Incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infection in European hospitals: the COMBACTE-NET ARTHR-IS multi-centre study.

BACKGROUND: The aim of this study was to estimate the incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infections (SA-PJI) after primary hip and knee arthroplasty in European centres. METHODS: This study was conducted in patients who underwent primary hip and knee arthroplasty in 19 European hospitals between 2014 and 2016. The global incidence of PJI and SA-PJI was calculated. The associated disease burden was measured indirectly as infection-related mortality plus loss of function. For healthcare utilization, number and duration of hospitalizations, number and type of surgical procedures, duration of antibiotic treatments, and number of outpatient visits were collected. Subgroup and regression analyses were used to evaluate the impact of SA-PJI on healthcare utilization, controlling for confounding variables. RESULTS: The incidence of PJI caused by any micro-organism was 1.41%, and 0.40% for SA-PJI. Among SA-PJI, 20.7% were due to MRSA with substantial regional differences, and were more frequent in partial hip arthroplasty (PHA). Related deaths and loss of function occurred in 7.0% and 10.2% of SA-PJI cases, respectively, and were higher in patients with PHA. Compared with patients without PJI, patients with SA-PJI had a mean of 1.4 more readmissions, 25.1 more days of hospitalization, underwent 1.8 more surgical procedures, and had 5.4 more outpatient visits, controlling for confounding variables. Healthcare utilization was higher in patients who failed surgical treatment of SA-PJI. CONCLUSIONS: This study confirmed that the SA-PJI burden is high, especially in PHA, and provided a solid basis for planning interventions to prevent SA-PJI.

[Impact of days elapsed from the onset of symptoms to hospitalization in COVID-19 in-hospital mortality: Time matters]. / Impacto de los días transcurridos desde el inicio de los síntomas hasta la hospitalización en la mortalidad hospitalaria por COVID-19: el tiempo importa.

Background: COVID-19 shows different clinical and pathophysiological stages over time. Theeffect of days elapsed from the onset of symptoms (DEOS) to hospitalization on COVID-19prognostic factors remains uncertain. We analyzed the impact on mortality of DEOS to hospital-ization and how other independent prognostic factors perform when taking this time elapsedinto account. Methods: This retrospective, nationwide cohort study, included patients with confirmed COVID-19 from February 20th and May 6th, 2020. The data was collected in a standardized online datacapture registry. Univariate and multivariate COX-regression were performed in the generalcohort and the final multivariate model was subjected to a sensitivity analysis in an earlypresenting (EP; < 5 DEOS) and late presenting (LP; ≥5 DEOS) group. Results: 7915 COVID-19 patients were included in the analysis, 2324 in the EP and 5591 in theLP group. DEOS to hospitalization was an independent prognostic factor of in-hospital mortalityin the multivariate Cox regression model along with other 9 variables. Each DEOS incrementaccounted for a 4.3% mortality risk reduction (HR 0.957; 95% CI 0.93---0.98). Regarding variationsin other mortality predictors in the sensitivity analysis, the Charlson Comorbidity Index onlyremained significant in the EP group while D-dimer only remained significant in the LP group. Conclusion: When caring for COVID-19 patients, DEOS to hospitalization should be consideredas their need for early hospitalization confers a higher risk of mortality. Different prognosticfactors vary over time and should be studied within a fixed timeframe of the disease.

Impacto de los días transcurridos desde el inicio de los síntomas hasta la hospitalización en la mortalidad hospitalaria por COVID-19: el tiempo importa / Impact of days elapsed from the onset of symptoms to hospitalization in COVID-19 in-hospital mortality: Time matters

Antecedentes La COVID-19 muestra diferentes fases clínicas y fisiopatológicas a lo largo del tiempo. El efecto de los días transcurridos desde el comienzo de los síntomas (DTCS) hasta la hospitalización sobre los factores pronósticos de la COVID-19 sigue siendo incierto. Analizamos el impacto en la mortalidad de los DTCS hasta la hospitalización y cómo se comportan otros factores pronósticos independientes al tener en cuenta dicho tiempo transcurrido. Métodos En este estudio de cohortes nacional retrospectivo se incluyó a pacientes con COVID-19 confirmada entre el 20 de febrero y el 6 de mayo de 2020. Los datos se recopilaron en un registro normalizado de captura de datos en línea. Se realizó una regresión de Cox uni y multifactorial en la cohorte general y el modelo multifactorial final se sometió a un análisis de sensibilidad en un grupo de presentación precoz (PP) < 5 DTCS y otro de presentación tardía (PT) ≥ 5 DTCS). Resultados En el análisis se incluyó a 7.915 pacientes con COVID-19, 2.324 en el grupo de PP y 5.591 en el de PT. Los DTCS hasta la hospitalización fueron un factor pronóstico independiente de mortalidad intrahospitalaria en el modelo de regresión de Cox multifactorial junto con otras nueve variables. Cada incremento en un DTCS supuso una reducción del riesgo de mortalidad del 4,3% (RRI = 0,957; IC 95%, 0,93-0,98). En cuanto a las variaciones de otros factores predictivos de la mortalidad en el análisis de sensibilidad, únicamente el índice de comorbilidad de Charlson siguió siendo significativo en el grupo de PP, mientras que únicamente el dímero D lo siguió siendo en el grupo de PT. Conclusiones Al atender a pacientes con COVID-19 hay que tener en cuenta los DTCS hasta la hospitalización porque la necesidad de hospitalización precoz confiere un mayor riesgo de mortalidad. Los diferentes factores pronósticos varían con el tiempo y deberían estudiarse dentro de un marco temporal fijo de la enfermedad (AU)

Background COVID-19 shows different clinical and pathophysiological stages over time. Theeffect of days elapsed from the onset of symptoms (DEOS) to hospitalization on COVID-19prognostic factors remains uncertain. We analyzed the impact on mortality of DEOS to hospital-ization and how other independent prognostic factors perform when taking this time elapsedinto account. Methods This retrospective, nationwide cohort study, included patients with confirmed COVID-19 from February 20th and May 6th, 2020. The data was collected in a standardized online datacapture registry. Univariate and multivariate COX-regression were performed in the generalcohort and the final multivariate model was subjected to a sensitivity analysis in an earlypresenting (EP; <5 DEOS) and late presenting (LP; ≥5 DEOS) group. Results 7915 COVID-19 patients were included in the analysis, 2324 in the EP and 5591 in theLP group. DEOS to hospitalization was an independent prognostic factor of in-hospital mortalityin the multivariate Cox regression model along with other 9 variables. Each DEOS incrementaccounted for a 4.3% mortality risk reduction (HR 0.957; 95% CI 0.93---0.98). Regarding variationsin other mortality predictors in the sensitivity analysis, the Charlson Comorbidity Index onlyremained significant in the EP group while D-dimer only remained significant in the LP group. Conclusion When caring for COVID-19 patients, DEOS to hospitalization should be consideredas their need for early hospitalization confers a higher risk of mortality. Different prognosticfactors vary over time and should be studied within a fixed timeframe of the disease (AU)

Impact of days elapsed from the onset of symptoms to hospitalization in COVID-19 in-hospital mortality: time matters.

BACKGROUND: COVID-19 shows different clinical and pathophysiological stages over time. The effect of days elapsed from the onset of symptoms (DEOS) to hospitalization on COVID-19 prognostic factors remains uncertain. We analyzed the impact on mortality of DEOS to hospitalization and how other independent prognostic factors perform when taking this time elapsed into account. METHODS: This retrospective, nationwide cohort study, included patients with confirmed COVID-19 from February 20th and May 6th, 2020. The data was collected in a standardized online data capture registry. Univariate and multivariate COX-regression were performed in the general cohort and the final multivariate model was subjected to a sensitivity analysis in an early presenting (EP; <5 DEOS) and late presenting (LP; ≥5 DEOS) group. RESULTS: 7915 COVID-19 patients were included in the analysis, 2324 in the EP and 5591 in the LP group. DEOS to hospitalization was an independent prognostic factor of in-hospital mortality in the multivariate Cox regression model along with other 9 variables. Each DEOS increment accounted for a 4.3% mortality risk reduction (HR 0.957; 95% CI 0.93-0.98). Regarding variations in other mortality predictors in the sensitivity analysis, the Charlson Comorbidity Index only remained significant in the EP group while D-dimer only remained significant in the LP group. CONCLUSION: When caring for COVID-19 patients, DEOS to hospitalization should be considered as their need for early hospitalization confers a higher risk of mortality. Different prognostic factors vary over time and should be studied within a fixed timeframe of the disease.

Antimicrobial resistance in Gram-negative bacilli in Spain: an experts' view.

BACKGROUND: Antibiotic resistance in Gram-negative bacilli poses a serious problem for public health. In hospitals, in addition to high mortality rates, the emergence and spread of resistance to practically all antibiotics restricts therapeutic options against serious and frequent infections. OBJECTIVE: The aim of this work is to present the views of a group of experts on the following aspects regarding resistance to antimicrobial agents in Gram-negative bacilli: 1) the current epidemiology in Spain, 2) how it is related to local clinical practice and 3) new therapies in this area, based on currently available evidence. METHODS: After reviewing the most noteworthy evidence, the most relevant data on these three aspects were presented at a national meeting to 99 experts in infectious diseases, clinical microbiology, internal medicine, intensive care medicine, anaesthesiology and hospital pharmacy. RESULTS AND CONCLUSIONS: Subsequent local debates among these experts led to conclusions in this matter, including the opinion that the approval of new antibiotics makes it necessary to train the specialists involved in order to optimise how they use them and improve health outcomes; microbiology laboratories in hospitals must be available throughout a continuous timetable; all antibiotics must be available when needed and it is necessary to learn to use them correctly; and the Antimicrobial Stewardship Programs (ASP) play a key role in quickly allocating the new antibiotics within the guidelines and ensure appropriate use of them.

The early use of sepsis scores to predict respiratory failure and mortality in non-ICU patients with COVID-19.

This observational retrospective study aimed to investigate the usefulness of Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), National Early Warning Score (NEWS), and quick NEWS in predicting respiratory failure and death among patients with COVID-19 hospitalized outside of intensive care units (ICU). We included 237 adults hospitalized with COVID-19 who were followed-up on for one month or until death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤200mmHg or the need for mechanical ventilation. Respiratory failure occurred in 77 patients (32.5%), 29 patients (12%) were admitted to the ICU, and 49 patients (20.7%) died. Discrimination of respiratory failure was slightly higher in NEWS, followed by SOFA. Regarding mortality, SOFA was more accurate than the other scores. In conclusion, sepsis scores are useful for predicting respiratory failure and mortality in COVID-19 patients. A NEWS score ≥4 was found to be the best cutoff point for predicting respiratory failure.

Utilidad de las escalas de sepsis para predecir el fallo respiratorio y la muerte en pacientes con COVID-19 fuera de las Unidades de Cuidados Intensivos / The early use of sepsis scores to predict respiratory failure and mortality in non-ICU patients with COVID-19

El presente estudio retrospectivo observacional tiene como objetivo analizar la utilidad de las escalas SOFA (Sequential Organ Failure Assessment), qSOFA (Quick SOFA), NEWS (National Early Warning Score ) y Quick NEWS para predecir el fallo respiratorio y la muerte en pacientes con COVID-19 atendidos fuera de la Unidad de Cuidados Intensivos (UCI). Se incluyeron 237 adultos con COVID-19 hospitalizados seguidos durante un mes o hasta su fallecimiento. El fallo respiratorio se definió como un cociente PaO2/FiO2 ≤ 200 mmHg o la necesidad de ventilación mecánica. Setenta y siete pacientes (32,5%) desarrollaron fallo ventilatorio; 29 (12%) precisaron ingreso en UCI, y 49 fallecieron (20,7%). La discriminación del fallo ventilatorio fue algo mayor con la puntuación NEWS, seguida de la SOFA. En cuanto a la mortalidad, la puntuación SOFA fue más exacta que las otras escalas. En conclusión, las escalas de sepsis son útiles para predecir el fallo respiratorio y la muerte en COVID-19. Una puntuación ≥ 4 en la escala NEWS sería el mejor punto de corte para predecir fallo respiratorio (AU)

This observational retrospective study aimed to investigate the usefulness of Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), National Early Warning Score (NEWS), and quick NEWS in predicting respiratory failure and death among patients with COVID-19 hospitalized outside of intensive care units (ICU). We included 237 adults hospitalized with COVID-19 who were followed-up on for one month or until death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤ 200 mmHg or the need for mechanical ventilation. Respiratory failure occurred in 77 patients (32.5%), 29 patients (12%) were admitted to the ICU, and 49 patients (20.7%) died. Discrimination of respiratory failure was slightly higher in NEWS, followed by SOFA. Regarding mortality, SOFA was more accurate than the other scores. In conclusion, sepsis scores are useful for predicting respiratory failure and mortality in COVID-19 patients. A NEWS score ≥ 4 was found to be the best cutoff point for predicting respiratory failure (AU)

[The early use of sepsis scores to predict respiratory failure and mortality in non-ICU patients with COVID-19]. / Utilidad de las escalas de sepsis para predecir el fallo respiratorio y la muerte en pacientes con COVID-19 fuera de las Unidades de Cuidados Intensivos.

This observational retrospective study aimed to investigate the usefulness of Sequential Organ Failure Assessment (SOFA), Quick SOFA (qSOFA), National Early Warning Score (NEWS), and quick NEWS in predicting respiratory failure and death among patients with COVID-19 hospitalized outside of intensive care units (ICU). We included 237 adults hospitalized with COVID-19 who were followed-up on for one month or until death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤ 200 mmHg or the need for mechanical ventilation. Respiratory failure occurred in 77 patients (32.5%), 29 patients (12%) were admitted to the ICU, and 49 patients (20.7%) died. Discrimination of respiratory failure was slightly higher in NEWS, followed by SOFA. Regarding mortality, SOFA was more accurate than the other scores. In conclusion, sepsis scores are useful for predicting respiratory failure and mortality in COVID-19 patients. A NEWS score ≥ 4 was found to be the best cutoff point for predicting respiratory failure.

Staphylococcus aureus native arthritis over 10 years.

OBJECTIVES: Septic arthritis is associated with significant case fatality and morbidity. Staphylococcus aureus is the most common cause of arthritis. We aimed to analyze the microbiological features of S. aureus causing native arthritis and to investigate their influence on the clinical outcome of the infection. PATIENTS AND METHODS: We conducted a retrospective study including all episodes of S. aureus native arthritis between 2005-2015. Phenotypic (antimicrobial susceptibility, ß-hemolysis, agr functionality, biofilm formation) and genotypic characteristics (pulsed-field gel electrophoresis, DNA microarrays) were investigated. The primary endpoint was microbiological failure of treatment, including infection relapse, persistence, or attributable death. RESULTS: Twenty-nine patients were included (65.5% of men, mean age: 59): seven (24.1%) patients presenting with methicillin-resistant S. aureus (MRSA) native arthritis and 19 with methicillin-susceptible S. aureus (MSSA) native arthritis. Treatment failure occurred in seven (26.9%) patients (4/7 patients [57.1%] among MRSA infections vs. 3/19 [15.8%] among MSSA infections). The persistence rate was similar in MRSA and MSSA infections (1/7 vs. 3/19). However, the case fatality was significantly higher in patients with MRSA infection (3/7 vs. 0/19). The most frequent clonal complex (CC) was CC5 (38.1%). MSSA showed higher genetic variability (nine CCs) versus MRSA (3 CCs). CONCLUSIONS: Beyond methicillin resistance, we did not find phenotypic or genotypic factors associated with the poor outcome of S. aureus native arthritis. CC5 was the major CC, showing the higher genetic variability of MSSA versus MRSA.

Safety and Efficacy of Prolonged Use of Dalbavancin in Bone and Joint Infections.

Dalbavancin is a lipoglycopeptide with potent activity against Gram-positive microorganisms, a long half-life, a favorable safety profile, and a high concentration in bone, which makes it an interesting alternative for treatment of osteoarticular infections. We performed a multicentric retrospective study of all patients with an osteoarticular infection (septic arthritis, spondylodiscitis, osteomyelitis, or orthopedic implant-related infection) treated with at least one dose of dalbavancin between 2016 and 2017 in 30 institutions in Spain. In order to evaluate the response, patients with or without an orthopedic implant were separated. A total of 64 patients were included. Staphylococcus epidermidis and Staphylococcus aureus were the most frequent microorganisms. The reasons for switching to dalbavancin were simplification (53.1%), adverse events (25%), or failure (21.9%). There were 7 adverse events, and no patient had to discontinue dalbavancin. In 45 cases, infection was related to an orthopedic implant. The implant material was retained in 23 cases, including that in 15 (65.2%) patients that were classified as cured and 8 (34.8%) that presented improvement. In 21 cases, the implants were removed, including those in 16 (76.2%) cases that were considered successes, 4 (19%) cases were considered improved, and 1 (4.8%) case that was considered a failure. Among the 19 cases without implants, 14 (73.7%) were considered cured, 3 (15.8%) were considered improved, and 2 (10.5%) were considered failures. The results show that dalbavancin is a well-tolerated antibiotic, even when >2 doses are administered, and is associated with a high cure rate. These are preliminary data with a short follow-up; therefore, it is necessary to gain more experience and, in the future, to establish the most appropriate dose and frequency.

Staphylococcus aureus meningitis in adults: A comparative cohort study of infections caused by meticillin-resistant and meticillin-susceptible strains.

BACKGROUND: Staphylococcus aureus meningitis is an uncommon nosocomial infection usually associated with neurosurgical procedures, but spontaneous infections may occasionally appear. AIMS: To compare the features of meningitis caused by meticillin-resistant (MRSA) and meticillin-susceptible (MSSA) S. aureus and examine the prognostic factors for mortality, including MRSA infection and combined antimicrobial therapy. METHODS: Retrospective cohort study of 350 adults with S. aureus meningitis admitted to 11 hospitals in Spain (1981-2015). Logistic regression and propensity score matching were used to analyse prognostic factors. RESULTS: There were 118 patients (34%) with MRSA and 232 (66%) with MSSA. Postoperative infection (91% vs 73%) and nosocomial acquisition (93% vs 74%) were significantly more frequent in MRSA than in MSSA meningitis (P < 0.001). Combined therapy was given to 118 (34%) patients. Overall 30-day mortality rate was 23%. On multivariate analysis, mortality was associated with severe sepsis or shock (odds ratio (OR) 9.9, 95% confidence interval (CI) 4.5-22.0, P < 0.001), spontaneous meningitis (OR 4.2, 95% CI 1.9-9.1, P < 0.001), McCabe-Jackson score rapidly or ultimately fatal (OR 2.8, 95% CI 1.4-5.4, P = 0.002), MRSA infection (OR 2.6, 95% CI 1.3-5.3, P = 0.006), and coma (OR 2.6, 95% CI 1.1-6.1, P < 0.029). In postoperative cases, mortality was related to retention of cerebrospinal devices (OR 7.9, 95% CI 3.1-20.3, P < 0.001). CONCLUSIONS: Clinical and epidemiological differences between MRSA and MSSA meningitis may be explained by the different pathogenesis of postoperative and spontaneous infection. In addition to the severity of meningitis and underlying diseases, MRSA infection was associated with increased mortality. Combined antimicrobial therapy was not associated with increased survival.

Outcome of patients with streptococcal prosthetic joint infections with special reference to rifampicin combinations.

BACKGROUND: Outcome of patients with streptococcal prosthetic joint infections (PJIs) is not well known. METHODS: We performed a retrospective multicenter cohort study that involved patients with total hip/knee prosthetic joint (THP/TKP) infections due to Streptococcus spp. from 2001 through 2009. RESULTS: Ninety-five streptococcal PJI episodes (50 THP and 45 TKP) in 87 patients of mean age 69.1 ± 13.7 years met the inclusion criteria. In all, 55 out of 95 cases (57.9 %) were treated with debridement and retention of the infected implants with antibiotic therapy (DAIR). Rifampicin-combinations, including with levofloxacin, were used in 52 (54.7 %) and 28 (29.5 %) cases, respectively. After a mean follow-up period of 895 days (IQR: 395-1649), the remission rate was 70.5 % (67/95). Patients with PJIs due to S. agalactiae failed in the same proportion as in the other patients (10/37 (27.1 %) versus 19/58 (32.7 %); p = .55). In the univariate analysis, antibiotic monotherapy, DAIR, antibiotic treatments other than rifampicin-combinations, and TKP were all associated with a worse outcome. The only independent variable significantly associated with the patients' outcomes was the location of the prosthesis (i.e., hip versus knee) (OR = 0.19; 95 % CI 0.04-0.93; p value 0.04). CONCLUSIONS: The prognosis of streptococcal PJIs may not be as good as previously reported, especially for patients with an infected total knee arthroplasty. Rifampicin combinations, especially with levofloxacin, appear to be suitable antibiotic regimens for these patients.

Significance of the isolation of Staphylococcus aureus from a central venous catheter tip in the absence of concomitant bacteremia: a clinical approach.

The optimal approach following the isolation of Staphylococcus aureus from an intravascular catheter tip in the absence of concomitant bacteremia remains unclear. We aimed to determine the rate of delayed complications in these patients. We performed a retrospective observational study (during the period 2002-2012) including patients with a catheter tip culture yielding S. aureus. Patients were followed up for ≥6 months. The primary endpoint was the occurrence of delayed staphylococcal complications (either bacteremia and/or metastatic distant infections). A total of 113 patients were included (75 % male, median age 61 years): 46 and 67 with negative and positive blood cultures, respectively. We found a lower rate of delayed staphylococcal complications in cases with no bacteremia within 48 h since catheter removal than in cases of confirmed S. aureus catheter-related bacteremia (0.0 % vs. 25.4 %; p-value < 0.001). In the group without bacteremia, there was a subgroup of 15 patients (32.6 %) who did not receive antimicrobial treatment. Again, delayed complications occurred less commonly in this subgroup of patients without bacteremia (0.0 % vs. 25.4 %; p-value = 0.033). In contrast to patients with S. aureus catheter-related bacteremia, no delayed infectious complications were observed in patients with an isolated catheter tip culture yielding S. aureus and negative blood cultures within 48 h of catheter removal. Futures studies are needed to assess if the therapeutic approach could be different for this group of patients.

Risk factors for metastatic osteoarticular infections after a long follow-up of patients with Staphylococcus aureus bacteraemia.

We aimed to identify risk factors associated with the development of haematogenous metastatic osteoarticular infection (MOI) after an episode of Staphylococcus aureus bacteraemia (SAB). We followed 198 patients with SAB during a median of 68.9 months. Nine (4.54%) developed an MOI (median: 6.77 months) after SAB. Factors associated with MOI were the presence of joint prosthesis (hazard ratio 17.56; 95% CI 4.48-68.85) and osteoporosis (hazard ratio 8.46; 95% CI 1.9-37.57). MOI is a common complication after SAB and is related to high morbidity and mortality. Patients with previous osteoarticular disease are at the greatest risk of developing this complication.

The changing epidemiology of bacteraemic osteoarticular infections in the early 21st century.

Osteoarticular infections (OAI), which are often associated with bacteraemia, seem to be increasing. We studied all patients with bacteraemia and concomitant OAI: septic arthritis (SA), vertebral osteomyelitis (VOM) or peripheral osteomyelitis (POM), which were seen at our institution (1985-2011). Data were extracted from a prospective protocol of bacteraemia cases recorded. Trends in main findings were considered in five periods. Major antibiotic resistance patterns were studied. A total of 601 cases of bacteraemic OAI, accounting for 1.8% of total bactaeremias, were studied: SA (48%), VOM (40%) and POM (17%). When comparing the 1985-91 and 2007-11 periods, the incidence of bacteraemic OAI increased from 2.34 to 5.78 episodes/100 000 inhabitants per year (p <0.001); and nosocomial and healthcare-related cases increased from 18% to 30% (p <0.001) and from 10% to 25% (p <0.001), respectively. Also, there was an increase of age (median, from 49 to 65 years, p <0.001), patients with comorbidities (23% to 59%, p <0.001), and device-related OAI (7% to 28%, p <0.001). Patterns of OAI were changing over time. Compared with younger patients, older adults (≥ 65 years) had more VOM, prosthetic-joint infections and enterococcal OAI. The percentage of OAI caused by methicillin-susceptible Staphylococcus aureus decreased, while those caused by methicillin-resistant S. aureus, streptococci, enterococci, and Gram-negative bacilli increased. There was a link between certain microorganisms with specific OAI and age of patients. Over the past three decades, bacteraemic OAI increased in association with aging and use of orthopaedic devices. Nosocomial and healthcare-related OAI increased, with a rise in multidrug-resistant bacteria. These trends should be considered when planning diagnostic and therapeutic guidelines for OAI.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study.

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

Streptococcal vertebral osteomyelitis: multiple faces of the same disease.

The role of Streptococcus species as an aetiological microorganism of vertebral osteomyelitis (VO) is considered to be of little relevance. We aimed to describe a large number of cases of streptococcal vertebral osteomyelitis (SVO), to analyze the clinical features associated with different Streptococcus species, and to compare them with a cohort of patients with VO caused by Staphylococcus aureus. An incidence study and a retrospective, multicenter, observational clinical study of cases of SVO (1991-2011) were performed. Statistical comparison of SVO by different species and between them and staphylococcal VO was carried out. Over the whole period there was an increasing incidence in the number of VOs and SVOs per year (p <0.05). Among 58 cases of SVO, those caused by non-viridans streptococcus (Streptococcus pneumoniae, Streptococcus agalactiae and Streptococcus pyogenes; n = 26) mimicked VO by S. aureus, and presented with more fever, neurological symptoms and paravertebral abscesses in comparison with those caused by the viridans group (remaining species). In contrast, the latter have a sub-acute clinical picture and were associated with the presence of endocarditis (p <0.05). Among non-viridans SVOs, concomitant infection was specifically related to S. pneumoniae (p <0.05). In conclusion, SVO presents a wide range of clinical patterns. The relationship between VO and diagnosis of endocarditis was established with SVO caused by the viridans group. Whereas non-viridans SVO mimics acute characteristics of VO caused by S. aureus, cases of viridans SVO are significantly more likely to have a sub-acute clinical presentation. The increased incidence of SVO during the last decades could support a new epidemiological scenario.

Fosfomycin-daptomycin and other fosfomycin combinations as alternative therapies in experimental foreign-body infection by methicillin-resistant Staphylococcus aureus.

The efficacy of daptomycin, imipenem, or rifampin with fosfomycin was evaluated and compared with that of daptomycin-rifampin in a tissue cage model infection caused by methicillin-resistant Staphylococcus aureus (MRSA). Strain HUSA 304 was used. The study yielded the following results for MICs (in µg/ml): fosfomycin, 4; daptomycin, 1; imipenem, 0.25; and rifampin, 0.03. The study yielded the following results for minimum bactericidal concentration (MBC) (in µg/ml): fosfomycin, 8; daptomycin, 4; imipenem, 32; and rifampin, 0.5. Daptomycin-rifampin was confirmed as the most effective therapy against MRSA foreign-body infections. Fosfomycin combinations with high doses of daptomycin and rifampin were efficacious alternative therapies in this setting. Fosfomycin-imipenem was relatively ineffective and did not protect against resistance.

Efficacy of daptomycin-cloxacillin combination in experimental foreign-body infection due to methicillin-resistant Staphylococcus aureus.

Despite the use of daptomycin alone at high doses (greater than 6 mg/kg of body weight/day) against difficult-to-treat infections, clinical failures and resistance appeared. Recently, the combination daptomycin-cloxacillin showed enhanced efficacy in clearing bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to evaluate the efficacy of daptomycin at usual and high doses (equivalent to 6 and 10 mg/kg/day in humans, respectively) in combination with cloxacillin in a rat tissue cage infection model by MRSA and to compare its efficacy to that of daptomycin-rifampin. We used MRSA strain ATCC BAA-39. In the log- and stationary-phase kill curves, daptomycin-cloxacillin improved the bactericidal activity of daptomycin, especially in log phase. For in vivo studies, therapy was administered intraperitoneally for 7 days with daptomycin at 100 mg/kg/day and 45/mg/kg/day (daptomycin 100 and daptomycin 45), daptomycin 100-cloxacillin at 200 mg/kg/12 h, daptomycin 45-cloxacillin, and daptomycin 100-rifampin at 25 mg/kg/12 h. Daptomycin-rifampin was the best therapy (P < 0.05). Daptomycin 45 was the least effective treatment and did not protect against the emergence of resistant strains. There were no differences between the two dosages of daptomycin plus cloxacillin in any situation, and both protected against resistance. The overall effect of the addition of cloxacillin to daptomycin was a significantly greater cure rate (against adhered bacteria) than that for daptomycin alone. In conclusion, daptomycin-cloxacillin enhanced modestly the in vivo efficacy of daptomycin alone against foreign-body infection by MRSA and was less effective than daptomycin plus rifampin. The benefits of adding cloxacillin to daptomycin should be especially evaluated against infections by rifampin-resistant MRSA and for protection against the emergence of daptomycin nonsusceptibility.