Latex proteins downregulate inflammation and restores blood-coagulation homeostasis in acute Salmonella infection

BACKGROUND Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.

Relationship between clinical symptomatology on the isolation of Salmonella Gallinarum of japanese quail (Coturnix coturnix) / Relação entre a sintomatologia clínica no isolamento de Salmonella Gallinarum de codornas japonesas (Coturnix coturnix)

Salmonella Gallinarum is capable of causing high mortality in birds of the order Galliformes. This study aimed to relate the presence of clinical signs with the recovery of Salmonella Gallinarum from organs and c loacal swabs of Japanese quails (Coturnix coturnix) experimentally infected. A total of 70 female quails were housed in a pair per cage and divided in two groups (IG: quails inoculated with 1.5x106 CFU of Salmonella Gallinarum Nalr/mL and CG: control group). After the inoculation, birds were evaluated three times a day to verify the presence of clinical signs. Birds that presented ruffled feathers, eyes closed and remained quiet in the cage were removed for euthanasia, as well as the same number of birds from the inoculated groups that presented no clinical signs and from the control group. Cloacal swabbing was performed following euthanasia for the sampling of liver, spleen, caeca, ovarian follicles and lung for microbiological procedure. Quails with clinical signs and quails found dead presented positivity of 100%. While inoculated quails with no clinical signs presented a lower positivity (38.5%). Therefore, quails with septicemia caused by SG present clinical signs of the disease and the pathogen can be isolated and quantified in the organs.(AU)

Salmonella Gallinarum pode causar alta mortalidade em aves da ordem Galliformes. Objetivou-se neste estudo relacionar a presença de sinais clínicos com a recuperação de Salmonella Gallinarum de órgãos e swabs cloacais de codornas japonesas (Coturnix coturnix) experimentalmente infectadas. Um total de 70 codornas fêmeas foram alojadas em par por gaiola e divididas em dois grupos (IG: codornas inoculadas com 1,5x106 UFC de Salmonella Gallinarum Nalr / mL e CG: grupo controle). Após a inoculação, as aves foram avaliadas três vezes ao dia para se verificar a presença de sinais clínicos. As aves que se apresentaram com penas eriçadas, olhos fechados e permaneciam imóveis na gaiola foram removidas para a eutanásia, assim como o mesmo número de aves dos grupos inoculados que não apresentaram sinais clínicos e do grupo controle. O swab cloacal foi realizado após a eutanásia para a amostragem de fígado, baço, ceco, folículos ovarianos e pulmão para procedimento microbiológico. As codornas com sinais clínicos e as encontradas mortas apresentaram positividade de 100%, enquanto as codornas inoculadas sem sinais clínicos apresentaram menor positividade (38,5%). Portanto, codornas com septicemia causada por SG apresentam sinais clínicos da doença e o patógeno pode ser isolado e quantificado em diversos órgãos.(AU)

Salmonelose septicêmica prolongada associada à esquistossomose: evolução do conhecimento e mecanismos imunopatogênicos: [revisão] / Schistosoma-associated chronic septicemic salmonellosis: evolution of knowledge and immunopathogenic mechanisms: [review]

A salmonelose septicêmica prolongada é uma entidade clinicamente individualizada caracterizada por febre prolongada com hepatoesplenomegalia que ocorre em indivíduos esquistossomóticos coinfectados com salmonelas. Os mecanismos imunopatogênicos são vários e dependem das peculiaridades das interações entre as salmonelas e várias espécies do gênero Schistosoma. As modificações ocasionadas no sistema imunitário pela infecção parasitária são responsáveis pela evolução do quadro da doença. Nesta revisão, analisamos a evolução do conhecimento sobre a entidade e discutimos os possíveis mecanismos imunofisiopatogênicos que concorrem para seu desenvolvimento.

Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged fever with enlargement of the liver and spleen that occurs in Schistosoma-infected individuals who are coinfected with Salmonella. Several immunopathogenic mechanisms are involved, and they depend on the peculiarities of the interactions between Salmonella and various species of the genus Schistosoma. The modifications to the immune system that are caused by parasite infection are responsible for the evolution of the disease. In this review, we analyze the evolution of the knowledge on this entity and discuss the possible immuno-physiopathogenic mechanisms that contribute towards its development.

New vaccine strategies against enterotoxigenic Escherichia coli. II: enhanced systemic and secreted antibody responses against the CFA/I fimbriae by priming with DNA and boosting with a live recombinant Salmonella Vaccine

The induction of systemic (IgG) and mucosal (IgA) antibody responses against the colonization factor I antigen (CFA/I) of enterotoxigenic Escherichia coli (ETEC) was evaluated in mice primed with an intramuscularly delivered CFA/I-encoding DNA vaccine followed by two oral immunizations with a live recombinant Salmonella typhimurium vaccine strain expressing the ETEC antigen. The booster effect induced by the oral immunization was detected two weeks and one year after the administration of the DNA vaccine. The DNA-primed/Salmonella-boosted vaccination regime showed a synergistic effect on the induced CFA/I-specific systemic and secreted antibody levels which could not be attained by either immunization strategy alone. These results suggest that the combined use of DNA vaccines and recombinant Salmonella vaccine strains can be a useful immunization strategy against enteric pathogens

Genetic control of innate and acquired immunity

Host defense against infection depends on both specific and nonspecific mechanisms.The lines of mice genetically selected for high (H) or low (L) antibody responsiveness and for the maximal (AIR max.) or minimal (AIR min.) acute inflammatory response, in which the opposite extreme potentialities have been clearly defined, ofter an appropriate model for investigation of the major genetic and environmental factors of resistance to infections. The alternative advantagens of the extreme phenotypes such as efficacy of specific and nonspecific immunity in natural populations are discussed.

Intragastric infection of germfree and conventional mice with Salmonella typhimurium

The present study investigates the lethality of intragastric Salmonella typhimurium infection of germfree (GF) and conventional (CV, not germfree) mice. The introduction of only 10 viable S. typhimurium into the gastrointestinal tract of GF mice resulted in death of all animals within 8 days of inoculation. In contrast, the 50% lethal dose for CV mice was 4.7 x 10**3 viable organisms. The results demonstrate that resident microbes protect mice from the pathogenic effect of S. typhimurium infection

relation between schistosomiasis and chronic carrier state in Salmonellosis: an experimental study

Experimentally-infected mice by schistosomal cercariae were also infected by S. paratyphi A to study the inter-relationship during the various stages of development as well as the role of adult worm in producing the carrier state. Cultures of the heartblood, liver, spleen and cuticle of adult worm were done. Immunofluorescent frozen sections of liver, spleen and adult worm were performed. The results showed that whereas schistosomules are not responsible of any prolonged bacteraemia; yet, from the fourth week onwords the ingestion of host-blood leads to prolonged bacteraemia. Specific reaction to S. paratyphi A was detected on the cuticle and caeca of adult worms up to the eight week of Salmonella infection. The liver and spleen also showed non-specific fluorescent reaction. Schistosomiasis leads to prolonged bacteraemia and state of chronic S. paratyphi A carriers by exhausting the R.E.S. of the individual

Detection of Salmonella C1, D and V1 antigens, by coagglutination, in blood cultures from patients with Salmonella infections.

Protein A-containing Staphylococcus aureus was coupled to Salmonella C1, D and Vi monovalent antisera to produce C1-, D- and Vi-COAG reagents. The reagents were used to detect their homologous Salmonella antigens in blood cultures (BC). The D and Vi antigens were detected in 79 of 239 BC from patients with suspected typhoid fever and Salmonella typhi was later isolated from the same 79 BC. The C1 antigen was detected in 8 BC from which only S. oranienburg was later isolated. The COAG test was generally positive at the same time the BC became culture positive. However, because of subculture and biochemical identification requirements the COAG test could be interpreted 1-2 days before culture results were available. The COAG test can be used to presumptively identify Salmonella typhi and Salmonella group C1 in blood cultures before the culture results are available.