[Characteristics of lower respiratory tract infections in the elderly]. / Caractéristiques des infections respiratoires basses chez les sujets âgés.

Pneumonia is more frequent among the elderly and is associated with higher rates of hospitalization and death. The diagnosis of pneumonia in the elderly is a clinical challenge because of its non-typical symptoms and because of a poor diagnostic yield of microbiological analysis. Ageing is associated with specific pathogenesis, modifications in lung performance and modifications in oropharyngeal flora. The management relies on empirical therapy, which takes into account the severity of the infectious episode, the presence of additional risk factors, co-morbidities and institutionalization.

Increase in hospital-acquired bloodstream infections caused by extended spectrum beta-lactamase-producing Escherichia coli in a large French teaching hospital.

Our goal was to determine the characteristics and the mode of acquisition of healthcare-associated bacteraemia due to CTX-M-producing Escherichia coli in a 1,800-bed hospital. Sixteen extended-spectrum beta-lactamase (ESBL)-producing E. coli strains were collected between 2001 and 2006 from patients with bloodstream infections. The incidence density of these infections increased from 0.002 to 0.02 per 1,000 days of hospitalisation during the study period. Most of the strains (87%) produced a CTX-M-type enzyme associated with TEM-1 (86%), OXA-30 (50%), AAC(3)-II (57%), AAC(6') (50%) and QnrS1 (7%). When present (n = 8), the bla (CTX-M-15) gene was always located downstream of the insertion sequence ISEcp1. Co-resistance was generally observed: fluoroquinolones (81%), trimethoprim-sulfamethoxazole (62%) and/or aminoglycosides (69%). Although the strains were found to be genetically unrelated, most of the cases were hospital-acquired (69%) or healthcare-associated (25%), underlining the need for infection control measures to limit the spread of ESBL-producing E. coli in hospital settings.

Phenotypic detection of extended-spectrum beta-lactamase production in Enterobacteriaceae: review and bench guide.

Strains of Enterobacteriaceae producing an extended spectrum beta-lactamase have become a concern in medical bacteriology as regards both antimicrobial treatment and infection control in hospitals. Extended-spectrum beta-lactamase (ESBL) detection tests should accurately discriminate between bacteria producing these enzymes and those with other mechanisms of resistance to beta-lactams, e.g., broad-spectrum beta-lactamases, inhibitor-resistant beta-lactamases and cephalosporinase overproduction. Several phenotypic detection tests, based on the synergy between a third-generation cephalosporin and clavulanate, have been designed: the double-disk synergy test (DDST), ESBL Etests, and the combination disk method. These tests often need to be refined in order for them to detect an ESBL in some bacterial strains, such as those that also overproduce a cephalosporinase. The sensitivity of the DDST can be improved by reducing the distance between the disks of cephalosporins and clavulanate. The use of cefepime, a fourth-generation cephalosporin that is less rapidly inactivated by cephalosporinase than by ESBL, improves the detection of synergy with clavulanate when there is simultaneous stable hyperproduction of a cephalosporinase; alternatively, the cephalosporinase can be inactivated by performing phenotypic tests on a cloxacillin-containing agar. Some beta-lactamases can hydrolyse both third-generation cephalosporins and carbapenems, such as the metallo-beta-lactamases, which are not inhibited by clavulanate, but rather by EDTA. The production of an ESBL masked by a metallo-beta-lactamase can be detected by means of double inhibition by EDTA and clavulanate. Since extended-spectrum Ambler class D oxacillinases are weakly inhibited by clavulanate and not inhibited by EDTA, their detection is difficult in the routine laboratory.

[Prediction of the latency period by cervical ultrasonography in premature rupture of the membranes before term]. / Prédiction de l'intervalle de latence par mesure échographique du col utérin dans la rupture prématurée des membranes avant terme.

OBJECTIVE: To assess the value of ultrasonographic measurement of cervical length for predicting the duration of the latency period from admission to delivery in women with preterm premature rupture of the membranes (PROM). METHOD: Prospective study in 88 women with preterm PROM before 34 weeks of amenorrhea. The median gestational age at admission was of 30.1 weeks. The clinical management included: no digital examination of the uterine cervix, antenatal corticosteroids, antibiotics (amoxicillin & clavulanic acid) for 7 days, and hoding back until 34 weeks. Cervical length at admission was determined with transvaginal ultrasonography. The duration of the latency period was studied in relation with cervical length, serum C-reactive protein (CRP) level and white blood cell (WBC) count at admission. RESULTS: The median latency period was longer in women with a cervical length > or = 25 mm (10 vs 5 days; p = 0.04), but this was not associated with a significant increase in birth weight. The median latency period was also longer in women with CRP < 20 mg/l (10 vs 3 days; p < 0.001) and this was associated with a significant increase in birth weight (1716 +/- 549 vs 1201 +/- 485 g; p < 0.01). Moreover, increased CRP levels were more frequent in women with a cervical length < 25 mm, and cervical length was no more predictive of the duration of the latency period in the subgroup of women with CRP < 20 mg/l and WBC < 20,000 cells/mm3. CONCLUSION: In women with preterm PROM, the latency period from admission to delivery is shorter when cervical length is < 25 mm. However, the clinical value of transvaginal ultrasonography is limited in comparison with serum CRP.