Acridine orange stain of Mycobacterium leprae / 나학회지

The Ziehl-Neelson's AFB staining method was mainly used for the AFB observation of the diagnosis of leprosy. However, the fluorescent stain performs better and allows the detection of more positive smears. The limitation for its widespread use has been the high cost for fluorescent microscopes. Novel light-emitting diodes (LED) are inexpensive solutions for fluorescent microscopes, and thus fluorescent stain may be a cost-effective step to improve the diagnosis of leprosy in resource-poor countries. And the comparison of auramine and acridine orange for staining of acid-fast bacteria was showed significantly more acid-fast rods after using acridine orange and the number of "false positive" results was somewhat higher on auramine staining. So acridine orange offers a good alternative to auramine which is considered carcinogenic. This study evaluated the comparison of the Ziehl-Neelson's AFB stain and the acridine orange stain in the skin smear based on PCR. As PCR results were taken as gold standard, results of the study revealed that the sensitivity of Ziehl-Neelson's AFB stain was 50% and that of acridine orange stain was 92.2%. This study confirmed that the fluorescence stain method is more sensitive than the Ziehl-Neelsen's staining method. It is suggested that the training of laboratory technicians on fluorescence microscopy should be scaled up for increased disease control.

Blood culture gram stain, acridine orange stain and direct sensitivity-based antimicrobial therapy of bloodstream infection in patients with trauma.

Purpose: The purpose of this study was to ascertain if the simple practice of Gram stain, acridine orange stain and direct sensitivity determination of positive blood culture bottles could be used to guide early and appropriate treatment in trauma patients with clinical suspicion of sepsis. The study also aimed to evaluate the error in interpreting antimicrobial sensitivity by direct method when compared to standard method and find out if specific antibiotic-organism combination had more discrepancies. Findings from consecutive episodes of blood stream infection at an Apex Trauma centre over a 12-month period are summarized. Materials and Methods: A total of 509 consecutive positive blood cultures were subjected to Gram staining. AO staining was done in BacT/ALERT-positive Gram-stain negative blood cultures. Direct sensitivity was performed from 369 blood culture broths, showing single type of growth in Gram and acridine orange staining. Results of direct sensitivity were compared to conventional sensitivity for errors. Results: No 'very major' discrepancy was found in this study. About 5.2 and 1.8% minor error rates were noted in gram-positive and gram-negative bacteria, respectively, while comparing the two methods. Most of the discrepancies in gram-negative bacteria were noted in β lactam - β lactamase inhibitor combinations. Direct sensitivity testing was not reliable for reporting of methicillin and vancomycin resistance in Staphylococci. Conclusions: Gram stain result together with direct sensitivity testing is required for optimizing initial antimicrobial therapy in trauma patients with clinical suspicion of sepsis. Gram staining and AO staining proved particularly helpful in the early detection of candidaemia.

Comparison of Usefulness of Laboratory Diagnosis in Ancanthamoeba Keratitis

Laboratory diagnostic methods, applied for the diagnosis of Acanthamoeba Keratitis, were evaluated for their usefulness in 16 patients of suspicious Acanthamoeba keratitis. Wet smear, Acridine orange(AO) stain, Gram stain and culture on nonnuturent agar plate were routinely used in all patients, and among them, and used saline of 7 contact lens not ideal for the corneal scraping specimens. AO and Gram stains were very useful in the identification of acanthamoeba, and culture on nonnutrient agar plates was essential to confirm this infection. Light and electron microscopic examinations were also useful in patients with negative results of ordinary diagnostic techniques. Suspicion of Acanthamoeba infection in patients that are recalcitrant to antibiotic treatment or related to contact lens wear, is the mont important step for the diagnosis of Acanthamoeba Keratitis. And also examination of corneal specimens by experienced observer is prerequisite for the accurate diagnosis of Acanthamoeba keratitis.

Comarison of Acridine Orange and Gram Stains in the Diagnosis of Infectious Keratitis

We assessed the comparatice sensitivity and specificity of acridine orange and Gram stains of corneal scrapings from 29 cases of presumed infectious keratitis. The corneal scrapings were placed on two clear glass slides and allowed to air dry. The slides were fixed in 95% methanol for 2 minutes and each slide was stained by Gram and acridine orange stains respectively. Culture was done with another corneal scraping. Cultures were positive in 19 of 29 cases(66%). Among them 14 cases (74%) were positive in Gram stain and 18 cases (95%) were positive in acridine orange stain. So the sensitivity of acridine orange was greater than that of Gram stain. In the specificity, Gram stain (80%) was better than acridine orange stain(50%). This study demonstrates acridine orange stain as well as gram stain is useful as a simple, rapid screening test for the diagnois of suspected infectious keratitis.