Isolation and Reversion of L Forms of Betahemolytic Streptococci

Crawford, York E.; Frank, Paul F.; Sullivan, Betty

doi:10.1093/infdis/102.1.44

Cited by 21 publications

(8 citation statements)

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“…Isolation of Streptococcal L Forms.--L forms were isolated by a modification of the penicillin gradient technique described originally by Sharp (19)(20)(21). In this method bacteria are streaked over the surface of a modified nutrient agar plate containing penicillin in a ditch at one end.…”

Section: Streptococcal L Formsmentioning

confidence: 99%

Studies of L Forms and Protoplasts of Group a Streptococci

Freimer

Krause

McCarty

1959

The Journal of Experimental Medicine

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The term ' % form" has been applied to certain morphological variants of bacteria which grow in special media as minute colonies composed of pleomorphic globules that do not take the Gram stain (1, 2). These bacterial variants show a high degree of mechanical and osmotic fragility, and their properties suggest that they may lack a rigid bacterial cell wall.The first direct evidence for the absence of a cell wall was obtained by Sharp a al.(3) who demonstrated by chemical and serological techniques that L forms of Group A streptococci lack the group-specific carbohydrate, a major component of the streptococcal cell wail. Chemical analysis of L forms of other species also indicates that important constituents of the cell wail are not present (4).Enzymatic removal of the ceil wall from living bacteria without disruption of the cell was described by Weibuil (5). His initial studies involved the action of lysozyme on B. megatherium in a hypertonic environment provided by sucrose, and the spherical structures remaining after removal of the ceil wail were termed protoplasts. Protoplasts have now been prepared by similar techniques from many bacterial species, and they share the property of requiring a hypertonic environment which can be supplied either by sucrose or salts (6). Dilution of a suspension of protoplasts with water results in their disruption (5). The protoplast membrane, which remains as a well defined structure after osmotic rupture, has been shown by morphological and chemical studies to be distinct from the bacterial ceil wall (7-9). The viability of protoplasts is indicated by their metabolic activity and by the observation of "budding" and "dumbbell" forms (10, 11). However, reproduction of protoplasts in a nutrient medium has not been described.Group A streptococci offer certain advantages for a study of the relationship of L forms and protoplasts to each other and to the parent bacterial forms,

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Section: Streptococcal L Formsmentioning

confidence: 99%

Studies of L Forms and Protoplasts of Group a Streptococci

Freimer

Krause

McCarty

1959

The Journal of Experimental Medicine

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“…Quantities of L colonies were determined irrespective of the size of each colony. To ascertain whether each colony is derived from S. typhimurium or S. schottmiiUeri, a small piece of agar containing an entire L colony was removed with a loop and was implanted into a medium that was lower in salt concentration in the absence of penicillin and serum following the method of Crawford et al [7]. The medium consisted of BHI broth supplemented with 1% agar, 0.4 M NaCl and 1% yeast extract.…”

Section: Reco~ery Of L Forms From the Livermentioning

confidence: 99%

Mechanism of the protective immunity against murine typhoid: persistence of salmonella L forms in the liver after immunization with live-cell vaccines

Kita

Nishikawa

Kamikaidou

et al. 1992

FEMS Microbiology Letters

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Live‐cell vaccines of Salmonella typhimurium, either a sub‐lethal dose of a wild‐type (strain LT2) or a high dose of its two‐heptose Rd1 mutant (strain SL1004), induced acquired resistance to murine typhoid, which remained 180 days after immunozation. Growth of S. typhimurium as a bacillary form ceased between days 30 and 60 of immunization, but L forms of this bacterium colonized the liver (the mean number of L forms in the liver: 600 L‐forming units) even at 180 days post‐immunization. In contrast, a high inoculum of either a Ra mutant (strain TV148) of strain LT2 or S. schottmülleri 8006 sharing the same O antigenic components with those of S. typhimurium induced only a short‐lived protection in proportion to the number of L forms in the liver, and the protective immunity was lost before day 180. However, there was no significant difference in the salmonella‐specific T‐cell responses among groups of immunized mice on day 180 of immunization. A lethal infection with strain LT2 in mice which had been immunized 75 days previously with living cells of strain SL1004 resulted in a rapid clearance of the challenge inoculum, together with a rapid elevation of anti‐S. typhimurium antibody responses. Thus, the present data suggest that the long‐lived immunity conferred upon live S. typhimurium vaccines is attributable to the colonization of this bacterium in the liver as L forms and the ability to colonize the liver as L forms is independent of the brain length of salmonella O‐antigens.

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“…Induction -Several antibiotics and/or osmotic stabilisation (CRAWFORD et al, 1958;FREIMER et al, 1959;ROBERTS, 1967;STROMINGER et al, 1967;DALTON et al, 1971;BRORSON et al, 1973;PACHAS and CURRID, 1974).…”

Section: Introductionmentioning

confidence: 99%

On the Importance of Bacterial L‐Forms in Pigeons*

Kiessling

Gerlach

Kösters

1990

Journal of Veterinary Medicine, Series B

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Summary Following a definition of bacterial L‐forms and a literature review on introduction and reversion of bacteria to and from L‐forms, respectively, the results of a study comprising 587 samples (316 pigeons and 271 pigeon eggs) are reported. As a control 25 free living pigeons and 25 eggs of those pigeons were used, because antibiotic treatment of these could be excluded. From 79 samples (75 pigeons and 4 eggs) Salmonella typhimurium var. copenhagen (STMC) was isolated (non from the urban pigeons), of them 11 in the L‐form from joints and organs and 3 from eggs. 325 of other bacterial isolates were found as L‐forms (=approx. 40%). Out of 168 serum samples investigated, 33.9% showed antibodies against STMC. Corresponding antibodies could only be demonstrated in 73.4 % of the pigeons with a STMC isolate. The occurrence of L‐forms explains resistance to therapy and the failure of vaccines. The high frequency of L‐forms is probably an indication of an inconsequential use of antibiotics in managing pigeon diseases.

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Isolation and Reversion of L Forms of Betahemolytic Streptococci

Cited by 21 publications

References 0 publications

Studies of L Forms and Protoplasts of Group a Streptococci

Studies of L Forms and Protoplasts of Group a Streptococci

Mechanism of the protective immunity against murine typhoid: persistence of salmonella L forms in the liver after immunization with live-cell vaccines

On the Importance of Bacterial L‐Forms in Pigeons*

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