Impact of ceftazidime/avibactam versus best available therapy on mortality from infections caused by carbapenemase-producing Enterobacterales (CAVICOR study).

BACKGROUND: Infections caused by carbapenemase-producing Enterobacterales (CPE) are not well represented in pivotal trials with ceftazidime/avibactam. The best strategy for the treatment of these infections is unknown. METHODS: We conducted a multicentre retrospective observational study of patients who received ≥48 h of ceftazidime/avibactam or best available therapy (BAT) for documented CPE infections. The primary outcome was 30 day crude mortality. Secondary outcomes were 21 day clinical response and microbiological response. A multivariate logistic regression model was used to identify factors predictive of 30 day crude mortality. A propensity score to receive treatment with ceftazidime/avibactam was used as a covariate in the analysis. RESULTS: The cohort included 339 patients with CPE infections. Ceftazidime/avibactam treatment was used in 189 (55.8%) patients and 150 (44.2%) received BAT at a median of 2 days after diagnosis of infection. In multivariate analysis, ceftazidime/avibactam treatment was associated with survival (OR 0.41, 95% CI 0.20-0.80; P = 0.01), whereas INCREMENT-CPE scores of >7 points (OR 2.57, 95% CI 1.18-1.5.58; P = 0.01) and SOFA score (OR 1.20, 95% CI 1.08-1.34; P = 0.001) were associated with higher mortality. In patients with INCREMENT-CPE scores of >7 points, ceftazidime/avibactam treatment was associated with lower mortality compared with BAT (16/73, 21.9% versus 23/49, 46.9%; P = 0.004). Ceftazidime/avibactam was also an independent factor of 21 day clinical response (OR 2.43, 95% CI 1.16-5.12; P = 0.02) and microbiological eradication (OR 0.40, 95% CI 0.18-0.85; P = 0.02). CONCLUSIONS: Ceftazidime/avibactam is an effective alternative for the treatment of CPE infections, especially in patients with INCREMENT-CPE scores of >7 points. A randomized controlled trial should confirm these findings.

Pilot randomized controlled trial of a hypnosis intervention for women with bladder pain syndrome.

AIMS: To evaluate the feasibility and acceptability of a randomized controlled trial of a hypnosis intervention for the treatment of bladder pain syndrome/interstitial cystitis (BPS/IC) in women. METHODS: We conducted a parallel arm, non-blinded, pilot randomized controlled trial of standardized hypnosis sessions including a hypnosis web tool versus usual care in adult women with BPS/IC. Pilot study outcomes included feasibility domains: process, resources and management, safety, and acceptability. Clinical outcomes of lower urinary tract symptoms and quality of life were measured using validated questionnaires at baseline and at the end of the 4-week intervention. RESULTS: We randomized 29 out of 30 (96.7%) eligible women. In the hypnosis group, 12 of 15 (80.0%) subjects completed the 4-week intervention and follow up, and 13 of 14 (92.9%) in the usual care group. In the hypnosis group, adherence to the standardized sessions was 80% and participants used the web-based tool for an average of 5.6 ± 2.7 times per week. Scores for emotional distress, relaxation, pain severity and expected bladder symptoms significantly improved during the first two of three planned hypnosis sessions (all p < 0.05). Improvement in quality of life scores was greater in the hypnosis group than the usual care group (-2.6 ± 2.3 vs. -0.9 ± 1.1, p = 0.04). There were no significant between-group differences in urinary symptoms or bladder pain. No adverse events were reported. CONCLUSIONS: A hypnosis intervention for the treatment of bladder pain syndrome/interstitial cystitis is feasible, acceptable, safe, and may improve quality of life.

Ceftaroline for severe community-acquired pneumonia: A real-world two-centre experience in Italy and Spain.

BACKGROUND: Ceftaroline is one of latest additions to the armamentarium for treating community-acquired pneumonia (CAP). This study aimed to describe the outcome of severe CAP (SCAP) in a cohort of hospitalised patients treated with ceftaroline. METHODS: A retrospective, observational study of patients with SCAP treated with ceftaroline in two hospitals in Spain and Italy. The primary objective was to explore 30-day mortality after diagnosis of SCAP. RESULTS: During the study period the following were observed: there were 89 cases of SCAP treated with ceftaroline and 53 cases used in combination with other antibiotics (60%). Overall, 30-day mortality and clinical failure were 20% (18 of 89) and 36% (32 of 89), respectively. Independent predictors of 30-day mortality were: increasing age (OR for 1 year increase 1.0, 95% CI 1.0-1.1, P 0.043), presence of solid neoplasm (OR 4.0, 95% CI 1.0-15.1, P 0.044) and concomitant therapy with oseltamivir (OR 8.5, 95% CI 1.2°57.3, P 0.029). The only independent predictor of clinical failure was the time elapsing from SCAP diagnosis to ceftaroline therapy (OR for each passing day 1.5, 95% CI 1.1-1.9, P 0.003). The clinical success rate was 64% (57 of 89). In the subgroups of patients with proven Streptococcus pneumoniae, methicillin-susceptible Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) infection, clinical success was 83% (10 of 12), 75% (three of four) and 56% (five of nine), respectively. CONCLUSIONS: Considering its spectrum of activity, ceftaroline could represent an important therapeutic option for SCAP. Further studies are needed to identify the precise clinical success rate against MRSA in a larger cohort of patients with SCAP.

Clinical characteristics and prognosis of infections caused by OXA-48 carbapenemase-producing Enterobacteriaceae in patients treated with ceftazidime-avibactam.

BACKGROUND: Ceftazidime-avibactam has in vitro activity against Gram-negative bacilli that produce Class A, C and some D ß-lactamases, and has been successfully used in the treatment of infections caused by cephalosporin and carbapenem-resistant Enterobacteriaceae. However, actual experience in the treatment of OXA-48 carbapenemase-producing Enterobacteriaceae (CPE) is limited. OBJECTIVE: To review the characteristics and prognosis of OXA-48 CPE infections treated with ceftazidime-avibactam since introduction of the drug to the current centre during the period October 2014 to December 2016. METHODS: Retrospective assessment of episodes of infection caused by OXA-48 CPE treated with ceftazidime-avibactam, analysing data collected from infection diagnosis until 90 days after the end of treatment. RESULTS: Twenty-four episodes were analysed. Ceftazidime-avibactam was given as the initial definitive treatment in 15 (62.5%) and as salvage therapy in nine (37.5%). Intraabdominal (seven, 29%), urinary (six, 25%) and respiratory (five, 21%) were the most common sources. The 30-day and 90-day mortality rates were 8.3% and 20.8%, respectively. Clinical cure at 30 days was achieved in 62.5% of episodes. Four (16.7%) patients had adverse events, two of them were related to impaired renal function. Among patients who finished the treatment with ceftazidime-avibactam, seven (35%) were diagnosed with infection recurrence within 90 days of the end of treatment. CONCLUSIONS: From experience, ceftazidime-avibactam is an effective drug for treating infections due to OXA-48 CPE. From these results a better safety profile than the current best available therapy could be expected.

Evaluation of ceftazidime/avibactam for serious infections due to multidrug-resistant and extensively drug-resistant Pseudomonas aeruginosa.

OBJECTIVES: The steady progress in resistance of Pseudomonas aeruginosa (PA) has led to difficulties in treating infections due to multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. Ceftazidime/avibactam (CAZ/AVI) has in vitro activity against many of these strains, however clinical experience with CAZ/AVI is limited. This study aimed to evaluate the characteristics and outcomes of eight patients with infections due to MDR- or XDR-PA treated with CAZ/AVI, including four strains resistant to ceftolozane/tazobactam. METHODS: This was a retrospective descriptive study of patients admitted to a teaching hospital between January 2016 and May 2017 who received CAZ/AVI as initial or continuation therapy for infection due to MDR- and XDR-PA. RESULTS: The sources of infection were hospital-acquired lower respiratory tract infection in five patients (62.5%) and osteomyelitis, meningitis and catheter-related bacteraemia in one patient each. Clinical cure was achieved in 4 patients (50.0%). The 30-day and 90-day mortality rates were 12.5% and 37.5%, respectively. One patient (12.5%) developed encephalopathy that improved with discontinuation of the drug. CONCLUSIONS: CAZ/AVI may be a valuable option for serious infections due to resistant PA.

Antibiotic selection in the treatment of acute invasive infections by Pseudomonas aeruginosa: Guidelines by the Spanish Society of Chemotherapy / Elección del tratamiento antibiótico en la infección invasiva aguda por Pseudomonas aeruginosa: Guía de la Sociedad Española de Quimioterapia

Pseudomonas aeruginosa is characterized by a notable intrinsic resistance to antibiotics, mainly mediated by the expression of inducible chromosomic β-lactamases and the production of constitutive or inducible efflux pumps. Apart from this intrinsic resistance, P. aeruginosa possess an extraordinary ability to develop resistance to nearly all available antimicrobials through selection of mutations. The progressive increase in resistance rates in P. aeruginosa has led to the emergence of strains which, based on their degree of resistance to common antibiotics, have been defined as multidrug resistant, extended-resistant and panresistant strains. These strains are increasingly disseminated worldwide, progressively complicating the treatment of P. aeruginosa infections. In this scenario, the objective of the present guidelines was to review and update published evidence for the treatment of patients with acute, invasive and severe infections caused by P. aeruginosa. To this end, mechanisms of intrinsic resistance, factors favoring development of resistance during antibiotic exposure, prevalence of resistance in Spain, classical and recently appeared new antibiotics active against P. aeruginosa, pharmacodynamic principles predicting efficacy, clinical experience with monotherapy and combination therapy, and principles for antibiotic treatment were reviewed to elaborate recommendations by the panel of experts for empirical and directed treatment of P. aeruginosa invasive infections (AU)

Pseudomonas aeruginosa se caracteriza por una notable resistencia intrínseca a los antibióticos mediada fundamentalmente por la expresión de β-lactamasas cromosómicas inducibles y la producción constitutiva o inducible de bombas de expulsión. Además de esta resistencia intrínseca, P. aeruginosa posee una extraordinaria capacidad para desarrollar resistencia a prácticamente todos los antimicrobianos disponibles a través de la selección de mutaciones. El aumento progresivo de la resistencia en P. aeruginosa ha llevado a la aparición de cepas que, de acuerdo con el grado de resistencia frente a los antibióticos habituales, se han definido como multirresistentes, extensamente resistentes y panresistentes. Estas cepas se están diseminando mundialmente, complicando progresivamente el tratamiento de las infecciones por P. aeruginosa. En este escenario, el objetivo de las presentes recomendaciones es la revisión y puesta al día de la evidencia publicada para el tratamiento de pacientes con infección aguda, invasiva y grave por P. aeruginosa. Con este fin, se han revisado los mecanismos de resistencia intrínseca, factores que favorecen el desarrollo de resistencia durante la exposición a antibióticos, prevalencia de la resistencia en España, antibióticos clásicos así como los de reciente introducción activos frente a P. aeruginosa, principios farmacodinámicos predictores de eficacia, experiencia clínica con tratamientos en monoterapia o terapia combinada y principios del tratamiento antibiótico para elaborar por un panel de xpertos recomendaciones para el tratamiento empírico o dirigido de infecciones invasivas por P. aeruginosa (AU)

Clinical experience with ceftolozane/tazobactam in patients with serious infections due to resistant Pseudomonas aeruginosa.

OBJECTIVES: The incidence of infections caused by multidrug-resistant Pseudomonas aeruginosa (MDR-Pa) has become a concern of increasing relevance nowadays. Ceftolozane/tazobactam (C/T) is a novel fifth-generation cephalosporin/ß-lactamase inhibitor combination with activity against MDR-Pa. METHODS: The clinical records of all patients diagnosed from May 2016 to May 2017 with an infection due to a MDR-Pa treated with C/T were retrospectively reviewed. RESULTS: A total of 23 patients with 24 episodes of infection due to MDR-Pa were included. The minimum inhibitory concentration (MIC) of C/T against MDR-Pa ranged from 0.75-8µg/mL. In 14 cases (58%) the use of C/T was off-label, including 8 respiratory tract infections (RTIs) and 6 skin and soft-tissue infections, whilst in 10 cases the use was for approved indications, including 7 urinary tract infections and 3 intra-abdominal infections. C/T was the first-line therapy in only three cases with a mean±standard deviation treatment duration of 9.3±4 days, and it was associated with another active drug (aminoglycoside or colistin) in 16 cases. The global clinical cure rate was 88% (21/24 episodes), and the 6-week mortality rate was 22% (5/23 patients) being higher in RTIs (37%). In these infections, three patients received 2/1g every 8h (q8h) and were cured without mortality, whilst three (60%) of five patients receiving 1/0.5g q8h died. CONCLUSION: C/T had good clinical responses in different types of infection, including both FDA-accepted and off-label indications. The results support the use of higher doses in RTIs.

Moxifloxacin plus rifampin as an alternative for levofloxacin plus rifampin in the treatment of a prosthetic joint infection with Staphylococcus aureus.

OBJECTIVES: The combination of a fluoroquinolone with rifampin is one of the cornerstones in the treatment of prosthetic joint infections (PJI) caused by staphylococci. Moxifloxacin is highly active against methicillin-susceptible Staphylococcus aureus (MSSA) and, therefore, is an attractive agent to use. However, several studies reported a lowering in serum moxifloxacin levels when combined with rifampin. The clinical relevance remains unclear. We determined the outcome of patients with early acute PJI caused by MSSA treated with either moxifloxacin/rifampin or levofloxacin/rifampin. METHODS: Medical files of patients treated with moxifloxacin/rifampin (University Medical Centre Groningen) or levofloxacin/rifampin (Hospital Clinic Barcelona) were retrospectively reviewed (2005-2015). Treatment failure was defined as the need for revision surgery and/or suppressive therapy, death by infection or a relapse of infection during follow-up. RESULTS: Differences in baseline characteristics between the two cohorts were observed, but prognostic parameters for failure, as defined by the KLIC-score (Kidney failure, Liver cirrhosis, Index surgery, C-reactive protein and Cemented prosthesis), were similar in the two groups (2.9 [1.5 SD] for the moxifloxacin group vs. 2.2 [1.2 SD] for the levofloxacin group [P = 0.16]). With a mean follow-up of 50 months (36 SD) in the moxifloxacin group, and 67 months (50 SD) in the levofloxacin group (P = 0.36), treatment was successful in 89% vs. 87.5%, respectively (P = 0.89). None of the failures in the moxifloxacin group were due to rifampin- or moxifloxacin-resistant S. aureus strains. CONCLUSION: Our data indicate that moxifloxacin combined with rifampin is as clinically effective as levofloxacin/rifampin for early acute PJI caused by MSSA.

Dalbavancin in the treatment of different gram-positive infections: a real-life experience.

Dalbavancin is a lipoglycopeptide with a very prolonged half-life enabling treatment with a single intravenous administration that has been approved to treat complicated skin and soft-tissue infections. Information on the efficacy and safety of dalbavancin in other situations is very scarce. This retrospective study included adult patients who received at least one dose of dalbavancin between 2016 and 2017 in 29 institutions in Spain. The primary objective was to report the use of dalbavancin in clinical practice, including its efficacy and tolerability. The potential impact of dalbavancin on reducing the length of hospital stay and hospital costs was also evaluated. A total of 69 patients received dalbavancin during the study period (58.0% male; median age 63.5 years). Dalbavancin was used to treat prosthetic joint infection (29.0%), acute bacterial skin and skin-structure infection (21.7%), osteomyelitis (17.4%) and catheter-related bacteraemia (11.6%). These infections were mainly caused by Staphylococcus aureus (27 isolates), coagulase-negative staphylococci (24 isolates) and Enterococcus spp. (11 isolates). All but two patients received previous antibiotics for a median of 18 days. Dalbavancin was administered for a median of 21 days (range 7-168 days), and concomitant antimicrobial therapy was prescribed to 25 patients (36.2%). The overall clinical success rate of dalbavancin was 84.1%. Adverse events, mainly mild in intensity, were reported in nine patients. Overall, dalbavancin was estimated to reduce hospitalisation by 1160 days, with an estimated overall cost reduction of €211 481 (€3064 per patient). Dalbavancin appears to be an effective therapy for many serious Gram-positive infections.

The effect of sacral neuromodulation on pregnancy: a systematic review.

INTRODUCTION AND HYPOTHESIS: To evaluate the effects of sacral neuromodulation (SNM) on pregnancy and the impact of delivery on SNM function. METHODS: A systematic search was conducted through January 2016. We selected studies including women who had SNM and a subsequent pregnancy. RESULTS: Out of 2,316, eight studies were included, comprising 22 patients (26 pregnancies). SNM indications were Fowler's syndrome in 11, urinary retention in 6, fecal incontinence in 1, fecal and urinary urgency in 1, overactive bladder in 1, intractable interstitial cystitis in 1, and myelodysplasia in 1. SNM stayed on in 8 pregnancies. In the remaining 18 pregnancies in which the device was deactivated, 7 had recurrent urinary tract infections, including 1 with pyelonephritis and 2 who requested reactivation owing to recurrent symptoms. Outcomes were reported in 25 pregnancies, 16 had Cesarean section (CS) and 9 had vaginal delivery, including 2 operative deliveries. Out of 25, two infants had pilonidal sinus and motor tic disorder (exhibited at the age of 2 years), both from the same mother. After delivery, SNM was functioning in 15 (60%), 4 required reprogramming, and 3 required replacement (1 had recurrence of fecal incontinence after her operative delivery with evidence of displaced leads and 1 patient reported decreased SNM effects after her two CS), and 3 decided to remove the device (2 out of 3 patients were free of symptoms after SNM deactivation and requested removal). CONCLUSION: Within the current limited evidence, the decision regarding SNM activation or deactivation should be individualized. A registry for those patients is recommended.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC).

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

Executive summary of the diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC).

Bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. Optimization of treatment is fundamental in the prognosis of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates have led to research on novel therapeutic schemes. The interest in the new antimicrobials with activity against methicillin-resistant staphylococci has been extended to susceptible strains, which still carry the most important burden of infection. New combinations of antimicrobials have been investigated in experimental and clinical studies, but their role is still being debated. Also, the appropriateness of the initial empirical therapy has acquired relevance in recent years. The aim of this guideline is to update the 2009 guidelines and to provide an ensemble of recommendations in order to improve the treatment of staphylococcal bacteremia and infective endocarditis, in accordance with the latest published evidence.

A propensity score analysis shows that empirical treatment with linezolid does not increase the thirty-day mortality rate in patients with Gram-negative bacteremia.

The role of linezolid in empirical therapy of suspected bacteremia remains unclear. The aim of this study was to evaluate the influence of empirical use of linezolid or glycopeptides in addition to other antibiotics on the 30-day mortality rates in patients with Gram-negative bacteremia. For this purpose, 1,126 patients with Gram-negative bacteremia in the Hospital Clinic of Barcelona from 2000 to 2012 were included in this study. In order to compare the mortality rates between patients who received linezolid or glycopeptides, the propensity scores on baseline variables were used to balance the treatment groups, and both propensity score matching and propensity-adjusted logistic regression were used to compare the 30-day mortality rates between the groups. The overall 30-day mortality rate was 16.0% during the study period. Sixty-eight patients received empirical treatment with linezolid, and 1,058 received glycopeptides. The propensity score matching included 64 patients in each treatment group. After matching, the mortality rates were 14.1% (9/64) in patients who received glycopeptides and 21.9% (14/64) in those who received linezolid, and a nonsignificant association between empirical linezolid treatment and mortality rate (odds ratio [OR], 1.63; 95% confidence interval [CI], 0.69 to 3.82; P = 0.275, McNemar's test) was found. This association remained nonsignificant when variables that remained unbalanced after matching were included in a conditional logistic regression model. Further, the stratified propensity score analysis did not show any significant relationship between empirical linezolid treatment and the mortality rate after adjustment by propensity score quintiles or other variables potentially associated with mortality. In conclusion, the propensity score analysis showed that empirical treatment with linezolid compared with that with glycopeptides was not associated with 30-day mortality rates in patients with Gram-negative bacteremia.

High doses of daptomycin (10 mg/kg/d) plus rifampin for the treatment of staphylococcal prosthetic joint infection managed with implant retention: a comparative study.

We aimed to analyze the efficacy and safety of high doses of daptomycin (10 mg/kg/d) plus rifampin (D10 + R) for prosthetic joint infection (PJI). This was an observational retrospective multicenter study (2010-2012) including all patients with acute PJI by fluoroquinolone-resistant staphylococci managed with implant retention and D10 + R. Twenty cases were included: 2 (10%) were withdrawn due to toxicity, leaving 18 cases for efficacy evaluation: 13 (72%) women, age 79 years (range 58-90). Clinical failure was observed in 9 (50%) patients: in 5 cases, staphylococci were recovered (28% of microbiological failures); no modification of daptomycin-MIC was observed. These 18 cases were compared with 44 matched historical cases: failure rate was similar, but whereas in the historical series, failure occurred fundamentally during therapy, in the present series, it was recorded after discontinuation of antibiotics. In summary, D10 + R may be the initial treatment of choice for PJI by fluoroquinolone-resistant staphylococci managed with implant retention.

Fear of birth defects is a major barrier to soil-transmitted helminth treatment (STH) for pregnant women in the Philippines.

The World Health Organization recommends anthelminthic treatment for pregnant women after the first trimester in soil-transmitted helminth (STH) endemic regions to prevent adverse maternal-fetal consequences. Although studies have shown the high prevalence of infection in the Philippines, no research has evaluated deworming practices. We hypothesized that pregnant women are not receiving deworming treatment and we aimed to identify barriers to World Health Organization guideline implementation. We conducted key informant interviews with local Department of Health (DOH) administrators, focus group discussions with nurses, midwives, and health care workers, and knowledge, attitudes, and practices surveys with women of reproductive age to elicit perspectives about deworming during pregnancy. Key informant interviews revealed that healthcare workers were not deworming pregnant women due to inadequate drug supply, infrastructure and personnel as well as fear of teratogenicity. Focus group discussions showed that healthcare workers similarly had not implemented guidelines due to infrastructure challenges and concerns for fetal malformations. The majority of local women believed that STH treatment causes side effects (74.8%) as well as maternal harm (67.3%) and fetal harm (77.9%). Women who were willing to take anthelminthics while pregnant had significantly greater knowledge as demonstrated by higher Treatment Scores (mean rank 146.92 versus 103.1, z = -4.40, p<0.001) and higher Birth Defect Scores (mean rank 128.09 versus 108.65, z = -2.43, p = 0.015). This study concludes that World Health Organization guidelines are not being implemented in the Philippines. Infrastructure, specific protocols, and education for providers and patients regarding anthelminthic treatment are necessary for the successful prevention of STH morbidity and mortality among pregnant women.

Risk factors for a low linezolid trough plasma concentration in acute infections.

Linezolid is an antibiotic with time-dependent activity, and both the percentage of time that plasma concentrations exceed the MIC and the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC24/MIC ratio) are associated with clinical response. The aim of this study was to analyze the linezolid trough plasma concentration (C(min)) and to determine factors associated with a C(min) < 2 mg/liter and other clinically relevant thresholds. Characteristics of 78 patients receiving 600 mg/12 h of linezolid with a C(min) determination at the steady state and within the first 10 days of treatment were retrospectively reviewed. Concentrations were measured using high-pressure liquid chromatography. Univariate and multivariate analysis were performed to identify risk factors of low C(min). A total of 29.5% of patients had a C(min) < 2 mg/liter. The percentage was significantly higher in patients with an estimated glomerular filtration (eGF) > 80 ml/min, in intensive care unit (ICU) patients, and in patients with an infection due to Staphylococcus aureus. The independent predictors of C(min) < 2 mg/liter were an eGF > 80 ml/min (odds ratio [OR], 10; 95% confidence interval [CI], 2.732 to 37.037; P = 0.001) and infection due to S. aureus (OR, 5.906; 95% CI, 1.651 to 21.126; P = 0.006). A linezolid C(min) of <2 mg/liter was found in 29.5% of cases, and the risk was significantly higher among those with an eGF > 80 ml/min and in infections due to S. aureus. In patients with severe sepsis, a loading dose or continuous infusion and drug monitoring could improve the pharmacodynamic parameters associated with linezolid efficacy.

Previous ciprofloxacin exposure is associated with resistance to beta-lactam antibiotics in subsequent Pseudomonas aeruginosa bacteremic isolates.

BACKGROUND: Pseudomonas aeruginosa cross-resistance to ceftazidime, imipenem, meropenem, piperacillin, and fluoroquinoles has been shown in experimental studies, but information regarding its impact in the clinical setting is scarce and inconsistent. The aim of this study was to assess whether previous exposure to ciprofloxacin influences on the sensitivity of those antibiotics in subsequent P aeruginosa bacteremic isolates. METHODS: Patients with P aeruginosa bacteremia were recorded from a blood culture surveillance program (1997-2007). Demographic characteristics, underlying diseases, setting of the infection, source of infection, previous antibiotic exposure, and antibiotic sensitivity were analyzed. RESULTS: We studied 572 cases of P aeruginosa bacteremia. There were 327 men (57.2%), and the mean age was 61.2 +/- 18 years. The bacteremia was nosocomial in 62.4% of episodes. Resistance rates of P aeruginosa isolates were 15.5% for ceftazidime, 16.7% for imipenem, 11.2% for meropenem, 12.3% for piperacillin-tazobactam, and 23.1% for ciprofloxacin. Exposure to ciprofloxacin during the previous 30 days was an independent predictor of resistance to ceftazidime (odds ratio [OR], 3; 95% confidence interval [CI]: 1.7-5.3; P < .001), imipenem (OR, 2; 95% CI: 1.1-3.7; P = .02), meropenem (OR, 2.7; 95% CI: 1.4-5.3; P = .004), piperacillin-tazobactam (OR, 2.4; 95% CI: 1.3-4.7; P = .007), ciprofloxacin (OR, 2.9; 95% CI: 1.7-4.9; P < .001), and multidrug resistance (OR, 2.5; 95% CI: 1.2-5.2; P = .02). CONCLUSION: P aeruginosa bacteremic isolates from patients who have been exposed to ciprofloxacin during the 30 days prior to the development of bacteremia have an increased risk of being resistant to ceftazidime, imipenem, meropenem, piperacillin-tazobactam, or ciprofloxacin and to have multidrug resistance.

[Consensus document for the treatment of bacteremia and endocarditis caused by methicillin-resistent Staphylococcus aureus. Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica]. / Documento de consenso sobre el tratamiento de la bacteriemia y la endocarditis causada por Staphylococcus aureus resistente a la meticilina. Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica.

Bacteremia and endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and clinically important. The rise in MRSA bacteremia and endocarditis is related with the increasing use of venous catheters and other vascular procedures. Glycopeptides have been the reference drugs for treating these infections. Unfortunately their activity is not completely satisfactory, particularly against MRSA strains with MICs > 1 microg/mL. The development of new antibiotics, such as linezolid and daptomycin, and the promise of future compounds (dalvabancin, ceftobiprole and telavancin) may change the expectatives in this field.The principal aim of this consensus document was to formulate several recommendations to improve the outcome of MRSA bacteremia and endocarditis, based on the latest reported scientific evidence. This document specifically analyzes the approach for three clinical situations: venous catheter-related bacteremia, persistent bacteremia, and infective endocarditis due to MRSA.

Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

BACKGROUND: Vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is not uncommon, even when MRSA is susceptible to vancomycin. The aim of our study was to evaluate whether vancomycin minimum inhibitory concentration has any influence on the mortality associated with MRSA bacteremia. METHODS: A total of 414 episodes of MRSA bacteremia were prospectively followed-up from 1991 through 2005. MIC of vancomycin for the first isolate was determined by E-test. Clinical variables recorded were age, comorbidity, prior administration of vancomycin, use of corticosteroids, prognosis of underlying disease, source of bacteremia, the need for mechanical ventilation, shock, and mortality. A "treatment group" variable was created and defined as follows: (1) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1 microg/mL (38 episodes), (2) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1.5 microg/mL (90 episodes), (3) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (40 episodes), and (4) receipt of inappropriate empirical therapy (246 episodes). Univariate and multivariate analyses were performed. RESULTS: Episodes caused by strains with a vancomycin MIC of 2 microg/mL were independently associated with a lower risk of shock (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.15-0.75). Multivariate analysis selected receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (OR, 6.39; 95% CI, 1.68-24.3), receipt of inappropriate empirical therapy (OR, 3.62; 95% CI, 1.20-10.9), increasing age (OR, 1.02; 95% CI, 1.00-1.04), use of corticosteroids (OR, 1.85; 95% CI, 1.04-3.29), an ultimately (OR, 10.2; 95% CI, 2.85-36.8) or rapidly (OR, 1.81; 95% CI, 1.06-3.10) fatal underlying disease, high-risk (OR, 3.60; 95% CI, 1.89-6.88) and intermediate-risk (OR, 2.18; 95% CI, 1.17-4.04) sources of bacteremia, and shock (OR, 7.38; 95% CI, 4.11-13.3) as the best predictors of mortality. CONCLUSIONS: Mortality associated with MRSA bacteremia was significantly higher when the empirical antibiotic was inappropriate and when vancomycin was empirically used for treatment of infection with strains with a high vancomycin MIC (>1 microg/mL).