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D H Persing

Publications and source records attributed to D H Persing.

At least 163 records · Page 9Linked to original sources
PubMed1993

Chronic Lyme borreliosis in the laboratory mouse.

C3H/HeJ mice were inoculated intraperitoneally with 10(7) uncloned Borrelia burgdorferi at 4 weeks of age and examined on days 30, 90, 180, and 360. Spirochetes were isolated from multiple tissues at all intervals. Joint and heart disease were present in all mice at 30 days and resolved after 90 days. At 180 and 360 days, some mice had mild recurrent joint and heart disease, and most had peripheral segmental periarteritis. The protein electrophoretic migration of 360-day isolates differed from the original inoculum. The experiment was repeated with C3H/HeN and BALB/cByJ mice inoculated intradermally with 10(4) cloned B. burgdorferi. Characterization of infection and disease at 180 and 360 days were similar to those of the first experiment, but spirochetal proteins of isolates from both intervals displayed no protein variation in electrophoretic mobilities. Spirochetes isolated at 360 days were fully pathogenic in naive mice. Sera from infected mice showed an initial immunoglobulin M response, followed by a sustained immunoglobulin G response, involving IgG1, IgG2a, IgG2b and IgG3, with expanding reactivity against multiple antigens over time. These results indicate that immunocompetent mice sustain persistent infections and develop early acute joint and heart lesions that resolve and then recur intermittently.

Animals↗
PubMed1992

A controlled trial of antimicrobial prophylaxis for Lyme disease after deer-tick bites.

BACKGROUND: Borrelia burgdorferi, which causes Lyme disease, is transmitted by deer ticks (lxodes dammini) in the northeastern and midwestern United States. Although deer-tick bites are common in areas in which the disease is endemic, there is uncertainty about how to manage the care of persons who are bitten. METHODS: To assess the risk of infection with B. burgdorferi and the efficacy of prophylactic antimicrobial treatment after a deer-tick bite, we conducted a double-blind, placebo-controlled trial in an area of southeastern Connecticut in which Lyme disease is endemic. Children and adults who had been bitten by deer ticks were randomly assigned to receive either amoxicillin or placebo for 10 days. Subjects were followed for one year for clinical manifestations of Lyme disease. Serum samples obtained at enrollment and six weeks and three months later were tested for antibodies against B. burgdorferi. RESULTS: Of the 387 subjects, 205 (53 percent) were assigned to receive amoxicillin and 182 (47 percent) to receive placebo. Of 344 deer ticks submitted and analyzed by the polymerase chain reaction, 15 percent were infected with B. burgdorferi. Erythema migrans developed in two subjects, both of whom had received placebo. There were no asymptomatic seroconversions and no late manifestations of Lyme disease. The risk of infection with B. burgdorferi in the placebo-treated subjects was 1.2 percent (95 percent confidence interval, 0.1 to 4.1 percent), which was not significantly different (P = 0.22) from the risk in the amoxicillin-treated subjects (0 percent; 95 percent confidence interval, 0 to 1.5 percent). CONCLUSIONS: Even in an area in which Lyme disease is endemic, the risk of infection with B. burgdorferi after a recognized deer-tick bite is so low that prophylactic antimicrobial treatment is not routinely indicated.

Adult↗
PubMed1992

Borrelia burgdorferi strain 25015: characterization of outer surface protein A and vaccination against infection.

Mice vaccinated with outer surface protein A (OspA) from Borrelia burgdorferi strain N40 are protected from challenge with an intradermal syringe inoculum of B. burgdorferi strains N40, B31, and CD16. Vaccination experiments were done to determine if protection extended to strains 297 and 25015. We now show that OspA-N40 immunized mice are protected against challenge with strain 297, isolated from the cerebrospinal fluid of a patient with neuroborreliosis, but not against challenge with strain 25015, isolated from a tick in Millbrook, NY. The OspA gene from strain 25015 was therefore cloned and sequenced. The deduced OspA-25015 protein sequence differs from OspA-N40 at 40 of 273 amino acids. Furthermore, mice vaccinated with rOspA-25015 are protected from challenge with strain 25015 but not against strain N40. The results extend the usefulness of OspA as a vaccine candidate, but indicate that OspA can vary among strains of B. burgdorferi and that vaccination of mice with OspA-N40 does not protect against intradermal challenge with an inoculum of 10(4) strain 25015 spirochetes.

Amino Acid Sequence↗
PubMed1992

Chemiluminescent universal probe for bacterial ribotyping.

We describe a novel procedure for direct covalent coupling of horseradish peroxidase to rRNA and ribotyping by using enhanced chemiluminescence. Compared with their 32P-end-labeled counterparts, chemiluminescent rRNA probes are stable and easy to synthesize and provide results as good as or superior to those obtained with isotopic labeling. Direct chemiluminescent labeling of Escherichia coli rRNA produces a sensitive, universal probe suitable for clinical laboratory use in the investigation of nosocomial outbreaks.

Bacterial Typing Techniques↗
PubMed1992

Ribosomal DNA probe for differentiation of Babesia microti and B. gibsoni isolates.

The objective of this study was to determine whether different isolates of Babesia microti could be distinguished from morphologically similar isolates of B. gibsoni by using a ribosomal DNA (rDNA) probe. A Babesia-specific rDNA probe was obtained by polymerase chain reaction amplification of sequences from B. microti DNA using universal primers directed against highly conserved portions of the eukaryotic 16S-like rRNA gene. The chemiluminescent rDNA probe hybridized to Southern blots of restriction endonuclease-digested DNA preparations of different isolates of B. gibsoni from infected dogs and B. microti from infected humans and white-footed mice. Restriction fragment length polymorphisms served to differentiate these species. Although the hybridization patterns seen with DNAs from six B. microti isolates did not vary, those of the five B. gibsoni isolates did indicate genotypic variation. We concluded that isolates of B. microti and B. gibsoni can be differentiated on the basis of restriction fragment length polymorphism detected with a chemiluminescent rDNA probe.

Animals↗
PubMed1992

Detection of Babesia microti by polymerase chain reaction.

Human babesiosis, which is caused by infection with the intraerythrocytic malarialike protozoan Babesia microti, has recently been diagnosed with increasing frequency in residents of New England. Diagnosis is difficult because of the small size of the parasite and the sparse parasitemia that is characteristic of most infections with this pathogen. We generated B. microti-specific DNA sequence information by universal primer amplification of a portion of the eukaryotic 16S-like gene; this was followed by direct DNA sequence analysis. Specific primers were synthesized on the basis of this sequence information for use in the polymerase chain reaction (PCR). The PCR-based system demonstrates a strong bias for detection of B. microti as opposed to Babesia gibsoni and does not amplify vertebrate DNA. The analytical sensitivity of the system is approximately three merozoites. Blood specimens from 12 patients with clinically diagnosed and parasitologically confirmed babesiosis from Nantucket Island, Mass., were PCR positive in a blinded test of this procedure. Thus, DNA amplification may provide an adjunct to conventional methods for the diagnosis of human babesiosis and may provide a new means of monitoring therapy or enhancing epidemiological surveillance for this emerging pathogen.

Animals↗
PubMed1992

Carditis in Lyme disease susceptible and resistant strains of laboratory mice infected with Borrelia burgdorferi.

The clinical and pathologic evolution of cardiac Lyme disease was evaluated in four-week-old susceptible C3H/He (C3H) and resistant C57Bl/6 (B6) mice on days 3, 6, 10, 15, 30, 60, and 90 after intradermal inoculation with Borrelia burgdorferi strain N40. Culture, DNA polymerase chain reaction, in situ nucleic acid hybridization, immunoperoxidase histochemical analysis, and silver stain were used to detect spirochetes. Spirochetes were first detected by culture on day 6 in two of four C3H mice. The hearts of all mice of both genotypes were culture positive by day 10 and infection persisted through day 90. The spirochetes had a predilection for connective tissue in the heart base, especially around the aorta, epicardium of the upper ventricles and atria, myocardial interstitium, and endocardium. Carditis was first detectable on day 10, reaching a maximum severity on day 15, then resolved, except for persistence of periaortic lymphoplasmacytic infiltrates through day 90 in C3H mice and through day 60 in B6 mice. The C3H mice developed more severe disease than the B6 mice, and this was associated with the earlier appearance, greater numbers, and later clearance of spirochetes in C3H mice. Electrocardiographs of infected and control mice revealed bradycardia and tachycardia in many C3H mice, but in very few B6 mice. Serum creatinine phosphokinase levels did not become elevated at any interval.

Animals↗
PubMed1991

Kinetics of Borrelia burgdorferi dissemination and evolution of disease after intradermal inoculation of mice.

Borrelia burgdorferi dissemination to selected target organs was examined on days 1, 2, 3, 4, 7, 10, 15, 21, and 30 after intradermal inoculation of 4-week-old C3H mice. Infection was determined by culture (blood, spleen, kidney, ear punch); polymerase chain reaction (PCR) for outer surface protein A (OSP A) DNA (ear punch); histology and spirochete histochemistry (spleen, kidney, skin, heart, joints); and OSP A DNA in situ hybridization (joints, heart). Blood or spleen of most mice were culture positive by day 3 and ear punch by day 10. Polymerase chain reaction performed on ear punches was also positive by day 10. Inflammation of joints and tendons began on days 4 through 7 and heart on days 7 through 10, which coincided with colonization of tissues with spirochetes. Spirochetes were multifocal in distribution, with a predilection for collagenous connective tissue of joints, heart, arteries, nerves, muscle, skin, and other tissues. Relative numbers of spirochetes peaked at 15 days, then decreased by 21 days. Gamma M immunoglobulin (IgM) antibody was detectable on immunoblots as early as day 4, with subsequent declining reactivity, and IgG antibody was detectable by day 7, with expanding reactivity to multiple antigens through day 30.

Animals↗
PubMed1990

Detection of Borrelia burgdorferi DNA in museum specimens of Ixodes dammini ticks.

In order to investigate the potential for Borrelia burgdorferi infection before the recognition of Lyme disease as a clinical entity, the polymerase chain reaction (PCR) was used to examine museum specimens of Ixodes dammini (deer ticks) for the presence of spirochete-specific DNA sequences. One hundred and thirty-six archival tick specimens were obtained representing various continental U.S. locations; DNA sequences characteristic of modern day isolates of B. burgdorferi were detected in 13 1940s specimens from Montauk Point and Hither Hills, Long Island, New York. Five archival specimens of Dermacentor variabilis (dog tick) from the same collection and 118 Ixodes specimens from other endemic and nonendemic sites were negative. These data suggest that the appearance of the Lyme disease spirochete in suitable arthropod vectors preceded, by at least a generation, the formal recognition of this disease as a clinical entity in the United States.

Animals↗
PubMed1990

Detection of Borrelia burgdorferi infection in Ixodes dammini ticks with the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to amplify DNA sequences of the etiologic agent of Lyme disease, Borrelia burgdorferi, and was applied to the detection of the spirochete in its tick vector. The target for PCR amplification was the OSP-A gene of strain B31; analysis of isolates from different geographical areas indicated that this gene could be used to identify most North American isolates. These methods were extended to the analysis of colony-derived and field-collected Ixodes dammini. OSP-A-specific sequences were identified in 15 of 15 colony-derived nymphal ticks that had fed previously on an infected animal; no such amplification products were detected in 8 control ticks. Segregated midgut tissues of field-collected adult and nymphal ticks from Nantucket Island, Mass., and the Crane Reserve, Ipswich, Mass., were examined by both direct fluorescent-antibody (DFA) staining and PCR. The DFA technique identified 16 infected ticks of 30 paired specimens; 15 of these specimens were positive by PCR. One specimen was positive by PCR that was DFA negative. Both live whole ticks and desiccated dead specimens were suitable for this analysis. Because only five ticks are suitable for DFA analysis, the use of PCR may extend the range of specimens that can be analyzed for the presence of the Lyme spirochete.

Animals↗
PubMed1987

The preS1 protein of hepatitis B virus is acylated at its amino terminus with myristic acid.

The preS/S coding region of hepatitis B virus encodes two polypeptides (preS1 and preS2) that are larger in size but less abundant than the major viral surface antigen (S) protein. Unlike the preS2 and S proteins, the preS1 protein is preferentially localized on circulating virus particles but is not efficiently secreted from mammalian cells in culture. To search for differences in protein processing that might relate to these properties, we determined whether any of the hepatitis B virus surface proteins are acylated with long-chain fatty acids. Transfected COS cells expressing all three proteins were incubated with 3H-palmitate or 3H-myristate, and the cell extracts were examined by immunoprecipitation. While none of these proteins was labeled with 3H-palmitate, the preS1 protein but not the preS2 or S protein incorporated 3H-myristate via a hydroxylamine-resistant amide linkage. Comparison of the N-terminal amino acid sequences of hepadnaviral preS1 proteins with those of known myristylated proteins suggests that this unusual modification may be a common feature of all hepadnaviral preS1 proteins.

Acylation↗
PubMed1986

Inhibition of secretion of hepatitis B surface antigen by a related presurface polypeptide.

The presurface (preS) proteins of hepatitis B virus are structural components of the viral envelope that may play important roles in virion assembly and infectivity. They are specified by a large open reading frame that includes the coding region for the major surface (S) protein in its 3' half. Translation of the preS proteins initiates upstream from the S region, giving rise to proteins that are composed of the S domain and an additional 163 (preS1) or 55 (preS2) amino acids. Little is known about the biosynthesis and assembly of these proteins. The expression of the S and preS1 proteins was examined by transfecting cultured mammalian cells with viral DNA and injecting synthetic messenger RNA's into Xenopus oocytes. In contrast to the proteins encoded by the S region, the preS1 proteins are not detectably secreted into the culture medium. Furthermore, when the S and preS1 proteins are synthesized together, secretion of the S proteins is specifically and strongly inhibited. The results suggest a unique molecular interaction during secretion of the S and preS proteins that may be important for virus assembly.

Animals↗
PubMed1986

Antibodies to pre-S and X determinants arise during natural infection with ground squirrel hepatitis virus.

The DNA sequence of the ground squirrel hepatitis virus (GSHV) genome predicts the existence of several proteins in addition to the major surface (S) and core antigens. These include the pre-S1 and pre-S2 proteins, initiated at sites within the open reading frame preceding and continuous with the coding region for the S gene product, and the X protein, the putative product of an independent reading frame. Using an antibody directed against a peptide predicted by codons 130 to 143 of the pre-S1 reading frame, we identified a 43-kilodalton product of the pre-S1 coding region in preparations of GSHV surface antigen purified from the sera of infected animals. In addition, by immunoprecipitation of S- and pre-S-specific in vitro translation products with ground squirrel sera obtained after GSHV infection, we determined that antibodies arise to both S and pre-S determinants. The antibody response to pre-S includes, in some cases, reactivity to pre-S1-specific domains and is not always associated with an anti-S response. Similarly, by production of the viral X gene product in vitro followed by immunoprecipitation with ground squirrel sera, we showed that antibodies to this viral gene product also arise during infection, indicating that X antigenic determinants are synthesized during viral infection and are recognized by the host immune system.

Animals↗
PubMed1985

A frameshift mutation in the pre-S region of the human hepatitis B virus genome allows production of surface antigen particles but eliminates binding to polymerized albumin.

The coding region for the major polypeptide (p24S) of hepatitis B surface antigen (HBsAg) is preceded by an in-phase open reading frame termed pre-S. The coding potential of the pre-S region was examined in mouse L cells transformed with cloned hepatitis B virus DNA. Such cells produce three HBsAg-related polypeptides of Mr 24,000, 27,000, and 35,000 organized into complex particles of 22 nm diameter. These HBsAg particles bind to polymerized human albumin, but not to polyalbumins of several other species. In contrast, cells transformed with hepatitis B virus DNA bearing a frameshift mutation near the 3' end of the pre-S region secrete immunoreactive HBsAg particles containing only the 24,000 and 27,000 Mr species. These mutant particles, which lack the 35,000 Mr species, are unable to bind polymerized human albumin. These studies indicate that the pre-S region encodes the 35,000 Mr species, that this product accounts for the known polyalbumin-binding activity of HBsAg but is not required for assembly and secretion of HBsAg 22-nm particles, and that the major polypeptide of HBsAg is not derived primarily by cleavage of larger precursors encoded by the pre-S region.

DNA, Viral↗