We performed a 5-year retrospective study to evaluate the effect of long-term administration of norfloxacin on the epidemiology of severe hospital-acquired infections in patients with advanced cirrhosis. Sixty-seven episodes of spontaneous bacterial peritonitis and 60 episodes of bacteremia occurred in, respectively, 46 patients (group 1a) and 52 patients (group 1b) who did not receive norfloxacin, while 23 and 17 episodes occurred in 21 patients (group 2a) and 17 patients (group 2b) during or within 10 days after long-term administration of norfloxacin. Enterobacteriaceae were more prevalent in groups 1a and 1b than in the other two groups (P < .001 and P < .01, respectively); conversely, staphylococci were more prevalent in groups 2a and 2b (P < .001 and P < .05, respectively). The rate of staphylococcal resistance to methicillin was 53.6% in groups 1a and 1b and 77.3% in groups 2a and 2b. We conclude that long-term norfloxacin administration to cirrhotic patients reduces the risk of gram-negative infections but increases the risk of severe hospital-acquired staphylococcal infections and of high-level resistance to antibiotics.

We carried out quantitative culturing of stools from 31 hospitalized alcoholic patients with cirrhosis and ascites, before treatment with 400 mg of norfloxacin per day, weekly for the first month, and then every 2 weeks thereafter for 15 to 229 days (median, 54 days). Members of the family Enterobacteriaceae virtually disappeared from the stools (<102/g), but treatment had little effect on enterococci. No selection of resistant organisms occurred in 15 patients, but the remaining 16 patients developed fecal organisms resistant to fluoroquinolones between days 14 and 43 of treatment (median, 25 days). Staphylococcus aureus was isolated four times, coagulase-negative Staphylococcus spp. were isolated six times, Citrobacter freundii was isolated four times, Enterobacter cloacae was isolated three times, KlebsieUla oxytoca was isolated twice, Proteus rettgeri was isolated once, and untypeable streptococci were isolated six times. Some isolates persisted, while others were transient (one to seven consecutively positive cultures). The MICs of four quinolones (nalidixic acid, norfloxacin, ofloxacin, and ciprofloxacin) were determined by use of experimental microwell strips (ATB CMI; Biomerieux S.A.). All the strains isolated before treatment were susceptible to the four quinolones, with low MICs, whereas those isolated during norfloxacin treatment were highly resistant. Long-term norfloxacin administration thus carries a risk of disturbing the bacterial ecology in these patients, suggesting that digestive decontamination should no longer be prescribed routinely to cirrhotic patients with ascites.

Carriage of CephR strains is not associated with subsequent infection by these organisms in hospitalized cirrhotic patients. In contrast, MRSA carriage was an important risk factor for MRSA bacteremia and urinary tract infection.

No abstract

Thirty‐eight different strains of extended‐spectrum β‐lactamase (ESBL)‐producing Klebsiella pneumoniae (ESBL Kp), isolated from urine and pus samples of 38 patients hospitalized in a medium‐ and long‐stay neurology department between 1 January 1992 and 31 December 1996, were analysed by antibiotic resistance phenotyping, DNA macrorestriction by pulsed‐field electrophoresis and isoelectric focusing of β‐lactamases. An epidemiological survey was conducted to identify risk factors for infection by ESBL Kp in this setting. The 38 isolates were distributed into 13 antibiotypes, three of which predominated (13, six and six isolates). The DNA macrorestriction pattern identified 15 genotypes, four of which predominated (11, six, four and four isolates). A combination of the two typing methods revealed several epidemic clones that emerged consecutively. Two main types of ESBL (SHV‐2 and CTX‐1) were identified by isoelectric focusing, the former predominating. The case‐control study showed that the length of hospital stay, degree of malnutrition and dependency, and urinary sphincter status were the main factors significantly associated with ESBL Kp isolation.