Mediterranean spotted fever in the elderly: a prospective cohort study.

The objective of this study is to evaluate the characteristics and outcome of elderly patients with Mediterranean spotted fever (MSF). This study was a prospective observational cohort study of all adult cases with confirmed MSF treated in a teaching hospital (1984-2015) to compare the characteristics of elderly patients (> 65 years) with younger adults. We identified 263 adult patients with MSF, and 53 (20.2%) were elderly. Severe MSF was more frequent in the elderly (26.4% vs. 10.5%; p = 0.002). Gastrointestinal symptoms, impaired consciousness, lung infiltrate, oedema, acute hearing loss, raised alanine transaminase, hyponatremia, and thrombocytopenia occurred more frequently in elderly patients, and arthromyalgia occurred less frequently. Most patients were treated with a single-day doxycycline regimen (two oral doses of 200 mg for 1 day). All patients recovered uneventfully. Fever disappeared 2.55 ± 1.16 days after treatment initiation in elderly patients, and the remaining symptoms disappeared after 3.65 ± 1.42 days. These figures were similar to non-elderly patients. Severe MSF was more frequent in elderly patients. Some clinical manifestations occurred with different frequencies in the elderly compared with younger patients. Single-day doxycycline therapy is an effective and well-tolerated treatment for MSF in elderly patients.

Prospective Cohort Study of Single-Day Doxycycline Therapy for Mediterranean Spotted Fever.

The objective of this study is to evaluate the results of single-day doxycycline therapy for Mediterranean spotted fever (MSF). This is a prospective cohort study of cases with confirmed MSF treated with the single-day doxycycline regimen in a teaching hospital from 1990 to 2015. Patients received two oral doses of 200 mg of doxycycline for 1 day. The outcomes evaluated were the time interval between the start of treatment and apyrexia, the time interval between the start of treatment and disappearance of other symptoms, and the adverse reactions to treatment and death. The study included 158 subjects, 18 of whom (11.4%) had a severe form of MSF and 31 (19.6%) were >65 years. The interval between onset of symptoms and start of treatment was 4.31 ± 1.54 days. All patients recovered uneventfully. Fever disappeared 2.55 ± 1.14 days after the start of treatment. The remaining symptoms (headache, arthromyalgia) disappeared 3.63 ± 1.35 days after the start of treatment. Only one patient had a delay in reaching apyrexia (8 days). The fever disappeared somewhat later in severe cases (median, 3 days; interquartile range [IQR], 2 to 4 days) than in nonsevere cases (median, 2 days; IQR, 2 to 3 days). Likewise, the remaining symptoms disappeared later in severe cases (median, 5 days; IQR, 4 to 6 days) than in nonsevere cases (median, 3 days; IQR, 3 to 4 days). The outcome was similar in both elderly and nonelderly patients. Eight patients had mild adverse effects possibly related to treatment. The results of the study confirm that single-day doxycycline therapy is an effective and well-tolerated treatment for MSF, including elderly patients and severe cases.

Epidemiology and risk factors for infections due to AmpC ß-lactamase-producing Escherichia coli.

OBJECTIVES: To describe the prevalence and risk factors for infection due to AmpC ß-lactamase-producing Escherichia coli (AmpC-EC). METHODS: For the prevalence study, all clinical isolates of E. coli with reduced susceptibility to third-generation cephalosporins were prospectively included from June 2010 to November 2011. For risk factor analysis, a case-control study was conducted. Cases were patients with an infection due to AmpC-EC. Controls were patients infected with cephalosporin-susceptible E. coli, matched 1 : 2. Detection of blaAmpC genes was done with a multiplex AmpC-PCR, and hyperproduction of E. coli chromosomal blaAmpC by quantitative RT-PCR. Alteration of the blaAmpC promoter was studied by PCR and sequencing. RESULTS: We identified 243 (1.1%) AmpC-EC strains out of 21 563 clinical isolates. Three cases with strains carrying ESBLs, 18 strains that were considered due to colonization and 8 cases lost to clinical follow-up were excluded. Finally, 214 cases were included in the analysis. Ninety-one cases (42.5%) and 269 (62.8%) controls were strictly community acquired (P < 0.001). Thirty-five (16.3%) cases and 186 controls (43.5%) did not have any identifiable risk factor (P < 0.001). Among cases, 158 (73.8%) were found to harbour an acquired AmpC (73.4% CMY-2). Previous use of fluoroquinolones [OR 2.6 (95% CI 1.12-3.36); P = 0.008] was independently associated with AmpC-EC in the multivariate analysis. CONCLUSIONS: Prevalence of AmpC in E. coli remains low in our area. Plasmid acquisition (CMY type) represents the main mechanism of AmpC production. A high proportion of community-acquired isolates and patients with no identifiable risk factors were found. Previous use of fluoroquinolones was identified as a risk factor.

Molecular characterisation of acquired and overproduced chromosomal blaAmpC in Escherichia coli clinical isolates.

Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine the prevalence of isolates with acquired AmpC (ac-AmpC) and/or overproduced chromosomal AmpC (c-AmpC). Mechanisms involved in blac-AmpC overexpression, blaac-AmpC and the plasmids associated with their distribution as well as the prevalence of plasmid-mediated quinolone resistance (PMQR) in AmpC-producing isolates were also determined. Isolates were selected according to their resistance phenotype. blaac-AmpC, alterations in the blac-AmpC promoter/attenuator, and PMQR genes [qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA] were characterised by PCR and sequencing. blac-AmpC expression was determined by qRT-PCR. Population structure analysis was performed using PFGE, MLST and phylogenetic group PCR. Plasmids carrying blaac-AmpC were characterised by PCR-based replicon typing and S1-PFGE. IncI1 and IncF plasmids were also analysed by plasmid MLST and replicon sequence typing, respectively. Among 21563 E. coli isolates, 240 (1.1%) overproduced AmpC ß-lactamases, including 180 (75.0%) harbouring ac-AmpC (132 CMY-2 variants and 48 DHA-1) and 60 (25.0%) c-AmpC enzymes. Three mutation profiles in the blac-AmpC promoter/attenuator were associated with a 72.5-, 19.9- and 5.8-fold increased expression, respectively. Moreover, 63.3% of ac-AmpC and 43.3% of c-AmpC isolates belonged to B2, D, E or F phylogenetic groups. PMQR was found in 31% of ac-AmpC isolates [38 qnrB4, 8 aac(6')-Ib-cr, 6 qnrS1 and 3 qnrB19] and in 10% of c-AmpC isolates [5 aac(6')-Ib-cr and 1 qnrS1]. IncI1-ST12 and IncF were associated with blaCMY-2 and blaDHA-1, respectively. These results suggest that ac-AmpC ß-lactamases were the main mechanism of AmpC production. Isolates and plasmids both showed high genetic diversity.