ABSTRACT
BACKGROUND: External root resorption (ERR) has a multifactorial etiology and is difficult to diagnose, which means that is continues to be of research interest. This work mainly aims to determine whether external root resorption can be differentially detected in root-filled versus non-endodontically treated teeth using digital periapical radiography (DPR) and cone-beam computed tomography (CBCT). METHODS: The Checklist for Reporting In-vitro Studies (CRIS) guidelines were followed throughout this study. This experiment highlights the preparation and generation of standardized synthetic teeth measured on three-dimensional records converted into Digital Imaging and Communication on Medicine (DICOM) file format. Twelve replicate maxillary incisors were randomized into two groups: (G1) six non-endodontically treated, and (G2) six endodontically treated teeth. In both groups, actual tooth lengths of all specimens were measured and compared with measurements obtained using DPR and CBCT. Simulated ERR lesions [0.12, 0.18, 0.20 mm × 0.5 mm depth in the mesial, distal and palatal apical regions] were created progressively, radiographic images were recorded, and 24 DPRs and 96 CBCTs were obtained in total. Eight blinded, previously calibrated researchers made a total of 1920 measurements (using Horos Software). Data were analyzed using the Shapiro-Wilk, ANOVA, Kruskal-Wallis and Wilcoxon rank post-hoc tests [Bonferroni correction in multiple comparison tests (p < 0.05)]. RESULTS: ICC values for intra- and inter-examiner agreement were appropriate. DPR overestimated ERR detection compared to the actual and CBCT measurements [Mean diff = 0.765 and 0.768, respectively]. CBCT diagnosis of ERR lesions in specimens without root canal treatment was significantly more accurate than DPR diagnoses on both non-endodontically and endodontically-treated specimens [p = 0.044; p = 0.037, respectively]. There was an 18.5% reduction in sensitivity in all DPR diagnoses made on endodontic teeth versus those made on non-endodontically treated teeth. For the smallest ERR lesions, this sensitivity was even more marked, with 27.8 and 25% less sensitivity, respectively. CONCLUSIONS: The results of this study highlight that both CBCT and DPR are good diagnostic methods for ERR. Nevertheless, root canal filling material influences diagnostic capability in ERR. The clinical significance was that the presence of intracanal material reduces the detection and diagnosis of ERR by DPR in teeth with root canal treatment.
Subject(s)
Root Canal Filling Materials , Root Resorption , Humans , Cone-Beam Computed Tomography/methods , Radiography, Dental, Digital/methods , Root Canal Filling Materials/therapeutic use , Root Canal Therapy/methods , Root Resorption/diagnostic imaging , Incisor/diagnostic imagingABSTRACT
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)
Subject(s)
Animals , Salmonella enteritidis/pathogenicity , Salmonella enteritidis/ultrastructure , Chickens/microbiology , Gastrointestinal Microbiome , TranscobalaminsABSTRACT
Detection and analysis of virulence-associated genes (VAGs) of avian pathogenic Escherichia coli (APEC) may be helpful to distinguish pathogenic from commensal faecal strains (AFEC). The aim of this study was to characterise 120 isolates of avian Escherichia coli, comprising 91 APEC (from diseased birds) and 29 AFEC (from healthy chickens), collected in Brazil. Phylogenetic analysis and in vivo pathogenicity testing was performed on 38 VAGs. The VAGs iucD, iutA, iroN, fepC, ompT, cvi and hlyF were statistically associated with medium and high pathogenicity (MP/HP) strains. A minimal group of seven VAGs may be required to accurately discriminate pathogenic and non-pathogenic avian strains of E. coli in Brazil.
Subject(s)
Chickens , Escherichia coli Infections/veterinary , Escherichia coli/physiology , Escherichia coli/pathogenicity , Genes, Bacterial , Poultry Diseases/microbiology , Animals , Brazil , Escherichia coli/genetics , Escherichia coli Infections/microbiology , Feces/microbiology , Phylogeny , Sequence Analysis, DNA/veterinary , VirulenceABSTRACT
New vaccine design techniques have allowed the development of effective vaccine strains against Salmonella infections inwhich the risks of reversion to the wild type and virulence is null. The mutant strain Salmonella Gallinarum ΔcobSΔcbiA was previously shown to be avirulent in chickens. In this study, this strain was tested as a vaccine against Salmonella Gallinarum (SG) and S. Enteritidis (SE) infections, and its protection levels, safety and possible risks of reversion to virulence after vaccination of layers were evaluated. Birds were vaccinated at five days of age or at five and 25 days of age. At 45 days of age, brown and white layers were challenged with SG and SE wild strains, respectively. Two assays to test the possibility of reversion to virulence were performed. Five successive bacterial passages in brown layers were carried out in the first assay. In the second assay, brown layers received a ten-fold concentrated inoculum of the SGΔcobSΔcbiA strain and were evaluated for clinical signs and mortality. In both experiments, no birds that received the inoculation of the attenuated strain died. Additionally, the use of the mutant strain as a vaccine provided good protection levels against both challenge strains.(AU)
Subject(s)
Animals , Poultry Diseases/immunology , Salmonella Infections/prevention & control , Chickens/microbiology , Salmonella Vaccines/pharmacology , Salmonella/immunology , Virulence FactorsABSTRACT
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.
Subject(s)
Animals , Bacteria, Anaerobic/genetics , Enzyme Activation , Genes, Bacterial , Mutation , Poultry , Salmonella Infections , Salmonella enterica/genetics , Salmonella enterica/isolation & purification , Clinical Enzyme Tests , Methods , Methods , VirulenceABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Young poultry are very susceptible to Salmonella Enteritidis (SE) infections because of the absence of complete intestinal flora colonization and an immature immune system. This study evaluated the role of passive immunity on the resistance of young birds against early infections caused by SE. The progeny of broiler breeders vaccinated with an oil-emulsion bacterin was compared to the progeny of unvaccinated birds. Efficacy was determined by challenging birds at 1 and 14 days of age with SE Nal Spc strain, phage type 4. After challenge at 1 day of age, the progeny of vaccinated birds presented a significantly lower number (log10) of SE Nal Spc reisolation (P < 0.05) in liver (2.21), spleen (2.31), and cecal contents (2.85) compared with control groups (2.76, 3.02, and 6.03, respectively). The examination of the internal organs, 3 days after infection, revealed that 28% of the birds (7/25) from vaccinated breeders were positive, whereas 100% (25/25) of the chicks derived from unvaccinated birds were positive. Birds challenged at 14 days of age presented a lower number of positive samples compared with those challenged at 1 day of age, and the progeny of vaccinated birds presented statistically lower numbers (log10) of colony-forming units/ml of SE Nal Spc only in the cecal contents compared with nonvaccinated breeder progeny (2.11 vs. 2.94). Age seems to influence the susceptibility of birds to SE infections: in control groups, the number of positive birds at 14 days of age (9/25) was lower when compared with the group infected at 1 day of age (25/25). The number of positive fecal samples of the progeny of vaccinated birds was significantly lower (36) than those of the control group (108) after challenge at 1 day of age. Unchallenged progeny of vaccinated birds presented passive antibodies detectable by enzyme-linked immunosorbent assay (ELISA) up to 21 days of age. On the other hand, antibodies of the control group were detected by ELISA 14 days after challenge. These results show a significant contribution of breeder vaccination by increasing the resistance of the progeny against early SE infections. However, the bacteria were not completely eliminated, suggesting that additional procedures are needed to effectively control SE infections.
Subject(s)
Chickens , Immunity, Maternally-Acquired , Poultry Diseases/immunology , Salmonella Infections, Animal/immunology , Salmonella Vaccines/immunology , Salmonella enteritidis/immunology , Animals , Antibodies, Bacterial/blood , Poultry Diseases/microbiology , Salmonella Infections, Animal/microbiology , Time FactorsABSTRACT
BACKGROUND: Salmonellosis is a common problem worldwide in commercially reared poultry. It is associated with human Salmonellosis. No fully satisfactory method of control is available. METHOD: Nosodes to an antibiotic-resistant strain of Salmonella enterica serovar Enteritidis in D30 (30X) potency were prepared. One day old chicks (N = 180) were divided into four groups: two control and two different preparations of the nosode. Treatments were administered in drinking water for 10 days. The birds were challenged by a broth culture of the same Salmonella, by mouth, on day 17. Cloacal swabs were taken twice weekly for Salmonella enterica serovar Enteritidis. RESULTS: Birds receiving active treatment were less likely to grow the strain of Salmonella from cloacal swabs compared to control. CONCLUSION: Isopathy is low cost and non-toxic. It may have a role to play in the widespread problem of Salmonella in poultry. Further research should be conducted.
Subject(s)
Chickens , Homeopathy/methods , Materia Medica/therapeutic use , Poultry Diseases/drug therapy , Salmonella Infections, Animal/drug therapy , Salmonella enteritidis , Administration, Oral , Animals , Chi-Square Distribution , Poultry Diseases/microbiology , Salmonella Infections, Animal/microbiology , Treatment OutcomeABSTRACT
ABSTRACT This work was carried out to assess the preenrichment (PE) and enrichment (DE) steps for isolating Salmonella serotypes Enteritidis (SE) and Typhimurium (STM) from chicken feces kept at 4° C for 24 and 96h. The samples were artificially contaminated and kept in 1% peptone water at 4° C for 24 or 96h. After that, part of them was incubated at 37° C/24h and part was inoculated into enrichment broth, selenite broth plus novobiocin (SN) and tetrathionate broth plus novobiocin (TN) incubated at 37°C/24h. The PE culture was inoculated in SN, TN and Rapapport-Vassiliadis novobiocin (RVN), also incubated at 37° C/24h. The enrichment broth was plated on brilliant green agar (BGA), MacConkey agar (MCA), Hektoen agar (HEA), Salmonella-Shigella agar (SSA), xylose-lysine desoxicholate agar (XLDA) and xylose-lysine tergitol 4 (XLT4), which were incubated at 37° C/24h. Salmonella-like colonies were submitted to TSI agar and LIA agar, and incubated at 37° C/24h, as well as to slide agglutination tested with poly O and poly H Salmonella antiserum. When the samples were stored for 24h there was no difference between PE and DE (p > 0.05). However after 96h the PE was superior to DE (p 0.05). For enrichment, better results were seen with RVN broth (p 0.05). The XLD yielded
RESUMO Este trabalho foi desenvolvido para avaliar comparativamente o isolamento de Salmonella sorotipos Enteritidis (SE) e Typhimurium (STM) a partir do enriquecimento direto (ED) ou processamento com pré-enriquecimento (PE) de amostras de fezes de aves adultas, armazenadas em água peptonada tamponada a 1% (APT) por 24 ou 96h a 4º C. Utilizou-se os caldos de enriquecimento Rapapport-Vassiliadis novobiocina (RVN), tetrationato-novobiocina (TN) e selenitonovobiocina (SN) e os meios para plaqueamento ágar verde brilhante (VB), ágar de MacConkey (MC), ágar de Hektoen (HE), ágar Salmonella-Shigella (SS), ágar xilose lisina desoxicolato (XLD) e ágar xilose lisina tergitol 4 (XLT4). O procedimento bacteriológico incluiu as etapas de pré-enriquecimento, enriquecimento em caldo seletivo, plaqueamento, testes bioquímicos presuntivos e confirmação sorológica com utilização de soros polivalentes anti-antígenos somáticos e anti-antígenos flagelares de Salmonella. Não houve diferença estatisticamente significativa (p > 0,05) para as amostras armazenadas por 24h submetidas tanto ao PE quanto ao ED. Entretanto, em armazenagem por 96h o número de isolamentos nas amostras submetidas ao PE foi estatisticamente superior às submetidas ao ED (p 0,05). Quanto aos caldos enriquecedores, não houve diferença estatística de número de isolamentos (p > 0,05) entre os caldos SN e TN, mas o caldo RVN mostrou-se estatisticamente superior aos demais (p 0,05). Para os meios de plaqueamento, o XLD destacou-se por promover maior número de recuperações, embora sem significado estatístico (p > 0,05) para as amostras estocadas por 24h. Entre os dois sorotipos de Salmonella (SE e STM) não houve diferença estatística no número de recuperações (p > 0,05).