Molecular epidemiology of Acinetobacter baumannii spread in an adult intensive care unit under an endemic setting.
BACKGROUND
Acinetobacter baumannii (Ab) clones I, III, and IV were recovered in several Buenos Aires City hospitals. We investigated the prevalence of these clones with epidemic behavior (EB) in our intensive care unit (ICU) under an endemic setting and its spread.


METHODS
A 10-week prospective cohort study including surveillance cultures of newly admitted patients was conducted. Air, environment, and staff hands were weekly screened. In the seventh week, a new environmental cleaning protocol and a staff hand hygiene reeducation program were implemented.


RESULTS
Almost 15% of all screening samples (159/1042) were Ab positive. Up to the seventh week, carbapenem-resistant clone If was the main one recovered from patients, environmental frequently touched surfaces (EFTS), and staff hands screening samples. Few air samples were Ab positive. Clone I was also isolated from patients at admission. After the seventh week, a significant reduction of EFTS contamination and of clone If isolation was observed. During the last 3 weeks, clone I was no longer isolated from patients. Instead, the newly identified clone IVb was mainly cross transmitted. It was also recovered from staff hands and from EFTS. In the last week, clone If was again isolated from 1 bed rail.


CONCLUSIONS
Patients with EB clones-positive culture at admission provide verification that interhospital patient transfers play a role in these clones spread. However, subtypes such as clone If seem to be endemic in our ICU. EFTS showed to have potential for EB clones transmission via transient staff hand carriage. Transmission did not involve airborne route.
Barbolla
Raquel Eve
RE
Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Centrón
Daniela
D
Maimone
Stella
S
Rospide
Fernanda
F
Salgueira
Claudia
C
Altclas
Javier
J
Catalano
Mariana
M
D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification* / Q000302:isolation & purification; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001118:Argentina / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019353:Endemic Diseases; D004783:Environmental Microbiology; D006225:Hand / Q000382:microbiology; D006801:Humans; D007362:Intensive Care Units; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal