Outbreak of postoperative empyema caused by Serratia marcescens in a thoracic surgery unit.

An increase in the number of cases of postoperative empyema due to S. marcescens was recognized in the intensive care unit (ICU) of our Division of Thoracic Surgery between 3 and 19 March 2013. Pleural samples from patients and environmental samples from the operating room and ICU were obtained. A total of eight isolates (six from pleural fluid and two from portable suction devices in ICU) were identified as Serratia marcescens. All isolates were found to be identical by repetitive sequence-based polymerase chain reaction. This is the first report of an outbreak caused by S. marcescens related to a contaminated portable suction machine.

Exposure to anthrax toxin alters human leucocyte expression of anthrax toxin receptor 1.

Anthrax is a toxin-mediated disease, the lethal effects of which are initiated by the binding of protective antigen (PA) with one of three reported cell surface toxin receptors (ANTXR). Receptor binding has been shown to influence host susceptibility to the toxins. Despite this crucial role for ANTXR in the outcome of disease, and the reported immunomodulatory consequence of the anthrax toxins during infection, little is known about ANTXR expression on human leucocytes. We characterized the expression levels of ANTXR1 (TEM8) on human leucocytes using flow cytometry. In order to assess the effect of prior toxin exposure on ANTXR1 expression levels, leucocytes from individuals with no known exposure, those exposed to toxin through vaccination and convalescent individuals were analysed. Donors could be defined as either 'low' or 'high' expressers based on the percentage of ANTXR1-positive monocytes detected. Previous exposure to toxins appears to modulate ANTXR1 expression, exposure through active infection being associated with lower receptor expression. A significant correlation between low receptor expression and high anthrax toxin-specific interferon (IFN)-γ responses was observed in previously infected individuals. We propose that there is an attenuation of ANTXR1 expression post-infection which may be a protective mechanism that has evolved to prevent reinfection.

Naturally occurring cutaneous anthrax: antibiotic treatment and outcome.

OBJECTIVES: Cutaneous anthrax (CA) is the most common clinical presentation in human anthrax, but the duration of antibiotic therapy in naturally occurring CA is controversial. The aim of this study was to compare the clinical outcomes of patients receiving antibiotic treatment for either 3-5 days (group 1) or 7-10 days (group 2) in uncomplicated CA. METHODS: A total of 66 patients were enrolled; 29 (44%) in group 1 and 37 (56%) in group 2. Infections were classified as mild (n = 22, 33%) or severe (n = 44, 67%) CA. RESULTS: There were no significant differences between the groups in symptom resolution time, fever clearance time, healing of lesions, development and healing of eschars, requirement for surgical intervention or the development of complications. Both edema resolution time and duration of hospital stay were longer in group 2. There were no therapeutic failures, relapses or deaths in either group. Steroid therapy was used in 32% of patients with severe CA, but a beneficial effect on resolution of edema was not demonstrated. CONCLUSIONS: These results suggest that short-course antibiotic therapy is as effective as standard-duration therapy in uncomplicated CA and that steroid therapy may not be effective.

A forgotten diagnosis in emergency department: tetanus.

INTRODUCTION: Tetanus is a serious and acute life-threatening disease caused by toxins of "Clostridium tetani". Although it is generally a disease of developing countries, its lower incidence is encountered also in developed countries. Since the principal treatment of this disease is known to be based on vaccination and wound care, the emergency physicians play a key role in its management. MATERIAL AND METHOD: In the present study, we reviewed its uncommon clinical course along with demographic and clinical features of five cases that have presented with various complaints to our Emergency Department. Presenting signs, demographic features, injury history, and the time from the occurrence of injury to the beginning of symptoms were evaluated. RESULTS: Four of five cases were female. The mean age of cases was 56.8 (34-73). Three of them had hand injury, one had foot injury, and the fifth case had facial injury. The initial symptoms included difficult jaw movement, back muscle spasm, and pain. Two cases died. CONCLUSION: Tetanus cases may present to ED with different symptoms. Therefore, physicians should be aware of the early signs of tetanus. Careful and meticulous wound management of cases presented to ED following an injury should be considered a significant factor, which can help in reducing the tetanus cases (Tab. 2, Ref. 18).

Clinical experience with tigecycline in the treatment of carbapenem-resistant Acinetobacter infections.

Tigecycline is a promising therapeutic option against many current multidrug resistant pathogens. The aim of this retrospective study was to determine the clinical and microbiological outcomes of patients treated with tigecycline for serious infections caused by carbapenem-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii complex (Acb-complex). A retrospective study was conducted to define the patients who received tigecycline for carbapenem-resistant Acb-complex infections between 1 June, 2008 and 1 may, 2009. A total of 21 patients were eligible for the study. The median age of the patients was 48 years and 6 patients were female. Eighteen patients were treated with tigecycline for carbapenemresistant Acb-complex as the sole microorganism while 3 received it for polymicrobial infections. All Acb-complex isolates were susceptible to tigecycline. The most common indication of tigecycline treatment was surgical-site infections (SSI) followed by ventilator associated pneumonia (VAP). Tigecycline was the sole antibiotic administered in 7 patients while concurrent antibiotics were used in 14 patients. The median duration of tigecycline therapy was 14 days. Two patients died within 14 days of initiating treatment, representing an attributable mortality rate of 9.5% while 4 patients died within 30 days representing a crude mortality rate of 19.1%. Seventeen out of 21 patients had successful clinical outcomes, cure in 11 patients and improvement in 6. Fourteen of 21 patients had microbiological failure. Correlation between microbiological response with clinical outcome was poor. Clinical failure was more common in patients with VAP. Patients with bacteremia were more likely to have microbiological failure while microbiological outcome was better in patients with SSI. In this retrospective study, 81% (17 of 21) of the patients infected with carbapenem-resistant Acb-complex had a positive outcome under tigecycline therapy. However, these preliminary results should be evaluated cautiously in the absence of well-controlled studies.

The interaction between piperacillin/tazobactam and assays for Aspergillus galactomannan and 1,3-beta-D-glucan in patients without risk factors for invasive fungal infections.

BACKGROUND: The aim of this study was to investigate the interaction between intravenous piperacillin/tazobactam treatment and Aspergillus galactomannan antigen (GM) and 1,3-beta-D: -glucan (BDG) test results in patients without known risk factors for invasive fungal infections (IFI). PATIENTS AND METHODS: Patients without known risk factors for IFI and who were to receive piperacillin/tazobactam monotherapy were considered eligible for the study. Serum samples were obtained both before and after antibiotic infusion on the first, third, seventh and tenth days of a piperacillin/tazobactam treatment course and 4 days after the last dose. GM was determined by Platelia Aspergillus ELISA (Bio-Rad Laboratories) and BDG was assayed using the Fungitell kit (Associates of Cape Cod, East Falmouth, MA) according to manufacturers' specifications. RESULTS: A total of 135 serum samples were collected from 15 patients. When a cut-off level of >or=0.7 was used for GM positivity, there were no false positive results. When a cut-off level of >or=0.5 was used, six serum samples were positive. There were no statistically significant differences between the median GM indices or median BDG levels of the various sampling times. However, 24 of 135 serum samples were positive for BDG for a threshold of 80 pg/mL. After ruling out fungal infections and all known potential causes of false BDG positivity, environmental contamination remained a possible cause of BDG reactivity. CONCLUSION: No significant interaction was observed between piperacillin/tazobactam administration and Aspergillus GM and BDG assays. Positive results for these tests should be evaluated cautiously in patients at high risk for IFI receiving piperacillin/tazobactam.

Rapid detection of antibacterial resistance in emerging Gram-positive cocci.

Effective infection control efforts obviously depend on the performance of the laboratory to detect emerging resistant pathogens accurately and confirm resistance patterns by additional methods to conventional or automated systems. Conventional methods still remain the predominant approaches for detection and identification of bacteria and resistance patterns. However, the estimated time for conventional tests to detect resistance is at least 24-48 h for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and other epidemiologically important pathogens. Most of the tests used for rapid detection require bacterial growth in culture. There is an important clinical need for rapid detection of bacteria directly from patient samples. Rapid methods based on immunological or molecular technologies have contributed significantly. Molecular assays for several resistance markers are reliable, such as for mecA in staphylococci and vanA in enterococci. However, for other resistance markers, there is a lack of field testing. Cost-effectiveness of rapid detection of antibacterial resistance is another concern. Molecular assays would be useful for tertiary hospitals considering the investment costs and requirement of expert laboratory staff. For smaller centres, rapid tests based on immunological techniques may be a better choice.