Salmonella typhimurium Mutations Conferring Resistance to Felix O Phage without Loss of Smooth Character: Phage Attachment and Immuno-chemical and Structural Analyses of Lipopolysaccharides

Lindberg, Alf A.; Svensson, And S.

doi:10.1099/00221287-87-1-11

Cited by 10 publications

(8 citation statements)

References 9 publications

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“…This could not easily be tested, because the rate of adsorFtion of FO phage even to smooth FO-sensitive S. typhimurium strains is too low to be easily measurable. However, the results of Lindberg & Svensson (1975) are compatible with the hypothesis that FOR mutants owe their resistance to failure to adsorb. The LPS extracted Y…”

Section: Discussionsupporting

confidence: 80%

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Mutations in Salmonella typhimurium Conferring Resistance to Felix O Phage without Loss of Smooth Character

MacPhee

Krishnapillai

Roantree

et al. 1975

Journal of General Microbiology

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S U M M A R YSeveral mutants obtained from smooth SalmoneIla typhimurium strains by selection for resistance to Felix 0 (FO) phage [whose receptor site includes the N-acetylglucosamine branch of the lipopolysaccharide (LPS) core] were smooth in cultural properties, antigenic character and phage sensitivity pattern (except for their FO resistance). However, the affected genes of several such 'FOR' (FOresistant) mutants were shown by transduction to map in the short cysE-pyrE segment, which includes nearly all known rfa genes responsible for synthesis of LPS core. All of seven FOR mutants differed from their parents, and resembled rfa mutants with defects in the deeper part of the LPS core, by increased sensitivity to various antibiotics. One FOR mutant was non-virulent (LD,, > 107, compared with < IOO for its parent); L T~ derivatives given this FOR gene by co-transduction with cysE+ were likewise non-virulent. It is inferred that FOR mutations affect the assembly of the inner part of the LPS core, perhaps causing incomplete blocks in glycosyl transferase reactions. I N T R O D U C T I O NFelix 0 phage (hereinafter called FO) attacks nearly all smooth strains of Salmonella, whatever their 0 antigen, but is active on very few strains of Escherichia coli, etc. (Kallings, 1967). In Salmonella typhimurium it attacks not only smooth strains but also some nonsmooth mutants: those unable to transfer 0 chains from their site of synthesis to the 'complete' lipopolysaccharide (LPS) core, through mutation at rfaL or rfbT; the semirough (SR) class rfc, deficient in polymerization of 0 repeating units; and classes rfb and ymi, unable to synthesize 0 repeating units (Wilkinson, Gemski & Stocker, 1972). Phage FO, however, does not attack rfa mutants of various classes in which synthesis of the LPS core is defective. Lindberg and his colleagues (for review see Lindberg, 1973), from host range and from measurements of rates of adsorption by whole bacteria and of neutralization by isolated LPS, infer that the N-acetylglucosamine side-branch which is attached to the glucose I1 unit of the complete LPS core (Fig. I ) is an essential part of the adsorption site of FO phage. Most mutants selected from smooth strains by application of FO phage are of type [fa, with various sorts of defects in LPS core structure, and are recognizable as such by sensitivity to different combinations of rough-specific phages and/or to bile salts and by total or partial loss of 'smooth' cultural characters, 0 antigen(s) and sensitivity to smoothspecific phages (Wilkinson et a/. 1972). We here describe FO-resistant mutants of smooth * Present address :

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Section: Discussionsupporting

confidence: 80%

“…The prototrophic transductants arising were purified by single-colony re-isolation on selective medium before testing for phage sensitivity, etc. Lindberg & Svensson (1975) * FOR: smooth in phage sensitivity pattern but resistant to FO phage (see text). rfaF: class of mutant deficient in addition of heptose II unit of LPS core.…”

Section: E T H O D Smentioning

confidence: 99%

Mutations in Salmonella typhimurium Conferring Resistance to Felix O Phage without Loss of Smooth Character

MacPhee

Krishnapillai

Roantree

et al. 1975

Journal of General Microbiology

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“…non-fimbriate, inositol-negative and rhamnose-negative (Morgenroth & Duguid, 1968 from two smooth FOR strains (Lindberg & Svensson, 1975) most of these LPS showed serological relatedness to one or more types of core-defective LPS due to rfa mutation. We also investigated the map position of genes causing the FOR mutation; nine of ten mutations tested were located in the main cluster of rfa genes, between cysE and pyrE; the tenth mutation, causing the FOR phenotype of a newly isolated mutant, was located elsewhere.…”

Section: 'Rb1mentioning

confidence: 97%

“…ml-l to nutrient agar plates inoculated by flooding or streaking from broth cultures. Rates of irreversible adsorption of phage FO were measured by the chloroform method (Lindberg & Svensson, 1975); the adsorbing suspension contained exponential-phase broth-grown bacteria, at about 2 x los ml-l, in 0-05 M-Tris/HCl buffer, pH 7-2, with 0.15 M-NaCl.…”

Section: Mediamentioning

confidence: 99%

“…FOR mutants were thought to have defects, of unknown nature, in their core structure reducing the number, and/or the accessibility to FO phage, of completed core oligosaccharide chains. Lindberg & Svensson (1975) examined two of these FOR mutants in respect of ability to adsorb various phages and of LPS structure. Both FOR mutants contained as much LPS, with as high a proportion of 0-specific sugars in it, as did their wild-type FO-sensitive parent strain; moreover, the average number of repeat units per 0 chain was the same, about 30, in the FOR mutants and the FO-sensitive parent.…”

Section: Introductionmentioning

confidence: 99%

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Lipopolysaccharide Core Defects in Salmonella typhimurium Mutants Which Are Resistant to Felix O Phage but Retain Smooth Character

Hudson¹,

Lindberg²,

Stocker³

1978

Journal of General Microbiology

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FOR mutants of Salmonella typhimurizrm are resistant to Felix 0 phage, whose receptor includes the N-acetylglucosamine branch of the lipopolysaccharide (LPS) core, but smooth in cultural properties, antigenic character and phage sensitivity pattern (MacPhee et al., 1975). The rfa(F0R) genes determining the FOR character of nine mutants were transduced into a smooth cysEpyrE recipient: the nine FOR transductants (and a tenth FOR mutant) were then made rfb (i.e. unable to make 0 chains) by transduction or Hfr crosses. The rfb FOR strains were sensitive to FO phage but nearly all of them showed a somewhat reduced efficiency of plating and diminished rate of adsorption of the phage. This observation and the Ra (complete core) serological activity of their LPS (tested by haemagglutination inhibition) indicate the presence of some, but less than the normal number of, completed core chains in FOR rfb LPS. On the basis of the sensitivities of the FOR transductants and their rfb derivatives to various ' rough-specific' phages, their increased sensitivities to some antibiotics and to deoxycholate and the serological activity of the rfb FOR LPS in various incomplete core systems, the mutants were divided into three groups: (i) five mutants with probable defects in previously undetected rfa gene(s) concerned with formation of both the galactose I and the galactose 11 units of the LPS core; (ii) two mutants with defects inferred to affect the structure of the inner part of the core and also interfere with addition of the N-acetylglucosamine branch; (iii) three mutants in which no type of incomplete core could be detected, probably affected in formation of the inner part of the core chain. The mutation of one mutant of the last class, unlike those of the other nine mutants tested, lay outside the cysE-pyrE segment, in the 90 to 116 min region of the linkage map. I N T R O D U C T I O NFelix 0 phage (FO phage) attacks nearly all Salmonella with a complete lipopolysaccharide (LPS) core; it acts both on smooth strains, whose LPS core bears 0 chains, and on rough strains which make complete core LPS without 0 chains, i.e. classes rfb and rfaL. F O phage does not attack rough mutants of other rfa classes, which make incomplete LPS core (Wilkinson et al., 1972), nor does it act on galE or galU mutants, which make incomplete core because of their inability to synthesize UDPgalactose or UDPglucose. From its host-range and other evidence it was inferred (for review, see Lindberg, 1973) that the N-acetylglucosamine side branch attached to the distal, glucose 11, unit of the oligosaccharide chain of complete LPS core (Fig. I ) is an essential part of the site of adsorption of FO phage. MacPhee et al. (1975) described a class of Salmonefla fyphimurium mutants, called FOR, which are resistant to FO phage but smooth in cultural and serological

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Salmonella typhimurium mutants defective in UDP-D-galactose:lipopolysaccharide alpha 1,6-D-galactosyltransferase. Structural, immunochemical, and enzymologic studies of rfaB mutants.

Wollin¹,

Creeger²,

Rothfield³

et al. 1983

Journal of Biological Chemistry

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Salmonella typhimurium Mutations Conferring Resistance to Felix O Phage without Loss of Smooth Character: Phage Attachment and Immuno-chemical and Structural Analyses of Lipopolysaccharides

Cited by 10 publications

References 9 publications

Mutations in Salmonella typhimurium Conferring Resistance to Felix O Phage without Loss of Smooth Character

Mutations in Salmonella typhimurium Conferring Resistance to Felix O Phage without Loss of Smooth Character

Lipopolysaccharide Core Defects in Salmonella typhimurium Mutants Which Are Resistant to Felix O Phage but Retain Smooth Character

Salmonella typhimurium mutants defective in UDP-D-galactose:lipopolysaccharide alpha 1,6-D-galactosyltransferase. Structural, immunochemical, and enzymologic studies of rfaB mutants.

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