Table 1.
Zone of inhibition (mm) of different antibiotics against pathogenic microorganisms in the presence and absence of AgNPs
| Antibiotic |
Escherichia coli ATCC 25922 |
Acinetobacter baumannii AIIMS 7 |
Enterobacter aerogenes NCIM 2964 |
Pseudomonas aeruginosa NCIM 5029 |
Shigella sonnie MTCC 2957 |
Salmonella typhimurium NCIM 2501 |
Staphylococcus aureus MTCC 3160 |
Streptococcus mutans MTCC 497 |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | A | B | C | A | B | C | A | B | C | A | B | C | A | B | C | A | B | C | A | B | C | |
| Aminoglycosides | ||||||||||||||||||||||||
| Amikacin | 23.0 | 25.0 | 0.2 | 6.0 | 8.0 | 0.8 | 23.0 | 23.0 | 0.0 | 26.0 | 27.0 | 0.1 | 24.0 | 25.0 | 0.1 | 15.0 | 17.0 | 0.3 | 20.0 | 21.0 | 0.1 | 24.0 | 26.0 | 0.2 |
| Gentamicin | 28.0 | 30.0 | 0.1 | 6.0 | 10.0 | 1.8 | 23.0 | 25.0 | 0.2 | 28.0 | 30.0 | 0.1 | 20.0 | 23.0 | 0.3 | 20.0 | 20.0 | 0.0 | 20.0 | 20.0 | 0.0 | 25.0 | 25.0 | 0.0 |
| Kanamycin | 22.0 | 22.0 | 0.0 | 6.0 | 6.0 | 0.0 | 18.0 | 20.0 | 0.2 | 6.0 | 10.0 | 1.8 | 20.0 | 22.0 | 0.2 | 19.0 | 20.0 | 0.1 | 19.0 | 20.0 | 0.1 | 14.0 | 18.0 | 0.6 |
| β-Iactams | ||||||||||||||||||||||||
| Amoxicillin | 14.0 | 14.0 | 0.0 | 6.0 | 6.0 | 0.0 | 14.0 | 17.0 | 0.5 | 6.0 | 10.0 | 1.8 | 6.0 | 8.0 | 0.8 | 23.0 | 23.0 | 0.0 | 6.0 | 6.0 | 0.0 | 10.0 | 12.0 | 0.4 |
| Ampicillin | 18.0 | 20.0 | 0.2 | 6.0 | 8.0 | 0.8 | 16.0 | 19.0 | 0.4 | 6.0 | 7.0 | 0.4 | 8.0 | 10.0 | 0.6 | 25.0 | 25.0 | 0.0 | 9.0 | 13.0 | 1.1 | 12.0 | 13.0 | 0.2 |
| Penicillin | 15.0 | 16.0 | 0.1 | 6.0 | 6.0 | 0.0 | 20.0 | 22.0 | 0.2 | 6.0 | 7.0 | 0.4 | 10.0 | 10.0 | 0.0 | 23.0 | 25.0 | 0.2 | 6.0 | 6.0 | 0.0 | 6.0 | 12.0 | 3.0 |
| Cephalosporins | ||||||||||||||||||||||||
| Ceftazidime | 28.0 | 28.0 | 0.0 | 6.0 | 6.0 | 0.0 | 30.0 | 30.0 | 0.0 | 29.0 | 31.0 | 0.1 | 25.0 | 25.0 | 0.0 | 32.0 | 33.0 | 0.1 | 23.0 | 25.0 | 0.2 | 11.0 | 13.0 | 0.4 |
| Ceftriaxone | 27.0 | 30.0 | 0.2 | 6.0 | 6.0 | 0.0 | 34.0 | 35.0 | 0.1 | 23.0 | 23.0 | 0.0 | 20.0 | 25.0 | 0.6 | 30.0 | 32.0 | 0.1 | 20.0 | 25.0 | 0.6 | 14.0 | 14.0 | 0.0 |
| Glycopeptides | ||||||||||||||||||||||||
| Vancomycin | 7.0 | 9.0 | 0.6 | 7.0 | 10.0 | 1.0 | 11.0 | 24.0 | 3.8 | 6.0 | 8.0 | 0.8 | 9.0 | 10.0 | 0.2 | 10.0 | 12.0 | 0.4 | 6.0 | 8.0 | 0.8 | 16.0 | 16.0 | 0.0 |
| Quinolones | ||||||||||||||||||||||||
| Ciprofloxacin | 35.0 | 36.0 | 0.1 | 18.0 | 19.0 | 0.1 | 30.0 | 32.0 | 0.1 | 35.0 | 35.0 | 0.0 | 33.0 | 35.0 | 0.1 | 25.0 | 26.0 | 0.1 | 27.0 | 28.0 | 0.1 | 25.0 | 27.0 | 0.2 |
| Tetracyclines | ||||||||||||||||||||||||
| Doxycycline | 25.0 | 2.0 | 0.0 | 20.0 | 23.0 | 0.3 | 25.0 | 27.0 | 0.2 | 8.0 | 12.0 | 1.2 | 19.0 | 20.0 | 0.1 | 22.0 | 24.0 | 0.2 | 16.0 | 19.0 | 0.4 | 24.0 | 29.0 | 0.5 |
| Tetracycline | 28.0 | 30.0 | 0.1 | 20.0 | 20.0 | 0.0 | 30.0 | 30.0 | 0.0 | 15.0 | 18.0 | 0.4 | 27.0 | 28.0 | 0.1 | 24.0 | 24.0 | 0.0 | 21.0 | 23.0 | 0.2 | 21.0 | 21.0 | 0.0 |
| Others | ||||||||||||||||||||||||
| Chloramphenicol | 27.0 | 30.0 | 0.2 | 14.0 | 15.0 | 0.1 | 32.0 | 34.0 | 0.1 | 11.0 | 16.0 | 1.1 | 30.0 | 23.0 | 0.1 | 28.0 | 28.0 | 0.0 | 6.0 | 6.0 | 0.0 | 22.0 | 22.0 | 0.0 |
| Trimethoprim | 26.0 | 28.0 | 0.2 | 7.0 | 9.0 | 0.6 | 30.0 | 32.0 | 0.1 | 6.0 | 9.0 | 1.2 | 30.0 | 30.0 | 0.0 | 21.0 | 21.0 | 0.0 | 25.0 | 26.0 | 0.1 | 6.0 | 6.0 | 0.0 |
Notes: Increase (C) was calculated using the formula B2−A2/A2, where A and B are the zone of inhibition (mm) obtained for antibiotic alone and antibiotic in combination with AgNPs, respectively. In case of no zone of inhibition, diameter of the disc (6 mm) was taken for the calculation. All experiments were repeated twice, and standard deviations were negligible.
Abbreviation: AgNPs, silver nanoparticles.