Streptococcus ictaluri sp. nov., isolated from Channel Catfish Ictalurus punctatus broodstock.
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)).
Shewmaker
P Lynn
PL
Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Camus
Alvin C
AC
National Warmwater Aquaculture Center, 127 Experiment Station Road, Stoneville, MS 38776, USA.
Bailiff
Tim
T
Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Steigerwalt
Arnold G
AG
Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Morey
Roger E
RE
Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Carvalho
Maria da Glória S
MDGS
Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S