Background: The number of patients with yeast infection has increased during the last years. Also the variety of species of clinical importance has increased. Correct species identification is often important for efficient therapy, but is currently mostly based on phenotypic features and is sometimes time-consuming and depends largely on the expertise of technicians. Therefore, we evaluated the feasibility of PCR-based amplification of the internally transcribed spacer region 2 (ITS2), followed by fragment size analysis on the ABI Prism 310 for the identification of clinically important yeasts.

A gram-negative alkaline phosphatase-and pyrrolidone peptidase-positive rod-shaped bacterium (CCUG 45702) was isolated from two aerobic blood cultures from a female cancer patient. No identification could be reached using phenotypic techniques. Amplification of the tRNA intergenic spacers revealed fragments with lengths of 116, 133, and 270 bp, but no such pattern was present in our reference library. Sequencing of the 16S rRNA gene revealed its identity as Moraxella atlantae, a species isolated only rarely and published only once as causing infection. In retrospect, the phenotypic characteristics fit the identification as M. atlantae (formerly known as CDC group M-3). Comparative 16S rRNA sequence analysis indicates that M. atlantae, M. lincolnii, and M. osloensis might constitute three separate genera within the Moraxellaceae. After treatment with amoxicillin-clavulanic acid for 2 days, fever subsided and the patient was dismissed. CASE REPORTIn April 2001 a 31-year-old female patient was admitted to the oncology department with a history of intermittent fever for more than 1 week and with complaints of right hypochondrial pain and rectal cramps. The patient had a rectal adenocarcinoma that was diagnosed 1 year previously, with recent massive liver metastasis which had been treated with an anterior resection and with palliative chemotherapy (irinotecan and 5-fluorouracil) for 10 months. Clinical examination revealed a relapse of the rectal cancer at the anastomosis and a hepatomegaly of 8 cm. X-ray examination of the thorax revealed no infiltrates. Three pairs of blood cultures and a urine culture were carried out, with the latter being negative. Streptococci of the viridans group were isolated from one aerobically incubated culture bottle. A gram-negative rod, susceptible to all antibiotics tested and later identified as Moraxella atlantae (CCUG 45702), was isolated from the two other aerobic bottles. The anaerobic cultures remained negative. The patient was treated with amoxicillin-clavulanic acid (875 mg) two times a day, resulting in the disappearance of the fever after 2 days, whereafter the patient was dismissed. A computed tomography of the abdomen 7 days later showed an abscess around the rectum, which was drained with evacuation of 100 ml of serous fluid. Culture of this fluid remained negative. The patient died 4 months later as a result of her underlying disease.The blood culture bottles (FA aerobic and SN anaerobic bottles; Organon Teknika, Boxtel, The Netherlands) were inoculated with 10 ml of blood and incubated in the Bact/Alert 3D system (Organon Teknika). Gram staining showed short, plump, rod-shaped to coccoid gram-negative rods. On tryptic soy agar plus 5% sheep blood (Becton Dickinson, Erembodegem, Belgium), colonies were small and grayish, with twitching motility and corroding activity. The isolate grew well on MacConkey agar, in contrast to most other Moraxella sp. It was nonmotile. Catalase and oxidase were positive. No sugars were acidified, either fermentatively or oxidatively. No grow...

Background: Enterobacter aerogenes and Klebsiella pneumoniae are common isolates in clinical microbiology and important as producers of extended spectrum β-lactamases (ESBL). The discrimination between both species, which is routinely based on biochemical characteristics, is generally accepted to be straightforward. Here we report that genotypically unrelated strains of E. aerogenes can be misidentified as K. pneumoniae by routine laboratories using standard biochemical identification and using identification automates.