Evolution of the capsular operon of Streptococcus iniae in response to vaccination.

Streptococcus iniae causes severe septicemia and meningitis in farmed fish and is also occasionally zoonotic. Vaccination against S. iniae is problematic, with frequent breakdown of protection in vaccinated fish. The major protective antigens in S. iniae are the polysaccharides of the capsule, which are essential for virulence. Capsular biosynthesis is driven and regulated by a 21-kb operon comprising up to 20 genes. In a long-term study, we have sequenced the capsular operon of strains that have been used in autogenous vaccines across Australia and compared it with the capsular operon sequences of strains subsequently isolated from infected vaccinated fish. Intriguingly, strains isolated from vaccinated fish that subsequently become infected have coding mutations that are confined to a limited number of genes in the cps operon, with the remainder of the genes in the operon remaining stable. Mutations in strains in diseased vaccinated fish occur in key genes in the capsular operon that are associated with polysaccharide configuration (cpsG) and with regulation of biosynthesis (cpsD and cpsE). This, along with high ratios of nonsynonymous to synonymous mutations within the cps genes, suggests that immune response directed predominantly against capsular polysaccharide may be driving evolution in a very specific set of genes in the operon. From these data, it may be possible to design a simple polyvalent vaccine with a greater operational life span than the current monovalent killed bacterins.

Resucitación hemostática en el paciente con choque hipovolémico hemorrágico. Reporte de un caso / Case report: Hemostatic resuscitation in the patient with hemorrhagic hypovolemic shock

In the world, traumatic pathology continues to be a problem of great magnitude, from the point of view of public health. Today, the volumemic resuscitation in hypovolemic hemorrhagic shock is still controversial; a new alternative in volemic resuscitation is the hemostatic resuscitation that consists of the rapid use of whole blood or of the administration of the concentrate of erythrocytes (CE), fresh frozen plasma (PFC) and platelet concentrate (CP), with a fixed ratio between the products. OBJECTIVE: Clinical case presentation, as well as review of the published literature on hemostatic resuscitation in patients with hemorrhagic hypovolemic shock. MATERIAL AND METHODS: We present the case of a female patient of 16 years of age with penetrating injuries in the neck, thorax and abdomen; management and evolution in the operating room, intensive care unit until discharge. RESULTS: The adequate initial resuscitation in the patient with hemorrhagic hypovolemic shock has been shown to improve their survival, so that nowadays the application of new alternatives in resuscitation; As is the hemostatic resuscitation, they have yielded better results in the patient's prognosis. CONCLUSIONS: Trauma remains one of the main causes of admission to hospital units, with the young population being the most vulnerable due to car accidents. Strategies in improving the time of transfer from the accident site to the hospital unit, its definitive management in the operating room (if required) and the use of new alternatives in the management of hemorrhagic hypovolemic shock; such as hemostatic resuscitation, and the administration of pro-hemostatic drugs, are of great importance in the evolution and prognosis of the patient.

En el mundo, la patología traumática continúa siendo un problema de gran magnitud, desde el punto de vista de salud pública. Hoy en día la resucitación volémica en el choque hemorrágico hipovolémico todavía es controversial; una nueva alternativa en la resucitación volemica es la resucitación hemostática que consiste en el uso rápido de sangre total o de la administración del concentrado de Eritrocitos (CE), Plasma Fresco Congelado (PFC) y Concentrado de Plaquetas (CP), con una razón fija entre los productos. OBJETIVO: Presentación de caso clínico, así como revisión de la literatura publicada sobre resucitación hemostática en el paciente con choque hipovolémico hemorrágico. MATERIAL Y MÉTODOS: Se presenta el caso de paciente femenino de 16 años de edad con lesiones penetrantes en cuello, tórax y abdomen; manejo y evolución en sala de operaciones, unidad de cuidados intensivos hasta su egreso. RESULTADOS: La adecuada resucitación inicial en el paciente con choque hipovolémico hemorrágico ha demostrado mejorar su sobrevida, por lo que hoy en día la aplicación de nuevas alternativas en la reanimación; como es la resucitación hemostática, han arrojado mejores resultados en el pronóstico del paciente. CONCLUSIONES: El trauma sigue siendo una de las principales causas de ingreso a las unidades hospitalarias, siendo la población joven la más vulnerable por accidentes automovilísticos. Las estrategias en la mejora del tiempo de traslado del lugar del accidente hasta la unidad hospitalaria, su manejo definitivo en sala de quirófano (si así lo requiere) y el uso de nuevas alternativas en manejo del choque hipovolémico hemorrágico; como es la resucitación hemostática, y la ministración de fármacos pro hemostáticos, resultan de gran importancia en la evolución y pronóstico del paciente.

Manejo anestésico en la enfermedad de Von Recklinghausen. Reporte de un caso / Von Recklinghausen syndrome: Case report and anesthesis management

La enfermedad de Von Recklinghausen o neurofibromatosis tipo I es una enfermedad caracterizada por tendencia a la formación de tumores de tejidos del ectodermo y mesodermo. Existen diversas implicaciones anestésicas que incluyen la sensibilidad alterada a la succinilcolina y a relajantes neuromusculares no-despolarizantes, además de alteraciones en la anatomía normal de la vía aérea; se presenta el caso de una paciente de 58 años programada para la resección de tumoración cutánea temporo-parietal derecha, se utilizó succinilcolina como relajante muscular en donde a pesar de la vida media corta de éste, no se requirió de dosis subsecuentes durante el tiempo de duración de la cirugía; por lo que se corroboro una sensibilidad alterada hacia los relajantes musculares de tipo despolarizantes en este tipo de pacientes.

Von Recklinghausen disease or neurofibromatosis type I is a disease characterized by the tendency to form tissue tumors of the ectoderm and mesoderm. There are several anesthetic implications that include altered sensitivity to succinylcholine and non-depolarizing neuromuscular relaxants, in addition to alterations in the normal anatomy of the airway; we present the case of a 58 year old patient scheduled for the resection of the right temporo-parietal cutaneous tumor. Succinylcholine was used as a muscle relaxant. Despite its short half-life, no subsequent doses were required during the treatment period duration of surgery; Therefore, an altered sensitivity towards muscle relaxants of depolarizing type was corroborated in this type of patients.

The conserved surface M-protein SiMA of Streptococcus iniae is not effective as a cross-protective vaccine against differing capsular serotypes in farmed fish.

Streptococcus iniae causes invasive infections in fresh and saltwater fish and occasional zoonoses. Vaccination against S. iniae is complicated by serotypic variation determined by capsular polysaccharide. A potential target for serologically cross-protective vaccines is the M-like protein SiMA, an essential virulence factor in S. iniae that is highly conserved amongst virulent strains. The present study determined how SiMA is regulated and investigated potential as a cross-protective vaccine for fish. Electrophoretic mobility shift suggested that SiMA is regulated by the multigene regulator Mgx via a binding site in the -35 region of the simA promoter. Moreover, expression of simA and mgx was highly correlated, with the highest level of simA and mgx expression during exponential growth under iron limitation (20-fold increase in relative expression compared to growth in Todd-Hewitt broth). Based on these results, a vaccination and challenge experiment was conducted in barramundi (Lates calcarifer) to determine whether SiMA is protective against S. iniae infection and cross-protective against a different capsular serotype. The challenge resulted in 60% mortality in control fish. Formalin-killed bacterins prepared from the challenge strain resulted in 100% protection, whereas bacterins prepared from a serotypically heterologous strain resulted in significantly reduced protection, even when culture conditions were manipulated to optimise SiMA expression. Moreover, recombinant SiMA protein was not protective against the challenge strain in spite of eliciting specific antibody response in vaccinated fish. Specific antibody did not increase oxidative activity or phagocytosis by barramundi macrophages. Indeed incubating S. iniae with antisera significantly reduced phagocytosis. Lack of specific-antibody mediated opsonisation in spite of 100% protection against challenge with the homologous vaccine suggests that other immune parameters result in protection of challenged fish.