Acinetobacter baumannii review project


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Acinetobacter baumannii review project

  1. 1. Acinetobacter baumannii review project Dr. Joseph Timpone Dr. Sonia Qasba Dr. Matthew Sincock
  2. 2. Acinetobacer baumannii A. baumannii is a gram negative bacteria that is often a source of nosocomial infections Unfortunately it has the potential to often be multi-drug resistant Recently it has gotten more attention because of numerous cases being reported in soldiers from Iraq and Afghanistan Interestingly, during the Vietnam war this was the most common gram negative bacillus to contaminate wounds
  3. 3. A. baumannii A. baumannii can be similar to pseudomonas in the sense that typically “healthy people don’t get it” It is uncommon across the U.S. in general medical floors, but can reach a very high percentage of infections in ICU settings (and may be on the rise)
  4. 4. A. Baumannii Resistance to multiple drugs can be through both overexpression of efflux pumps or expression of ß-lactamases (including ESBLs and metallo-ß- lactamases which can cause carbapenem resistance) This can necessitate use of drugs with greater toxicity (such as polymyxins)
  5. 5. A. baumanni Resistance genes can often be found on the same portion of the bacterial genome and therefore co-expression can be problematic This means that it is possible that use of “just a touch of cipro” can place a patient at increased risk for MRSA and/or MDR organisms (like a. baumannii) A. baumannii has been placed on the IDSA “hit list” as a dangerous microbe
  6. 6. A. baumannii Unfortunately, even cases of colistin resistance appear in the literature, and a. baumannii was singled out as more problematic than pseudomonas Tigecyline has been shown to have activity against a. baumannii (but not pseudomonas) but not many other options
  7. 7. Background This project is focused on looking at infections with a. baumannii that occurred at GUH It was noted by the ID staff that there were numerous patients infected with a. baumannii and it was thought that this deserved a closer look
  8. 8. Background What made these infections stand out was that: They were often multi-drug resistant They were occurring frequently in the ICU setting They were often very difficult to treat The study is similar to a study involving multi-drug resistant pseudomonas infections
  9. 9. Background Currently this project is in the final portion of the data collection phase Statistical analysis will begin once the collection phase is complete As results are not available, this talk will focus more on study design/questions that we are hoping to answer
  10. 10. Data collection First the patient population had to be identified Using Azzyxi and the micro lab records we were able to identify all patients who had cultures positive for a. baumannii over a period of three years (2004-2006)
  11. 11. Data collection From this group of patients those appropriate to the study were defined as: Age 18 or older They must have been admitted to the hospital The culture must represent an infection and not only colonization
  12. 12. Data collection Basic demographic data was collected including: Age Race Gender
  13. 13. Questions… The next portion will focus more on which questions were asked and how that affected the focus of our data collection Each question that is trying to be answered by the review has pertinent questions in our data abstraction form
  14. 14. Goals Are there common threads in terms of the reason for admission or the past medical history Reason for admission Duration of admission Past medical history Initial hospital unit on admission Was the patient ever in an intensive care unit setting
  15. 15. Goals Are the patients in question acquiring the infection at GUH or at an outside facility? Was the patient recently hospitalized Was the patient transferred from another hospital Was the patient coming from a nursing home
  16. 16. Goals What are the risk factors these patients share for this particular infection Presence of central line, foley, a-line, nasogastric tube, or any other foreign lines History of chronic medical conditions such as DM, CHF, ESRD, ESLD, alcohol abuse, etc. Recent immunosuppresive therapy with either steroids, chemotherapy, or other cytotoxic/immunomodulator agents
  17. 17. Goals Risk factors continued Conditions such as HIV or hematologic malignancy that can affect immune function Recent surgery/trauma Recent episode of SIRS/shock that could have stressed the immune system
  18. 18. Goals Did the antibiotic resistance profile of the a. baumannii remain the same over time or change This is an important question because it speaks to the effect of antibiotics and how they can inadvertently cause more serious infections further into the hospitalization
  19. 19. Goals Resistance profile Did the profile change over time Does a relation exist between prior exposure to antibiotics and development of resistance Does a relation exist between development of resistance and attempts at treating the infection
  20. 20. Goals Data was collected on all antibiotic exposure both prior to the first culture positive for a. baumanni and after that culture Changes in resistance patterns over time were also recorded
  21. 21. Goals Outcomes Was the infection from a. baumannii successfully treated clinically Was there documented clearance of the infection by repeat culture Did the patient survive to discharge Did the patient discharge to home or to another facility
  22. 22. Results Well…how about you ask me about those in a few months? Questions?
  23. 23. References  Mandell, Bennett & Dolin: Principles and Practices of Infectious Diseases, 6th edition. Churchhill/Livingston. Chapter 219.  Importation of multidrug-resistant Acinetobacter spp infections with casulaties from Iraq. Jones A. et. al. The Lancet Infectious Diseases 01-Jun-2006; 6 (6): 317-8  Resistance in nonfermenting gram-negative bacteria: multidrug resistance to the maximum. McGowan JE et. al. American Journal of Medicine. 01-Jun-2006; 119 (6 Suppl 1): S29-36  First-generation fluoroquinolone use and subsequent emergence of multiple drug-resistant bacteria in the intensive care unit. Nseir S. et. al. Critical Care Medicine. 01-Feb-2005; 33(2): 283-9.  ISDA releases “hit list”. Nelson R. Lancet Infectious Diseases. May 2006; 6(5): 265  Colistin: the re-emerging antibiotic for multidrug-resistant Gram- negative bacterial infections. Li J. et. Al. Lancet Infectious Diseases. 01-Sept-2006; 6(9): 589-601.  Mechanisms of resistance of bacteria causing ventilator associated pneumonia. Szabo D. et al. Clinical Chest Medicine. 01-Mar-2005; 26(1): 75-9.