scholarly journals MORPHOLOGICAL STRUCTURE OF RICKETTSIAE

1943 ◽  
Vol 77 (4) ◽  
pp. 355-358 ◽  
Author(s):  
Harry Plotz ◽  
Joseph E. Smadel ◽  
Thomas F. Anderson ◽  
Leslie A. Chambers
Keyword(s):  
Vaccinia Virus ◽  
Q Fever ◽  
Spotted Fever ◽  
Morphological Structure ◽  
Rocky Mountain ◽  
Rocky Mountain Spotted Fever ◽  
Dense Granules ◽  
Endemic Typhus ◽  
Typhus Fever

The morphological structures of the rickettsiae of epidemic and endemic typhus fever, Rocky Mountain spotted fever, and Q fever are similar to one another and to certain bacteria. The rickettsial organisms in common with the elementary bodies of vaccinia virus and all bacteria would appear to have a limiting membrane which surrounds a substance that seems to be protoplasmic in nature; numbers of dense granules are embedded in the inner protoplasm.

scholarly journals Serological Varieties of Typhus Fever

1931 ◽  
Vol 31 (2) ◽  
pp. 225-246 ◽  
Author(s):  
A. Felix ◽  
M. Rhodes
Keyword(s):  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Antigenic Relationship ◽  
Rocky Mountain Spotted Fever ◽  
Antigenic Variant ◽  
Serological Type ◽  
Endemic Typhus ◽  
Typhus Fever ◽  
Source Of Error

1. Fletcher and Lesslar's observations on two serological types of tropical typhus have been fully confirmed.2. The antigenic relationship between the indologenicB. proteusX 19 and the non-indologenic Kingsbury strain is of the same order as that obtaining between the X 19 and X 2 types ofB. proteusX.3. The Kingsbury strain is an antigenic variant derived from the original X 19 culture and represents another serological type ofB. proteusX. The symbol XK is suggested for this type.4. Sera from cases of classical European typhus and of endemic typhus of the United States of America and of Australia have been tested for the occurrence of main and group O agglutinins for the known types ofB. proteusX.5. H agglutination as source of error in the diagnosis of typhus cases is illustrated by some examples.6. Sera from cases of tsutsugamushi from Sumatra and Japan react with type XK like the Malayan cases of this disease described by Fletcher and co-workers.7. This latter reaction is of the order of group O agglutination. It is suggested that antigenically the virus of tsutsugamushi corresponds to another serological type ofB. proteusX which is yet unknown.8. The data published on the serum reactions in Rocky Mountain spotted fever and in the “fièvre exanthématique” of Marseilles are analysed. It is suggested that these two diseases represent further serological varieties of typhus.9. The significance hitherto attached to negative agglutination tests withB. proteusX and to negative cross-immunity tests obtained with some typhuslike diseases requires revision in the light of recent observations.

scholarly journals STUDIES ON TYPHUS FEVER

1931 ◽  
Vol 53 (4) ◽  
pp. 493-497 ◽  
Author(s):  
Hans Zinsser ◽  
M. Ruiz Castaneda
Keyword(s):  
Guinea Pigs ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Active Immunization ◽  
Rocky Mountain Spotted Fever ◽  
Typhus Fever

Guinea pigs can be immunized against Mexican typhus virus by peritoneal injections of formalinized Rickettsia material, provided sufficient amounts of the organisms are used. Our results in this respect are analogous to those of Spencer and Parker with carbolized virus of Rocky Mountain spotted fever. The Rickettsia suspensions appear to possess considerable toxicity. We do not wish to be misunderstood as implying that the results in guinea pigs offer anything more than a demonstration of the principle of active immunization with killed Rickettsiae. Application to man will have to be worked out, and preliminary to this, we are now attempting to apply the methods to a limited number of monkeys.

scholarly journals LOCALIZATION OF ANTIGEN IN TISSUE CELLS

1950 ◽  
Vol 91 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Albert H. Coons ◽  
John C. Snyder ◽  
F. Sargent Cheever ◽  
Edward S. Murray
Keyword(s):  
Spotted Fever ◽  
Rocky Mountain ◽  
Virus Antigen ◽  
Rocky Mountain Spotted Fever ◽  
Infected Monkey ◽  
Tissue Sections ◽  
Epidemic Typhus ◽  
Cotton Rats ◽  
Antigenic Material ◽  
Typhus Fever

Rickettsiae of epidemic typhus fever and Rocky Mountain spotted fever have been microscopically localized and identified in smears of exudates and tissue sections from infected cotton rats by means of homologous antibody labelled with fluorescein. Epidemic typhus has also been identified in smears from single infected human body lice. Mumps virus antigen has been microscopically localized in the parotid of the experimentally infected monkey by the same method. The antigenic material, probably active virus, was found in the cytoplasm of the acinar cells. Such infected acini were scattered irregularly throughout the gland. Some antigen could be seen in the lumens of the parotid ducts and small amounts were present in the cytoplasm of the epithelial cells lining the ducts.

RICKETTSIAL DISEASES OF ANIMALS TRANSMISSIBLE TO CHILDREN

PEDIATRICS ◽  
1958 ◽  
Vol 22 (2) ◽  
pp. 384-387
Author(s):  
Lauri Luoto
Keyword(s):  
Small Mammals ◽  
Q Fever ◽  
Natural Infection ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Amblyomma Americanum ◽  
Rocky Mountain Spotted Fever ◽  
Rickettsial Infections ◽  
Dog Tick ◽  
Rickettsial Diseases

BECAUSE rickettsial infections occur sporadically, pediatricians may not be as thoroughly familiar with them as they are with common diseases of children that are characterized by rash. Hence, the rickettsias are infrequently considered in the etiology of febrile exanthemas or fevers of undertermined origin. Rickettsial diseases of primary interest in this country are Rocky Mountain spotted fever, murine typhus, rickcttsialpox and Q fever. The agents causing these diseases exist as latent infections in arthropods and animals, and they are transmitted accidentally to man through well-defined channels of spread. An awareness of the epizootiology of rickettsial diseases in nature and of the means by which these agents are transmitted to man is helpful in establishing a diagnosis of a rickettsial disease. Therefore, salient features of the natural cycles of infection which may suggest a clinical diagnosis will be stressed, and characteristics of these diseases in children will be reviewed briefly. Rocky Mountain spotted fever is usually contracted during the spring or summer through the bite of an infected tick although infection also may be acquired by dermal contact with tissues of a crushed or improperly removed tick. The wood tick, Dermacentor andersoni, the dog tick, D. variabilis, and the lone-star tick, Amblyomma americanum, which are found, respectively, in the western, eastern, and southern United States are responsible for transmitting the organism to man. Natural infection with Rickettsia rickettsii in these species is maintained by transovarial passage of the agent and by the feeding of immature stages on infected small mammals. Environmental factors such as rainfall, temperature, food supply of small mammals, and prevalence of predators indirectly affect the abundance of ticks.

Infections due to Rickettsia and Related Organisms

2017 ◽  
Author(s):  
Lucas S Blanton
Keyword(s):  
Q Fever ◽  
Spotted Fever ◽  
Dynamic Change ◽  
Clinical Manifestations ◽  
Rocky Mountain ◽  
Febrile Illness ◽  
American Southwest ◽  
Diagnostic Methods ◽  
Spotted Fever Group ◽  
Rocky Mountain Spotted Fever

Infections caused by organisms of the genus Rickettsia, Orientia, Ehrlichia, Anaplasma, and Coxiella occur throughout the world and are important, yet often overlooked, causes of febrile illness. They are transmitted by ticks, lice, mites, fleas, and, in the case of Coxiella, infected aerosols. Some are considered emerging and reemerging infectious diseases, as exemplified by the emergence of Rocky Mountain spotted fever in the American Southwest and Mexico; the reemergence of murine typhus in parts of Texas; and the discovery of new pathogens, such as Ehrlichia muris–like agent. Manifestations are usually of an acute undifferentiated febrile illness, with associated headache, malaise, myalgias, and varying frequency of rash. Since confirmation of diagnosis is often retrospective, requiring the dynamic change in antibody titers from acute and convalescent phase sera, clinical recognition for empirical treatment is imperative. Indeed, timely treatment is effective at abating symptoms and preventing complications. This review discusses important aspects of the epidemiology, clinical manifestations, diagnostic methods, and treatment of infections caused by Rickettsia and related organisms.  This review contains 5 figures, 9 tables, and 50 references. Key words: anaplasmosis, ehrlichiosis, Q fever, Rocky Mountain spotted fever, scrub typhus, spotted fever group rickettsioses, typhus group rickettsioses

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