Serological characteristics of coagulase-positive staphylococci isolated from man and animals

A simplified method allowed Staphylococcus aureus, Staph. intermedius and coagulase-positive Staph. hyicus subsp. hyicus isolated from humans, dogs, monkey, sheep, poultry, rabbits, giant rats ( Cricetomys gambianus ) and other animals to be serotyped. The nine coagulase-positive staphylococcal strains of human origin possessed thermolabile and thermostable agglutinogens. Two strains of Staph. intermedius of human and canine origins examined had agglutinogen K₁K₂. The three Staph. aureus strains isolated from African giant rats ( Cricetomys gambianus ) had agglutinogens a₅ and P common to them. The Staph. aureus strain isolated from a monkey belonged to serotype b₁, c₁, o and the caprine strain of Staph. hyicus subsp. hyicus was serotype a₅, c₁.     

Phage typing of the coagulase-positive staphylococci isolated from various species of animals

More than 200 coagulase-positive strains of animal origin have been studied by means of Staphylococcus aureus typing phages, belonging to two international sets and intended for typing staphylococci isolated from large cattle and humans, and experimental "chicken" phage A 1591. Among S. aureus strains the cultures isolated from swine, cows, chickens, and belonging to biotypes B1, C1, B2, respectively, have been mostly (in 78.5-90.0% of cases) determined by phage typing. The strains belonging to one biotype have proved to be sensitive predominantly to the same phages. In this connection further differentiation of staphylococci within individual biotypes by means of the phages used in these experiments seems to be impracticable. S. intermedius strains have been found to be completely resistant to the above phages, which confirms that S. intermedius is rightly considered to be an independent species of coagulase-positive staphylococci.     

Classification and biological characteristics of coagulase-positive Staphylococci isolated from animals

A total of 165 coagulase-positive staphylococcal strains of different origin (142 S. aureus strains and 23 S. intermedius strains) were subjected to biological typing in accordance with the schemes of Hajek-Marsalek and Meyer-Witte. The former of these schemes permitted to identify 68% and the latter 18% of S. aureus strains. The cultures isolated from swine and chickens had the most uniform composition: 85-86% of the strains belonged to biotype B. 44% of the strains isolated from cows and sheep belonged to biotypes C (ecovars bovis and ovis) and A (ecovar hominis); the rest of the strains could not be identified. 96% of the strains isolated from minks were made up of S. intermedius, more than a half of them belonging to biotype E (ecovar canis). In 80% of S. aureus strains and 48% S. intermedius cultures protein A was detected. Only 9% of S. aureus strains of animal origin were found capable of producing enterotoxins (A-D). The expediency of working out a unified scheme for the biotyping of coagulase-positive staphylococci is discussed.     

Characterization of coagulase-positive staphylococci isolated from free-living birds.

A total of 129 coagulase-positive staphylococcal strains were isolated from the nasopharyngeal region of free-living birds--81 (16%) from 501 birds of prey, 29 (25%) from 117 water birds, and 19 (2%) from 937 pheasants. Staphylococcus aureus and Staphylococcus intermedius were identified in 64 (79%) and 17 (21%) strains from birds of prey, in 1 (3%) and 28 (97%) strains from water birds, and in 4 (21%) and 15 (79%) strains from pheasants, respectively. Of the total number of the 69 S.aureus strains 45 (65%) could be biotyped. Biotype D prevailed in the strains from birds of prey. Among all the 60 S.intermedius strains 41 (68%) biotype 1 and 19 (32%) biotype 3 strains could be recognized. Biotype 1 predominated in strains from water birds and pheasants, while biotype 3 in strains from birds of prey. Resistance to antibiotics was recorded in 8 (12%) S.aureus and 5 (8%) S.intermedius strains only. Fifty-six (81%) of the 69 S.aureus strains could be typed with human phages, 30 (44%) with bovine and 41 (51%) with chicken phages. It is evident that the host range of Shimizu's (CH) phages involves not only S.aureus from chicken but also from any other birds. None of these strains was typable with canine phages. Out of the 60 S.intermedius strains 45 (75%) were lysed with Blouse and Meekins' canine phages. When human, bovine, and chicken phages were used, all the 60 strains were completely resistant.     

Characteristics of staphylococci isolated from man, poultry and some other animals

Of 281 strains of staphylococci isolated from man and animals 36 (12–8%) were coagulase-positive and 245 (87–2%) were coagulase-negative. Staphylococcus aureus and Staph. intermedius were the commonest coagulase-positive staphylococci isolated from the hosts examined. Of the 20 strains that remained unclassifiable, 14 were isolated from sheep and goats.     

Characteristics of staphylococci isolated from man, poultry and some other animals

Of 281 strains of staphylococci isolated from man and animals 36 (12.8%) were coagulase-positive and 245 (87.2%) were coagulase-negative. Staphylococcus aureus and Staph. intermedius were the commonest coagulase-positive staphylococci isolated from the hosts examined. Of the 20 strains that remained unclassifiable, 14 were isolated from sheep and goats.     

Antagonistic activities of coagulase-positive staphylococci

Antagonistic activities were investigated by Frédérioq's plate method in 1,014 coagulase-positive staphylococcal strains of different species and origins. Staphylococcin effect was demonstrated in 12 (2%) of the 559 Staphylococcus aureus strains, in 51 (18%) of the 283 S. intermedius strains, and in 1 (3%) of the 36 S. hyicus subsp. chromogenes strains. Lysostaphin was identified in the 15 (5%) S. intermedius strains. In addition, heat-stable bacteriostatic agent was detected in 45 (33%) and heat-labile bacteriolytic agent in 7 (5%) of the 136 S. hyicus subsp. hyicus strains. An attempt was made at antagonistic activity typing in all of the active staphylococcal strains.     

A comparative immunological study of catalases from coagulase-positive staphylococci

Protein homology studies with catalase as a reference point were carried out with coagulasepositive staphylococci belonging to Staphylococcus aureus, S. intermedius and S. hyicus. Antisera against catalases of S. aureus ATCC 12600 and S. aureus ATCC 12601 reacted very weakly employing double immunodiffusion and quantitative microcomplementfixation assay with cell-free extracts or catalase enriched preparations of S. intermedius or S. hyicus. The differences between coagulase-positive staphylococci could be confirmed by using the antiserum against S. intermedius H 11 catalase. Within the strains of the species S. intermedius immunological distances ranging up to 25 indicate a heterogeneity which justify the separation of the biotypes E and F on a subspecies level. Coagulase-positive strains of S. hyicus revealed neither a close relationship to S. aureus nor to S. intermedius.     

Comparative study of apramycin-resistant microorganisms isolated from man and animals

Apramycin-modifying strains isolated from pigs with coli bacteriosis, from humans and hospital environment were studied comparatively. Production of enzymes modifying the aminoglycoside was estimated with the radioactive cofactor procedure. E. coli isolates from the animals were phenotypically resistant to apramycin and a number of other aminoglycosides. They produced acetyltransferase AAC(3)IV, phosphotransferase APH(3')(5"), APH(3") and other enzymes. Resistance of the strains to gentamicin was also conditioned by AAC(3)IV since these strains did not produce AAD(2") and AAC(6'). In the resistant strains of E. coli and their transconjugates there were detected plasmids with a relative molecular weight of 60-80 MD. Some of the belonged to the compatibility group I1, the others belonged to the compatibility group H1. Strains of S. marcescens, K. pneumoniae. K. oxytoca and S. aureus isolated from humans and hospital environment were sensitive to apramycin. Only isolates of P. aeruginosa were resistant to this antibiotic. However, all the isolates produced AAC(3)IV. Some of them additionally produced AAC(6'), an enzyme modifying amikacin, kanamycin and other antibiotics and not acetylating apramycin. Almost all the strains produced kanamycin- and streptomycin phosphotransferases. Possible coselection of strains resistant to apramycin and gentamicin using one of these aminoglycosides is discussed.     

Serological identification of enterotoxigenic staphylococci from cheese

Single and double gel-diffusion techniques were employed to examine serologically coagulase-positive staphylococci from cheese for enterotoxigenicity. Supernatant fluid from sac cultures was examined for enterotoxins A and B. The results indicated that 9 of 155 cultures from market cheese and 7 of 77 cultures from food-poisoning cheese produced enterotoxin A, and that none of the cultures produced detectable levels of enterotoxin B. Results of serological tests were confirmed by intravenous injection of cats.     

Deoxyribonucleic acid reassociation in the classification of coagulase-positive staphylococci

DNA-DNA reassociation studies were performed with coagulase-positive staphylococci belonging to the biotypes A, B, C, D, E and F. These studies present genetic evidence for the existence of at least two distinct species within this group of organisms. The common Staphylococcus aureus strains were represented by organisms from biotypes A to D, and their DNA revealed over 80% nucleotide sequence homology under restrictive conditions. Less than 15% DNA homology was detected between strains from biotypes A to D (S. aureus) and those from biotypes E and F. The DNA of organisms from either the biotypes E or F displayed over 70% homology. Together, both biotypes are considered to represent the species S. intermedius. However, DNA homology values dropped to 50–65% between strains from different biotypes. This may justify the separation of S. intermedius biotypes E and F on a subspecies level.Abbreviations O.D. optical density - SSC standard saline citrate buffer (0.15 M NaCl, 0.015 M sodium citrate, pH 7.0) This work was supported by Deutsche Forschungsgemeinschaft     

Chemical and biochemical studies for the differentiation of coagulase-positive staphylococci

The cell wall composition, the configuration of lactic acid produced from glucose under anaerobic conditions, the occurrence of fructose-1,6-diphosphate (FDP) activatedl-lactate dehydrogenase (l-LDH), and the esterase pattern were determined from more than 80 strains of coagulase-positive staphylococci isolated from man and animal. Strains isolated from man, swine, bovines and hares form a rather homogencous group. They exhibit a similar cell wall composition, produce predominantlyd,l-lactate and have a characteristic and simple esterase pattern. Coagulasepositive staphylococci isolated from dogs, horses, minks and pigeons are quite distinct from typicalStaphylococcus aureus strains. They exhibit a different cell wall composition, produce onlyl-lactate, possess anl-LDH which is specifically activated by FDP, and have a quite complex esterase pattern.List of Abbreviations BBP bromphenol blue - FDP fructose-1,6-diphosphate - d-LDH d-lactate dehydrogenase - l-LDH l-lactate dehydrogenase - NAD nicotinamide adenine dinucleotide