Chloramphenicol acetyltransferase as a selection marker for chlamydial transformation.
BACKGROUND
Chlamydia is a common bacterial pathogen responsible for many diseases. Methods for transforming this important organism using a β-lactamase as a selection marker have been developed very recently. However, the National Institutes of Health Guidelines for Research Involving Recombinant DNA Molecules do not permit transformation experiments with β-lactamase gene-containing vectors for certain human chlamydial pathogens. Therefore, a different selection marker is urgently needed for transformation of those chlamydiae.


RESULTS
After transformation of plasmid-free Chlamydia trachomatis with pGFP:SW2, which carries a β-lactamase and a chloramphenicol acetyltransferase gene fused to a green fluorescence protein gene, transformants were obtained by selection with either ampicillin or chloramphenicol. Stable chloramphenicol-resistant, but ampicillin-sensitive, transformants were obtained using a pGFP:SW2 derivative without the β-lactamase. All transformants expressed green fluorescence protein and had glycogen synthesis activity restored.


CONCLUSIONS
Chloramphenicol resistance may be used as a selection marker for genetic experiments in Chlamydia. This eliminates the requirement for the use of β-lactamase, of which dissemination to some C. trachomatis serovars may jeopardize clinical treatment of chlamydial infections in pregnant women. Chloramphenicol acetyltransferase may also serve as a useful secondary selection marker for genetic analyses in β-lactamase-transformed chlamydial strains.
Department of Pharmacology, Rutgers University Robert Wood Johnson Medical School, Piscataway, NJ, USA. huizhou.fan@rutgers.edu.
Shuang
S
Xu
Lauren
L
Battaglia
Xiaofeng
X
Bao
Huizhou
H
Fan
D002692:Chlamydia trachomatis / Q000201:enzymology* / Q000235:genetics*; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism*; D005260:Female; D005819:Genetic Markers; D006003:Glycogen / Q000096:biosynthesis; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D010957:Plasmids / Q000378:metabolism; D011247:Pregnancy; D014170:Transformation, Genetic
D005819:Genetic Markers; D049452:Green Fluorescent Proteins; D006003:Glycogen; D015500:Chloramphenicol O-Acetyltransferase