On the effect of the interaction of staphylococcal β toxin and group-B streptococcal substance on red blood corpuscles and its use as a test for the identification ofStreptococcus agalactæ

Streptococcus catagoni sp. nov., isolated from the respiratory tract of diseased Chacoan peccaries (Catagonus wagneri)

Novel catalase-negative, Gram-stain-positive, beta-haemolytic, coccus-shaped organisms were isolated from Chacoan peccaries that died from respiratory disease. The initial API 20 Strep profiles suggested Streptococcus agalactiae with acceptable identification scores, but the 16S rRNA gene similarity (1548 bp) to available sequences of streptococci was below 98 %. Next taxa of the genus Streptococcus, displaying highest similarities to the strains from this study, were S. bovimastitidis NZ1587^T (97.5 %), S. iniae ATCC 29178^T (97.5 %), S. hongkongensis HKU30^T (97.4 %), S. parauberis DSM 6631^T (97.1 %), S. penaeicida CAIM 1838^T (97.1 %), S. pseudoporcinus DSM 18513^T (97.0 %), S. didelphis DSM 15616^T (96.6 %), S. ictaluri 707-05^T (96.6 %), S. uberis JCM 5709^T (96.5 %) and S. porcinus NCTC 10999^T (96.4 %). All other Streptococcus species had sequence similarities of below 96.4 %. A sodA gene as well as whole genome-based core genome phylogeny of three representative strains and 145 available Streptococcus genomes confirmed the unique taxonomic position. Interstrain average nucleotide identity (ANI) and amino acid identity (AAI) values were high (ANI >96 %; AAI 100%), but for other streptococci clearly below the proposed species boundary of 95-96 % (ANI <75 %; AAI <83 %). Results were confirmed by genome-to-genome distance calculations. Pairwise digital DNA-DNA hybridization estimates were high (>90 %) between the novel strains, but well below the species boundary of 70 % for closely related Streptococcus type strains (23.5-19.7 %). Phenotypic properties as obtained from extended biochemical profiles and MALDI-TOF mass spectrometry supported the outstanding rank. Based on the presented molecular and physiological data of the six strains, we propose a novel taxon for which we suggest the name Streptococcus catagoni sp. nov. with the type strain 99-1/2017^T (=DSM 110457^T=CCUG 74072^T) and five reference strains.

416. The effect of bacterial infection on the milk yield of the individual quarters of the cow's udder

A study has been made of the effect of udder infections on the proportionate yield and composition of the milk of individual quarters of over 100 cows, and the data from eleven of these cows have been presented.

Typical examples have been given showing that subclinical Streptococcus and haemolytic Staphylococcus infections may persist for months and either cause a gradual reduction in the proportionate yield, and solids-not-fat percentage of a quarter or have no measurable effect, and that both types of reaction may occur simultaneously in the same udder.

Examples also show that following penicillin treatment of clinical cases caused by streptococci and staphylococci there is little recovery in the proportionate yield of the treated quarter until the following lactation, when recovery may be complete.

Infection with Streptococcus agalactiae in a London hospital

Streptococcus agalactiae is presently the commonest beta-haemolytic streptococcus isolated from clinical material in this hospital. Between October 1974 and March 1975, 81 patients with such infections were seen. Seventeen had urinary tract infections, six had septicaemia, and one neonate had meningitis. Three of those with septicaemia were neonates and two died. The organism was also found to be a cause of pyogenic skin conditions in five patients. Isolates from throat swabs in 12 patients, from sputum in four, and from the female genital tract in 18 were considered part of the normal flora. Human strains of Str. agalactiae were found to be biochemically different from animal strains.

STUDIES WITH STAPHYLOCOCCAL TOXINS: IV. THE PURIFICATION AND METALLIC REQUIREMENTS OF SPECIFIC HEMOLYSINS

A method is described whereby specific staphylococcal hemolysins may be concentrated to provide a 600-fold increase in potency as compared with the initial culture filtrate.The progressive purification of the hemolysins was conveniently followed by the determination of the quantity of hemin (in μg.) freed from a standard suspension of erythrocytes per μg. of protein in the toxic preparation. All preparations of the electrophoretically pure hemolysins were protein in nature, but in order to effect hemolysis, preparations of similar electrophoretic mobility obtained from representatives of two different phage groups (IV and II) showed, respectively, an absolute requirement and no requirement for the presence of specific divalent cations. The initial culture filtrate was dermonecrotic and lethal to test animals. The "purified" hemolysins had neither of these properties.Two "purified" hemolysins that showed differences in biological, electrophoretic, and chemical properties appeared to be serologically homologous. The properties of the "purified" hemolysins from either strain differed from the more generally accepted properties of alpha- and beta-hemolysins even though the culture filtrate seemed to contain these two classically recognized lysins.