2056. Significance of Imipenem Tolerance in Cases of Respiratory Tract Infection caused by Pseudomonas aeruginosa.
Session: Poster Abstract Session: Antimicrobial Resistant Infections: Treatment
Saturday, October 29, 2016
Room: Poster Hall
Background: MIC is commonly used in clinical settings. Although a low MIC indicates high drug sensitivity, treatment-resistant cases, despite their good sensitivity according to their MIC, are often encountered. Tolerance is defined as a state in which the MBC deviates from the MIC. MIC signifies the minimum drug concentration required to prevent the growth of bacteria in vitro, whereas MBC denotes the minimum drug concentration required to kill bacteria in vitro.In the present study, we used clinical isolates from sputum samples to investigate the correlation between clinical tolerance and pathology of respiratory illnesses.

Methods: We examined a total of 63 strains isolated from the respiratory apparatus samples of the different patients and conducted a retrospective investigation of the medical records of 15 patients who were determined to exhibit P. aeruginosa sensitivity. They were divided into high-tolerance MBCAD/MICAD (Over 32; n=9) and low-tolerance MBCAD/MICAD(Under 8; n=6) groups for further investigation.

Results: The findings indicated that the high-tolerance group included many severe cases with respiratory failure, and the imaging results showed that the disease was more extensive. Comparison of the bacterial basic data, high-tolerance group significantly upregulated the biofilm formation, elastase productions, pyoverdine production, swimming motility and swarming motility compared to low-tolerant group.

Conclusion: Conclusion: The present study clarified that the high-tolerance group comprised many patients with respiratory failure and refractory cases. Thus, tolerance level could be a prognostic marker for the chronic infection of P. aeruginosa, and furthermore, the development of a mechanism to suppress tolerance induction could be a target issue for new drugs to inhibit the progression of persistent P. aeruginosa infection.

Momoyo Azuma, MD, PhD1,2, Keiji Murakami, MD, PhD3, Yoichiro Miyake, MD, PhD3 and Yasuhiko Nishioka, MD, PhD2, (1)Department of Infection Control, Tokusihma University hospital., Tokushima, Japan, (2)Department of Respiratory Medicine and Rheumatology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan, (3)Department of Oral Microbiology, Institute of Health Biosciences, Tokushima University Graduate School., Tokushima, Japan


M. Azuma, None

K. Murakami, None

Y. Miyake, None

Y. Nishioka, None

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