4. General Information
Catalase = positive
The purpose is to see if the
microbe has catalase or can
destroy chemical hydrogen
peroxide.
Oxidase = negative
Identifies organisms that
produce the enzyme
cytochrome oxidase.
5. General Information
Habitat
•soil, water, food,
sewage, & the
hospital
environment
•resistant to
desiccation and
disinfection
•Survive on moist
& dry surfaces
•forms bio-film on
catheters,
ventilators, and
other medical
devices
•Iraq/Afghanistan
8. General Information
Nutrition
•grows on various media
•can live in hospital settings 9 days after
patient leaves
•Acinetobacter calcoaceticus-baumanii
complex: glucose-oxidising nonhemolytic,
•Acinetobacter lwoffii: glucose-negative
nonhemolytic
•Acinetobacter haemolyticus: haemolytic on
blood agar.
9. Pathogenesis
Diseases
•Bloodstream infections: pneumonia, urinary tract
infections, and septicemia
•mostly respiratory >> can lead to death
•32 species: cause of 80% of infections
•nosocomial
Examples of Major Infections
•Ventilator-associated pneumonia
•Urinary tract
•Bloodstream infection
•Secondary meningitis
•Skin/wound infections
•Endocarditis
•CAPD-associated peritonitis
•Ventriculitis
17. Pathogenesis
Symptoms
•standard infection
symptoms i.e.
fever
•death within 14
days of surgery
Predisposed factors
•Malignancy
•Trauma
•Burns
•Surgical wound infections
•Neonates
•Low birth weight
•Need for mechanical ventilation
Diagnosis
•clinical culture of
blood, sputum, urine,
wound, sterile body
fluid, etc.
19. Pathogenesis
Treatment
• Will collect: age, sex, occupation, hospital location at the time of positive culture
(ER, medical ward, ICU etc), date of positive culture, prior hospitalization, receipt of
outpatient dialysis, home care or other regular medical care (eg, outpatient
chemotherapy), presence of invasive devices, receipt of antibiotics, etc.
•Carbapenems (Imipenem and Meropenem) - growing resistance
•Others: Polymyxin, Tigecycline and Aminoglycosides
22. Methods for control and prevention of multidrug-resistant Acinetobacter infection.
Pathogenesis
Prevention:
•Wash hands
•contact precautions
•environmental decontamination
23. Antibiotic Resistance
•naturally transformable
•AcomFECB and
comQLONM allow uptake
of DNA from the
environment
•administration of
subtheraputic doses of
antimicrobial agents, drug
overuse, interrupted
courses of treatment, and
poor tissue penetration by
antimicrobial agent
•Medical interventions
increasing the
Acinetobacter Infections
24. Antibiotic Resistance
• Most A. baumannii resistant: tampicillin,
Carbenicillin, Cefotaxime and
Chloramphenicol.
• Increasing resistance:Gentamycin,
tobramycin and amikacin is increasing.
• May retain: Fluoroquinolones,
ceftazidime,TrimethoprimSulphmethoxazole, Doxycycline, Polymyxin
B, colistin, imipenem and meropenem
25. Antibiotic Resistance
"Acinetobacter baumannii
membrane transporter PilQ
allows initial entry of foreign DNA
into the cell. Foreign DNA is then
bound by protein ComE and is
directed to cytoplasmic
membrane transporter ComA."
28. Works Cited
•Federico Perez, Andrea M. Hujer, Kristine M. Hujer, BrookeK. Decker, Philip N. Rather and
Robert A. Bonomo Antimicrob. Agents Chemother. 2007, 51(10):3471.
DOI:10.1128/AAC.01464-06. Published Ahead of Print 23 July 2007.
•George M. Eliopoulos, Lisa L. Maragakis, and Trish M. Perl Acinetobacter baumannii:
Epidemiology, Antimicrobial Resistance, and Treatment Options Clin Infect Dis. (2008) 46 (8):
1254-1263 doi:10.1086/529198
•Hujer, K. Hujer, A. Hulten, E. Bajaksouzian, S. Adams, J. Donskey, C. Ecker, D. Massire, C.
Eshoo, M., Sampath, R., Thomson, J. Rather, P., Craft, D., Fishbain, J., Ewell, A., Jacobs, M.
Paterson, D., Bonomo, R. “Analysis of Antibiotic Resistance Genes in Multidrug-Resistant
Acinetobacter sp. Isolates from Military and Civilian Patients treated at the Walter Reed Army
Medical Center.” Antimicrboia Agents and Chemotherapy. Dec. 2006. Volume. 50, No. 12.
4114-4123.
•José M. Cisneros, Maria J. Reyes, Jerónimo Pachón, Berta Becerril, Francisco J. Caballero,
José L. García Garmendia, Carlos Ortiz, and Adelaido R. Cobacho Bacteremia Due to
Acinetobacter baumannii: Epidemiology, Clinical Findings, and Prognostic Features Clin Infect
Dis. (1996) 22 (6): 1026-1032 doi:10.1093/clinids/22.6.1026
•Lenie Dijkshoorn, Alexandr Nemec & Harald Seifert An increasing threat in hospitals:
multidrug-resistant Acinetobacter baumannii Nature Reviews Microbiology 5, 939-951
(December 2007) doi:10.1038/nrmicro1789
•Mortensen, B. L. and Skaar, E. P. (2012), Host–microbe interactions that shape the
pathogenesis of Acinetobacter baumannii infection. Cellular Microbiology, 14: 1336–1344. doi:
10.1111/j.1462-5822.2012.01817.x
