Novel selective medium for the isolation of corynebacterium kroppenstedtii from heavily colonised clinical specimens.

Autor: Wong SCY; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Poon RWS; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Foo CH; Department of Microbiology, Queen Mary Hospital, Hong Kong, China., Ngan AHY; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Tse H; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Lam VCM; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Leung THY; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Wong CP; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Cheng VCC; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Chen JHK; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China., Yuen KY; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Jazyk: angličtina
Zdroj: Journal of clinical pathology [J Clin Pathol] 2018 Sep; Vol. 71 (9), pp. 781-786. Date of Electronic Publication: 2018 Mar 28.
DOI: 10.1136/jclinpath-2017-204834
Abstrakt: Aims: Granulomatous mastitis due to Corynebacterium kroppenstedtii is an increasingly recognised cause of an indolent and distressing mastitis in non-lactating females. This slow-growing lipophilic organism is not reliably isolated using routine culture methods. A novel selective culture medium (CKSM) is designed to optimise the isolation of this organism from clinical specimens.
Methods: CKSM contains 10% galactose and Tween 80 (10%) to enhance the growth of C. kroppenstedtii , fosfomycin (100 µg/mL) to suppress the other bacteria, and differentiate C. kroppenstedtii from non- kroppenstedtii lipophilic corynebacteria by esculin hydrolysis. The medium was evaluated for its ability to support the growth of C. kroppenstedtii , selection and differentiation of C. kroppenstedtii from other bacteria in non-sterile clinical specimens.
Results: C. kroppenstedtii grew as 1-2 mm colonies with black halo on CKSM within 72 hours of incubation, compared with barely visible pinpoint colonies on routine blood agars. During the four-month period of evaluation with 8896 respiratory specimens, 103 breast specimens, 1903 female genital tract specimens, 617 newborn surface swabs and 10 011 miscellaneous specimens, 186 C. kroppenstedtii were isolated, including 127 (1.4%) respiratory and 59 (0.5%) miscellaneous specimens, 184 of them were found only on CKSM. Besides the three (2.9%) positive breast specimens, 27 (1.4%) high vaginal and endocervical swabs, and 11 (1.8%) surface swabs of newborns were positive for C. kroppenstedtii .
Conclusions: CKSM is a useful addition to routine agar media for the isolation of C. kroppenstedtii, and will be helpful for studying the epidemiology and transmission of this unusual Corynebacterium causing granulomatous mastitis.
Competing Interests: Competing interests: None declared.
(© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)
Databáze: MEDLINE