title: Streptococcus ictaluri sp. nov., isolated from Channel Catfish Ictalurus punctatus broodstock.
abstract: A streptococcal-like organism was associated with diseased Channel Catfish Ictalurus punctatus broodstock on four commercial aquaculture operations in the Mississippi Delta. Conventional biochemical testing, 16S rRNA gene sequence analysis and DNA-DNA hybridization distinguished the isolates from these fish from previously published Streptococcus species. Comparative 16S rRNA gene sequencing studies revealed that the isolates were phylogenetically most similar to Streptococcus iniae, Streptococcus uberis and Streptococcus parauberis with divergence ranging from 2.0 to 2.3 %. Streptococcus pyogenes, Streptococcus urinalis, Streptococcus dysgalactiae subsp. dysgalactiae and Streptococcus canis were included in the analysis and showed even greater differences (2.5-3.2 % divergence). DNA relatedness was 22 % or less to the most phylogenetically related species at the optimal temperature. These data suggest that the isolates represent a novel species of Streptococcus for which the name Streptococcus ictaluri sp. nov. is proposed. The type strain is 707-05(T) (=SO2-1108(T)=ATCC BAA-1300(T)=CCUG 52536(T)).
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: P Lynn
authors.initials: PL
authors.lastname: Shewmaker
authors.affiliation: National Warmwater Aquaculture Center, 127 Experiment Station Road, Stoneville, MS 38776, USA.
authors.forename: Alvin C
authors.initials: AC
authors.lastname: Camus
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Tim
authors.initials: T
authors.lastname: Bailiff
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Arnold G
authors.initials: AG
authors.lastname: Steigerwalt
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Roger E
authors.initials: RE
authors.lastname: Morey
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Maria da Glória S
authors.initials: MDGS
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000382:microbiology*; D020459:Genes, rRNA; D007059:Ictaluridae / Q000382:microbiology*; D008922:Mississippi; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013290:Streptococcal Infections / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S