| Gram-positive organisms | 
|---|
| Enterococcus faecalis | Ampicillin, vancomycin/teicoplanin | 
| Enterococcus faecium | Vancomycin/teicoplanin, linezolid
Glycopeptide-resistant enterococci
Linezolid, tigecycline, daptomycin | 
| MRSA | Clindamycin, vancomycin, rifampicin (never used as monotherapy), linezolid, daptomycin, tetracyclines, tigecycline, co-trimoxazole | 
| Staphylococcus aureus | Flucloxacillin, clindamycin | 
| Streptococcus pyogenes | Penicillin, clindamycin, vancomycin | 
| Streptococcus pneumoniae | Penicillin, cephalosporins, levofloxacin, vancomycin | 
| Gram-negative organisms | 
|---|
| Escherichia coli, coliforms (enteric Gram-negative bacilli) | Amoxicillin, Trimethoprim, cefuroxime, Ciprofloxacin, Co-Amoxiclav | 
| Enterobacter spp., Citrobacter spp. | Ciprofloxacin, meropenem, ertapenem, aminoglycosides | 
| ESBL-producing Enterobacteriaceae | Ciprofloxacin, meropenem, ertapenem (if sensitive), temocillin, aminoglycosides | 
| Carbapenemase-producing Enterobacteriaceae | Ciprofloxacin, aminoglycosides, tigecycline, colistin | 
| Haemophilus influenzae | Amoxicillin, Co-Amoxiclav, macrolides, cefuroxime, cefotaxime, Ciprofloxacin | 
| Legionella pneumophila | Azithromycin, levofloxacin, doxycycline | 
| Neisseria gonorrhoeae | Ceftriaxone/cefixime, spectinomycin | 
| Neisseria meningitidis | Penicillin, cefotaxime/ceftriaxone, chloramphenicol | 
| Pseudomonas aeruginosa | Ciprofloxacin, piperacillin-tazobactam, aztreonam, meropenem, aminoglycosides, ceftazidime/cefepime | 
| Salmonella typhi | Ceftriaxone, azithromycin (uncomplicated typhoid), chloramphenicol (resistance common) | 
| Strict anaerobes | 
|---|
| Bacteroides spp. | Metronidazole, clindamycin, Co-Amoxiclav, piperacillin-tazobactam, meropenem | 
| Clostridioides difficile | Metronidazole, vancomycin (oral), fidaxomicin | 
| Clostridium spp. | Penicillin, Metronidazole, clindamycin | 
| Fusobacterium spp. | Penicillin, Metronidazole, clindamycin | 
| Other organisms | 
|---|
| Chlamydia trachomatis | Azithromycin, doxycycline | 
| Treponema pallidum | Penicillin, doxycycline |