Rationale:

• The most common bacteria isolated in human bite wounds are Staphylococcus aureus and epidermidis, both α- and β-hemolytic Streptococcus, Eikenella corrodens, Corynebacterium, Haemophilus influenzae, and various anaerobes, which are all susceptible to amoxicillin-clavulanate or ampicillin-sulbactam.
• Broad-spectrum antibiotics are essential in empiric therapy of infected human bite wounds because most infected human bite wounds are polymicrobial.
• There is a high incidence of β-lactamase production in anaerobes isolated from human bite wounds.
• Eikenella corrodens, which is isolated in up to 29% of human bite infections, is resistant in vitro to antistaphylococcal penicillins, first generation cephalosporins, clindamycin, aminoglycosides, and erythromycin.
• Eikenella corrodens is most sensitive in vitro to fluoroquinolones, co-trimoxazole, and amoxicillin-clavulanate.
• Newer generation fluoroquinolones (levofloxacin, moxifloxacin, gatifloxacin) have expanded anaerobic coverage in addition to being effective against Streptococcus, Staphylococcus, and Eikenella corrodens.

Evidence:

• The average number of bacteria isolated per human bite infection is five, three of which are anaerobes. It is estimated that 41% to 45% of Bacteroides fragilis isolated from human bite wound infections produce β-lactamase, according to a review article (4).
• Treatment recommendations are based on in vitro susceptibility patterns and minimum inhibitory concentrations of antibiotics obtained from multiple review articles because in vivo studies are not available (3; 4; 12).

Comments:

• None.