Table 2.

β-Lactam antibiotic spectrum of activity and infectious diseases treated (7)

Antibiotic ClassSpectrum of ActivityCommonly Treated Infectious Diseases
Gram-PositiveGram-Negative
Penicillinβ-Hemolytic streptococci +++No activityPharyngitis
Viridans streptococci ++Endocarditis
Streptococcus pneumoniae ++Neurosyphilis
Osteomyelitis
AminopenicillinsSee penicillin, plusPharyngitis
 AmoxicillinEnterococcus faecalis +++Haemophilus influenza ++Lower respiratory tract infections
 AmpicillinListeria monocytogenes +++Escherichia coli +Genitourinary tract infections
Proteus mirabilis +Skin/skin structure infections
Endocarditis (ampicillin)
Osteomyelitis (ampicillin)
Prosthetic joint infection (ampicillin)
Aminopenicillins with β-lactamase inhibitorsSee aminopenicillins, plusBite wounds (animal/human)
 Amoxicillin-clavulanateMSSA ++Proteus mirabilis +++Pneumonia, community-acquired
 Ampicillin-sulbactamHaemophilus influenzae +++Intra-abdominal infections
Escherichia coli ++Urinary tract infections
Moraxella catarrhalis ++Diabetic foot infections
Klebsiella sp. ++
Acinetobacter sp. +(sulbactam component)
Anaerobes:
Bacteroides fragilis +++
Antipseudomonal penicillinsSee aminopenicillins and aminopenicillins with β-lactamase inhibitors, plusBloodstream infections (Gram-negative bacteremia)
 Piperacillin-tazobactamEscherichia coli +++Intra-abdominal infections
Klebsiella sp. +++Diabetic foot infections
Enterobacter sp. ++Febrile neutropenia
Citrobacter sp. ++Pneumonia, hospital-acquired or ventilator-associated
Pseudomonas aeruginosa ++Sepsis and septic shock (broad-spectrum coverage)
Urinary tract infections, complicated
Skin and soft tissue infection, necrotizing (broad-spectrum coverage)
Cephalosporins
 First generationStreptococci +++Escherichia coli ++Endocarditis (cefazolin)
  CephalexinMSSA +++Klebsiella sp. ++Osteomyelitis (cefazolin)
  CefazolinProteus mirabilis ++Skin and soft tissue infections
Bloodstream infections, MSSA (cefazolin)
Pharyngitis
Urinary tract infections, uncomplicated
 Second generationStreptococci ++Haemophilus influenzae ++Intra-abdominal infections
  CefoxitinMSSA ++Moraxella catarrhalis ++Pneumonia, community-acquired (cefuroxime)
  CefotetanProteus sp. ++Skin/skin structure infections
  CefuroximeEscherichia coli ++Urinary tract infections
Klebsiella sp. ++ Pharyngitis
Bacteroides fragilis ++(cefoxitin, cefotetan)
 Third generationStreptococci +++Haemophilus influenzae +++Intra-abdominal infections (with metronidazole)
  CefdinirMSSA ++Proteus sp. +++Gonorrhea (cefotaxime)
  CefotaximeEscherichia coli +++Pneumonia, community-acquired
  CeftriaxoneKlebsiella sp. +++Spontaneous bacterial peritonitis
Serratia sp. +++Urinary tract infections
Citrobacter +Pyelonephritis
Enterobacter +Meningitis
Antipseudomonal cephalosporinsSee third generation, plusFebrile neutropenia (cefepime)
 CefepimeMSSA +++Enterobacter ++ (cefepime, ceftazidime/avibactam)Intra-abdominal infections (with metronidazole)
 CeftazidimeNote: ceftazidime, ceftazidime/avibactam and ceftolozane/tazobactam have poor coverage of Gram-positive organismsPseudomonas aeruginosa ++Pneumonia, hospital-acquired or ventilator-associated
 Ceftazidime/avibactamUrinary tract infections
 Ceftolozane/tazobactamOsteomyelitis
Infections by ESBL/KPC-producing Enterobacteriaceae (ceftazidime/tazobactam)
Anti-MRSA cephalosporinsSee third generation, plusPneumonia, community-acquired
 CeftarolineMSSA/MRSA +++Skin/skin structure infections
CarbapenemsStreptococci +++Haemophilus influenzae +++Intra-abdominal infections
 Imipenem-cilastatinMSSA +++Proteus sp. +++Febrile neutropenia (except ertapenem)
 MeropenemEnterococcus faecalis (imipenem) ++Escherichia coli +++Pneumonia, hospital-acquired or ventilator-associated (except ertapenem)
 DoripenemESBL Escherichia coli +++ Skin/skin structure infections, necrotizing (broad-spectrum coverage, except ertapenem)
 ErtapenemKlebsiella sp. +++Urinary tract infections
ESBL Klebsiella sp. +++Osteomyelitis
Serratia sp. +++
Enterobacter sp. +++
Bacteroides fragilis +++
Pseudomonas aeruginosa ++(except ertapenem)
Acinetobacter sp. ++(except ertapenem)
  • +++, excellent activity; ++, good activity; +, some activity; MSSA, methicillin-susceptible Staphylococcus aureus; ESBL, extended spectrum β-lactamases; KPC, Klebsiella pneumoniae carbapenemase; MRSA, methicillin-resistant Staphylococcus aureus.