Isolates from patients with Clostridium difficile infection (CDI) usually produce both toxin A (TcdA) and toxin B (TcdB), but an increasing number of reports from Europe and Asia mention infections with TcdA-negative, TcdB-positive (A-/B+) strains, usually characterized as PCR ribotype 017 (type 017). Incidence rates of CDI per 10 000 admissions in a 200-bed Argentinean general hospital were 37, 84, 67, 43, 48 and 42 for the years 2000 to 2005, respectively. The annual percentages of type 017 CDI were 7.7%, 64.6%, 91.4%, 92.0%, 75.0% and 86.4%, respectively. Comparison of 112 017-CDI patients with 41 non-017-CDI patients revealed that 017-CDI patients were more often male (68.8% vs. 46.3%; odds ratio 2.55, 95% confidence interval 1.23-5.50). All type 017 strains tested belonged to toxinotype VIII and had a 1.8-kb deletion in tcdA. In addition, 90% of tested type 017 isolates had high-level resistance to clindamycin and erythromycin, determined by the presence of the ermB gene. Multiple-locus variable-number tandem-repeat analysis (MLVA) was applied to 56 Argentinean isolates and 15 isolates from seven other countries. Country-specific clonal complexes were found in each country. Among 56 Argentinean isolates, four clonal complexes were recognized, accounting for 61% of all isolates. These clonal complexes did not show correlation over time, but seemed to be restricted to specific wards, mainly internal medicine and pulmonology wards. A total of 56% of recurrent infections were caused by a different isolate, despite identification of an identical PCR-ribotype. We conclude that C. difficile type 017 gradually replaced other circulating PCR ribotypes and that MLVA provides detailed insight into nosocomial spread.

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Bacteremia due to CASE REPORTAn 83-year-old woman was admitted because of fever and chills. She had a history of type II diabetes and hypertension. Three months before, the patient had undergone a total hip replacement. At the time of admission to the hospital she was febrile, with mild dehydration, and she appeared chronically ill with multiple decubitus ulcers (grade IV in the sacral region and grade II in the lower extremities).Laboratory tests disclosed the following values: hematocrit, 26%; white blood cell count, 22,300 (70% neutrophils); glucose, 131 mg %; Na ϩ , 122 meq/ml; K ϩ , 3 meq/ml; Cl Ϫ , 96 meq/ml. Urinalysis indicated 50 leukocytes/field. A chest radiograph was normal.On the first day, blood (aerobic and anaerobic bottles; Bact Alert), urine, and soft-tissue cultures were performed, and a combination therapy with intravenous (i.v.) ceftriaxone, 1 g three times a day (t.i.d.), and i.v. metronidazole, 0.5 g t.i.d., was empirically administered.Debridment of the sacral decubitus scar was performed. The patient's fever resolved promptly with this regimen. Blood cultures yielded an anaerobic gram-negative rod that was identified as Fusobacterium varium (anaerobic bottle; Bact Alert) in combination with Bacteroides fragilis (anaerobic and aerobic bottles; Bact Alert). The specimen obtained from the sacral decubitus ulcer yielded Fusobacterium varium, Bacteroides fragilis, Porphyromonas endodontalis, a non-spore-forming gram-positive rod, Enterococcus faecalis, and Escherichia coli. Urine culture showed growth of Escherichia coli and Enterococcus faecalis. The antibiotic regimen was changed to ampicillin-sulbactam (1.5 g/8 h) and ciprofloxacin (200 mg/12 h). New blood culture showed no growth.Five days later the patient became febrile and severe sepsis developed. Previous cultures were repeated, and the antibiotic treatment was changed to imipenem, vancomycin, and amikacin. Blood cultures, as well as the central venous catheter, were positive for methicillin-resistant Staphylococcus aureus. The patient died on day 34 of admission secondary to multiorgan failure.Bacteriology. The initial decubitus ulcer specimen and blood were plated directly onto laked-blood brucella agar and phenylethanol agar supplemented with vitamin K 1 -hemin and incubated at 35°C in an anaerobic environment. They were also plated on Levine eosin-methylene blue agar and incubated at 35°C in an oxygen atmosphere and on 5% blood agar and