Search Results

You are looking at 1 - 10 of 11 items for

  • Author or Editor: Louis A. Magnarelli x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

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 seronegative dogs, respectively. We conclude that serosurvey of apparently healthy dogs had no predictive value for the subsequent development of limb/joint disorder.

Free access
in Journal of the American Veterinary Medical Association

Summary

Multiple blood samples were obtained from privately owned dogs living in tick-infested areas of New York (Westchester County) and Connecticut, where Lyme disease in human beings has been reported. Of the 175 dogs examined, 127 (72.6%) had limb/joint disorder, whereas the remaining 48 dogs were considered healthy. Results of analysis of 419 serum samples revealed IgM antibody to Borrelia burgdorferi in healthy and lame dogs during all seasons. Prevalence of seropositivity was significantly (P < 0.01) greater, using a polyvalent elisa (89.5%) than using a class-specific elisa for IgM antibody (57.8%). Mean antibody titers obtained by use of polyvalent elisa were likewise higher than IgM titers. Analysis of paired serum samples from dogs with limb/joint disorder indicated that 118 (92.9%) remained positive for IgM or IgG antibodies when retested weeks or months after initial testing. In 48 dogs without history of joint involvement or other signs of disease, 43 (89.6%) had antibody to B burgdorferi 2 or more times. Serotest results also revealed little or no change in antibody titer for lame dogs given antibiotics or for healthy dogs 2 or more months after initial sample collection.

Free access
in Journal of the American Veterinary Medical Association

Summary

Ticks were removed from naturally infested cats, and serum samples from these cats were tested for antibodies to Borrelia burgdorferi. Twenty-two of 93 cats (23.7%) had one or more motile stages of Ixodes dammini attached. Of 2 larvae and 20 nymphs removed from cats, 1 larva and 2 nymphs were infected with B burgdorferi. Spirochetes were not found in tissues of 13 female and 4 male ticks. Ten of 71 serum samples analyzed by indirect fluorescent antibody staining or elisa contained antibodies to this spirochete. Maximal antibody titers were 1:256 and 1:2,560, respectively. At titers ≥1:160 in elisa, seropositivity ranged from 8.8% (n = 34 sera tested from 34 cats) in May through July to 33.3% (n = l2 cats tested) during February through April. In clinical studies of 30 cats, there were nearly equal percentages of seropositive cats with limb or joint disorders not accompanied by fever, anorexia, or fatigue (5 of 21 cats) and cats with these signs of illness but lacking lameness (2 of 9 cats.)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether cats in the northeastern United States develop serum antibodies against antigens of Borrelia burgdorferi and Anaplasma phagocytophilum and whether coinfection with the 2 organisms occurs.

Sample Population—Serum samples from 84 healthy cats and 9 cats with lameness, fever, anorexia, or fatigue.

Procedure—Serum antibodies against B burgdorferi and A phagocytophilum were measured with an ELISA incorporating a whole-cell preparation or purified recombinant antigens, by means of western blot analysis, or indirect fluorescent antibody (IFA) staining.

Results—ELISA results indicated that 44 of 93 (47%) sera contained antibodies against ≥ 3 B burgdorferi antigens, whereas 43 (46%) were reactive to wholecell B burgdorferi. Serum reactivity to protein 35, VlsE, and outer surface proteins A and F was most common. Seropositivity to ≥ 3 antigens occurred at the same rate (5/9) in the 9 ill cats as in the 84 healthy cats (46% [39/84]). Of 13 sera reactive to recombinant antigens, 9 were seropositive as measured by western blot testing with whole-cell antigen. Seropositivity rates of 30% and 38% were detected for antibodies against A phagocytophilum via IFA and ELISA testing, respectively. Fifteen (16%) sera had antibodies against both pathogens.

Conclusions and Clinical Relevance—Cats living in areas infested by Ixodes scapularis ticks are exposed to B burgdorferi and A phagocytophilumand, in some instances, may be coinfected. Most cats appeared healthy. An ELISA incorporating specific recombinant antigens may be used adjunctively with western blot and other assays to confirm B burgdorferi and A phagocytophilum infection in cats. (Am J Vet Res 2005;66:1895–1899)

Full access
in American Journal of Veterinary Research

Objective

To characterize antibody response in horses with clinical signs of Ehrlichia equi infection.

Design

Prospective study.

Animals

13 horses with confirmed acute E equi infection.

Procedure

Sequential serum sampling was performed in Connecticut and New York during 1995 and 1996 to identify horses with naturally acquired equine granulocytic ehrlichiosis (EGE). Horses with clinical signs of EGE (ie, fever without respiratory involvement) were confirmed as having E equi infection by polymerase chain reaction detection of ehrlichial DNA and by a minimum fourfold increase in total antibody titer by indirect fluorescent antibody staining methods. Infection was corroborated by use of DNA sequencing.

Results

11 of 13 horses did not have detectable antibody in serum samples obtained at onset of disease. Seroconversion was evident in samples obtained 19 to 81 days thereafter. Median time to peak antibody response was 46 days after onset and median titer was 1:320. For 11 of 13 horses, antibody titers were ≤ 1:40 by 215 days after onset.

Clinical Implications

E equi was found in horses in the northeastern United States and caused EGE. Concentration of antibodies to E equi increased within 19 to 81 days of disease onset and were low during early weeks of infection. Therefore, antibody detection may be of limited value for early serologic diagnosis. We suggest that disease may develop from a reinfection, and retrospective serologic studies to determine exposure to E equi may reflect a disproportionate number of negative reactions. (J Am Vet Med Assoc 1998;212:1910–1914)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To develop and evaluate a polyvalent ELISA incorporating a highly specific recombinant antigen (p44) for diagnosis of granulocytic ehrlichiosis in dogs and horses.

Animals—32 dogs and 43 horses.

Procedure—Results of the ELISA were compared with results of indirect fluorescent antibody (IFA) staining and western immunoblotting incorporating whole-cell antigen.

Results—For the canine and equine samples, percentages of samples with positive IFA staining, western immunoblotting, and ELISA results were similar. For 29 (91%) canine samples and 30 (70%) equine samples, results of IFA staining, western immunoblotting, and the ELISA were in complete agreement. Results of the ELISA for 3 canine serum samples known to contain antibodies to Ehrlichia canis and 12 equine serum samples known to contain antibodies to E risticii were negative.

Conclusions and Clinical Relevance—Results of the present study suggest that a polyvalent ELISA incorporating a recombinant p44 antigen is suitable for detecting antibodies to E equi in dogs and horses. ( Am J Vet Res 2001;62:29–32)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To test serum samples of dogs and horses by use of class-specific recombinant-based ELISA for establishing a diagnosis of granulocytic ehrlichiosis attributable to infection with organisms from the Ehrlichia phagocytophila genogroup.

Sample Population—Serum samples from 43 clientowned dogs and 131 horses (81 with signs of acute illness and 50 without signs of disease).

Procedure—Serum samples were analyzed, using ELISA with a recombinant 44-kd protein antigen for IgM and IgG antibodies to the human granulocytic ehrlichiosis (HGE) agent (NCH-1 strain). Western blot analyses, using infected human promyelocytic leukemia cells, were conducted on 38 serum samples of horses and 11 serum samples of dogs to verify reactivity to the 44-kd peptide.

Results—IgM or IgG antibodies to the HGE agent were detected in 5 to 28% of dog serum samples and 5 to 37% of horse serum samples. Thirty-five of 38 (92%) horse serum samples had corresponding results on both tests (2 positive results for 26 samples and 2 negative results for 9 samples), using an ELISA for IgG antibodies or immunoblotting for total immunoglobulins. All 11 serum samples of dogs had positive results for both methods.

Conclusion and Clinical Relevance—These ELISA with recombinant 44-kd antigen are suitable for detecting IgM or IgG antibodies to the HGE agent in serum samples of dogs and horses. Positive results for serum samples of horses from Connecticut, New York, Virginia, and Georgia indicate that the HGE agent is widely distributed in tick-infested areas of the eastern United States. (Am J Vet Res 2001;62:1365–1369)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether horses living in tick-infested areas of northeastern United States with clinical signs of borreliosis or granulocytic ehrlichiosis had detectable serum antibodies to both Borrelia burgdorferi and Ehrlichia equi.

Design—Prospective study.

Animals—Serum samples from 51 clinically normal horses, 14 horses with clinical signs of borreliosis, and 17 horses with clinical signs of granulocytic ehrlichiosis.

Procedure—Serum B burgdorferi or E equi antibodies were measured by use of an ELISA, immunoblot analysis, or indirect fluorescent antibody (IFA) staining.

Results—Of the 82 serum samples tested, 37 (45.1%) and 13 (15.9%) had detectable antibodies to B burgdorferior E equi, respectively. Test results indicated that 12 horses had been exposed to both agents, 11 of these horses had granulocytic ehrlichiosis. The ELISA regularly detected antibodies to the following recombinant protein (p) antigens of B burgdorferi: p29, p37, p39, and p41-G. The use of immunoblot analysis confirmed ELISA results by indicating antibody reactivities to antigens of whole-cell B burgdorferi having molecular masses of predominantly 31, 34, 37, 39, 41, 58, and 93 kd.

Conclusion and Clinical Relevance—Horses living in areas where ticks (Ixodes scapularis) abound are sometimes exposed to multiple pathogens. Analyses for specific recombinant borrelial antibodies using an ELISA can help separate horses with borreliosis from those with granulocytic ehrlichiosis, even when antibodies to both etiologic agents are detected in serum samples. Analysis using immunoblots is sensitive, and along with ELISA or IFA procedures, is suitable for confirming a clinical diagnosis of each disease (J Am Vet Med Assoc 2000;217:1045–1050)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To diagnose granulocytic ehrlichiosis in horses, compare results of indirect fluorescent antibody (IFA) staining procedures with those of immunoblot analysis, and compare serologic test findings with polymerase chain reaction (PCR) results.

Animals

69 horses with high rectal temperatures (≥ 39 C) and lethargy, anorexia, or limb edema.

Procedure

43 convalescent serum samples obtained from 38 horses 2 to 18 weeks after onset of illness were analyzed by use of immunoblot procedures and IFA staining methods, using the NCH-1 or BDS ehrlichial strains. Blood samples from 69 acutely ill horses were tested by PCR to detect ehrlichial DNA.

Results

Antibodies to Erlichial equi were detected in serum samples obtained during all seasons; seropositivity rates ranged from 50 to 93%. In IFA assays using the BDS or NCH-1 strain, seropositivity rates were 70 and 79%, respectively, whereas in immunoblot analyses using the NCH-1 strain, a seropositivity value of 79% was recorded. By immunoblot analysis, all serum samples of all seropositive horses were reactive to a protein having molecular mass of about 44 kd. Blood samples from 29 of 69 (42%) acutely ill horses contained ehrlichial DNA.

Conclusion and Clinical Relevance

Results of the various serologic testing procedures were in close agreement with each other. All serologic testing methods are suitable for laboratory diagnosis of equine granulocytic ehrlichiosis. (Am J Vet Res 1999; 60:631–635)

Free access
in American Journal of Veterinary Research