Toxins A and B are known to be the primary virulence factors of Clostridium difficile. Other potential virulence factors have been identified such as binary toxin (actin-specific ADP-ribosyltransferase toxin, or CDT). A retrospective case-control study was performed in order to identify clinical features and risk factors of C. difficile-associated diarrhoea due to binary toxin-producing strains. Each case (a patient with diarrhoea due to binary toxin-producing strain) was compared with two controls (patients with diarrhoea due to a C. difficile strain that did not produce binary toxin) matched for ward and date of hospitalization. cdtA and cdtB genes were screened by PCR. Production of CDT was studied by Western blotting using an antiserum against Ia and Ib from the Clostridium perfringens iota toxin, and the activity of the binary toxin was assessed using an ADPribosyltransferase assay. Twenty-six cases (14 males and 12 females) were identified in 1999 and 2000. Cases and controls did not differ significantly for sex, age, previous administration of antibiotics or frequency of endoscopic examination. Diarrhoea was community-acquired more often in cases than in controls (65 . 4 vs 35 . 7 %, P ¼ 0 . 017) and more often represented the cause of hospitalization (61 . 5 vs 26 . 2 %, P ¼ 0 . 003). Moreover, diarrhoea in cases was more frequently associated with abdominal pain (63 . 6 vs 39 . 4 %, P ¼ 0 . 07) and with liquid stools (76 . 9 vs 59 . 5 %, P ¼ 0 . 14) than in controls. These results suggest that there could be a correlation between the production of binary toxin and the severity of diarrhoea.

Three types of multidrug-resistant Escherichia coli isolates, called GEN S, GEN R, and AMG S, according to their three different aminoglycoside resistance patterns, were responsible for urinary tract colonization or infection in 87, 12, and 13 new patients, respectively, in a French 650-bed geriatric hospital over a 13-month period. The three E. coli types belonged to the same clone and phylogenetic group (group B2) and had identical transferable plasmid contents (a 120-kb plasmid), ␤-lactam and fluoroquinolone resistance genotypes (bla TEM-1B , bla CTX-M-15 , and double mutations in both the gyrA and the parC genes), and virulence factor genotypes (aer, fyuA, and irp2). They disseminated in the geriatric hospital, where the antibiotics prescribed most often were fluoroquinolones and ceftriaxone, but not in the affiliated acute-care hospital, where isolation precautions were applied to the transferred patients. Thus, E. coli isolates, both CTX-M-type ␤-lactamase producers and fluoroquinolone-resistant isolates, might present a new challenge for French health care settings.For the last 10 years, sporadically but regularly, the microbiology literature has reported on multidrug-resistant (MDR) bacteria in geriatric hospitals, long-term-care facilities, and nursing homes (14,26,30,44). The emergence of these bacteria in such health care facilities has become a public health concern because implementation of isolation precautions, which is the principal measure recommended in acute-care hospitals to avoid cross-transmission (12), is often considered deleterious for the quality of life of elderly people living in long-term-care facilities. Moreover, the elderly patients carrying MDR bacteria represent a reservoir of these bacteria in acute-care hospitals when they are transferred to them. The very least that can be done to address this double concern is to survey long-term-care facilities for the emergence and incidence of MDR bacteria and to inform clinicians in acute-care hospitals of the real or potential existence of these isolates in patients transferred from long-term-care facilities. Such a twofold approach, observation and an infection control program, is certainly more easily managed when the same microbiological department, as in Hôpital A. Paré, is in charge of the patients in both types of care settings.This article reports on molecular analyses performed with three types of MDR Escherichia coli isolates which successively emerged and spread in the 650-bed geriatric hospital which is affiliated with a 450-bed acute-care hospital, Hôpital A. Paré.It also describes the particular hygiene measures which were successfully established in the acute-care hospital to avoid secondary cases of MDR E. coli colonization or infection from the patients transferred from the geriatric hospital. MATERIALS AND METHODSPopulation and collection of bacteria. From October 2001 to October 2002, each first isolate of the family Enterobacteriaceae displaying an extended-spectrum ␤-lactamase (ESBL) production phenotype according to...

Commercial chemiluminescent DNA probes (Accuprobe; Gen-Probe, San Diego, Calif.) for the identification ofMycobacterium tuberculosis (MTB) complex, M. avium complex (MAC), M. gordonae, and M. kansasii were evaluated with 134 clinical isolates. These included 36 MTB complex, 40 MAC, 27 M. gordonae, 9 M. kansasii, and 22 Mycobacterium spp. The specificity was 100% for the four probes. The sensitivity was 100o for the MTB complex and M. gordonae probes and 95.2% for the MAC probe. Five of the nine M. kansasii isolates tested were not detected with the probe.

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The incidence and transmission patterns of extended-spectrum-␤-lactamase (ESBL)-producing Klebsiella pneumoniae in patients admitted to the intensive care unit (ICU) of a university hospital were investigated over a 3-year period. K. pneumoniae isolates were characterized by antibiotic susceptibility, capsular serotyping, plasmid profiles, and pulsed-field gel electrophoresis (PFGE) of genome macrorestriction patterns with XbaI, and the results were compared with those obtained by typing with the randomly amplified polymorphic DNA (RAPD) patterns. The discriminatory power of RAPD typing was evaluated for three primers. The incidence of isolation of ESBL-producing K. pneumoniae was 2.5 cases per 1,000 admissions to the ICU versus 0.35 cases per 1,000 admissions to other units (relative risk, 7.03; 95% confidence interval, 3.89 to 12.69). Infection developed in 53% of evaluable patients. Thirty-six percent of the cases were possibly acquired in other institutions. Isolates from ICU patients were subdivided into six capsular serotypes and into four clonal groups based on antibiotype, plasmid content, and PFGE and RAPD patterns. Two clones were associated with clusters of cross-infection, involving 5 and 12 patients, respectively. Following implementation of contact isolation precautions, the incidence of nosocomial acquisition of ESBL-producing K. pneumoniae decreased from 0.55 to 0.26 cases per 1,000 admissions (P ‫؍‬ 0.03). PFGE and RAPD analysis showed concordant results and comparable discrimination for differentiation between groups of epidemiologically related strains of ESBLproducing K. pneumoniae. More subclonal variants were determined among epidemic clones by PFGE analysis than by RAPD analysis. Both methods are useful for typing K. pneumoniae strains in epidemiological investigations, although RAPD analysis is more efficient.