Screening cultures for multidrug-rresistant acinetobacter and MRSA in hospitalised patients

Abstract number: P1123

Garcia M., Nogués A., Aramburu J., Gassiot P., Barcenilla F., Manonelles A., Jover A.

Objectives: The aim of this study was to describe the microbiological performance of screening cultures (SC) for multiresistant Acinetobacter spp. (ACI) and meticillin resistant Staphylococcus aureus (MRSA) isolated from hospitalised patients.

Methods: Axillary (A), Faringeal (F), Nasal (N), and Rectal (R) swabs for carriers control of ACI and MRSA received from hospitalised adult patiens were studied during a year (October 2006 to September 2007). In the same period, prospective SC were performed in all Intensive Cure Unit (ICU) patients in the first 24 h of their admission.

Samples were processed by conventional methods, and also in an ACI selective medium (Leeds medium, Bio-Médics, Spain) and in MRSA-ID screening medium (bioMérieux). Identification and antibiotic susceptibility was performed by Wider System ^® (Soria Melguizo, S.A., Spain).

Results: We processed 2544 samples (704 A, 963 F, 782 N, and 663 R). 480 of this were from ICU patients. These cultures represent the 11% of all bacteriological cultures received from hospitalised patients in the same period in our laboratory.

113 new patients were colonised or infected by ACI, and 65 of them were detected by SC. Rectal swab was the most useful (51% of 65 patients) followed by faringeal swab (38%). 74% of patients with ACI were from ICU and all but 2 were nosocomial.

In the same year we had 85 new pacients with MRSA, 29% of them were detected in SC. Nasal swab detected 60% of all isolates and faringeal swab 34%. We detected 2 patiens with MRSA at the time of their ICU admittance.

Conclusions: We point out the high work load that screening controls cultures represents for the microbiological laboratory.

The best sample for ACI detection was R, and N was for MRSA. In this setting we found Leeds medium very useful in rectal screening of ACI carriers.

SC were useful in detecting patiens colonised by multirresistant microorganisms in ICU patiens at the time of their admittance