Colistin resistance in a clinical Acinetobacter baumannii strain appearing after colistin treatment: effect on virulence and bacterial fitness.

The fitness and virulence costs associated with the clinical acquisition of colistin resistance by Acinetobacter baumannii were evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coinfecting of 9.31 and 6.97 log10 CFU/g, respectively, with an in vivo competition index of 0.016. Moreover, CS01 was more virulent than CR17 with respect to mortality and time to death.

Prognostic factors in left-sided endocarditis: results from the andalusian multicenter cohort

Despite medical advances, mortality in infective endocarditis (IE) is still very high. Previous studies on prognosis in IE have observed conflicting results. The aim of this study was to identify predictors of in-hospital mortality in a large multicenter cohort of left-sided IE.Methods An observational multicenter study was conducted from January 1984 to December 2006 in seven hospitals in Andalusia, Spain. Seven hundred and five left-side IE patients were included. The main outcome measure was in-hospital mortality. Several prognostic factors were analysed by univariate tests and then by multilogistic regression model. Results.The overall mortality was 29.5% (25.5% from 1984 to 1995 and 31.9% from 1996 to 2006; Odds Ratio 1.25; 95% Confidence Interval: 0.97-1.60; p = 0.07). In univariate analysis, age, comorbidity, especially chronic liver disease, prosthetic valve, virulent microorganism such as Staphylococcus aureus, Streptococcus agalactiae and fungi, and complications (septic shock, severe heart failure, renal insufficiency, neurologic manifestations and perivalvular extension) were related with higher mortality. Independent factors for mortality in multivariate analysis were: Charlson comorbidity score (OR: 1.2; 95% CI: 1.1-1.3), prosthetic endocarditis (OR: 1.9; CI: 1.2-3.1), Staphylococcus aureus aetiology (OR: 2.1; CI: 1.3-3.5), severe heart failure (OR: 5.4; CI: 3.3-8.8), neurologic manifestations (OR: 1.9; CI: 1.2-2.9), septic shock (OR: 4.2; CI: 2.3-7.7), perivalvular extension (OR: 2.4; CI: 1.3-4.5) and acute renal failure (OR: 1.69; CI: 1.0-2.6). Conversely, Streptococcus viridans group etiology (OR: 0.4; CI: 0.2-0.7) and surgical treatment (OR: 0.5; CI: 0.3-0.8) were protective factors.Conclusions Several characteristics of left-sided endocarditis enable selection of a patient group at higher risk of mortality. This group may benefit from more specialised attention in referral centers and should help to identify those patients who might benefit from more aggressive diagnostic and/or therapeutic procedures.

Necrotising pneumonia due to influenza A (H1N1) and community-acquired methicillin-resistant Staphylococcus aureus clone USA300: successful management of the first documented paediatric case.

Necrotising pneumonia in young, previously healthy patients due to Panton–Valentine leucocidin (PVL) producing Staphylococcus aureus has been increasingly recognised. PVL pneumonia is often associated with influenza co-infection and high mortality. This case report describes the successful management of the first documented paediatric case of a previous healthy adolescent who developed necrotising pneumonia due to community-acquired methicillin-resistant (CA-MRSA) clone USA300 with pandemic influenza A (H1N1) co-infection, and highlights the importance of early recognition and initiation of appropriate therapy for this potentially fatal co-infection. PCR remains the gold standard to diagnose pandemic H1N1 since it may not be detected by rapid antigen tests. Bacterial necrotising pneumonia should be suspected in those presenting with worsening flu-like symptoms and clinical and/or radiological evidence of PVL infection (multifocal infiltrates, effusion and cavitation). These patients may benefit from the administration of toxin neutralising agents. In light of the current H1N1 pandemic, healthcare professionals will be increasingly confronted with this clinical scenario.

Acquisition and cross-transmission of Staphylococcus aureus in European intensive care units

Objective. To study the acquisition and cross-transmission of Staphylococcus aureus in different intensive care units (ICUs). Methods. We performed a multicenter cohort study. Six ICUs in 6 countries participated. During a 3-month period at each ICU, all patients had nasal and perineal swab specimens obtained at ICU admission and during their stay. All S. aureus isolates that were collected were genotyped by spa typing and multilocus variable-number tandem-repeat analysis typing for cross-transmission analysis. A total of 629 patients were admitted to ICUs, and 224 of these patients were found to be colonized with S. aureus at least once during ICU stay (22% were found to be colonized with methicillin-resistant S. aureus [MRSA]). A total of 316 patients who had test results negative for S. aureus at ICU admission and had at least 1 follow-up swab sample obtained for culture were eligible for acquisition analysis. Results. A total of 45 patients acquired S. aureus during ICU stay (31 acquired methicillin-susceptible S. aureus [MSSA], and 14 acquired MRSA). Several factors that were believed to affect the rate of acquisition of S. aureus were analyzed in univariate and multivariate analyses, including the amount of hand disinfectant used, colonization pressure, number of beds per nurse, antibiotic use, length of stay, and ICU setting (private room versus open ICU treatment). Greater colonization pressure and a greater number of beds per nurse correlated with a higher rate of acquisition for both MSSA and MRSA. The type of ICU setting was related to MRSA acquisition only, and the amount of hand disinfectant used was related to MSSA acquisition only. In 18 (40%) of the cases of S. aureus acquisition, cross-transmission from another patient was possible. Conclusions. Colonization pressure, the number of beds per nurse, and the treatment of all patients in private rooms correlated with the number of S. aureus acquisitions on an ICU. The amount of hand disinfectant used was correlated with the number of cases of MSSA acquisition but not with the number of cases of MRSA acquisition. The number of cases of patient-to-patient cross-transmission was comparable for MSSA and MRSA.

Mutant prevention concentrations of fluoroquinolones for Enterobacteriaceae expressing the plasmid-carried quinolone resistance determinant qnrA1.

The influence of qnrA1 on the development of quinolone resistance in Enterobacteriaceae was evaluated by using the mutant prevention concentration parameter. The expression of qnrA1 considerably increased the mutant prevention concentration compared to strains without this gene. In the presence of qnrA1, mutations in gyrA and parC genes were easily selected to produce high levels of quinolone resistance.

In vitro activity of fosfomycin against extended-spectrum-beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: comparison of susceptibility testing procedures

The agar dilution, broth microdilution, and disk diffusion methods were compared to determine the in vitro susceptibility of 428 extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae to fosfomycin. Fosfomycin showed very high activity against all ESBL-producing strains. Excellent agreement between the three susceptibility methods was found for E. coli, whereas marked discrepancies were observed for K. pneumoniae.

Diagnostic accuracy, effectiveness and cost for cognitive impairment and dementia screening of three short cognitive tests applicable to illiterates

BACKGROUND Illiteracy, a universal problem, limits the utilization of the most widely used short cognitive tests. Our objective was to assess and compare the effectiveness and cost for cognitive impairment (CI) and dementia (DEM) screening of three short cognitive tests applicable to illiterates. METHODS Phase III diagnostic test evaluation study was performed during one year in four Primary Care centers, prospectively including individuals with suspicion of CI or DEM. All underwent the Eurotest, Memory Alteration Test (M@T), and Phototest, applied in a balanced manner. Clinical, functional, and cognitive studies were independently performed in a blinded fashion in a Cognitive Behavioral Neurology Unit, and the gold standard diagnosis was established by consensus of expert neurologists on the basis of these results. Effectiveness of tests was assessed as the proportion of correct diagnoses (diagnostic accuracy [DA]) and the kappa index of concordance (k) with respect to gold standard diagnoses. Costs were based on public prices at the time and hospital accounts. RESULTS The study included 139 individuals: 47 with DEM, 36 with CI, and 56 without CI. No significant differences in effectiveness were found among the tests. For DEM screening: Eurotest (k = 0.71 [0.59-0.83], DA = 0.87 [0.80-0.92]), M@T (k = 0.72 [0.60-0.84], DA = 0.87 [0.80-0.92]), Phototest (k = 0.70 [0.57-0.82], DA = 0.86 [0.79-0.91]). For CI screening: Eurotest (k = 0.67 [0.55-0.79]; DA = 0.83 [0.76-0.89]), M@T (k = 0.52 [0.37-0.67]; DA = 0.80 [0.72-0.86]), Phototest (k = 0.59 [0.46-0.72]; DA = 0.79 [0.71-0.86]). There were no differences in the cost of DEM screening, but the cost of CI screening was significantly higher with M@T (330.7 ± 177.1 €, mean ± sd) than with Eurotest (294.1 ± 195.0 €) or Phototest (296.0 ± 196. 5 €). Application time was shorter with Phototest (2.8 ± 0.8 min) than with Eurotest (7.1 ± 1.8 min) or M@T (6.8 ± 2.2 min). CONCLUSIONS Eurotest, M@T, and Phototest are equally effective. Eurotest and Phototest are both less expensive options but Phototest is the most efficient, requiring the shortest application time.

A validated clinical approach for the management of aspergillosis in critically ill patients: ready, steady, go!

The clinical relevance of recovering Aspergillus species in intensive care unit patients is unknown. Diagnosis of invasive pulmonary aspergillosis is extremely difficult because there are no specific tests sensitive enough to detect it. The rapidly fatal prognosis of this infection without treatment justifies early antifungal therapy. A clinical algorithm may aid clinicians to manage critically ill patients from whose respiratory specimens Aspergillus spp. have been isolated. This new tool needs to be validated in a large cohort of patients before it can be recommended.

Hepatic safety of antibiotics used in primary care

Antibiotics used by general practitioners frequently appear in adverse-event reports of drug-induced hepatotoxicity. Most cases are idiosyncratic (the adverse reaction cannot be predicted from the drug's pharmacological profile or from pre-clinical toxicology tests) and occur via an immunological reaction or in response to the presence of hepatotoxic metabolites. With the exception of trovafloxacin and telithromycin (now severely restricted), hepatotoxicity crude incidence remains globally low but variable. Thus, amoxicillin/clavulanate and co-trimoxazole, as well as flucloxacillin, cause hepatotoxic reactions at rates that make them visible in general practice (cases are often isolated, may have a delayed onset, sometimes appear only after cessation of therapy and can produce an array of hepatic lesions that mirror hepatobiliary disease, making causality often difficult to establish). Conversely, hepatotoxic reactions related to macrolides, tetracyclines and fluoroquinolones (in that order, from high to low) are much rarer, and are identifiable only through large-scale studies or worldwide pharmacovigilance reporting. For antibiotics specifically used for tuberculosis, adverse effects range from asymptomatic increases in liver enzymes to acute hepatitis and fulminant hepatic failure. Yet, it is difficult to single out individual drugs, as treatment always entails associations. Patients at risk are mainly those with previous experience of hepatotoxic reaction to antibiotics, the aged or those with impaired hepatic function in the absence of close monitoring, making it important to carefully balance potential risks with expected benefits in primary care. Pharmacogenetic testing using the new genome-wide association studies approach holds promise for better understanding the mechanism(s) underlying hepatotoxicity.

A cohort study of routinely used sepsis biomarkers and 28-day mortality.

The evaluation of sepsis severity is complicated by the highly variable and nonspecific nature of clinical signs and symptoms. We studied routinely used biomarkers together with clinical parameters to compare their prognostic value for severe sepsis and evaluate their usefulness.

Brote de brucelosis interprovincial por ingesta de queso fresco sin higienizar

Goal: To study an August 2004 outbreak of brucellosis notified in Velez-Rubio (Almeria) and to determine the source of that infection as well as its transmission mechanisms, in addition to proposing preventive measures. Methodology: Descriptive study and paired case controls (three controls were selected for each case). Setting: Health Centers in de Vélez-Rubio (Almeria) and Alcalá de Guadaira (Seville). Population: Suspected/probable case: a person with compatible clinical symptoms and positive brusella agglutination diagnosed between July 2005 and March 2005. Confirmed case: in addition to identifying the causal agent, laboratory test results resulted in a confirmation. Interventions: Report forms, epidemiological surveys, clinical histories, and laboratory tests were used as sources of data. Odds ratios (OR) and confidence intervals were calculated to study the relationship among cases, sources of infection, and transmission mechanisms. The Chi Square test and Yates correction were employed. Results: 10 cases were identified (9 in Almeria and 1 in Seville), 8 of them pobable and 2 confirmed, in persons between the ages of 45 and 81. The symptoms first appeared between the months of May and September 2005. Fever was the most frequent symptom (100%). The OR for the consumption of fresh, non.-pasteurized cheese was 112 (CI 4,48-16968,94), p< 0,001. Infected animals were intervened. Conclusions: The inter-provincial outbreak of brucellosis was confirmed as stemming from the consumption of non-pasteurized cheese sold on the street. The source of infection was identified and the Department of Agriculture carried out the necessary actions.

Virulence profiles of bacteremic extended-spectrum β-lactamase-producing Escherichia coli: association with epidemiological and clinical features.

There is scarce data about the importance of phylogroups and virulence factors (VF) in bloodstream infections (BSI) caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC). A prospective multicenter Spanish cohort including 191 cases of BSI due to ESBLEC was studied. Phylogroups and 25 VF genes were investigated by PCR. ESBLEC were classified into clusters according to their virulence profiles. The association of phylogropus, VF, and clusters with epidemiological features were studied using multivariate analysis. Overall, 57.6%, 26.7%, and 15.7% of isolates belonged to A/B1, D and B2 phylogroups, respectively. By multivariate analysis (adjusted OR [95% CI]), virulence cluster C2 was independently associated with urinary tract source (5.05 [0.96-25.48]); cluster C4 with sources other than urinary of biliary tract (2.89 [1.05-7.93]), and cluster C5 with BSI in non-predisposed patients (2.80 [0.99-7.93]). Isolates producing CTX-M-9 group ESBLs and from phylogroup D predominated among cluster C2 and C5, while CTX-M-1 group of ESBL and phylogroup B2 predominantes among C4 isolates. These results suggest that host factors and previous antimicrobial use were more important than phylogroup or specific VF in the occurrence of BSI due to ESBLEC. However, some associations between virulence clusters and some specific epidemiological features were found.

Candidiasis cutánea generalizada en recién nacido a término.

INTRODUCTION Cutaneous candidiasis is a disease that affects children as well as adults. The presentation may be localized or systemic, and with multiple etiological agents. The most prevalent infecting species in children differs from that of the adult. OBJECTIVE A case is presented where a congenital cutaneous candidiasis was transmitted to the child during birth. MATERIALS AND METHODS A full term newborn was exposed to a subclinical vaginal candidiasis infection, and 24 hr after birth, developed congenital cutaneous candidiasis. The etiological agent was Candida albicans, and was associated with sepsis and respiratory distress. Blood cultures, cutaneous biopsy of vesicular lesions, blood tests and lumbar puncture were performed. RESULTS Biochemistry and blood count showed a CRP of 5.7 mg/dl, leukocytosis with left shift and mild anemia. After 24 hr, the blood analyses showed an increase in a CRP (7.8 mg/dl) and increased progressively for three days; consequently, a lumbar puncture was performed. Blood culture was positive for Staphylococcus aureus. Cutaneous biopsy confirmed the cutaneous candidiasis. CONCLUSIONS The early diagnosis is essential to prevent complications derived by the Candida albicans in newborns.

Iron overload, an immunosuppression marker in HIV-infected patients.

Purpose: Iron overload (IO) has been associated with increased cardiovascular risk (CVR) and metabolic syndrome (MS) in the general population; both elevated CVR and MS are frequent in HIV- patients. Our aim was to analyze the prevalence of IO in a cohort of asymptomatic patients with HIV infection, and related factors. Methods: Cross-sectional study of a cohort of HIV outpatients in regular follow-up. Demographic, epidemiological, clinical, analytical and therapeutic data were collected. Patients completed a questionnaire about CVR factors and 10-year CV disease risk estimation (Framingham score), underwent a physical exam, and a fasting blood analysis. IO was defined as a plasma ferritin level higher than 200 m/L in women and 300 m/L in men. Results: 571 patients (446 men, 125 women), with a mean age of 43.2 years, sexual transmission of HIV in 68.5%, median CD4 count 474 cell/μL (IQR: 308-666), and 36.3% Aids cases 86.2% were on antiretroviral therapy (ART), and 74.8% of them had undetectable HIV viral load 14.6% met MS criteria, and mean CVR at 10 years was 6.67%. IO was detected in 11% of cases. Patients with IO were more immunosuppressed (CD4 count 369 vs 483/μL, p<0.0001), presented a higher prevalence of detectable HIV viral load (17.6% vs 8.9%; p<0.005), and of Aids cases (14.9% vs 8.7%; p<0.023), and lower plasma levels of cholesterol, HDLc and LDLc (154 vs 183, 34 vs 43, 93 vs 110 mg/dL, respectively; p<0.0001. In the multivariate analysis, the only related factor was CD4 count <350 cell/μL (OR 2.86, 95% CI 1.6-4.9; p<0.0001). IO was not associated with CVR nor with MS. Conclusions: IO is not uncommon in HIV patients, and it is only related with immunosuppression defined as CD4 count <350 cell/ mL, and in contrast to general population, it is not related with increased CVR nor with MS.

Inoculum effect on the efficacies of amoxicillin-clavulanate, piperacillin-tazobactam, and imipenem against extended-spectrum β-lactamase (ESBL)-producing and non-ESBL-producing Escherichia coli in an experimental murine sepsis model.

Escherichia coli is commonly involved in infections with a heavy bacterial burden. Piperacillin-tazobactam and carbapenems are among the recommended empirical treatments for health care-associated complicated intra-abdominal infections. In contrast to amoxicillin-clavulanate, both have reduced in vitro activity in the presence of high concentrations of extended-spectrum β-lactamase (ESBL)-producing and non-ESBL-producing E. coli bacteria. Our goal was to compare the efficacy of these antimicrobials against different concentrations of two clinical E. coli strains, one an ESBL-producer and the other a non-ESBL-producer, in a murine sepsis model. An experimental sepsis model {~5.5 log10 CFU/g [low inoculum concentration (LI)] or ~7.5 log(10) CFU/g [high inoculum concentration (HI)]} using E. coli strains ATCC 25922 (non-ESBL producer) and Ec1062 (CTX-M-14 producer), which are susceptible to the three antimicrobials, was used. Amoxicillin-clavulanate (50/12.5 mg/kg given intramuscularly [i.m.]), piperacillin-tazobactam (25/3.125 mg/kg given intraperitoneally [i.p.]), and imipenem (30 mg/kg i.m.) were used. Piperacillin-tazobactam and imipenem reduced spleen ATCC 25922 strain concentrations (-2.53 and -2.14 log10 CFU/g [P < 0.05, respectively]) in the HI versus LI groups, while amoxicillin-clavulanate maintained its efficacy (-1.01 log10 CFU/g [no statistically significant difference]). Regarding the Ec1062 strain, the antimicrobials showed lower efficacy in the HI than in the LI groups: -0.73, -1.89, and -1.62 log10 CFU/g (P < 0.05, for piperacillin-tazobactam, imipenem, and amoxicillin-clavulanate, respectively, although imipenem and amoxicillin-clavulanate were more efficacious than piperacillin-tazobactam). An adapted imipenem treatment (based on the time for which the serum drug concentration remained above the MIC obtained with a HI of the ATCC 25922 strain) improved its efficacy to -1.67 log10 CFU/g (P < 0.05). These results suggest that amoxicillin-clavulanate could be an alternative to imipenem treatment of infections caused by ESBL- and non-ESBL-producing E. coli strains in patients with therapeutic failure with piperacillin-tazobactam.