Purification of Rickettsia rickettsi by density-gradient zonal centrifugation

1974 ◽  
Vol 20 (11) ◽  
pp. 1523-1527 ◽  
Author(s):  
R. L. Anacker ◽  
R. K. Gerloff ◽  
L. A. Thomas ◽  
R. E. Mann ◽  
W. R. Brown ◽  
...  
Keyword(s):  
Density Gradient ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Dry Weight ◽  
Sucrose Density Gradient ◽  
Yolk Sac ◽  
Rocky Mountain Spotted Fever ◽  
L Cells ◽  
Extraneous Material ◽  
Chicken Eggs

Rocky Mountain spotted fever rickettsiae, cultivated either in yolk sacs of embryonated chicken eggs or in mouse L cells, were purified by centrifugation through a linear sucrose density gradient in a zonal rotor. Under the conditions of the experiments the rickettsiae banded at a density of about 1.21. Intact organisms with what appeared to be large translucent capsules were found in this band. The degree of purity was high because yolk sac contamination was not detected in rickettsial suspensions derived from embryonated eggs, and little extraneous material was observed by electron microscopy in suspensions obtained from either host. About 4 × 108 rickettsial particles were recovered from each gram of yolk sac and 2 × 1010 particles from each gram of L cells, a 50-fold difference. Each milligram dry weight of purified rickettsiae contained about 1 × 1010 particles.

scholarly journals Comparison of three rocky mountain spotted fever vaccines

1975 ◽  
Vol 2 (4) ◽  
pp. 300-304
Author(s):  
R H Kenyon ◽  
L S Sammons ◽  
C E Pedersen
Keyword(s):  
Chicken Embryo ◽  
Rhesus Monkeys ◽  
Protective Efficacy ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Embryo Cell ◽  
Yolk Sac ◽  
Rocky Mountain Spotted Fever ◽  
Duck Embryo ◽  
Chicken Embryo Cell

Growth of Rocky Mountain spotted fever (RMSF) rickettsiae in duck embryo cell (DEC) cultures and chicken embryo cell (CEC) cultures was evaluated. Experimental lots of duck embryo cell- and chicken embryo cell-grown Rocky Mountain spotted fever vaccines and a commercial lot of yolk sac-grown vaccine were compared for protective efficacy in rhesus monkeys. Incidence and magnitude of antibody response, febrile response, and rickettsemia, as well as incidence of fatalities, suggested that both cell culture-derived vaccines were more immunogenic than the yolk sac-grown vaccine.

Complement Fixing Antibody Response of Man to Yolk Sac-Grown Rocky Mountain Spotted Fever Vaccine

1968 ◽  
Vol 128 (1) ◽  
pp. 191-195 ◽  
Author(s):  
A. B. Cohen ◽  
I. B. Fabrikant ◽  
J. N. Hatgi ◽  
C. L. Wisseman
Keyword(s):  
Antibody Response ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Yolk Sac ◽  
Rocky Mountain Spotted Fever

Mitbringsel aus den Ferien

Praxis ◽  
2005 ◽  
Vol 94 (47) ◽  
pp. 1869-1870
Author(s):  
Balestra ◽  
Nüesch
Keyword(s):  
Rocky Mountains ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Rickettsia Conorii ◽  
Rocky Mountain Spotted Fever ◽  
Klinische Diagnose ◽  
Rickettsia Rickettsii

Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.

Mosquito and Tick-borne Illnesses in the United States. Guidelines for the Recognition and Empiric Treatment of Zoonotic Diseases in the Wilderness.

2019 ◽  
Vol 19 (3) ◽  
pp. 238-257
Author(s):  
Suresh Antony
Keyword(s):  
United States ◽  
Lyme Disease ◽  
Spotted Fever ◽  
Disease Process ◽  
Rocky Mountain ◽  
The United States ◽  
Health Care Facilities ◽  
Diagnostic Tools ◽  
Rocky Mountain Spotted Fever ◽  
Number Of Patients

Background:In the United States, tick-borne illnesses account for a significant number of patients that have been seen and treated by health care facilities. This in turn, has resulted in a significant morbidity and mortality and economic costs to the country.Methods:The distribution of these illnesses is geographically variable and is related to the climate as well. Many of these illnesses can be diagnosed and treated successfully, if recognized and started on appropriate antimicrobial therapy early in the disease process. Patient with illnesses such as Lyme disease, Wet Nile illness can result in chronic debilitating diseases if not recognized early and treated.Conclusion:This paper covers illnesses such as Lyme disease, West Nile illness, Rocky Mountain Spotted fever, Ehrlichia, Tularemia, typhus, mosquito borne illnesses such as enteroviruses, arboviruses as well as arthropod and rodent borne virus infections as well. It covers the epidemiology, clinical features and diagnostic tools needed to make the diagnosis and treat these patients as well.

scholarly journals Tick-Borne-Associated Illnesses in the Pediatric Intensive Care Unit

2020 ◽  
Vol 15 (06) ◽  
pp. 269-275
Author(s):  
Kaila Lessner ◽  
Conrad Krawiec
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Pediatric Intensive Care Unit ◽  
Early Recognition ◽  
Spotted Fever ◽  
Pediatric Intensive Care ◽  
Rocky Mountain ◽  
Rocky Mountain Spotted Fever ◽  
Life Threatening ◽  
Human Ehrlichiosis

AbstractWhen unrecognized and antibiotic delay occurs, Lyme disease, Rocky Mountain–spotted fever, babesiosis, and human ehrlichiosis and anaplasmosis can result in multiorgan system dysfunction and potentially death. This review focuses on the early recognition, evaluation, and stabilization of the rare life-threatening sequelae seen in tick-borne illnesses that require admission in the pediatric intensive care unit.

scholarly journals Dermacentor variabilis is the Predominant Dermacentor spp. (Acari: Ixodidae) Feeding on Dogs and Cats Throughout the United States

2021 ◽  
Author(s):  
Kathryn T Duncan ◽  
Meriam N Saleh ◽  
Kellee D Sundstrom ◽  
Susan E Little
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Dermacentor Variabilis ◽  
Western United States ◽  
Its2 Region ◽  
Rrna Gene ◽  
Rocky Mountain Spotted Fever ◽  
Dermacentor Albipictus

Abstract Throughout North America, Dermacentor spp. ticks are often found feeding on animals and humans, and are known to transmit pathogens, including the Rocky Mountain spotted fever agent. To better define the identity and distribution of Dermacentor spp. removed from dogs and cats in the United States, ticks submitted from 1,457 dogs (n = 2,924 ticks) and 137 cats (n = 209 ticks) from veterinary practices in 44/50 states from February 2018-January 2020 were identified morphologically (n = 3,133); the identity of ticks from regions where Dermacentor andersoni (Stiles) have been reported, and a subset of ticks from other regions, were confirmed molecularly through amplification and sequencing of the ITS2 region and a 16S rRNA gene fragment. Of the ticks submitted, 99.3% (3,112/3,133) were Dermacentor variabilis (Say), 0.4% (12/3,133) were D. andersoni, and 0.3% (9/3,133) were Dermacentor albipictus (Packard). While translocation of pets prior to tick removal cannot be discounted, the majority (106/122; 87%) of Dermacentor spp. ticks removed from dogs and cats in six Rocky Mountain states (Montana, Idaho, Wyoming, Nevada, Utah, and Colorado) were D. variabilis, suggesting this species may be more widespread in the western United States than is currently recognized, or that D. andersoni, if still common in the region, preferentially feeds on hosts other than dogs and cats. Together, these data support the interpretation that D. variabilis is the predominant Dermacentor species found on pets throughout the United States, a finding that may reflect recent shifts in tick distribution.

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