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1.
Wien Med Wochenschr ; 165(7-8): 152-63, 2015 Apr.
Article in German | MEDLINE | ID: mdl-25448128

ABSTRACT

After description of the medical institutions and epidemiological situations of the Austro-Hungarian army in World War I the provisions against spotted fever focused on louse control are discussed. The letter specified for the army had to be adjusted for the local populations. 1915 in the k.u.k. military service in Galicia Edmund Weil and Arthur Felix cultivated Proteus strains from urine of soldiers with spotted fever. As sera of such patients agglutinated these bacteria in considerable titers the investigators developed the reliable diagnostic "Weil-Felix-Test" used still today. In the same military area and time Rudolf Weigl invented the anal infection of lice. This enabled him to harvest a great amount of louse intestines containing the spotted fever Rickettsiae in their epithelial cells. Lots with defined numbers of intestines were homogenized, sterilized and used with success as vaccine for medical staff. This sort of vaccine still was used in World War II.


Subject(s)
Microbiology/history , Military Medicine/history , Rickettsia prowazekii/immunology , Rickettsial Vaccines/history , Serologic Tests/history , Typhus, Epidemic Louse-Borne/history , Vaccination/history , World War I , Austria-Hungary , History, 20th Century , Humans , Male
2.
Article in Russian | MEDLINE | ID: mdl-26470431

ABSTRACT

Materials, that summarize data of original research and scientific literature on epidemiology and problems of persistence during epidemic typhus, whose causative agent (Rickettsia prowazekii) is reactivated in the organism of the previously ill and is manifested as Brill-Zinser disease, are presented. A retrospective analysis was carried out with the data obtained by Russian (All-Union) Centre for Rickettsioses during study of epidemiologic examination maps of 5705 typhus nidi and results of 19 463 blood sera analysis during study of immunologic structure of population in the territories of the former USSR for the period from 1970 to 1992. A decrease of epidemic typhus morbidity and an increase of the fraction of Brill-Zinser disease took place as a result of pediculosis corporis control. In separate territories specific weight of Brill-Zinser disease was 48% in 1952, up to 80% in 1969, and from 1977 all the ill were previously ill. However, during the perestroika period and afterwards, due to a reduction of economic and hygienic living conditions, appearance of refugees, the immune structure regarding typhus began to change. Due to the buildup of the population migration process and the presence of risk groups (refugees, homeless) among population of regions, where local wars are waged, the enhancement of methods of epidemic typhus and Brill-Zinser disease diagnostics and pediculosis corporis eradication is necessary. Study of R. prowazekii by molecular-genetics methods is necessary for complete understanding of its mechanism of persistence.


Subject(s)
Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne , Humans , Typhus, Epidemic Louse-Borne/epidemiology , Typhus, Epidemic Louse-Borne/immunology , Typhus, Epidemic Louse-Borne/microbiology , Typhus, Epidemic Louse-Borne/prevention & control
3.
J Exp Med ; 158(6): 2159-64, 1983 Dec 01.
Article in English | MEDLINE | ID: mdl-6417262

ABSTRACT

The effect of treating cultured mouse fibroblasts (L929 cells) with cloned mouse interferon-gamma on the growth of Rickettsia prowazekii within the fibroblasts was studied. Within 48 h after infection, rickettsiae were cleared from a substantial proportion of the initially infected cells and rickettsial growth was inhibited in those cells that remained infected, when L929 cells were treated with cloned mouse interferon-gamma both before and after infection. When L929 cells were treated with cloned mouse interferon-gamma either only before or only after infection with rickettsiae, rickettsial growth was markedly inhibited but rickettsiae were not cleared from many cells. Addition of cycloheximide to L929 cells markedly suppressed the antirickettsial activity of the interferon, and cloned mouse interferon-gamma did not induce antirickettsial activity in human foreskin fibroblasts. The antirickettsial effects of cloned mouse interferon-gamma were similar to those induced by crude mouse lymphokines prepared from concanavalin A-stimulated mouse spleen cells. Equivalent amounts (units) of cloned mouse interferon-gamma produced by Chinese hamster ovary cells or by Escherichia coli caused equivalent inhibition of rickettsial growth in mouse fibroblasts. However, at high concentrations of interferon-gamma, treatment of rickettsia-infected fibroblasts with equivalent amounts (units) of interferon-gamma, as crude mouse lymphokines or cloned mouse interferon-gamma, resulted in slightly greater inhibition of rickettsial growth by the crude lymphokines. Most of the antirickettsial activity of crude mouse lymphokines can be explained by the interferon-gamma that is present in these preparations. Interferon-gamma, by virtue of its ability to inhibit rickettsial growth and effect the clearance of rickettsia from nonprofessional phagocytes, may play a crucial role in the elimination of rickettsiae from the infected host.


Subject(s)
Fibroblasts/microbiology , Interferon-gamma/pharmacology , Rickettsia prowazekii/immunology , Animals , Cells, Cultured , Cloning, Molecular , Cycloheximide/pharmacology , Lymphokines/pharmacology , Mice
4.
J Exp Med ; 157(6): 1780-93, 1983 Jun 01.
Article in English | MEDLINE | ID: mdl-6189947

ABSTRACT

Unique features of the primary site of rickettsial replication in typhus fevers, i.e., within the endothelial cells of small blood vessels in tissues, suggest that effector mechanisms, other than those dependent on phagocytosis by activated macrophages with enhanced microbicidal properties, most likely are necessary to explain the cell-mediated immune control of intracellular rickettsial replication in these sites. Theoretically, such mechanisms might involve contact between infected endothelial cells and activated T lymphocyte subpopulations or macrophages or immunologically induced soluble factors or lymphokines. Support for the existence of at least one of these alternative effector mechanisms is presented here for Rickettsia prowazekii. Cultures of human blood leukocytes, upon immunologically specific stimulation with R. prowazekii antigen or nonspecific stimulation with the mitogen phytohemagglutinin, produce soluble factor(s) in the supernatant fluid which, in culture, have (a) an intracellular antirickettsial action on R. prowazekii-infected human endothelial cells, fibroblasts, and macrophages, and (b) a specific cytolytic action on R. prowazekii-infected, but not uninfected bystander, human fibroblasts. Neither action is demonstrable in R. prowazekii-infected chicken embryo fibroblasts. The factor(s) has no direct antimicrobial action on extracellular rickettsiae and is inactivated by heating at 56 degree C for 1 h or by acid treatment at pH 2. Expression of the antirickettsial action requires new host cell messenger transcription and protein synthesis, whereas the cytolytic action does not. The circumstances of production and action and the properties of the factor(s) responsible for the intracellular antirickettsial, and perhaps also the cytolytic action are consistent with those of immune interferon (IFN-gamma).


Subject(s)
Antigens, Bacterial/immunology , Interferons/immunology , Leukocytes/immunology , Phytohemagglutinins/pharmacology , Rickettsia prowazekii/immunology , Animals , Cell Line , Chick Embryo , Endothelium/microbiology , Fibroblasts/microbiology , Humans , Interferons/pharmacology , Macrophages/immunology , Rickettsia prowazekii/drug effects , Rickettsia prowazekii/physiology , Typhus, Epidemic Louse-Borne/immunology
5.
J Microbiol Methods ; 176: 106034, 2020 09.
Article in English | MEDLINE | ID: mdl-32805367

ABSTRACT

The authors applied a new methodological approach based not only on the study of IgM/IgG to Rickettsia prowazekii in sera, but also on the estimation of the avidity index of specific IgG. The data allowed the authors to draw new conclusions about the 1998 epidemic typhus outbreak in Russia.


Subject(s)
Antibodies, Bacterial/blood , Disease Outbreaks , Immunoglobulin G/blood , Immunoglobulin M/blood , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne , Humans , Retrospective Studies , Russia/epidemiology , Typhus, Epidemic Louse-Borne/blood , Typhus, Epidemic Louse-Borne/epidemiology , Typhus, Epidemic Louse-Borne/immunology
6.
Infect Immun ; 77(8): 3244-8, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19506016

ABSTRACT

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligately intracytoplasmic bacterium, a lifestyle that imposes significant barriers to genetic manipulation. The key to understanding how this unique bacterium evades host immunity is the mutagenesis of selected genes hypothesized to be involved in virulence. The R. prowazekii pld gene, encoding a protein with phospholipase D activity, has been associated with phagosomal escape. To demonstrate the feasibility of site-directed knockout mutagenesis of rickettsial genes and to generate a nonrevertible vaccine strain, we utilized homologous recombination to generate a pld mutant of the virulent R. prowazekii strain Madrid Evir. Using linear DNA for transformation, a double-crossover event resulted in the replacement of the rickettsial wild-type gene with a partially deleted pld gene. Linear DNA was used to prevent potentially revertible single-crossover events resulting in plasmid insertion. Southern blot and PCR analyses were used to confirm the presence of the desired mutation and to demonstrate clonality. While no phenotypic differences were observed between the mutant and wild-type strains when grown in tissue culture, the pld mutant exhibited attenuated virulence in the guinea pig model. In addition, animals immunized with the mutant strain were protected against subsequent challenge with the virulent Breinl strain, suggesting that this transformant could serve as a nonrevertible, attenuated vaccine strain. This study demonstrates the feasibility of generating site-directed rickettsial gene mutants, providing a new tool for understanding rickettsial biology and furthering advances in the prevention of epidemic typhus.


Subject(s)
Bacterial Proteins/genetics , Gene Knockout Techniques , Mutagenesis, Site-Directed , Phospholipase D/genetics , Rickettsia prowazekii/pathogenicity , Virulence Factors/genetics , Animals , Bacterial Vaccines/immunology , Body Temperature , Body Weight , Cell Line , Guinea Pigs , Macrophages/microbiology , Male , Mice , Rickettsia prowazekii/genetics , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/immunology , Typhus, Epidemic Louse-Borne/microbiology , Typhus, Epidemic Louse-Borne/prevention & control , Virulence
7.
J Vector Ecol ; 33(1): 205-7, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18697325

ABSTRACT

We tested sera from 176 homeless people in Houston for antibodies against typhus group rickettsiae (TGR). Sera from 19 homeless people were reactive to TGR antigens by ELISA and IFA. Two people had antibodies against Rickettsia prowazekii (epidemic typhus) and the remaining 17 had antibodies against Rickettsia typhi (murine typhus).


Subject(s)
Antibodies, Bacterial/blood , Ill-Housed Persons , Rickettsia prowazekii/immunology , Rickettsia typhi/immunology , Adult , Aged , Antibodies, Bacterial/immunology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Texas
8.
Mikrobiyol Bul ; 42(2): 301-13, 2008 Apr.
Article in Turkish | MEDLINE | ID: mdl-18697428

ABSTRACT

During the years of World War I, several severe typhus epidemics were seen in Erzurum and nearby cities. A total of 164 health officers, 125 of whom were physicians, struggled against the epidemic in the region but also they lost their lives due to typhus. Vaccination against typhus was one of the means of fighting the epidemic. However, there were some claims that a small group of Turkish physicians injected typhus-contaminated serum into Armenian civilians during World War I, and that this should be accepted as a form of biological warfare against Armenian civilians. The purpose of this article is to set out how, by whom, and on whom, and under what conditions the typhus vaccination was applied in order to reveal the truth in terms of the evidence found in historical documents. The typhus vaccine was prepared from blood taken from febrile patients affected by the disease. After the blood of the patients were defibrinated and inactivated at 60 degrees C for an hour, it was used. As the amount of blood needed to prepare the vaccine was so great, the amount of available vaccine was always insufficient to meet the demand. Hence, the prepared vaccine was only applied to those which had the higher risk of contracting typhus such as physicians and nurses. The vaccine prepared by The Third Army Health Commander Dr. Tevfik Salim was first applied to nine officers, five of whom were physicians, and among whom were Dr. Haydar Cemal and Dr. Salahattin on March 28, 1915 in Hasankale, Erzurum. Furthermore, the same vaccine was applied to people in the vicinity by Dr. Alaattin in Erzurum, Dr. Abdulhalim Asim in Bayburt, Dr. Izak in Sivas and Dr. Mihran in Hasankale. Ali Ihsan Sabis and Fevzi Cakmak, who were high ranking officers, were among those who volunteered to have the vaccination. The Third Army Health Commander Dr. Tevfik Salim ordered that the vaccine should not be applied without blood inactivation. Despite this order, Dr. Hamit Osman, who had a mental illness, applied the vaccination without inactivating the blood to some people. Among those were physicians of the Red Crescent Hospital together with soldiers who were nursing in the hospitals in Erzincan. Dr. Hamdi Suat inactivated the blood by leaving it at -16 degrees C for 24-48 hours, and instead of giving a single dose, he applied three-doses with 3-day-intervals, followed by a one more dose, which he called "the vaccine for absolute immunization" to the same people after 10-23 days. This "vaccine for absolute immunization" was actually typhus-contaminated blood which had not been inactivated. It should be noted that he injected himself with the same form of vaccine. In his article published in German in 1916 and in Turkish in 1917, he stated that he injected "the vaccine for absolute immunization" to some subjects 'condemned to death'. Dr. Haydar Cemal claimed, in a newspaper dated December 23, 1918, that the people reported as subjects 'condemned to death' were indeed Armenians, and that the innocent Armenians marked out for deportation were inoculated with the blood of typhus fever patients, and that he eyewitnessed all these events. As a result of his claims, the Interior Ministry demanded an immediate investigation, and at the end of that investigation it was understood that Dr. Haydar Cemal and Dr. Hamdi Suat had never worked together in Erzincan at the time Dr. Haydar Cemal claimed. All the claims were refuted by the investigating committee and nobody was charged. During a severe typhus epidemic, Turkish physicians injected the typhus vaccine for the purpose of "saving a life from the fire". The typhus vaccine was prepared using the available scientific knowledge of the time. No racial or religious discrimination against the people vaccinated had been proved. According to the sources, the claim that some Turkish physicians used the blood of patients with typhus as a means of biological warfare does not reflect the historical truth.


Subject(s)
Physician's Role/history , Rickettsia prowazekii/immunology , Rickettsial Vaccines/history , Typhus, Epidemic Louse-Borne/history , Vaccination/history , World War I , Biological Warfare/history , History, 20th Century , Humans , Turkey , Typhus, Epidemic Louse-Borne/prevention & control
9.
Clin Infect Dis ; 45 Suppl 1: S52-5, 2007 Jul 15.
Article in English | MEDLINE | ID: mdl-17582570

ABSTRACT

Because of their unique biological characteristics, such as environmental stability, small size, aerosol transmission, persistence in infected hosts, low infectious dose, and high associated morbidity and mortality, Rickettsia prowazekii and Coxiella burnetii have been weaponized. These biological attributes would make the pathogenic rickettsiae desirable bioterrorism agents. However, production of highly purified, virulent, weapon-quality rickettsiae is a daunting task that requires expertise and elaborate, state-of-the art laboratory procedures to retain rickettsial survival and virulence. Another drawback to developing rickettsial pathogens as biological weapons is their lack of direct transmission from host to host and the availability of very effective therapeutic countermeasures against these obligate intracellular bacteria.


Subject(s)
Bioterrorism , Coxiella burnetii/pathogenicity , Disaster Planning , Pediculus/microbiology , Rickettsia prowazekii/pathogenicity , Animals , Anti-Bacterial Agents/therapeutic use , Doxycycline/therapeutic use , Humans , Q Fever/prevention & control , Q Fever/transmission , Rickettsia prowazekii/drug effects , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/prevention & control , Typhus, Epidemic Louse-Borne/transmission , Virulence
10.
J Wildl Dis ; 43(4): 684-9, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17984264

ABSTRACT

Epidemic typhus, caused by Rickettsia prowazekii, is maintained in a southern flying squirrel (Glaucomys volans) sylvatic cycle in the southeastern United States. The northern flying squirrel (Glaucomys sabrinus) has not been previously associated with R. prowazekii transmission. A second rickettsial pathogen, Anaplasma phagocytophilum, infects dusky-footed woodrats (Neotoma fuscipes) and tree squirrels in northern California. Because northern flying squirrels or their ectoparasites have not been tested for these rickettsial pathogens, serology and polymerase chain reaction (PCR) were used to test 24 northern flying squirrels for R. prowazekii and A. phagocytophilum infection or antibodies. Although there was no evidence of exposure to R. prowazekii, we provide molecular evidence of A. phagocytophilum infection in one flying squirrel; two flying squirrels also were seropositive for this pathogen. Fleas and ticks removed from the squirrels included Ceratophyllus ciliatus mononis, Opisodasys vesperalis, Ixodes hearlei, Ixodes pacificus, and Dermacentor paramapertus.


Subject(s)
Anaplasma phagocytophilum/immunology , Ehrlichiosis/veterinary , Rickettsia prowazekii/immunology , Rodent Diseases/epidemiology , Sciuridae/microbiology , Sigmodontinae/microbiology , Typhus, Epidemic Louse-Borne/veterinary , Animals , Antibodies, Bacterial/blood , Arthropod Vectors/virology , California , Disease Reservoirs/veterinary , Ectoparasitic Infestations/epidemiology , Ectoparasitic Infestations/microbiology , Ectoparasitic Infestations/veterinary , Ehrlichiosis/epidemiology , Ehrlichiosis/transmission , Female , Male , Rodent Diseases/transmission , Sciuridae/parasitology , Seroepidemiologic Studies , Sigmodontinae/parasitology , Siphonaptera/microbiology , Ticks/virology , Typhus, Epidemic Louse-Borne/epidemiology , Typhus, Epidemic Louse-Borne/transmission
11.
Ann N Y Acad Sci ; 1063: 327-32, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16481535

ABSTRACT

The state of Nuevo Leon, Mexico has had outbreaks of typhus group rickettsiosis, most recently recognized in 1997. Evaluation of the sera of 345 patients with a dengue-like illness revealed that 25.5% had antibodies reactive with typhus group rickettsiae and 16% had antibodies to Rickettsia parkeri. Rickettsiae were detected by PCR and shell-vial isolations in the field-collected Amblyomma ticks. Molecular characterization by DNA sequence analysis of the gltA, ompB, and 17-kDa gene identified the organisms to be R. prowazekii.


Subject(s)
Rickettsia prowazekii/immunology , Ticks/microbiology , Typhus, Endemic Flea-Borne/diagnosis , Typhus, Epidemic Louse-Borne/diagnosis , Animals , Humans , Immunoglobulin G/blood , Mexico/epidemiology , Rickettsia prowazekii/isolation & purification , Rickettsia typhi/immunology , Rickettsia typhi/isolation & purification , Ticks/genetics , Typhus, Endemic Flea-Borne/epidemiology , Typhus, Endemic Flea-Borne/transmission , Typhus, Epidemic Louse-Borne/epidemiology , Typhus, Epidemic Louse-Borne/transmission
12.
Mol Immunol ; 29(1): 95-105, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1370573

ABSTRACT

The 120 kDa surface protein antigens (SPAs) of typhus rickettsiae lie external to the outer membrane in regular arrays and chemically resemble the S-layer proteins of other bacteria. These proteins elicit protective immune responses against the rickettsiae. In order to study the immunochemistry of these proteins, purified SPAs from Rickettsia typhi and Rickettsia prowazekii were fragmented with CNBr. The fragments were separated by SDS-PAGE and were recovered on PVDF membrane following electroblotting. The origin of eight major fragments from R. prowazekii and seven major fragments from R. typhi was determined by automated N-terminal amino acid sequencing and by comparison with the DNA sequence encoding R. prowazekii SPA. The cleavage patterns and protein sequences of the two proteins differed significantly. CNBr fragments corresponding to the C-terminus (amino acid 1372-1612 of the deduced sequence from encoding gene spaP) were not present in both SPAs. This suggests that the corresponding C-terminal region was not synthesized or was removed during SPA translocation to the cell surface. Modified amino acids were detected in each protein. Eighteen monoclonal antibodies selected for varied reactivity with both native and denatured SPA proteins could be classified into eight different types based on western blot analysis of the CNBr fragments. Six of the monoclonal antibody types reacted predominantly with a single region of the SPAs. Two types of antibodies bound to several CNBr fragments which contained both limited sequence similarity and modified amino acids either of which might account for the multisite binding of these antibodies.


Subject(s)
Antibodies, Bacterial/immunology , Antibodies, Monoclonal/immunology , Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Membrane Glycoproteins , Rickettsia prowazekii/immunology , Rickettsia typhi/immunology , Amino Acid Sequence , Antibody Specificity , Antigens, Bacterial/chemistry , Bacterial Proteins/chemistry , Cyanogen Bromide , Epitopes , Molecular Sequence Data , Molecular Weight , Peptide Fragments/immunology
13.
Ann N Y Acad Sci ; 590: 256-65, 1990.
Article in English | MEDLINE | ID: mdl-2116104

ABSTRACT

Epidemiologic investigations were recently conducted on four cases which were reported in New York State in 1986 and 1987, three of which were within one family. These included hospital chart reviews, case or family interviews, animal trappings, and ectoparasite surveys. Serologic tests and immunoblots were performed on blood samples obtained from these patients. All four patients had acute febrile illnesses; two required hospitalization and one died. Microimmunofluorescence test results using Rickettsia typhi and R. prowazekii antigens showed a greater than or equal to 4-fold increase in titer with paired sera from three patients. The remaining patient had a single serum titer of 4096 with both antigens. In addition, sera from all patients reacted with R. typhi in the immunoblot test and, from the three patients for whom sera were available, also with R. prowazekii. Results suggest that the four patients were exposed to the typhus-group rickettsiae or to an organism which shares a common epitope(s).


Subject(s)
Typhus, Epidemic Louse-Borne/diagnosis , Adult , Antibodies, Bacterial/analysis , Child , Female , Humans , Male , New York , Rickettsia prowazekii/immunology , Rickettsia rickettsii/immunology , Rickettsia typhi/immunology
14.
Ann N Y Acad Sci ; 990: 757-64, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12860719

ABSTRACT

Rickettsia prowazekii, the etiologic agent of louse-borne typhus, is listed as a category B agent under the select agent list of the United States Centers for Disease Control and Prevention. R. prowazekii was placed on the select agent list due to its potential to cause epidemic, high mortality in untreated and/or misdiagnosed cases, and ease of spread in vulnerable populations. Historically, R. prowazekii vaccines using crude antigen and/or inactivated rickettsia were partially protective but have been accompanied with undesirable toxic reactions and difficulties in standardization. The availability of the genome sequence of R. prowazekii allowed us to select genes that encode proteins with potential in immuno-protection against this human pathogen. We successfully PCR-amplified a group of genes involved in invasion (invA), cell division (fts), protein secretion (sec gene family), and virulence (ompA and ompB, virB gene family, cap and tlyA and tlyC). The generated PCR products were cloned into the Gateway cloning system and the cloned products will be introduced into Vical VR 1020-DV and VR 1012-DV DNA vaccine plasmids. Twenty-four target genes from R. prowazekii have been PCR amplified, of which fifteen have been introduced into the pENTR/SD/D-TOPO entry cloning vector.


Subject(s)
Bacterial Vaccines , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/immunology , Typhus, Epidemic Louse-Borne/prevention & control , Vaccines, DNA , Animals , Base Sequence , Cloning, Molecular , DNA Primers , Humans , Phthiraptera/microbiology , Plasmids , Polymerase Chain Reaction/methods , Rickettsia prowazekii/genetics
15.
Ann N Y Acad Sci ; 266: 6-24, 1975.
Article in English | MEDLINE | ID: mdl-829475

ABSTRACT

Evidence is presented to indicate that proteolytic and perhaps other enzymes of the louse midgut, essential to the nutrition of the louse, perform molecular dissection on the antirickettsial antibodies present in the blood of a typhus-immune host that selectively destroys, along with other functions, the portion of the antibody that determines the only known function by which antirickettsial antibodies may operate in host defense mechanisms, namely, opsonization of rickettsiae for enhanced ingestion by professional phagocytes and subsequent destruction. The epidemiologic significance of these findings is discussed in relation to the progressive destruction of cells that produce digestive enzymes of the louse midgut that occurs with progressive rickettsial infection, and the possibility of a negative feedback mechanism in transmission is introduced. Speculations that involve evolutionary concepts of both convergent and divergent varieties with respect to rickettsiae, potentially operational in a system that consists of an obligate blood-sucking arthropod vector and a vertebrate host capable of adaptive responses to both vector and rickettsial agent, are presented.


Subject(s)
Antibodies, Bacterial/metabolism , Pediculus/metabolism , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/immunology , Animals , Centrifugation, Density Gradient , Feces/immunology , Fluorescent Antibody Technique , Humans , Immunodiffusion , Immunoelectrophoresis , Immunoglobulin A/metabolism , Immunoglobulin Fab Fragments/metabolism , Immunoglobulin Fc Fragments/metabolism , Immunoglobulin G/metabolism , Immunoglobulin M/metabolism , Phagocytosis
16.
Am J Trop Med Hyg ; 29(2): 277-84, 1980 Mar.
Article in English | MEDLINE | ID: mdl-6154428

ABSTRACT

From January 1976 through January 1979 serum specimens from 1,575 individuals were received at the Center for Disease Control and tested for antibodies to rickettsiae. Of these, sera from eight persons gave serological results indicative of recent infections with epidemic typhus rickettsiae (Rickettsia prowazekii). Five of the persons were from Georgia, and one each was from Tennessee, Pennsylvania and Massachusetts. The illnesses occurred during the winter, chiefly in persons living in a rural environment. The clinical picture was compatible with louse-borne epidemic typhus. There was no apparent contact with human body or head lice, and no cases occurred in patient contacts, indicating that infection was not associated with the classic man-louse-man cycle of epidemic typhus. Two of the eight patients had contact with flying squirrels suggesting that they became infected from this known extrahuman reservoir of R. prowazekii.


Subject(s)
Disease Outbreaks/epidemiology , Typhus, Epidemic Louse-Borne/epidemiology , Adolescent , Adult , Aged , Antibodies, Bacterial/analysis , Epitopes , Female , Humans , Male , Middle Aged , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/immunology , Typhus, Epidemic Louse-Borne/transmission , United States
17.
FEMS Microbiol Lett ; 65(3): 341-4, 1991 Jul 01.
Article in English | MEDLINE | ID: mdl-1916232

ABSTRACT

Using immunoblots to analyze antigenic relationships among the pathogenic spotted fever and typhus group rickettsiae, I found that the rickettsial lipopolysaccharide (LPS) was a group-specific antigen. All the rickettsiae examined had 135-kDa and 58-kDa protein antigens. The spotted fever rickettsiae and Rickettsia canada had, in addition, 190-kDa protein antigens which were antigenic analogs of previously described protective antigens of R. conorii and R. rickettsii.


Subject(s)
Antigens, Bacterial/immunology , Rickettsia/classification , Animals , Bacterial Proteins/immunology , Blotting, Western , Cell Fractionation , Electrophoresis, Polyacrylamide Gel , Guinea Pigs , Immune Sera , Lipopolysaccharides/immunology , Rickettsia/immunology , Rickettsia Infections/microbiology , Rickettsia prowazekii/classification , Rickettsia prowazekii/immunology , Rickettsia rickettsii/classification , Rickettsia rickettsii/immunology , Rickettsia typhi/classification , Rickettsia typhi/immunology
18.
J Am Vet Med Assoc ; 207(1): 58-63, 1995 Jul 01.
Article in English | MEDLINE | ID: mdl-7601694

ABSTRACT

An unusual pattern of seroreactivity to antigens of rickettsial organisms (Rickettsia rickettsii, R rhipicephali, R montana, and R bellii), particularly to R bellii antigen, was detected in 3 dogs during a 2-month period. Thus, studies were initiated to clarify the pathogenic potential of the more distantly related rickettsial organisms (R canada and R prowazekii) in dogs. Because R bellii are nonpathogenic rickettsiae that share numerous common properties with spotted fever-group and typhus-group rickettsiae, and because closely related pathogenic relatives of R bellii have not been identified, we examined the pathogenic potential of these typhus-group rickettsiae by testing stored serum samples, by attempting rickettsial isolation from febrile dogs, and by experimentally inoculating dogs with R canada and R prowazekii. Evaluation of results of a serosurvey of acute and convalescent serum samples from 80 dogs in which Rocky Mountain spotted fever had been considered as a differential diagnosis, but seroconversion to R rickettsii had not been documented, identified 1 dog with a fourfold increase in antibody titer to R rhipicephali and 3 dogs with fourfold increases in antibody titer to 1 or more antigens of typhus-group rickettsial organisms. A study of 15 dogs that were febrile during summer months failed to identify serologic or tissue culture evidence of typhus-group rickettsial infection or typhus-group rickettsemia, but did result in isolation of R rickettsii and Ehrlichia canis, respectively, from 1 dog each. In our final study, after experimentally inoculating 6 dogs with R canada and R prowazekii, all dogs seroconverted to the respective rickettsiae, but rickettsemia or clinical and hematologic evidence of disease was not observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Dog Diseases/microbiology , Rickettsia Infections/veterinary , Rickettsia prowazekii/pathogenicity , Rickettsia/pathogenicity , Animals , Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Cell Line , Chlorocebus aethiops , Dogs , Fluorescent Antibody Technique/veterinary , Random Allocation , Reproducibility of Results , Rickettsia/immunology , Rickettsia/isolation & purification , Rickettsia Infections/microbiology , Rickettsia prowazekii/immunology , Rickettsia prowazekii/isolation & purification , Vero Cells
19.
Acta Virol ; 25(3): 150-4, 1981 May.
Article in English | MEDLINE | ID: mdl-6115563

ABSTRACT

The function of peritoneal macrophages from Rickettsia prowazeki-infected guinea pigs at various intervals of postinfection immunity was studied. The activity of macrophages in immunized animals was higher than in non-immunized ones; it was the highest in the period of the highest level of immunity and high levels of complement-fixing antibodies.


Subject(s)
Macrophages/immunology , Rickettsia prowazekii/immunology , Typhus, Epidemic Louse-Borne/immunology , Animals , Antibodies, Bacterial/analysis , Ascitic Fluid/cytology , Cells, Cultured , Chick Embryo , Complement Fixation Tests , Guinea Pigs , Immune Sera , Phagocytosis
20.
Acta Virol ; 26(5): 390-4, 1982 Sep.
Article in English | MEDLINE | ID: mdl-6128907

ABSTRACT

The features of intracellular development of the virulent Breinl strain and 3 vaccine E strains of Rickettsia prowazeki have been followed in continuous FL, McCoy, and B cell cultures at temperatures of 30, 35, 37, 38.5 and 40 degrees C. The virulent Breinl strain multiplied well at these temperatures in McCoy and B cells but in had been gradually lost when cultured at 40 degrees C in FL cells. In contrast to the virulent Breinl strain the vaccine E strains have lost their capacity of long term reproduction at 38.5 degrees C. At 40 degrees C the E strains did not multiply in and had been eliminated from the McCoy and B cells; thus the vaccine E strains revealed a ts-phenotype and, accordingly, it was found to represent a ts-mutant.


Subject(s)
Rickettsia prowazekii/growth & development , Rickettsial Vaccines/analysis , Vaccines/analysis , Animals , Cell Line , Chick Embryo , Rickettsia prowazekii/immunology , Rickettsia prowazekii/pathogenicity , Temperature , Time Factors
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