Biomedical subjects

L A Magnarelli

Publications and source records attributed to L A Magnarelli.

At least 55 records · Page 3Linked to original sources

PubMed1995

Borrelia burgdorferi in an urban environment: white-tailed deer with infected ticks and antibodies.

Ticks and blood samples were collected from white-tailed deer (Odocoileus virginianus) in forests located in an insular, urban area of Bridgeport, Conn., and in rural south central Connecticut during 1992 and 1993. Immature and adult Ixodes scapularis ticks were tested for Borrelia burgdorferi, the etiologic agent of Lyme borreliosis, by indirect fluorescent-antibody staining methods. Deer sera were analyzed for antibodies to this bacterium by an enzyme-linked immunosorbent assay. Infected ticks parasitized deer in Bridgeport from May through December; the prevalence of infection varied from 1.1% of 93 larvae to 28.1% of 114 adult females. The percentages of infected males (10.5% of 380 ticks) and females (13.7% of 328 ticks) were relatively lower in south central Connecticut. In antibody tests, the prevalence of seropositive specimens collected in Bridgeport (61% of 146 serum specimens) was more than twofold greater than that of specimens obtained in south central Connecticut (26.7% of 116 serum specimens). Foci for Lyme borreliosis can occur in forested, urban settings as well as in rural areas if there are ticks, rodents, birds, and large mammals present. Human exposure to ticks in such sites should be considered as a possible source of B. burgdorferi infection.

Animals↗

PubMed1995

Analyses of mammalian sera in enzyme-linked immunosorbent assays with different strains of Borrelia burgdorferi sensu lato.

Blood samples were collected from cottontail rabbits (Sylvilagus floridanus), raccoons (Procyon lotor), white-footed mice (Peromyscus leucopus), and white-tailed deer (Odocoileus virginianus) between 1977 and 1991 in southern Connecticut and New York State (USA) and were tested for antibodies against eight strains of Borrelia burgdorferi sensu lato in enzyme-linked immunosorbent assays. Among these spirochetes were six strains of B. burgdorferi sensu stricto, one strain of B. garinii (=IP90) and a strain (IPF) in group VS461. Sera from each study group reacted positively to all strains having origins in North America and Eurasia. Assay sensitivities normally ranged between 85% and 100% for all study groups. The lowest sensitivity (66%) was noted when mouse sera were tested with B. garinii, an isolate from Ixodes persulcatus in the former Soviet Union. Differences in serum reactivity to various strains were noted for all study groups, but because of multiple shared antigens among the closely related spirochetes tested, the selection of a particular North American strain of B. burgdorferi sensu stricto did not appear to be a critical factor for optimal assay performance. Locally obtained strains of this bacterium are preferred as coating antigens for serologic testing because of their availability.

Animals↗

PubMed1995

Reactivity of white-footed mouse and raccoon sera to whole cell and recombinant antigens of Borrelia burgdorferi.

Serum samples were collected from white-footed mice (Peromyscus leucopus) and raccoons (Procyon lotor) during 1983, 1984, and 1990 through 1993 in Connecticut (USA) and were tested in enzyme-linked immunosorbent assays (ELISA) against whole cell Borrelia burgdorferi sensu stricto (strain 2591) and the following recombinant antigens of this spirochete: p41-G (an immunogenic epitope of flagellin), outer surface protein (OSP)A, and OSPB. Antibodies were most frequently detected when whole cell antigen was used in the analyses. Reactivity to highly specific recombinant antigens also occurred and was particularly helpful in verifying B. burgdorferi infection. Geometric mean antibody titers for assays with whole cell antigen ranged from 453 to 2,363 and were at least two-fold higher than geometric means calculated for tests with recombinant antigens, which ranged from 226 to 640. With greater sensitivity, an ELISA with whole cell antigen is preferred for determining presence of antibody in sites enzootic for Lyme borreliosis. However, use of highly specific recombinant antigens, particularly OSPA and OSPB, in an ELISA can provide supportive information in ecological studies of this disease.

Animals↗

PubMed1994

Detection of Borrelia burgdorferi in urine of Peromyscus leucopus by inhibition enzyme-linked immunosorbent assay.

An inhibition enzyme-linked immunosorbent assay was developed to detect Borrelia burgdorferi, the etiologic agent of Lyme borreliosis, in urine from white-footed mice (Peromyscus leucopus). Of the 87 urine specimens tested from 87 mice collected in widely separated tick-infested sites in Connecticut, 57 (65.5%) contained detectable concentrations of spirochetal antigens. Forty-seven (62.7%) of 75 serum samples analyzed contained antibodies to B. burgdorferi. In culture work with tissues from bladders, kidneys, spleens, or ears, 50 of 87 mice (57.5%) were infected with B. burgdorferi. Thirty-eight (76%) of 50 infected mice had antigens of this spirochete in urine, while 36 (72%) individuals had infected bladders. Of those with infected bladders, 24 (66.7%) mice excreted subunits or whole cells of B. burgdorferi into urine. Successful culturing of B. burgdorferi from mouse tissues, the presence of serum antibodies to this bacterium, and detection of antigens to this spirochete in urine provide further evidence that multiple assays can be performed to verify the presence of B. burgdorferi in P. leucopus.

Animals↗

PubMed1994

Comparison of different strains of Borrelia burgdorferi sensu lato used as antigens in enzyme-linked immunosorbent assays.

Eight strains of Borrelia burgdorferi sensu lato were tested with serum samples from persons who had Lyme borreliosis or syphilis in class-specific enzyme-linked immunosorbent assays (ELISAs). Antigens of B. burgdorferi sensu stricto, of Borrelia garinii, and of Borrelia spirochetes in group VS461 were prepared from cultured bacteria isolated from ticks, a white-footed mouse (Peromyscus leucopus), or human tissues in North America, the former Soviet Union, and Japan. Nearly all of the serum specimens that contained immunoglobulins to strain 2591, a Connecticut isolate, were also positive in antibody tests with the other seven strains. In general, all eight strains reacted similarly and were suitable as coating antigens in class-specific ELISAs. Assay sensitivities ranged from 82.6 to 100% in analyses for immunoglobulin M and G antibodies. Compared with reference antigen strain 2591, strains 231 (a tick isolate from Canada) and NCH-1 (a human skin isolate from Wisconsin) resulted in higher antibody titers in an ELISA. Syphilitic sera cross-reacted in all tests regardless of the antigen used. Key immunodominant proteins are shared among the closely related strains of B. burgdorferi sensu lato tested, but it is suspected that variations in antigen compositions among these spirochetes may sometimes affect assay performance for detecting serum antibodies.

Animals↗

PubMed1993

Isolation of Leptospira interrogans serovar grippotyphosa from the skin of a dog.

Leptospira interrogans serovar grippotyphosa was isolated from the skin of a 14-year-old male dog with deteriorating health. Necropsy revealed numerous lesions characteristic of aged dogs, but no evidence of acute hepatitis or nephritis, which are common features of pathogenic Leptospira infections. Antibody to Leptospira was not detected in the dog's serum by microagglutination. Leptospires grew slowly in Barbour-Stoenner-Kelly medium, a medium commonly used to isolate Borrelia, but then grew abundantly in Tween 80-bovine albumin leptospire medium. The isolate was pathogenic to a hamster and was identified by microagglutination and restriction endonuclease analysis.

Animals↗

PubMed1993

Spatial and temporal patterns of Ixodes scapularis (Acari: Ixodidae) in southeastern Connecticut.

The spatial distribution and abundance of host-seeking Ixodes scapularis Say (formerly I. dammini) were studied in 10 residential sites in woodlands during 1989-1991. In total, 7,385 larval, 2,202 nymphal, 164 female, and 248 male I. scapularis were collected in Old Lyme, Lyme, East Haddam, and Chester, CT. The majority of host-seeking I. scapularis larvae (84.2%) and nymphs (73.5%) were collected within the woodland plots, whereas a large proportion of the adults were recovered from lawn (36.4%) and transitional areas between lawns and forest (20.9%). The majority (71.1% of 1,244) of all stages of I. scapularis on the lawn were recovered within 1 m of the lawn edge, particularly along woods and stone walls. In contrast, most of the I. scapularis (60.0% of 3,065) collected in the woods were > 3 m from any defined edge and ticks were recovered throughout the forested plots. The abundance of nymphs on the lawns (1.0-29.4 nymphs per ha per sample) and in the woods (17.3-271.5 nymphs per ha per sample) varied significantly among the 10 residences during June and July. The average rate of infection by Borrelia burgdorferi, the causal agent of Lyme disease, in the nymphs was 14.2, 14.1, and 15.5% for 1989, 1990, and 1991, respectively. The abundance of I. scapularis nymphs in the forest was significantly higher in June 1991, than in 1989 or 1990. The risk of exposure to infected nymphs of I. scapularis varied spatially with the landscape and individual residence, and temporally.

Animals↗

PubMed1993

Serologic evidence of canine and equine ehrlichiosis in northeastern United States.

In a retrospective study, indirect fluorescent-antibody staining methods were used to detect immunoglobulins to Ehrlichia canis and Ehrlichia risticii in canine and equine sera that had originally been analyzed for antibodies to Borrelia burgdorferi. Analyses of 60 dog serum specimens collected in Connecticut and New York State during 1986 revealed antibodies to E. canis in 7 (11.7%) specimens; titration endpoints ranged from 1:40 to 1:320. Three of these dogs had anemia. Of the 187 equine serum specimens obtained in Connecticut during 1985 and analyzed by indirect fluorescent-antibody staining methods, 17 (9.1%) contained antibodies to E. risticii. Maximal antibody titers of 1:1,280 were recorded for serum specimens collected from three equids during May and July. We conclude that canine and equine ehrlichiosis coexist with Lyme borreliosis in Connecticut and the lower Hudson River Valley of New York State.

Animals↗

PubMed1993

Serologic analysis of dogs, horses, and cottontail rabbits for antibodies to an antigenic flagellar epitope of Borrelia burgdorferi.

Enzyme-linked immunosorbent assays (ELISA) and immunoblots using either whole-cell lysates of Borrelia burgdorferi or an antigenic region of flagellin (41-G) as the antigen were performed, and the abilities of the two assays to detect antibodies to this spirochete in dog, cottontail rabbit, and horse sera were compared. Assays using whole-cell B. burgdorferi lysates as the antigen were more sensitive for detecting antibodies. ELISA with 41-G as the antigen were specific for Borrelia antibodies but were not as sensitive as the assays with whole-cell lysates coated to the solid phase. Use of recombinant full-length flagellin, rather than 41-G, as the antigen in immunoblots increased the sensitivity of each assay. However, antibodies to other bacterial antigens cross-react with whole flagellin and may account for false-positive results. Antibodies to B. burgdorferi outer surface protein A or B were usually undetected when the sera were tested by immunoblotting methods. Borrelia lysates or the 41-G antigen may be used in ELISA or immunoblots to document host exposure to this spirochete. The use of 41-G as the antigen may increase the specificity of an assay or help confirm the serologic diagnosis of Lyme borreliosis in dogs, horses, and cottontail rabbits.

Animals↗

PubMed1992

Epizootiology of Lyme disease and methods of cultivating Borrelia burgdorferi.

Lyme disease is prevalent over vast areas of land in the northern hemisphere. The etiologic agent is a spirochete, Borrelia burgdorferi, that is transmitted by Ixodes ticks. At least five species of anthropophilic ticks are competent vectors, and the causative agent or closely related species have been detected in 20 wild or domestic mammals and eight birds. The ability to isolate and culture B. burgdorferi from humans, ticks, and wildlife has significantly contributed to our understanding of the epizootiology of Lyme disease. Specific procedures for isolating borreliae from ticks and rodents in Barbour-Stoenner-Kelly medium are described. The authors have preserved in liquid nitrogen more than 500 isolates from ticks, wildlife, and a human.

Animals↗

PubMed1992

Relationship between development of antibodies to Borrelia burgdorferi in dogs and the subsequent development of limb/joint borreliosis.

The relationship between antibody production and the subsequent development of limb/joint disorders of borreliosis was examined in dogs from south central Connecticut. Dogs without signs of illness, determined by physical examination, were selected from dogs being tested for Dirofilaria immitis. An ELISA was used to detect antibodies to Borrelia burgdorferi in 234 apparently healthy dogs during 1988. These dogs were monitored for 20 months after initial analyses to determine the prevalence of limb/joint disorder in seropositive and seronegative dogs. Of 234 dogs from which samples were initially obtained, 125 had antibodies to B burgdorferi and 109 were seronegative. The development of limb/joint disorder (eg, lameness, swelling, and signs of pain) accompanied by lethargy, fever, and inappetence in each group was nearly equal. Rates of 4.8% (6/125) and 4.6% (5/109) were recorded for seropositive and serosurvey of dogs, respectively. We conclude the serosurvey of apparently healthy dogs had no predictive value for the subsequent development of limb/joint disorder.

Animals↗

PubMed1992

Comparison of whole-cell antibodies and an antigenic flagellar epitope of Borrelia burgdorferi in serologic tests for diagnosis of Lyme borreliosis.

A recombinant protein (p41-G) of an antigenic region of flagellin was used in a standard and amplified enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Borrelia burgdorferi, the causative agent of Lyme borreliosis. Comparable sensitivities (88 to 94%) were noted when sera from 17 persons who had erythema migrans and antibodies to whole-cell B. burgdorferi were tested against the p41-G antigen. In tests of a second study group of 36 persons who had erythema migrans but no detectable antibodies to whole-cell B. burgdorferi, 3 (8%) were positive when the p41-G antigen was used. Assay specificity likewise increased when the p41-G fragment was included in an ELISA with human sera containing treponemal antibodies. Recombinant flagellar proteins of B. burgdorferi, such as the p41-G antigen, can be used in an ELISA and may help confirm Lyme borreliosis during early stages of infection and improve specificity.

Antibodies, Bacterial↗

PubMed1992

Antibodies to Borrelia burgdorferi in rodents in the eastern and southern United States.

Serologic studies were conducted to determine whether white-footed mice (Peromyscus leucopus) and cotton mice (Peromyscus gossypinus) contained serum antibodies to Borrelia burgdorferi, the causative agent of Lyme borreliosis. Enzyme-linked immunosorbent assays detected antibodies to this spirochete in 35.7 and 27.3% of 56 P. leucopus and 535 P. gossypinus serum samples, respectively, collected in Connecticut, North Carolina, South Carolina, Georgia, Florida, Alabama, and Mississippi. Antibody titers ranged from 1:160 to greater than or equal to 1:40,960. On the basis of adsorption tests, the antibodies detected appeared to be specific to Borrelia spirochetes. Seropositive rodents in the eastern and southern United States, areas where human cases of Lyme borreliosis have been reported, indicate a widespread geographic distribution of B. burgdorferi or a closely related spirochete.

Animals↗

PubMed1991

Babesia microti, human babesiosis, and Borrelia burgdorferi in Connecticut.

Babesia microti was isolated from a white-footed mouse (Peromyscus leucopus) that was captured in southeastern Connecticut in 1988, when the first human case of babesiosis acquired in Connecticut was recognized. To date, 13 cases of babesiosis have been reported in Connecticut, the largest number of human cases reported on the mainland United States. Two of nine patients quiried remembered a prior tick bite. Since Babesia parasites are known to be vectored only by ticks, we surmise that 12 of these infections were acquired via tick bites; 1 was obtained by blood transfusion (the patient was 46 years of age) from an endemically infected donor. The ages of the patients with tick-acquired babesiosis ranged from 61 to 95 years. Two patients died with active infections, and one patient died from chronic obstructive pulmonary disease soon after treatment with clindamycin and quinine. Indirect fluorescent-antibody titers of blood samples drawn at the time of hospitalization for 11 patients and at the time of active infection for 1 asymptomatic person ranged from 1:1,024 to 1:4,096. Five of eight patients with babesiosis also had significant immunoglobulin G or immunoglobulin M titers (1:640 to 1:5,120) to Borrelia burgdorferi. B. microti was isolated in Syrian hamsters inoculated with blood from 7 of 12 patients tested and was also isolated from mice captured in six towns. The peridomestic nature of the disease was demonstrated by isolating the parasite from white-footed mice captured in or near the yards of eight different patients. Of 59 mice tested, 27 were positive and 25 were coinfected with B. burgdorferi. The isolation of B. microti from a white-footed mouse captured in north-central Connecticut (West Hartford), away from the focus of human infections in southeastern Connecticut, suggests that this pathogen may spread into other areas where Ixodes dammini, the tick vector, becomes established.

Adult↗

PubMed1991

Rickettsiae and Borrelia burgdorferi in ixodid ticks.

Nymphs and adults of hard-bodied ticks were collected in Connecticut and tested by direct and indirect immunofluorescence staining methods for rickettsiae and Borrelia burgdorferi. Of the 609 Ixodes dammini ticks examined, 59 (9.7%) harbored rickettsialike microorganisms in hemocytes (blood cells). These bacteria reacted with fluorescein-conjugated antiserum to Ehrlichia canis, the etiologic agent of with fluorescein-conjugated antiserum to Ehrlichia canis, the etiologic agent of canine ehrlichiosis. Prevalence of infection ranged from 6.8 to 12.7% for males and females, respectively. Although the specific identities of the hemocytic rickettsialike organisms are unknown, they share antigens with ehrlichiae. Electron microscopy revealed rickettsiae in ovarian tissues of I. dammini that also had infected hemocytes. Rickettsialike organisms were also observed in the hemocytes of 5 (6.9%) of 73 Dermacentor variabilis ticks. In analyses for B. burgdorferi, 146 (23.7%) of 617 I. dammini ticks harbored these spirochetes in midguts. Hemocytic rickettsialike microorganisms coexisted with B. burgdorferi in 36 (6.7%) of the 537 nymphs and adults of I. dammini examined. I. dammini, with its broad host range, has the potential to acquire multiple microorganisms.

Animals↗

PubMed1991

Spotted fever group rickettsiae or Borrelia burgdorferi in Ixodes cookei (Ixodidae) in Connecticut.

Immatures and females of Ixodes cookei, a hard-bodied tick, were collected from woodchucks and other mammals in the northeastern United States and examined for spotted fever group rickettsiae and Borrelia burgdorferi. Of the 93 nymphs analyzed by a hemolymph test, 4 (4.3%) harbored rickettsiae. Six (15%) of 40 females were also infected. All infected ticks were collected from woodchucks in Connecticut. Indirect fluorescent antibody staining of midgut tissues from 128 nymphs revealed B. burgdorferi in two (1.6%) ticks, whereas larval and female ticks were negative. Further consideration should be given to I. cookei as a possible vector of spotted fever group rickettsiae or spirochetes that cause Lyme borreliosis.

Animals↗

PubMed1991

Adsorption and biotin-streptavidin amplification in serologic tests for diagnosis of Lyme borreliosis.

Serum samples from persons with Lyme borreliosis, periodontitis, or acute necrotizing ulcerative gingivitis were analyzed by an enzyme-linked immunosorbent assay (ELISA) with and without adsorption and amplification procedures. When biotin and streptavidin reagents were used as an amplification procedure in ELISA without the use of commercially prepared sorbent (Treponema phagedenis biotype Reiter), sensitivity increased. Of the 85 serum samples collected from persons with erythema migrans but no detectable antibodies to Borrelia burgdorferi by standard ELISA, 17 (20%) were reactive after amplification. Adsorption of serum samples with a 1:10 dilution of T. phagedenis biotype Reiter sorbent used in conjunction with amplified ELISA also improved the sensitivity of this method. However, cross-reactivity could not be completely eliminated. An adsorbed-amplified ELISA may be helpful in the diagnosis of Lyme borreliosis in the laboratory, particularly during early weeks of infection, when antibodies to B. burgdorferi can be present at a low concentration.

Antibodies, Bacterial↗

PubMed1991

Antibodies to Borrelia burgdorferi in deer and raccoons.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect serum antibodies to Borrelia burgdorferi, the causative agent of Lyme borreliosis, in deer (Odocoileus virginianus) and raccoons (Procyon lotor). Blood samples were collected from these mammals in Connecticut, Maryland, North Carolina, Georgia and Florida. Seropositivity for deer was highest in Connecticut (56% of 353 sera) and Maryland (51% of 35 sera). Raccoons in Connecticut, Maryland, North Carolina, and Florida also had antibodies to B. burgdorferi, but prevalence of positive sera was highest in Maryland (79% of 14 samples). Based on adsorption tests, the immunoglobulins detected in these mammals were probably specific to B. burgdorferi. The ELISA was more sensitive than an indirect fluorescent antibody staining method and was more suitable for analyzing large numbers of serum samples.

Animals↗