The Kluyvera species were described in 1936 by Kluyver and van Niel. However, they were molecularly characterized by Farmer, in 1981. The genus contains 4 species: Kluyveracryocrescens, Kluyveraascorbata, Kluyvera georgiana, and Kluyveracochleae. The latter, has not been detected in humans.

This enterobacteria is a free-living organism, found in water, soil, sewers, hospital sinks, and animal-derived products. In human beings, it is part of the normal intestinal flora, but in small amounts. Most often, this pathogen behaves as a commensal organism, however, it can rarely lead to sickness, and also behaves as an opportunistic pathogen. It is unknown if the infections caused by this germ are endogenous versus acquired from the environment, or if both ways are equally important.

The Kluyvera species belong to the Enterobacteriaceae family, with Gram-negative bacilli that have peritrichous flagella, which allows them to move, catalase-positive and oxidase-negative, which grow in McConkey agar, they can ferment glucose, they are indole-positive, methyl redpositive; Vogues Proskauer-negative, citrate-positive, H2Snegative, urease-negative, phenylalanine deaminasenegative, and arginine dihydrolase-negative, lysine-positive, and ornithine decarboxylase-positive. The colonies are similar to E. Coli, however, they are drier and rougher.

The sites of infections vary. They include peritoneal fluid, urine, and skin, even bacteremia. As of now, there isn’t a specific clinical pattern of infections by this bacteria.

Case description

73 year old male, works in automotive repair, diabetic for over 20 years, has hypertension, dyslipidemia, ischemic cardiomyopathy for the post transurethral resection 7 years prior.

His last hospital admission was 11 months ago, secondary to an ischemic cerebrovascular accident due to atherothrombosis, which left a partial hemiparesis of left upper extremity and a Rankin 2. There is no history of smoking, alcohol intake or drug addiction.

The patient was admitted to the Emergency Room with a one month history of an infectious process of his 4th and 5th toes of the right foot. Empiric treatment with oxacillin and clindamycin was initiated , without response, and a systemic inflammatory response and fever persisted. He also was found to have severe arterial insufficiency involving the distal circulation of the right lower extremity, for which a below-the-knee amputation was recommended. After surgery, the systemic inflammation resolved, therefore oxacillin and clindamycin were stopped.

Several days after surgery, the patient remained oxygen dependent; bilateral reticulonodular lung infiltrates were documented on the chest x-ray and an increase in C-reactive protein (CRP) at 149 ng/ml, and for this reason empiric treatment with third generation cephalosporins (Cefotaxime) was started, and both blood and urine cultures were obtained.

Both sets of blood cultures grew a gram-negative bacillus at 10.3 and 13.7 hours. Subsequently it was identified in VYTEK2 system as Kluyvera cryocrescens, which was corroborated as Kluyvera sp by analytical profile index. By that moment the antibiotic sensitivity testing was available and showed it was sensitive to cefotaxime (Table 1).

Table 1: Antibiotic sensitivity pro_le of Kluyvera cryocrescens isolated in the case 

10 days of antibiotic treatment were completed with Cefotaxime, with a significant clinical improvement with a reduced requirement in oxygen supplementation and a significant decrease in the CRP.