RESUMEN
A cross-sectional study was conducted to determine the prevalence and characteristics of verocytotoxigenic Escherichia coli (VTEC) on 25 dairy farms each located in Waller field and Carlsen field farming areas in Trinidad. On each selected farm, faecal samples were collected from milking cows, calves and humans; rectal swabs were obtained from pet farm dogs; bulk milk was sampled as well as effluent from the milking parlour. Escherichia coli was isolated from all sources on selective media using standard methods. Isolates of E. coli were subjected to slide agglutination test using E. coli O157 antiserum, vero cell cytotoxicity assay to detect verocytotoxin (VT) and heat labile toxin (LT) production, the polymerase chain reaction (PCR) to detect VT genes, and the dry spot test to screen for E. coli O157 and non-O157 strains. In addition, faecal samples from animal and human sources were tested for VT genes using PCR. Of a total of 933 E. coli isolates tested by the slide test, eight (0.9%) were positive for the O157 strain. The vero cell cytotoxicity assay detected VT-producing strains of E. coli in 16.6%, 14.6%, 3.2% and 7.1% of isolates from cows, calves, farm dogs and humans respectively (P < 0.05; chi(2)). For LT production, the highest frequency was detected amongst isolates of E. coli from calves (10.8%) and the lowest (0.0%) amongst isolates from humans and bulk milk (P < 0.05; chi(2)). Of the 61 VT-producing isolates by vero cell cytotoxicity assay tested by PCR, the VT, LT and eae genes were detected in 62.3%, 4.9% and 1.6% respectively (P < 0.05; chi(2)). Amongst the 45 E. coli isolates that were VT positive (vero cell) or VT-gene positive by PCR, 2.2%, 2.2%, 4.4% and 6.7% belonged to non-O157 strains O91, O111, O103 and O157, respectively, as determined by the Dry spot test. Detection of VTEC strains in milk and dairy animals poses a health risk to consumers of milk originating from these farms. In addition, the demonstration of VTEC strains in humans, VT gene in faecal samples and E. coli isolates as well as non-O157 VTEC strains of E. coli are being documented for the first time in the country.
Asunto(s)
Enfermedades de los Bovinos/epidemiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli , Filogenia , Toxinas Shiga/biosíntesis , Pruebas de Aglutinación , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/transmisión , Chlorocebus aethiops , Estudios Transversales , Industria Lechera/estadística & datos numéricos , Perros , Escherichia coli/clasificación , Escherichia coli/aislamiento & purificación , Escherichia coli/metabolismo , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/transmisión , Heces/microbiología , Femenino , Humanos , Leche/microbiología , Reacción en Cadena de la Polimerasa , Prevalencia , Trinidad y Tobago/epidemiología , Células Vero , ZoonosisRESUMEN
A cross-sectional study was conducted to determine the prevalence and characteristics of verocytotoxigenic Escherichia coli (VTEC) on 25 dairy farms each located in Waller field and Carlsen field farming areas in Trinidad. On each selected farm, faecal samples were collected from milking cows, calves and humans; rectal swabs were obtained from pet farm dogs; bulk milk was sampled as well as effluent from the milking parlour. Escherichia coli was isolated from all sources on selective media using standard methods. Isolates of E. coli were subjected to slide agglutination test using E. coli O157 antiserum, vero cell cytotoxicity assay to detect verocytotoxin (VT) and heat labile toxin (LT) production, the polymerase chain reaction (PCR) to detect VT genes, and the dry spot test to screen for E. coli O157 and non-O157 strains. In addition, faecal samples from animal and human sources were tested for VT genes using PCR. Of a total of 933 E. coli isolates tested by the slide test, eight (0.9 per cent) were positive for the O157 strain. The vero cell cytotoxicity assay detected VT-producing strains of E. coli in 16.6 per cent, 14.6 per cent, 3.2 per cent and 7.1 per cent of isolates from cows, calves, farm dogs and humans respectively (P < 0.05; chi(2)). For LT production, the highest frequency was detected amongst isolates of E. coli from calves (10.8 per cent) and the lowest (0.0 per cent) amongst isolates from humans and bulk milk (P < 0.05; chi(2)). Of the 61 VT-producing isolates by vero cell cytotoxicity assay tested by PCR, the VT, LT and eae genes were detected in 62.3 per cent, 4.9 per cent and 1.6 per cent respectively (P < 0.05; chi(2)). Amongst the 45 E. coli isolates that were VT positive (vero cell) or VT-gene positive by PCR, 2.2 per cent, 2.2 per cent, 4.4 per cent and 6.7 per cent belonged to non-O157 strains O91, O111, O103 and O157, respectively, as determined by the Dry spot test...
Asunto(s)
Animales , Escherichia coli , Industria Lechera , Trinidad y TobagoRESUMEN
The aim of this study was to determine the critical incidents that contribute to the initiation of substance use and abuse among women in Trinidad and Tobago. Twenty women were randomly selected from 46 women currently attending 43 drug rehabilitation centres, Narcotics Anonymous and Alcoholics Anonymous groups in Trinidad and Tobago. In-depth semi-structured interviews using the critical incident technique were conducted. Interviews were recorded, transcribed and analyzed. Concepts, categories and themes were determined by team study and group discussion. The critical incidents that influenced women to initiate the use and abuse of substances fell into eight major themes: factors intrinsic to the individual woman, family factors, social and environmental factors, life stresses, relationship issues, abuse, peer pressure and substance use and abuse as a coping mechanism. The results imply that the factors contributing to the initiation of substance use and abuse among women in Trinidad and Tobago are many and complex. As such any attempt to address this issue requires a broad-based approach. Such an approach should address family use of such substances, societal acceptance of them, availability, the self-esteem of the individual woman and her ability to cope with peer and internal stresses.
Asunto(s)
Trastornos Relacionados con Sustancias/psicología , Adaptación Psicológica , Adulto , Alcoholismo/psicología , Alcoholismo/rehabilitación , Femenino , Humanos , Factores de Riesgo , Factores Socioeconómicos , Estrés Psicológico , Trastornos Relacionados con Sustancias/rehabilitación , Trinidad y TobagoRESUMEN
The aim of this study was to determine the critical incidents that contribute to the initiation of substance use and abuse among women in Trinidad and Tobago. Twenty women were randomly selected from 46 women currently attending 43 drug rehabilitation centres, Narcotics Anonymous and Alcoholics Anonymous groups in Trinidad and Tobago. In-depth semi-structured interviews using the critical incident technique were conducted. Interviews were recorded, transcribed and analyzed. Concepts, categories and themes were determined by team study and group discussion. The critical incidents that influenced women to initiate the use and abuse of substances fell into eight major themes: factors intrinsic to the individual woman, family factors, social and environmental factors, life stresses, relationship issues, abuse, peer pressure and substance use and abuse as a coping mechanism. The results imply that the factors contributing to the initiation of substance use and abuse among women in Trinidad and Tobago are many and complex. As such any attempt to address this issue requires a broad-based approach. Such an approach should address family use of such substances, societal acceptance of them, availability, the self-esteem of the individual woman and her ability to cope with peer and internal stresses
El objetivo de este estudio era determinar los incidentes críticos que contribuyen a la iniciación en el uso yabuso de substancias entre las mujeres en Trinidad y Tobago. Se seleccionaron veinte mujeres al azar, de46 mujeres que asistían a 43 centros de rehabilitación de drogas, grupos de Alcohólicos Anónimos, y Narcóticos Anónimos en Trinidad y Tobago. Se realizaron entrevistas profundas semi- structuradas usando la técnica de incidentes críticos. Las entrevistas fueron grabadas, transcriptas, y analizadas. Los conceptos, categorías y temas fueron determinados mediante estudio en equipo y discusión en grupos. Los incidentes críticos que influyeron en que las mujeres se iniciaran en el uso y abuso de substancias comprendían ocho temas principales: factores intrínsecos a la mujer como individuo, factores familiares, factores sociales y medioambientales, estreses cotidianos, problemas en las relaciones, abusos, influencia de los amigos y malas compañías, y el uso y abuso de sustancias como mecanismo para hacer frente al estrés. Los resultados implican que los factores que contribuyen a la iniciación del uso y abuso de sustancias entre las mujeres de Trinidad y Tobago son muchos y complejos. Siendo así, cualquier intento por abordar este problema requiere un enfoque amplio. Tal enfoque debe abordar el uso de substancias por parte de la familia, la aceptación social de las substancias, la disponibilidad, la autoestima de la mujer como individuo y su capacidad para hacer frente tanto a su estrés interno como al que proviene de la presión que ejercen amigos y malas compañías.
Asunto(s)
Humanos , Femenino , Adulto , Trastornos Relacionados con Sustancias/psicología , Adaptación Psicológica , Alcoholismo/psicología , Alcoholismo/rehabilitación , Estrés Psicológico , Factores Socioeconómicos , Factores de Riesgo , Trastornos Relacionados con Sustancias/rehabilitación , Trinidad y TobagoRESUMEN
We report on the construction of a novel strain of E. coli that can be useful for studies on the structure/function relationship of 5S rRNAs. The bacterial strain is deficient in six of the eight naturally occurring 5S rRNA genes (operons B, D, H, G, E) and demonstrates a greatly reduced growth rate that can be compensated by the plasmid-encoded expression of 5S rRNA. The relatively large difference in growth rate between compensated and non-compensated mutants provides the basis for a quick and simple assaying system for both the evaluation and mass screening of divergent 5S rRNA sequences for function. We describe the construction of the 5S rRNA deletion mutant BDHGE and characterize the usefulness and limitations of the system for evaluating structure/function relationships of 5S rRNA sequence.
Asunto(s)
Escherichia coli/genética , Genes de ARNr , ARN Bacteriano/genética , ARN Ribosómico 5S/genética , Escherichia coli/crecimiento & desarrollo , Eliminación de Gen , Operón de ARNrRESUMEN
Herein we present the first evidence for the presence of Paralytic Shellfish Poison (PSP) in Trinidadian waters. The toxin was found in a meat extract of the mussel, Perna viridis. PSP has not previously been demonstrated in the shellfish of Caribbean islands. The presence of PSP in Trinidad is therefore significant in that it presents an opportunity to better understand the dynamics of PSP and algal blooms in both a region and island environment not normally associated with PSP.P. viridis is not native to Trinidad, but rather originates from eastern Asia. It presented itself only recently in Trinidadian waters. Interestingly, shellfish consumption and algal blooms have had a long history of coexistence in Trinidad without any record of human intoxications. In this context, potential Public Health implications of finding PSP in a non-native shellfish species are briefly discussed.
Asunto(s)
Ratones , Ratas , Humanos , Intoxicación , Mariscos , Bivalvos , Trinidad y TobagoRESUMEN
Herein we present the first evidence for the presence of Paralytic Shellfish Poison (PSP) in Trinidadian waters. The toxin was found in a meat extract of the mussel, Perna viridis. PSP has not previously been demonstrated in the shellfish of Caribbean islands. The presence of PSP in Trinidad is therefore significant in that it presents an opportunity to better understand the dynamics of PSP and algal blooms in both a region and island environment not normally associated with PSP.P. viridis is not native to Trinidad, but rather originates from eastern Asia. It presented itself only recently in Trinidadian waters. Interestingly, shellfish consumption and algal blooms have had a long history of coexistence in Trinidad without any record of human intoxications. In this context, potential Public Health implications of finding PSP in a non-native shellfish species are briefly discussed.
Asunto(s)
Bivalvos/química , Toxinas Marinas/análisis , Animales , Toxinas Marinas/toxicidad , Ratones , Ratas , Estándares de Referencia , Saxitoxina/toxicidad , Trinidad y TobagoRESUMEN
In Escherichia coli, ribosomal RNAs (16S, 23S and 5S) are co-transcribed in a highly regulated manner from seven genomically dispersed operons. Previous studies on the cellular effects of altered levels of two of these rRNAs (16S and 23S) have been useful in better understanding the regulation of rRNA expression. Furthering these studies, we have investigated the effect of 5S rRNA deficiencies on cell fitness through the sequential deletion of 5S rRNA genes. Our findings indicate that the loss of 5S rDNA from multiple genes decreases cell fitness more rapidly than loss of a similar number of 16S and 23S rRNA genes. These results suggest that the cell's innate ability to up-regulate rRNA operons does not compensate for 5S rRNA deficiencies, as was previously shown for 16S and 23S rRNAs. A plasmid-borne 5S rRNA gene is able to compensate for the deleted 5S rRNA genes.
Asunto(s)
Escherichia coli/crecimiento & desarrollo , Escherichia coli/genética , Eliminación de Gen , Genes de ARNr , ARN Ribosómico 5S/genética , Dosificación de Gen , Prueba de Complementación Genética , Operón , Plásmidos/genética , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Análisis de Secuencia de ADNRESUMEN
Contamination of the environment with human sewage represents a serious public health concern in which Escherichia coli plays a central role, either directly as a human pathogen or indirectly through its use as an indicator organism. There is thus an ongoing effort to better understand the behavior of E. coli within such environments. Useful to such studies is the ability to readily detect a specific E. coli population and distinguish it from similar indigenous bacteria. Herein, we report the construction of an E. coli strain (PCPHR) that expresses a Stable Artificial RNA (SAR) from the chromosomal rrnH operon. The SAR product is present in large numbers of copies/cell and thus provides an enhanced detection signal without significant effect on the wild-type growth rate. Detection can be accomplished by any of several routine molecular methods. Preliminary studies suggest SAR expression levels correlate positively with growth. PCPHR is immediately available for use as a marker strain for E. coli in application in the arena of public health or environmental studies.