Induction and reversion of the L-form of Neisseria gonorrhoeae

1973 ◽  
Vol 19 (9) ◽  
pp. 1145-1151 ◽  
Author(s):  
John W. Lawson ◽  
James T. Douglas

Massive induction of Neisseria gonorrhoeae to the L-form was achieved on L-media consisting of brain heart infusion broth, 1% agar, 10% horse serum, and 100 units per milliliter penicillin. This medium was supplemented with polyvinylpyrrolidone (PVP) for stabilization. Frequencies greater than 10% were routinely found with all 11 strains tested. Five of the 11 strains were also transformed to the L-form on L-media supplemented with 10% sucrose but at efficiencies much lower than on PVP L-media. Rare L-colonies (less than 1 in 107 gonococci) of these same five strains were also isolated on unstabilized L-media. No L-forms were ever isolated from the remaining six strains on sucrose or on unstabilized L-media. The penicillin concentration in the media, if above a lethal amount, had little effect on the efficiency of L-phase induction on PVP L-media but was critical for isolation on sucrose L-media. Colonial growth of the L-form was much more rapid and luxuriant on PVP than on sucrose L-media. In addition, subculture by the agar-block technique of L-phase colonies induced on PVP L-media routinely occurred while growth was seldom obtained on subculture from sucrose L-media. Reversion to the gonococcal parent occurred (1) on transfer of growth by the agar-block technique to similar media without penicillin or to Mueller Hinton blood agar, (2) in L-broth into which an agar block containing L-colonies was placed and time allowed for decay of penicillin, (3) on sucrose but not PVP L-media, within the original transformed L-colonies after penicillin decay. Growth in PVP L-broth was achieved. On transfer from broth culture to growth media without penicillin, reversion to the parental gonococci occurred.

1919 ◽  
Vol 30 (2) ◽  
pp. 123-146 ◽  
Author(s):  
Mildred C. Clough

In this paper are reported the results of a study of nine strains of pneumococci agglutinating with antipneumococcus sera of all three types (Nos. I, II, and III). Seven of the strains were the cause of serious or fatal infections in human beings. Morphologically they were typical pneumococci with characteristic growth on ordinary media. Most of the strains were soluble in bile, fermented inulin, and caused no precipitation on glucose ascitic fluid agar. Two of the strains, however, resembled streptococci in these three cultural characteristics, but have been regarded as pneumococci on account of their serological reactions. Variations in the cultural reactions occurred with several strains while they were under observation. The virulence of the strains varied greatly, some strains being almost non-pathogenic, and others killing mice in doses of 0.000001 cc. of a 24 hour broth culture. Antipneumococcus Sera I, II, and III agglutinated all the strains in fairly high dilution (1:8 to 1:64 or higher), while normal horse serum caused no agglutination. Antipneumococcus Sera I, II, and III stimulated active phagocytosis of all the strains, while no phagocytosis occurred in control preparations with normal horse serum. These strains elaborated a soluble substance in the body of inoculated mice which caused the formation of a precipitate when the peritoneal washings, cleared by centrifugalization, were added to the antipneumococcus sera of all three types. Antipneumococcus Sera I, II, and III protected mice equally well against 1,000 to 10,000 times the minimal lethal dose of the two strains with which protection tests could be carried out. Absorption of serum of Types I and II with the homologous pneumococcus removed the agglutinins and the bacteriotropins for all these strains. Absorption of these sera with Strains T and N removed the agglutinins and the bacteriotropins for the homologous strain only, and not for typical members of Type I or II, or for the other atypically agglutinable strains reported in this paper. The agglutinins concerned in the agglutination of these peculiar strains are therefore minor agglutinins. As shown not only by agglutination tests, but also by protection tests and agglutinin absorption tests, these organisms bear the same relation to Types I, II, and III, as do atypical Type II strains to Type II. Immune sera were prepared with these strains, and each strain was tested with all the immune sera by means of phagocytic and agglutinative reactions. In general, the strains were found to be serologically distinct, though some interrelationships existed between Strains V and R, and between Strains H, F, and N. These sera had no activity towards strains belonging to Type I or II, or atypical Type II. A mutation occurred in one of the strains, B, while it was under observation. On isolation this strain had the cultural reactions of a typical pneumococcus, and had the phagocytic and agglutinative reactions of an atypical Type II. After 6 months cultivation on blood agar its serological reactions changed, and it became actively phagocyted and agglutinated in antipneumococcus sera of Types I, II, and III. Its cultural characteristics also changed, and it became bile-insoluble, did not ferment inulin, and caused precipitation in glucose ascitic fluid agar. At this time it caused an intense green discoloration at the base of the blood agar slants around the water of condensation. By repeated animal passages this strain was three times made to revert abruptly to its original form (atypical Type IIa), both in cultural and serological reactions. An immune serum was prepared to each form of the strain, and each serum acted strongly on the homologous form, but was without action on the heterologous form of the strain. This mutation suggests that these pneumococci reacting with all three types of antipneumococcus sera may represent primitive, relatively undifferentiated forms from which the fixed types may have arisen.


1978 ◽  
Vol 8 (5) ◽  
pp. 520-524
Author(s):  
A W Brinkley ◽  
T W Huber

A method was devised to test the growth-promoting ability of a broth medium. The "dilute to extinction" method determines the inoculum required to develop heavy turbidity in a broth with overnight incubation. A statistical method using Poisson distribution was used to show that a single Haemophilus cell can develop heavy turbidity in an optimal broth. The dilute to extinction method was used to evaluate the shelf life of stored media, to titrate the growth factor requirements of Haemophilus, and to evaluate the use of purified hemin and nicotinamide adenine dinucleotide in a broth medium for the growth of Haemophilus. Of the media tested, the most suitable formulation was Mueller-Hinton broth supplemented with 10 microgram of hemin and 10 microgram of nicotinamide adenine dinucleotide per ml. The dilute to extinction method appears to be especially useful in the development of broth media for fastidious organisms. The method could also be used to assure the quality of other broth media which are required to support the growth of small inocula in the clinical or research laboratory.


2002 ◽  
Vol 65 (10) ◽  
pp. 1660-1662 ◽  
Author(s):  
JOHN E. MOORE ◽  
ROBERT H. MADDEN

The rapid automated bacterial impedance technique (RABIT) was examined as a method for the detection of two wild-type isolates of Campylobacter coli in broth media. Both isolates failed to produce a change in impedance that was sufficient for detection in any combination of six nonselective basal broth media, including Mueller-Hinton broth, nutrient broth no. 2, brain heart infusion broth supplemented with yeast extract (0.5% [wt/vol]), brucella broth, Campy broth supplemented with yeast extract (0.5% [wt/vol]), and Whitley impedance broth, at 37 and 42°C. Although the strains did proliferate in the media, changes in conductivity were very small (ranging from 0 to 1,000 μS) and were not significantly greater than the drift in conductance observed in the control broth medium. Additional work is therefore required to define a nonionic growth substrate that will produce charged ions upon metabolism that are detectable by RABIT.


1977 ◽  
Vol 6 (3) ◽  
pp. 314-316
Author(s):  
M Gurwith

A rapid screening method for detection of Escherichia coli producing heat-labile enterotoxin is described. Single colonies are transferred directly from primary culture plates into 96-well microculture plates containing 0.3 ml of brain heart infusion broth in each well. After 24 h at 37 degrees C, each brain heart infusion broth culture is assayed by the miniculture method in the corresponding well of a microculture plate in which Y-1 mouse adrenal tumor cells have been grown. All enterotoxigenic isolates detected by this method were confirmed in the assay but with culture supernatants.


1993 ◽  
Vol 56 (1) ◽  
pp. 18-20 ◽  
Author(s):  
JOSEPH L. FERREIRA ◽  
BARBARA R. BAUMSTARK ◽  
MOSTAFA K. HAMDY ◽  
STEVEN G. MCCAY

A DNA fragment of the type A Clostridium botulinum neurotoxin gene was demonstrated in canned food products with the polymerase chain reaction (PCR). The fragment, 1340-bp in size, was amplified from green peas, whole kernel corn, green beans, lima beans, black-eyed peas, and turnip greens previously inoculated with type A C. botulinum. The PCR products were identified by agarose gel electrophoresis and also confirmed by dot blot DNA hybridization with a type A specific gene probe. Some inoculated foods were PCR negative but became PCR positive after subculture and overnight incubation in brain heart infusion broth. No PCR amplification products were obtained from uninoculated foods. The procedure was highly sensitive and detected as few as 100 vegetative cells per ml brain heart infusion broth culture.


1985 ◽  
Vol 31 (11) ◽  
pp. 1041-1050 ◽  
Author(s):  
H. Dick ◽  
R. G. E. Murray ◽  
S. Walmsley

After 3–4 h in a rich fluid medium such as brain–heart infusion broth, motile nonseptate filaments developed from normal short rods and formed about 80% of the cell mass of Proteus mirabilis PM23. This developmental pattern was not observed in any of the other nine representatives of the species. These filaments were considered to be equivalent to swarmer cells formed on agar media because these cells ceased tumbling (i.e., chemotaxis was repressed), they developed large numbers of flagella (i.e., flagella synthesis and insertion was derepressed), and the distribution of nuclei in the filaments indicated that there was normal segregation. The population of cells grown in a minimal medium supplemented with amino acids and nicotinic acid consisted only of short cells with tumbling motility, despite the production of long cells and swarming on the same medium solidified with ordinary agar (refined agar was not effective). These short cells differentiated in 1–1.5 h in brain–heart infusion broth at 37 °C after an initial division. The requirements for initiation of differentiation were good basal nutrition, suitable cations (probably Ca2+ and Na+, or K+), and unknown heat-stable organic factors (molecular weight < 10 000) present in crude agar and yeast extract. Other components of media promoted swarmer differentiation if it was initiated and these included organic acids (lactate), amino acids (proline or serine), phosphate, and an appropriate ionic environment. Comparison of the observed sequence of length classes in brain–heart infusion broth culture with computer generated growth models suggested that, at the outset of growth, 50% of the products of each short cell division ceased septation but grew in length for about five doubling periods and then divided cells from each end at a faster rate (3–5 times per hour) for return to the short cell pool.


1965 ◽  
Vol 11 (5) ◽  
pp. 823-827 ◽  
Author(s):  
R. Pakula ◽  
A. H. W. Hauschild

The competence-provoking factor produced by the highly transformable group H streptococcus, strain Challis, was used to provoke efficient transformability in the poorly transformable group H streptococcus, strain Wicky. Transformations to streptomycin resistance were carried out with C14-labelled DNA which was extracted from bacteria fed with thymidine-2-C14.When cultures of strain Wicky were grown in Difco brain–heart infusion broth, supplemented with serum, and treated with competence factor and deoxyribonucleic acid, 25 to 40% of viable units were transformed while no transformation occurred without the factor. At the same time, the incorporation of C14 into cells treated with competence factor was higher than incorporation of C14 into untreated cells.Crude preparations of the competence factor had a retarding effect on growth of the streptococcus, irrespective of whether DNA was added.


1990 ◽  
Vol 53 (9) ◽  
pp. 790-792 ◽  
Author(s):  
M. W. GRIFFITHS

Using a reversed passive latex agglutination assay, about 85% of psychrotrophic Bacillus spp. tested were shown to produce diarrhoegenic toxin during growth on brain heart infusion broth at 25°C. The majority of these strains were identified as Bacillus cereus or cereus-related strains. However, a number of other species was capable of synthesizing the toxin. Further investigation of four psychrotrophic Bacilli showed that the toxin was produced during growth in milk at temperatures ranging from 6 to 21°C. Toxin production increased with increasing temperatures and was not synthesized in appreciable quantities until the bacterial count exceeded 1 × 107 cfu/ml.


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