AUTHOR=Bossé Janine T. , Li Yanwen , Fernandez Crespo Roberto , Chaudhuri Roy R. , Rogers Jon , Holden Matthew T. G. , Maskell Duncan J. , Tucker Alexander W. , Wren Brendan W. , Rycroft Andrew N. , Langford Paul R. ,  the BRaDP1T Consortium 

TITLE=ICEApl1, an Integrative Conjugative Element Related to ICEHin1056, Identified in the Pig Pathogen Actinobacillus pleuropneumoniae

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00810

DOI=10.3389/fmicb.2016.00810

ISSN=1664-302X

ABSTRACT=<p>ICE<italic>Apl1</italic> was identified in the whole genome sequence of MIDG2331, a tetracycline-resistant (MIC = 8 mg/L) serovar 8 clinical isolate of <italic>Actinobacillus pleuropneumoniae</italic>, the causative agent of porcine pleuropneumonia. PCR amplification of <italic>virB4</italic>, one of the core genes involved in conjugation, was used to identify other <italic>A. pleuropneumoniae</italic> isolates potentially carrying ICE<italic>Apl1</italic>. MICs for tetracycline were determined for <italic>virB4</italic> positive isolates, and shotgun whole genome sequence analysis was used to confirm presence of the complete ICE<italic>Apl1</italic>. The sequence of ICE<italic>Apl1</italic> is 56083 bp long and contains 67 genes including a Tn<italic>10</italic> element encoding tetracycline resistance. Comparative sequence analysis was performed with similar integrative conjugative elements (ICEs) found in other members of the <italic>Pasteurellaceae</italic>. ICE<italic>Apl1</italic> is most similar to the 59393 bp ICE<italic>Hin1056</italic>, from <italic>Haemophilus influenzae</italic> strain 1056. Although initially identified only in serovar 8 isolates of <italic>A. pleuropneumoniae</italic> (31 from the UK and 1 from Cyprus), conjugal transfer of ICE<italic>Apl1</italic> to representative isolates of other serovars was confirmed. All isolates carrying ICE<italic>Apl1</italic> had a MIC for tetracycline of 8 mg/L. This is, to our knowledge, the first description of an ICE in <italic>A. pleuropneumoniae</italic>, and the first report of a member of the ICE<italic>Hin1056</italic> subfamily in a non-human pathogen. ICE<italic>Apl1</italic> confers resistance to tetracycline, currently one of the more commonly used antibiotics for treatment and control of porcine pleuropneumonia.</p>