title: More than fishing in the dark: PCR of a dispersed sequence produces simple but ultrasensitive Wolbachia detection.
abstract: BACKGROUND
  Detecting intracellular bacterial symbionts can be challenging when they persist at very low densities. Wolbachia, a widespread bacterial endosymbiont of invertebrates, is particularly challenging. Although it persists at high titers in many species, in others its densities are far below the detection limit of classic end-point Polymerase Chain Reaction (PCR). These low-titer infections can be reliably detected by combining PCR with DNA hybridization, but less elaborate strategies based on end-point PCR alone have proven less sensitive or less general.
  
  
  RESULTS
  We introduce a multicopy PCR target that allows fast and reliable detection of A-supergroup Wolbachia--even at low infection titers--with standard end-point PCR. The target is a multicopy motif (designated ARM: A-supergroup repeat motif) discovered in the genome of wMel (the Wolbachia in Drosophila melanogaster). ARM is found in at least seven other Wolbachia A-supergroup strains infecting various Drosophila, the wasp Muscidifurax and the tsetse fly Glossina. We demonstrate that end-point PCR targeting ARM can reliably detect both high- and low-titer Wolbachia infections in Drosophila, Glossina and interspecific hybrids.
  
  
  CONCLUSIONS
  Simple end-point PCR of ARM facilitates detection of low-titer Wolbachia A-supergroup infections. Detecting these infections previously required more elaborate procedures. Our ARM target seems to be a general feature of Wolbachia A-supergroup genomes, unlike other multicopy markers such as insertion sequences (IS).
authors.forename: Daniela I
authors.initials: DI
authors.lastname: Schneider
authors.forename: Lisa
authors.initials: L
authors.lastname: Klasson
authors.forename: Anders E
authors.initials: AE
authors.lastname: Lind
authors.affiliation: Laboratory of Genome Dynamics, Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Waehringerstrasse 10, Vienna 1090, Austria. wolfgang.miller@meduniwien.ac.at.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Miller
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D004330:Drosophila / Q000382:microbiology / Q000502:physiology; D006927:Hymenoptera / Q000382:microbiology / Q000502:physiology; D020071:Interspersed Repetitive Sequences; D016133:Polymerase Chain Reaction / Q000379:methods*; D013559:Symbiosis; D014370:Tsetse Flies / Q000382:microbiology / Q000502:physiology; D020577:Wolbachia / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D004269:DNA, Bacterial