Bite wounds human bites

I Bite-wound infections generally are polymicrobial. On average, five different bacterial species can be isolated from an infected animal bite wound.3 Both the normal flora of the biter s mouth and that of the bite recipient s skin can be implicated. The bacteriology of the cat and dog mouth is quite similar. Pasteurella multocida, a gram-negative aerobe, is one of the predominant pathogens, isolated in up to 50% of dog and 75% of cat bites. S. viridans are the most frequently cultured bacteria from human bite wounds.3,43 Table 70-10 provides a comprehensive list of cat, dog, and human bite-wound pathogens. 

Most bite wounds require antibiotic therapy only when clinical infection is present. However, prophylactic therapy is recommended for wounds at higher risk for infection. These include human bites, deep punctures, bites to the hand, and bites requiring surgical repair.43... 

The most effective agent for the treatment (and prophylaxis) of human and animal bite-wound infections is amoxicillin-clavulanate. Alternatives for patients with significant penicillin allergies include either a fluoroquinolone or TMP-SMX in combination with clindamycin. Doxycycline also may be prescribed. The durations of prophylaxis and treatment generally are 3 to 5 and 10 to 14 days, respectively.3... 

Management of bite wounds consists of aggressive irrigation and topical wound dressing, surgical debridement, and immobilization of the affected area. Primary closure for human bites is not generally recommended. Tetanus toxoid and antitoxin may be indicated. 

Goldstein EJ, et al. In vitro activity of Bay 12-8039, a new 8-methoxyquino-lone, compared to the activities of 11 other oral antimicrobial agents against 390 aerobic and anaerobic bacteria isolated from human and animal bite wound skin and soft tissue infections in humans. Antimicrob. Agents Chemother., 1997, 41, 1552-1557. 

Another bacterium that contributes to commensal biofilms is Eikenella corrodens, a gram negative, small rod (Fig. 13.2c). E. corrodens grows in a healthy oral cavity by reducing nitrate in saliva to nitrite (Sects. 1.3.2 and 12.1.3). It is an important contributor to bite wound infections and is also the major known producer of lysine decarboxylase, which converts lysine to cadaverine and carbon dioxide (Fig. 13.4). Lysine is a nutritionally essential amino acid, whereas cadaverine is not. In humans, E. corrodens and lysine... 

All bite wounds (either animal or human) should be irrigated thoroughly with large volumes of sterile normal saline, and the injured area should be immobilized and elevated. Infections developing within the first 24 hours after a dog or cat bite are caused most often by Pasteurella multocida and should be treated with penicillin or amoxicillin for 10 to 14 days. Infections developing more than 36 to 48 hours after an animal bite are most likely caused by staphylococci or streptococci and should be treated with an antistaphylococcal penicillin or cephalosporin. 

While antimicrobial prophylaxis of dog or cat bites is not recommended routinely, patients with noninfected human bite injuries of the hand should be given prophylactic antimicrobial therapy with penicillin plus dicloxacillin for 3 to 5 days. Infected wounds of the hand, particularly clenched-fist injuries, should be treated with penicillin plus dicloxacillin or amoxicillin-clavulanate for 7 to 14 days. 

Bite wounds have a substantial potential for infectious complications. If left untreated, complications such as soft tissue infection and osteomyelitis may occur, possibly requiring extensive debridement or amputation. Approximately half the population in the United States will be bitten by either an animal or another human sometime during their lifetimes. " ... 

Rest JG, Goldstein EJC. Management of human and animal bite wounds. Emerg Med Clin North Am 1985 3 117-126. 

Brooks I. Microbiology and management of human and animal bite wound infections. Primary Care Clin Office Pract 2003 30 1-11. 

H. influenzae, gonococci, and E. coli. It also is effective in the treatment of acute otitis media in children, sinusitis, animal or human bite wounds, cellulitis, and diabetic foot infections. The addition of clavulanate to ticarcillin (timentin) extends its spectrum to include aerobic gram-negative bacilli, S. aureus, and Bacteroides spp. There is no increased activity against Pseudomonas spp. 

Examples of common clinical situations in which nonsurgical antimicrobial prophylaxis is effective are given in Table 51-4. Nonsurgical prophylaxis, mentioned in earlier chapters, includes the prevention of CMV and HIV infections, influenza, meningococcal infections, and tuberculosis. Though somewhat less effective, antimicrobial prophylaxis is also commonly used for animal or human bite wounds and chronic bronchitis. Severely leukopenic patients are often given prophylactic antibiotics. 

Koiczak B, Bisgaard M, Christensen H, Kuhnert P. Freckriksenia canicola gen. nov., sp. nov. isolated from dogs and human dog-bite wounds. Antonie Van Leeuwenhoek. 2014 105(4) 731-41.doi 10.1007/sl0482-014-0129-0. 

The natural reservoirs are humans, and within the United States, flying squirrels. R. prowazekii is not transmitted by the bite of the louse, but rather by contamination of the bite, or other open wounds, by the infected feces of the louse. Lice begin releasing rick-ettsiae in their feces within 6 days after becoming infected. Lice die within 2 weeks after becoming infected. Rickettsiae may remain viable in dead lice for weeks. This is a biosafety level 3 agent. 

A bite is nearly painless, but will break the skin in most cases. The venom is not injected, but enters the wound via the saliva. The venom applied by the blue ring octopus is not produced by itself, but by bacteria inhabiting the salivary glands of the octopus. The bacteria is transferred from the mother to the young and even the eggs contain sufficient amounts of venom to be harmful. The venom has two components that can be separated by simple means. The first is most effective on crustaceans but harmless to humans. The other is similar to the toxin present in the Pufferfish and serves to as a defense against predatory animals. 

Many species of mushrooms synthesize l-octen-3-ol, which serves as a repellent that drives off predatory slugs. Such mushrooms can be recognized by small bite marks on their caps, where the slug started to nibble before the volatile compound was released. Humans are not put off by the smell because, to them, l-octen-3-ol smells like a mushroom. l-Octen-3-ol also has antibacterial properties that may protect the mushroom from organisms that attempt to invade the wound made by the slug. Not surprisingly, the species of mushroom that banana slugs commonly eat cannot synthesize l-octen-3-ol. 

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