RESUMEN
AIM: To retrospectively evaluate the performance of reinforced glass ionomer restorations placed in load-bearing surfaces of posterior teeth in three UK general dental practices. METHODS: Inclusion criteria for the participating practitioners were that they would be able to find, in their regularly attending patients' mouths, a minimum of 30 Fuji IX restorations placed in load-bearing cavities in posterior teeth. The three practitioners who agreed to participate were given training in the methods of assessment of restorations. Presence/absence of the restoration, presence of secondary caries, anatomic form, margin adaptation, margin discolouration, surface roughness and colour match were recorded. RESULTS: Three general dental practitioners and 169 restorations in 116 patients were included in the study. Seventy-eight percent of restorations were placed in molar teeth, the remainder in premolar teeth, with 67 being Class I and 102 Class II. The mean age of restorations at examination was 25 months, ranging from five months to 56 months. Of the restorations examined, 98% (n = 166) were found to be present and intact. No secondary caries was detected clinically. Three restorations were found to have fractured. CONCLUSION: Reinforced glass ionomer restorations placed in load-bearing situations in patients attending three dental practices in the UK were found to be performing satisfactorily at two years. Further investigations, of improved rigour, may now be indicated to more fully assess the performance of such restorations in the long term.
Asunto(s)
Restauración Dental Permanente/métodos , Cementos de Ionómero Vítreo , Adolescente , Adulto , Anciano , Diente Premolar , Fracaso de la Restauración Dental , Restauración Dental Permanente/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diente Molar , Estudios Retrospectivos , Reino UnidoRESUMEN
OBJECTIVE: The aim of this study was to assess the clinical performance at two years of 100 Solitaire 2 restorations placed in five United Kingdom dental practices by members of a practice-based research group. METHOD AND MATERIALS: Restorations were assessed after two years by a trained evaluator and the dental practitioner who had placed the material, for anatomic form, marginal adaptation, surface roughness, gingival condition and the presence or absence of secondary caries. In addition, the patients completed a questionnaire requesting details of the comfort and performance of the Solitaire 2 restoration(s). RESULTS: A total of 88 (58 Class II and 30 Class I) restorations of Solitaire 2 placed in 49 patients (mean age 43 years) were assessed. Twelve restorations could not be evaluated because of patient unavailability for the dates of the examinations. Two Class II restorations (2%) had failed by the time of the two-year evaluation and the remaining 86 restorations were found to be intact with no secondary caries. A high percentage of optimal scores were recorded for anatomic form and surface roughness. The colour match of two restorations (2%) was recorded as an obvious mismatch, but otherwise no unacceptable scores were recorded. CONCLUSIONS: After two years of clinical service a high proportion (96%) of the Solitaire 2 restorations that were available for re-examination, placed in general dental practice settings, were found to be performing satisfactorily.
Asunto(s)
Resinas Compuestas , Restauración Dental Permanente/métodos , Adhesivos , Adulto , Recubrimiento Dental Adhesivo , Fracaso de la Restauración Dental , Recubrimientos Dentinarios , Compuestos Epoxi , Femenino , Estudios de Seguimiento , Odontología General , Humanos , Masculino , Metacrilatos , Evaluación de Resultado en la Atención de Salud , Cementos de Resina , Encuestas y Cuestionarios , Reino UnidoRESUMEN
Between April 1996 and March 1997 we examined 5093 samples of raw beef and lamb products for the presence of E. coli O157. Samples were purchased from 81 small butchers' shops in south Yorkshire. In March 1997 we also examined five samples of dried mint for the presence of E. coli O157. Strains of E. coli O157 were isolated by enrichment culture in modified buffered peptone water followed by immunomagnetic separation and culture of magnetic beads onto cefixime tellurite sorbitol MacConkey agar. Strains were characterized by phage typing, toxin genotyping and plasmid analysis. Strains of E. coli O157 were isolated from 72 (1.4%) of 5093 samples; it was isolated from 36 (1.1%) of 3216 samples of beef products and from 29 (2.9%) samples of lamb products. The highest prevalence was found in lamb sausages and lamb burgers where E. coli O157 was isolated from 3 (4.1%) of 73 and 18 (3.7%) of 484 samples respectively. Strains of E. coli O157 were isolated most frequently during early summer. Strains of E. coli O157 were also isolated from 2 of 5 samples of dried mint although we did not determine how the mint had become contaminated. All isolates of E. coli O157 were Verocytotoxin-producing as determined by both Vero cell assay and DNA hybridization for the genes encoding Verocytotoxin and all were positive for the eaeA gene. A combination of phage typing, toxin genotyping and plasmid profile subdivided the 72 strains of E. coli isolated into 20 different subtypes, of which 18 were indistinguishable from strains isolated previously from cattle and sheep; of these 18 strains, 8 were indistinguishable from strains isolated from human cases of infection during the study period.
Asunto(s)
Escherichia coli O157/aislamiento & purificación , Inspección de Alimentos , Microbiología de Alimentos , Carne/microbiología , Animales , Toxinas Bacterianas/biosíntesis , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacología , Tipificación de Bacteriófagos , Bovinos , Chlorocebus aethiops , Escherichia coli O157/química , Escherichia coli O157/genética , Escherichia coli O157/metabolismo , Genotipo , Separación Inmunomagnética , Lamiaceae/microbiología , Plásmidos/análisis , Ovinos , Toxina Shiga I , Reino Unido , Células Vero/citología , Células Vero/efectos de los fármacosRESUMEN
Three members of family A, who had diarrhoea on 20 October, lived on a small arable farm which had 10 cattle. Manure from the animals was used to fertilize the ground for growing potatoes which were then offered for retail sale, unwashed, directly from the farm. The mother from family B bought potatoes, which were covered with manure, from family A in early November and over the subsequent 10 days she became ill with diarrhoea and her daughter and son both became ill with bloody diarrhoea. The mother from family C visited family B while the daughter from the latter family was symptomatic; the mother developed diarrhoea several days later. The mother and two sons from family D visited family B while the son from the latter family was symptomatic; the first son developed bloody diarrhoea 6 days later which progressed to development of haemolytic-uraemic syndrome. Direct culture of faecal samples onto cefixime rhamnose sorbitol MacConkey agar failed to isolate E. coli O157 from any of the symptomatic patients, and direct culture onto cefixime tellurite sorbitol MacConkey agar isolated the organism from only one patient. In contrast, a combination of isolation of E. coli O157 by immunomagnetic separation and detection of E. coli O157-specific secretory IgA, suggested E. coli O157 infection in all eight symptomatic patients, but not in any of the family members who were not ill. Two children who excreted the organism for 60 and 89 days respectively were the only two patients who did not develop a secretory IgA response. E. coli O157 was not isolated from potatoes from the farm and faecal samples from the farm animals were not available for examination. The study illustrates the need to use the most sensitive methods available during the investigation and follow up of cases of E. coli O157 infection.
Asunto(s)
Diarrea/microbiología , Brotes de Enfermedades , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Heces/microbiología , Estiércol/microbiología , Técnicas Microbiológicas/normas , Solanum tuberosum/microbiología , Animales , Bovinos , Inglaterra , Femenino , Humanos , Separación Inmunomagnética , Masculino , Sensibilidad y EspecificidadRESUMEN
Samples of rectal faeces were collected immediately after slaughter from 400 cattle each month for a 1-year period and from 1000 each of sheep, pigs and poultry over the same period. Samples were examined for Escherichia coli O157 by enrichment culture in buffered peptone water with vancomycin, cefixime and cefsulodin followed by immunomagnetic separation and culture of magnetic particles onto cefixime tellurite sorbitol MacConkey agar. E. coli O157 was isolated from 752 (15.7%) of 4800 cattle, 22 (2.2%) of 1000 sheep and from 4 (0.4%) of 1000 pigs, but not from any of 1000 chickens. Of the cattle sampled. 1840 (38.4%) were prime beef animals, 1661 (34.6%) were dairy animals being culled and the status could not be determined for the other 1299 (27%) animals. E. coli O157 was found in 246 (13.4%) of the 1840 beef cattle and 268 (16.1%) of the 1661 dairy cattle. The monthly prevalence of E. coli O157 in cattle was 4.8-36.8% and was at its highest in spring and late summer. Seventeen of the 22 isolates from sheep were also made over the summer period. All E. coli O157 isolates from sheep and 749 (99.6%) of the 752 E. coli O157 isolates from cattle were verocytotoxigenic as determined by Vero cell assay and DNA hybridization, eaeA gene positive, contained a 92 kb plasmid and were thus typical of strains causing infections in man. In contrast isolates from pigs were non-toxigenic, eaeA gene negative and did not contain a 92 kb plasmid and would, therefore, be unlikely to be a source of infection for man.
Asunto(s)
Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157 , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Ovejas/microbiología , Enfermedades de los Porcinos/microbiología , Animales , Tipificación de Bacteriófagos , Bovinos , Inglaterra/epidemiología , Infecciones por Escherichia coli/epidemiología , Heces/microbiología , Prevalencia , Estaciones del Año , Ovinos , PorcinosRESUMEN
A commercial enzyme immunoassay (EIA) (E. coli O157 Visual Immunoassay; Tecra Diagnostics) performed on enrichment cultures in modified Escherichia coli broth (mECn) was compared with immunomagnetic separation (IMS) (Dynabeads anti-E. coli O157; Dynal) performed on enrichment cultures in modified buffered peptone water (BPW-VCC) for the detection of E. coli O157 in bovine fecal samples. Tests on fecal suspensions inoculated with each of 12 different strains of E. coli O157 showed that both the EIA and IMS methods were 10- to 100-fold more sensitive than direct culture or enrichment subculture methods for detection of the organism. EIA and IMS were then compared for detection of E. coli O157 in bovine rectal swabs. For confirmation of positive EIA tests, a commercial system (Immunocapture System [ICS]; Tecra Diagnostics) was compared with IMS; both were performed on mECn enrichment cultures. Of 200 rectal swabs examined, 17 gave positive results in the EIA which were confirmed by both confirmation systems, 2 gave positive results in the EIA which were confirmed by IMS but not by ICS, and 1 gave a positive result in the EIA which was confirmed by ICS but not by IMS. Of these 20, 15 were also positive by the BPW-VCC-IMS culture system; a further 3 samples were positive by this culture system but gave a negative result in the EIA. Eight samples were negative by the BPW-VCC-IMS culture system but gave a positive result in the EIA which could not be confirmed by either confirmation system. Further examination of the eight unconfirmed EIA-positive samples yielded sorbitol-fermenting E. coli O157 from three samples. Of the remaining five cultures, four were positive in an EIA for verocytotoxins (VT) and two were positive in a cell culture assay for VT1. The remaining 170 samples were negative by both EIA and BPW-VCC-IMS. The Tecra EIA and IMS are both technically simple and sensitive methods for detecting E. coli O157 in bovine fecal samples. There was no statistically significant difference between the numbers of positives detected by the different assays (P = 0.29).
Asunto(s)
Infecciones por Escherichia coli/diagnóstico , Escherichia coli O157/aislamiento & purificación , Técnicas para Inmunoenzimas , Separación Inmunomagnética/métodos , Animales , Técnicas Bacteriológicas , Bovinos , Medios de Cultivo/metabolismo , Escherichia coli O157/crecimiento & desarrollo , Heces/microbiología , Sensibilidad y EspecificidadRESUMEN
A dairy herd associated with Escherichia coli O157 infection in humans was studied for the 15 months following the outbreak to examine seasonal, age and management factors affecting faecal excretion of the organism and to determine the mode and frequency of milk contamination with the organism. Between May 1993 and July 1994, 28 visits were made to the farm to collect a total of 3593 rectal swabs from cows, heifers and calves and 329 milk samples. E. coli O157:H7 was isolated from 153 (4.3%) of 3593 bovine rectal swabs. The maximum prevalence at any one visit was 14% in lactating cows, 40% in non-lactating cows, 56% in calves and 68% in heifers. The prevalence in lactating cows, which was significantly lower than in the other groups, peaked during May-July 1993 and again briefly after the cattle were housed during November 1993 and then again during May 1994. Excretion rates of E. coli O157:H7 in lactating cows were highest during the first month after calving, falling during lactation and rising to another peak at 7 months postpartum. Between November 1993 and May 1994 there was no evidence of excretion in any group. Eighty-seven (74%) of the animals which excreted E. coli O157:H7 did so on only one occasion but 23 (32%) of 73 cows and heifers and 7 (16%) of 44 calves which excreted the organism did so on more than one occasion. E. coli O157:H7 was not isolated from milk taken from the bulk tank but it was isolated from individual milk samples (one milk jar and one fore-milk) from two animals previously shown to be faecal excretors of the organism. All isolates of E. coli O157:H7 obtained were of the same phage type, toxin genotype and plasmid profile.
Asunto(s)
Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157 , Leche/microbiología , Factores de Edad , Animales , Toxinas Bacterianas/análisis , Toxinas Bacterianas/biosíntesis , Tipificación de Bacteriófagos , Bovinos , Industria Lechera/métodos , Brotes de Enfermedades , Infecciones por Escherichia coli/transmisión , Heces/microbiología , Microbiología de Alimentos , Humanos , Plásmidos/análisis , Prevalencia , Estaciones del AñoAsunto(s)
Escherichia coli O157/aislamiento & purificación , Microbiología de Alimentos , Carne/microbiología , Animales , Toxinas Bacterianas/análisis , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Sondas de ADN , ADN Bacteriano/análisis , ADN Bacteriano/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/clasificación , Escherichia coli O157/metabolismo , Carne/análisis , Carne/normas , Prevalencia , Ovinos , Enfermedades de las Ovejas/epidemiología , Toxina Shiga IRESUMEN
Enrichment culture in modified buffered peptone water followed by immunomagnetic separation (IMS) with magnetic beads coated with an antibody against Escherichia coli O157 was compared with direct culture on cefixime rhamnose sorbitol MacConkey agar (CR-SMAC) and cefixime tellurite sorbitol MacConkey agar (CT-SMAC) for the isolation of E. coli O157 from human faeces. In total, 690 samples were examined; E. coli O157 was isolated from 25 samples by IMS but from only 15 and 12 by direct culture on CT-SMAC and CR-SMAC, respectively. The difference in sensitivity of detection was at its most marked on screening repeat faecal samples from known cases and samples from asymptomatic contacts, when of 12 strains of E. coli O157 isolated by IMS, only five were isolated by direct culture. IMS is a sensitive and simple technique for the isolation of E. coli O157 from human faecal samples and should prove useful in elucidating further the epidemiology of this micro-organism.
Asunto(s)
Toxinas Bacterianas/biosíntesis , Diarrea/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/aislamiento & purificación , Hemorragia Gastrointestinal/microbiología , Enfermedad Aguda , Animales , Antibacterianos , Toxinas Bacterianas/genética , Tipificación de Bacteriófagos , Cefixima , Cefotaxima/análogos & derivados , Chlorocebus aethiops , Medios de Cultivo , Citotoxinas/biosíntesis , Citotoxinas/genética , Sondas de ADN , ADN Bacteriano/análisis , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/metabolismo , Heces/microbiología , Humanos , Separación Inmunomagnética , Plásmidos , Ramnosa , Toxina Shiga I , Sorbitol , Células VeroRESUMEN
Fronto-temporal dementia is a clinical syndrome with a number of pathological substrates, including frontal lobe degeneration, Pick's disease, and motor neuron disease with dementia; it also includes patients with a primary progressive language disorder. Twenty-four brains were examined, using immunohistochemistry for glial fibrillary acidic protein (GFAP) and ferritin. Five cases of fronto-temporal dementia with a Pick's disease type of histology showed marked cortical gliosis with striking microglial activity in both grey and white matter. In seven cases of frontal lobe degeneration, there was little gliosis and microglial activity was confined largely to the white matter; two of the seven cases of progressive language disorder showed similar changes to frontal lobe degeneration. Five cases of motor neuron disease with dementia showed both astrocytic and microglial activity within the white matter. We suggest that cases of fronto-temporal dementia due to Pick type histology may result from a process which primarily involves grey matter, whereas cases of frontal lobe degeneration might represent a disorder of white matter.
Asunto(s)
Demencia/patología , Lóbulo Frontal/patología , Enfermedad de la Neurona Motora/patología , Neuroglía/patología , Lóbulo Temporal/patología , Astrocitos/patología , HumanosAsunto(s)
Toxinas Bacterianas/metabolismo , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/metabolismo , Enfermedades de las Ovejas/diagnóstico , Ovinos/microbiología , Animales , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/epidemiología , Escherichia coli O157/aislamiento & purificación , Incidencia , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/metabolismo , Toxina Shiga I , Reino Unido/epidemiologíaRESUMEN
Minced beef samples inoculated with Escherichia coli O157 were cultured in buffered peptone water supplemented with vancomycin, cefsulodin and cefixime (BPW-VCC) and subcultured to cefixime tellurite sorbitol MacConkey (CT-SMAC) agar both directly and after immunomagnetic separation (IMS) of the organism with magnetic beads coated with an antibody against E. coli O157 (Dynabeads anti-E. coli O157, Dynal, Oslo). E. coli O157 was recovered from initial inocula of 200 organisms/g by direct subculture and 2 organisms/g by IMS. Twelve strains of E. coli O157 of different combinations of phage type, H antigen and toxin genotype were all recovered from initial inocula of two organisms/g by IMS. Non-specific binding of other organisms to the magnetic beads could be reduced by washing of the beads in PBS with Tween-20 0.002-0.005% E. coli O157 was not bound by magnetic coated with an unrelated antibody. During investigation of a dairy herd that was possibly linked to a small outbreak of infection with E. coli O157, the organism was isolated from 2 of 279 forestream milk samples from individual cattle; both isolates were made only by the IMS technique. IMS is rapid, technically simple, and a specific method for isolation of E. coli O157 and will be useful in epidemiological studies.
Asunto(s)
Escherichia coli/aislamiento & purificación , Microbiología de Alimentos , Separación Inmunomagnética , Carne/microbiología , Leche/microbiología , Animales , Bovinos , Recuento de Colonia Microbiana , Escherichia coli/crecimiento & desarrollo , Estudios de Evaluación como Asunto , Microesferas , Sensibilidad y EspecificidadRESUMEN
Enrichment culture (EC) in modified buffered peptone water followed by immunomagnetic separation (IMS) with magnetic beads coated with an antibody against Escherichia coli O157 (Dynabeads anti-E. coli O157; Dynal, Oslo) was compared with direct culture on cefixime rhamnose sorbitol MacConkey agar (CR-SMAC) and cefixime tellurite sorbitol MacConkey agar (CT-SMAC) for the isolation of E. coli O157 from bovine faeces. When used to examine bovine faecal suspensions inoculated with 12 different strains of E. coli O157, EC-IMS was c. 100-fold more sensitive for detection of the organism than direct culture on either medium. During monitoring of a dairy herd, E. coli O157 was isolated from 84 (8.2%) of 1024 rectal swabs taken from cattle over a 4-month period; 23 (27.4% of the 84 strains were isolated by both direct culture and IMS (15 of the 23 were isolated on both media, five on CT-SMAC only and three on CR-SMAC only), whereas 61 (72.6%) strains were isolated by IMS only. IMS is a sensitive and simple technique for the isolation of E. coli O157 from bovine faecal samples and should prove useful in elucidating further the epidemiology of this organism.
Asunto(s)
Toxinas Bacterianas/biosíntesis , Citotoxinas/biosíntesis , Enterotoxinas/biosíntesis , Escherichia coli/aislamiento & purificación , Heces/microbiología , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Femenino , Separación Inmunomagnética , Toxina Shiga IRESUMEN
Cases of culture-confirmed clinically typical haemorrhagic colitis caused by verocytotoxin-producing (VT+) Escherichia coli O157 and age- and sex-matched control patients were examined for antibodies to E. coli O157. Serum samples from 28 cases and 34 patients in control group 1 were examined for VT1- and VT2-neutralising antibodies, E. coli O157 agglutinating antibodies, and by an enzyme immunoassay (EIA) technique for IgG antibodies against smooth lipopolysaccharide purified from E. coli O157 and for IgG antibodies against whole intact E. coli O157 cells. Differences between antibody titres were significant when compared by a Wilcoxon two-sample test for E. coli O157 agglutinating antibodies (p < 0.05) and IgG antibodies against whole cells (p < 0.001). The whole-cell EIA was used further to examine faecal samples from 93 cases and 47 patients in control group 2 for IgA antibodies. Elevated levels of faecal IgA specific for E. coli O157 were found in 59 (63.4%) of 93 cases but in only 10 (21.2%) of 47 control patients (p < 0.001); follow-up faecal samples from five cases all showed marked rises in levels of IgA that appeared to coincide with cessation of excretion of the organism. Detection of specific faecal IgA with a whole-cell EIA, although requiring further evaluation, may be a useful addition to tests currently available for the diagnosis of infection by VT+ E. coli O157.
Asunto(s)
Anticuerpos Antibacterianos/análisis , Colitis/inmunología , Infecciones por Escherichia coli/inmunología , Escherichia coli/inmunología , Hemorragia Gastrointestinal/inmunología , Pruebas de Aglutinación , Animales , Anticuerpos Antibacterianos/sangre , Toxinas Bacterianas/biosíntesis , Estudios de Casos y Controles , Reacciones Cruzadas , Escherichia coli/patogenicidad , Heces/química , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Inmunoglobulina A Secretora/análisis , Pruebas de Neutralización , Toxina Shiga I , Células VeroRESUMEN
In May-June 1992 cases of infection with verocytotoxin-producing (VT+) Escherichia coli O157 in South Yorkshire could have been associated with prior consumption of beef from a local abattoir. During investigation of the abattoir, bovine rectal swabs and samples of meat and surface swabs from beef carcasses were examined for E. coli O157, isolates of which were tested for toxigenicity, plasmid content and phage type. E. coli O157 was isolated from 84 (4%) of 2103 bovine rectal swabs; of these 84, 78 (93%) were VT+, the most common phage types being 2 and 8, the types implicated in the cluster of human cases. Positive cattle were from diverse sources within England. E. coli O157 was isolated from 7 (30%) of 23 carcasses of rectal swab-positive cattle and from 2 (8%) of 25 carcasses of rectal swab-negative cattle. The study has shown that cattle may be a reservoir of VT+ E. coli O157, and that contamination of carcasses during slaughter and processing may be how beef and beef products become contaminated and thereby transmit the organism to man.
Asunto(s)
Toxinas Bacterianas/biosíntesis , Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/aislamiento & purificación , Carne/microbiología , Mataderos , Animales , Toxinas Bacterianas/genética , Secuencia de Bases , Portador Sano/microbiología , Portador Sano/veterinaria , Bovinos , Citotoxinas/biosíntesis , Citotoxinas/genética , Cartilla de ADN/química , Reservorios de Enfermedades , Enterotoxinas/biosíntesis , Enterotoxinas/genética , Escherichia coli/genética , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/transmisión , Heces/microbiología , Femenino , Microbiología de Alimentos , Humanos , Masculino , Datos de Secuencia Molecular , Toxina Shiga IRESUMEN
Potassium tellurite was assessed for the selection of verocytotoxigenic (VT+) Escherichia coli O157. MICs were higher for VT+ E. coli O157 than for other strains of E. coli and for Aeromonas spp. MacConkey medium containing sorbitol, tellurite and cefixime (TC-SMAC) permitted the growth of VT+ E. coli O157 and Shigella sonnei but partially or completely inhibited the growth of 67% of other strains of E. coli and all or most strains of other sorbitol-non-fermenting species tested. Of 391 rectal swabs from cattle screened on TC-SMAC medium, 26 yielded isolates of VT+ E. coli O157 whereas sorbitol-MacConkey medium with cefixime and rhamnose yielded only nine isolates. Inclusion of potassium tellurite in sorbitol-MacConkey agar markedly increased the rate of isolation of VT+ E. coli O157 from cattle rectal swabs and may do so for other types of specimen.
Asunto(s)
Toxinas Bacterianas/biosíntesis , Citotoxinas/biosíntesis , Escherichia coli/aislamiento & purificación , Telurio , Animales , Bovinos , Medios de Cultivo , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Heces/microbiología , Humanos , Toxina Shiga I , Telurio/farmacologíaAsunto(s)
Toxinas Bacterianas/biosíntesis , Enfermedades de los Bovinos/microbiología , Enterotoxinas/biosíntesis , Infecciones por Escherichia coli/veterinaria , Escherichia coli/metabolismo , Animales , Bovinos , Reservorios de Enfermedades/veterinaria , Infecciones por Escherichia coli/microbiología , EscociaRESUMEN
AIMS: To evaluate a commercially available enzyme immunoassay based on a monoclonal antibody to a genus specific Cryptosporidium (IDEIA Cryptosporidium; Dako) antigen for detecting Cryptosporidium oocysts in faecal and environmental samples. METHODS: 435 human faecal samples and post-filtration deposits from 10 reservoir samples, and from six tap water samples seeded with Cryptosporidium oocysts, were examined by EIA according to the manufacturer's instructions, and by microscopic examination of phenolauramine stained smears. Samples giving discrepant results were examined by specific immunofluorescence, before and after concentration of oocysts. RESULTS: Sixteen (3.6%) faecal samples were positive by both microscopy and EIA; five (1.1%) were positive by microscopy of auramine-phenol stained smears (but were not confirmed by specific immunofluorescence) and negative by EIA; one (0.2%) was positive by EIA alone, but confirmed by specific immunofluorescence; and 362 (83.2%) were negative by both microscopy and EIA. Compared with immunofluorescence positive faecal samples, the sensitivity of conventional microscopy and EIA were 94% and 100%, and specificity 76.4% and 100%, respectively. Fifty one (11.7%) were not examined by microscopy due to detection of other pathogens in a previous sample from that patient, but were found to be negative by EIA. Ten reservoir water samples (not suspected of being linked to cases of cryptosporidiosis) were negative by both microscopy and EIA. Of six samples of tap water seeded with varying concentrations of Cryptosporidium oocysts, two (10(2) and 10(3) oocysts/l) were positive by both microscopy and EIA, two (10 and 1/l) by EIA alone, and two (0.1/l and unseeded water) were negative by both microscopy and EIA. CONCLUSIONS: The kit is simple and rapid to use and offers a less subjective method than microscopy for detecting Cryptosporidium in faecal samples submitted to a busy diagnostic laboratory.