Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Feb 25;11(2):e0149914.
doi: 10.1371/journal.pone.0149914. eCollection 2016.

Tetracycline Susceptibility in Chlamydia suis Pig Isolates

Manuela Donati  1 , Andrea Balboni  2 , Karine Laroucau  3 , Rachid Aaziz  3 , Fabien Vorimore  3 , Nicole Borel  4 , Federico Morandi  5 , Edoardo Vecchio Nepita  1 , Antonietta Di Francesco  2
Affiliations

Tetracycline Susceptibility in Chlamydia suis Pig Isolates

Manuela Donati et al. PLoS One. .

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.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. TetR(C)-tet(C) region of the Eu-21 Chlamydia suis isolate compared with the same genomic region of the R19 and R27 C. suis strains.
The highlighted alignment shows the eight-nucleotide sequence deleted in R19 and R27 C. suis strains.
Fig 2
Fig 2. Analysis of tetR(C) transcription in Eu-22 and Eu-21 Chlamydia suis isolates.
Lanes 1 and 2: tetR(C) transcript from Eu-22 in the absence and presence of tetracycline at a concentration of 0.25 μg/mL. Lanes 3 and 4: tetR(C) transcript from Eu-21 in the absence and presence of tetracycline at a concentration of 0.25 μg/mL. Lane 5: negative control using NB-1 C. suis isolate cultured in the absence of tetracycline. Lane 6: blank control of RNA extraction. Lane 7: blank control of reverse transcription. Lane 8: blank control of PCR. Lane 9: positive control using bacterial genomic DNA as a template. Lane 10: BenchTop Markers (Promega, Madison, WI, USA).
Fig 3
Fig 3. Analysis of tet(C) transcription in Eu-22 and Eu-21 Chlamydia suis isolates.
Lanes 1 and 2: tet(C) transcript from Eu-22 in the absence and presence of tetracycline at a concentration of 0.25 μg/mL. Lanes 3 and 4: tet(C) transcript from Eu-21 in the absence and presence of tetracycline at a concentration of 0.25 μg/mL. Lane 5: negative control using NB-1 C. suis isolate cultured in the absence of tetracycline. Lane 6: blank control of RNA extraction. Lane 7: blank control of reverse transcription. Lane 8: blank control of PCR. Lane 9: positive control using bacterial genomic DNA as a template. Lane 10: BenchTop Markers (Promega, Madison, WI, USA).
See this image and copyright information in PMC

References

    1. Schautteet K, Vanrompay D. Chlamydiaceae infections in pig. Vet Res. 2011;42: 29 10.1186/1297-9716-42-29 . - DOI - PMC - PubMed
    1. Andersen AA, Rogers DG. Resistance to tetracycline and sulfadiazine in swine C trachomatis isolates, 1998, p. 313–316. In R. S. Stephens (ed.), Chlamydial infections. Proceedings of the Ninth International Symposium on Human Chlamydial Infection. International Chlamydia Symposium, San Francisco, CA.
    1. Dugan J, Rockey DD, Jones L, Andersen AA. Tetracycline resistance inChlamydia suis mediated by genomic islands inserted into the chlamydial inv-like gene. Antimicrob Agents Chemother. 2004;48(10): 3989–3995. . - PMC - PubMed
    1. Sandoz KM, Rockey DD. Antibiotic resistance in Chlamydiae. Future Microbiol. 2010;5(9): 1427–1442. 10.2217/fmb.10.96 . - DOI - PMC - PubMed
    1. Di Francesco A, Donati M, Rossi M, Pignanelli S, Shurdhi A, Baldelli R et al. (2008) Tetracycline resistant Chlamydia suis isolates, in Italy. Vet Rec. 2008;163(8): 251–252. . - PubMed

MeSH terms