One-day prevalence of asymptomatic carriage of toxigenic and non-toxigenic Clostridioides difficile in 10 French hospitals.

BACKGROUND: Asymptomatic faecal carriage of Clostridioides difficile has been widely evaluated, but its prevalence across a wide range of clinical departments and related risk factors are not well described. The objectives of the PORTADIFF study were to evaluate the prevalence and identifying risk factors leading to asymptomatic carriage of both toxigenic and non-toxigenic C. difficile. METHODS: The PORTADIFF study was a 1-day prevalence study carried out in 10 different French hospitals. Adult patients, who agreed to participate, were included in this study and provided a fresh stool sample. C. difficile strains isolated from carriage were characterized by polymerase chain reaction (PCR) detection of tcdA, tcdB, cdtA and cdtB, and PCR ribotyping. RESULTS: In total, 721 patients were included in this study. The median age was 73 years (range 18-101 years) and the male/female ratio was 1.06. C. difficile (either toxigenic or non-toxigenic strains) was isolated from 79 (11%) patients; 42 (5.8%) strains were toxigenic. The prevalence rates of asymptomatic carriage ranged from 5% on surgical wards to 19% on long-term care wards. The main risk factors associated with asymptomatic carriage were antibiotic treatment within the preceding 3 months (81.8% vs 53.7%; P<0.01), hospitalization within the preceding 2 months (55.8% vs 33%; P<0.01), cumulative duration of hospital stay before study inclusion (mean 50.1 vs 34.5 days; P<0.047), and hospitalization on a ward with high global incidence of C. difficile infection. CONCLUSION: Eleven percent of hospitalized patients were asymptomatic carriers of toxigenic or non-toxigenic C. difficile, and may constitute a potential reservoir of C. difficile strains.

Amoxicillin-tolerant Pasteurella multocida strain isolated from chronic dermohypodermitis after suboptimal exposure to amoxicillin is not associated with reduced growth rate.

Pasteurella multocida is rarely observed in human chronic infections. A Pasteurella multocida strain was isolated from a skin biopsy of chronic dermohypodermitis in a 21-year-old woman without an immunocompromised state. As this strain was viable one month after a cat scratch despite treatment by amoxicillin-clavulanic acid, we compared this strain's growth rate, amoxicillin Minimal Inhibitory and Bactericidal Concentrations (MIC and MBC), resistance to serum and ability to activate neutrophil granulocytes with those of control strains isolated during acute infections in humans without previous antibiotics exposure. This particular strain was not more resistant to serum and did not induce a lower phagocytic activity than control strains. It did not grow more slowly than control strains even after suboptimal exposure to amoxicillin. This particular strain was tolerant to amoxicillin but tolerance did not appear sufficient alone for the induction of a chronic infection in a host without an immunocompromised state.

Carriage of ESBL-producing Enterobacteriaceae in French hospitals: the PORTABLSE study.

BACKGROUND: Currently, contact precautions are recommended for patients colonized or infected with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Recent studies have challenged this strategy. This study aimed to assess the rate of ESBL-PE faecal carriage among hospitalized patients according to type of hospital ward, and to identify risk factors associated with carriage. METHODS: A point prevalence study was conducted in five different types of hospital ward [medical, surgical, intensive care unit (ICU), after care and rehabilitation, and geriatric] in eight French hospitals. All patients included in the study provided a fresh stool sample. RESULTS: In total, 554 patients were included in the study, with a median age of 73 years (range 60-82 years). The overall faecal carriage rate of ESBL-PE was 17.7%. The most frequently encountered species among ESBL-PE was Escherichia coli (71.4%), followed by Klebsiella pneumoniae (14.3%). Risk factors associated with ESBL-PE faecal carriage on univariate analysis were: living in the Paris region (P<0.01) and hospitalization on a geriatric ward (P<0.01). Interestingly, the cumulative duration of hospital stay before screening was not associated with a significantly higher prevalence of ESBL-PE carriage, regardless of ward type. The ESBL-PE colonization rate was much higher for patients hospitalized on geriatric wards (28.1%) and ICUs (21.7%) compared with those for patients hospitalized on surgical wards (14.8%), medical wards (12.8%) or aftercare and rehabilitation (11.2%). CONCLUSION: The overall prevalence of ESBL-PE faecal carriage was 17.7%, with only 21% of patients identified previously as carriers. The delay between admission and screening was not associated with an increase in ESBL-PE faecal carriage.

Characterization of quinolone resistance mechanisms in Enterobacteriaceae recovered from diseased companion animals in Europe.

ComPath is a European monitoring programme dedicated to the collection of bacterial pathogens from diseased dogs and cats to determine their antibiotic susceptibility. The objective was to characterize genetic determinants associated with quinolone resistance among 69 enrofloxacin non-wild type strains selected among 604 non-duplicate Enterobacteriaceae isolates collected in 10EU countries from 2008 to 2010: quinolone resistance determining region (QRDR) and plasmid-mediated quinolone resistance (PMQR). Among them, 17% (12/69) carried at least one PMQR (9/12 qnrB, qnrS or qnrD and 4/12 aac(6')-Ib-cr) and 83% (57/69) no PMQR. All the Klebsiella pneumoniae isolates chromosomally carried oqxAB . No qepA genes were detected. Eight strains did not carry any mutations in QRDR (4 PMQR-positive and 4 PMQR-negative strains). From the 12 PMQR-positive strains, 4 showed enrofloxacin MICs≤2µg/mL, and 8 MICs≥8µg/mL (resistant). These latter strains carried 1-5 mutations in QRDR, including a ParE I529L mutation. qnrD was found in 2 Proteus mirabilis and the plasmids were similar to pDIJ09-518a previously described. For the 57 non-PMQR strains, 29 strains showed MICs≤2µg/mL (4 with no QRDR mutations, 21 with 1 mutation in GyrA, 4 with 2 mutations in GyrA) and 28 showed enrofloxacin MICs≥8µg/mL carrying at least 2 mutations in QRDR, including a ParE I529L mutation for 2 Escherichia coli strains with a total of 5 QRDR mutations. No GyrB mutations were found. qnr was the major PMQR and qnrD was only detected in Proteus spp. Twelve strains carried at least 4 mutations.