Soft tissue infection caused by Kluyvera species.

To the Editors: Kluyvera species are described infrequently in association with clinically significant infections, and infections caused by these Gram negative rods are especially rare in immunocompetent children. Most of the recently reported infections caused by Kluyvera species involved bacteremia, peritonitis, soft tissue infections and infections of the urinary and gastrointestinal tracts. We report a 15-year-old previously healthy young man who was hospitalized in November 2003 with an infected wound on his left foot. Three days before admission he sustained a puncture wound through his rubber slippers and through the plantar and dorsal surfaces of his left foot when he stepped on a dirty metal rake in his backyard. The rake had been left outdoors and was used in yard work and to clean up dog feces. He was evaluated at a community clinic after the injury and given cephalexin therapy. He was admitted after 2 days of cephalexin therapy when his wound became tender, swollen and erythematous. Radiographs revealed diffuse swelling with air within the soft tissues along the dorsal aspect of the left foot along with a small foreign body at the fifth metatarsophalangeal joint. A computerized tomographic scan confirmed the presence of air in the soft tissues and presence of 2 foreign bodies in the foot. Two small rocks were surgically removed from the dorsum of foot along with drainage of a small abscess located between the fourth and fifth metatarsals. The aerobic cultures obtained from the purulent material grew Kluyvera species along with Enterococcus species after 4 days of incubation. Anaerobic cultures had no growth. Antimicrobial susceptibility testing of the Kluyvera isolate showed resistance to ampicillin but susceptibility to broad spectrum cephalosporins, aminoglycosides, trimethoprim-sulfamethaxazole, fluroquinolones and carbapenems. The patient received 5 days of parenteral penicillin, clindamycin and ceftriaxene treatment while culture results were pending. The treatment was later changed to oral ciprofloxacin and the patient was discharged home to finish a 10 day course of ciprofloxacin. He was followed for 2 months after discharge and had no further problems. Kluyvera is a relatively new species of the family Enterobacteriaceae. It is a motile, Gram negative rod that is oxidase and catalase positive, a nitrate reducer and a lactose fermenter with production of gas and acid. Kluyvera is present in soil, water, sewage, hospital environments and food products of animal origin. The soil contaminated wound in our patient explains the entry site of this bacterium. While the presence of air in our patient may be a result of the introduction of foreign bodies, the gas production by the bacterium may be another explanation and has been described previously. Kluyvera isolates are usually resistant to ampicillin but susceptible to aminoglycosides, third-generation cephalosporins, quinolones, and trimethoprim/ sulfamethoxazole. The host conditions associated with these uncommon infections are poorly defined. In addition to the reports of infections in immunocompromised patients, Kluyvera infections at various sites, ranging in severity have been described in patients without identifiable underlying medical conditions. Although there have been previous case reports of soft tissue infections with this particular organism, to our knowledge, this is the first case of a soft tissue infection reported in the pediatric population. Only 8 pediatric cases of Kluyvera infections have been previously reported in the English language medical literature. Two of these children had no underlying disease. Severe infections in immunocompetent patients, like in our patient, show that Kluyvera species may have a more pathogenic nature than previously believed.