Borrelia burgdorferi

Samuels Lab: Working with Borrelia burgdorferi

Last updated: May 3, 2017

Introduction

Borrelia burgdorferi is the causative agent of Lyme disease.  We do extensive recombinant DNA research with Escherichia coli and B. burgdorferi, including recombinant B. burgdorferi in ticks and mice (NIH Guidelines Section III-D).  B. burgdorferi is classified as a Risk Group 2 Bacterial Agent (NIH Guidelines Appendix B-II-A) and is handled at BSL-2, although there have never been any reported cases of laboratory infections.  Please see our Biosafety SOP for more details.    

Safety Procedures for Handling in the Laboratory

Biohazard signs are posted on the entry door to the laboratory (Clapp 211) and the entry door to the culture room (Clapp 208) inside the laboratory.  The entry door to the laboratory is kept locked when experiments are in progress.  All personnel wear a lab coat and gloves when handling infectious material. Infectious material is handled in the BSC (in Clapp 208).  Sharps use is discouraged, but disposed of in approved sharps containers when use is necessary.  General disposables are placed in autoclave hazard bags into which a 3M Comply SteriGauge has been placed so as to be readable after autoclaving; bags are loosely closed with tape before autoclaving.  Autoclaving is at 121°C for 1 h; autoclave tape and integrator strips are checked to assure sufficient sterilization time.  Sterilized waste is disposed of in the regular trash after biohazard marking is deleted or defaced.  Biohazard signs are posted on all BSCs and incubators.  BSC is disinfected before and after use with 70% ethanol.  Hands are washed after removing gloves. 


Safety Procedures for Handling in the Animal Facility

Biohazard signs are posted on the entry door to HSB 004 and on the cubicle where the animal work is conducted.  All personnel wear a lab coat and gloves when working with animals.  B. burgdorferi remains in the animal for the 5 weeks following infection.

A.  All ticks will be collected at the end of experiments and placed in a screw top conical tube and autoclaved. 

B.  All cages and equipment that have at one time come in contact with ticks will be autoclaved.  Also, mice infested with ticks will be euthanized and the carcass autoclaved.

C.  Carcass storage is in freezer in HSB 015.  Carcasses will be collected by Environmental Health and Risk Management for final disposal.

D.  A cage with a mesh-wire bottom is placed above a pan filled with water and will house one mouse while ticks are allowed to feed.  The pan and cage are then placed in a rat cage with the bottom filled with water.  A barrier of petroleum jelly and double-sticky-sided tape is then placed around the inside of the top of the rat cage.  Feeding is for less than one week.

D.  Procedure if a tick is found in HSB 004: collect the tick in a tightly sealed container (screw cap plastic tube, vial, zip-lock bag).  Contact Dan Drecktrah or Laura Hall at x6341 to screen the tick for the presence of B. burgdorferi.   

We also put strips of sticky mat around the door of the cubicle in addition to the layers of double-sticky-sided tape and petroleum jelly around the cages.  LAR staff need not enter cubicle C as food and water are changed by laboratory personnel during the 6 days of tick feeding, thus minimizing exposure to B. burgdorferi-infected ticks.  Ticks will never leave cubicle C during mouse-feeding experiments.  These measures are prudent and should minimize the exposure of researcher personnel and LAR staff to B. burgdorferi-infected ticks.

Accidental Spill or Exposure

Protective clothing including laboratory coats and gloves must be worn.  All spills of live cultures will be treated with bleach (1% sodium hypochlorite) or Rescue RTU and gently covered with paper towels, starting at perimeter and working towards the center of the spill.  Paper towels will then be collected into biohazard bags, sealed, and steam sterilized in an autoclave.  Biohazard markings on the bag will be deleted following sterilization.

The transmission of B. burgdorferi requires a tick vector and we are working with infected ticks, which presents a risk to laboratory personnel.  However, the incidental transmission of B. burgdorferi to humans in the laboratory resulting in Lyme disease has never been reported.  Currently, there is no human vaccine available.  Transmission by aerosol inhalation, ingestion, or skin-to-skin contact has also never been reported and seems unlikely.  However, in the event of a laboratory-acquired infection, treatment of Lyme disease is by antibiotic therapy based on guidelines from the Infectious Diseases Society of America (IDSA): "For prevention of Lyme disease after a recognized tick bite…. A single dose of doxycycline may be offered to adult patients (200 mg dose)…when all of the following circumstances exist: (a) the…tick…is estimated to have been attached for >36 h on the basis of the degree of engorgement of the tick with blood or of certainty about the time of exposure to the tick; (b) prophylaxis can be started within 72 h of the time that the tick was removed;…[and] (c)…doxycycline treatment is not contraindicated." Otherwise: "Doxycycline (100 mg twice per day), amoxicillin (500 mg 3 times per day), or cefuroxime axetil (500 mg twice per day) for 14 days (range, 10–21 days for doxycycline and 14–21 days for amoxicillin or cefuroxime axetil) is recommended for the treatment of adult patients with early localized or early disseminated Lyme disease….Patients who are intolerant of, or should not take, amoxicillin, doxycycline, and cefuroxime axetil…recommended dosage regimens for macrolide antibiotics are as follows: azithromycin, 500 mg orally per day for 7–10 days; clarithromycin, 500 mg orally twice per day for 14–21 days (if the patient is not pregnant); or erythromycin, 500 mg orally 4 times per day for 14–21 days" (Wormser et al., 2006, The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America, Clin. Infect. Dis. 43:1089-1134).  The Occupational Health physician at Curry HS may be contacted to write the prescription for antibiotics.