RESUMO
Embora Salmonella Enteritidis (SE) seja capaz de metabolizar 1,2-propanodiol (1,2-Pd), utilizado como fonte de carbono e de energia ao longo de uma rota dependente de vitamina B12, a importância deste composto na infeção de Gallus gallus domesticus por SE permanece desconhecida. No presente estudo, foram construídos um mutante de SE sem os genes pduCDE, que codifica a propanodiol desidratase (Pdu), e outro contendo as deleções no pduCDE e também nos genes cobS e cbiA, responsáveis pela síntese de vitamina B12. Em seguida, avaliou-se a importância do metabolismo do 1,2-Pd em SE para colonização intestinal de infecção sistêmica de poedeiras comerciais. As estirpes mutantes de SE foram capazes de colonizar o intestino, de serem excretadas nas fezes e de invadir o baço e o fígado na mesma intensidade que a estirpe selvagem, o que sugere que os produtos dos genes pduC, pduD, pduE, cobS e cbiA não são essenciais durante infecção por Salmonella Enteritidis nessa espécie.(AU)
Assuntos
Animais , Salmonella enteritidis/patogenicidade , Salmonella enteritidis/ultraestrutura , Galinhas/microbiologia , Microbioma Gastrointestinal , TranscobalaminasRESUMO
BACKGROUND: In South Africa, there are no national guidelines for the conduct or quality assessment of colonoscopy, the gold standard for investigation and diagnosis of bowel pathology. OBJECTIVES: To describe the clinical profile of patients and evaluate the practice of colonoscopy using procedural quality indicators at the Wits Donald Gordon Medical Centre (WDGMC) outpatient endoscopy unit (OEU). METHODS: We conducted a prospective, clinical practice audit of colonoscopies performed on adults (≥18 years of age). A total of 1 643 patients were included in the study and variables that were collected enabled the assessment of adequacy of bowel preparation, length of withdrawal time and calculation of caecal intubation rate (CIR), polyp detection rate (PDR) and adenoma detection rate (ADR). We stratified PDR and ADR by sex, age, population group, withdrawal time and bowel preparation. CIR, PDR and ADR estimates were compared between patient groups by the χ2 test; Fisher's exact test was used for 2 × 2 tables. A p-value <0.05 was used. Benchmark recommendations by the American Society for Gastrointestinal Endoscopy (ASGE)/American College of Gastroenterology (ACG) Task Force on Colorectal Cancer (CRC) were used in this audit to assess individual endoscopist performance and that of the endoscopy unit as a whole. RESULTS: The mean age of patients was 55.7 (standard deviation (SD) 14.4; range 18 - 91) years, ~60% were female, and the majority (75.5%) were white. Of the outpatients, 77.6% had adequate bowel preparation (ASGE/ACG benchmark ≥85%). The CIR was 97.0% overall, and screening colonoscopy was 96.3% (ASGE/ACG benchmark ≥90% overall and ≥95% for screening colonoscopies). The median withdrawal time for negative-result screening colonoscopies was 5.7 minutes (interquartile range (IQR) 4.2 - 9.3; range 1.1 - 20.6) (ASGE/ACG benchmark ≥ 6minutes), and PDR and ADR were 27.6% and 15.6%, respectively (ASGE/ACG benchmark ADR ≥25%). We demonstrated a 23.7% increase in PDR and 14.1% increase in ADR between scopes that had mean withdrawal times of ≥6 minutes and <6 minutes, respectively. Although the number of black Africans in the study was relatively small, our results showed that they have similar ADRs and PDRs to the white population group, contradicting popular belief. CONCLUSIONS: The WDGMC OEU performed reasonably well against the international guidelines, despite some inadequacy in bowel preparation and lower than recommended median withdrawal times on negative-result colonoscopy. Annual auditing of clinical practice and availability of these data in the public domain will become standard of care, making this audit a baseline for longitudinal observation, assessing the impact of interventions, and contributing to the development of local guidelines.
Assuntos
Adenoma/diagnóstico , Pólipos do Colo/diagnóstico , Colonoscopia/estatística & dados numéricos , Neoplasias Colorretais/diagnóstico , Adenoma/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Assistência Ambulatorial , Benchmarking , Pólipos do Colo/epidemiologia , Colonoscopia/normas , Neoplasias Colorretais/epidemiologia , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Auditoria Médica , Pessoa de Meia-Idade , Ambulatório Hospitalar , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Indicadores de Qualidade em Assistência à Saúde , África do Sul , Adulto JovemRESUMO
INTRODUCTION: Management of perianal abscesses has remained largely unchanged for over 50 years. The evidence for postoperative wound packing is limited and may expose patients to painful procedures with no clinical benefit and at considerable increased cost. METHODS: Patients were recruited in 15 UK centres between December 2013 and October 2014. Outcome measures included number of dressing (pack) changes, healing, recurrence, return to work/normal function, postoperative fistula in ano and health utility scores (EQ-5D™). Pain was measured before, during and after dressing change on a visual analogue scale. RESULTS: Some 141 patients were recruited (median age 39 (range 18-86) years). The mean number of dressing changes in the first 3 weeks was 13 (range 0-21), equating to an annual cost to the National Health Service of 6 453 360 in England alone per annum. Some 43·8 per cent of wounds were healed by 8 weeks after surgery and 86 per cent of patients had returned to normal function. Some 7·6 per cent of abscesses had recurred and 26·7 per cent of patients developed a fistula in ano by 6 months following surgery. Patients reported a twofold to threefold increase in pain scores during and after dressing changes. CONCLUSION: Recurrent abscess is rare and fistula occurs in one-quarter of the patients. Packing is painful and costly.
Assuntos
Abscesso/terapia , Doenças do Ânus/terapia , Drenagem , Abscesso/economia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças do Ânus/economia , Bandagens/economia , Bandagens/estatística & dados numéricos , Enfermagem em Saúde Comunitária/economia , Feminino , Fissura Anal/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Recidiva , Reino Unido , Escala Visual Analógica , Cicatrização , Adulto JovemRESUMO
Lynch syndrome (LS) is an autosomal dominant cancer predisposition syndrome with a 60-80% lifetime risk of colorectal cancer. We assessed the uptake of predictive testing and colorectal screening among first-degree relatives (FDRs) in LS families and explored novel methods for informing and engaging at-risk relatives. Uptake of predictive testing was explored using Kaplan-Meier analysis and engagement with colorectal screening was ascertained. A questionnaire was distributed to 216 general practitioners (GPs) of registered LS family members to determine their prior experience and opinion of an enhanced role. Of 591, 329 (55.7%) FDRs had undergone predictive testing. Uptake was significantly lower in males (p = 0.012) and individuals <25 years (p < 0.001). Mutation carriers were more likely to undergo colorectal screening than untested FDRs (97.2% vs 34.9%; P ≤ 0.0001). Of 216, 63 (29.2%) questionnaires were returned. Most GPs (55/63; 87.3%) were not confident to discuss the details of LS with patients and relatives. The main barriers were lack of knowledge and concerns about confidentiality. Compliance with colorectal screening is excellent following a mutation positive predictive test. Uptake of predictive testing could be substantially improved, particularly among males and younger age groups. GPs are unlikely to actively participate in communication with at-risk relatives without considerable support.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , Detecção Precoce de Câncer , Testes Genéticos , Adulto , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/mortalidade , Comunicação , Reparo de Erro de Pareamento de DNA/genética , Bases de Dados Factuais , Feminino , Heterozigoto , Humanos , Estimativa de Kaplan-Meier , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Mutação , Aceitação pelo Paciente de Cuidados de Saúde , Atenção Primária à Saúde , Prognóstico , Vigilância em Saúde Pública , Risco , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: The British Society of Gastroenterology recommends that all familial adenomatous polyposis (FAP) and Lynch syndrome (LS) families are screened in the context of a registry. This systematic review was performed to appraise the published evidence for registration and screening in relation to colorectal cancer (CRC) incidence and mortality. METHODS: Five electronic databases were searched using a combination of medical subject heading terms and free-text keywords. Titles and abstracts were scrutinized by two independent reviewers. Inclusion criteria were English-language studies describing CRC incidence and/or mortality in patients with FAP or LS, with comparison of either: screened and unscreened patients, or time periods before and after establishment of the registry. RESULTS: Of 4668 abstracts identified, 185 full-text articles were selected; 43 studies fulfilled the inclusion criteria. No randomized clinical trial evidence was identified. For FAP, 33 of 33 studies described a significant reduction of CRC incidence and mortality with registration and screening. For LS, nine of ten studies described a reduction of CRC incidence and mortality with registration and screening. Five studies (FAP, 2; LS, 3) provided evidence for complete prevention of CRC-related deaths during surveillance. Clinical and statistical heterogeneity prevented pooling of data for meta-analysis. CONCLUSION: Studies consistently report that registration and screening result in a reduction of CRC incidence and mortality in patients with FAP and LS (level 2a evidence, grade B recommendation). Funding and managerial support for hereditary CRC registries should be made available.
Assuntos
Polipose Adenomatosa do Colo/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais/epidemiologia , Sistema de Registros , Polipose Adenomatosa do Colo/mortalidade , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/prevenção & controle , Neoplasias Colorretais Hereditárias sem Polipose/mortalidade , Detecção Precoce de Câncer , Saúde Global , Humanos , IncidênciaRESUMO
Urological tumours are the third most frequent malignancy in Lynch syndrome after colonic and endometrial cancer. Upper urinary tract tumours are well recognised in Lynch syndrome, but the association with prostate and bladder cancer is controversial. We determined the incidence and cumulative and relative risks of prostate and bladder cancer in a cohort of Lynch syndrome families. Male Lynch syndrome mutation carriers and their genetically untested male first degree relatives (FDR) were identified from the Manchester Regional Lynch syndrome database (n = 821). Time to the development of urological cancer was identified for each urological site (renal pelvis, ureter, bladder and prostate). Cumulative and relative risks were calculated, with results classified by mutation carrier status and specific causative genetic mutations. Eight prostate cancers were identified, only one occurring before the age of 60. Analysis of person-years at risk of prostate cancer by Lynch syndrome mutation carrier status suggests a correlation between MSH2 mutation carriers and a tenfold increased risk of prostate cancer (RR 10.41; 95 % CI 2.80, 26.65). No such association was found with bladder cancer (RR 1.88; 95 % CI 0.21, 6.79). The association of upper urinary tract tumours with MSH2 and MLH1 mutations was confirmed. We have carried out the largest study of male Lynch syndrome mutation carriers to establish the risks of urological malignancy. A tenfold increased risk of prostate cancer is supported in MSH2 with mutation carriers having roughly double the risk of prostate cancer to FDRs. A trial of PSA testing in MSH2 carriers from 40 to 50 years may be justifiable.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Urológicas/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Neoplasias Colorretais/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Predisposição Genética para Doença , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Análise de Sobrevida , Neoplasias Urológicas/genética , Adulto JovemRESUMO
Salmonella enterica subspecies enterica infection remains a serious problem in a wide range of animals and in man. Poultry-derived food is the main source of human infection with the non-host-adapted serovars while fowl typhoid and pullorum disease are important diseases of poultry. We have assessed cecal colonization and immune responses of newly hatched and older chickens to Salmonella serotypes Enteritidis, Infantis, Gallinarum and Pullorum. S. Enteritidis and S. Infantis colonized the ceca more efficiently than S. Gallinarum and S. Pullorum. Salmonella infection was also associated with increased staining for B-lymphocytes and macrophages in the cecal tonsils of infected birds. S. Enteritidis infection in newly hatched birds stimulated the expression of CXCLi1 and CXCLi2 chemokines in the cecal tonsils, while S. Gallinarum up-regulated the expression of LITAF. In older chickens, S. Enteritidis infection resulted in a significantly higher expression of CXCLi2, iNOS, LITAF and IL-10 while S. Pullorum appeared to down-regulate CXCLi1 expression in the cecal tonsils. Data from spleens showed either no expression or down-regulation of the tested genes.
Assuntos
Ceco/microbiologia , Interações Hospedeiro-Patógeno , Tonsila Palatina/imunologia , Salmonelose Animal/imunologia , Salmonella enterica/imunologia , Transcriptoma , Animais , Linfócitos B/imunologia , Linfócitos B/microbiologia , Carga Bacteriana , Ceco/imunologia , Ceco/patologia , Quimiocina CXCL1/genética , Quimiocina CXCL1/imunologia , Quimiocina CXCL2/genética , Quimiocina CXCL2/imunologia , Galinhas/imunologia , Galinhas/microbiologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Imuno-Histoquímica , Interleucina-10/genética , Interleucina-10/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Tonsila Palatina/microbiologia , Tonsila Palatina/patologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/patogenicidadeRESUMO
There is increasing evidence that activation of innate immunity, in animals and man, by live vaccines, sub-unit vaccines or synthetic or non-synthetic stimulants can induce a profound and rapidly induced resistance to pathogens, including infectious agents that are unrelated to the stimulating antigen or agent. We review the evidence for this phenomenon and present the proposition that this approach might be used to stimulate immunity during the life of the animal when susceptibility to infection is high and when normal vaccination procedures may be inappropriate.
Assuntos
Emergências/veterinária , Imunidade Inata , Infecções/terapia , Vacinação/veterinária , Animais , Citocinas/uso terapêutico , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Infecções/imunologia , Infecções/microbiologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Receptores Toll-Like/agonistasRESUMO
In this study, the effect of lipopolysaccharide (LPS) on protein synthesis (PS) and intracellular signaling factors that regulate it have been investigated in C2C12 murine-derived myotubes. In particular, the role of Akt/mammalian target of rapamycin (mTOR) and the mitogen-activated protein kinases (MAPKs) [p38 and extracelluar regulated protein kinase (ERK1/2)] have been examined. The direct effect of LPS on PS was measured at 3 and 18 h. LPS significantly decreased PS at 3 h but not at the 18-h time point. This effect was preceded by decreased Akt phosphorylation at 5 and 30 min after LPS administration. The mTOR phosphorylation exhibited a long time dose-dependent increase at all the time points. Similarly, the activity-related phosphorylation of p38 and ERK1/2 significantly increased in a time- and dose-dependent manner at all the time points. Polymyxin B abolished the LPS-induced decrease in PS rate. The phosphatidylinositol 3-kinase inhibitor LY-0294002 in combination with LPS significantly decreased the rate of PS by 81% and alone by 66%, respectively, for the 3- and 18-h time points, whereas p38 and ERK inhibitors in combination with LPS significantly decreased the rate PS rate at the 18-h time point by 41% and 59%, respectively, compared with control cells. In conclusion, LPS alone transiently decreased the rate of PS by 50% at 3 h; this effect is most likely mediated via the Toll-like receptor 4 (TLR4)-Akt/mTOR pathway, and both p38 and ERK when inhibited in the presence of LPS at 3 h have a similar effect in preventing the LPS-induced reduction in PS.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Proteínas Musculares/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Lipopolissacarídeos/administração & dosagem , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Fibras Musculares Esqueléticas/efeitos dos fármacos , Proteínas Musculares/genética , Mioblastos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de TempoRESUMO
Salmonella enterica serovar Gallinarum (SG) is an intracellular pathogen of chickens. To survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. The fumarate reductase (frdABCD), dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. In this study mortality rates of chickens challenged with mutants of Salmonella Gallinarum, which were defective in utilising anaerobic electron acceptors, were assessed in comparison to group of bird challenged with wild strain. The greatest degree of attenuation was observed with mutations affecting nitrate reductase (napA, narG) with additional attenuations induced by a mutation affecting fumarate reductase (frdA) and a double mutant (dmsA torC) affecting DMSO and TMAO reductase.
Assuntos
Animais , Bactérias Anaeróbias/genética , Ativação Enzimática , Genes Bacterianos , Mutação , Aves Domésticas , Infecções por Salmonella , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Ensaios Enzimáticos Clínicos , Métodos , Métodos , VirulênciaRESUMO
Since the late 1970s a number of laboratories have studied the role of vasoactive intestinal peptide (VIP) in inflammation and immunity. These studies have highlighted the dramatic effect of VIP on immune cell activation and function, and studies using animal models of disease have indicated that VIP has significant therapeutic and prophylactic potential. This review will focus on the effects of VIP on innate immune cell function and discuss the therapeutic potential for VIP in inflammatory diseases of humans.
Assuntos
Doenças do Sistema Imunitário/imunologia , Peptídeo Intestinal Vasoativo/fisiologia , Citocinas/imunologia , Células Dendríticas/imunologia , Humanos , Doenças do Sistema Imunitário/tratamento farmacológico , Doenças do Sistema Imunitário/metabolismo , Imunidade Inata , Mediadores da Inflamação/metabolismo , Receptores de Peptídeo Intestinal Vasoativo/metabolismo , Receptores Toll-Like/metabolismo , Peptídeo Intestinal Vasoativo/uso terapêuticoRESUMO
Vasoactive intestinal peptide is an immunomodulator with great potential in the treatment of inflammatory pathology. In this study, we have examined the effect of VIP on the growth dynamics of virulent Salmonella enterica. Serovar typhimurium (S. typhimurium) 14028 and 4/74 and an avirulent mutant (14028 phoP) in a murine, macrophage cell line (J774.2). In contrast to standard growth dynamics, in which phoP mutants do not survive in macrophages, we show that VIP (10(-10) M) significantly enhances phoP growth over a 24 h post-infection period even when the cells are co-cultured with IFN-gamma. We examined the effect of VIP on the generation of NADPH-induced reactive oxygen species (ROS) in Salmonella-infected/IFN-gamma cultured J774 cells. VIP inhibited gp91 mRNA levels, gp91 protein and subsequent ROS. The importance of ROS in killing of Salmonella by J774 cells was highlighted by experiments in which ROS production by J774 cells was inhibited using a conventional inhibitor, N-acetyl-L-cysteine captopril (ACC) and in which Salmonella growth significantly increased. Our findings suggest that although VIP inhibits inflammatory pathways in myeloid cells it also promotes the growth of avirulent (phoP) mutants.
Assuntos
Interferon gama/farmacologia , Macrófagos/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , NADPH Oxidases/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Peptídeo Intestinal Vasoativo/farmacologia , Animais , Proteínas de Bactérias/genética , Captopril/análogos & derivados , Captopril/farmacologia , Linhagem Celular , Expressão Gênica/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/microbiologia , Glicoproteínas de Membrana/genética , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Mutação , NADPH Oxidase 2 , NADPH Oxidases/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salmonella typhimurium/genéticaRESUMO
The effect of gamma interferon (IFN-gamma) on elevation of reactive oxygen species and the viability of virulent wild-type and avirulent mutants of Salmonella enterica serovar Typhimurium and S. enterica serovar Infantis was studied in a murine macrophage cell line (J774.2 cells). S. enterica serovar Typhimurium 14028 phoP and a rough lipopolysaccharide mutant of S. enterica serovar Infantis 1326/28 (phi(r)) (avirulent mutants) induced NADPH phagocytic oxidase gp91 (gp91(phox)) activity and a significant (P < 0.05) elevation of reactive oxygen species within 12 h without coculture with IFN-gamma. This coincided with reduced survival of S. enterica serovar Typhimurium14028 phoP or stasis of S. enterica serovar Infantis phi(r). Fluorometric studies indicated that expression of IFN-gamma on infected J774.2 cells was not significantly (P > 0.05) elevated. However, studies with the virulent S. enterica serovar Typhimurium strains showed that a comparable level of control of bacterial numbers could only be achieved by coculture with IFN-gamma. This coincided with significant upregulation of IFN-gamma receptor alpha expression on the surface of J774.2 cells and was completely abolished by N-acetyl-L-cysteine captopril (an inhibitor of reactive oxygen species). Delay in reactive oxygen species induction due to a requirement for IFN-gamma and upregulation of IFN-gamma receptor alpha in macrophages infected with virulent salmonellae may result in greater dissemination of virulent salmonellae in host tissue.
Assuntos
Interferon gama/farmacologia , Macrófagos/imunologia , Macrófagos/microbiologia , Glicoproteínas de Membrana/metabolismo , NADPH Oxidases/metabolismo , Receptores de Interferon/genética , Salmonella/imunologia , Salmonella/patogenicidade , Animais , Captopril/análogos & derivados , Captopril/farmacologia , Linhagem Celular , Peróxido de Hidrogênio/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , NADPH Oxidase 2 , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes , Explosão Respiratória , Salmonella/genética , Salmonella/fisiologia , Salmonella enterica/genética , Salmonella enterica/imunologia , Salmonella enterica/patogenicidade , Salmonella enterica/fisiologia , Salmonella typhimurium/genética , Salmonella typhimurium/imunologia , Salmonella typhimurium/patogenicidade , Salmonella typhimurium/fisiologia , Regulação para Cima , Virulência/genética , Receptor de Interferon gamaRESUMO
We investigated the attenuating effects of a range of respiratory chain mutations in three Salmonella serovars which might be used in the development of live vaccines. We tested mutations in nuoG, cydA, cyoA, atpB, and atpH in three serovars of Salmonella enterica: Typhimurium, Dublin, and Gallinarum. All three serovars were assessed for attenuation in their relevant virulence assays of typhoid-like infections. Serovar Typhimurium was assessed in 1-day-old chickens and the mouse. Serovar Gallinarum 9 was assessed in 3-week-old chickens, and serovar Dublin was assessed in 6-week-old mice. Our data show variation in attenuation for the nuoG, cydA, and cyoA mutations within the different serovar-host combinations. However, mutations in atpB and atpH were highly attenuating for all three serovars in the various virulence assays. Further investigation of the mutations in the atp operon showed that the bacteria were less invasive in vivo, showing reduced in vitro survival within phagocytic cells and reduced acid tolerance. We present data showing that this reduced acid tolerance is due to an inability to adapt to conditions rather than a general sensitivity to reduced pH. The data support the targeting of respiratory components for the production of live vaccines and suggest that mutations in the atp operon provide suitable candidates for broad-spectrum attenuation of a range of Salmonella serovars.
Assuntos
Proteínas de Bactérias/fisiologia , Citocromos/fisiologia , Complexo de Proteínas da Cadeia de Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/fisiologia , Transporte de Elétrons , Proteínas de Escherichia coli , NADH NADPH Oxirredutases/fisiologia , Oxirredutases/fisiologia , ATPases Translocadoras de Prótons/fisiologia , Salmonella typhimurium/patogenicidade , Animais , Linhagem Celular , Galinhas , Grupo dos Citocromos b , Complexo I de Transporte de Elétrons , Feminino , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Óperon , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Sorotipagem , VirulênciaRESUMO
Salmonella enterica serovar Pullorum is worldwide a poultry pathogen of considerable economic importance, particularly in those countries with a developing poultry industry. In addition to the characteristic high mortality rates among young chicks, one of the features of Salmonella serovar Pullorum infection is that it persists for long periods in convalescent chicks in the absence of clinical disease. This can lead to colonization of the reproductive tract of chickens and at sexual maturity can result in infected progeny through transovarian transmission to eggs. The sites of Salmonella serovar Pullorum persistence in convalescent birds are not known, and the mechanisms of persistence are not understood. Here we show that Salmonella serovar Pullorum can persist in both the spleen and the reproductive tract for over 40 weeks following experimental infection in chickens. During the period of sexual maturity, Salmonella serovar Pullorum colonized both the ovary and the oviduct of hens and led to 6% of laid eggs being infected by Salmonella serovar Pullorum. The colonization of several different sites of the reproductive tract suggests that Salmonella serovar Pullorum may employ more than one mechanism of egg infection. Persistence occurred despite a strong humoral response, suggesting an intracellular site of infection. By use of a Salmonella serovar Pullorum strain containing a plasmid stably expressing green fluorescent protein, we demonstrated that the main site of carriage in the spleen is within macrophages. This raises interesting questions about the biology of Salmonella serovar Pullorum, including why there is an increase in bacterial numbers when birds become sexually mature and in particular how Salmonella serovar Pullorum avoids clearance by macrophages and whether it modulates the immune system in other ways.
Assuntos
Portador Sadio/microbiologia , Galinhas , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/isolamento & purificação , Baço/microbiologia , Animais , Anticorpos Antibacterianos/sangue , Especificidade de Anticorpos , Contagem de Colônia Microbiana , Convalescença , Feminino , Imunoglobulina G/imunologia , Transmissão Vertical de Doenças Infecciosas , Macrófagos/microbiologia , Doenças das Aves Domésticas/transmissão , Salmonelose Animal/transmissão , Baço/citologiaRESUMO
Salmonella enterica serovar Gallinarum is a host-specific serotype that causes the severe systemic disease fowl typhoid in domestic poultry and a narrow range of other avian species but rarely causes disease in mammalian hosts. Specificity of the disease is primarily at the level of the reticuloendothelial system, but few virulence factors have been described other than the requirement for an 85-kb virulence plasmid. In this work, by making functional mutations in the type III secretion systems (TTSS) encoded by Salmonella pathogenicity island 1 (SPI-1) and SPI-2, we investigated the role of these pathogenicity islands in interactions between Salmonella serovar Gallinarum and avian cells in vitro and the role of these pathogenicity islands in virulence in chickens. The SPI-1 mutant showed decreased invasiveness into avian cells in vitro but was unaffected in its ability to persist within chicken macrophages. In contrast the SPI-2 mutant was fully invasive in nonphagocytic cells but failed to persist in macrophages. In chicken infections the SPI-2 mutant was attenuated while the SPI-1 mutant showed full virulence. In oral infections the SPI-2 mutant was not observed in the spleen or liver, and following intravenous inoculation it was cleared rapidly from these sites. SPI-2 function is required by Salmonella serovar Gallinarum for virulence, primarily through promoting survival within macrophages allowing multiplication within the reticuloendothelial system, but this does not preclude the involvement of SPI-2 in uptake from the gut to the spleen and liver. SPI-1 appears to have little effect on virulence and survival of Salmonella serovar Gallinarum in the host.
Assuntos
Proteínas de Bactérias/metabolismo , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/patogenicidade , Animais , Proteínas de Bactérias/genética , Células Cultivadas , Galinhas , Macrófagos/microbiologia , Mutação , Salmonella enterica/fisiologia , Virulência/genéticaRESUMO
Clear genetic differences in the susceptibility of chickens to visceral infection by Salmonella have been observed and it has been possible to identify resistant and susceptible lines of inbred chickens. We report here the results of experiments to map directly the gene(s) controlling this trait in chickens by examining crosses between highly susceptible and highly resistant lines. In the mapping panel, a region on chicken Chromosome (Chr) 5 was found to have a large effect on resistance, and this effect was observed in three separate resource populations. Mapping of additional marker loci in the region of the resistance gene further localized it to a region of approximately 2 cM, close to the genes for creatine kinase (CKB) and dynein (DNCH1). This region shows conserved synteny with telomeric regions of human Chr 14 and mouse Chr 12. On the basis of this conserved synteny, this resistance gene seems unlikely to correspond to the previously identified salmonellosis resistance genes Lps (located on mouse Chr 4) or Nos(2) (located on mouse Chr 11). There was no association between Nramp1 and resistance in these crosses, although this gene was shown to contribute to resistance in other crosses. The homologous human and mouse regions at present contain no likely candidate genes for this trait. Thus this appears to be a novel resistance gene, which we designate SAL1.
Assuntos
Galinhas/genética , Galinhas/imunologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/imunologia , Salmonelose Animal/genética , Salmonelose Animal/imunologia , Animais , Proteínas de Transporte de Cátions/genética , Mapeamento Cromossômico , Creatina Quinase/genética , Cruzamentos Genéticos , Dineínas/genética , Ligação Genética , Marcadores Genéticos , Humanos , Camundongos , Especificidade da EspécieRESUMO
Twenty-four-hour-old, aerobically grown, Luria-Bertani broth cultures of Salmonella typhimurium F98 suppressed the growth of a spectinomycin-resistant (Spcr) derivative of the same strain inoculated at 10(3) CFU ml(-1). This growth suppression is genus specific and RpoS independent, and it is not solely a result of nutrient depletion (P. A. Barrow, M. A. Lovell, and L. Zhang-Barber, J. Bacteriol. 178:3072-3076, 1996). Mutations in three genes are shown here to significantly reduce growth suppression under these conditions. The mutations were located in the nuo, cyd, and unc operons, which code for the NADH dehydrogenase I, cytochrome d oxidase, and F0F1 proton-translocating ATPase complexes, respectively. When cultures were grown under strictly anaerobic conditions, only the unc mutant did not suppress growth. Prior colonization of the alimentary tract of newly hatched chickens with the S. typhimurium F98 wild type or nuo or cyd mutants suppressed colonization by an S. typhimurium F98 Spcr derivative inoculated 24 h later. In contrast, the S. typhimurium unc mutant did not suppress colonization. The nuo and unc mutants showed poorer growth on certain carbon sources. The data support the hypothesis that growth suppression operates because of the absence of a utilizable carbon source or electron acceptor.
Assuntos
Citocromos/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons , Proteínas de Escherichia coli , NADH Desidrogenase/genética , Oxirredutases/genética , ATPases Translocadoras de Prótons/genética , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/genética , Anaerobiose , Animais , Bioensaio , Galinhas , Clonagem Molecular , Grupo dos Citocromos b , Citocromos/metabolismo , DNA Bacteriano/genética , Dados de Sequência Molecular , Mutagênese Insercional , NADH Desidrogenase/metabolismo , Óperon , Oxirredutases/metabolismo , Reação em Cadeia da Polimerase , ATPases Translocadoras de Prótons/metabolismo , Salmonella typhimurium/metabolismoRESUMO
Pamiteplase (genetical recombination), YM866, is a novel recombinant modified human tissue-type plasminogen activator developed by Yamanouchi Pharmaceutical Co. Ltd., Tokyo, Japan. An intended route of administration in the clinical use of this drug is intravenous administration. We conducted an intravenous fertility and general reproduction studies of this drug in male and female rats and teratology study of this drug in rabbits at the dose levels of 0 (vehicle control), 0.1, 0.3 or 1 mg/kg/day. In the rat, no treatment-related abnormalities were observed up to the maximum dose in parental animals and their offspring. In the teratology study in rabbits, prolonged coagulation time at the injection site was observed at 0.3 mg/kg or more. One death and one abortion occurred at 1 mg/kg on days 22 and 23 of pregnancy, respectively. No toxic effects on the litters were observed up to the maximum dose. Results of evaluation of the mutagenicity of YM866 and its ability to induce chromosome aberrations using the L5178Y TK+/- mouse lymphoma assay, human lymphocyte chromosome aberration assay and the micronucleus assay in mice were negative. Evaluation of the immunogenicity of YM866 by repeated intravenous injection in chimpanzees elicited no confirmed antibody titers.