Staining of bacteria

Mounting and Staining of Bacteria.—The mounting and staining of bacteria may be accomplished as follows ... 

Interest has been recently rekindled in modifications of the 4"-hydroxyl group on the neutral sugar cladinose 4"-0-acyl derivatives of erythromycin have been synthesized which did not induce macrolide (i.e., MLS) resistance in inducibly-resistant strains of bacteria [55, 56]. In addition, other derivatives modified at the 4"-hydroxyl and/or 11,12-diol have demonstrated better activity than erythromycin against constitutively-resistant stains of bacteria [57, 58]. Although these results are intriguing, further research must be done to determine whether a macrolide can be discovered which possesses clinically useful activity against MLS-resistant bacteria. 

Webster, R. Simple staining of bacteria and fungi in hide, skin and leather. Stain Technol. 1983, 58, 315-318. 

Brunius, G. Technical aspects of the use of 3, 6 -diacetyl fluorescein for vital fluorescent staining of bacteria. Curr. Microbiol. 1980, 4, 321-323. 

Tay et al. (1974, 1979) have studied the mechanism of erosion of the dental silicate cement in service, finding that grooving occurs at the margin between the restoration and the tooth. Erosion exposes the cavity and provides sites for the accumulation of food debris and bacteria which can cause inflammation of the gingiva (Larato, 1971). It also leads to staining of the restoration (Bock, 1971 Kent, Lewis Wilson, 1973). 

B. Lundgren, Fluorescein diacetate as a stain of metabolically active bacteria in soil, Oikos 56 17 (1981). 

Ascitic fluid usually contains greater than 300 leukocytes/ mm3, and bacteria may be evident on Gram stain of a centrifuged specimen. 

Alternatively, a Gram stain vaginal smear may be used to diagnose BV using the Nugent criteria. This relies on estimating the proportions of bacteria morphotypes to provide a score between 0 and 10. A score of less than 4 is normal, 4 to 6 is intermediate, and greater than 6 is consistent with BV. 

Measurements show some variation depending upon the staining solution used and the method of application. In dried and fixed smears, the cell wall and slime layer do not stain with weakly staining dyes such as methylene blue but do stain with the intensely staining pararosaniline, new fuchsin, crystal violet, and methyl violet. The great majority of bacteria have been measured in fixed and stained preparations. In some instances dried, negatively stained smears have been used. Therefore, the method employed should be specified when measurements of bacteria are reported otherwise the results will be of doubtful v alue. 

Analysis of the structure of bacteria excludes the possibility that tails, flagella, or the thin wavy threads are live organs, or that they are in direct communication with the living parts of the cell. There is no evidence from either electron pictures or stained preparations that it is otherwise. 

Immuno-histochemical staining of intracellular bacteria in filarial nematodes has been obtained using antibodies against GroELand catalase (Henkle-Duhrsen etal., 1998 Hoerauf etal., 1999) the specificity of these antibodies is unknown, but it is expected to be low because both GroEL and catalase show high level of amino acid conservation throughout the proteobacteria. nd = not done. 

Infected body materials must be sampled, if at all possible or practical, before the institution of antimicrobial therapy, for two reasons. First, a Gram stain of the material may reveal bacteria, or an acid-fast stain may detect mycobacteria or actinomycetes. Second, a delay in obtaining infected fluids or tissues until after therapy is started may result in falsenegative culture results or alterations in the cellular and chemical composition of infected fluids. 

A standard urinalysis should be obtained in the initial assessment of a patient. Microscopic examination of the urine should be performed by preparation of a Gram stain of unspun or centrifuged urine. The presence of at least one organism per oil-immersion field in a properly collected uncentrifuged specimen correlates with more than 100,000 bacteria/mL of urine. 

Mycobacterium is a genus of bacteria that has characteristic cell walls and unusual staining properties. AIDS patients are most commonly infected with an atypical form of tuberculosis bacterium called Mycobacterium avium inter-cellulare. This bacterium does not normally cause disease in healthy people, but in AIDS patients, it may cause tuberculosis-like disease in the lungs. The infection can also involve numerous other tissues, such as the bone marrow, and bacteria may be present in the blood at very high levels. Patients with this opportunistic infection will have fevers and low number of white blood cells. These infections are often resistant to drugs. 

Bacterial pigments. Some bacteria commonly found in caries lesions are known to produce pigments. For example, the black staining of plaque is related with Actinomyces (Slots, 1974), but its chemical nature remains unknown. Black pigmented Prevotella produces both iron sulphide and heme pigments (Shah et ah, 1979). In addition, Propionibacterium forms porphyrins (Lee et al., 1978). Bacterial iron-binding peptides, which can contribute to discoloration, increase in the saliva of subjects with a high caries frequency (Nordh, 1969). 

A clinical diagnosis of bacterial meningitis was made. Therapy was started immediately because of the life-threatening nature of the illness. He was empirically treated with ceftriaxone and vancomycin, intravenously. A short time later, a Gram stain of his CSF revealed that the bacteria were Gram-positive cocci. Accordingly, the empiric... 

Like the mycoplasma, the E. coli cell is bounded by an 8-nm membrane which consists of -50% protein and 50% lipid. When "stained" (e.g., with permanganate) for electron microscopy, this single membrane appears as two very thin (2.0 nm) dark lines separated by an unstained center band (-3.5 nm) (Fig. 1-4 see also Fig. 8-4). Single membranes of approximately the same thickness and staining behavior occur in all cells, both of bacteria and of eukaryotes. 

The development of the "sulfa drugs,"a c derivatives of sulfanilamide, originated with studies of the staining of protozoal parasites by Paul Erhlich. In 1932 it was shown that the red dye 2,4-diamino-azobenzene-4 -sulfonamide (Prontosil) dramatically cured systemic infections by gram-positive bacteria. Subsequent studies revealed that bacteria converted... 

---