PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “BACTERIOPHAGE TYPING”

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.

At least 343 records · Page 19Linked to original sources

[Epidemiologic investigation of infection with Klebsiella using phage typing as a method].

In epidemiological investigations of infections with Klebsiella carried on by us for many years, a lysotyping method was used with a success. The results which are now being presented deal with 638 strains of Klebsiella pneumoniae and Klebsiella oxytoca originating from patients treated in hospitals in Wrocław, Kraków, Gdańsk and Sosnowiec during the years 1986-1992. Susceptibility of strains to the standard set of 14 phages used since ten years decreased significantly, when compared with previously typed strains of Klebsiella. Out of 312 susceptible strains of Klebsiella, majority (302) represented 47 phage types described previously. Sporadic appearance of new phage types was observed. Some phagotypes (37, 47, 112, 117, 119, 142, 153 and 157) were represented most frequently and concerned 55% of susceptible strains. High repeatability of phage types in consecutive groups of typed strains suggests a need for continuation of this method for typing Klebsiella. Decreased susceptibility of strains to standard set of phages requires introduction of new typing bacteriophages.

Bacteriophage Typing↗

[Relation of intrahospital morbidity from staphylococcal infections to some properties of hospital strains].

Analysis of staphylococcus infection morbidity in a large obstetrical hospital for 5 years offered a possibility of establishing an association between the severity of the course of staphylococcus infections in patients, the bacteriophage type of the causative agent and its resistance to antibiotics. The qualitative changes in morbidity in the direction of the prevalence of minor forms and mild course ocurred in parallel with the changes of the leading bacteriophage type from the epidemic 75/77 and 80/81 to the nonepidemic bacteriophage types of the III bacteriophage group and the changes of the antibiograms of the causative agents in the direction of an increase in the number of strains sensitive to antibiotics. Since the severity of the course of staphylococcus infection characterized the pathogenicity of the strain of the causative agent a conclusion could be drawn on the association between the sign of virulence and determinants of the medicinal resistance and definite prophages in the hospital strains of staphylococcus.

Adult↗

Epidemiological typing of coagulase-negative staphylococci from nosocomial infections.

Biotyping, antibiograms, bacteriophage typing, plasmid profile analysis and SDS-PAGE protein profiles were used to determine the relatedness of 44 Staphylococcus epidermidis and four S. haemolyticus isolates from 14 patients. A selection of these were further characterised by ribotyping. Biotyping classified the isolates into three major groups but was considered a poor strain marker. Although antibiograms classified the S. epidermidis isolates into 20 groups, some changes in the susceptibility patterns of related isolates from a single patient were demonstrated. Bacteriophage typing was the least discriminatory of the methods used. SDS-PAGE gave highly related patterns for the majority of S. epidermidis isolates. Plasmid profile analysis and ribotyping, with a minimum of two restriction endonucleases, were the most discriminatory methods for typing S. epidermidis. Nonetheless, some isolates from the same patient - probably representing a single strain - varied in plasmid profile indicating plasmid instability. One of six related isolates from a single patient lacked two bands from the ribotyping pattern of the other isolates. Although no single method proved entirely satisfactory on all occasions, the combination of typing methods was sufficient to provide evidence of the relatedness of S. epidermidis isolates from individual patients.

Adult↗

Nosocomial clonal dissemination of methicillin-resistant Staphylococcus aureus. Elucidation by plasmid analysis.

An outbreak of methicillin sodium-resistant Staphylococcus aureus (MRSA) infection and colonization, mainly centered in the vascular surgery service, occurred in a 1000-bed tertiary care center between December 1983 and December 1984. Methicillin-resistant S aureus isolated before and during the outbreak was studied by both bacteriophage typing and by restriction endonuclease digestion of bacterial plasmid DNA. Bacteriophage typing was discrepant in nine (56%) of the 17 repeated analyses compared with one (3.4%) of the 29 for plasmid profiling. These typing methods revealed that the epidemic strain was introduced to the hospital from the community 15 months before the outbreak. The outbreak was caused by cross-transmission of the epidemic strain by health care personnel and was controlled by treatment of colonized personnel, education of personnel, and institution of barrier precautions for colonized or infected patients. Plasmid profiling with restriction endonuclease digestion was easier, more rapid, and more specific than bacteriophage typing in the evaluation of this outbreak.

Cross Infection↗

Characterization of the Brazilian endemic clone of methicillin-resistant Staphylococcus aureus (MRSA) from hospitals throughout Brazil.

The objective of this study was to characterize patterns of the Brazilian endemic clone of methicillin-resistant Staphylococcus aureus (MRSA) from hospitals throughout Brazil. We studied 83 MRSA strains isolated from patients hospitalized in 27 public and private hospitals in 19 cities located in 14 Brazilian states from September, 1995, to June, 1997. The MRSA strains were typed using antibiograms, bacteriophage typing and pulsed field gel electrophoresis (PFGE). The analysis of genomic DNA by PFGE showed that 65 isolates presented the same PFGE pattern. This pattern was present in all of the hospitals studied indicating the presence of an endemic MRSA clone widely disseminated throughout Brazilian hospitals (BEC). All isolates belonging to the BEC proved to be resistant to ciprofloxacin, erythromycin, lincomycin, trimethoprim-sulphamethoxazole, and tetracycline. Variable susceptibility to these drugs was found only in isolates belonging to clones other than the BEC. The results show that, among MRSA, the BEC is common in Brazil. The best method for mapping changes in the frequency of this clone among MRSA is pulsed field gel electrophoresis. Use of molecular mapping is an important tool for monitoring the spread of potentially dangerous microbes.

Anti-Bacterial Agents↗

[Clostridium novyi type A bacteriophages (author's transl)].

In the culture fluids and on the cells of two toxigenic strains of Clostridium novyi type A, bacteriophages were detected and confirmed by electron microscopy (Fig. 1 and 2). The heads of the bacteriophages are hexagonal and 500 A in diameter. The tails have a length of 1400 A and a diameter of 60 A. Reproduction of the bacteriophages was not yet possible owing to the lack of sensitive indicator strains.

Bacteriophages↗

Transmission of group B streptococci. Traced by use of multiple epidemiologic markers.

During a three-week period, septicemia caused by group B Streptococcus, serotype III, developed in four infants born at a community hospital. The first infant had early-onset disease; late-onset disease that appeared, from epidemiologic data, to be nosocomial developed in the other three infants. Bacteriophage typing and antimicrobial susceptibility testing confirmed the relatedness of the isolates. A prospective study designed to differentiate between vertical and nosocomial transmission of group B Streptococcus showed that of 82 infants, 21 (26%) were culture-positive during their hospitalization, and nine of these infants (43%) had been culture-negative at birth. Although serotype III strains were recovered from four of nine infants with apparently nosocomial acquisition, none of the isolates displayed an antibiogram or bacteriophage type similar to that of the isolates involved in the recent cluster. Bacteriophage typing and antimicrobial susceptibility testing in addition to the use of serotyping may be helpful in epidemiologic studies of group B Streptococcus.

Bacteriological Techniques↗

Isolation of bacteriophages for typing staphylococcus intermedius isolated from pigeons.

Attempts to isolate phages for typing Staphylococcus intermedius isolated from pigeons were made. Five phages were isolated from the lysogenic strains and the nostrils of pigeons, and were used for typing 50 strains isolated from pigeons in Japan, Belgium and Czechoslovakia. Thirty-one (62.0%) of the 50 strains were typed at either routine test dilution (RTD) or 100 X RTD into 8 phage patterns. A total of 122 strains of S. intermedius isolated from dogs, horses, mink and foxes were subjected to phage typing with pigeon phages, with the result that 10 (8.2%) of the 122 strains were typable. S. aureus and S. epidermidis, 59 and 58 strains, respectively, were resistant to lysis due to the pigeon phages. The experimental phages were considerably specific for S. intermedius isolated from pigeons.

Animals↗

PCR-RFLP analysis of the coagulase gene of Staphylococcus aureus: application to the differentiation of epidemic and sporadic methicillin-resistant strains.

Preventing cross-infection with epidemic strains of methicillin-resistant Staphylococcus aureus (MRSA) requires effective control measures. These call for simple, rapid, discriminatory and reproducible methods for typing this pathogen. In this study 140 isolates/strains from 105 hospitals in England and Wales, representing 72 diverse phage types, were analysed by bacteriophage typing and PCR coagulase (coa) gene restriction fragment length polymorphism (RFLP). Isolates gave a coa gene PCR product that was either 660 base pairs (bp), 603 bp or 547 pb in size. The PCR products were digested with Alu I and Cfo I, and the fragments separated by gel electrophoresis. Eight coa gene RFLP patterns, numbered 1 to 8, were observed. Pattern 3 was most common (N = 25 isolates), followed by patterns 2 and 5 (18 isolates each), pattern 1 (14 isolates), pattern 4 (11 isolates), pattern 7 (10 isolates), pattern 8 (eight isolates) and pattern 6 (six isolates). Isolates of the same phage type often gave different coa gene RFLP patterns, and the patterns within the epidemic types EMRSA-03, EMRSA-15 and EMRSA-16 were heterogeneous. Thus, representatives of EMRSA-03 were subtyped to coa RFLP patterns 1 and 2, those of EMRSA-05 to coa RFLP patterns 1, 2, 7 and 8, and those for EMRSA-16 to coa RFLP patterns 2, 3, 4, 5 and 6. The range of patterns within single phage types of S. aureus could help to discriminate between isolates/strains, and in a hierarchical approach coa gene RFLP could occupy an intermediate position between phage typing and pulsed-field gel electrophoresis (PFGE).

Bacteriophage Typing↗

Epidemiologic typing of nosocomial microorganisms.

Hospital epidemiologists often rely upon "typing" of microorganisms to help determine their genetic relatedness. Most general clinical microbiology laboratories can determine biologic profiles (biotypes) and antimicrobial susceptibility patterns (antibiograms) of bacteria commonly isolated from specimens; occasionally serologic typing (serotype) is also performed. Special interest laboratories can provide serologic typing, bacteriophage susceptibility patterns (phage typing), bacteriocin production patterns, bacteriocin susceptibility patterns, plasmid analyses and chromosomal DNA analyses for a variety of bacteria, mycobacteria and fungi of nosocomial interest. Such laboratories can also provide serologic typing, restriction enzyme analyses and other special studies of viruses and related microorganisms. A useful and effective "typing" system should be (1) standardized, (2) reproducible, (3) sensitive, (4) stable, (5) available, (6) inexpensive, (7) applicable to a wide range of microorganisms, and (8) field tested in conjunction with epidemiologic investigation. Results should be reported in a standard manner with some discussion of the implications and limitations of the reported results. We suggest that a registry of typing methods be established to facilitate application of available methods to appropriate epidemiologic investigations.

Bacteria↗

[Evaluation of the usefulness of three collections of bacteriophages for typing methicillin-resistant Staphylococcus aureus, isolated in Moscow hospitals].

The typing of S. aureus methicillin-resistant strains, isolated in different hospitals of Moscow; was carried out with the use of three collections of phages: the International Set of Phages; the set of phages of the International Center of S. aureus phage typing in London (L); and the experimental collection of phages of the Gamaleya Institute of Epidemiology and Microbiology in Moscow (M). In this study made with the use of both the phages of the International Diagnostic Set and phages L in the standard typing dose of 1 TP about 6% of the cultures under study proved to be sensitive. When the typing dose was increased to 100 TP the phages of the international diagnostic set lyzed 75.5% of the cultures. The typed strains were found to belong to phage types 77 (71.7%), 77/84/85 (19.6%) and 94/96 (6.5%). At a concentration of 100 TP phages L lyzed 83.7% of the cultures, but the dominating phage types could not be determined due to a great variety of phage markers. In contrast to the two preceding collections, the third phage collection M was composed in such a way that in the study of the investigated culture the specificity of its restriction modification was primarily evaluated and only then the presence of antiphage immunity was determined. This latter collection was used in the evaluation of 93.1% of the cultures. By the specificity of their restriction specification system the majority of them were classified with two new groups, heretofore not described. Only this collection M made it possible to differentiate epidemic and sporadic strains and to evaluate the epidemic situation in all 6 hospitals.

Bacteriophage Typing↗

Laboratory investigation of a multistate food-borne outbreak of Escherichia coli O157:H7 by using pulsed-field gel electrophoresis and phage typing.

Two hundred thirty-three isolates of Escherichia coli O157:H7 were analyzed by both pulsed-field gel electrophoresis (PFGE) and bacteriophage typing. All 26 isolates from persons whose illness was associated with a recent multistate outbreak of E. coli O157:H7 infections linked to the consumption of undercooked hamburgers and all 27 isolates from incriminated lots of hamburger meat had the same phage type and the same PFGE pattern. Twenty-five of 74 E. coli O157:H7 isolates from Washington State and 10 of 27 isolates from other states obtained during the 6 months before the outbreak had the same phage type as the outbreak strain, but only 1 isolate had the same PFGE pattern. PFGE thus appeared to be a more sensitive method than bacteriophage typing for distinguishing outbreak and non-outbreak-related strains. The PFGE patterns of seven preoutbreak sporadic isolates and five sporadic isolates from the outbreak period differed from that of the outbreak strain by a single band, making it difficult to identify these isolates as outbreak or non-outbreak related. Phage typing and PFGE with additional enzymes were helpful in resolving this problem. While not as sensitive as PFGE, phage typing was helpful in interpreting PFGE data and could have been used as a simple, rapid screen to eliminate the need for performing PFGE on unrelated isolates.

Animals↗

Comparison of epidemiological marker methods for identification of Salmonella typhimurium isolates from an outbreak caused by contaminated chocolate.

Plasmid profile analysis, restriction endonuclease analysis, and multilocus enzyme electrophoresis were used in conjunction with serotyping, bacteriophage typing, and biochemical fingerprinting to trace epidemiologically related isolates of Salmonella typhimurium from an outbreak caused by contaminated chocolate products in Norway and Finland. To evaluate the efficiency of the epidemiological marker methods, isolates from the outbreak were compared with five groups of control isolates not known to be associated with the outbreak. Both plasmid profile analysis and phage typing provided further discrimination over that produced by serotyping and biochemical fingerprinting. Plasmid profile analysis and phage typing were equally reliable in differentiating the outbreak isolates from the epidemiologically unrelated controls and were significantly more effective than multilocus enzyme electrophoresis and restriction enzyme analysis of total DNA. The greatest differentiation was achieved when plasmid profile analysis and phage typing were combined to complement serotyping and biochemical fingerprinting. However, none of the methods employed, including restriction enzyme analysis of plasmid DNA, were able to distinguish the outbreak isolates from five isolates recovered in Norway and Finland over a period of years from dead passerine birds and a calf.

Animals↗

Epidemic typhoid in Chile: analysis by molecular and conventional methods of Salmonella typhi strain diversity in epidemic (1977 and 1981) and nonepidemic (1990) years.

From 1977 to 1986, Chile experienced an important typhoid fever epidemic, despite statistics that indicated apparently improving levels of sanitation of drinking water and sewage disposal. The lack of antibiotic resistance among the Salmonella typhi strains isolated during this period, the mild clinical presentation of the disease, and the initially low level of efficacy of the S. typhi Ty21a vaccine in the population exposed to the epidemic suggested that this epidemic might have resulted from the dissemination of S. typhi strains with unique characteristics. To investigate this hypothesis, we used conventional methods (bacteriophage typing and biotyping) and molecular methods (restriction fragment length polymorphism analysis, ribotyping, IS200 typing, and PCR amplification of the fliC-d gene) to study a population of 149 S. typhi isolates during 1977, 1981, and 1990, the years that included periods with low (when the disease was endemic) and high (when the disease was epidemic) morbidities. Our results indicate that these S. typhi isolates in Chile represent a number of highly diverse variants of the clone of S. typhi with a worldwide distribution described by Selander et al. (R. K. Selander, P. Beltran, N.H. Smith, R. Helmuth, F.A. Rubin, D.J. Kopecko, K. Ferris, B.D. Tall, A. Cravioto, and J.M. Musser, Infect. Immun. 58:2262-2275, 1990). For example, we detected 26 PstI and 10 ClaI ribotypes among 47 and 16 S. typhi strains belonging to this clone, respectively. These results suggest that the Chilean epidemic was probably produced by multiple sources of infection because of deficient sanitary conditions. These findings illustrate the usefulness of molecular methods for characterizing the potential causes of the typhoid epidemics and the possible routes of transmission of S. typhi strains in typhoid epidemics.

Bacterial Typing Techniques↗

Determination of the cos sequence of the mature genome of S2/HP1 type B bacteriophage of Haemophilus influenzae.

The cos region of Haemophilus influenzae phage HP1/S2 type B has been cloned and its nucleotide (nt) sequence determined. The nt sequence of the cohesive ends (cos) and whole cos site of type-B phage have been compared to corresponding sequences of the HP1c1 phage. The results of a search for symmetry elements and IHF-binding sites in this region are presented.

Bacteriophages↗

Genetic and physiological studies of abortive infections of hydroxymethyluracil-containing bacteriophages in lysogens of temperate Bacillus subtilis bacteriophage SPO2.

Wild-type bacteriophage phie and IS (interference-sensitive) mutants of the related phage SP82G did not productively infect strains of Bacillus subtilis that were lysogenic for temperate phage SPO2. In these abortive infections, the sensitive phages adsorbed to and penetrated the nonpermissive host, phage-directed macromolecular syntheses were initiated, but both viral and bacterial nucleic acid production abruptly stopped about 15 min after addition of the phages. The cessation of RNA and DNA synthesis was preceded or coincident with a reduction in oxygen utilization by the infected cultures. Genetic studies of both phie and SP82G suggest sensitivity to SPO2-mediated abortive infection was controlled by a single gene. A mutant of SPO2, SPO2ehp4-, lysogens of which no longer interfere with the development of SP82GIs, was also isolated. The discovery of this ehp- variant suggests the normal SPO2 prophage synthesized a substance that alters cell physiology in some manner detrimental to SP82GIs development. Since SPO2ehp4- grew on and lysogenized bacteria sensitive to wild-type SPO2, the product of the eph gene was apparently not an essential function of this temperate phage.Overall, these observations exhibit remarkable similarities to the inhibition of T4rII mutants by the product of the rex gene of phage lambda.

Adsorption↗