Complete genome sequence of hypervirulent and outbreak-associated Acinetobacter baumannii strain LAC-4: epidemiology, resistance genetic determinants and potential virulence factors.

Acinetobacter baumannii is an important human pathogen due to its multi-drug resistance. In this study, the genome of an ST10 outbreak A. baumannii isolate LAC-4 was completely sequenced to better understand its epidemiology, antibiotic resistance genetic determinants and potential virulence factors. Compared with 20 other complete genomes of A. baumannii, LAC-4 genome harbors at least 12 copies of five distinct insertion sequences. It contains 12 and 14 copies of two novel IS elements, ISAba25 and ISAba26, respectively. Additionally, three novel composite transposons were identified: Tn6250, Tn6251 and Tn6252, two of which contain resistance genes. The antibiotic resistance genetic determinants on the LAC-4 genome correlate well with observed antimicrobial susceptibility patterns. Moreover, twelve genomic islands (GI) were identified in LAC-4 genome. Among them, the 33.4-kb GI12 contains a large number of genes which constitute the K (capsule) locus. LAC-4 harbors several unique putative virulence factor loci. Furthermore, LAC-4 and all 19 other outbreak isolates were found to harbor a heme oxygenase gene (hemO)-containing gene cluster. The sequencing of the first complete genome of an ST10 A. baumannii clinical strain should accelerate our understanding of the epidemiology, mechanisms of resistance and virulence of A. baumannii.

Is prehospital endotracheal intubation associated with improved outcomes in isolated severe head injury? A matched cohort analysis.

INTRODUCTION: Prehospital endotracheal intubation (ETI) following traumatic brain injury in urban settings is controversial. Studies investigating admission arterial blood gas (ABG) patterns in these instances are scant. HYPOTHESIS: Outcomes in patients subjected to divergent prehospital airway management options following severe head injury were studied. METHODS: This was a retrospective propensity-matched study in patients with isolated TBI (head Abbreviated Injury Scale (AIS) ≥ 3) and Glasgow Coma Scale (GCS) score of ≤ 8 admitted to a Level 1 urban trauma center from January 1, 2003 through October 31, 2011. Cases that had prehospital ETI were compared to controls subjected to oxygen by mask in a one to three ratio for demographics, mechanism of injury, tachycardia/hypotension, Injury Severity Score, type of intracranial lesion, and all major surgical interventions. Primary outcome was mortality and secondary outcomes included admission gas profile, in-hospital morbidity, ICU length of stay (ICU LOS) and hospital length of stay (HLOS). RESULTS: Cases (n = 55) and controls (n = 165) had statistically similar prehospital and in-hospital variables after propensity matching. Mortality was significantly higher for the ETI group (69.1% vs 55.2% respectively, P = .011). There was no difference in pH, base deficit, and pCO2 on admission blood gases; however the ETI group had significantly lower pO2 (187 (SD = 14) vs 213 (SD = 13), P = .034). There was a significantly increased incidence of septic shock in the ETI group. Patients subjected to prehospital ETI had a longer HLOS and ICU LOS. CONCLUSION: In isolated severe traumatic brain injury, prehospital endotracheal intubation was associated with significantly higher adjusted mortality rate and worsened admission oxygenation. Further prospective validation of these findings is warranted.

Acid-citrate-dextrose Formula A versus heparin as primary catheter lock solutions for therapeutic apheresis.

BACKGROUND: Unfractionated heparin (UFH) is a commonly used catheter lock solution, but may lead to various complications. Acid-citrate-dextrose Formula A (ACD-A), the standard anticoagulant used in therapeutic apheresis (TA), is an alternative. We compared the efficacy of these two anticoagulants as primary catheter lock solutions. STUDY DESIGN AND METHODS: The following outcomes were analyzed retrospectively for all TA procedures performed between July 2009 and March 2012: patent, partial occlusion, total occlusion, catheter-related blood stream infection, tissue plasminogen activator use, and premature catheter removal. RESULTS: Our primary data set included 5964 total catheter days, 3020 procedures, and 427 TA courses. The UFH group comprised 3444 catheter days and 1880 procedures; the ACD-A group, 2520 catheter days and 1140 procedures. Overall catheter-related outcomes differed by not more than 5.3% for the primary analysis and when stratified by short-term (≤10 days) duration or short dwell times (<3 days). When stratified by long-term duration (>10 days) and long dwell times (>3 days), differences increased to not more than 10.4 and 22.4%, respectively. CONCLUSIONS: For short-term courses and short dwell times, UFH and ACD-A appear equally effective; UFH appears superior to ACD-A in the setting of long-term courses and long dwell times. Major catheter-related complications were rare and occurred with similar frequency in both groups. For most indications, ACD-A appears to be a reasonable alternative to heparin; however, an adequately powered, randomized trial would be required to definitively address this issue.

Rituximab as successful therapy in a patient with refractory paroxysmal cold hemoglobinuria.

BACKGROUND: Paroxysmal cold hemoglobinuria (PCH) is a rare autoimmune hemolytic anemia (AIHA) attributed to a biphasic hemolysin known as the Donath-Landsteiner (DL) antibody. It is most commonly encountered as an acute transient AIHA after a viral infection in children; the disease resolves after cessation of the infection. The rarest form of PCH is a chronic form in adults that is not (nowadays) associated with infection and is not responsive to conventional therapies. Rituximab has been found to be effective therapy in other forms of AIHA, such as cold agglutinin syndrome, that are refractory to conventional therapies. We describe a case of PCH refractory to steroids that responded to rituximab therapy on two separate occasions. CASE REPORT: A 64-year-old woman with fatigue was found to be profoundly anemic with laboratory findings consistent with AIHA. She was admitted for the workup and management of her disease after she failed to respond to a course of oral steroids. Laboratory evaluation demonstrated a positive DL test suggesting PCH. She was given a course of rituximab that resulted in normalization of her hemoglobin concentration. She presented 9 months later with recurrent hemolysis. She was given another course of rituximab that again resulted in termination of hemolysis. The patient remained in remission since her last dose of rituximab 19 months previously. CONCLUSION: To our knowledge, this is the first report of an adult case of refractory PCH successfully treated with rituximab.

Safe handling and administration of blood components: review of practical concepts.

CONTEXT: The more advanced we become, the more evident are the infectious and noninfectious risks of the blood supply. Infectious risks are somewhat straightforward and are addressed by implementing stricter donor criteria and testing. The noninfectious risks, however, are more complicated. Each step in the transfusion process, beginning with the physician who orders a transfusion to the actual transfusion of the component, is subject to adverse outcomes and increases the noninfectious risks of transfusion. The challenges to provide the safest blood possible with zero risk have resulted in the implementation of stringent standards from both the American Association of Blood Banks and the Joint Commission on Accreditation of Healthcare Organizations. OBJECTIVE: A series of case scenarios serve as the basis for discussion of the risks, which affect the safety and administration of blood components, inherent in the transfusion process. DATA SOURCES: Journals, textbooks, Internet. CONCLUSIONS: The transfusion process is a complex multistep process with inherent risks. Infectious risks of transfusion are being adequately addressed such that the noninfectious risks of transfusion are becoming much more evident. Patient safety can be compromised if each step of the transfusion process is not completed according to established policies and procedures at each individual institution.

Ensuring timely completion of type and screen testing and the verification of ABO/Rh status for elective surgical patients.

CONTEXT: A blood bank can provide compatible blood for an elective surgical procedure, provided a blood sample is received by the laboratory with sufficient time to allow pretransfusion testing and acquire enough compatible red blood cell units. With the push for same-day admission surgical procedures, a patient's pretransfusion blood sample is often collected the morning of surgery. However, if blood is needed, compatible units might not be immediately available. OBJECTIVE: To define and improve the process of completing presurgical/preadmission type and screen testing and verifying the ABO/Rh status of scheduled surgical patients before they receive a transfusion. STUDY DESIGN: A list of surgical procedures that might necessitate blood transfusion was created. A checklist was used to ensure that the preoperative clinic nurse collects a baseline pretransfusion blood sample for type and screen testing from patients scheduled for a listed procedure. A new pretransfusion specimen was received on the day of surgery, if needed, so that a current specimen would be available for compatibility testing and to verify the accuracy of the patient's ABO/Rh status in case blood was requested. RESULTS: During the 1-year study period, 666 patients qualified for baseline type and screen testing. Cholecystectomy was the most commonly scheduled surgery. In 99% of cases, a baseline type and screen specimen was received in the laboratory at least 1 day before surgery. The interval between the preoperative clinic visit and date of surgery varied from same day (6 patients) to 3 months. CONCLUSION: Timely receipt of a presurgical specimen for type and screen testing and verification of a patient's ABO/Rh status can be ensured when clinical services collaborate and when the hospital blood utilization committee provides oversight to improve compliance.

Storage and transfusion of infected autologous blood or components: a survey of North American laboratories.

CONTEXT: Many patients request that autologous blood or components be collected and available for use during scheduled surgical or invasive medical procedures to avoid exposure to human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) from allogeneic transfusions. Some patients from whom autologous blood is collected are themselves infected with HIV, HBV, or HCV. However, unlike HIV-, HBV-, or HCV-infected allogeneic blood and components, which must be excluded from the community blood supply, infected autologous blood and components are allowed to be stored in hospitals and transfused back to the patients (autologous donors) from whom the blood was collected. Although the transfusion of HIV-, HBV-, or HCV-infected autologous blood or components does not present a risk to the autologous donor, such a transfusion presents a risk to other patients, considering that at least 1 in every 25,000 transfusions are administered to the wrong individual. OBJECTIVE: To determine if hospital transfusion services store and/or transfuse autologous blood or components infected with HIV, HBV, and/or HCV. DESIGN: An educational enhancement subsection of a College of American Pathologists Proficiency Testing Survey (J-C 2003) assessed transfusion service practices for storing and/or transfusing HIV-, HBV-, and HCV-infected autologous blood and components. SETTING AND PARTICIPANTS: A total of 4251 participants were asked whether they stored and/or transfused autologous blood or components and whether these stored blood products included those that were infected with HIV, HBV, or HCV. RESULTS: Of the 4251 survey respondents, 3561 provided data regarding their autologous blood and component storage and/or transfusion practices. A total of 2988 participants reported that they store and/or transfuse autologous blood or components. A total of 2390 respondents reported that they do not test autologous donations collected in their own institution for evidence of infection with HIV, HBV, or HCV. Most survey participants reported that even if an autologous donation is tested and found to be infected they would still be willing to store and transfuse the blood component, according to which agent was causing the infection: HIV (n = 1867), HBV (n = 2158), or HCV (n = 2233). CONCLUSION: Most North American hospitals do not test autologous blood donations that they collect in their own institution for evidence of infection with HIV, HBV, or HCV, leading to the conclusion that infected autologous blood components are being stored and transfused. Even when autologous donations are tested and found to be infected with HIV, HBV, or HCV, most North American hospitals would be willing to store and/or transfuse the infected autologous blood components.

Phenotype matching of donor red blood cell units for nonalloimmunized sickle cell disease patients: a survey of 1182 North American laboratories.

CONTEXT: The transfusion of donor red blood cell units (RBCs) that lack certain red cell antigens (such as C, E, and K) when the corresponding antigens are absent from the recipient's red cells has been shown to reduce the risk of red cell alloimmunization in sickle cell disease patients. However, data are limited regarding the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. OBJECTIVE: To determine the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. DESIGN: An educational subsection of a College of American Pathologists Proficiency Testing Survey (J-C 2003) assessed transfusion service practices regarding performance of red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients and how transfusion services use this information for the selection of donor RBCs. The data analysis of the survey included 1182 North American laboratories. RESULTS: Data from 1182 laboratories were included in the survey analysis, of which the majority (n = 743) reported that they did not routinely perform phenotype testing of sickle cell disease patients for antigens other than ABO and D. The other 439 laboratories reported that they did routinely perform phenotype testing of sickle cell disease patients for antigens in addition to ABO and D. The majority of these 439 laboratories (three fourths; n = 330) reported that they used these patient data for prophylactic matching with donor RBCs when sickle cell disease patients required transfusion. When phenotype-matched donor RBCs were used, the antigens most commonly matched (85% of the time) were C, E, and K. CONCLUSIONS: The majority of North American hospital transfusion service laboratories do not determine the red cell antigen phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D. Those laboratories that do determine the red cell phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D most commonly match for C, E, and K antigens when phenotype-matched donor RBCs are used.