1083. Extreme- and Pan-drug Resistant Acinetobacter baumannii (XDR/PDR-Ab) and Carbapenemase-Producing Klebsiella pneumonia (KPC) Infections Following Solid Organ Transplant (SOT) Present Differently but Respond Best to Colistin + a Carbapenem (COL+CBM)
Session: Poster Abstract Session: Infections After Solid Organ Transplants
Saturday, October 22, 2011
Room: Poster Hall B1
Background: XDR (R to all agents except colistin) and PDR (resistant to all agents)-Ab and KPC infections among SOT pts are poorly described.

Methods: Retrospective review of SOT pts at UPMC.

Results: 58 and 80 pts developed XDR/PDR-Ab and KPC infections after SOT, respectively.  XDR/PDR-Ab and KPC infections were most common following cardiothoracic (CT) (47%, 27) and liver (45%, 36) or intestine Tx (20%, 16), respectively. 69% (40) and 61% (49) of XDR/PDR-Ab and KPC infections caused disease (dz), and the remainder colonization.  Median times to dz were 90 and 197 days.  28% and 57% of pts with dz were previously colonized by Ab and Klebsiella, respectively.  92% (37/40) of XDR/PDR-Ab dz involved lungs (VAP, 30; tracheobronchitis, 4; HAP, 3), whereas KPC dz included bacteremia (47%), VAP/HAP (24%), UTI (20%) and abdominal (8%).  For both XDR/PDR-Ab and KPC, lung Tx pts were more likely to have pneumonia, liver/intestine Tx pts to have bacteremia or abdominal, and kidney Tx pts to have UTI (p=0.04).  Median APACHE scores were similar for pts with dz due to XDR/PDR-Ab (19) and KPC (17), as were 28-day clinical success (45% and 47%) and in-house mortality rates (50% and 41%).  For dz by both pathogens, 28-day success rates were significantly higher for pts treated with regimens that included COL+CBM than other combinations (73% vs. 20%, p=0.0008; and 53% vs 25%, p=0.04, respectively).  Pts with KPC UTI had lower median APACHE (11, p=0.05) and higher success rates (70%, p=0.07) than other diseases. 

Conclusion: XDR/PDR-Ab most commonly caused pneumonia in CT Tx pts within the first 100 days, whereas KPC most commonly caused bacteremia or abdominal infections in liver or intestine Tx pts at later time points.  Successful treatment of pts infected with either XDR/PDR-Ab or KPC was more common with combination regimens that included COL+CBM, which was consistent with our prior reports of in vitro synergy.  Overall outcomes for XDR/PDR-Ab or KPC dz other than UTI were poor. 

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Cornelius Clancy, MD1, Ryan K. Shields, PharmD2, Eun J. Kwak, MD2, Fernanda Silveira, MD, MS2, Brian Potoski, PharmD2 and M. Hong Nguyen, MD2, (1)University of Pittsburgh and VA Pittsburgh, Pittsburgh, PA, (2)University of Pittsburgh, Pittsburgh, PA


C. Clancy, Pfizer: Grant Investigator, Research grant
Merck: Grant Investigator, Research support

R. K. Shields, Pfizer, Merck, Astellas: , Research grant and Research support

E. J. Kwak, None

F. Silveira, None

B. Potoski, None

M. H. Nguyen, Pfizer: Grant Investigator, Research support
Merck: Grant Investigator, Research grant

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