Post by itsybitsyone on May 27, 2008 12:13:07 GMT -8
Persistence of Borrelia burgdorferi Following Antibiotic Treatment in Mice
Antimicrob. Agents Chemother. doi:10.1128/AAC.01050-07
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
aac.asm.org/cgi/content/abstract/AAC.01050-07v1
Emir Hodzic, Sunlian Feng, Kevin Holden, Kimberly J. Freet, and Stephen W. Barthold*
Center for Comparative Medicine, Schools of Medicine and Veterinary Medicine, University of California at Davis, One Shields Avenue, Davis, CA 95616
Abstract
The effectiveness of antibiotic treatment was examined in a mouse model of Lyme borreliosis.
Mice were treated with ceftriaxone or saline for one month, commencing during the early (3 weeks) or chronic (4 months) stages of infection with Borrelia burgdorferi. Tissues from mice were tested for infection by culture, polymerase chain reaction (PCR), xenodiagnosis, and transplantation of allografts at 1 and 3 months after completion of treatment. In addition, tissues were examined for spirochetes by immunohistochemistry.
In contrast to saline-treated mice, mice treated with antibiotic were consistently culture-negative, but tissues from some of the mice remained PCR-positive, and spirochetes could be visualized in collagen-rich tissues.
Furthermore, when some of the antibiotic treated mice were fed upon by Ixodes scapularis ticks (xenodiagnosis), spirochetes were acquired by the ticks, based upon PCR, and ticks from those cohorts transmitted spirochetes to naïve SCID mice, which became PCR-positive, but culture-negative.
Results indicated that following antibiotic treatment, mice remained infected with non-dividing but infectious spirochetes, particularly when antibiotic treatment was commenced during the chronic stage of infection.
Straubinger RK.
2000
PCR-based quantification of Borrelia burgdorferi organisms in canine tissues over a 500-day postinfection period.
Journal of Clinical Microbiology, 38(6):2191-2199
[Persistence:] .Antibiotic treatment resulted in the temporary disappearance of B. burgdorferi DNA. Skin samples became positive by PCR starting 60 days after
treatment had ended, and additional positive samples were detected later. ...therapy with different antibiotics seems to reduce the load of B. burgdorferi infection to
a level of approximately 53 to 13,078 spirochetes per 100 µg of extracted total DNA but fails to eliminate the infection. [Dogs were treated with ceftriaxone,
doxycycline, or azithromycin for 30 consecutive days.]
After antibiotic therapy had ended, in some treated dogs antibody titers remained at constant levels rather than decreasing further. This argues more for the
persistence of the antigenic stimulus than for the complete elimination of B. burgdorferi..
[Diagnosis:] ....DNA of heat-killed borrelia was not detectable for very long in skin tissue of an uninfected dog, implying that during natural infection the DNA of killed
organisms is removed quickly and completely within a few days."
Antimicrob. Agents Chemother. doi:10.1128/AAC.01050-07
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
aac.asm.org/cgi/content/abstract/AAC.01050-07v1
Emir Hodzic, Sunlian Feng, Kevin Holden, Kimberly J. Freet, and Stephen W. Barthold*
Center for Comparative Medicine, Schools of Medicine and Veterinary Medicine, University of California at Davis, One Shields Avenue, Davis, CA 95616
Abstract
The effectiveness of antibiotic treatment was examined in a mouse model of Lyme borreliosis.
Mice were treated with ceftriaxone or saline for one month, commencing during the early (3 weeks) or chronic (4 months) stages of infection with Borrelia burgdorferi. Tissues from mice were tested for infection by culture, polymerase chain reaction (PCR), xenodiagnosis, and transplantation of allografts at 1 and 3 months after completion of treatment. In addition, tissues were examined for spirochetes by immunohistochemistry.
In contrast to saline-treated mice, mice treated with antibiotic were consistently culture-negative, but tissues from some of the mice remained PCR-positive, and spirochetes could be visualized in collagen-rich tissues.
Furthermore, when some of the antibiotic treated mice were fed upon by Ixodes scapularis ticks (xenodiagnosis), spirochetes were acquired by the ticks, based upon PCR, and ticks from those cohorts transmitted spirochetes to naïve SCID mice, which became PCR-positive, but culture-negative.
Results indicated that following antibiotic treatment, mice remained infected with non-dividing but infectious spirochetes, particularly when antibiotic treatment was commenced during the chronic stage of infection.
Straubinger RK.
2000
PCR-based quantification of Borrelia burgdorferi organisms in canine tissues over a 500-day postinfection period.
Journal of Clinical Microbiology, 38(6):2191-2199
[Persistence:] .Antibiotic treatment resulted in the temporary disappearance of B. burgdorferi DNA. Skin samples became positive by PCR starting 60 days after
treatment had ended, and additional positive samples were detected later. ...therapy with different antibiotics seems to reduce the load of B. burgdorferi infection to
a level of approximately 53 to 13,078 spirochetes per 100 µg of extracted total DNA but fails to eliminate the infection. [Dogs were treated with ceftriaxone,
doxycycline, or azithromycin for 30 consecutive days.]
After antibiotic therapy had ended, in some treated dogs antibody titers remained at constant levels rather than decreasing further. This argues more for the
persistence of the antigenic stimulus than for the complete elimination of B. burgdorferi..
[Diagnosis:] ....DNA of heat-killed borrelia was not detectable for very long in skin tissue of an uninfected dog, implying that during natural infection the DNA of killed
organisms is removed quickly and completely within a few days."