Browsing by Author "Elswaifi, Shaadi F."

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    Automatic Detection and Characterization of Parasite Eggs by Image Processing
    Ostergaard, Lindsey Eubank (Virginia Tech, 2013-08-26)
    The accurate identification of parasites allows for the quick diagnosis and treatment of infections. Current state-of-the-art identification techniques require a trained technician to examine prepared specimens by microscope or other molecular methods. In an effort to automate the process and better facilitate the field identification of parasites, approaches are developed to utilize LabVIEW and MATLAB, which are commercially available image processing software packages, for parasite egg identification. The goal of this project is to investigate different image processing techniques and descriptors for the detection and characterization of the following parasite eggs: Ascaris lumbricoides, Taenia sp., and Paragonimus westermani. One manual approach and four automated approaches are used to locate the parasite eggs and gather parasite characterization data. The manual approach uses manual measurements of the parasite eggs within the digital images. The four automated approaches are LabVIEW Vision Assistant scripts, MATLAB separation code, MATLAB cross-section grayscale analysis, and MATLAB edge signature analysis. Forty-four separate measurements were analyzed through the four different approaches. Two types of statistical tests, single factor global Analysis of Variance (ANOVA) test and Multiple Comparison tests, are used to demonstrate that parasite eggs can be differentiated. Thirty-six of the measurements proved to be statistically significant in the differentiation of at least two of the parasite egg types. Of the thirty-six measurements, seven proved to be statistically significant in the differentiation of all three parasite egg types. These results have shown that it is feasible to develop an automated parasite egg detection and identification algorithm through image processing. The automated image processing techniques have proven successful at differentiating parasite eggs from background material. This initial research will be the foundation for future software structure, image processing techniques, and measurements that should be used for automated parasite egg detection.
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    Case Report Chronic Microsporidial Enteritis in a Missionary from Mozambique
    Palmieri, James R.; Elswaifi, Shaadi F.; Lindsay, David S.; Junko, Gretchen; Callahan, Cathy (American Society for Tropical Medicine & Hygiene, 2010-11-01)
    Microsporidiosis often occurs in immunocompromised persons but may also occur in those who are immunocompetent. Infection by Microsporidia involves a variety of organs and systems, most notably, intestine, lung, kidney, brain, sinuses, muscle, and eyes. Enterocytozoon bieneusi and Encephalitozoon intestinalis are associated with gastroenteritis, and Enterocytozoon hellem and Encephalitozoon cuniculi are associated with keratoconjunctivitis. We report a case of chronic microsporidiosis in a 28-year-old woman missionary from Mozambique who came to our diagnostic laboratory with nausea, lower abdominal pain, and frequent bowel movements. Over two years, the patient was clinically assessed and treated for malaria and giardiasis without laboratory diagnosis while in Mozambique. Identification of the causative agent of her condition was not attempted during the course of her illness in Mozambique. Furthermore, adverse effects of malaria and giardiasis medications may have exacerbated the chronic illness in this patient and mimicked chronic microsporidiosis.
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    The role of lipooligosaccharide phosphorylcholine in colonization and pathogenesis of Histophilus somni in cattle
    Elswaifi, Shaadi F.; Scarratt, W. Kent; Inzana, Thomas J. (Biomed Central, 2012-06-07)
    Histophilus somni is a Gram-negative bacterium and member of the Pasteurellaceae that is responsible for respiratory disease and other systemic infections in cattle. One of the bacterium’s virulence factors is antigenic phase variation of its lipooligosaccharide (LOS). LOS antigenic variation may occur through variation in composition or structure of glycoses or their substitutions, such as phosphorylcholine (ChoP). However, the role of ChoP in the pathogenesis of H. somni disease has not been established. In Haemophilus influenzae ChoP on the LOS binds to platelet activating factor on epithelial cells, promoting bacterial colonization of the host upper respiratory tract. However, ChoP is not expressed in the blood as it also binds C-reactive protein, resulting in complement activation and killing of the bacteria. In order to simulate the susceptibility of calves with suppressed immunity due to stress or previous infection, calves were challenged with bovine herpes virus-1 or dexamethazone 3 days prior to challenge with H. somni. Following challenge, expression of ChoP on the LOS of 2 different H. somni strains was associated with colonization of the upper respiratory tract. In contrast, lack of ChoP expression was associated with bacteria recovered from systemic sites. Histopathology of cardiac tissue from myocarditis revealed lesions containing bacterial clusters that appeared similar to a biofilm. Furthermore, some respiratory cultures contained substantial numbers of Pasteurella multocida, which were not present on preculture screens. Subsequent biofilm experiments have shown that H. somni and P. multocida grow equally well together in a biofilm, suggesting a commensal relationship may exist between the two species. Our results also showed that ChoP contributed to, but was not required for, adhesion to respiratory epithelial cells. In conclusion, expression of ChoP on H. somni LOS contributed to colonization of the bacteria to the host upper respiratory tract, but phase variable loss of ChoP expression may help the bacteria survive systemically.