Presence Of anti-B Research Articles

Endemisation and management of Babesia divergens on a beef production farm

The hard tick Ixodes ricinus transmits a variety of zoonotic pathogens, including Babesia divergens, the most common cause of bovine babesiosis in northern Europe. In endemic areas, cattle are rarely clinically affected, as animals up to the age of nine months are resistant against relevant clinical disease and develop protective premunity. However, outbreaks in immunologically naïve herds may lead to considerable losses. Such an outbreak with a high mortality rate occurred in 2018 on a northern German beef production farm, as previously reported. The present study provides an update on the epidemiological situation and management strategy of the farm. In spring 2022, blood samples were taken from 46 animals for PCR and serological testing before pasture turnout. Although no clinical cases had been noticed since 2019, B. divergens DNA was detected by quantitative real-time PCR (qPCR), followed by amplification and sequencing of the 18S rRNA gene, in 6.5% (3/46) of cattle blood samples. Presence of anti-B. divergens antibodies was confirmed in 26.1% (12/46) of animals, while further 10.9% (5/46) had a borderline antibody titre. The antibody status of 23 of these animals had already been determined in 2018 and/or 2020, revealing fluctuating titre patterns indicative of repeated pathogen exposure. Moreover, 457 questing I. ricinus specimens collected on the farm’s pastures and 83 I. ricinus specimens detached from cattle were screened for Babesia spp. DNA by qPCR, followed by 18S rDNA amplification and sequencing. Endemisation of B. divergens was confirmed by 0.9% (4/457) positive questing I. ricinus, while the ticks detached from cattle were Babesia-negative. The farm’s management strategy includes annual metaphylactic treatment with imidocarb dipropionate during the main tick exposure period in spring. However, the antibody titre fluctuations and the persistent infections at the end of the housing period indicate that the absence of clinical disease is primarily due to a rising level of premunity. Metaphylactic treatment with imidocarb seems to be a suitable management option to protect newly acquired immunologically naïve animals. The endemisation of B. divergens is also of public health significance, as the pastures are located close to a tourist destination in a popular hiking area.

Detection of Weak “B” Phenotype While Resolving an ABO Discrepancy

Quantitative and/or qualitative differences in ABO phenotypes give rise to ABO discrepancies causing difficulties in establishing the accurate phenotype. These discrepant serological reactions result in significant delays in blood bank. The correct typing of the blood group is imperative to prevent ABO incompatibility issues. However, the discrepant results encountered in routine settings are a challenge to immunohematologists. The variants of the ABO occur very rarely particularly true for B subgroups. Here, we present a case study of a healthy blood donor, discrepant results in forward and reverse blood grouping led us to perform adsorption-elution test. The presence of anti-B in the eluate confirmed the presence of weaker variant of B antigen on the surface of red blood cells. Correct identification of blood group is mutually important for donor and recipient to prevent the occurrence of any transfusion reaction. The serologically determined weak B phenotypes, however, require further confirmation through genomic analysis.

A Clinical Case of Weak A Antigen on the Erythrocytes in a Person with Coexistent Anti-A Antibodies.

This study investigated a person with an AB0 discrepancy. Her blood group initially typed at the birth as AB Rh+ (positive); however, it was B Rh+ (positive) or Rh- (negative) when she was in her teens. At room temperature, her erythrocytes were agglutinated by anti-B, and the agglutination was significantly weaker at 37 ºC. As a result, her erythrocytes did not absorb anti-B but anti-A. Furthermore, her erythrocytes were agglutinated by anti-A at 37 ºC with signs of hemolysis in the presence of complement. The unwashed erythrocytes were also agglutinated in an antiglobulin test by polyclonal anti-A at 37 ºC and by heated polyclonal anti-A and anti-A MAB 2-8 at room temperature. Moreover, her serum agglutinated A erythrocytes at room temperature with less activity at 37 ºC; however, it agglutinated B erythrocytes at 37 ºC. The ability of the erythrocytes of this person to absorb anti-A came along with the agglutination of her erythrocytes at 37 ºC by polyclonal serum and decreased activity of the serum to agglutinate A erythrocytes at 37 ºC, compared to room temperature. The absence of anti-B absorbance by the person’s erythrocytes was accompanied by the presence of anti-B in the serum, which was active at 37 ºC. The incubation of the person’s serum with 0 erythrocytes induced the ability of erythrocytes to absorb anti-A and to be hemolyzed by anti-A in the presence of complement in accordance with the person’s characteristics of erythrocytes. The reaction of absorption and agglutination at room temperature and 37 ºC by heated serum with the use of complement may help to reveal both weak A and B antigens and anti-A and anti-B antibodies while AB0 blood typing.

Detection of canine vector-borne diseases in eastern Poland by ELISA and PCR.

The aim of the study was to establish the prevalence of Ehrlichia canis, Anaplasma phagocytophilum and Borrelia burgdorferi in dogs in eastern Poland and to determine the factors associated with exposure (seroposity) or infection (PCR). Anti-A. phagocytophilum, anti-B. burgdorferi and anti-E. canis antibodies were determined in 400 dogs, using the SNAP 4Dx ® test (IDEXX Laboratories). In addition, PCRs were performed for the detection of E. canis, A. phagocytophilum and B. burgdorferi DNA. In reference to the risk factor analysis, a regression logistic model was determined for each aetiological agent. The overall seroprevalence was highest for B. burgdorferi (11.0 %), followed by A. phagocytophilum (8.0 %) and E. canis (1.5 %). Eleven healthy dogs were found to be infected with A. phagocytophilum, as determined by PCR, while the remainder were seronegative. For B. burgdorferi, the DNA of the spirochetes was detected in the blood of 20 dogs, while the presence of anti-B. burgdorferi IgG was detected in the sera of ten of these. For E. canis, none of the dogs tested positive by PCR. Tick control was included as a protective factor for A. phagocytophilum and B. burgdorferi, while the origin (rural) was included as a risk factor for B. burgdorferi and A. phagocytophilum infection. In addition, breed (pure) was a risk factor for B. burgdorferi infection, and sex (female) was a risk factor for E. canis.

Borrelia burgdorferi, a great chameleon: know it to recognize it!

Borrelia burgdorferi is a spirochaete that can penetrate the blood-brain barrier in early infection and can cause endothelial damage other than central nervous system lesions. We describe a clinical case of neuroborreliosis that occurred in the absence of classical erythema migrans or arthralgia. Magnetic resonance imaging findings compatible with simil-vasculitis and demyelinating lesions associated with the presence of anti-B. burgdorferi antibodies in the plasma or cerebrospinal liquid is an indication for antimicrobial treatment against B. burgdorferi. An early diagnosis and a prompt establishment of an adequate antibiotic treatment is needed for a successful recovery.

Reactivity of anti-Blomia tropicalis IgG and IgE in patients with atopic dermatitis.

Patients with atopic dermatitis (AD) commonly develop antibodies of subclasses IgG and IgE to house dust mites, such as Dermatophagoides pteronyssinus and D. farinae. The domestic mite Blomia tropicalis is prevalent in Brazil and can cause the exacerbation of AD. The objectives of this study were to assess skin reactivity to B. tropicalis extracts of AD patients and a control group of nonallergic subjects, and to determine the in vitro reactivity of anti-B. tropicalis IgG and IgE in the serum of AD patients and a control group of nonallergic individuals. Subjects were 36 patients with confirmed AD and the controls were 25 nonallergic individuals. Skin sensitivity to B. tropicalis extracts was tested by the prick-test, and anti-B. tropicalis IgG reactivity in the serum was detected by the Western blot. Anti-B. tropicalis IgE reactivity in the serum was measured by RAST. Patients with AD reacted 7.12 times more often to extracts from B. tropicalis than the control group. A positive association was observed between the presence of anti-B. tropicalis IgG and IgE and AD. AD patients showed a high degree of sensitization to B. tropicalis; it can thus be considered a risk factor for the development of AD exacerbations in patients exposed to this mite species.

Population dynamics of a naturally occurring heterogeneous mixture of Borrelia burgdorferi clones.

Two unique isolates of Borrelia burgdorferi, differing in plasmid content and outer surface protein C expression, were cultured on sequential captures of a single free-living Peromyscus leucopus mouse and were examined for differences in transmissibility. Both isolates were transmissible from inoculated C.B-17 mice to larval Ixodes scapularis ticks and, subsequently, from infected nymphal ticks to C3H/HeJ mice. Plasmid and protein analyses suggested that the original isolates were a mixed population of B. burgdorferi, and cloning by limiting dilution resulted in the identification of two clonal groups. In addition to being heterogeneous in plasmid and genomic macrorestriction analyses, the clones varied with respect to the electrophoretic mobilities and antigenicity of their OspC proteins, as shown by their reactivity to a panel of monoclonal antibodies. Plasmid analysis of sequential isolates from C3H mice experimentally infected with the primary isolate or various mixtures of its subclones showed an apparently random fluctuation in clonal dominance in the majority of mice. Surprisingly, mice infected with each subclone were permissive to superinfection with the heterologous subclone, despite the presence of anti-B. burgdorferi antibodies at the time of the secondary challenge. These results show conclusively that mice captured at Lyme disease enzootic sites may be infected by mixed populations of genetically and antigenically distinct B. burgdorferi clones and that these infections can be acquired by coinfection or by sequential infection. The lack of cross-immunization between clones existing within a naturally occurring population may play a role in the maintenance of the genetic heterogeneity of B. burgdorferi in nature.