Detection of B. anthracis

B. anthracis are usually used to diagnose anthrax however, previous antibiotic treatment will affect culture yield and Gram stain identification of the bacteria. Immunohistochemistry has demonstrated high sensitivity and specihcity for the detection of B. anthracis in skin biopsies, pleural biopsies, transbronchial biopsies, and pleural fluids (see Fig. 

Fig. 17 Detection of B. anthracis from murine blood, (a) Detector responses during all three stages of sample processing and analysis are portrayed in terms of total analysis time. The SPE trace (green) was taken from off-line DNA extraction of the same murine sample and is representative of the total DNA concentration observed in a typical extraction. The temperature (blue) and fluorescence intensity (black) represent on-line data, with a total analysis time <24 min. Three sequential injections and separations were carried out to ensure the presence of amplified product, (b) Fluorescence data from an integrated analysis of a blank sample (no DNA) control with marker peaks labeled. The inset represents valve actuation during co-injection, with the PR and MR pumping inlets indicated by the arrows, (c) Zoomed view of the first separation shown in (a), with the product peak marked. The second and third runs are overlaid with the time axis cropped. Inset shows the sizing curve of inverse migration time vs. logfbase pairs) with both the sizing standard peaks (open diamonds) and product (square) plotted for all three runs shown in (a). From these data, the product was 211 2 bp. Reproduced from [10] with permission...

FIGURE 36.13 (a) Integrated microchip used for the detection of B. anthracis infection in murine blood. 

On the other hand, these water molecules are only weakly bound to the metal centre and they are readily substituted by DPA when present in solution, resulting in a significant enhancement of the complex emission intensity. The authors showed a linear correlation between the maximum emission intensity of the nanosensor and the concentration of CaDPA in solution in the range 0.6-600 nM with a detection limit down to 0.2 nM. Therefore it was very sensitive but also very selective over other aromatic ligands. The rapid and ultrasensitive detection of B. anthracis spores in water was also helped by the ratiometric nature of the material since the... 

Anthrax is an infection disease caused by Bacillus anthracis that requires medical attention within 24-48 hours after initial inhalation of more than 10 B, anthracis spores (/). Therefore, the rapid detection of B, anthracis spores in the environment prior to infection is an extremely important goal for human safety. Structurally, a spore consists of a central core cell surrounded by various protective layers. CaDPA is located in these protective layers and accounts for -10% of the spore s dry weight (2) making it is a useful biomarker for bacillus spores (5). 

Acute and convalescent serum samples for serological ELISA testing should be collected for diagnosis. The CDC developed an ELISA for the detection of B. anthracis PA using immunoglobulin G (IgG) antibodies in response to the bioterrorist anthrax plot in 2001. ELISA proved extremely useful in the detection of cutaneous and inhalational anthrax (Quinn et al., 2002). The diagnostic sensitivity and diagnostic specificity for this test are 97.6% and 94.2%, respectively. 

Figure 7.11 (A) Experimental design, depicting the organization of the DNA oligomers on SiFs used for the detection of Bacillus anthracis. (B) Emission spectra of the TAMRA-Oligo as a function of B. anthracis exosporium concentration after 30 s low power microwave heating. (C) Plot of the fluorescence emissicm intensity at 585 tun for TAMRA-Oligo as a function of target concentration. Data for B. cereus (a non-causative strain) is also shown for con arison. Ad ed fi-om reference 52.

Yamada S, Ohashi E, Agata N, Venkateswaran K (1999) Cloning and nucleotide sequence analysis of gyrB of Bacillus cereus, B. thuringiensis, B. mycoides, and B. anthracis and their application to the detection of B. cereus in rice. Appl Environ Microbiol 65 1483-149 Yamamoto S, Harayama S (1995) PCR amplification and direct sequencing of gyrB genes with universal primers and their application to the detection and taxonomic analysis of Pseudomonas putida strains. Appl Environ Microbiol 61 1104-1109... 

Shen W, Lakshmanan RS, Mathison LC, Petrenko VA, Chin BA (2009) Phage coated magnetoelastic micro-biosensOTs for real-time detection of Bacillus anthracis spores. Sens Actuators B 137 501-506... 

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