Berg Jw

Bio: Berg Jw is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 11 citations.

The dual nature of acid-fastness.

Abstract: Acid-fastness is usually defined by the Ziehl-Neelsen technique: staining in carbol-fuchsin, differentiation in HCl-alcohol, and counterstaining in methylene blue.8 As a result, acid-fast substances are red, non-acid-fast materials, blue. Some authors have felt that this property of differential staining resided in one specific type of compound, the mycolic acid type of long-chain fatty acid found only in the acid-fast mycobacteria.\" Most authorities, however, now consider that the bulk of the evidence supports a structural rather than a chemical explanation of the phenomenon. It is certainly true that grindinge6 or crushing' tubercle bacilli abolishes their acid-fastness although no change in chemical composition may be detected. Similar, but not identical, acid-fastness has been produced in a number of usually non-acid-fast bacteria by coating them with lipid not in itself acid-fast.' Spores of bacteria are usually acid-fast9 so long as their protective capsule is present. Finally, mycolic acid, the presumed acid-fast compound in tubercle bacilli, was reexamined'9'2' and found to be somewhat acid-fast, but not strongly enough to account for the brilliant staining of intact bacilli. It has been recently noted2 that under certain conditions spermatozoa are acid-fast. When an explanation of this observation was sought, certain contradictions in the basic theory became manifest. The original report of acid-fastness was by Neisser.\" He reported that lepra bacilli, once stained, were resistant to acid destaining. This was in contrast to the ease with which other known bacteria were destained. A year later Ehrlich\" noted a similar property in tubercle bacilli. In these latter organisms, this resistance to destaining was coupled with a resistance to staining and to chemical treatment generally.'0\"15 Out of this generalized resistance of tubercle bacilli has grown the structural theory of acid-fastness.' However, neither lepra bacilli\" nor spermatozoa showed any staining resistance comparable to tubercle bacilli. It therefore appeared questionable whether the structural theory of acid-fastness as presently developed was completely valid. The object of this present paper then is to study both the differences and simi-

Phenolic acridine orange fluorescent stain for mycobacteria.

Abstract: A new fluorescence acid-fast staining method with acridine orange as the specific stain is presented. Only two reagents are required: the acridine orange-specific stain and a destaining-counterstaining reagent. Compared with auramine fluorescence acid-fast staining, there was less nonspecific staining of non-acid-fast debris which fluoresced a pale green contrasting color to provide a background in which to search for the red-to-orange fluorescing acid-fast bacilli. The results of the study indicate that the acridine orange method is superior to the auramine method in detecting acid-fast bacilli in specimen smears.

Cell wall-deficient forms of mycobacteria*

Abstract: Observation of pleomorphic, atypical forms of the tubercle bacillus has a long history, studded with famous names. A sizable tome would result from compiling the data on the granules of Much20 and of Guru ,* the filterable particles of Calmette and Valtis? the dimorphic phase of Csillag? Alexander-Jackson’s zoological stages,’ Rosenthal’s motile and the variety of aberrant forms studied by Kahn,g to mention only a fraction of the literature on in vitro and in vivo studies. There are, however, factors that make culture of the variants difficult. Many components of culture medium may inhibit variant growth. Some commonly used dyes precipitate in masses that are indistinguishable from colonies of the variants. Although filterable particles are omnipresent in the cell walldeficient (CWD) cycle, demonstration of these is difficult because their number is often small. However, one can make a classroom exercise of filtering a streptomycin-treated culture of Mycobacterium tuberculosis through Saran Wrap@ cellophane, as reported for Proteus variants.15 A pure culture of the variants develops in the medium beneath the membrane. Such filtration will not occur, however, if the thicker cellophane now generally marketed is employed, nor will filtration to any extent occur through cellulose acetate membranes. The current paper makes one contribution of clinical interest to the subject of variation in the mycobacteria. Surprisingly, variants of pathogenic mycobacterial species can appear in blood cultures after only 48 hours’ incubation. The remaining problem is specifically to identify these microorganisms in time to relate to therapy. Several methods for recognizing these forms are currently under investigation in our laboratory. Contributions from other investigators may also provide solutions.

Acid-fastness as a histochemical test.

Abstract: Recent work from this laboratory (Berg, 1) has shown that the acid-fastness seen in mycobacteria can reside in two different properties of the cells. First, there was an acid-fastness dependent upon cell structure and shown by intact but not by crushed tubercie bacilli. Secondly, in the same cells there was an acid-fastness not altered by structural changes but rather dependent upon chemical properties. It was lost when and only when mycolic acid was removed from the cells. Further, purified mycolic acid showed the same type of acid-fastness and to the same degree. Lepra bacilli and sperm showed only the second type of acid-fastness and again it was also found in the mycolic-acid-like lipids extracted from these cells (Berg, 1, 2). Further work (Berg, 3) described the unique reaction that took place between these lipids and one dye which was capable of giving the acid-fast reaction, crystal violet. Among other properties, the dye-mycolic acid complex exhibited intense absorption of light at 3500 A while such absorption was not shown by the dye alone, the acid alone, or any other type of acid tested in combination with the dye. In this paper, it is shown that the same dye complex was formed in acid-fast cells as in the test-tube when the absorption spectra were determined for materials in tissue stained with crystal violet. In addition, a number of other reactions of the acid-fast material in the cells are described. The separation of the acid-fastness of mycobacteria from that shown by keratohyaline granules, Russell bodies and ceroid gives at least this first type of acid-fastness the character of a histochemical test.

The nature of mycobacterial acid-fastness.

Abstract: Phenol is not essential to acid-fast staining, for it will occur in the absence of phenol where such lipoid-soluble basic dyes as night blue, Victoria blue B or Victoria R are used; it is essential for acid-fast staining with water soluble basic dyes such as basic fuchsin. When phenol is added to the staining solution, such water soluble basic dyes behave in effect like their lipid-soluble counterparts. The loss of mycobacterial acid-fastness with carbolfuchsin after bromination or chromation indicates that this phenomenon is related to the presence of unsaturated lipids in the bacterial cells. Within the cells these acid-fast lipids are bound in such a way that they are easily removed from all mycobacteria by hot dilute HCl; from leprosy bacilli alone they are easily removed with hot pyridine. From the results of various blocking reactions it appears that carboxyl and especially hydroxyl groups of these cellular lipids are essential to the acid-fast reaction of mycobacteria.

[Quantitative histochemical studies on acid-fast staining of the sperm head].

Abstract: Die bei der sog. saurefesten Farbung im Spermienkopf enthaltene Kristallviolettmenge kann quantitativ mit cytophotometrischen Methoden bestimmt werden. Eine Fixierung mit abs. Alkohol und Farbung bei pH 7,5 ergab eine fur quantitative Zwecke optimale Anfarbung. Die gebundene Kristallviolettmenge ist der DNS-Menge des Spermiums proportional. Es wird vermutet, das die saurefeste Farbung auf einer Bindung des Kristallvioletts an die Phosphatgruppen der Nukleinsauren beruht und das die spezielle Anordnung der Nukleoproteine im Spermium eine wesentliche Rolle spielt.