New developments in the diagnostic procedures for zoonotic brucellosis in humans

Federal Institute for Risk Assessment, Diedersdorfer Weg 1, D-12277 Berlin, Germany.
Revue scientifique et technique (International Office of Epizootics) (Impact Factor: 0.91). 04/2013; 32(1):177-88.
Source: PubMed


At present, laboratory diagnosis of human brucellosis is based on isolation of the bacteria from clinical samples followed by standard microbiological tube testing, detection of anti-Brucella antibodies using various serological tests, and the use of molecular methods for the detection of Brucella DNA. None of these diagnostic tools can be used on its own to reliably detect the causative agent. Cultures give a low yield and subsequent phenotypic characterisation is time consuming, meaning that the initiation of adequate antibiotic therapy is frequently delayed. Serological tests seem to be more effective but are not internationally standardised. Moreover, antibodies can remain detectable despite successful therapy, cross-reacting antibodies may occur, and variable cut-offs for different levels of endemicity are lacking. Molecular assays may reduce diagnostic delays in clinical laboratories, but diagnostic criteria for active infection have not yet been defined. This article reviews the latest microbiological methods for the diagnosis of human brucellosis and outlines developments for the future.

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    • "The isolation rate of Brucella is poor due to its slow growth rate, the low quantity of circulating viable bacteria, and problems with standardization of the culture medium and blood culture techniques employed, as well as the presence of antibiotics that inhibit growth (Yagupsky, 1999). The demonstration of antibodies generated against Brucella using serological tests remains a viable alternative to culture, and several serological tests, such as the Rose Bengal plate agglutination test (RBPT) and a standard tube agglutination test (STAT) are the most popular serological tests used in the field for the diagnosis of brucellosis (Morgan et al., 1969; Ruiz-Mesa et al., 2005; Gómez et al., 2008; Chachra et al.,2009; Araj, 2010; Al Dahouk et al., 2013). Enzyme-linked immunosorbent assay (ELISA) format offers high sensitivity and specificity in addition to a field-usable format (Jubier-Maurin et al., 2001; Thavaselvam et al., 2010). "
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    ABSTRACT: Brucellosis is a highly infectious zoonotic disease and an economically important infection of humans and livestock with a worldwide distribution. The main mode of transmission of this disease to humans is through the consumption of infected milk, milk products and uncooked or raw meat. The present study was designed to prepare few native antigens i.e. sonicated antigen, cell envelope antigen and freeze and thaw antigen from Brucella abortus S99 culture and to test them in a highly sensitive and specific indirect ELISA in both a microtitre plate and dot-blot format for the development of field based diagnosis. All 50 suspected bovine samples were tested by plate as well as in dot ELISA formats for all the three antigens prepared. The cell envelope antigen was found to be more suitable as it had the maximum agreement with the RBPT results followed by the sonicated antigen and the least agreement was found with that of the freeze thaw antigen. This detection system in microtitre plates and a dot-blot format will be useful for the rapid screening samples for the disease surveillance and routine diagnosis.
    • "Attempts to isolate the pathogen from tissue samples of affected animals for further phenotypic and genetic characterization failed. It is well known that the isolation of brucellae from molecularly or serologically positive-tested clinical samples rarely succeeds (Truong et al., 2011), because of the diverging sensitivities of these methods (Al Dahouk et al., 2013). Furthermore, the relatively short survival of rodent-and shrew-specific brucellae in small mammals and the sampling procedure in our study seems to be unfavourable for bacterial isolation. "
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    ABSTRACT: Brucellosis is a widespread zoonotic disease introduced from animal reservoirs to humans. In Germany, bovine and ovine/caprine brucellosis were eradicated more than a decade ago and mandatory measures in livestock have been implemented to keep the officially brucellosis-free status. In contrast, surveillance of wildlife is still challenging, and reliable data on the prevalence of brucellae in small mammal populations do not exist. To assess the epidemiology of Brucella spp. in rodents and shrews, a molecular survey was carried out. A total of 537 rodents and shrews were trapped in four federal states located throughout Germany and investigated for the presence of Brucella. Using a two-step molecular assay based on the detection of the Brucella-specific bcsp31 and IS711 sequences in tissue samples, 14.2% (n = 76) of the tested animals were positive. These originated mainly from western and south-western Germany, where preliminary analyses indicate population density-dependent Brucella prevalence in voles (Myodes glareolus) and mice (Apodemus spp.). recA typing revealed a close relationship to a potentially novel Brucella species recently isolated from red foxes (Vulpes vulpes) in Austria. The molecular detection of brucellae in various rodent taxa and for the first time in shrew species shows that these animals may be naturally infected or at least have a history of exposure to Brucella spp.
    Transboundary and Emerging Diseases 09/2015; DOI:10.1111/tbed.12425 · 2.94 Impact Factor
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    • "The organism is intracellular, coccobacilli, Gram-negative bacteria of the genus Brucella which consists of ten species ranked according to their host preferences namely, B. abortus (cattle), B. melitensis (small ruminants and camels), B. suis (swine), B. canis (dog) which also affect man, B. ovis (sheep), B. neotomae (desert woodrat), B. ceti (cetaceans), B. pinnipedialis (pinnipeds) are species isolated from marine mammals and occasionally cause infection in man, Brucella inopinata (human breast) (Scholz et al., 2009; Martín-Martín et al., 2011 and Falenski et al., 2011). Human brucellosis is a zoonotic disease with a major impact on public health, even though successful eradication and control programmes for domestic animals have been established in many developed countries around the world (Al Dahouk et al., 2013). More than 500,000 human cases are reported worldwide each year particularly from developing countries (Seleem et al., 2010). "

    08/2015; 7(8):253-257. DOI:10.5897/JPHE2015.0738
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