Comparison of acridine orange and Gram stains for detection of microorganisms in cerebrospinal fluid and other clinical specimens

Lauer, Brian A.; Reller, L. Barth; Mirrett, Stanley

doi:10.1128/jcm.14.2.201-205.1981

Cited by 104 publications

(43 citation statements)

References 10 publications

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“…Buffy coat smears stained with A 0 stain were more sensitive than those stained with Gram's stain ( p < 0.005). Dilution studies have shown the lower limits of sensitivity of A 0 to be lo4 colony forming units/ml and of Gram's stain to be lo5 colony forming units/ml (8,9). A 0 and Gram-stained buffy coat smears have had limited success in older children (1 0) and adults (1 l), as compared to neonates.…”

Section: Discussionmentioning

confidence: 99%

Superiority of acridine orange‐stained buffy coat smears for diagnosis of partially treated neonatal septicemia

Mathur

Saxena

Sarkar³

et al. 1993

Acta Paediatrica

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Early diagnosis of neonatal septicemia is a vexing problem because of its non-specific clinical picture. Many of the neonates with septicemia reaching a referral centre have already been exposed to antibiotics and their blood cultures are often sterile. Scarcity of studies evaluating acridine orange-stained buffy coat smears in detecting neonatal septicemia after administration of antibiotics prompted us to undertake this study. The population studied consisted of 34 cases of neonatal septicemia with positive blood cultures and/or positive buffy coat smears (of these 25 had a positive blood culture) and 25 neonates with a clinical course not suggestive of any infection. Venous blood was drawn for culture, preparation of buffy coat smears, blood counts and micro ESR. The culture and smears were repeated after administration of antibiotics for 48-72 h. Acridine orange stain was the most sensitive test and was significantly more sensitive than Gram's stain (p < 0.005). After the administration of antibiotics, acridine orange was significantly more sensitive than Gram's stain and blood culture (p < 0.05).

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Section: Discussionmentioning

confidence: 99%

Superiority of acridine orange‐stained buffy coat smears for diagnosis of partially treated neonatal septicemia

Mathur

Saxena

Sarkar³

et al. 1993

Acta Paediatrica

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“…Therefore, a more sensitive means for detecting those organisms that are present at a low level or that are less visible after Gram staining has been recognized. For example, acridine orange, Wayson, and other staining procedures have shown enhanced sensitivity for observing organisms (1,3,7). However, these stains do not increase the number of organisms on the slide.…”

Section: Discussionmentioning

confidence: 99%

Clinical and laboratory analyses of cytospin-prepared Gram stains for recovery and diagnosis of bacteria from sterile body fluids

1992

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The smear of a clinical specimen provides essential laboratory information that is used to make therapeutic decisions. For this study, smears were made by centrifugation in a Beckman Microfuge 11 (Beckman Instruments, Palo Alto, Calif.) and in parallel by using a Cytospin 2 apparatus (Shandon Inc., Pittsburgh, Pa.). Of 350 consecutive body fluid specimens examined, 50 (14.0%) grew bacteria. Both methods were culture and smear positive for 24 (6.9%) specimens; 18 (5.1%) specimens were cytocentrifuge smear positive, culture positive, and high-speed centrifugation (HSC) negative; 3 (0.8%) were culture negative and positive by both smear methods; and 1 (0.2%) was HSC smear positive, culture positive, and cytocentrifuge negative. Seven (2.0%) specimens were culture positive and negative by both smear methods. Clinically, cytocentrifuge preparations showed greater sensitivity for culture-positive specimens and a closer correlation with the CFU per milliliter than HSC did, resulting in a greater ability to treat patients with specific therapies. In addition, analysts needed to examine only a 6-mm-diameter area on the slide, cells and microbes were somewhat larger and more regular in appearance, and smears stained more uniformly. Because of the increased clinical and laboratory utility of the cytocentrifuge, its use is recommended in clinical microbiology laboratories for all sterile body fluid specimens.Rapid diagnosis by Gram staining for a suspected infectious organism from a sterile body fluid is a major responsibility of our Clinical Microbiology Laboratory. In addition to suggesting a diagnosis, it guides clinicians in the choice of antibiotics. This is especially critical in patients with lifethreatening diseases such as meningitis, peritonitis, and obstetric infections, in which the clinical efficacy is dependent on the therapeutic intervention that is used. Because the concentration of microorganisms in body fluid specimens may be low and/or the volume of specimen submitted for study may be extremely low, a technique for concentrating body fluids is recommended for body fluids that are to be used in smears and cultures (5,6,9). In the Hematology and Cytology laboratories, a cytocentrifuge technique is commonly used to prepare body fluid specimen smears when the intent is to observe the morphologies of the cells (2,4,8). These methods sometimes demonstrate organisms that were not observed in the smears prepared from the same specimens by the Clinical Microbiology laboratory. Because of this phenomenon, we undertook an investigation into the sensitivity and specificity of smears prepared with the cytocentrifuge compared with those of smears prepared by the high-speed centrifugation (HSC) method currently used in our laboratory. Both methods were evaluated for laboratory and clinical utility. MATERIALS AND METHODSSpecimens. Three hundred fifty consecutive sterile body fluids from sterile body sites submitted to the Clinical Microbiology Laboratory for evaluation were included in this study. Specimens were processed...

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“…After drying overnight, the slides were stained by gently placing three drops of 0.01% acridine orange solution (in pH 3.5 acetate buffer) and then gently rinsed with filtersterilized distilled water and returned to the microscope slide box to dry in the dark (Lauer et al, 1981;Siering and Ghiorse, 1997).…”

Section: -3: Environmental Sinter Collection Preparation and Examinmentioning

confidence: 99%

Paleological and Ecological Impacts of Virus Silicification

Laidler¹

2000

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Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses had not been, prior to this work.Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained during the short period of silicification (48 hours), and a clear elemental signature of silicon and phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDX). However, the EDX signature of silicified virus was not sufficiently distinct from that of cell membrane or phosphate minerals for that technique to be used to discover viral remains in hot spring mineral deposits.Having shown that bacteriophage T4 can be silicified, it was then determined that the impact of silica exposure on infectivity varied widely between different viruses. The effect on infectivity did not appear to be related to virus size or morphology. In addition, the impact on infectivity was at least partially reversible, indicating that it was caused, at least in part, by occluding infection-related structures on the virus, rather than destruction or denaturation of the virus.Those viruses which showed a decline in infectivity with silica exposure also showed increased resistance to desiccation after being exposed to silica, which has implication for ii long-range virus dispersal. The desiccation resistance was proportional to the degree that silicification reduced infectivity in that virus. Desiccation resistance also declined with prolonged exposure to drying, suggesting that the mechanism was due to the silica coating helping to retain water rather than replacing the hydrogen bonding of water.Virus dispersal is critical for both the spread of disease and the diverse roles that viruses play in Earth ecology. However, the mechanisms of host-independent virus dispersal are poorly understood and hotly debated. These experiments showed that, under mild conditions, diverse viruses can be coated in silica and that silica coating provides some, if not most, viruses with remarkable desiccation tolerance. Virus silicification thus provides a potential mechanism for global dispersal of viruses that could not otherwise tolerate the desiccation of wind-borne transportation.iii Acknowledgments:

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Comparison of acridine orange and Gram stains for detection of microorganisms in cerebrospinal fluid and other clinical specimens

Cited by 104 publications

References 10 publications

Superiority of acridine orange‐stained buffy coat smears for diagnosis of partially treated neonatal septicemia

Superiority of acridine orange‐stained buffy coat smears for diagnosis of partially treated neonatal septicemia

Clinical and laboratory analyses of cytospin-prepared Gram stains for recovery and diagnosis of bacteria from sterile body fluids

Paleological and Ecological Impacts of Virus Silicification

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