Spatio-Temporal Distribution of Brucellosis in European Terrestrial and Marine Wildlife Species and Its Regional Implications.

Brucellosis is an important bacterial zoonosis of domestic and wildlife species. This disease has a significant public health concern and is characterized by reproductive failure resulting in economic losses in the livestock industry. Among thirteen known species, B. abortus, B. melitensis, B. suis, and B. canis are human pathogens. Brucellosis has been extensively investigated in humans and domestic animals. However, the situation in wildlife is still not completely reported and studied. Therefore, a systematic literature search and screening were done to clarify the situation of brucellosis in wildlife in Europe. Sixty-five articles from a total of 13,424 reports published between 1991 and 2021 were selected, applying defined inclusion criteria. Wild boars and brown hares were the most often studied terrestrial wildlife species, whereas seals and porpoises were the most often investigated marine wildlife. Poland, Croatia, and Belgium showed the highest seroprevalences of wild boars caused by B. suis biovar 2. In marine wildlife, brucellosis was mainly caused by B. ceti and B. pinnipedialis. Most samples were from carcasses. Thus, sera could not be collected. It is worrisome that B.abortus and B. melitensis were reported from both terrestrial and marine wild animals, posing a zoonotic threat to people exposed to wild animals. Currently, there is no approved vaccine available for wild animals. The main challenges are the development of specific diagnostics and their validation for use in wildlife.

Investigating the use of protein saver cards for storage and subsequent detection of bovine anti-Brucella abortus smooth lipopolysaccharide antibodies and gamma interferon.

Brucella abortus, a smooth strain of the genus Brucella, is the causative agent of bovine brucellosis. To support the ongoing development of diagnostic tests for bovine brucellosis, the use of Protein Saver cards (Whatman) for bovine blood serum and plasma sample collection has been evaluated. These cards offer significant logistical and safety alternatives to transporting and storing liquid samples and may aid in diagnostic programs and validation studies. To evaluate the utility of these cards, 204 bovine blood serum samples from Brucella-infected and noninfected animals were stored on and eluted from the Protein Saver cards. Anti-Brucella smooth lipopolysaccharide (sLPS) antibody titers for the serum eluates were compared to those of the unprocessed original serum samples by indirect enzyme-linked immunosorbent assay (ELISA). The results showed a highly significant correlation between titers from the serum eluates and the unprocessed sera. Therefore, under these circumstances, serum eluates and unprocessed serum samples may be used interchangeably. Blood plasma from 113 mitogen-stimulated whole-blood samples was added to and eluted from the Protein Saver cards. The gamma interferon (IFN-γ) titers in the plasma eluates were compared to those of the unprocessed plasma samples obtained by IFN-γ ELISA. The results showed a significant correlation between the plasma eluates and the unprocessed plasma samples. To derive a signal in the plasma eluate, it was necessary to develop a novel and highly sensitive ELISA for the detection of IFN-γ. The serum samples stored on cards at room temperature over a 10-day period showed little variation in antibody titers. However, the plasma eluates showed a progressive loss of IFN-γ recovery over 10 days when stored at room temperature.

[Investigation of Brucella canis seropositivity by in-house slide agglutination test antigen in healthy blood donors]. / Saglikli Kan Donörlerinde Brucella canis Seropozitifliginin Laboratuvar Yapimi Lam Aglütinasyon Test Antijeni ile Arastirilmasi

Canine brucellosis which is due to Brucella canis, is transmitted to man by infected dogs or their secretions. The symptoms of canine brucellosis are similar to the symptoms of brucellosis caused by other Brucella species and endocarditis or meningitis may develop in untreated cases. There is limited data regarding B.canis infections in man and the current status of the disease is insufficiently evaluated in our country. Serological diagnosis of brucellosis is classically based on standard slide and tube agglutination tests. However, the antigens used in these tests detect antibodies that develop against species (B.melitensis, B.abortus, B.suis) with "smooth" lipopolysaccharides in their cell wall. B.canis has "rough" lipopolysaccharide in its cell wall and thus these classical tests can not detect antibodies against B.canis. Besides there is no commercial slide agglutination test which uses B.canis antigens. The aim of this study was to investigate the B.canis seropositivity by slide agglutination test (SAT), using homemade B.canis antigen, in healthy subjects and to determine the prevalence of B.canis infection in our population. A total of 1930 blood donors (age range: 18-55 years) who were admitted to the blood donation centers of different hospitals in Kocaeli province (located at Northwestern part of Turkey) between January-December 2010, have been included in the study. All of the subjects were negative in terms of Rose-Bengal plate test (B.abortus antigen test). Undiluted serum samples were initially screened by SAT, and those which were found positive were retested by SAT in the dilutions of 1/25 - 1/200. Confirmation of the positive results was performed by using 2-mercaptoethanol (2-ME) SAT. The test antigen (Alton antigen) was prepared from the less mucoid M(-) variant of B.canis, and 1/1048 titered dog antiserum was used as positive control. Of the 1930 blood donors sera, 40 (2.1%) were found positive with SAT, whereas 16 of them yielded equivocal positive (12 were 1/50, 4 were 1/100 titers) and 15 yielded positive (≥ 1/200 titer) results with 2-ME SAT. As a result, B.canis seropositivity rate in the healthy subjects in this study was estimated as 1.6% (31/1930). The integration of B.canis SAT to the routine serological tests applied for brucellosis diagnosis might aid to the data related to brucellosis epidemiology. B.canis seroprevalence determined as 1.6% in this study supplied a basic data about the infection in our country. However, larger scale, multicenter studies with different patient and risk groups should be conducted to further evaluate the epidemiology of B.canis infections in Turkey.

A serological diagnostic survey for Brucella canis infection in Turkish patients with Brucellosis-like symptoms.

The incidence of Brucella canis infection in humans is unknown in Turkey. In this study, we investigated the prevalence of B. canis infection in human sera obtained from six regions in Turkey and comparatively evaluated the results obtained by agglutination-based techniques using standardized antigens made from B. canis. The patients (n = 1,746) presented with clinical symptoms that were similar to those of brucellosis. All patients who tested negative in the Rose Bengal test for the smooth Brucella strains (abortus, melitensis, and suis) were screened for evidence of B. canis infection using the rapid slide agglutination test (RSAT), the microagglutination test (MAT), and the 2-mercaptoethanol RSAT test (2ME-RSAT). Of the samples tested, 157 (8.9%), 68 (3.8%), and 66 (3.7%) were positive for B. canis, as determined by RSAT, MAT, and 2ME-RSAT, respectively. The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of RSAT were 100%, 94.6%, 42%, and 100%, respectively, and of MAT were 100%, 99.9%, 97%, and 100%, respectively. We recommend the routine use of MAT and 2ME-RSAT to check the sera of all patients with symptoms of brucellosis who are negative for brucellosis using a smooth Brucella antigen.

Genotyping of Brucella melitensis by rpoB gene analysis and re-evaluation of conventional serotyping method.

In Turkey, where brucellosis is endemic, a comparison of conventional and molecular genotyping methods has not been published to date. In this study, we investigated the efficacy of single nucleotide polymorphism (SNP) analysis of rpoB gene in the genotyping of Brucella melitensis strains by sequencing. In light of the molecular genotyping method available now in Turkey, the adequacy of serological typing alone should be re-evaluated as a tool for epidemiologic studies of B. melitensis.

[Species and biovar distribution of Brucella isolates in Trakya University Hospital between 1997-2002]. / Trakya Universitesi Hastanesinde 1997-2002 yillari arasinda saptanan Brucella izolatlarinin tür ve biyovar dagilimi.

The aim of this study was to evaluate the species and biovar distribution of Brucella spp. isolated from blood cultures in Clinical Microbiology Laboratory of Trakya University Hospital, between 1997-2002. A total of 48 Brucella spp. have been isolated from 14.815 patients (0.3%), and the strains were identified according to CO2 requirement, H2S production, basic fuchsin and thionin sensitivity, lysis by Tbilisi phages, and presence of agglutination with monospecific A and M antisera. As a result, 47 (97.9%) isolates were identified as B. melitensis, and one as B. abortus (2.1%). Forty two (89.4%) of B. melitensis isolates were biovar 3, and five (10.6%) were biovar 1, while the single isolate of B. abortus was identified as an atypical strain.