Post-surgical mediastinitis due to carbapenem-resistant Enterobacteriaceae: Clinical, epidemiological and survival characteristics.

Invasive infections due to carbapenem-resistant Enterobacteriaceae (CRE), including polymyxin-resistant (PR-CRE) strains, are being increasingly reported. However, there is a lack of clinical data for several life-threatening infections. Here we describe a cohort of patients with post-surgical mediastinitis due to CRE, including PR-CRE. This study was a retrospective cohort design at a single cardiology centre. Patients with mediastinitis due to CRE were identified and were investigated for clinically relevant variables. Infecting isolates were studied using molecular techniques. Patients infected with polymyxin-susceptible CRE (PS-CRE) strains were compared with those infected with PR-CRE strains. In total, 33 patients with CRE mediastinitis were studied, including 15 patients (45%) with PR-CRE. The majority (61%) were previously colonised. All infecting isolates carried blaKPC genes. Baseline characteristics of patients with PR-CRE mediastinitis were comparable with those with PS-CRE mediastinitis. Of the patients studied, 70% received at least one agent considered active in vitro and most patients received at least three concomitant antibiotics. Carbapenem plus polymyxin B was the most common antibiotic combination (73%). Over 90% of patients underwent surgical debridement. Overall, in-hospital mortality was 33% and tended to be higher in patients infected with PR-CRE (17% vs. 53%; P=0.06). In conclusion, mediastinitis due to CRE, including PR-CRE, can become a significant challenge in centres with CRE and a high cardiac surgery volume. Despite complex antibiotic treatments and aggressive surgical procedures, these patients have a high mortality, particularly those infected with PR-CRE.

Analysis of Phase 3 telavancin nosocomial pneumonia data excluding patients with severe renal impairment and acute renal failure.

OBJECTIVES: Telavancin is approved in Europe for the treatment of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus when other alternatives are not suitable. The approved European prescribing information contraindicates the use of telavancin in patients with severe renal impairment (creatinine clearance <30 mL/min, including patients on haemodialysis) and pre-existing acute renal failure owing to the higher observed mortality in these patients. Data from the ATTAIN studies were reanalysed, excluding patients with these contraindicating conditions at baseline. (At the time of submission of this article, the European marketing authorization of telavancin for the treatment of nosocomial pneumonia was suspended pending evidence of a new European Medicines Agency-approved supplier. Clinigen Healthcare Ltd, Theravance's commercialization partner for telavancin in Europe, is in the process of seeking approval of a new manufacturing source.) METHODS: A post hoc analysis of data from two Phase 3 ATTAIN trials of telavancin for the treatment of Gram-positive nosocomial pneumonia assessing clinical outcomes and safety. RESULTS: The all-treated population for this analysis represented 84.2% (1266/1503) of the ATTAIN all-treated population. The cure rates in the clinically evaluable population were similar in the telavancin (82.5%, 231/280) and vancomycin (81.3%, 243/299) groups [treatment difference (95% CI): 1.3% (-5.0% to 7.6%)], and were consistent with the overall ATTAIN study results. The cure rate was higher in the telavancin than the vancomycin treatment group in microbiologically evaluable patients with only Gram-positive pathogens isolated at baseline [85.0% (130/153) versus 75.2% (109/145), respectively; treatment difference (95% CI): 9.7% (0.6%-18.8%)]. The incidences of adverse events were similar between treatment groups and consistent with the overall findings of the ATTAIN study. CONCLUSIONS: This analysis demonstrated that in the subset of patients without severe renal impairment or pre-existing acute renal failure, clinical and safety outcomes were similar in the telavancin and vancomycin treatment groups.

Methicillin-resistant Staphylococcus aureus ST30-SCCmec IVc clone as the major cause of community-acquired invasive infections in Argentina.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have become a major concern worldwide. We conducted a prospective multicenter study of invasive CA-MRSA to evaluate clinical features and genotype of strains causing invasive infections in Argentina. A total of 55 patients with invasive CA-MRSA infections were included. Most patients (60%) had bloodstream infections, 42% required admission to intensive care unit and 16% died. No CA-MRSA isolates were multiresistant (resistant ⩾3 classes of antibiotics). All isolates carried Panton-Valentine leukocidin (PVL) genes and staphylococcal cassette chromosome (SCCmec) type IV. The majority CA-MRSA strains belonged to ST30 and had identical pulsed-field gel electrophoresis (PFGE) patterns, qualifying as a clonal dissemination of a highly transmissible strain. The main clone recovered from patients with CA-MRSA invasive infections was genotyped as pulsed-field gel electrophoresis type C-ST30, SCCmec type IVc-spa type 019, PVL positive. It has become predominant and replaced the previously described CA-MRSA clone (PFGE type A, ST5, SCCmec type IV, spa type 311).

Accuracy of weight and height estimation in an intensive care unit.

We report the findings from a prospective study determining the magnitude of errors in the visual estimation of weight and height of critically ill patients. Forty-two consecutive patients were weighed by a physician with a calibrated stretcher scale and length measured with a steel measuring tape. The predicted body weight was calculated using the ARDSnet formulae. Attending physicians and nurses were asked to estimate patient's actual weight, predicted weight and height. The average percent errors in estimation of actual and predicted weight were 11.4 and 14.6%, respectively. Errors greater than 20% in patient's actual and predicted weight were observed in 15 and 24% of cases, respectively. The majority of height estimations (86%) had an error < 10%. There were non-significant differences between the estimations made by intensive care unit physicians and nurses. Our study shows that estimations of patient's weight made by intensive care unit staff are often inaccurate. In contrast, estimations of height made by intensive care unit staff are usually adequate. Estimated body weight of critically ill patients has implications for drug and respiratory therapy and should be used with caution.

Association of SLC11A1 with tuberculosis and interactions with NOS2A and TLR2 in African-Americans and Caucasians.

SETTING: Host defense factors may influence the development of active tuberculosis (TB). OBJECTIVE: To test variants in solute carrier family 11A, member 1 (SLC11A1), for an association with TB. METHODS: A mixed case-control study of TB cases, relatives or close contact controls, consisting of 474 African-Americans (243 families) and 381 Caucasians (192 families), examined 13 SLC11A1 polymorphisms for association with pulmonary TB using generalized estimating equations adjusting for age and sex. RESULTS: Two associations were observed in Caucasians (rs3731863, P = 0.03, and rs17221959, P = 0.04) and one in African-Americans (rs3731865, P = 0.05). Multilocus analyses between polymorphisms in SLC11A1 and 11 TB candidate genes detected interactions between SLC11A1 and inducible nitric oxide synthase (NOS2A) in Caucasians (rs3731863 [SLC11A1] x rs8073782 [NOS2A], P = 0.009; rs3731863 [SLC11A1] x rs17722851 [NOS2A], P = 0.007) and toll-like receptor 2 (TLR2) in African-Americans (rs3731865 [SLC11A1] x rs1816702, P = 0.005). CONCLUSIONS: No association was detected with 5'(GT)(n) promoter polymorphism previously associated with lower SLC11A1 expression, rs17235409 (D543N), or rs17235416 (3' TGTG insertion/deletion polymorphism). SLC11A1 polymorphism rs3731865 was associated with TB in African-Americans, consistent with previous findings in West Africans. These results suggest that variants in SLC11A1 increase susceptibility to pulmonary TB and interact with other variants that differ by race.

Coagulase-negative staphylococcal prosthetic valve endocarditis--a contemporary update based on the International Collaboration on Endocarditis: prospective cohort study.

OBJECTIVE: To describe the contemporary features of coagulase-negative staphylococcal (CoNS) prosthetic valve endocarditis (PVE). DESIGN: Observational study of prospectively collected data from a multinational cohort of patients with infective endocarditis. Patients with CoNS PVE were compared to patients with Staphylococcus aureus and viridans streptococcal (VGS) PVE. SETTING: The International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS) is a contemporary cohort of patients with infective endocarditis from 61 centres in 28 countries. PATIENTS: Adult patients in the ICE-PCS with definite PVE and no history of injecting drug use from June 2000 to August 2005 were included. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Heart failure, intracardiac abscess, death. RESULTS: CoNS caused 16% (n = 86) of 537 cases of definite non-injecting drug use-associated PVE. Nearly one-half (n = 33/69, 48%) of patients with CoNS PVE presented between 60 days and 365 days of valve implantation. The rate of intracardiac abscess was significantly higher in patients with CoNS PVE (38%) than in patients with either S aureus (23%, p = 0.03) or VGS (20%, p = 0.05) PVE. The rate of abscess was particularly high in early (50%) and intermediate (52%) CoNS PVE. In-hospital mortality was 24% for CoNS PVE, 36% for S aureus PVE (p = 0.09) and 9.1% for VGS PVE (p = 0.08). Meticillin resistance was present in 68% of CoNS strains. CONCLUSIONS: Nearly one-half of CoNS PVE cases occur between 60 days and 365 days of prosthetic valve implantation. CoNS PVE is associated with a high rate of meticillin resistance and significant valvular complications.