β‐glucuronidase activity is an exclusive characteristic of E. coli and some shigellae among Enterobacteriaceae and Vibrionaceae. An agar medium (PGUA agar) which permits the detection of bacteria with β‐glucuronidase activity in mixed cultures was evaluated as a primary culture medium for clinical samples of urine. The medium was selective for enterobacteria and yielded significantly higher recoveries than MacConkey agar. Based on the examination of 3,460 urine samples, it was found that the use of the PGUA agar has several advantages over conventional methods: 1) 94% of all E. coli cultures could be identified on the basis of their appearance on the primary plates; 2) The use of the PGUA method did not result in any misidentifications as compared to 1% of cultures misidentified by the conventional procedure; 3) Approximately one‐half of the urine samples which contained E. coli as the sole organism could be reported following the reading of primary culture plates; 4) The application of the PGUA medium resulted in a 46% reduction in the cost of media employed and a 67% reduction in the time required for the processing of urine samples.

In the period 1969-1974 a decreasing number of Danish hospital departments recorded epidemic occurrences of Staphylococcus aureus strains, and the local spread of strains was less extensive. Multiple-resistant strains of the 83 A complex were succeeded by type 94 strains, resistant to penicillin only. The level of methicillin resistance fell from 19 to 6%. 12% of methicillin resistant strains are now sensitive to streptomycin and/or tetracyclines; they do not represent a few clones, but belong to a wide spectrum of phage types. The changes follow a reduction in the consumption of streptomycin and tetracyclines not of methicillin or other penicillins. As a contrast to the general reduction of combined resistance to streptomycin and tetracyclines, the strains in dermatological departments, where tetracyclines are commonly used, maintain a high degree of resistance to tetracyclines alone.

The paper describes a number of tests for the rapid detection of glycosidases including α‐glucosidase, β‐glucosidase, β‐glucuronidase, β‐xylosidase and α‐fucosidase. The methods use heavy suspensions of viable but non‐multiplying bacteria in a buffered solution of a chromogenic substrate. The results of the tests are readable within 4 h. The application of these tests to a collection of 633 strains of Enterobacteriaceae and Vibrionaceae demonstrates that some of the tests may be valuable additions to the present tests available for the identification of bacteria belonging to these families, β‐glucuronidase activity was observed only in strains of the Escherichia‐Shigella group. 97 per cent of the Escherichia strains possessed β‐glucuronidase activity. β‐xylosidase activity was almost completely restricted to strains of the Klebsiella‐Enterobacter group in addition to Yersinia strains. None of the strains possessed α‐fucosidase activity.

During the years 1966-1974, 167,297 strains isolated from 167,297 patients or staff members in Danish hospitals were registered at Staten Seruminstitu. All the strains were phage-typed and examined for production of a 'Tween'-80-splitting enzyme and resistance to mercuric chloride. 158,236 strains were examined for resistance to antibiotics. Since 1968, a steep decrease in the number of strains resistant to three or more antibiotics (multiple-resistant) and in strains of the 83A complex was noticed. In recent years an increase in strains belonging to phage-group I and in those referred to as miscellaneous and non-identified was registered. The increase in the non-typable strains might be explained by the shift of the concentration of the typing phages from 1000 X RTD to 100 X RTD. It is concluded that at least two factors may have contributed to the reduction of the multiple-resistant strains: an altered antibiotic policy, restricting the use of streptomycin and tetracyclines, and an improved hospital hygiene, diminishing the spread of identical strains within the various departments. However, it is emphasized that the consumption of methicillin is still increasing.

The occurrence of Haemophilus in nasopharyngeal material from 130 hospitalized children aged 0—7 years has been investigated. If a selective medium was used, the carrier rates were very close to 100 per cent. The lowest rate was found in children aged less than one year (78 per cent). Out of a total of 137 Haemophilus strains isolated, H. influenzae amounted to 49 per cent, the remaining 51 per cent were shared between the species H. parainfluenzae, H. haemolyticus and H. parahaemolyticus. V‐factor independent strains were rarely found. The methods used for the determination of the growth‐factor requirements and their importance for the classification of the bacterial strains are discussed. An unclarified but constant finding of antibodies to H. influenzae type d antigen in sera from children aged more than nine months is described. Such antibodies were not found in children below that age, and were rather infrequent in sera from a group of young adults. No correlation was found between the bacteriological findings, the clinical findings and the presence of antibodies to the six H. influenzae types in sera from the children investigated. Thus the investigation does not contribute to the understanding of the clinical significance of any of the Haemophilus species.

The occurrence of Haemophilus in nasopharyngeal material from 130 hospitalized children aged 0—7 years has been investigated. If a selective medium was used, the carrier rates were very close to 100 per cent. The lowest rate was found in children aged less than one year (78 per cent). Out of a total of 137 Haemophilus strains isolated, H. influenzae amounted to 49 per cent, the remaining 51 per cent were shared between the species H. parainfluenzae, H. haemolyticus and H. parahaemolyticus. V-factor independent strains were rarely found. The methods used for the determination of the growth-factor requirements and their importance for the classification of the bacterial strains are discussed. An unclarified but constant finding of antibodies to H. influenzae type d antigen in sera from children aged more than nine months is described. Such antibodies were not found in children below that age, and were rather infrequent in sera from a group of young adults. No correlation was found between the bacteriological findings, the clinical findings and the presence of antibodies to the six H. influenzae types in sera from the children investigated. Thus the investigation does not contribute to the understanding of the clinical significance of any of the Haemophilus species.

Annals of the New York Academy of SciencesVolume 182, Issue 1 p. 21-39 STAPHYLOCOCCI IN DANISH HOSPITALS DURING THE LAST DECADE: FACTORS INFLUENCING SOME PROPERTIES OF PREDOMINANT EPIDEMIC STRAINS Per Bülow M.D., Per Bülow M.D. Department of Medical Bacteriology State Seruminstitute, Kommunehospitalet Aarhus, DenmarkSearch for more papers by this author Per Bülow M.D., Per Bülow M.D. Department of Medical Bacteriology State Seruminstitute, Kommunehospitalet Aarhus, DenmarkSearch for more papers by this author First published: June 1971 https://doi.org/10.1111/j.1749-6632.1971.tb30640.xCitations: 37AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume182, Issue1The Problems of Drug-Resistant Pathogenic BacteriaJune 1971Pages 21-39 RelatedInformation

844 staphylococcal bacteraemia strains out of 2237 were, on re-typing, found to be lysed by the phages 83A, 84, 85, and the two Danish experimental phages 6557‘ and 592’ in various patterns. Evidence is produced which suggests that these strains are related to one another. In the course of time an abbreviation of the phage-patterns has been noticed from 83A/84/85/6557/592 (PST) — 84/85/6557/592 (PSTEN) —“6557” (PSTEM) —“592” (PSTM) caused by lysogenization. It is found that the phage-patterns most frequently encountered are characterized by individual pattern of antibiotic-resistance. It is suggested that the development of resistance depends on a transduction of the property, whereas the accompanying, changes of the phage-patterns are due to a simultaneous lysogenization.

In Staphylococcus aureus strains of type 83A/6557, and in “type 6557” and other group III strains insusceptible to phage 83A, two kinds of temperate phages were frequently found, belonging to the serological group A (α phages) and B (β phages), respectively. The two phages have been characterized by conventional criteria including plaque morphology, serological grouping, host range, and ultrastructure. To meet with the need for more specific identification the following characteristics were included: lysogenic conversion—in casu the ability to convert a positive Tween 80 reaction to a negative one—, ability to block susceptibility to certain typing phages, and kinetics of inactivation with specific anti‐phage sera. These tests were found valuable and may deserve wider application as criteria in phage identification. It is made probable that the β phage has been responsible for the evolution from type 83A/6557 to “type 6557”, due to its ability to block susceptibility to phage 83A. Suggestive evidence is presented for an actual “epidemic” spread of this particular phage within the existing population of susceptible hospital staphylococci, contributing materially to the recently observed change in prevalent epidemic types.

Clinical and bacteriologic findings in about 2000 cases of bacteremia illustrate the changes within the staphylococcal flora in Danish hospitals during the years 1957–66. The phage type complex 52, 52A, 80, 81, usually resistant to penicillin and streptomycin only, regressed with the increasing use of newer antibiotics. It was succeeded by a series of mutually related types of phage Group III, in which resistance to several antibiotics was acquired concomitantly with a stepwise blocking of susceptibility to phage, probably owing to epidemic phage activity. The latest members of the series were often methicillin resistant. The combined effects of lysogenization, transduction and selection affect not only phage type and antibiotic resistance but also properties more directly connected with pathogenicity, such as lipase production, which facilitates the development of boils, and enhances mortality in cases of bacteremia. Development of new staphylococcal types is accelerated in hospitals by abunda...

SUMMARY: Phages capable of changing the production of the ‘Tween’-splitting enzyme by lysogenic conversion of Staphylococcus aureus strains were isolated from lysogenic strains within the phage type 52/52A/80/81 complex.Phages isolated from TW- strains were able to block the production of the ‘Tween’-splitting enzyme when they lysogenized TW+ strains. When the TW+ receptor strains were originally lysogenic, double lysogenization occurred. This change in the ‘Tween’ reaction was shown to be an example of lysogenic conversion. Phages isolated from TW+ strains were found able, in some instances, to change TW- strains to TW+ strains on lysogenization. This change in reaction was found to be due to loss of the converting phage carried by the recipient strains by prophage substitution. Where prophage substitution did not occur and the strains became doubly lysogenic, the strains remained TW-.In these experiments a change of the typing pattern was found after lysogenization. The phage type of the lysogenized strain became similar to that of the donor strain. Non-typable strains were found, doubly lysogenic for phages which between them blocked all the reactions to the typing phages employed. The significance of these findings is discussed, especially the use of lysogenized strains in experiments designed to investigate the role of ‘Tween’ negavity as a virulence factor.

OBSERVATIONS on death or survival of 554 patients with staphylococcal bacteraemia1,2 indicated a correlation between virulence in this situation and the lack of diffusible extracellular lipase as investigated on ‘Tween’/calcium agar plates. Therefore an attempt was made to discover whether the negative lipase reaction was a marker for other properties of the strains, for example, a lowered membrane permeability or a factor inhibiting the lipase or blocking the production of this enzyme.