Amblyomma maculatum (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of Rickettsia parkeri, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in A. maculatum based on rickettsial ompA gene PCR. Our results showed A. maculatum harbors R. parkeri, R. amblyommii, and R. endosymbiont of A. maculatum. While only R. parkeri was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of R. parkeri was further confirmed by probe based qPCR assay. We found R. parkeri infection rate ranged 12-40% in field collected ticks. We also provided evidence of R. parkeri infection transovarially and transstadially transmitted in A. maculatum. We used a pyrosequencing approach to further study all possible bacterial diversity residing in field collected A. maculatum. The huge bacterial profiling in A. maculatum provided the basis of Amblyomma-bacterial interactions particularly in relation to R. parkeri. On the other side, we observed cystatins temporal transcriptional expression in A. maculatumacross the blood meal cycle and our finding suggested their importance during blood feeding. Further, we saw R. parkeri differentially regulates gene expressions of cystatins in A. maculatum, suggesting a possible role of cystatins in R. parkeri infection in ticks. This study encourages further study to assess the exact relationship of R. parkeri with bacterial diversity in A. maculatum and cystatins role during tick blood feeding and R. parkeri transmission.
Link to doctoral dissertation - http://aquila.usm.edu/dissertations/1381/
","abstract_html":"<p><em>Amblyomma maculatum</em> (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of <em>Rickettsia parkeri</em>, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in <em>A. maculatum</em> based on rickettsial <em>ompA</em> gene PCR. Our results showed <em>A. maculatum </em>harbors <em>R. parkeri, R. amblyommii, </em>and <em>R. endosymbiont of A. maculatum.</em> While only <em>R. parkeri</em> was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of <em>R. parkeri</em> was further confirmed by probe based qPCR assay. We found <em>R. parkeri</em> infection rate ranged 12-40% in field collected ticks. We also provided evidence of <em>R. parkeri </em>infection transovarially and transstadially transmitted in <em>A. maculatum</em>. We used a pyrosequencing approach to further study all possible bacterial diversity residing in field collected <em>A. maculatum</em>. The huge bacterial profiling in <em>A. maculatum</em> provided the basis of Amblyomma-bacterial interactions particularly in relation to <em>R. parkeri</em>. On the other side, we observed cystatins temporal transcriptional expression in <em>A. maculatum</em>across the blood meal cycle and our finding suggested their importance during blood feeding. Further, we saw <em>R. parkeri</em> differentially regulates gene expressions of cystatins in <em>A. maculatum,</em> suggesting a possible role of cystatins in <em>R. parkeri</em> infection in ticks. This study encourages further study to assess the exact relationship of <em>R. parkeri</em> with bacterial diversity in <em>A. maculatum</em> and cystatins role during tick blood feeding and <em>R. parkeri</em> transmission.</p> <p>Link to doctoral dissertation - http://aquila.usm.edu/dissertations/1381/</p>","abstract_has_math":false,"creators":["Budachetri, Khemraj"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Masters Thesis","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":["Shahid Karim","Mohamed Elasri","Fengwei Bai"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-08-01T07:00:00Z","date_published":"2013-08-01T07:00:00Z","updated_at":"2026-07-24T05:44:41Z","subjects":["Amblyomma maculatum","gulf coast tick","rickettsia parkeri","spotted fever","human rickettsiosis","Biology","Disorders of Environmental Origin","Medicine and Health Sciences","Parasitic Diseases"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://aquila.usm.edu/masters_theses/272","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Shahid Karim","Mohamed Elasri","Fengwei Bai"]},{"key":"dc:creator","label":"Author","values":["Budachetri, Khemraj"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2017-01-23T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Amblyomma maculatum","gulf coast tick","rickettsia parkeri","spotted fever","human rickettsiosis","Biology","Disorders of Environmental Origin","Medicine and Health Sciences","Parasitic Diseases"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://aquila.usm.edu/masters_theses/272"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Amblyomma maculatum (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of Rickettsia parkeri, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in A. maculatum based on rickettsial ompA gene PCR. Our results showed A. maculatum harbors R. parkeri, R. amblyommii, and R. endosymbiont of A. maculatum. While only R. parkeri was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of R. parkeri was further confirmed by probe based qPCR assay. We found R. parkeri infection rate ranged 12-40% in field collected ticks. We also provided evidence of R. parkeri infection transovarially and transstadially transmitted in A. maculatum. We used a pyrosequencing approach to further study all possible bacterial diversity residing in field collected A. maculatum. The huge bacterial profiling in A. maculatum provided the basis of Amblyomma-bacterial interactions particularly in relation to R. parkeri. On the other side, we observed cystatins temporal transcriptional expression in A. maculatumacross the blood meal cycle and our finding suggested their importance during blood feeding. Further, we saw R. parkeri differentially regulates gene expressions of cystatins in A. maculatum, suggesting a possible role of cystatins in R. parkeri infection in ticks. This study encourages further study to assess the exact relationship of R. parkeri with bacterial diversity in A. maculatum and cystatins role during tick blood feeding and R. parkeri transmission.
Link to doctoral dissertation - http://aquila.usm.edu/dissertations/1381/
"]},{"key":"dc:title","label":"Title","values":["An Insight Into the Microbial Diversity and Expression of Cysteine Protease Inhibitors (Cystatin) in Rickettsia parkeri Infected Amblyomma maculatum"]}]}],"canonical_facts":{"dc:contributor":["Shahid Karim","Mohamed Elasri","Fengwei Bai"],"dc:creator":["Budachetri, Khemraj"],"dc:date.available":["2017-01-23T08:00:00Z"],"dc:description.abstract":["Amblyomma maculatum (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of Rickettsia parkeri, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in A. maculatum based on rickettsial ompA gene PCR. Our results showed A. maculatum harbors R. parkeri, R. amblyommii, and R. endosymbiont of A. maculatum. While only R. parkeri was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of R. parkeri was further confirmed by probe based qPCR assay. We found R. parkeri infection rate ranged 12-40% in field collected ticks. We also provided evidence of R. parkeri infection transovarially and transstadially transmitted in A. maculatum. We used a pyrosequencing approach to further study all possible bacterial diversity residing in field collected A. maculatum. The huge bacterial profiling in A. maculatum provided the basis of Amblyomma-bacterial interactions particularly in relation to R. parkeri. On the other side, we observed cystatins temporal transcriptional expression in A. maculatumacross the blood meal cycle and our finding suggested their importance during blood feeding. Further, we saw R. parkeri differentially regulates gene expressions of cystatins in A. maculatum, suggesting a possible role of cystatins in R. parkeri infection in ticks. This study encourages further study to assess the exact relationship of R. parkeri with bacterial diversity in A. maculatum and cystatins role during tick blood feeding and R. parkeri transmission.
Link to doctoral dissertation - http://aquila.usm.edu/dissertations/1381/
"],"dc:identifier":["https://aquila.usm.edu/masters_theses/272"],"dc:subject":["Amblyomma maculatum","gulf coast tick","rickettsia parkeri","spotted fever","human rickettsiosis","Biology","Disorders of Environmental Origin","Medicine and Health Sciences","Parasitic Diseases"],"dc:title":["An Insight Into the Microbial Diversity and Expression of Cysteine Protease Inhibitors (Cystatin) in Rickettsia parkeri Infected Amblyomma maculatum"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Masters Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:44:41Z"}