Table 2.
Isolates and antibiotic sensitivities in 68 Gram-positive culture-confirmed endophthalmitis cases following phacoemulsification surgery (number sensitive / number tested).
| Antibiotic |
Coagulase -negative Staphyloc occus N=34 |
Methicillin- resistant Staphyloc occus aureus N=6 |
Methicillin- sensitive Staphyloc occus aureus N=5 |
Streptoco ccus viridans N=13 |
Streptoco ccus species N=5 |
Enteroco ccus N=5 |
|---|---|---|---|---|---|---|
|
Cephalospor ins |
||||||
| Cefazolin | 13/13 | 0/3 | 2/3 | 4/4 | 1/1 | 0/1§ |
| Ceftazidime | 6/17 | 0/3 | 0/1 | 1/2 | 1/1 | 0/1 |
| Ceftriaxone | 9/16 | 0/3 | 1/1 | 9/9 | 2/2 | 0/1 |
| Cefuroxime | 7/12 | 1/3 | -- | -- | 1/1 | 0/1 |
| Cephalothin | 15/15 | 3/3 | 1/1 | 3/3 | 1/1 | 0/1 |
|
Fluoroquinol ones † |
||||||
| Ciprofloxacin | 11/18 | 0/4 | 1/1 | 0/3 | 1/1 | 1/3 |
| Gatifloxacin (surrogate for moxifloxacin) |
7/12 | 1/3 | 2/2 | 6/7 | 1/2 | 2/3 |
| Ofloxacin | 8/14 | 0/3 | 2/3 | 8/8 | 1/2 | 0/1 |
|
Aminoglycos ides |
||||||
| Gentamicin | 19/19 | 4/4 | 3/3 | 3/5 | 0/1 | 0/1§ |
| Amikacin | 14/15 | 1/3 | 1/1 | 0/4 | 0/1 | 0/2§ |
| Neomycin | 13/14 | 0/3 | 3/3 | 0/8 | 0/2 | 0/2§ |
| Tobramycin | 5/5 | 0/1 | 1/1 | 1/1 | -- | -- |
| Polypeptides | ||||||
| Bacitracin | 11/14 | 1/3 | 2/3 | 8/8 | 2/2 | 1/2 |
| Polymyxin B | 8/14 | 0/3 | 0/3 | 0/8 | 0/2 | 0/2 |
| Other | ||||||
| Clindamycin | 27/32 | 0/6 | 2/3 | 6/6 | 4/4 | 0/1§ |
| Oxacillin‡ | 18/30 | 0/6 | 3/3 | 2/5 | 2/3 | 0/1 |
| Sulfisoxazole | 11/14 | 2/3 | 2/3 | 1/3 | 1/1 | 0/1 |
| Tetracycline | 20/22 | 3/3 | 3/3 | 1/2 | 0/1 | -- |
| Trimethoprim | 11/14 | 3/3 | 3/3 | 2/4 | 0/1 | 1/1§ |
| Vancomycin | 32/32 | 6/6 | 5/5 | 9/10 | 5/5 | 4/4 |
Staphylococcus or streptococcus species which are susceptible to gatifloxacin (or ciprofloxacin or ofloxacin) are considered susceptible to moxifloxacin because moxifloxacin has the greatest Gram-positive activity.
If a Staphylococcus organism is sensitive to oxacillin, it is considered sensitive to all the cephalosporins. If it is resistant to oxacillin, it is considered resistant to all the cephalosporins.
Enterococcus is considered intrinsically resistant to cephalosporins, clindamycin and trimethoprim. Organisms tested as sensitive to trimethoprim may have in vitro activity, but trimethoprim is not clinically effective against Enterococcus. In addition, aminoglycosides are not effective against Enterococcus even if in vitro testing suggests susceptibility; higher doses would be required and would need to be specifically tested.