Rose Bengal test: diagnostic yield and use for the rapid diagnosis of human brucellosis in emergency departments in endemic areas

ABSTRACTThe aim of the present study was to analyse the diagnostic yield of the rose Bengal test for the rapid diagnosis of human brucellosis in an emergency department in an area where the disease is endemic. The study included 711 patients diagnosed initially with brucellosis and 270 controls. Brucellosis patients were divided into three groups: group I, individuals with no regular exposure to or history of brucellosis; group II, individuals exposed repeatedly to Brucella infection; and group III, individuals infected with Brucella who had received appropriate treatment during the previous 12 months. Blood cultures were positive for 445 (62.6%) brucellosis patients, while the remaining 266 (37.4%) patients were diagnosed according to clinical and serological criteria. The overall sensitivity of the rose Bengal test was 92.9%. The specificities for groups I, II and III were 94.3%, 91.7% and 76.9%, respectively, with positive likelihood ratios of 16.5, 10.4 and 4.2, respectively. The diagnostic gain after the performance of the rose Bengal test was good or very good in patients with no previous exposure to Brucella or history of brucellosis, but poor in patients who were exposed repeatedly to Brucella or had a history of brucellosis and a low pre-test probability. Use of the rose Bengal test as the sole technique for the diagnosis of brucellosis in endemic areas should be considered very carefully in the context of patients who are exposed repeatedly to Brucella or have a history of brucellosis

Identification of Brucella by MALDI-TOF Mass Spectrometry. Fast and Reliable Identification from Agar Plates and Blood Cultures

BACKGROUND: MALDI-TOF mass spectrometry (MS) is a reliable method for bacteria identification. Some databases used for this purpose lack reference profiles for Brucella species, which is still an important pathogen in wide areas around the world. We report the creation of profiles for MALDI-TOF Biotyper 2.0 database (Bruker Daltonics, Germany) and their usefulness for identifying brucellae from culture plates and blood cultures. METHODOLOGY/PRINCIPAL FINDINGS: We created MALDI Biotyper 2.0 profiles for type strains belonging to B. melitensis biotypes 1, 2 and 3; B. abortus biotypes 1, 2, 5 and 9; B. suis, B. canis, B ceti and B. pinnipedialis. Then, 131 clinical isolates grown on plate cultures were used in triplicate to check identification. Identification at genus level was always correct, although in most cases the three replicates reported different identification at species level. Simulated blood cultures were performed with type strains belonging to the main human pathogenic species (B. melitensis, B. abortus, B. suis and B. canis), and studied by MALDI-TOF MS in triplicate. Identification at genus level was always correct. CONCLUSIONS/SIGNIFICANCE: MALDI-TOF MS is reliable for Brucella identification to the genus level from culture plates and directly from blood culture bottles

Brucelosis, una zoonosis frecuente

En 1968 la Organización Mundial de la Salud afirmó que la brucelosis era responsable de más enfermedades, miserias y pérdidas económicas que cualquier otra enfermedad animal conocida que afecte a los humanos. Esta enfermedad ejemplifica la falta de interacción de los sectores de salud pública y veterinaria, haciendo de esta infección una de las zoonosis más frecuentes en el mundo, con especial importancia en los países mediterráneos de Europa y África, el Oriente Medio, América Central y América del Sur, Asía Central, la India y México.La brucelosis una enfermedad zoonótica causada por bacterias del género Brucella. Es un ejemplo de la falta de interacción de los sectores de salud de las ramas pública y veterinaria. Este artículo revisa las generalidades de esta enfermedad y sus antecedentes, así como la estructura celular bacteriana, la fisiopatología y las vías de contagi

Corpus cavernosum from men with vasculogenic impotence is partially resistant to adenosine relaxation due to endothelial A(2B) receptor dysfunction

ABSTRACT Although adenosine has been implicated in penile erection in human males, the receptor subtype responsible for adenosine regulation of human corpus cavernosum (HCC) smooth muscle tone is still a matter of debate. Using selective adenosine agonists and antagonists, we aimed at characterizing the adenosine receptors mediating relaxation of precontracted (with 1 M phenylephrine) HCC strips. HCC specimens were collected from control subjects (organ donors) and from patients with severe vasculogenic erectile dysfunction (ED). In control subjects, adenosine and 5 -N-ethyl-carboxamide adenosine (NECA) fully relaxed HCC. The selective A2A receptor agonist 2-[4-(2-p-carboxy ethyl)phenylamino]-5 -N-ethylcarboxamido adenosine (CGS21680C) produced only a partial relaxation (30–50%) of HCC, which could be further enhanced by simultaneous application of 100 M NECA. The selective A2B receptor antagonist N-(4-acetylphenyl)-2-[4-(2,3,6,7-tetrahydro- 2,6-dioxo-1,3-dipropyl-1H-purin-8-il)phenoxy] acetamida (MRS1706) (10 nM) attenuated NECA-induced relaxation without affecting CGS21680C action. The A2A receptor antagonist 4-{2-[7-amino-2-(2-furyl)[1,2,4]triazolo-[2,3-a][1,3,5]triazin-5- ylamino]ethyl}phenol (ZM241385) (50 nM) consistently reduced the actions of both agonists. In contrast to CGS21680C, NECAinduced relaxation was attenuated when endothelial production of NO and prostanoids was reduced by 100 M NG-nitro-Larginine and 10 M indomethacin, respectively. HCC strips from patients with vasculogenic ED were partially resistant to NECA but kept relaxation to CGS21680C; the remaining effect was sensitive to blockade of A2A receptors with 50 nM ZM241385. Data suggest that adenosine regulates HCC smooth muscle tone through the activation of two receptor populations, CGS21680C-sensitive (A2A) and -insensitive (A2B) receptors, located on smooth muscle fibers and on endothelial cells, respectively. Endothelial dysfunction may be correlated with a loss of adenosine A2B receptor activity in penile vessels from men with vasculogenic ED