The Listeria transcriptional landscape from saprophytism to virulence.
The bacterium Listeria monocytogenes is ubiquitous in the environment and can lead to severe food-borne infections. It has recently emerged as a multifaceted model in pathogenesis. However, how this bacterium switches from a saprophyte to a pathogen is largely unknown. Here, using tiling arrays and RNAs from wild-type and mutant bacteria grown in vitro, ex vivo and in vivo, we have analysed the transcription of its entire genome. We provide the complete Listeria operon map and have uncovered far more diverse types of RNAs than expected: in addition to 50 small RNAs (<500 nucleotides), at least two of which are involved in virulence in mice, we have identified antisense RNAs covering several open-reading frames and long overlapping 5' and 3' untranslated regions. We discovered that riboswitches can act as terminators for upstream genes. When Listeria reaches the host intestinal lumen, an extensive transcriptional reshaping occurs with a SigB-mediated activation of virulence genes. In contrast, in the blood, PrfA controls transcription of virulence genes. Remarkably, several non-coding RNAs absent in the non-pathogenic species Listeria innocua exhibit the same expression patterns as the virulence genes. Together, our data unravel successive and coordinated global transcriptional changes during infection and point to previously unknown regulatory mechanisms in bacteria.
Toledo-Arana
Alejandro
A
Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.
Dussurget
Olivier
O
Nikitas
Georgios
G
Sesto
Nina
N
Guet-Revillet
Hélène
H
Balestrino
Damien
D
Loh
Edmund
E
Gripenland
Jonas
J
Tiensuu
Teresa
T
Vaitkevicius
Karolis
K
Barthelemy
Mathieu
M
Vergassola
Massimo
M
Nahori
Marie-Anne
MA
Soubigou
Guillaume
G
Régnault
Béatrice
B
Coppée
Jean-Yves
JY
Lecuit
Marc
M
Johansson
Jörgen
J
Cossart
Pascale
P
D000818:Animals; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D016680:Genome, Bacterial / Q000235:genetics; D007422:Intestines / Q000382:microbiology; D008089:Listeria monocytogenes / Q000235:genetics* / Q000472:pathogenicity*; D051379:Mice; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D012329:RNA, Bacterial / Q000032:analysis / Q000235:genetics*; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*; D020506:Untranslated Regions / Q000235:genetics; D014774:Virulence / Q000235:genetics
D012329:RNA, Bacterial; D038621:Regulatory Sequences, Ribonucleic Acid; D020506:Untranslated Regions