Human Bites

Staphylococcus aureus was the most frequent organism isolated, in studies that did not employ anaerobic methodology (29). Penicillin-resistant gram-negative rods alone or in mixed culture have been reported in 24% to 43% of bite wounds cultured (29,30).

Studies that employed anaerobic methodologies reported the recovery of anaerobic bacteria in human bites in adults (31) and children (32). Goldstein et al. (31) recovered anaerobic bacteria in over half of human bite wounds and clenched-fist injuries. The predominant isolates were anaerobic gram-negative bacilli (AGNB) (including pigmented Prevotella and Porphy-romonas spp., and Bacteroides spp.), Fusobacterium nucleatum, and anaerobic gram-positive cocci. The predominant aerobes recovered were S. aureus, group A beta-hemolytic streptococci (GABHS), and E. corrodens.

Talan et al. (2) conducted a multicenter prospective study of 50 patients with infected human bites. Fifty-six percent of injuries were clenched-fist injuries and 44% were occlusional bites. The median number of isolates per wound culture was 4 (3 aerobes and 1 anaerobe); aerobes and anaerobes were isolated from 54% of wounds, aerobes alone were isolated from 44%, and anaerobes alone were isolated from 2%. Isolates included Streptococcus anginosus (52%), S. aureus (30%), E. corrodens (30%), F. nucleatum (32%), and Prevotella melaninogenica (22%). Candida spp. were found in 8%. Fusobacterium, Peptostreptococcus, and Candida spp. were isolated more frequently from occlusional bites than from clenched-fist injuries. Many strains of Prevotella and S. aureus were beta-lactamase producers.

Brook (32) recovered anaerobes in 90% of 18 children with human bites (Table 1). A total of 97 isolates (range, 1-8/specimen) were recovered (5.4/specimen): 44 aerobes (2.4/specimen) and 53 anaerobes (3.0/specimen). Beta-lactamase activity was noted in 13 isolates that were recovered from 11 patients. The majority of these were nine isolates of S. aureus, two of the six pigmented Prevotella and Porphynomonas spp., one of the three Prevotella oralis, and the single isolate of Bacteroides ovatus.

The results of these studies show the normal oral flora, rather than the skin flora, to be the source of most bacteria isolated from human bite wound cultures.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

Get My Free Ebook

Post a comment