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Abstract: Neisseria meningitidis is the causal agent for meningitis and meningococcemia. This research was performed to phenotypically analyze invasive strains of N. meningitidis isolated in Cumana, State of Sucre. The study included all strains identified as N. meningitidis isolated in the bacteriology laboratory at the University Hospital “Antonio Patricio de Alcalá,” during the years 2009-2010, coming from cerebrospinal fluid (CSF) samples and blood cultures. For each isolate, the antimicrobial susceptibility and respective serogroup were determined. During the period of study, 10 strains were analyzed, of which 5 came from CSF. The antimicrobial susceptibility test revealed that the strains showed sensitivity to penicillin, cefotaxime, meropenem, rifampicin, ciprofloxacin and chloramphenicol; they were resistant only to trimethoprim/ sulfamethoxazole. Serogroup B was the most frequent (8 strains); one case of serogroup Y was isolated. Regarding the patient’s ages, of the 10 strains, 8 were found in pediatric patients. This is the first study about strains of N. meningitidis isolated in Cumaná, so it is essential that permanent research regarding the strains isolated in the area is carried out for monitoring purposes, mainly in terms of antimicrobial susceptibility and the circulating serogroups. Resumen: Neisseria meningitidis es agente causal de meningitis y meningococcemia. Se realizó la presente investigación a fin de analizar fenotípicamente las cepas invasivas de N. meningitidis aisladas en Cumaná, estado Sucre. Se incluyó el total de cepas identificadas como N. meningitidis en el laboratorio de bacteriología del Hospital Universitario “Antonio Patricio de Alcalá”, durante los años 2009-2010; provenientes de muestras de líquido cefalorraquídeo (LCR) y sangre (hemocultivos). A cada aislamiento se le determinó la susceptibilidad antimicrobiana y el serogrupo respectivo. Durante el período en estudio se analizaron 10 cepas, de las cuales 5 provenían de LCR. El ensayo de susceptibilidad antimicrobiana reveló que las cepas presentaban sensibilidad a penicilina, cefotaxima, meropenem, rifampicina, ciprofloxacina y cloranfenicol siendo sólo resistentes al trimetoprim/sulfametoxazol. El serogrupo más frecuente fue el B (8 cepas), aislándose un caso de serogrupo Y. Respecto al grupo etario de los pacientes, de las 10 cepas, 8 provenían de pacientes pediátricos. Este es el primer estudio con cepas de N. meningitidis aisladas en Cumaná, por lo que se hace imprescindible el análisis permanente de las cepas aisladas en la zona, con fines de monitoreo, principalmente, de la susceptibilidad antimicrobiana y los serogrupos circulantes.

It is widely recognized that periodontal disease is an inflammatory entity of infectious origin, in which the immune activation of the host leads to the destruction of the supporting tissues of the tooth. Periodontal pathogenic bacteria like Porphyromonas gingivalis , that belongs to the complex net of oral microflora, exhibits a toxicogenic potential by releasing endotoxins, which are the lipopolysaccharide component (LPS) available in the outer cell wall of Gram-negative bacteria. Endotoxins are released into the tissues causing damage after the cell is lysed. There are three well-defined regions in the LPS: one of them, the lipid A, has a lipidic nature, and the other two, the Core and the O-antigen, have a glycosidic nature, all of them with independent and synergistic functions. Lipid A is the "bioactive center" of LPS, responsible for its toxicity, and shows great variability along bacteria. In general, endotoxins have specific receptors at the cells, causing a wide immunoinflammatory response by inducing the release of pro-inflammatory cytokines and the production of matrix metalloproteinases. This response is not coordinated, favoring the dissemination of LPS through blood vessels, as well as binding mainly to Toll-like receptor 4 (TLR4) expressed in the host cells, leading to the destruction of the tissues and the detrimental effect in some systemic pathologies. Lipid A can also act as a TLRs antagonist eliciting immune deregulation. Although bacterial endotoxins have been extensively studied clinically and in a laboratory, their effects on the oral cavity and particularly on periodontium deserve special attention since they affect the connective tissue that supports the tooth, and can be linked to advanced medical conditions. This review addresses the distribution of endotoxins associated with periodontal pathogenic bacteria and its relationship with systemic diseases, as well as the effect of some therapeutic alternatives.

Here we report the biological and molecular characterization of a virulent genotype VII Newcastle disease virus (NDV) circulating in Venezuela and the assessment of the vaccination efficacy under field conditions compared to controlled rearing conditions. Biological pathotyping showed a mean embryo dead time of 50 h and an intracerebral pathogenicity index of 1.86. Sequence-based phylogenetic analysis demonstrated that the virus belongs to genotype VII in class II (a genotype often found in Asia and Africa), representing the first report of the presence of this genotype in the continent of South America. A vaccine-challenge trial in commercial broilers reared in fields or in a experimental setting included dual (live/killed) priming of 1-day-old chicks plus two live NDV and infectious bursal disease virus (IBDV) field vaccinations at days 7 and 17, followed by a very stringent genotype VII NDV challenge at day 28. Serology for NDV and IBDV, bursal integrity, and protection against NDV lethal challenge were assessed. At 28 days, field vaccinates showed significantly lower NDV (1,356 versus 2,384) and higher IBD (7,295 versus 1,489) enzyme-linked immunosorbent assay (ELISA) antibody titers than the experimentally reared birds. A lower bursal size and bursa-body weight ratio (P < 0.05) and higher bursa lesion score were also detected in the field set. Only 57.1% of field vaccinates survived the lethal challenge, differing (P < 0.05) from 90.5% survival in the experimental farm. Overall, results confirmed the presence of the genotype VII viruses in South America and suggest that field-associated factors such as immunosuppression compromise the efficacy of the vaccination protocols implemented.