First report of human infection due to Streptococcus devriesei

So far, Streptococcus devriesei, which belongs to the mutans streptococci group, has been incriminated in the formation of caries in Equidae. We report the first human infection due to this species in a 54-year-old man with gangrenous cholecystitis. The patient was treated successfully by cholecystectomy and ceftriaxone.

Mitral endocarditis due to Rothia aeria with cerebral haemorrhage and femoral mycotic aneurysms, first French description

Rothia aeria is a Rothia species from the Micrococcaceae family. We report here the first French R. aeria endocarditis complicated by brain haemorrhage and femoral mycotic aneurysms. Altogether, severity and antimicrobial susceptibility should make us consider the management of R. aeria endocarditis as Staphylococcus aureus methicillin-susceptible endocarditis.

Expression of GDNF transgene in astrocytes improves cognitive deficits in aged rats

Glial cell line-derived neurotrophic factor (GDNF) was assayed for its neurotrophic effects against the neuronal atrophy that causes cognitive deficits in old age. Aged Fisher 344 rats with impairment in the Morris water maze received intrahippocampal injections at the dorsal CA1 area of either a lentiviral vector encoding human GDNF or the same vector encoding human green fluorescent protein as a control. Recombinant lentiviral vectors constructed with human cytomegalovirus promotor and pseudotyped with lyssavirus Mokola glycoprotein specifically transduced the astrocytes in vivo. Astrocyte-secreted GDNF enhanced neuron function as shown by local increases in synthesis of the neurotransmitters acetylcholine, dopamine and serotonin. This neurotrophic effect led to cognitive improvement of the rats as early as 2 weeks after gene transduction. Spatial learning and memory testing showed a significant gain in cognitive abilities due to GDNF exposure, whereas control-transduced rats kept their performance at the chance level. These results confirm the broad spectrum of the neurotrophic action of GDNF and open new gene therapy possibilities for reducing age-related neurodegeneration.

Catalytic and structural properties of IRT-21 beta-lactamase (TEM-77) from a co-amoxiclav-resistant Proteus mirabilis isolate

Proteus mirabilis strain MAG1, a clinical isolate that is resistant to broad-spectrum penicillins and co-amoxiclav, produces inhibitor-resistant TEM (IRT)-21, a novel mutant of TEM beta-lactamase. This enzyme has a pI of 5.2 and is derived from the bla(TEM-1a) gene ancestor. It contains two major amino acid substitutions specific for co-amoxiclav resistance (Leu-69 for Met and Ser-244 for Arg) that have never been found together previously. The dramatic loss of sensitivity to clavulanic acid, the enhancement of K(m) for all beta-lactams and markedly for ticarcillin, and the decrease in the catalytic efficiency makes IRT-21 comparable to the other IRTs with substitutions at position 244 or double substitutions.

Coexistence of SHV-4- and TEM-24-producing Enterobacter aerogenes strains before a large outbreak of TEM-24-producing strains in a French hospital

In 1996, a monitoring program was initiated at the teaching hospital of Amiens, France, and carried out for 3 years. All extended-spectrum beta-lactamase (ESBL)-producing Enterobacter aerogenes isolates recovered from clinical specimens were collected for investigation of their epidemiological relatedness by pulsed-field gel electrophoresis and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and determination of the type of ESBL harbored by isoelectric focusing and DNA sequencing. Molecular typing revealed the endemic coexistence, during the first 2 years, of two clones expressing, respectively, SHV-4 and TEM-24 ESBLs, while an outbreak of the TEM-24-producing strain raged in the hospital during the third year, causing the infection or colonization of 165 patients. Furthermore, this strain was identified as the prevalent clone responsible for outbreaks in many French hospitals since 1996. This study shows that TEM-24-producing E. aerogenes is an epidemic clone that is well established in the hospital's ecology and able to spread throughout wards. The management of the outbreak at the teaching hospital of Amiens, which included the reinforcement of infection control measures, failed to obtain complete eradication of the clone, which has become an endemic pathogen.