RESUMO
Streptococcus zooepidemicus is an emerging zoonotic pathogen involved in septicemic infections in humans and livestock. Raising guinea pigs in South America is an important economic activity compared to raising them as pets in other countries. An outbreak of severe lymphadenitis was reported in guinea pigs from farms in the Andean region. S. zooepidemicus was isolated from multiple cervical and mandibular abscesses. Isolate was characterized by multilocus sequence typing and phylogenetic analysis. This is the first molecular characterization of a highly pathogenic strain, showing major important virulence factors such as the M-like protein genes szP and mlpZ, the fimbrial subunit protein gene fszF, and the protective antigen-like protein gene spaZ. Additionally, this guinea pig strain was phylogenetically related to equines but distant from zoonotic and pig isolates reported in other countries.
RESUMO
Cystic echinococcosis (CE) is a parasitic zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. Detection of the adult stage in the canine definitive host is essential for estimating infection rates, surveillance and monitoring of CE control programs. This study sought to develop and validate a coproantigen sandwich enzyme-linked immunosorbent assay (copro-ELISA), based on antibodies against E. granulosus-soluble membrane antigens (EGMA), that is capable of distinguishing infected and noninfected dogs. Anti-E. granulosus polyclonal immunoglobulin G antibodies were obtained from rabbit antiserum against EGMA. Optimization of the test was performed with 51 positive and 56 negative stool samples of canine echinococcosis. Specificity, sensitivity, cross-reactivity, intra- and inter-assay precision, and over time detection were evaluated. According to the receiver operating characteristic analysis, the diagnostic sensitivity and specificity were 96.1% (CI: 85.9-99.6) and 98.2% (CI: 89.5-100), respectively. Negative and positive predictive values were 96.5% (CI: 91.7-100) and 98% (CI: 94.1-100), respectively. No cross-reactivity with Taenia hydatigena, Dipylidium caninum, or Toxocara canis was observed. Intra- and inter-assay repeatability showed values of less than 15% of the variation coefficient. The over time detection was from 20 to 27 days postinfection with E. granulosus. The copro-ELISA based on EGMA detection offers a simplified in-house development of diagnostic testing. This assay showed high specificity and sensitivity and had no cross-reactivity with other parasites. Further studies and development of this test in a kit format may be useful for the detection of active infection in dogs living in CE endemic regions.
Assuntos
Anticorpos Anti-Helmínticos/química , Antígenos de Helmintos/análise , Doenças do Cão/diagnóstico , Equinococose/diagnóstico , Equinococose/veterinária , Echinococcus granulosus/imunologia , Ensaio de Imunoadsorção Enzimática/normas , Animais , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Equinococose/epidemiologia , Equinococose/imunologia , Echinococcus granulosus/isolamento & purificação , Fezes/parasitologia , Humanos , Larva/imunologia , Variações Dependentes do Observador , Peru/epidemiologia , Coelhos , Sensibilidade e EspecificidadeRESUMO
The objective of this study was to compare the ability of two commercial enzyme-linked immunosorbent assays (ELISAs) and an in-house fluorescent microbead immunoassay (FMIA) to detect IgG antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) types 1 and 2 in serum and oral fluids from boars infected experimentally. Samples from uninfected control pigs and PRRSV-negative field samples were also used. Serum samples were tested by ELISAs (IDEXX Se, HIPRA Se) and an in-house FMIA-Se for detection of PRRSV types 1 and 2. Oral fluids were tested by ELISAs (IDEXX-SO, IDEXX-OF, HIPRA-OF) for detection of PRRSV types 1 and 2. Among the sera, IDEXX-Se and HIPRA-Se had similar sensitivity and specificity (p>0.05); however, IDEXX-Se detected positive animals earlier than HIPRA-Se (p<0.05). FMIA-Se had the highest false-positive rates in known negative field samples (1/205 for IDEXX-Se, 5/205 for HIPRA-Se, and 37/205 for FMIA-Se; p<0.01). Serum and oral fluid samples had similar detection rates and antibody kinetics using the IDEXX tests. There was a higher detection rate in serum than oral fluid using the HIPRA assays. In this study, the nucleocapsid protein utilized as antigen in the FMIAs yielded a low specificity. IDEXX-Se had the earliest detection and similar sensitivity and specificity to the HIPRA-Se.