Simultaneous detection of antibodies to foot-and-mouth disease non-structural proteins 3ABC, 3D, 3A and 3B by a multiplexed Luminex assay to differentiate infected from vaccinated cattle

For the first time, a multiplex bead immunoassay was used to test simultaneously, with a single sample, the immune response to foot-and-mouth disease non-structural proteins 3ABC, 3A, 3B and 3D from experimentally infected and vaccinated cattle. We cloned and expressed these non-structural proteins (NSPs) as recombinant antigens. The purified proteins were coupled to microspheres labeled with anti-His monoclonal antibody with different proportions of red and orange fluorescent dyes and reacted against serum specimens. Antibody reacting against different NSPs, and thus, the different colored beads, was detected by use of the Luminex system. This multiplex bead immunoassay can detect the immune response to NSPs in cattle as early as 7 days post-infection. In general antibodies to the protein 3D appeared early after infection and anti-3ABC antibodies were detected at higher levels than the other NSPs. A clear differentiation was established between infected and vaccinated or uninfected cattle. The multiplex bead immunoassay was compared to individual indirect enzyme-linked immunosorbent assays (iELISAs) for the same NSP's responses. Results indicated that this new assay had a high positive correlation with those generated by iELISA. The Luminex-based technology promises to be a sensitive and efficient method that permits multiplexed NSP antibody detection from a single sample and would therefore provide both a time and cost saving to the laboratory.     

Diagnóstico prenatal de una trisomía parcial del cromosoma 1 (q25-qter) por translocación paterna

We report the prenatal diagnosis of a case of partial trisomy of chromosome 1 (q25-qter) due to paternal translocation in a 31-year-old patient. Amniocentesis for chromosomal analysis was performed in the 16th week of pregnancy because ultrasound examination had revealed certain anomalies. A necropsy of the foetus was carried out and the anomalies found were compared with those in other cases of partial trisomy of chromosome 1.     

Integrating HIV Prevention Activities into the HIV Medical Care Setting: A Report from the NYC HIV Centers Consortium

With the maturing of the HIV epidemic and availability of potent antiretroviral therapies in the US, priorities for HIV prevention have shifted from general population approaches to case finding, treatment, risk reduction and relapse prevention activities among those at greatest risk for acquiring or transmitting HIV infection. The challenges of this approach include ensuring access and adherence to HIV care and treatment and appropriate prevention activities to ensure adequate and sustained sexual and drug use risk reduction across diverse populations. Experience with approaches to address these issues, particularly in the context of primary care, has been limited. An agenda for future research and practice includes continued development and evaluation of interventions that can address this next generation of health care issues. Vlahov is with the Center for Urban Epidemiologic Studies, New York Academy of Medicine, USA; Crystal is with the AIDS Research Group, Rutgers the State University of New Jersey, USA; Absalon is with the Center for Infectious Disease Epidemiologic Research, Mailman School of Public Health, Columbia University, USA; Klein and Agins are with the New York State Department of Health, AIDS Institute, USA; Remien is with the HIV Center for Clinical and Behavioral Studies, Columbia University and the NY State Psychiatric Institute, USA. An erratum to this article can be found at     

Evaluation of CrystalTM Rapid Stool/Enteric ID System for Identification of Aerobic Gram-negative Bacilli

Objective: The evaluation of the new miniaturized Crystal^TM Rapid Stool/Enteric System (Becton-Dickinson, USA) for identification of aerobic gram-negative bacilli.
Methods: a total of 154 clinical organisms ( Enterobacteriaceae: 120 strains; oxidase-positive fermenters: 13 strains; non-fermenters: 21 strains) were tested. Results were compared with those obtained with the PASCO^R system (Difco, USA) and divergent identifications were evaluated by standard biochemical tests.
Results: without additional testing, correct identification was obtained for 146 strains ( Enterobacteriaceae: 95%; oxidase-positive fermenters 87%; non-fermenters 100%). For adequate identification of Yersinia enterocolitica strains, however, panels had to be incubated for 5 instead of 3 hours.
Conclusions: the Crystal^TM Rapid Stool/Enteric system offers a safe, accurate and rapid method for the identification of frequent isolates of the family Enterobacteriaceae and bacterial stool pathogens.     

Normal host defense during systemic candidiasis in mannose receptor-deficient mice

Pathogen pattern recognition receptors (PRRs) recognize common structural and molecular motifs present on microbial surfaces and contribute to induction of innate immune responses. The mannose receptor (MR), a carbohydrate-binding receptor expressed on subsets of macrophages, is considered one such PRR. In vitro experiments have implicated the MR in phagocytosis of mannose-bearing microbes, including Candida albicans, and enhancement of antifungal response by macrophages. However, the significance of the MR's contribution to immune response during systemic C. albicans infection has never been directly demonstrated. Using MR-deficient mice in an in vivo infection experiment, we examined the role of the MR in immune response during disseminated candidiasis. MR(-/-) and wild-type control mice were challenged intraperitoneally with C. albicans, and the survival rates, tissue fungal burden, inflammatory cell recruitment, and specific antibody production after infection were evaluated. We found no significant difference in survival between the two mouse strains. MR(-/-) mice had higher average fungal burdens in some of the organs on days 7 and 21 but exhibited competence in inflammatory cell recruitment and antibody production. We also observed in vitro that MR(-/-) peritoneal cavity macrophages were equally capable of C. albicans uptake and that phagocytosis could be blocked with beta-glucan. We conclude that the MR is not required for the normal host defense during disseminated candidiasis or for the phagocytosis of C. albicans and that a beta-glucan receptor may be required for C. albicans phagocytosis.     

Comparison of a dipstick assay for detection of Brucella-specific immunoglobulin M antibodies with other tests for serodiagnosis of human brucellosis

A dipstick assay for the detection of Brucella-specific immunoglobulin M (IgM) antibodies was evaluated by studying the serological response of 133 cultures and or serologically confirmed patients with brucellosis in its different stages along with those of 34 healthy controls. As regards patients with illness less than 3 months in duration, 93.1% tested positive by the dipstick assay, a percentage similar to that obtained in the standard serum agglutination test (SAT) (92.0%), somewhat lower than that obtained by culture (100%) and higher than that obtained by IgM enzyme-linked immunosorbent assay (ELISA) (80.5%). SAT was the most sensitive test (87.0%) for patients with illness more than 3 months in duration, followed by culture (50%), the dipstick assay (28.3%), and IgM ELISA (7.5%). The results demonstrate that the dipstick assay could well be used in the serodiagnosis of patients with acute brucellosis, as well as to identify patients with a long history of the illness. Under laboratory conditions this test has the advantage of being quick and IgM antibody-specific.     

Development and use of a biotinylated 3ABC recombinant protein in a solid-phase competitive ELISA for the detection of antibodies against foot-and-mouth disease virus

A biotinylated 3ABC recombinant protein was developed and used in a competitive ELISA (cELISA) to detect foot-and-mouth disease virus (FMDV) antibodies in cattle, sheep and pigs. In this report, we describe the cloning and expression of 3ABC protein in Escherichia coli cells as fusion protein with 6xHis and biotin. This cELISA uses streptavidin to capture bacterially expressed and in vivo biotinylated 3ABC antigen. The antigen capture strategy provides a simple and reliable method, which does not require purification of recombinant antigen before the serological assay. An hyperimmune guinea pig antiserum produced against purified 6xHis-3ABC was used as competitor in the test.

The potential use of this cELISA for the identification of antibodies induced by FMD virus infection from those induced by vaccination is discussed.