title: Weakly beta-haemolytic human intestinal spirochaetes antagonize the haemolytic activity of Clostridium perfringens alpha-toxin producer.
abstract: The production of haemolytic antagonism between weakly beta-haemolytic human intestinal spirochaetes (wbetaHIS) related to human intestinal spirochaetosis and Clostridium perfringens alpha-toxin producer was investigated. A reduction of the clostridial haemolytic activity and a distortion of the haemolytic halo of clostridial alpha-toxin surrounded by a small zone of poorly cooperative haemolysis was clearly observed on the level of the spirochaetal growth area when 40 out of 41 wbetaHIS were cultivated in sheep blood agar plates together with Clostridium perfringens alpha-toxin producer. This phenomenon of haemolytic antagonism was observed only when wbetaHIS grew 72-96 hours sooner than C. perfringens and after the inoculum of the latter at a distance of 0 to 10 mm from wbetaHIS the plates were anaerobically incubated for an additional 48 hours and the bacteria were used at concentrations ranging from 10(7) to 10(4) CFU/ml. These results were also observed between C. perfringens and weakly beta-haemolytic intestinal spirochaetes related to animal intestinal spirochaetosis including avian strains and Brachyspira (Serpulina) pilosicoli of porcine origin.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Parma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Calderaro
authors.forename: G
authors.initials: G
authors.lastname: Dettori
authors.forename: R
authors.initials: R
authors.lastname: Grillo
authors.forename: P
authors.initials: P
authors.lastname: Cattani
authors.forename: P
authors.initials: P
authors.lastname: Ragni
authors.forename: R
authors.initials: R
authors.lastname: Guégan
authors.forename: G
authors.initials: G
authors.lastname: Fadda
authors.forename: C
authors.initials: C
authors.lastname: Chezzi
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism; D001717:Birds / Q000382:microbiology; D001773:Blood Cells / Q000382:microbiology; D002135:Calcium-Binding Proteins; D003015:Clostridium Infections / Q000382:microbiology; D003016:Clostridium perfringens / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*; D006461:Hemolysis; D006462:Hemolytic Plaque Technique; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D012756:Sheep; D013144:Spirochaetales / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D013145:Spirochaetales Infections / Q000382:microbiology; D013552:Swine / Q000382:microbiology; D013997:Time Factors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D002135:Calcium-Binding Proteins; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens