title: Tetracycline Susceptibility in Chlamydia suis Pig Isolates.
abstract: The aims of the present study were to assess the prevalence of Chlamydia suis in an Italian pig herd, determine the tetracycline susceptibility of C. suis isolates, and evaluate tet(C) and tetR(C) gene expression. Conjunctival swabs from 20 pigs were tested for C. suis by real-time polymerase chain reaction, and 55% (11) were positive. C. suis was then isolated from 11 conjunctival swabs resampled from the same herd. All positive samples and isolates were positive for the tet(C) resistance gene. The in vitro susceptibility to tetracycline of the C. suis isolates showed MIC values ranging from 0.5 to 4 μg/mL. Tet(C) and tetR(C) transcripts were found in all the isolates, cultured both in the absence and presence of tetracycline. This contrasts with other Gram-negative bacteria in which both genes are repressed in the absence of the drug. Further investigation into tet gene regulation in C. suis is needed.
authors.affiliation: DIMES, Microbiology, University of Bologna, 40138, Bologna, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Donati
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Balboni
authors.affiliation: University Paris-Est, Anses, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Laroucau
authors.affiliation: University Paris-Est, Anses, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Rachid
authors.initials: R
authors.lastname: Aaziz
authors.affiliation: University Paris-Est, Anses, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Vorimore
authors.affiliation: Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, CH-8057, Zurich, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
authors.affiliation: Parco Nazionale dei Monti Sibillini, Visso, Macerata, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Morandi
authors.affiliation: DIMES, Microbiology, University of Bologna, 40138, Bologna, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Vecchio Nepita
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Di Francesco
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002689:Chlamydia / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D002690:Chlamydia Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D004269:DNA, Bacterial / Q000235:genetics; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012338:RNA, Ribosomal, 23S; D012097:Repressor Proteins; C107173:TetC protein, Bacteria; D013752:Tetracycline