Genetic context of plasmid-carried blaCMY-2-like genes in Enterobacteriaceae.

Analysis of 15 European clinical Enterobacteriaceae isolates showed that differences in the genetic context of blaCMY-2-like genes reflected the replicon type, usually IncA/C or IncI1. These blaCMY-2 loci may originate from the same ISEcp1-mediated mobilization from the Citrobacter freundii chromosome as structures described in earlier studies.

Estimation of methicillin-resistant Staphylococcus aureus transmission by considering colonization pressure at the time of hospital admission.

Our objective was to evaluate the accuracy of a methicillin-resistant Staphylococcus aureus (MRSA) rate using the imported MRSA reservoir identified at the time of hospital admission. Two indicators were used: the number of imported MRSA patient-days/total number of patient-days [representing colonization pressure (CP) at the time of admission] and the incidence of hospital-acquired MRSA isolated from clinical samples expressed as density/100 patient-days for carriers identified at the time of admission [representing the incidence taking CP into account (ICP)]. The variations of these indicators were analysed and compared with two more common indicators: percentage of MRSA acquired in our hospital and the incidence of hospital-acquired MRSA isolated from clinical samples expressed as density/1000 patient-days within three four-month periods during 2002. Common indicators varied similarly, with marked decline during the third period; first-period CP was twice that of other periods (P<10(-6)) and the highest (>two-fold) ICP was seen in the summer (second) period (P<0.001) when the personnel/patient ratio was the lowest. Thus, comparison of different indicators within four-month periods underlines important differences between common and novel indicators. Despite several limitations, ICP should be helpful in the interpretation of MRSA surveillance data, particularly for estimating the extent of MRSA transmission.

Impact of screening for MRSA carriers at hospital admission on risk-adjusted indicators according to the imported MRSA colonization pressure.

We evaluated the impact of the different components of a screening programme of methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission on the value of two risk-adjusted rates: the proportion of imported MRSA and an indicator of the MRSA colonization pressure (ICP), and the incidence of MRSA acquired and detected in our hospital. Indicators were calculated: (1) with no screening programme; (2) with a programme limited to the intensive care unit (ICU); (3) with a programme extended to patients with risk factors for MRSA carriage hospitalized in non-ICU wards. The programme included an automatic alert. Systematic sampling of patients with risk factors hospitalized in non-ICU settings detected nearly 50% of carriers at admission. The proportion of MRSA imported into our hospital varied from 35.4% without any screening programme to 71.8% when all components of our screening programme were considered (P<10(-4)). The ICP varied from 3.1% (31/985) with the complete programme to 10.4% (31/297) without any screening programme (P<10(-6)). Screening patients with risk factors for MRSA carriage hospitalized in non-ICU wards resulted in a 51% increase of the calculated proportion of imported strains and a 58% decrease of the ICP. The two studied indicators were strongly dependent on the screening strategy for MRSA carriers implemented at admission. The screening strategy for patients admitted to non-ICU wards who have risk factors for MRSA carriage seems to be the determinant for the interpretation of certain risk-adjusted indicators of MRSA cross-transmission. Comparisons of these indicators must consider the setting in which the screening programmes are implemented.

[Acinetobacter, a nosocomial pathogen. Contribution of experimental models]. / Acinetobacter, agent d'infections nosocomiales. Apport des modèles expérimentaux.

EPIDEMIOLOGY: The increasing importance of Acinetobacter as a nosocomial pathogen responsible for outbreaks in intensive care units has been pointed out for twenty years. Today Acinetobacter infections are essentially pneumonia in patients under mechanical ventilation. EXPERIMENTAL MODELS: Most clinical isolates are resistant to b-lactam antibiotics as well as to other drugs. Animal models represent an essential step between in vivo testing an

[Isolation of three species of Nocardia in a patient receiving long-term corticosteroid therapy]. / Isolement de trois espèces différentes de Nocardia chez un patient recevant une corticothérapie au long cours.

INTRODUCTION: Nocardia are saprophyte bacteria of the environment responsible for systemic infections in immunodepressed patients, due essentially to long-term corticosteroids. OBSERVATION: A patient having received corticosteroids for sarcoidoses for a year was hospitalised because of disseminated granulomatosis (neurological, respiratory, abdominal and cutaneous). Culture of various bacteriological samples isolated three species of Nocardia: N. otitidiscaviarum in uretheral pus and pus from the right gland, N. nova and N. asteroides in respiratory samples (protected distal sampling and broncho-alveolar washing). COMMENTS: Other than the mixed Nocardia infections described habitually, infections with two different species of Nocardia have recently been reported. Our case report is the first to have isolated three concomitant species of Nocardia.

[Nocardia and human nocardiosis]. / Nocardia i nokardiozy.

Nocardia spp. are pathogens commonly found in soil worldwide, and they cause mostly opportunistic infections in humans and animals, complicating both immunodepressive states and primary diseases. Nocardiosis is difficult to proper microbiological and clinical diagnosis because of its non-specific symptoms, which manifest as the cutaneous and sub-cutaneous infections, lung symptoms and the dissemination through the bloodstream to other organs. General characteristics of Nocardia, human nocardiosis as well as the microbiological diagnostics routine and treatment are discussed.

Lyme endocarditis.

Lyme borreliosis is a common tick-borne disease with a wide variety of clinical manifestations. Cardiac involvement has been reported during both the acute phase (atrioventricular block, pericarditis) and the chronic stage (dilated cardiomyopathy), but is rare (<5%). Here we describe the first case of Borrelia afzelii Lyme endocarditis, in a 61-year-old man living in an endemic area of France. The diagnosis was confirmed by detection of B. afzelii DNA in the mitral valve by specific real-time PCR. He was treated empirically with amoxicillin for 6 weeks and remains well 12 months later.

[Chronic subdural hematoma infected by Campylobacter fetus: case report]. / Infection d'hématome sous-dural chronique à Campylobacter fetus : à propos d'un cas.

We report here a rare case of chronic subdural hematoma infected by Campylobacter fetus in a 86-year-old woman. She was admitted for confusion and disorientation in a context of high fever and diarrhoea. After two surgeries, the evolution was finally good with a combination of antibiotics (amoxicillin and clindamycin). Chronic subdural hematoma is a potential site for bacterial infection. Our case suggests that C. fetus infection should be suspected in elderly patients presenting with fever and enteritis. The frequency of such cases may be underestimated, due to the difficult diagnosis of C. fetus. It is also suspected that C. fetus could play a role in the recurrence of hematoma, because of its vessel tropism.

Efficacies of cefepime, ceftazidime, and imipenem alone or in combination with amikacin in rats with experimental pneumonia due to ceftazidime-susceptible or -resistant Enterobacter cloacae strains.

The antibacterial activities of human regimens of cefepime, ceftazidime, and imipenem alone or in combination with amikacin against an isogenic pair of Enterobacter cloacae strains (wild type and its corresponding derepressed cephalosporinase mutant) were compared by using our nonlethal model of pneumonia with 180 immunocompetent rats. Compared with untreated animals, all beta-lactam-treated rats, except those inoculated with the mutant isolate and receiving ceftazidime, had significantly lower bacterial counts in their lungs 60 h after the onset of therapy. Although the combination of a beta-lactam and amikacin was more bactericidal than each corresponding antimicrobial agent alone, true synergy was noted only with cefepime and imipenem against the constitutive derepressed strain.

Dissemination of CTX-M-type beta-lactamases among clinical isolates of Enterobacteriaceae in Paris, France.

We analyzed 19 clinical isolates of the family Enterobacteriaceae (16 Escherichia coli isolates and 3 Klebsiella pneumoniae isolates) collected from four different hospitals in Paris, France, from 2000 to 2002. These strains had a particular extended-spectrum cephalosporin resistance profile characterized by a higher level of resistance to cefotaxime and aztreonam than to ceftazidime. The bla(CTX-M) genes encoding these beta-lactamases were involved in this resistance, with a predominance of bla(CTX-M-15). Ten of the 19 isolates produced both TEM-1- and CTX-M-type enzymes. One strain (E. coli TN13) expressed CMY-2, TEM-1, and CTX-M-14. bla(CTX-M) genes were found on large plasmids. In 15 cases the same insertion sequence, ISEcp1, was located upstream of the 5' end of the bla(CTX-M) gene. In one case we identified an insertion sequence designated IS26. Examination of the other three bla(CTX-M) genes by cloning, sequencing, and PCR analysis revealed the presence of a complex sul1-type integron that includes open reading frame ORF513, which carries the bla gene and the surrounding DNA. Five isolates had the same plasmid DNA fingerprint, suggesting clonal dissemination of CTX-M-15-producing strains in the Paris area.