RESUMO
Sialolithiasis are the most frequent salivary gland disease, mainly affecting the submandibular gland. With the advent of minimally invasive techniques, total salivary gland removal should not be considered as the first-line treatment anymore. Extracorporeal Shock Wave Lithotripsy (ESWL) is an alternative to surgery preserving the gland. The objective of our retrospective study was to evaluate the efficiency of ESWL on pain and obstructive syndrome in patients suffering from sialolithiasis. The global result felt by the patients was also considered. All patients treated between October 2009 and July 2016 for sialolithiasis by ESWL in our department were included. They were divided into two groups according to the concerned gland: a parotid gland (PG) and a submandibular gland (SMG) group. Our retrospective telephone questionnaire consisted in 4 questions about their symptomatology before and after ESWL, including pain self-evaluation before and after treatment. They were finally asked to evaluate the global result of the ESWL treatment: excellent, good, mean, or poor. In total, 55 patients were included in this study, 38 patients in PG group and 17 patients in SMG group. We observed a decrease of pain and obstructive syndrom after ESWL procedure in both groups. Better results were found on the obstructive syndrome in the PG group. Very few side-effects were reported by patients. Given that it has very few side effects, ESWL can easily be considered as first line treatment for sialolithiasis to avoid heavier treatments such as surgery. It should be the first-line treatment for symptomatic parotid sialolithiases. The treatment of symptomatic submandibular sialolithiases depends on the topography of the lithiasis.
Assuntos
Litotripsia , Cálculos das Glândulas Salivares , Doenças da Glândula Submandibular , Humanos , Estudos Retrospectivos , Glândula SubmandibularRESUMO
OBJECTIVE: Since the biological effect of cartilage mediators is generally studied in a non-physiologic environment of 21% O2, we investigated the effects of a chronic hypoxia on the capability of articular chondrocytes to respond to one anabolic stimulation. DESIGN: Human Articular Chondrocytes (HACs) were cultured under hypoxia and stimulated with the chondrogenic growth factor BMP-2. The phenotype of the chondrocytes was studied by RT-PCR, and the cartilage-specific type II collagen production and deposition were also examined by western immunoblot and immunofluorescence. The Bone Morphogenetic protein (BMP) signalling pathway was also analysed. RESULTS: BMP-2 is much more efficient to stimulate the expression of the cartilage-specific gene COL2A1 by HACs when cultured under hypoxia (1%O2) compared to normoxia (21%O2). Analysis of the BMP-activated signalling shows that the Smad pathway is inhibited under hypoxia, whereas p38 MAPK is activated, and is involved in a synergy between hypoxia and BMP signalling, thus contributing to the enhanced anabolic response. CONCLUSIONS: Our study shows that hypoxia interplays with a chondrogenic factor and enhances the overall anabolic activity of the HACs. Alternatively to Hypoxia-Inducible Factor (HIF) signalling, and through a cross-talk with the BMP signalling which involves the p38 pathway, hypoxic stimulation markedly increases the capability of chondrocytes to produce the cartilage-specific type II collagen. Therefore our study provides new evidences of the multilayered effects of hypoxia in the anabolic functions of chondrocytes. This understanding may help promoting the anabolic function of articular chondrocytes, and thus improving their manipulation for cell therapy.
Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Cartilagem Articular/metabolismo , Hipóxia Celular/fisiologia , Condrócitos/metabolismo , Colágeno Tipo II/biossíntese , Cartilagem Articular/citologia , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Ativação Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
We previously reported that RGTA, a synthetic heparan sulfate mimetic, induces almost complete closure of craniotomy defects one month after surgery in adult rats. RGTA-treated wounds showed features suggesting unusual cell and matrix interactions reminiscent of developmental events. As healing success or failure is determined shortly after wounding, we examined early events in RGTA-treated wounds. Collagen plasters soaked in a solution of RGTA11 (1.5 Microg per piece) or saline (control) were implanted in rat craniotomy defects. Seven control and seven treated rats were killed daily from days 1 to 7 after surgery. The lesions and adjacent tissues were sampled and processed for morphometry. A layer of type III collagen along the dura mater (DM) thickened up to day 5 in RGTA-treated wounds (p < 0.05 vs day 1), but became thinner in control wounds. Alkaline phosphatase-positive osteoprogenitor cells were detected on day 1 in this layer. Their number increased, and they migrated toward the mid-sagittal sinus and to connective tissue adjacent to the sinus, where they aggregated and differentiated into osteoblasts, forming bone nodules on day 6. These features were not seen in control wounds. Angiogenesis was significantly enhanced in RGTA-treated wounds, especially near the sinus. In vitro, bovine bone endothelial (BBE) cell proliferation was inhibited by RGTA11 in a concentration-dependent manner. In contrast, RGTA11 strongly enhanced the effect of fibroblast growth factor-2 on BBE cell proliferation. These results show that RGTA11, possibly by interacting with heparin-binding growth factors, elicits vascular reactions accompanying the recruitment of a large pool of committed osteoprogenitors from the DM. The DM and the sinus appear to be important centers of organization for craniotomy defect healing. RGTA probably creates an environment that starts a program of directing healing towards bone formation and defect closure.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Craniotomia , Dextranos/uso terapêutico , Crânio/fisiologia , Cicatrização/efeitos dos fármacos , Animais , Bovinos , Células Cultivadas , Colágeno/análise , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Cinética , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Ratos , Ratos Wistar , Crânio/química , Crânio/citologia , Fatores de TempoRESUMO
The objective of the present study was to assess the efficiency and benefit of a chemomechanical system for carious dentin removal, Carisolv, in general practice. A revised caries classification, the site/stage concept, was used to describe the clinical situations of all carious lesions treated. The study was performed by 12 investigators, and 120 carious lesions were treated with Carisolv. Sixty percent of the cases were treated without anaesthesia, and we found a significant correlation between chemomechanical treatment without anaesthesia and absence of pain ( P=0.01). In 78.3% of the cases, carious dentin was totally removed with Carisolv, and in 21.7%, the dentin treatment was completed by drilling. In cases performed with Carisolv alone, the time required to remove carious dentin was 11.1+/-9.51 min (mean+/-SD). Treatment time was equivalent for all sites and increased significantly with each successive stage of lesion progression ( P<0.001). In 82.5% of cases, the clinicians were satisfied with Carisolv, and in 99.2%, so were the patients. We conclude that, using clinical examination methods, Carisolv seems to remove carious dentin at all sites and stages of carious lesions but must be made more efficient for use in general practice.
Assuntos
Cárie Dentária/classificação , Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Ácido Glutâmico/uso terapêutico , Leucina/uso terapêutico , Lisina/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestesia Dentária , Criança , Dentina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Inquéritos e Questionários , Fatores de TempoRESUMO
RGTA, a new family of dextran-derived healing agents, promotes the repair of various tissues, including bone. In this study, we examined whether a dose of RGTA lower than in our previous studies could still modify the healing pattern in craniotomy defects. In 24 rats, two defects (3 mm diameter) were drilled on either side of the calvaria sagittal suture. The right defect was filled with a piece of collagen soaked with RGTA in phosphate-buffered saline (PBS; 4 microg/ml), and the left one with collagen soaked in PBS only. After 7, 14 and 21 days, the calvaria were removed and processed for histometry. On day 7, in contrast with the control defects, the treated sites were inflammation-free and centripetal bone plates had started to grow. By day 14, the bone filling was significantly enhanced in the treated defects (+290%, p<0.05), and isolated bone nodules had formed within the fibrous connective tissue (= fibrous hammock) joining the defect edges. The hammock had already differentiated by day 7 in all the RGTA-treated defects, and it was significantly thicker on days 14 (+190%, p<0.05) and 21 (+139%, p<0.05). The colonization of the hammock by mast cells was increased in the treated sites (+320%, p<0.05 on day 21). On day 7, most of the bony edges of the treated defects had been resorbed by osteoclasts, while the process only started in the controls. These data indicate that a low dose of RGTA modified the cascade of events occurring at the initial stages of repair, so that the tissular maturation of the treated defects was more rapid. In fact the use of RGTA in the wounds provoked a shift from a fibrous repair as seen in the controls, to a bone reconstruction favoring defect closure.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Craniotomia , Dextranos/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Avaliação Pré-Clínica de Medicamentos , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
OBJECTIVE: To study the efficacy of two types of intervention to stop tobacco dependency. DESIGN: Randomised clinical trial. SETTING: Primary care centre. PATIENTS AND OTHER PARTICIPANTS: Smokers recruited from among the health centre users through the preventive activities and health promotion programme. INDEPENDENT VARIABLE: type of intervention. General variables: age, sex, marital status, educational level, work situation, cohabitation with children, smokers at home, number of years smoking, type of tobacco. There were two types of intervention: a) Minimal Intervention (MI). b) Advanced Intervention (AI). 54 patients were included, with 6 losses. 21 were assigned at random to the MI group and 27 to the AI group. Progress was measured at 15 days, 1 month, 3 months, 6 months and a year. RESULTS: In the MI, 23.8% were abstinent at 15 days; the same percentage at one month and 3 months; 19% at 6 months; and 14.3% remained abstinent after a year. In the AI, 51.9% were abstinent at 15 days; 48.1% at both one and 3 months; 25.9% at 6 months; and 22.2% were still not smoking after a year. No significant differences between the two interventions were found in any of the observations. CONCLUSIONS: These data do not show that one intervention is better than the other. With the passage of time the effect of the intervention decreased in both groups.
Assuntos
Abandono do Hábito de Fumar/métodos , Adulto , Feminino , Humanos , MasculinoRESUMO
RGTA are chemically defined compounds which proved to be very potent healing agents in various tissue repair models including skin, muscle and nerve. These chemicals are believed to protect endogenously released heparin-binding growth factors and enhance their bioavailability during healing. In craniotomy defects that do not heal spontaneously in adults, RGTA promoted dose-dependent skull closure. The aim of this work was to characterize, in the same model, the events associated with wound closure by studying the expression of the osteoblastic phenotype and the distribution of some matrix proteins during RGTA11-induced bone healing. Craniotomy defects in rats were implanted with collagen plasters soaked in a solution of RGTA11 (1.5 micrograms per piece). The skulls were removed 30 days after wounding, a stage of almost complete bone filling in treated samples. Bone formed only at the edges of the defect in controls, while it formed also at the center in the form of nodules in the treated samples. RGTA11 modified the amount and distribution of the tissues including bone in the wounds. In some RGTA11-treated samples, skull closure by bone occurred and the median suture was restored. In the treated defects, alkaline phosphatase-positive (osteoprogenitor) cells were far more numerous and were distributed differently. Type I and III collagen and fibronectin deposition was markedly enhanced in the bone compartment of the wounds. Secretory osteoblasts released type III collagen. Osteocalcin expression was enhanced by RGTA11. RGTA11 thus modified the healing pattern by increasing both the cellularity and the synthesis of a bone-competent extracellular matrix, thereby restoring the original anatomy of the skull. Flat bone regeneration can be triggered in adults through developmental events (i.e. nodule formation, secretion of type III collagen by osteoblasts, suture restoration...) that are no longer operative in the wounds of mature individuals.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Craniotomia , Dextranos/farmacologia , Crânio/fisiologia , Cicatrização/efeitos dos fármacos , Fosfatase Alcalina/análise , Animais , Colágeno/análise , Fibronectinas/análise , Imuno-Histoquímica , Masculino , Osteoblastos/citologia , Osteocalcina/análise , Radiografia , Ratos , Crânio/química , Crânio/citologia , Crânio/diagnóstico por imagemRESUMO
We describe in this paper how the STEAM sequence can be an efficient tool to obtain images free of flow artifacts in anatomical situation where the spin echo failed. The simplest way to eliminate flow artifacts is to exploit the dephasing induced by motion in magnetic field gradients and to reduce to zero the signal from moving tissues. This can be achieve by increasing the time elapsed between the spin excitation and the signal observed. Because of T2 relaxation, such an increase results in a signal decrease when the spin echo sequence is used. The STEAM sequence has the unique property that the time elapsed between observation and excitation can be increased without change in T2 value and so allows a good suppression of signals from the moving spins with short TE. Our results demonstrate that, although the stimulated echo intensity is only half that of a spin echo taken at the same read out time, the advantages of STEAM imaging can compensate for this partial loss in signal to noise in some particular clinical situations. The influence of mixing time on contrast has been evaluated using thoracic spine imaging and it has been shown that contrast between spine and CSF can be significantly improved (+ 60%) when TM is increased (from 17 ms to 50 ms). In the same time, the contrast between spine and fat issue decreases (40%). This last effect facilitates the adjustment of contrast window. Suppression of motion artifacts has first been evaluated with thoracic spine imaging, using a whole body coil. Suppression of artifacts was better than that obtained with a flow compensated spin echo sequence, especially in the case of kyphotic patients when a presaturation band was inefficient. In a second step suppression of motion artifacts has been evaluated from posterior fossa examination after injection of a paramagnetic contrast agent. The images obtained with the stimulated echo sequence show a dramatic reduction of signal from blood in the lateral sinus, and therefore an increase of quality by elimination of motion artifacts.
Assuntos
Encéfalo/patologia , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Coluna Vertebral/patologia , Tecido Adiposo/patologia , Artefatos , Sangue , Neoplasias Cerebelares/diagnóstico , Neoplasias Cerebelares/secundário , Líquido Cefalorraquidiano , Meios de Contraste , Fossa Craniana Posterior/patologia , Cavidades Cranianas/patologia , Humanos , Cifose/diagnóstico , Cifose/patologia , Medula Espinal/patologia , Compressão da Medula Espinal/diagnóstico , Compressão da Medula Espinal/patologia , Vértebras Torácicas/patologiaRESUMO
Two collections of strains of Pasteurella were studied for epidemiological purposes by ribotyping and random amplified polymorphic DNA (RAPD) assays. These strains were isolated through two different structures of animal productions: cattle and rabbit. Forty strains of P. haemolytica from cattle reared in independent breeding-herds belonged to only 3 ribotypes after digestion with HindIII and PvuII. No further discrimination of these strains was obtained by RAPD assays. All these 40 strains showed more than 90% of similarity. This result was consistent with the hypothesis of a clonal dissemination of these strains in bovine herds, possible favoured by the large use of antibiotics. Forty-one strains of P. multocida were isolated in rabbits flocks belonging to 16 breeders. Six of these were linked by commercial relationships. Twenty-eight out of the 29 strains isolated through this commercial network belonged to only three ribotypes whereas the 12 strains from independant breeders belonged to 9 ribotypes. Results of RAPD assays were in accordance with those of ribotyping and validate the use of RAPD assays for epidemiological studies of Pasteurella strains.
Assuntos
Doenças dos Bovinos , Mannheimia haemolytica/isolamento & purificação , Infecções por Pasteurella/veterinária , Pasteurella multocida/isolamento & purificação , Técnica de Amplificação ao Acaso de DNA Polimórfico/veterinária , Animais , Bovinos , Primers do DNA , Desoxirribonuclease HindIII , Desoxirribonucleases de Sítio Específico do Tipo II , Métodos Epidemiológicos/veterinária , Mannheimia haemolytica/classificação , Infecções por Pasteurella/diagnóstico , Infecções por Pasteurella/epidemiologia , Pasteurella multocida/classificação , Reação em Cadeia da Polimerase/métodos , Coelhos , Reprodutibilidade dos Testes , Mapeamento por Restrição , SorotipagemRESUMO
Chloramphenicol, which had been used extensively for antimicrobial veterinary therapy, was prohibited in Europe in 1994. Soon after it became available, resistance to this drug was detected, generally conferred by plasmids encoding inactivating enzymes, the chloramphenicol acetyltransferases (CAT), in Gram-negative as well as in Gram-positive bacteria. In the last few years, resistance to antibiotics emerged in Pasteurella strains from breeding herds and this evolution was followed by a national surveillance network. Chloramphenicol-resistance was more recently detected in multiresistant strains. We studied 25 strains of Pasteurella, selected for their resistance to chloramphenicol. Production of a CAT was demonstrated in all these strains. PCR amplification indicated that the CAT produced was of type III for 23 of them. In these strains, chloramphenicol-resistance was mediated by plasmids of about 5.1 kb. Southern blots on restriction fragments suggested a high degree of homology between these 5.1 kb plasmids. In the two other strains, production of a CAT type I was demonstrated, and the corresponding genes were either shown on a plasmid of 17 or 5.5 kb.
Assuntos
Cloranfenicol O-Acetiltransferase/metabolismo , Cloranfenicol/farmacologia , Mannheimia haemolytica/efeitos dos fármacos , Infecções por Pasteurella/tratamento farmacológico , Pasteurella multocida/efeitos dos fármacos , Animais , Southern Blotting , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/microbiologia , Cloranfenicol/uso terapêutico , Resistência ao Cloranfenicol , Resistência a Múltiplos Medicamentos , Infecções por Pasteurella/veterinária , Plasmídeos , Reação em Cadeia da PolimeraseRESUMO
Discrimination of 70 Salmonella strains previously studied by ribotyping was realized by RAPD and ERIC-PCR analysis. RAPD results on the 56 S. typhimurium isolates did not closely match those of ribotyping. With ERIC-PCR, two fingerprints only were obtained. For the 14 S. enteritidis strains, a helpful discrimination was obtained with RAPD analysis, while ERIC-PCR resulted in a single fingerprint.
Assuntos
Técnicas de Tipagem Bacteriana , Reação em Cadeia da Polimerase/métodos , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella/classificação , Animais , Estudos de Avaliação como Assunto , França/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Salmonella/genética , Salmonelose Animal/epidemiologia , Salmonella enteritidis/classificação , Salmonella enteritidis/genética , Salmonella typhimurium/classificação , Salmonella typhimurium/genéticaRESUMO
Quinolone-resistant Escherichia coli strains were isolated from poultry clinical samples in Saudi Arabia. The poultry flocks had been treated with oxolinic acid or flumequine prophylaxis. The measure of the uptake of fluoroquinolones showed that none of the strains had a reduced accumulation of quinolones. The result of complementation with the wild-type E. coli gyrA gene, which restored fluoroquinolone susceptibility, and the isolation of DNA gyrase from six isolates indicated that the resistant strains had an altered DNA gyrase. The minimum effective dose of ciprofloxacin for inhibition of supercoiling catalyzed by the isolated gyrases varied from 0.085 microgram/ml for a susceptible isolate (MIC < 4 micrograms/ml) up to 96 micrograms/ml for the more resistant one (strain 215, MIC > 64 micrograms/ml). For the same two isolates, the minimum effective doses of sparfloxacin varied from 0.17 up to 380 micrograms/ml. The in vitro selection of spontaneous single-step fluoroquinolone-resistant mutants using ciprofloxacin suggested that the more resistant mutants are likely the result of several mutations. These results also show that, as in human medicine, cross-resistance between older quinolones and fluoroquinolones can exist in veterinary isolates and reiterate the need for the prudent use of these drugs.
Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Aves Domésticas/microbiologia , 4-Quinolonas , Animais , DNA Topoisomerases Tipo II/isolamento & purificação , Resistência Microbiana a Medicamentos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Fluoroquinolonas , Testes de Sensibilidade Microbiana , Mutação , FenótipoRESUMO
Animals are a wide source of salmonellas for humans and their environment. Domestic ruminants play an important role because of their high susceptibility to salmonellas infection giving an acute disease with massive salmonella excretion and mortality if lack of treatment. As in human medicine use of antibiotics at therapeutic doses in animals can lead to the selection of resistant strains may be pathogenic for humans by direct contact or through environment and food. Taking into account the importance of salmonellosis on calves in rearing units, CNEVA Lyon has set up since 1982 a national network for antimicrobial resistance monitoring of main bacterial pathogens in bovine. This network allowed to detect a recent evolution of antimicrobial susceptibility in salmonella from dairy cows related with new problem of salmonellosis in cattle.
RESUMO
Resistance to antibiotics has recently emerged in Pasteurella haemolytica and Pasteurella multocida isolated from bovine herds. Forty-two clinical strains resistant to antibiotics and isolated through a French national network from different origins were analysed for their resistance to tetracycline. The MICs of tetracycline ranged from 32-256 mg/L. The resistance determinants Tet B and Tet M were detected in two strains, in which they are probably chromosomal.
Assuntos
Genes Bacterianos , Mannheimia haemolytica/genética , Pasteurella multocida/genética , Resistência a Tetraciclina/genética , Animais , BovinosRESUMO
Since 1982, a national veterinary network has been involved in the monitoring of resistance to antimicrobial agents in the main pathogenic bacteria isolated from diseased cattle in France. It is based on 40 regional veterinary diagnostic laboratories and managed by a central reference laboratory (CNEVA Lyon). Highly standardized methods are used in the diagnostic laboratories. This network collects up-to-date information on antimicrobial resistance in veterinary isolates and gathers strains for specific studies on fastidious bacteria and for the analysis of mechanisms of resistance to antibiotics. Such a permanent survey is essential to establish a rational veterinary antibiotic policy. It could be connected to other compatible systems developed in other fields such as human medicine, food, and environment, to evaluate the importance of resistance and R-factors spread for public health. The limits and perspectives of this surveillance system are discussed.
Assuntos
Bactérias/efeitos dos fármacos , Doenças dos Bovinos/microbiologia , Resistência Microbiana a Medicamentos , Envelhecimento/fisiologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Bovinos , Doenças dos Bovinos/epidemiologia , Resistência Microbiana a Medicamentos/genética , França/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Fatores RRESUMO
BACKGROUND: The nature of the multinucleated giant cells (MNGC) elicited in contact with implantable biomaterials is still indecisive. METHOD: In Wistar rats the MNGC recruited after the implantation of hydroxyapatite (HA) particles in standardized skull defects were examined morphologically (at both the light and electron microscope levels), enzymatically (tartrate-resistant acid phosphatase and non-specific esterase), and after a challenge with salmon calcitonin. RESULTS: The MNGC were of great size and contained abundant mitochondria, vacuoles, and vesicles throughout the cytoplasm; they were either tightly apposed to the HA surface or had long and thin processes penetrating the material. When processed for tartrate-resistant acid phosphatase, only a few cells were weakly stained. The staining was totally suppressed when samples were pretreated with cyanuric chloride in the MNGC but not in the host osteoclasts. Calcitonin induced the withdrawal of the host osteoclasts from the bone surface while the MNGC remained in contact with the HA material. CONCLUSION: The MNGC recruited to HA particles did not exhibit the morphologic, enzymatic and functional characteristics of the osteoclasts, and consequently must be regarded as macrophage polykaryons.
Assuntos
Durapatita/toxicidade , Células Gigantes de Corpo Estranho/patologia , Osteoclastos/patologia , Próteses e Implantes/efeitos adversos , Fosfatase Ácida/metabolismo , Animais , Calcitonina/farmacologia , Carboxilesterase , Hidrolases de Éster Carboxílico/metabolismo , Núcleo Celular/patologia , Cerâmica/toxicidade , Craniotomia , Células Gigantes de Corpo Estranho/efeitos dos fármacos , Células Gigantes de Corpo Estranho/enzimologia , Macrófagos/enzimologia , Macrófagos/patologia , Masculino , Microscopia Eletrônica , Osteoclastos/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
The genetic diversity and clonal relationships among 77 Escherichia coli strains isolated in France from diarrhoeic rabbits and that belonged to seven O serogroups including the predominant O103 serogroup, were estimated by ribotyping and random amplified polymorphic DNA (RAPD) assays. Fifteen ribotypes were defined. Most of the highly pathogenic O103 strains could be assigned to two major groups. Non-pathogenic strains were clearly distinguished. RAPD assays generally matched ribotyping, or gave more precision for subdividing strains from the two main O103 groups. The results on strains isolated from different areas and over a 9-year period showed the relevance of the association of these two methods for the survey of the spread of strains in breeding flocks and illustrated clonal diffusion in rabbit production structures.
Assuntos
Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Escherichia coli/classificação , Escherichia coli/genética , Coelhos/microbiologia , Animais , Técnicas de Tipagem Bacteriana/veterinária , Sequência de Bases , Clonagem Molecular , Impressões Digitais de DNA/veterinária , Diarreia/microbiologia , Infecções por Escherichia coli/microbiologia , Variação Genética , Dados de Sequência MolecularRESUMO
Production of aerobactin has been reported to be a virulence factor in members of the family Enterobacteriaceae. To investigate the protection afforded by humoral immunity directed towards aerobactin in infectious diseases caused by aerobactin-producing strains, we tested the efficacy of mAbAERO1, a murine monoclonal antibody directed to ferric aerobactin, which, in vitro, was found to impair the growth of aerobactin-dependent strains of Enterobacteriaceae under iron-limited conditions. The mortality of mice experimentally infected with the aerobactin-producing strains Escherichia coli V2019 (LD50 = 3.5 x 10(5) CFU/mice) or Klebsiella pneumoniae Caroli (LD50 = 1.3 CFU/mice) was not reduced when 1 mg of mAbAERO1 was injected intravenously 1 h before or 1 h after bacterial challenge. Nor was mortality reduced after challenge with either E. coli V2019 or K. pneumoniae Caroli, even though the active immunization of mice with purified FeAero (ferric aerobactin) conjugated with thyroglobulin as followed by a rise in systemic anti-FeAero antibodies. Lastly, chicks born of hens immunized with FeAero showed evidence of antibody transmission towards FeAero, but were not protected when challenged with E. coli MT78, an aerobactin-producing strain highly virulent for chickens. Therefore, under the experimental conditions tested, humoral immunity against aerobactin appeared to play only a minor role in protection against infections caused by aerobactin-producing members of the family Enterobacteriaceae. However, other experimental models should be tested to confirm these observations.
Assuntos
Vacinas Bacterianas/uso terapêutico , Escherichia coli/imunologia , Ácidos Hidroxâmicos/imunologia , Klebsiella pneumoniae/imunologia , Vacinas Conjugadas/uso terapêutico , Animais , Formação de Anticorpos , Galinhas , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/prevenção & controle , Imunidade Ativa , Infecções por Klebsiella/imunologia , Infecções por Klebsiella/prevenção & controle , CamundongosRESUMO
Seventy selected strains of Salmonella typhimurium and S. enteritidis isolated from related poultry flocks in three independent geographical areas were characterized by phenotypic and genotypic methods to compare the usefulness of the methods in epidemiological studies. The 56 S. typhimurium isolates were poorly discriminated by their biotypes, resistance patterns, and plasmid profiles. Nine different ribotypes were obtained after DNA digestion by BglII, PvuII, and SmaI. Seven IS200 types, characterized by six to nine copies of IS200 on the chromosome, were detected after digestion of genomic DNA by PstI. These studies resulted in the definition of 15 clonal lineages distributed in three clusters. The 14 S. enteritidis strains were not discriminated either by ribotyping or by detection of IS200 (IS200 typing), but were separated on the basis of antibiotic resistance and plasmid profiling. The stability of the insertion sequence type was confirmed by inoculation of an S. typhimurium strain to axenic chickens reared for 15 weeks in sterile isolators.