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Bacteriocins are low molecular peptides with antimicrobial activity, which are of great interest as food bio-preservatives and for treating diseases caused by pathogenic bacteria. In this study, we present the characterization of bacteriocins produced by Lactobacillus plantarum LE5 and LE27 isolated from ensiled corn. Bacteriocins were purified through ammonium sulfate precipitation and double dialysis by using 12- and 1-kDa membranes. Bacteriocins showed activity against Listeria innocua, Listeria monocytogenes, and Enteroccocus faecalis. Molecular weight was estimated through Tricine-SDS-PAGE and overloading the gel onto Mueller-Hinton agar seeded with L. monocytogenes, showing an inhibition zone between 5 and 10 kDa. NanoLC-MS/MS analysis allowed the identification of UPF0291 protein (UniProtKB/Swiss-Prot Q88VI7), which is also presented in other lactic acid bacteria without assigned function. Ab initio modeling showed it has an α-helix-rich structure and a large positive-charged region. Bacteriocins were stable between 4 and 121 °C and pH 2 and 12, and the activity was inhibited by SDS and proteases. Mode of action assay suggests that the bacteriocin causes of target microorganism. Taken together, these results describe a possible new class IIa bacteriocin produced by L. plantarum, which has a wide stability to physicochemical conditions, and that could be used as an alternative for the control of foodborne diseases.

Background: Tracheostomy is a commonly performed procedure in ventilator dependent patients. Many critical care practitioners believe that performing a tracheostomy early in the postinjury period decreases the length of ventilator dependence as well as having other benefits such as better patient tolerance and lower respiratory dead space. We conducted a randomized, prospective, single institution study comparing the length ventilator dependence in critically ill multiple trauma patients who were randomized to two different strategies for performance of a tracheostomy. We hypothesized that earlier tracheostomy would reduce the number of days of mechanical ventilation, frequency of pneumonia and length of intensive care unit (ICU) stay., Methods: Patients were eligible if they were older than 15 years and either a Glasgow Coma Score (GCS) >4 with a negative brain computed tomography (CT) (no anatomic head injury), or a GCS >9 with a positive head CT (known anatomic head injury). Patients who required tracheostomy for facial/neck injuries were excluded. Patients were randomized to an intention to treat strategy of tracheostomy placement before day 8 or after day 28., Results: The study was halted after the first interim analysis. There were 60 enrolled patients, who had comparable demographics between groups. There was no significant difference between groups in any outcome variable including length of ventilator support, pneumonia rate, or death., Conclusion: A strategy of tracheostomy before day 8 postinjury in this group of trauma patients did not reduce the number of days of mechanical ventilation, frequency of pneumonia or ICU length of stay as compared with the group with a tracheostomy strategy involving the procedure at 28 days postinjury or more.

Background: Despite the large body of evidence suggesting a beneficial role of fever in the host response, antipyretic therapy is commonly employed for febrile critically ill patients. Our objective was to evaluate the impact of antipyretic therapy strategies on the outcomes of critically ill patients., Methods: Patients admitted to the Trauma Intensive Care Unit over a nine-month period were eligible for inclusion, except those with traumatic brain injury. Patients were randomized on day three of the ICU stay into aggressive or permissive groups. The aggressive group received acetaminophen 650 mg every 6 h for temperature of >38.5 degrees C and a cooling blanket was added for temperature of >39.5 degrees C. The permissive group received no treatment for temperature of >38.5 degrees C, but instead had treatment initiated at temperature of >40 degrees C, at which time acetaminophen and cooling blankets were used until temperature was <40 degrees C. Patient demographics, daily temperatures, systemic inflammatory response syndrome (SIRS) scores, multiple organ dysfunction syndrome (MODS) scores, and infections and complications were recorded., Results: Between December, 2002 and September, 2003, 572 patients were screened, of whom 82 met criteria for enrollment. Forty-four patients were randomized to the aggressive group and 38 patients were randomized to the permissive group for a total of 961 and 751 ICU days, respectively. There were 131 infections in the aggressive group and 85 infections in the permissive group (4 +/- 6 vs. 3 +/- 2 infections per patient, p = 0.26). There were seven deaths in the aggressive group and only one death in the permissive group (p = 0.06, Fisher Exact Test). The study was stopped after the first interim analysis due to the mortality difference, related to the issues of waiver of consent and the mandate for minimal risk., Conclusions: Aggressively treating fever in critically ill patients may lead to a higher mortality rate.

Background: Our recent experimental study showed that peripheral muscle tissue oxygen saturation (StO2), determined noninvasively by near-infrared spectroscopy (NIRS), was more reliable than systemic hemodynamics or invasive oxygenation variables as an index of traumatic shock. The purpose of this study was to establish the normal range of thenar muscle StO2 in humans and the relationship between shock state and StO2 in trauma patients., Methods: This was a prospective, nonrandomized, observational, descriptive study in normal human volunteers (n = 707) and patients admitted to the resuscitation area of our Level I trauma center (n = 150). To establish a normal StO2 range, an NIRS probe was applied to the thenar eminence of volunteers (normals). Subsequently, in a group of trauma patients, an NIRS probe was applied to the thenar eminence and data were collected and stored for offline analysis. StO2 monitoring was performed continuously and noninvasively, and values were recorded at 2-minute intervals. Five moribund trauma patients were excluded. Members of our trauma faculty, blinded to StO2 values, classified each patient into one of four groups (no shock, mild shock, moderate shock, and severe shock) using conventional physiologic parameters., Results: Mean +/- SD thenar StO2 values for each group were as follows: normals, 87 +/- 6% (n = 707); no shock, 83 +/- 10% (n = 85); mild shock, 83 +/- 10% (n = 19); moderate shock, 80 +/- 12% (n = 14); and severe shock, 45 +/- 26% (n = 14). The thenar StO2 values clearly discriminated the normals or no shock patients and the patients with severe shock (p < 0.05)., Conclusion: Decreased thenar muscle tissue oxygen saturation reflects the presence of severe hypoperfusion and near-infrared spectroscopy may be a novel method for rapidly and noninvasively assessing changes in tissue dysoxia.

Introduction: Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound--SUS) will reveal additional intra-abdominal injuries and hemoperitoneum., Methods: We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings., Results: Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum., Conclusion: A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.

Background: Few comparative studies have evaluated conventional and laparoscopic knots. The objective of this study was to evaluate laparoscopic knot reliability and identify which type of knot is most secure., Methods: Seven types of knots were compared; each one was conventionally tied with four and six throws and similarly by laparoscopy. Dinsmore nomenclature for knots was used. A tension meter was used to evaluate knot reliability, using the loop method, and percentage of failure by slipping and tensile strength was calculated for each group., Results: When S=S=S=S and S=S=S=S=S=S geometry are excluded, there was no difference between laparoscopic and conventional knot. A significant difference between four- and six-throw knots was shown. Excluding S=S=S=S=S=S geometry, all knots in the conventional six-throw group were secure. Intracorporeal 2X1X1X1X1 and 1X1X1X1X1X1 and extracorporeal SXS#SXS#SXS six-throw laparoscopic group knots were secure., Conclusions: Laparoscopic knots are as secure as conventional knots. All knots must be made with six throws because security is maximized.