Genetic and biochemical characterization of OXA-405, an OXA-48-Type extended-spectrum β-lactamase without significant carbapenemase activity

The epidemiology of carbapenemases worldwide is showing that OXA-48 variants are becoming the predominant carbapenemase type in Enterobacteriaceae in many countries. However, not all OXA-48 variants possess significant activity toward carbapenems (e.g., OXA-163). Two Serratia marcescens isolates with resistance either to carbapenems or to extended-spectrum cephalosporins were successively recovered from the same patient. A genomic comparison using pulsed-field gel electrophoresis and automated Rep-PCR typing identified a 97.8% similarity between the two isolates. Both strains were resistant to penicillins and first-generation cephalosporins. The first isolate was susceptible to expanded-spectrum cephalosporins, was resistant to carbapenems, and had a significant carbapenemase activity (positive Carba NP test) related to the expression of OXA-48. The second isolate was resistant to expanded-spectrum cephalosporins, was susceptible to carbapenems, and did not express a significant imipenemase activity, (negative for the Carba NP test) despite possessing a blaOXA-48-type gene. Sequencing identified a novel OXA-48-type β-lactamase, OXA-405, with a four-amino-acid deletion compared to OXA-48. The blaOXA-405 gene was located on a ca. 46-kb plasmid identical to the prototype IncL/M blaOXA-48-carrying plasmid except for a ca. 16.4-kb deletion in the tra operon, leading to the suppression of self-conjugation properties. Biochemical analysis showed that OXA-405 has clavulanic acid-inhibited activity toward expanded-spectrum activity without significant imipenemase activity. This is the first identification of a successive switch of catalytic activity in OXA-48-like β-lactamases, suggesting their plasticity. Therefore, this report suggests that the first-line screening of carbapenemase producers in Enterobacteriaceae may be based on the biochemical detection of carbapenemase activity in clinical settings

Infected breast milk associated with late-onset and recurrent group B streptococcal infection in neonatal twins: a genetic analysis

The original publication is available at www.springerlink.comInternational audienceAsymptomatic excretion of group B streptococcus (GBS) in breast milk may be an underrecognized cause of neonatal and recurrent infection. We report the case of late-onset and recurrent infection in newborn twins resulting from ingestion of maternal breast milk infected with GBS. Genetic analysis of isolates is equally presented

Clinical Isolates of Staphylococcus aureus with Ribosomal Mutations Conferring Resistance to Macrolides

Six strains of Staphylococcus aureus isolated from cystic fibrosis patients after treatment with azithromycin were cross-resistant to azithromycin and erythromycin. None of the isolates contained erm or msr(A) genes, but they all carried either A2058G/U or A2059G mutations within the rrl genes, with a majority of the rRNA copies bearing the mutation. One strain displayed an additional mutation in the rplV gene, encoding the L22 ribosomal protein

Extra-genito-urinary location of Oligella urethralis

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SHV-12-Like Extended-Spectrum-β-Lactamase-Producing Strains of Salmonella enterica Serotypes Babelsberg and Enteritidis Isolated in France among Infants Adopted from Mali

From December 2002 to June 2003, 14 cultures of Salmonella enterica serotype Babelsberg and 6 cultures of serotype Enteritidis, isolated in France from internationally adopted children, were identified at the French National Reference Center for Salmonella. All serotype Babelsberg isolates were related, as determined by pulsed-field gel electrophoresis, and all serotype Enteritidis strains displayed the same phage type. All serotype Enteritidis and seven serotype Babelsberg isolates produced an SHV-12-like extended-spectrum β-lactamase as determined by sequencing of PCR products and by isoelectrofocusing. Some serotype Enteritidis isolates exhibited additional antimicrobial resistance (aminoglycosides, tetracycline, chloramphenicol, sulfonamides, and trimethoprim). Our investigation indicated that these Salmonella isolates were certainly acquired in the same orphanage in Bamako, Mali, before the children were adopted by French families. An inappropriate use of ceftriaxone was probably the cause of the emergence of such strains. There is an urgent need to determine the origin of the contamination and to introduce adequate antibiotic protocols into this orphanage to prevent further transmission and dissemination. Screening for infections and follow-up, adapted to the origin of the internationally adopted children, should be recommended

Statin use does not affect the outcome of acute infection: a prospective cohort study.

International audienceUNLABELLED: Statins are used to prevent atherosclerosis because of their hypolipemic effects. In vitro testing and murine models suggest that statins may affect outcome in sepsis. Our meta-analysis of epidemiological studies in humans confirms that previous statin use appears to have a protective effect on infection rates and outcomes. The studies considered, however, were very different and heterogeneity was high, especially for mortality criteria. OBJECTIVE: To compare outcome for current statin users and nonusers hospitalized with fever, under pragmatic circumstances. DESIGN: Prospective cohort study. SETTING: University Hospital of Brest (France). PARTICIPANTS: Febrile (>38 degrees C) patients older than 40 years, admitted to the hospital on an emergency basis in 2005. Patients' outcome was compared according to their exposure to statins (current user or nonuser). MAIN OUTCOME MEASURES: Mortality, length of hospitalization, admission to ICU and to convalescent homes RESULTS: Of 40 343 patients referred for admission by the emergency department in 2005, 964 patients older than 40 years had a fever higher than 38 degrees C and were included in the study. Statin-user status, however, was available for only 921. The ICU admission rate (relative risk: 4.69; 95% CI: 2.42-9.08) was significantly higher (p=0.009) among statin users (n=139) than nonusers (n=782). The groups had similar lengths of hospitalization and similar rates of mortality and of convalescent home admissions. CONCLUSION: Our study does not confirm that statin use affects infection outcome and suggests that previous findings may be associated instead with more cautious care or nonspecific cardiovascular prevention rather than with a specific infection-related effect. Thus, these data support the continuation of statin therapy during physiological aggression, including infection

Helicobacter cinaedi associated with atypical Raynaud syndrome

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Delineation of the basal ganglia in MR images of patients by automatic registration of a multimodal atlas based on histological and MR data

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