Acinetobacter baumannii review project
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- 1. Acinetobacter baumannii review project Dr. Joseph Timpone Dr. Sonia Qasba Dr. Matthew Sincock
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. A. baumannii A. baumannii can be similar to pseudomonas in the sense that typically healthy people dont 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. A. Baumannii Resistance to multiple drugs can be through both overexpression of efflux pumps or expression of -lactamases (including ESBLs and metallo-- lactamases which can cause carbapenem resistance) This can necessitate use of drugs with greater toxicity (such as polymyxins) 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. 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. 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. 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. 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. 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. 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. Data collection Basic demographic data was collected including: Age Race Gender 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. 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. 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. 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. 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. 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. 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. 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. 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. Results Wellhow about you ask me about those in a few months? Questions? 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.