wherein the heavy chain variable domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO:78; a CDR2 comprising the amino acid sequence of SEQ ID NO:80; and a CDR3 comprising the amino acid sequence of SEQ ID NO:82; and wherein the light chain variable domain comprises: a CDR1 comprising the amino acid sequence of SEQ ID NO:85; a CDR2 comprising the amino acid sequence of SEQ ID NO:87; and a CDR3 comprising the amino acid sequence of SEQ ID NO:89, and wherein the heavy chain variable domain of said antibody is linked to a human constant region, and

2) a second antigen binding site comprising the heavy chain variable domain and light chain variable domain of the antibody of claim 1 .

7. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is a bispecific antibody, wherein the bispecific antibody comprises 1) a first antigen binding site comprising the heavy chain variable domain and light chain variable domain of a B1 antibody and 2) a second antigen binding site comprising the heavy chain variable domain and light chain variable domain of a B2 antibody.

8. A composition comprising the isolated recombinant monoclonal antibody of claim 1 that binds to C. difficile toxin B.

9. The composition of claim 8 , further comprising at least one antibody that binds to C. difficile toxin A, wherein the at least one antibody that binds to C. difficile toxin A is one or more of A1, A2, A3, A4, and A5 antibodies.

10. The composition of claim 8 , further comprising at least one antibody that binds to C. difficile toxin A and wherein the antibody that binds to C. difficile toxin B is one or more of a B1, B2, B3, B4, B5, and B6 antibody.

11. The composition of claim 8 , further comprising a pharmaceutically acceptable excipient.

12. A method of treating a C. difficile infection, comprising administering to a subject one or more of the isolated recombinant monoclonal antibodies of claim 1 in an amount effective to treat the C. difficile infection.

13. A method of treating a C. difficile infection, comprising administering to a subject the composition of claim 8 in an amount effective to treat the C. difficile infection.

14. The method of claim 12 , wherein the subject is a human.

15. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is expressed from a transgenic animal.

16. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is expressed from an insect cell, a Chinese Hamster Ovary cell or a Human Embryonic Kidney 293T cell.

17. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is expressed from a Chinese Hamster Ovary cell.

18. The isolated recombinant monoclonal antibody of claim 1 , wherein the heavy chain variable domain of the antibody is linked to a human constant region and wherein a source of the heavy chain variable domain and the light chain variable domain is different from a source of the human constant region.

19. The isolated recombinant monoclonal antibody of claim 1 , wherein the antibody is labeled.