A Catheter-Related Candida albicans Infection Model in Mouse

Summary

We establish a mouse model of C.albicans-associated catheter-related infection (CRI), in which biofilm forms on the catheter, and the interaction between C.albicans and host correlates well with the clinical CRI. This model helps screen therapies for C.albicans biofilm-associated CRI, laying a foundation for clinical transformation.

Abstract

Catheter-related infection (CRI) is a common nosocomial infection caused by candida albicans during catheter implantation. Typically, biofilms are formed on the outer surface of the catheter and lead to disseminated infections, which are fatal to patients. There are no effective prevention and treatment management in clinics. Therefore, it is urgent to establish an animal model of CRI for the preclinical screening of new strategies for its prevention and treatment. In this study, a polyethylene catheter, a widely used medical catheter, was inserted into the back of the BALB/c mice after hair removal. Candida albicans ATCC MYA-2876 (SC5314) expressing enhanced green fluorescent protein was subsequently inoculated on the skin's surface along the catheter. Intense fluorescence was observed on the surface of the catheter under a fluorescent microscope 3 days later. Mature and thick biofilms were found on the surface of the catheter via scanning electron microscopy. These results indicated the adhesion, colonization, and biofilm formation of candida albicans on the surface of the catheter. The hyperplasia of the epidermis and the infiltration of inflammatory cells in the skin specimens indicated the histopathological changes of the CRI-associated skin. To sum up, a mouse CRI model was successfully established. This model is expected to be helpful in the research and development of therapeutic management for candida albicans associated CRI.

Introduction

In recent years, with the development and application of biomedical materials, implant-related infections are emerging as difficult clinical problems^1,2. With the wide application of medical catheters in clinics, the number of related infections and deaths is huge every year^3,4. The common infection routes of a catheter-related infection (CRI) include: (1) pathogens on the surface of the skin infiltrate into the body and adhere to the outer surface of the catheter^5,6,

Protocol

Experimental animals, male BALB/c mice (12-16 g), were purchased from the Laboratory Animal Center, Xi'an Jiaotong University Health Science Center. All the procedures were approved by the Institutional Animal Ethical Committee of Xi'an Jiaotong University with the license number SCXK (Shaanxi) 2021-103.

1. Buffer and equipment preparation

1. Transfect C. albicans strains with a high-expression plasmid pCaExp.
   1. Purchase C. albicans.......

Discussion

CRI is one of the most common nosocomial infections in clinical practice²³. Pathogens in the skin appendages, such as the epidermis, sebaceous glands, and hair follicles, are all possible causes of CRI^23,24. Candida is the third largest pathogen that causes CRI, in which Candida albicans was the most common type of biofilm infection^25,26. Therefore, we aimed to bu.......

Materials

Name	Company	Catalog Number	Comments
0.5 Mactutrius turbidibris	Shanghai Lujing Technology Co., Ltd	5106063
2.5% glutaraldehyde fixative solution	Xingzhi Biotechnology Co., Ltd	DF015
4 °C refrigerator	Electrolux (China) Electric Co., Ltd	ESE6539TA
Agar	Beijing Aoboxing Bio-tech Co., Ltd	01-023
Analytical balances	Shimadzu	ATX124
Autoclaves Sterilizer	SANYO	MLS-3750
Butanol	Tianjin Chemio Reagent Co., Ltd	200-889-7
Carbenicillin	Amresco	C0885
Eclipse Ci Nikon upright optical microscope	Nikon	Eclipse Ts2-FL
Glucose	Macklin	D823520
Inoculation ring	Thermo Scientific	251586
Isoflurane	RWD	20210103
Paraformaldehyde	Beyotime Biotechnology	P0099
PAS dye kit	Servicebio	G1285
Peptone	Beijing Aoboxing Bio-tech Co., Ltd	01-001
Polyethylene catheter	Shining Plastic Mall	PE100
RWD R550 multi-channel small animal anesthesia machine	RWD	R550
SEM	Hitachi	TM-1000
Temperature incubator	Shanghai Zhichu Instrument Co., Ltd	ZQTY-50N
Ultrapure water water generator	Heal Force	NW20VF
Ultrasound machine	Do-Chrom	DS10260D
Xylene	Sinopharm  Chemical Reagent Co., Ltd	10023428
Yeast extract	Thermo Scientific Oxoid	LP0021B