We investigated the appearance and evolution of immunoglobulin M (IgM) and IgG antibodies to Borrelia burgdorferi in 46 patients with culture-proven erythema migrans (EM). All patients received antimicrobial treatment and were prospectively evaluated for up to 1 year. A total of 257 serially collected serum samples were tested by commercial IgG-IgM enzyme-linked immunosorbent assay and separate IgM and IgG immunoblots (IBs). At the baseline, 33% of the patients had a positive ELISA result and 43% of the patients had a positive IgM IB result by using the criteria of the Centers for Disease Control and Prevention-Association of State and Territorial Public Health Laboratory Directors for the interpretation of IB results. Positive serology at the baseline and the rate of seroconversion correlated directly with disease duration and/or evidence of dissemination prior to treatment. At days 8 to 14 after the baseline, 91% of patients had a positive ELISA result and/or IgM IB result. Peak IgM antibody levels were seen at this time in patients with localized or disseminated disease. The most frequent IgM bands at the baseline and the peak were of 24 kDa (OspC), 41 kDa, and 37 kDa. Although 89% of the patients developed IgG antibodies as determined at a follow-up examination, only 22% were positive by the IgG IB criteria of the Centers for Disease Control and Prevention-Association of State and Territorial Public Health Laboratory Directors. The persistence of antibodies was directly related to disease duration and/or dissemination prior to treatment. Since IgM antibodies to the 24-and 41-kDa antigens remained detectable for long periods, 38% of IgM IBs were still positive at 1 year postbaseline. IgM to antigens of 39, 58, 60, 66, or 93 kDa, conversely, were most often seen in sera obtained within 1 month postbaseline. Their presence may be of assistance in confirming a recent infection with B. burgdorferi in individuals living in areas where Lyme disease is endemic.

Using a commercially available enzyme-linked immunosorbent assay (ELISA) and an immunoblot assay (IB), we tested sera from 100 patients with erythema migrans (EM) seen in 1991 at the Westchester County Medical Center Lyme Disease Diagnostic Center. Convalescent-phase sera were available from 59 patients. Fifty-five patients had EM of <7 days' duration, 31 had EM of 7 to 14 days' duration, and 14 had EM of >14 days' duration. During the acute phase of infection, 35 patients had a positive ELISA result and 43 had a positive IB result by the recently published criteria of Dressler et al.

Human granulocytic ehrlichiosis (HGE) is caused by obligate intracellular bacteria in the Ehrlichia phagocytophila group. The disease ranges from subclinical to fatal. We speculated that cell-mediated immunity would be important for recovery from and potentially in the clinical manifestations of HGE; thus, serum tumor necrosis factor alpha (TNF-␣), interleukin 1␤ (IL-1␤), gamma interferon (IFN-␥), IL-10, and IL-4 concentrations were studied. IFN-␥ (1,035 ؎ 235 pg/ml [mean ؎ standard error of the mean]) and IL-10 (118 ؎ 46 pg/ ml) concentrations were elevated in acute-phase sera versus convalescent sera and normal subjects (P < 0.013 and P < 0.018, respectively). TNF-␣, IL-1␤, and IL-4 levels were not elevated. Cytokine levels in severely and mildly affected patients were not different. HGE leads to induction of IFN-␥-dominated cell-mediated immunity associated with clinical manifestations, recovery from infection, or both.Human granulocytic ehrlichiosis (HGE) is a tick-borne zoonosis caused by an obligate intracellular Ehrlichia species similar or identical to Ehrlichia equi and Ehrlichia phagocytophila (1, 3). Most infections are mild; however, on occasion severe complications, including opportunistic infections and fatalities, have been documented (14). E. phagocytophila infection of sheep and goats and E. equi infection in horses may be complicated by opportunistic infections as well (15). Except for serologic studies, immunologic function in humans with HGE has not been previously studied. Most infections by obligate intracellular bacteria require intact cell-mediated immunity for recovery from and protection against reinfection (5). To further characterize the human immune response to HGE and to ascertain if cytokine expression is associated with disease severity, we tested sera from patients during acute illness compared with those of patients during convalescence for the presence of the proinflammatory cytokines tumor necrosis factor alpha (TNF-␣) and interleukin 1␤ (IL-1␤), the TH1-associated immune cytokine gamma interferon (IFN-␥), and the TH2-associated cytokines IL-4 and IL-10.(Presented in part at the Thirteenth Sesqui-Annual Meeting of the American Society for Rickettsiology, 21 to 24 September, 1997, Champion, Pa. [abstract no. 96].) MATERIALS AND METHODSPatients. HGE was diagnosed from typical clinical manifestations plus (i) a single serum immunofluorescent antibody (IFA) titer of Ն160, (ii) a single serum IFA titer of Ն80 and morulae in peripheral blood neutrophils, (iii) seroconversion by IFA, (iv) culture recovery of the HGE agent, or (v) HGE agent DNA in acute-phase blood by PCR. Patients were considered severely affected if they were hospitalized.Sera for cytokine and serologic analyses. Acute-phase sera were obtained during active disease at the earliest interval after onset. Acute-phase sera, convalescent-phase sera obtained 10 or more days later, and sera from healthy adult subjects were stored frozen at Ϫ80°C.IFA assay for HGE serodiagnosis. A modified IFA assay was performed as previou...

Two variants of Campylobacterjejuni IN1 differing in the expression of flagella, IN1 (Fla' Mot', wild type) and IN1-NM (Fla-Mot-), were tested for their ability to establish infection in adult hamsters. Animals were challenged intracecally with 2 x 109 to 5 x 1010 CFU and monitored for evidence of infection. None of the challenged animals developed illness. There was a significant difference, however, in the ability of IN1 to infect hamsters (35 of 43) compared with that of IN1-NM (1 of 42) (P < 0.01). Additionally, eight animals challenged with IN1-NM excreted only the campylobacters of Fla' phenotype, which were shown to be identical with the parental Fla' Mot' type. Both groups of animals developed serum immunoglobulin G antibodies to outer membrane proteins of IN1 as measured by an enzyme-linked immunosorbent assay; however, only animals that excreted Fla' organisms developed antiflagellin antibodies. In vitro reversibility from Fla' to Flaoccurred with a frequency of 9.2 x 10-6 per cell per generation; however, reversion from Flato Fla' could not be detected in vitro. Further characterization of IN1-NM showed that it produced a cytoplasmic 62K flagellin subunit protein, but this protein lacked six epitopes detected in IN1 and also differed in its two-dimensional gel electrophoresis pattern. The results of these studies support the concept that an intact flagellum is necessary for intestinal infection with C. jejuni and that this model may be useful for studying the immune response to C. jejuni.Studies during the past few years have shown that the flagella of Campylobacterjejuni, a common cause of human gastrointestinal infection, may be important pathogenic determinants in helping the organism establish infection in the gastrointestinal tract. In vitro studies suggest a role for flagella in pathogenesis by means of motility (15) or attachment (14, 21), but the mechanism is not known. Few studies have been performed in animals (1,4,20,21,28) or humans (2) addressing the role of campylobacter flagella in causing infection. A few previous studies have used aflagellate variants in vivo; however, these variants have had relatively high frequencies of reversion (4) to the motile phenotype.In 1985, Humphrey et al. (9, 10) reported on a hamster model of C. jejuni infection. We developed this model in our laboratory to study the biologic function of campylobacter flagella in vivo. Contrary to the reports by Humphrey and colleagues, with identical protocols we were unable to induce diarrhea or colitis in hamsters. During the course of these experiments, however, we found significant differences in the ability of the flagellate and nonflagellate variants of C. jejuni to establish asymptomatic infection. Importantly, we used a Fla-variant with high in vitro stability to assess the importance of campylobacter flagella in infection. Additionally, infected hamsters mounted a systemic immune response to local infection with C. jejuni and, in preliminary experiments, were protected from homologous challenge. MATERIALS AND...

We used the Du Pont radioimmunoassay kit for soluble Legionella pneumophila serogroup 1 antigenuria (Du Pont Co., Wilmington, Del.) to test 422 urine samples from patients with and without Legionnaires disease (LD). The urine specimens were collected from 23 patients with culture-proven LD and from 346 patients without LD. L. pneumophila serogroup 1 was isolated from 14 patients with culture-proven LD, and other L. pneumophila serogroups or other Legionella species were isolated from 9 patients; 58 urine specimens were tested from these 23 patients. The non-LD group was composed of 75 bacteremic patients (35 gram-negative and 40 gram-positive bacteremias), 7 patients with candidemia, 48 patients with non-LD pneumonia, 90 patients with gram-negative bacteriuria (>105 CFU/mI), 23 patients with gram-positive bacteriuria (>105 CFU/ml), 14 patients with candiduria (>105 CFU/ml), and 89 outpatients with negative urine cultures. All tests were performed in duplicate, including positive and negative controls. Sample results with values .3.0 times those of the negative controls were considered positive for L. pneumophila serogroup 1 antigenuria. The average sample-to-negative ratios were 19.1 for the L. pneumophila serogroup 1 specimens, and 1.0 for both the non-serogroup 1 legionella group and the non-LD specimens. All but one of the patients who were culture positive for L. pneumophila serogroup 1 had at least one specimen positive for serogroup 1 antigenuria; none of the non-L. pneumophila serogroup 1 patients had a positive urine test. The test was highly specific (100%) and sensitive (93%) for the detection of L. pneumophila serogroup 1 antigenuria. Concentration of urine by vacuum evaporation increased test sensitivity without apparently affecting specificity.