1008. Recovery of Multidrug-Resistant Bacteria from Swabs Stored for 1 and 4 Weeks to Mimic Long Distance Shipping Conditions
Session: Poster Abstract Session: Detecting, Identifying, and Typing Bacteria
Saturday, October 22, 2011
Room: Poster Hall B1
Background: Study of healthcare environmental contamination or colonization of patients is difficult in resource poor settings such as deployed combat or humanitarian facilities. Past studies have relied on the use of swabs sent at great distances back to clinical microbiology laboratories for culture, with associated uncertainty of the accuracy of recovery results. To simulate the delays and shipping conditions potentially encountered using this method, we studied the recovery of bacteria from swabs inoculated with multidrug-resistant (MDR) bacteria and stored at 3 temperatures for 1 and 4 weeks.

Methods: BD CultureSwab™ Plus and BD CultureSwab™ MaxV(+) culture swabs were immersed in saline solutions containing 102 or 105 organisms/mL and then stored for 1 day, 1 week, or 4 weeks at 4oC, room temperature (RT), or 45oC. MDR bacteria studied included single strains of Acinetobacter baumannii (Ab), Klebsiella pneumoniae (Kp), E. coli (Ec), Pseudomonas aeruginosa (Ps), and methicillin-resistant Staphylococcus aureus (MRSA). After storage, swabs were streaked onto blood, MacConkey, and CHROMagar S. aureus agar plates, incubated overnight at 35oC, and observed for presence and quantity of growth.

Results: All 5 MDR bacteria were recovered at 1 and 4 weeks. All bacteria were recovered at both concentrations from both swabs stored at RT for 1 and 4 weeks with the exception of low concentration MRSA which was not recovered from Plus swabs. At 45oC, Ab and Ps were not recovered from either swab type at 1 and 4 weeks; MRSA was not recovered at this temperature from Plus swabs. With the exception of Kp from Plus swab at 1 week, MDR bacteria were recovered at 4oC only at the higher concentration at 1 and 4 weeks from both swabs.

Conclusion: MDR bacteria were readily recovered at 1 and 4 weeks when stored at RT. Bacteria were recovered more successfully at the higher concentration at 4oC. Use of MaxV(+) swabs may increase MRSA yield at higher temperatures.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Katrin Mende, PhD1,2, Deena Sutter, MD2, Miriam Beckius, MPH2, Clinton K. Murray, MD2 and Duane Hospenthal, MD, PhD3, (1)Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD, (2)San Antonio Military Medical Center, Fort Sam Houston, TX, (3)San Antonio Military Medical Center, MCHE MDI 7 East, TX


K. Mende, None

D. Sutter, None

M. Beckius, None

C. K. Murray, None

D. Hospenthal, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.