It is used to trace the source of outbreaks of infections. Phage typing still remains as the gold standard method for epidemiological surveillance of s. Technical details are given ofmethods recommendedfor determining the phage type ofstaphylococci and the interpretation of differences between the types is. Salmonella typhimurium phage typing for pathogens springerlink. This phage type represents the most commonly isolated e. Pdf phage typing, pcr amplification for meca gene, and. Phagetypes of120clinicalstrains of klebsiella strains phagetype no. Pdf biotyping, serotyping and phage typing of streptococcus. Nov 23, 2016 a phage coded protein, called a repressor, is made which binds to a particular site on the phage dna, called the operator, and shuts off transcription of most phage genes except the repressor gene. Bacteriophages, known as phages, are a form of viruses.
Bacterial typing methods suitable for epidemiological. Phage typing is carried out in a few specialized laboratories, and thus is not commonly used. Ppt phagetypingmicrobiology powerpoint presentations and. A phage typing technique for salmonellae is described. Media and methods for phagetyping mycobacteria who world.
The identification, typing and fingerprinting of salmonella. Threlfall, in international encyclopedia of public health, 2008 salmonella typhi. A third strategy is the dual phage technology, which enhances the specificity of phage typing even further. Immunityconferring lysogenic phages have been isolated fromall phage typesofv. A total of 25 phage type macrorestriction pattern combinations were identi.
The viruses that infect bacteria are called bacteriophages phages for short and some of these can only infect a single strain of bacteria. Thebiotypes andcapsular serotypes ofthe 120 strains were also determined. The result is a stable repressed phage genome which is integrated into the host chromosome. A new phagetyping scheme for salmonella typhimurium. The infectious particle that gives rise to a plaque is called a pfu plaque forming unit. This phage type was routinely propagated by infection of a serovar typhi ty2 derivative, brd948, which is highly attenuated and thus allowed its use in a cl2 environment 16. Plasmid pattern analysis of staphylococcus species isolated from. This set wasthen usedto type 937 listeria isolates which 100 90 80 70 60 50 40 30 20 10 0 typability % had been collected during routine investigation of various foods, dairy products, and silage as well as during sampling ofa. Phage typing is a rapid, economical, reliable, and reproducible technique, requiring no specialized equipment, for fingerprinting diseasecausing agents for epidemiological investigation and surveillance. Overall, comparable diversity indices were calculated for pfge and mlva both di0. Characterization of salmonella typhimurium isolates from. View and download powerpoint presentations on phage typing microbiology ppt.
The final phage set derived is detailed in table 1. Bacteriophage typing an overview sciencedirect topics. In only a few cases was one particular serotype clearly related to a particular phage type, and in several cases single types recognized by one method contained several different types when tested by the second method. For one group of strains, the results showed that phage typing could subdivide unrelated strains with the same xba i pfge pattern into phage types 1, 8, 14, and 32, and the use of an additional restriction enzyme for pfge indicated that there were genomic. Molecular characterization of the salmonella enterica serovar. However, mlva was phage type dependent providing better discrimination of the most common phage types. In turn, isolates of vi phage type e1 of pfps x3x5 are closely related to pfp x2 and could have been. Plaque assayassay for lytic phage lytic phages are enumerated by a plaque assay a plaque is a clear area which results from the lysis of bacteria. Typhimurium strains were phage typed correctly by all laboratories. Phage typing provides a rapid, accurate, and cheap method of investigating salmonella strains for epidemiological use. Eight hundred sixtysix isolates from cases of bovine mastitis were used in this effort. Propagation of the typing phages is most often performed by the addition of a suspension of the stock phage to its specific propagating strain of the surface of agar plates 3 4 or within a semisolid agar overlayer 3. Improved procedure for bacteriophage typing oflisteria. Phage type a was the most prevalent type identified and comprised 73.
By mixing a known virus type with a number of different types of bacteria and growing these in separate lawn cultures, it is possible to identify the bacteria serving as the host strain. In the southeast and northeast regions only phage type a was observed regardless the year when the strains were isolated. In general, the methods used in typing one group of bacteria may be applied to other groups, provided the necessary adaptations are made. Bacteriophage typing, clindamycin, methicillin resistant staphylococcus aureus. Only the correct host culture will develop plaques.
The vi phage e1 stock designated g2362 was obtained from the bruce stocker laboratory stanford university. Serovar typhi vi phage type ii was used in the present study. Pfge subtyping differentiated between unrelated strains that exhibited the same phage type, and in. Enterotoxins and phage typing of staphylococcus aureus isolated from clinical material and foods in libya. A traditional biotechnological application of phages is their use to determine the. The developments in next generation sequencing ngs have now made it possible to readily sequence. Types recognizable with the older scheme of felix and callow remain distinct with the new system.
Fiftyseven lysis patterns or phage types have been identified torre et al. This drugsensitive progenitor strain is genotypically distinct from the type strain of vi phage type e1, isolated in russia in 1918 and more recently in the dominican republic. View of phage typing strains of staphylococcus aureus resistant to. Failure of bacteriophage typing to detect an interhospital outbreak. Phage typing sequence typing typing of food or waterborne viruses norovirus and hepatitis a virus typing of food or waterborne parasites giardia and cryptosporidium the document is intended to be of help to nonmicrobiologists working with fwd outbreak investigations. Pure cultures of bacteria are flooded onto plates, and suspensions of typing phages are spotted onto the plates. Phage typing is a method sometimes used along with serological typing in the identification of unknown. A comparison has been made between the bacteriophage and serological methods for identifying types among coagulasepositive staphylococci. Biotyping, serotyping and phage typing of streptococcus faecalis isolated from dental plaque in the human mouth march 1987 journal of medical microbiology 231.
The phage typing results for eueea laboratories showed that 8 8% of the s. However, the latter method offers a finer subdivision of the organism than does the former. Bacteriophage therapy, the use of bacteriophages to treat infection, was used. Hence, they were of no particular use in phage typing. Epidemiologic subtyping of escherichia coli serogroup o157. Phage therapy, viral phage therapy, or phagotherapy is the therapeutic use of bacteriophages to treat pathogenic bacterial infections. Bacteriophage considered as a major risk factor acquires s. Study of corynebacterium diphtheriae strains isolated in. Molecular fingerprinting of multidrugresistant salmonella.
Preoptimized phage therapy on secondary acinetobacter. Salmonella strains within a particular serovar may be differentiated into a number of phage types by their pattern of susceptibility to lysis by a set of phages with different specificity. The first phage typing scheme was based on the principle of phage adaptation and was developed for the differentiation of typhi. Dna profiles were visualized by uv light after ethidium bromide staining, and photographed with a red filter and polaroid 667 film. Typhi isolates were e1 phage type followed by uvs4, a and uvs1.
Phage type, vi phage type, vi type, type are expressions used to describe the types of organism distinguishable by phages. Many difficulties beset the use of undiluted lysates. Phage typing, a procedure for characterizing and detecting bacterial strain by their reaction whether they are susceptible or resistance to various known str. Furthermore, 5loci mlva was a less laborious method and easier to interpret than xbaipfge. Romania, russia and moldova by phage typing, ribo typing. Serial dilutions of phage preparations is applied on a lawn culture of a susceptible bacterial strain. One example of a reporter phage system is using luciferase to detect mycobacteria. Phage typing has largely been replaced by molecular typing. Find powerpoint presentations and slides using the power of, find free presentations research about phage typing microbiology ppt.
In general, the methods used in typing one group of bacteria may be. For example, phage have been identified that exhibit specificity for vi capsule producing salmonella enterica serovar typhi. Geographic distribution of phage types of bioserotype 4,o. Phage types pts 8 and 26 are the most predominant phage types in the uk consisting of 50% of isolates torre et al. Whereas fisk 38 had applied his phage as undiluted lysate, they adopted the useofthe routinetest dilution, i. Comparisonofbacteriophage typing, serotyping, and biotyping. Strains that are susceptible to infection by the same phages are allo1993. Please note that typing methods develop rapidly and that. Abdulmula elghodban1, khalifa sifaw ghenghesh2, and karoly marialigeti1 abdurrahman tawil3 1 dept. Pdf enterotoxins and phage typing of staphylococcus aureus. Xbaipfge than for phenotyping methods phage typing. Phage typing definition of phage typing by medical dictionary.
One battery of phages was used to type three serotypes of salmonella, namely, s. Here we have characterized the viassociated e1 typing bacteriophage using a number of molecular approaches. A phage typing set composed of 32 phages is described for differentiating escherichia coli. Phage typing phage typing is the characterization of bacteria based on susceptibility to infection by a defined panel of bacteriophages. Typing of pantonvalentine leukocidinencoding phages carried.
One hundred and ten types were sensitive to one phage preparation, and 42 types were sensitive to two or three phages. The changing trends in antimicrobial resistance pattern over the years necessitate. Conventional and molecular typing of salmonellatyphi strains. Virchow was developed in 1987 and comprises typing phages chamber et al. Use of molecular subtyping to document longterm persistence. Some bacteriophages target potentially pathogenic bacteria by exploiting surfaceassociated virulence factors as receptors. Thirtysix phage types were only found among the phage type reference. The current international phage typing scheme for s. The infected cell will produce luciferase and by adding luciferin, a light signal will be produced that can be measured. New options for rapid typing of salmonella enterica serovars.
Pdf reduced set of phages for typing escherichia coli. Staphylococcus aureus is one of the major causes of community and hospitalacquired infections. For testing bacteriolysis phage preparations are standardised by titration. Dna sequencing of the sau119 phage and design of a new typing scheme phage dna was extracted from 100 ll of the phage. Phage typing is the most widely recognized typing method for staphylococcus aureus and is also still used widely for subdividing serotypes of pseudomonas aeruginosa and salmonella shigella spp. A hostrange mutant of a phage possesses the power to attack strains that are resistant to the parent phage. Antibodies can be distributed to different labs to allow comparisons rapid same day by many methods and cheap once set up full typing usually incurs delay getting to reference laboratory still used for salmonella speciation, also legionella. Phage typing is a method used for detecting single strains of bacteria. Phage typing is most useful in intraspecies typing of bacteria e. The document is intended to be of help to nonmicrobiologists working with fwd outbreak investigations.
A bacterial phage type is lysed by its homologous typing phage, but may be resistant to a heterologous phage. A comparative study and phage typing of silagemaking. Brief description of frequently used typing methods. Results of phage, k, o and pfge typing phage typing of the 489 isolates identi. Exercise 23a introduction to viruses and phage typing. Routine phage typing methods for salmonella, shigella and other genera.
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