SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Samonella typhimurium bacteriophage type 505 is the most frequently encountered phage type in the Netherlands and its neighboring countries. Phage type 505 was analyzed with regard o the interference with propagation of the typing phages by the prophages and plasmids, present in the type strain S. typhimurium 505...
Bacteriophage types of over 3,000 strains of Corynebacterium diphtheriae isolated in Canada have been determined. The typing scheme used involved the use of nine phages. Results indicated that phage types correlate with biotypes to a large degree. Corynecin types were also determined for a limited number of cultures, and results indicated that the indicator strains presently available are unsuitable for the typing of C. diphtheriae strains isolated in North America. The distribution of phage types is similar throughout Canada, and the types present correspond to types reported from other countries. Phage typing could be of value in the study of circumscribed outbreaks and in epidemiological surveillance of types over long periods.
Data are presented concerning the study of the phage type of Sh. sonnei isolated in various regions of the USSR. The strains isolated belonged to 64 phage types corresponding to the Hammarström's scheme. A variety of Shigella sonnei phage types both in one and in different territories of the country provided future prospects for successful use of phage typing for the purpose of epidemiological supervision and analysis of dysentery morbidity.
A provisional typing schema based on sensitivity to 23 bacteriophages has been established for Proteus mirabilis. Seventy-three bacteriophages were isolated on strains of P. mirabilis (64), P. vulgaris (1), P. morganii (7), and P. rettgeri (1), but those isolated on P. mirabilis were the most useful in differentiating other strains of . mirabilis. From the 73 phages studied, the best 23 were chosen by computer analysis for the provisional system, which was then used to study P. mirabilis infections in a 500-bed general hospital. All patient isolates for 19 months were saved and then compared by bacteriophage typing and the Dienes reaction in a retrospective study. There was evidence for only three instances of cross-infection or -colonization during this time. Bacteriophage typing was very sensitive in differentiating strains, since 200 strains were differentiated into 113 different lysis patterns and 94% were typable. The Dienes reaction was useful at times but often gave reactions that were difficult to read or that changed when the tests were repeated. The bacteriophages described by Schmidt and Jeffries were also evaluated and proved useful in combination with ours. The value of bacteriophage typing was clearly established, and work toward a standardized schema for P. mirabilis should continue.
A bacteriophage-typing schema was developed for differentiating strains of Shigella sonnei. Sixty-seven bacteriophages were obtained from other collections, and 36 bacteriophages were isolated from sewage. From these 103 bacteriophages, a provisional set of 12 was chosen by computer analysis as being the most sensitive in differentiating strains of S. sonnei isolated in the United States. The provisional schema was used to type 265 strains from different geographical areas. It divided them into 87 different lysis patterns, and all 265 strains were typable. Smooth and rough colonial variants of the same strain had different lysis patterns, so the technique was standardized to type rough colonies only. Reproducibility was difficult to obtain until all conditions were carefully standardized. Changes in results were noted even on different lot numbers of Trypticase soy agar, which was defined as the standard medium. So that the medium would not be a variable, 100 pounds (ca 453.5 kg) of the same lot number was purchased. Bacteriophage typing was very useful in differentiating strains, and work should continue on establishing a standarized schema.
Cultures comprising the 10 species of coagulase-negative staphylococci proposed by Kloos and Schleifer (J. Clin. Microbiol. 1:82--88, 1975) were typed with bacteriophages isolated from Staphylococcus epidermidis. Although only 10.5% were typable, 50% of those identified as S. epidermidis were typed. Cultures from patients with middle ear infections were also classified by this system and phage typed.
A bacteriophage typing system is described for Salmonella infantis. Nine phages were selected, of which three were isolated from sewage and six from human feces. All except 7 of the 546 strains collected between 1974 and 1978 could be classified into 23 different phage types. The five most common phage types comprised 26, 13, 9, 9, and 9% of all strains, respectively. Strains from humans, animals, food, and water isolated during nine episodes, or from given patients at different intervals of time, belonged to the same phage type.
The bacteriophage typing of 54 strains isolated from the tissues of mice infected with the strain H37Rv of Mycobacterium tuberculosis and treated with isonazid and rifampin showed that the bacteriophage type did not change. The fluctuation analysis of populations of the tubercle bacilli demonstrated that the rate of mutation from sensitivity to resistance in respect to the bacteriophage DS6A was less than 1.3 X 10(-8) mutations per bacterium per generation.
Bacteriophage typing was used to subdivide Klebsiella obtained from patients in a surgical intensive care unit during a 2-year period. The 15 phages employed to type the strains were propagated by a soft-agar layer technique. In all, 23 phage types were found among the 120 clinical strains. The phage types of repeat isolates were reproducible. Only 70% of the strains tested were phage typable, but when used in conjunction with capsular serotyping and biotyping, a much greater subdivision of the Klebsiella strains was achieved. The addition of phage typing to serobiotyping for epidemiological analysis suggested that the number of cross-infecting Klebsiella strains in the intensive care unit was few, but that these strains persisted in the unit for long periods of time and could infect different body sites.
Strains of Mycobacterium tuberculosis were obtained from 65 patients with pulmonary tuberculosis resident in Uganda, and from pulmonary and extrapulmonary tuberculosis in 42 British patients of European ethnic stock and in 67 Asian immigrants, often from Uganda, resident in Britain. The bacteriophage-type patterns of the African, British and Asian strains were different. The pattern for the Asian strains resembled that found previously in patients from South India, suggesting that there has been little interchange of organisms between the Asian community and the African and British communities alongside whom they have lived. The patterns for pulmonary and extra-pulmonary tuberculosis were similar. Strains of bacteriophage type 1, mainly obtained from Asians, were characterized by a greater susceptibility to the bactericidal activity of hydrogen-peroxide and/or a greater sensitivity to thiophen-2-carbonic acid hydrazide than strains of other types.
A procedure in which soft agar overlays were used in bacteriophage-typing Mycobacterium tuberculosis is presented. This safer method uses commercially available media, whereas media presently used must be prepared in the laboratory. Single plaque isolations of the phage BG-1 specifying phage type A and B of M. tuberculosis were readily made by using the modified procedures. This purification and the use of prototype strain Myc 1415 as the indicator host strain have significantly enhanced the ability to discriminate among strains of phage types A and B.
Explore the source record for details and available documents.
Nontoxigenic C. diphtheria, fermenting starch, of convertible phage types ABCDFCH, ABCDFG, ABCDF, ABCD, ABD, ACDf, CDf, AF and A, and also strains of nonconvertible bacteriophage types I, H and K proved to be noncoricynogenic in the corycine test and weakly sensitive to bacteriocin of the No. 3463 test strain (a study was made of a total of 502 strains). Strains (383) isolated from 354 patients and carriers--starch-fermenting and toxigenic to the gravis type--were toxigenic were lysed by a combination of bacteriophages O, P, Q, R, S, T produced an active bacteriocine against the test strains No. 23 BC, and were insensitive to bacteriocine of the strain No. 3453. Strains of phage type G(g) were noncorycinogenic. Only one strain of phage type G, which produced corycine, active against the test strain No. 23 BC served as an exception. With the aid of phages A, B, C, D, F, G, H, I, K it was possible to separate 244 strains of the phage type G(g) into 3 phage types--bc, ABfGH and Abg. Strains of phage type ABfGH were noncorycinogenic; the only strain of phage type bG available produced bacteriocine.
A total of 623 clinical isolates of Staphylococcus aureus were tested for sensitivity to antibiotics by the disk diffusion method and were bacteriophage typed. The emergence of isolates resistant to gentamicin was noted. Eighteen percent of the isolates from patients on surgical services were resistant to gentamicin; 83% of these resistant strains were phage type 95. Five percent of the isolates from patients on services other than surgical were resistant to gentamicin, and 61% of these gentamicin-resistant strains were phage type 94, 96. Physicians are urged to be aware of the possible emergence of such strains with epidemic potential.
Strains of serotypes I and II of Propionibacterium were compared for phage sensitivity. The two serotypes could be distinguished by using a typing set consisting of 16 bacteriophages at concentrations that demonstrated selective lysis of serotype I or II bacterial strains. Seven phage types were found; three were composed exclusively of serotype I, and four were exclusively composed of serotype II organisms. Generally, serotype I strains were more sensitive to phage lysis than were serotype II strains. No correlation was found between phage type and site of isolation.
During 1976-78, 33 S. aureus strains were isolated from chickens suffering from dermatitis and septicemia, omphalitis, pneumonia, arthritis and tenosynovitis; and from a commercial balanced chicken food. All the strains were classified into the biotype B of Hájek and Marsálek. Twenty-nine (87.8%) strains could be classified into Sato et al biological type 4 although they differed from it in its ability to grow at 45 degrees C. The remaining 4 strains differed from the others because they failed in producing hemolysis in bovine and ovine blood agar, egg yolk reaction and splitting of Tween 80. Thirty (90.9%) strains were lysed by avian phages: 28 strains at 1 x RTD and 2 at 100 x RTD. Twenty seven (93.1% strains of the Sato et al biotype 4 were sensitive to the phages CH42/CH43/CH63/CH37 of avian group II, and 2 strains to the phage CHA1 at 100 x RTD. Only one of the 4 unclassified strains could be typed by phage CH4 of avian group I at 1 x RTD. Twenty seven (81,8%) strains were typable at 100 x RTD by the basic set of human phages: 26 strains belonged to group III (53 and 53/77) and 1 to a mixed group I/III (79/53/77). The typable strains belonged only to Sato et al biotype 4. None of 33 strains were sensitive to any of the bovine phages. The biological characters and bacteriophage typing of the S. aureus showed that almost all the strains belong to chicken types. The strains isolated from food belong to the same chicken biotype and phagetype as the strains isolated from dermatitis, septicemia, omphalitis and pneumonia. The strains isolated from arthritis and tenosynovitis were different from the ones isolated from other pathologies.
Explore the source record for details and available documents.
Explore the source record for details and available documents.