Open AccessSmooth and Rough Biotypes of Arcanobacterium haemolyticum Can Be Genetically Distinguished at the Arcanolysin Locus
Author(s) -
Haley S. Ruther,
Kalyn Phillips,
Dolores Ross,
Alyssa Crawford,
M. Payton Weidner,
Osama Sammra,
Christoph Lämmler,
David J. McGee
Publication year - 2015
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0137346
Subject(s) - biology , hemolysin , microbiology and biotechnology , insertion sequence , corynebacterium diphtheriae , pathogen , sequence analysis , genetics , gene , virulence , virology , transposable element , genome , vaccination , diphtheria
Arcanobacterium haemolyticum is a Gram-positive, β-hemolytic emerging human pathogen that is classified into smooth or rough biotypes. This bacterial species is also a rare pathogen of animals. Smooth biotypes possess smooth colony edges, are moderate to strong in β-hemolysis, and predominately cause wound infections. In contrast, rough biotypes possess rough and irregular colony edges, have weak to no β-hemolytic activity, and predominately cause pharyngitis. Using horse erythrocytes we confirmed that smooth isolates are generally more hemolytic than rough isolates. A hemolysin from A . haemolyticum , arcanolysin ( aln /ALN), was recently discovered and is a member of the cholesterol-dependent cytolysin (CDC) family. PCR amplification of aln from all 36 smooth A . haemolyticum isolates yielded the expected 2.0 kb product. While 21 rough isolates yielded the 2.0 kb product, 16 isolates had a 3.2 kb product. The extra 1.2 kb segment was 99% identical to IS 911 (insertion sequence) from Corynebacterium diphtheriae . PCR amplification and sequence analysis of the upstream region of aln revealed ~40 nucleotide polymorphisms among 73 clinical isolates from Finland, Denmark, Germany and United States (Nebraska). Remarkably, multi-sequence alignments of the aln upstream region demonstrated that ~90% of the isolates phylogenetically clustered as either smooths or roughs. Differential restriction enzyme analysis of the aln upstream region also demonstrated that the aln upstream region of most (~75%) smooth isolates was cleaved with Cla I while this region in most (~86%) rough isolates was cleaved with Xcm I. We conclude that the aln upstream region can be used to genetically distinguish between smooth and rough biotypes of this important emerging pathogen.