Hostname: page-component-8448b6f56d-42gr6 Total loading time: 0 Render date: 2024-04-17T20:05:30.228Z Has data issue: false hasContentIssue false

Prevalence of and Risk Factors for Multidrug-Resistant Acinetobacter baumannii Colonization Among High-Risk Nursing Home Residents

Published online by Cambridge University Press:  15 June 2015

Lona Mody*
Division of Geriatric and Palliative Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan Geriatrics Research Education and Clinical Center, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
Kristen E. Gibson
Division of Geriatric and Palliative Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan
Amanda Horcher
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
Katherine Prenovost
Veterans Affairs Center for Clinical Management Research, Ann Arbor, Michigan
Sara E. McNamara
Division of Geriatric and Palliative Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan
Betsy Foxman
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
Keith S. Kaye
Division of Infectious Diseases, Detroit Medical Center and Wayne State University, Detroit, Michigan
Suzanne Bradley
Infectious Diseases Section, Veterans Affairs Ann Arbor Healthcare System and the University of Michigan Medical School, Ann Arbor, Michigan
Address correspondence to Lona Mody, MD, MSc, Division of Geriatric and Palliative Care Medicine, University of Michigan Medical School, 300 N. Ingalls Rd, Rm 905, Ann Arbor, MI 48109 (



To characterize the epidemiology of multidrug-resistant (MDR) Acinetobacter baumannii colonization in high-risk nursing home (NH) residents.


Nested case-control study within a multicenter prospective intervention trial.


Four NHs in Southeast Michigan.


Case patients and control subjects were NH residents with an indwelling device (urinary catheter and/or feeding tube) selected from the control arm of the Targeted Infection Prevention study. Cases were residents colonized with MDR (resistant to ≥3 classes of antibiotics) A. baumannii; controls were never colonized with MDR A. baumannii.


For active surveillance cultures, specimens from the nares, oropharynx, groin, perianal area, wounds, and device insertion site(s) were collected upon study enrollment, day 14, and monthly thereafter. A. baumannii strains and their susceptibilities were identified using standard microbiologic methods.


Of 168 NH residents, 25 (15%) were colonized with MDR A. baumannii. Compared with the 143 controls, cases were more functionally disabled (Physical Self-Maintenance Score >24; odds ratio, 5.1 [95% CI, 1.8–14.9]; P<.004), colonized with Proteus mirabilis (5.8 [1.9–17.9]; P<.003), and diabetic (3.4 [1.2–9.9]; P<.03). Most cases (22 [88%]) were colonized with multiple antibiotic-resistant organisms and 16 (64%) exhibited co-colonization with at least one other resistant gram-negative bacteria.


Functional disability, P. mirabilis colonization, and diabetes mellitus are important risk factors for colonization with MDR A. baumannii in high-risk NH residents. A. baumannii exhibits widespread antibiotic resistance and a preference to colonize with other antibiotic-resistant organisms, meriting enhanced attention and improved infection control practices in these residents.

Infect Control Hosp Epidemiol 2015;36(10):1155–1162

Original Articles
© 2015 by The Society for Healthcare Epidemiology of America. All rights reserved 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


1. Dijkshoorn, L, Nemec, A, Seifert, H. An increasing threat in hospitals: multidrug-resistant Acinetobacter baumannii . Nat Rev Microbiol 2007;5:939951.Google Scholar
2. Albrecht, MC, Griffith, ME, Murray, CK, et al. Impact of Acinetobacter infection on the mortality of burn patients. J Am Coll Surg 2006;203:546550.CrossRefGoogle ScholarPubMed
3. Dallo, SF, Weitao, T. Insights into Acinetobacter war-wound infections, biofilms, and control. Adv Skin Wound Care 2010;23:169174.Google Scholar
4. Charnot-Katsikas, A, Dorafshar, AH, Aycock, JK, David, MZ, Weber, SG, Frank, KM. Two cases of necrotizing fasciitis due to Acinetobacter baumannii . J Clin Microbiol 2009;47:258263.Google Scholar
5. Wisplinghoff, H, Bischoff, T, Tallent, SM, Seifert, H, Wenzel, RP, Edmond, MB. Nosocomial bloodstream infections in US hospitals: analysis of 24,179 cases from a prospective nationwide surveillance study. Clin Infect Dis 2004;39:309317.CrossRefGoogle Scholar
6. Giamarellou, H, Antoniadou, A, Kanellakopoulou, K. Acinetobacter baumannii: a universal threat to public health? Int J Antimicrob Agents 2008;32:106119.Google Scholar
7. Strausbaugh, LJ, Crossley, KB, Nurse, BA, Thrupp, LD. Antimicrobial resistance in long-term-care facilities. Infect Control Hosp Epidemiol 1996;17:129140.Google Scholar
8. Poirel, L, Nordmann, P. Carbapenem resistance in Acinetobacter baumannii: mechanisms and epidemiology. Clin Microbiol Infect 2006;12:826836.Google Scholar
9. Urban, C, Segal-Maurer, S, Rahal, JJ. Considerations in control and treatment of nosocomial infections due to multidrug-resistant Acinetobacter baumannii . Clin Infect Dis 2003;36:12681274.CrossRefGoogle ScholarPubMed
10. Neely, AN, Maley, MP, Warden, GD. Computer keyboards as reservoirs for Acinetobacter baumannii in a burn hospital. Clin Infect Dis 1999;29:13581360.Google Scholar
11. Peleg, AY, Potoski, BA, Rea, R, et al. Acinetobacter baumannii bloodstream infection while receiving tigecycline: a cautionary report. J Antimicrob Chemother 2007;59:128131.Google Scholar
12. Montefour, K, Frieden, J, Hurst, S, et al. Acinetobacter baumannii: an emerging multidrug-resistant pathogen in critical care. Crit Care Nurse 2008;28:1525.CrossRefGoogle ScholarPubMed
13. Maragakis, LL, Perl, TM. Acinetobacter baumannii: epidemiology, antimicrobial resistance, and treatment options. Clin Infect Dis 2008;46:12541263.Google Scholar
14. Furuno, JP, Hebden, JN, Standiford, HC, et al. Prevalence of methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii in a long-term acute care facility. Am J Infect Control 2008;36:468471.Google Scholar
15. Karageorgopoulos, DE, Falagas, ME. Current control and treatment of multidrug-resistant Acinetobacter baumannii infections. Lancet Infect Dis 2008;8:751762.Google Scholar
16. Wong, TH, Tan, BH, Ling, ML, Song, C. Multi-resistant Acinetobacter baumannii on a burns unit—clinical risk factors and prognosis. Burns 2002;28:349357.Google Scholar
17. Arias, CA, Murray, BE. Antibiotic-resistant bugs in the 21st century—a clinical super-challenge. N Engl J Med 2009;360:439443.CrossRefGoogle ScholarPubMed
18. Longo, F, Vuotto, C, Donelli, G. Biofilm formation in Acinetobacter baumannii . New Microbiol 2014;37:119127.Google Scholar
19. Zhang, D, Xia, J, Xu, Y, et al. Biological features of biofilm-forming ability of Acinetobacter baumannii strains derived from 121 elderly patients with hospital-acquired pneumonia. [published online December 28, 2014] Clin Exp Med. doi:10.1007/s10238-014-0333-2.Google Scholar
20. Luo, TL, Rickard, AH, Srinivasan, U, Kaye, KS, Foxman, B. Association of blaOXA-23 and bap with the persistence of Acinetobacter baumannii within a major healthcare system [published online March 12, 2015] Front Microbiol. doi:10.3389/fmicb.2015.00182.Google Scholar
21. Gao, J, Zhao, X, Bao, Y, et al. Antibiotic resistance and OXA-type carbapenemases-encoding genes in airborne Acinetobacter baumannii isolated from burn wards. Burns 2014;40:295299.Google Scholar
22. Gootz, TD, Marra, A. Acinetobacter baumannii: an emerging multidrug-resistant threat. Expert Rev Anti Infect Ther 2008;6:309325.CrossRefGoogle ScholarPubMed
23. Richet, H, Fournier, PE. Nosocomial infections caused by Acinetobacter baumannii: a major threat worldwide. Infect Control Hosp Epidemiol 2006;27:645646.CrossRefGoogle Scholar
24. Sengstock, DM, Thyagarajan, R, Apalara, J, Mira, A, Chopra, T, Kaye, KS. Multidrug-resistant Acinetobacter baumannii: an emerging pathogen among older adults in community hospitals and nursing homes. Clin Infect Dis 2010;50:16111616.CrossRefGoogle ScholarPubMed
25. de Medina, T, Carmeli, Y. The pivotal role of long-term care facilities in the epidemiology of Acinetobacter baumannii: another brick in the wall. Clin Infect Dis 2010;50:16171618.Google Scholar
26. Mortensen, E, Trivedi, KK, Rosenberg, J, et al. Multidrug-resistant Acinetobacter baumannii infection, colonization, and transmission related to a long-term care facility providing subacute care. Infect Control Hosp Epidemiol 2014;35:406411.Google Scholar
27. Bradley, SF. Issues in the management of resistant bacteria in long-term-care facilities. Infect Control Hosp Epidemiol 1999;20:362366.Google Scholar
28. Peleg, AY, Seifert, H, Paterson, DL. Acinetobacter baumannii: emergence of a successful pathogen. Clin Microbiol Rev 2008;21:538582.CrossRefGoogle ScholarPubMed
29. Pop-Vicas, A, Mitchell, SL, Kandel, R, Schreiber, R, D’Agata, EM. Multidrug-resistant gram-negative bacteria in a long-term care facility: prevalence and risk factors. J Am Geriatr Soc 2008;56:12761280.CrossRefGoogle Scholar
30. Muder, RR, Brennen, C, Goetz, AM, Wagener, MM, Rihs, JD. Association with prior fluoroquinolone therapy of widespread ciprofloxacin resistance among gram-negative isolates in a Veterans Affairs medical center. Antimicrob Agents Chemother 1991;35:256258.Google Scholar
31. Muder, RR, Brennen, C, Drenning, SD, Stout, JE, Wagener, MM. Multiple antibiotic-resistant gram-negative bacilli in a long-term-care facility: a case-control study of patient risk factors and prior antibiotic use. Infect Control Hosp Epidemiol 1997;18:809813.Google Scholar
32. Mody, L, Bradley, SF, Galecki, A, et al. Conceptual model for reducing infections and antimicrobial resistance in skilled nursing facilities: focusing on residents with indwelling devices. Clin Infect Dis 2011;52:654661.CrossRefGoogle ScholarPubMed
33. Mody, L, Krein, SL, Saint, S, et al. A targeted infection prevention intervention in nursing home residents with indwelling devices: a cluster randomized trial. [published online March 16, 2015] JAMA Intern Med. doi:10.1001/jamainternmed.2015.132.Google Scholar
34. Charlson, ME, Pompei, P, Ales, KL, MacKenzie, CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987;40:373383.Google Scholar
35. Lawton, MP, Brody, EM. Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist 1969;9:179186.CrossRefGoogle ScholarPubMed
36. Wang, L, Lansing, B, Symons, K, et al. Infection rate and colonization with antibiotic-resistant organisms in skilled nursing facility residents with indwelling devices. Eur J Microbiol Infect Dis 2012;31:17971804.Google Scholar
37. Dubois, D, Grare, M, Prere, M, Segonds, C, Marty, N, Oswald, E. Performances of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for rapid identification of bacteria in routine clinical microbiology. J Clin Microbiol 2012;50:25682576.Google Scholar
38. Clinical and Laboratory Standards Institute (CLSI). Performance standards for antimicrobial disk susceptibility tests; approved standard, 11th edition. CLSI document Wayne, PA: CLSI, 2012:M02A11.Google Scholar
39. Marchaim, D, Chopra, T, Perez, F, et al. Outcomes and genetic relatedness of carbapenem-resistant Enterobacteriaceae at Detroit medical center. Infect Control Hosp Epidemiol 2011;32:861871.Google Scholar
40. Marchaim, D, Perez, F, Lee, J, et al. “Swimming in resistance”: co-colonization with carbapenem-resistant Enterobacteriaceae and Acinetobacter baumannii or Pseudomonas aeruginosa . Am J Infect Control 2012;40:830835.CrossRefGoogle ScholarPubMed
41. Mammina, C, Bonura, C, Vivoli, AR, et al. Co-colonization with carbapenem-resistant Klebsiella pneumonia and Acinetobacter baumannii in intensive care unit patients. Scand J Infect Dis 2013;45:629634.Google Scholar
42. Dommeti, P, Wang, L, Flannery, EL, Symons, K, Mody, L. Patterns of ciprofloxacin-resistant gram-negative bacteria colonization in nursing home residents. Infect Control Hosp Epidemiol 2011;32:177180.Google Scholar
43. Fisch, J, Lansing, B, Wang, L, et al. New acquisition of antibiotic-resistant organisms in skilled nursing facilities. J Clin Microbiol 2012;50:16981703.CrossRefGoogle ScholarPubMed
44. Min, L, Galecki, A, Mody, L. Functional disability and nursing resource utilization are predictive of antimicrobial resistance in nursing homes. J Am Geriatr Soc 2015;63:659666.CrossRefGoogle Scholar
45. Metan, G, Sariquzel, F, Sumerkan, B. Factors influencing survival in patients with multi-drug-resistant Acinetobacter bacteraemia. Eur J Intern Med 2009;20:540544.Google Scholar
46. Alsultan, AA, Hamouda, A, Evans, BA, Amyes, SG. Acinetobacter baumannii: emergence of four strains with novel bla (OXA-51-like) genes in patients with diabetes mellitus. J Chemother 2009;21:290295.Google Scholar