Mycobacterium fortuitum Infection after a Brown Bear Bite

Abstract

A 56-year-old male was admitted to the hospital after a bear attack. A wounded brown bear (Ursus arctos) had attacked the patient. The patient had several bite wounds. The most serious wound was a deep penetrating bite wound in his left thigh. This wound needed immediate debridement, and ceftriaxone prophylaxis was commenced. The wound penetrated the fascial planes. All necrotic tissues and foreign material were surgically removed, and the wound was left open. The patient's wounds required redebridements on the 7th and 12th days after the patient was admitted to the hospital due to necrotic residual tissue and a hematoma. After the first operation, he received 4 g of piperacillin-tazobactam three times a day, which was subsequently changed to amoxicillin-clavunate (875 mg of amoxicillin and 125 mg of clavunate) twice a day (b.i.d.). Bacterial specimens were collected in all of the operations and cultured.Direct examination of the specimen revealed leukocytes, but no bacteria. Cultures of bacteria from the deep wound in the thigh grew Streptococcus sanguis (identified by using RapID 32 Strep; bioMérieux, Marcy l'Etoile, France), Neisseria sicca (identified by RapID NH system; Remel, Inc., Lenexa, Kans.), and Bacillus spp. After 7 days of incubation, cultures on chocolate plate agar grew rough, white colonies. Gram staining revealed acid-fast gram-positive rods. The bacterium was identified as Mycobacterium fortuitum by PCR (GenoType Mycobacterium; Hain Lifescience GmbH, Nehren, Germany). The strain was in vitro multiply resistant. It was not susceptible to all cephalosporins, pyrazinamide, streptomycin, trimethoprimsulfamethoxazole, rifabutin, and tetracyclines tested. The strain was susceptible to clarithromycin (MIC of 0.25 g/ml), ciprofloxacin, levofloxacin, amikacin, tobramycin, meropenem, and vancomycin.The patient was treated with clarithomycin (500 mg b.i.d.) and ciprofloxacin (500 mg b.i.d.) orally once the culture results were available. The wound was covered with autologous split thin skin grafts. The bacterial sample taken before the application of skin grafts was still M. fortuitum. The patient tolerated the medication well with no major adverse events. The wound in the thigh healed within 2 months. Medication was continued for 6 months.The bacteriology of a grizzly bear bite was recently published (3). The cultures grew Serratia fonticola, Serratia marcescens, Aeromonas hydrophila, Bacillus cereus, and Enterococcus durans but no anaerobes and no atypical mycobacteria. Atypical mycobacterial infections after animal bites are probably rare.M. fortuitum is an atypical mycobacterium. It is classified as a rapid-growing mycobacteria (Runyon group IV). It has been found in sewage and also in natural waters (1). Atypical mycobacteria are environmental bacteria that rarely cause infections in immunocompetent hosts. Clinical infections, mostly skin and soft tissue infections, have been reported after surgery or trauma, particularly after cardiothoracic surgery (2). To our knowledge, this is the first report o...

Large carnivore attacks on hominins during the Pleistocene: a forensic approach with a Neanderthal example

“…Carnivore attacks are characterized by the combined occurrence of injuries (including puncture wounds, lacerations, avulsions, and bone fractures (Baliga et al 2012)), crushing, and penetrating trauma (Agarwal et al 2011). Humans attacked by large carnivores are consequently at risk of suffering blunt and penetrating trauma caused by teeth, paws, and claws, which may lead to a local infection (Capitini et al 2002;Kunimoto et al 2004;Lehtinen et al 2005;Türkmen et al 2012) because wounds are often contaminated with a variety of pathogens (polymicrobial infection) such as Pasturella multocida and others (Kizer 1989;Isotalo et al 2000;Linnell et al 2002;Abrahamian and Goldstein 2011). Fatal attacks are common, especially in Africa and Asia (Conrad 1992), although many cases are reported in which victims survive a violent encounter with a carnivore (Agarwal et al 2011).…”

Microbiology of Animal Bite Wound Infections

“…Lehtinen et al reported a case of a 56-year-old male who sustained several bite wounds from a brown bear (Ursus arctos) (145). Bacterial cultures from a deep thigh bite wound grew Streptococcus sanguis, Neisseria sicca, Bacillus species, and Mycobacterium fortuitum.…”

“…Data for the oral bacteriology of bears as well as bear bite wounds in humans are limited to a few studies and case reports (79,140,145,175,193). Organisms isolated from grizzly or black bear oral cavities have included Streptococcus (61%), Staphylococcus (48%), Escherichia (40%), Enterobacter (25%), Citrobacter (10%), Hafnia (10%), Proteus (6%), and Acinetobacter (6%) species (175).…”

Detection of Mycobacterium avium subsp. paratuberculosis in Two Brown Bears in the Central European Carpathians

“…Most studies have involved oral bacteria of bears or bacteria associated with bear bite wounds (Parry et al, 1983;Goatcher et al, 1987;Kunimoto et al, 2004). The only reported nontuberculous mycobacterium from any bear species is M. fortuitum that was isolated from a brown bear (Ursus arctos) bite wound (Lehtinen et al, 2005).…”