Encuesta nacional sobre cambios en las políticas de comunicación, visitas y cuidados al final de la vida en las unidades de cuidados intensivos durante las diferentes olas de la pandemia de COVID-19 (estudio COVIFAUCI) / National survey on changes in visitation, communication and end-of-life care policies in intensive care units through the different COVID-19 pandemic's waves (COVIFAUCI study)

Introducción La pandemia derivada de la infección por SARS-CoV-2 propició cambios en los cuidados tanto a familiares como a pacientes de cuidados intensivos durante las diferentes olas de incidencia del virus. La línea de humanización seguida por la mayoría de los hospitales se vio gravemente afectada por las restricciones aplicadas. Como objetivo, planteamos conocer las modificaciones experimentadas durante las diferentes olas de la pandemia por SARS-CoV-2 en España respecto a la política de visitas a los pacientes en UCI, el acompañamiento al final de la vida, y el uso de las nuevas tecnologías de la comunicación entre familiares, pacientes y profesionales. Métodos Estudio descriptivo transversal multicéntrico mediante encuesta a las UCI españolas desde febrero a abril de 2022. Se realizaron métodos de análisis estadísticos a los resultados según lo apropiado. El estudio fue avalado por la Sociedad Española de Enfermería Intensiva y Unidades Coronarias. Resultados Respondieron un 29% de las unidades contactadas. Los minutos de visita diarios de los familiares se redujeron drásticamente de 135 (87,5-255) a 45 (25-60) en el 21,2% de las unidades que permitían su acceso, mejorando levemente con el paso de las olas. En el caso de duelo, la permisividad fue mayor, aumentando el uso de las nuevas tecnologías para la comunicación paciente-familia en el caso del 96,5% de las unidades. Conclusiones Las familias de los pacientes ingresados en UCI durante las diferentes olas de la pandemia por COVID-19 han experimentado restricciones en las visitas y cambio de la presencialidad por técnicas virtuales de comunicación. Los tiempos de acceso se redujeron a niveles mínimos durante la primera ola, recuperándose con el avance de la pandemia pero sin llegar nunca a los niveles iniciales... (AU)

Introduction The pandemic derived from the SARS-CoV-2 infection led to changes in care for both relatives and intensive care patients during the different waves of incidence of the virus. The line of humanization followed by the majority of the hospitals was seriously affected by the restrictions applied. As an objective, we propose to know the modifications suffered during the different waves of the SARS-CoV-2 pandemic in Spain regarding the policy of visits to patients in the ICU, monitoring at the end of life, and the use of new technologies of communication between family members, patients and professionals. Methods Multicenter cross-sectional descriptive study through a survey of Spanish ICUs from February to April 2022. Statistical analysis methods were performed on the results as appropriate. The study was endorsed by the Spanish Society of Intensive Nursing and Coronary Units. Results Twenty-nine percent of the units contacted responded. The daily visiting minutes of relatives dropped drastically from 135 (87.5-255) to 45 (25-60) in the 21.2% of units that allowed their access, improving slightly with the passing of the waves. In the case of bereavement, the permissiveness was greater, increasing the use of new technologies for patient-family communication in the case of 96.5% of the units. Conclusions The family of patients admitted to the ICU during the different waves of the COVID-19 pandemic have suffered restrictions on visits and a change from face-to-face to virtual communication techniques. Access times were reduced to minimum levels during the first wave, recovering with the advance of the pandemic but never reaching initial levels. Despite the implemented solutions and virtual communication, efforts should be directed towards improving the protocols for the humanization of healthcare that allow caring for families and patients whatever the healthcare context. (AU)

Monitorización de la glucemia en el paciente crítico adulto: tipo de muestra y método de análisis. Revisión sistemática y metanálisis / Blood glucose monitoring in critically ill adult patients: Type of sample and method of analysis. Systematic review and meta-analysis

IntroducciónLa guía clínica para el manejo de la sepsis recomienda usar muestras de sangre arterial para el control glucémico. Un estudio multicéntrico en 86 unidades de cuidados intensivos españolas reveló que el 85,4% de estas utilizaban punción capilar.ObjetivoAnalizar la fiabilidad de la glucemia comparando diferentes muestras sanguíneas (arterial, venosa, capilar) e instrumentos (glucómetros, gasómetros, laboratorio central). Secundariamente, estimar el efecto de variables confusoras y el rendimiento de los instrumentos de medición determinados por las diferentes normas de calidad.MetodologíaRevisión sistemática y metanálisis con búsqueda en las bases de datos PubMed, CINAHL y Embase en septiembre-2021 y septiembre-2022, sin límites temporales ni idiomáticos. Fuentes de literatura gris: DART-Europe, OpenGrey y Google Académico. Resultados resumidos mediante síntesis cualitativa (descripción de resultados, características de los estudios) y cuantitativa (metanálisis para evaluar la diferencia de medias estandarizadas). Calidad metodológica de artículos evaluada con Quality Assessment of Diagnostic Accuracy Studies-2. Protocolo: https://osf.io/ DOI 10.17605/OSF.IO/T8KYP.ResultadosSe incluyeron un total de 32 artículos y 5.451 pacientes. No se obtuvieron discrepancias entre muestras arteriales con glucómetro vs. laboratorio (sesgo [IC95%]: 0,01 [−0,12 a 0,14] mg/dL). En cambio, muestras arteriales con gasómetro sí sobreestimaron de forma significativa (sesgo [IC95%]: 0,12 [0,01 a 0,24] mg/dL). La misma tendencia presentan capilares con glucómetro, aunque no de forma significativa (sesgo [IC95%]: 0,07 [−0,02 a 0,15] mg/dL). Hay discrepancia entre los estudios sobre el efecto del hematocrito y el equilibrio ácido-base. El mayor consenso se da en la poca concordancia del glucómetro con muestras capilares vs. laboratorio en presencia de shock y soporte vasopresor, situación de fallo renal o durante el tratamiento con vitamina C.Conclusiones... (AU)

IntroductionThe clinical guideline for the management of sepsis recommends using arterial blood samples for glycaemic control. A multicentre study in 86 Spanish intensive care units revealed that 85.4% of these used capillary puncture.ObjectiveTo analyse the reliability of glycaemia by comparing different blood samples (arterial, venous, capillary) and instruments (glucometers, gasometers, central laboratory). Secondarily, to estimate the effect of confounding variables and the performance of measuring instruments as determined by different quality standards.MethodologySystematic review and meta-analysis with search in PubMed, CINAHL and Embase databases in September-2021 and September-2022, with no time or language limits. Grey literature sources: DART-Europe, OpenGrey and Google Scholar. Results summarised by qualitative (description of results, study characteristics) and quantitative (meta-analysis to assess standardised mean difference) synthesis. Methodological quality of articles assessed with Quality Assessment of Diagnostic Accuracy Studies-2. Protocol: https://osf.io/ DOI 10.17605/OSF.IO/T8KYP.ResultsA total of 32 articles and 5451 patients were included. No discrepancies were obtained between arterial glucometer vs. laboratory samples (bias [95%CI]: 0.01 [−0.12 to 0.14] mg/dL). In contrast, arterial samples with a gasometer did significantly overestimate (bias [95%CI]: 0.12 [0.01 to 0.24] mg/dL). The same trend is seen in capillaries with a glucometer, although not significantly (bias [95%CI]: 0.07 [−0.02 to 0.15] mg/dL). There is discrepancy between studies on the effect of haematocrit and acid-base balance. The greatest consensus is on the poor agreement of glucometer with capillary vs. laboratory samples in the presence of shock and vasopressor support, renal failure or during vitamin C treatment.Conclusions... (AU)

Encuesta nacional sobre cambios en las políticas de comunicación, visitas y cuidados al final de la vida en las unidades de cuidados intensivos durante las diferentes olas de la pandemia de COVID-19 (estudio COVIFAUCI) / National survey on changes in visitation, communication and end-of-life care policies in intensive care units through the different COVID-19 pandemic's waves (COVIFAUCI study)

Introducción La pandemia derivada de la infección por SARS-CoV-2 propició cambios en los cuidados tanto a familiares como a pacientes de cuidados intensivos durante las diferentes olas de incidencia del virus. La línea de humanización seguida por la mayoría de los hospitales se vio gravemente afectada por las restricciones aplicadas. Como objetivo, planteamos conocer las modificaciones experimentadas durante las diferentes olas de la pandemia por SARS-CoV-2 en España respecto a la política de visitas a los pacientes en UCI, el acompañamiento al final de la vida, y el uso de las nuevas tecnologías de la comunicación entre familiares, pacientes y profesionales. Métodos Estudio descriptivo transversal multicéntrico mediante encuesta a las UCI españolas desde febrero a abril de 2022. Se realizaron métodos de análisis estadísticos a los resultados según lo apropiado. El estudio fue avalado por la Sociedad Española de Enfermería Intensiva y Unidades Coronarias. Resultados Respondieron un 29% de las unidades contactadas. Los minutos de visita diarios de los familiares se redujeron drásticamente de 135 (87,5-255) a 45 (25-60) en el 21,2% de las unidades que permitían su acceso, mejorando levemente con el paso de las olas. En el caso de duelo, la permisividad fue mayor, aumentando el uso de las nuevas tecnologías para la comunicación paciente-familia en el caso del 96,5% de las unidades. Conclusiones Las familias de los pacientes ingresados en UCI durante las diferentes olas de la pandemia por COVID-19 han experimentado restricciones en las visitas y cambio de la presencialidad por técnicas virtuales de comunicación. Los tiempos de acceso se redujeron a niveles mínimos durante la primera ola, recuperándose con el avance de la pandemia pero sin llegar nunca a los niveles iniciales... (AU)

Introduction The pandemic derived from the SARS-CoV-2 infection led to changes in care for both relatives and intensive care patients during the different waves of incidence of the virus. The line of humanization followed by the majority of the hospitals was seriously affected by the restrictions applied. As an objective, we propose to know the modifications suffered during the different waves of the SARS-CoV-2 pandemic in Spain regarding the policy of visits to patients in the ICU, monitoring at the end of life, and the use of new technologies of communication between family members, patients and professionals. Methods Multicenter cross-sectional descriptive study through a survey of Spanish ICUs from February to April 2022. Statistical analysis methods were performed on the results as appropriate. The study was endorsed by the Spanish Society of Intensive Nursing and Coronary Units. Results Twenty-nine percent of the units contacted responded. The daily visiting minutes of relatives dropped drastically from 135 (87.5-255) to 45 (25-60) in the 21.2% of units that allowed their access, improving slightly with the passing of the waves. In the case of bereavement, the permissiveness was greater, increasing the use of new technologies for patient-family communication in the case of 96.5% of the units. Conclusions The family of patients admitted to the ICU during the different waves of the COVID-19 pandemic have suffered restrictions on visits and a change from face-to-face to virtual communication techniques. Access times were reduced to minimum levels during the first wave, recovering with the advance of the pandemic but never reaching initial levels. Despite the implemented solutions and virtual communication, efforts should be directed towards improving the protocols for the humanization of healthcare that allow caring for families and patients whatever the healthcare context. (AU)

Monitorización de la glucemia en el paciente crítico adulto: tipo de muestra y método de análisis. Revisión sistemática y metanálisis / Blood glucose monitoring in critically ill adult patients: Type of sample and method of analysis. Systematic review and meta-analysis

IntroducciónLa guía clínica para el manejo de la sepsis recomienda usar muestras de sangre arterial para el control glucémico. Un estudio multicéntrico en 86 unidades de cuidados intensivos españolas reveló que el 85,4% de estas utilizaban punción capilar.ObjetivoAnalizar la fiabilidad de la glucemia comparando diferentes muestras sanguíneas (arterial, venosa, capilar) e instrumentos (glucómetros, gasómetros, laboratorio central). Secundariamente, estimar el efecto de variables confusoras y el rendimiento de los instrumentos de medición determinados por las diferentes normas de calidad.MetodologíaRevisión sistemática y metanálisis con búsqueda en las bases de datos PubMed, CINAHL y Embase en septiembre-2021 y septiembre-2022, sin límites temporales ni idiomáticos. Fuentes de literatura gris: DART-Europe, OpenGrey y Google Académico. Resultados resumidos mediante síntesis cualitativa (descripción de resultados, características de los estudios) y cuantitativa (metanálisis para evaluar la diferencia de medias estandarizadas). Calidad metodológica de artículos evaluada con Quality Assessment of Diagnostic Accuracy Studies-2. Protocolo: https://osf.io/ DOI 10.17605/OSF.IO/T8KYP.ResultadosSe incluyeron un total de 32 artículos y 5.451 pacientes. No se obtuvieron discrepancias entre muestras arteriales con glucómetro vs. laboratorio (sesgo [IC95%]: 0,01 [−0,12 a 0,14] mg/dL). En cambio, muestras arteriales con gasómetro sí sobreestimaron de forma significativa (sesgo [IC95%]: 0,12 [0,01 a 0,24] mg/dL). La misma tendencia presentan capilares con glucómetro, aunque no de forma significativa (sesgo [IC95%]: 0,07 [−0,02 a 0,15] mg/dL). Hay discrepancia entre los estudios sobre el efecto del hematocrito y el equilibrio ácido-base. El mayor consenso se da en la poca concordancia del glucómetro con muestras capilares vs. laboratorio en presencia de shock y soporte vasopresor, situación de fallo renal o durante el tratamiento con vitamina C.Conclusiones... (AU)

IntroductionThe clinical guideline for the management of sepsis recommends using arterial blood samples for glycaemic control. A multicentre study in 86 Spanish intensive care units revealed that 85.4% of these used capillary puncture.ObjectiveTo analyse the reliability of glycaemia by comparing different blood samples (arterial, venous, capillary) and instruments (glucometers, gasometers, central laboratory). Secondarily, to estimate the effect of confounding variables and the performance of measuring instruments as determined by different quality standards.MethodologySystematic review and meta-analysis with search in PubMed, CINAHL and Embase databases in September-2021 and September-2022, with no time or language limits. Grey literature sources: DART-Europe, OpenGrey and Google Scholar. Results summarised by qualitative (description of results, study characteristics) and quantitative (meta-analysis to assess standardised mean difference) synthesis. Methodological quality of articles assessed with Quality Assessment of Diagnostic Accuracy Studies-2. Protocol: https://osf.io/ DOI 10.17605/OSF.IO/T8KYP.ResultsA total of 32 articles and 5451 patients were included. No discrepancies were obtained between arterial glucometer vs. laboratory samples (bias [95%CI]: 0.01 [−0.12 to 0.14] mg/dL). In contrast, arterial samples with a gasometer did significantly overestimate (bias [95%CI]: 0.12 [0.01 to 0.24] mg/dL). The same trend is seen in capillaries with a glucometer, although not significantly (bias [95%CI]: 0.07 [−0.02 to 0.15] mg/dL). There is discrepancy between studies on the effect of haematocrit and acid-base balance. The greatest consensus is on the poor agreement of glucometer with capillary vs. laboratory samples in the presence of shock and vasopressor support, renal failure or during vitamin C treatment.Conclusions... (AU)

Blood glucose monitoring in critically ill adult patients: type of sample and method of analysis. Systematic review and meta-analysis.

INTRODUCTION: The clinical guideline for the management of sepsis, recommends using arterial blood samples for glycaemic control. A multicentre study in 86 Spanish intensive care units (ICU) revealed that 85.4% of ICUs used capillary puncture. OBJECTIVE: To analyse the reliability of glycaemia by comparing different blood samples (arterial, venous, capillary) and instruments (glucometers, gasometers, central laboratory). Secondarily, to estimate the effect of confounding variables and the performance of measuring instruments as determined by different quality standards. METHODOLOGY: Systematic review and meta-analysis with search in PubMed, CINAHL and Embase databases in September-2021 and September-2022, with no time or language limits. Grey literature sources: DART-Europe, OpenGrey and Google Scholar. Results summarised by qualitative (description of results, study characteristics) and quantitative (meta-analysis to assess standardised mean difference) synthesis. Methodological quality of articles assessed with Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). PROTOCOL: https://osf.io/ DOI 10.17605/OSF.IO/T8KYP. RESULTS: A total of 32 articles and 5451 patients were included. No discrepancies were obtained between arterial glucometer vs laboratory samples [bias (95%CI): 0.01 (-0.12 to 0.14) mg/dL]. In contrast, arterial samples with a gasometer did significantly overestimate [bias (95%CI): 0.12 (0.01 to 0.24) mg/dL]. The same trend is seen in capillaries with a glucometer, although not significantly [bias (95%CI): 0.07 (--0.02 to 0.15) mg/dL]. There is discrepancy between studies on the effect of haematocrit and acid-base balance. The greatest consensus is on the poor agreement of glucometer with capillary vs laboratory samples in the presence of shock and vasopressor support, renal failure or during vitamin C treatment. CONCLUSIONS: The evidence to date recommends the use of arterial blood with a blood glucose meter for better reliability of glycaemic analysis and less effect of possible confounding variables, frequently present in the critically ill adult patient.

National survey on changes in visitation, communication and end-of-life care policies in intensive care units through the different COVID-19 pandemic's waves (COVIFAUCI study).

INTRODUCTION: The pandemic derived from the SARS-CoV-2 infection led to changes in care for both relatives and intensive care patients during the different waves of incidence of the virus. The line of humanization followed by the majority of the hospitals was seriously affected by the restrictions applied. As an objective, we propose to know the modifications suffered during the different waves of the SARS-CoV-2 pandemic in Spain regarding the policy of visits to patients in the ICU, monitoring at the end of life, and the use of new technologies. of communication between family members, patients and professionals. METHODS: Multicenter cross-sectional descriptive study through a survey of Spanish ICUs from February to April 2022. Statistical analysis methods were performed on the results as appropriate. The study was endorsed by the Spanish Society of Intensive Nursing and Coronary Units. RESULTS: 29% of the units contacted responded. The daily visiting minutes of relatives dropped drastically from 135 (87.5-255) to 45 (25-60) in the 21.2% of units that allowed their access, improving slightly with the passing of the waves. In the case of bereavement, the permissiveness was greater, increasing the use of new technologies for patient-family communication in the case of 96.5% of the units. CONCLUSIONS: The family of patients admitted to the ICU during the different waves of the COVID-19 pandemic have suffered restrictions on visits and a change from face-to-face to virtual communication techniques. Access times were reduced to minimum levels during the first wave, recovering with the advance of the pandemic but never reaching initial levels. Despite the implemented solutions and virtual communication, efforts should be directed towards improving the protocols for the humanization of healthcare that allow caring for families and patients whatever the healthcare context.

Effectiveness of closed blood sampling systems in intensive care patients: a scoping review.

BACKGROUND: Anemia associated with blood extraction for diagnostic purposes is a highly prevalent entity in intensive care units (ICU) for adults. The evidence recommends its prevention through different strategies, among which we can find the use of closed blood sampling systems (CBSS). Different experimental studies support the use of these devices. OBJECTIVE: To identify knowledge gaps regarding the effectiveness of CBSS in ICU patients. METHODS: Scoping review with search in PubMed, CINAHL, Embase, Cochrane Library and Joanna Briggs Institute databases, between September-2021 and September-2022. No time, language, or other limits were applied to ensure the recovery of all relevant studies. Gray literature sources: DART-Europe, OpenGrey and Google Scholar. Two researchers independently reviewed titles and abstracts and assessed full texts against the inclusion criteria. The following data was extracted for each study: design and sample, inclusion and exclusion criteria, variables, type of CBSS, results and conclusions. RESULTS: 18 articles were included in the final review, 11 clinical trials (RCTs) published between 1992 and 2014. Three systematic reviews were found, but they only analyzed the effect of CBSS in reducing blood loss, hemoglobin stabilization, and the need for transfusion. Five of the RCTs analyzed the risk of infection, one catheter complications, and two alterations in blood pressure readings. CONCLUSIONS: The use of CBSS is recommended to reduce blood loss in ICUs. However, there are discrepancies about their ability to prevent anemia and/or the need for blood transfusion. Its use does not increase catheter-related infection rates or alter the measurement of mean arterial pressure.

Relación entre función y volumen renal en la poliquistosis renal autosómica dominante: estudio transversal / Relationship between renal function and renal volume in autosomal dominant polycystic kidney disease: cross-sectional study

Objetivo. Determinar en pacientes con poliquistosis renal autosómica dominante la relación entre el volumen renal total (suma de ambos riñones, VRT) medido con resonancia magnética y la función renal; y su comportamiento según el sexo y la presencia de hipertensión arterial, hipercolesterolemia e hiperuricemia. Método. Estudio transversal en el que se incluyen pacientes con poliquistosis renal autosómica dominante que realizan revisiones periódicas en las consultas externas de Nefrología del Hospital Virgen de las Nieves de Granada, a quienes entre enero de 2008 y marzo de 2011 se les realizó una resonancia magnética para estimar el volumen renal. Resultados. Se evaluaron 67 pacientes (59,7% mujeres, edad media 48±14,4 años). Encontramos asociación positiva significativa entre VRT y creatinina sérica o urea, que resultó inversa frente al filtrado glomerular estimado por MDRD-4 y Cockcroft-Gault. Las mujeres mostraron un nivel medio de creatinina sérica y VRT inferior respecto al varón de forma significativa. Los subgrupos afectos de hipertensión arterial e hiperuricemia mostraron valores medios de creatinina sérica, urea y VRT más altos y filtrados glomerulares estimados inferiores. El subgrupo con hipercolesterolemia mostró valores medios de urea más altos y filtrados glomerulares estimados inferiores sin detectarse diferencias significativas respecto al VRT. Conclusión. El volumen de los riñones poliquísticos medido por resonancia magnética se asocia con la función renal, y puede ser útil como estudio complementario para monitorizar la progresión de la enfermedad. La presencia de hipertensión arterial, hiperuricemia o hipercolesterolemia están asociados a una peor función renal (AU)

Objective. To determine in patients with autosomal dominant polycystic kidney disease the relationship between total renal volume (the sum of both kidneys, TRV) as measured by magnetic resonance and renal function; and its behaviour according to sex and the presence of arterial hypertension, hypercholesterolaemia and hyperglycemia. Method. Cross-sectional study including patients with autosomal dominant polycystic kidney disease who underwent periodic reviews at Nephrology external consultations at Hospital de las Nieves de Granada, and who underwent an magnetic resonance to estimate renal volume between January 2008 and March 2011. Results. We evaluated 67 patients (59.7% women, average age of 48±14.4 years) and found a significant positive association between TRV and serum creatinine or urea, which was reversed compared with estimated glomerular filtration by MDRD-4 and Cockcroft-Gault. Women showed an average serum creatinine level and a significantly lower TRV level compared with males. Subgroups affected by arterial hypertension and hyperuricemia presented average values for serum creatinine and urea, higher for TRV and lower for estimated glomerular filtration. The hypercholesterolaemia subgroup showed higher average values for urea and lower for estimated glomerular filtration, without detecting significant differences compared with TRV. Conclusion. The volume of polycystic kidneys measured by magnetic resonance is associated with renal function, and can be useful as a complementary study to monitor disease progression. The presence of arterial hypertension, hyperuricemia or hypercholesterolaemia is associated with a poorer renal function (AU)

Relationship between renal function and renal volume in autosomal dominant polycystic kidney disease: cross-sectional study.

OBJECTIVE: To determine in patients with autosomal dominant polycystic kidney disease the relationship between total renal volume (the sum of both kidneys, TRV) as measured by magnetic resonance and renal function; and its behaviour according to sex and the presence of arterial hypertension, hypercholesterolaemia and hyperglycemia. METHOD: Cross-sectional study including patients with autosomal dominant polycystic kidney disease who underwent periodic reviews at Nephrology external consultations at Hospital de las Nieves de Granada, and who underwent an magnetic resonance to estimate renal volume between January 2008 and March 2011. RESULTS: We evaluated 67 patients (59.7% women, average age of 48±14.4 years) and found a significant positive association between TRV and serum creatinine or urea, which was reversed compared with estimated glomerular filtration by MDRD-4 and Cockcroft-Gault. Women showed an average serum creatinine level and a significantly lower TRV level compared with males. Subgroups affected by arterial hypertension and hyperuricemia presented average values for serum creatinine and urea, higher for TRV and lower for estimated glomerular filtration. The hypercholesterolaemia subgroup showed higher average values for urea and lower for estimated glomerular filtration, without detecting significant differences compared with TRV. CONCLUSION: The volume of polycystic kidneys measured by magnetic resonance is associated with renal function, and can be useful as a complementary study to monitor disease progression. The presence of arterial hypertension, hyperuricemia or hypercholesterolaemia is associated with a poorer renal function.

Isolation of cryptic plasmids from moderately halophilic eubacteria of the genus Halomonas. Characterization of a small plasmid from H. elongata and its use for shuttle vector construction.

Three cryptic plasmids have been isolated from moderately halophilic eubacteria belonging to three species of the genus Halomonas. These three plasmids were designated pHE1 (4.2 kb, isolated from H. elongata ATCC 33174), pHI1 (48 kb, isolated from "H. israelensis" ATCC 43985), and pHS1 (ca. 70 kb, isolated from H. subglaciescola UQM 2927). Because of its small size, the plasmid pHE1 was selected for further characterization and construction of a shuttle vector for Halomonas strains. pHE1 was cloned into pBluescript KS and a detailed restriction map was constructed. Hybridization experiments excluded the existence of sequences homologous to pHE1 in total DNA from other strains of the genus Halomonas. Moreover, no DNA homology with pMH1, the only plasmid described so far from moderate halophiles, was found. Since pHE1 appeared to be unable to replicate in Escherichia coli cells, a number of mobilizable pHE1-derived hybrid plasmids were constructed that could be selected and maintained both in E. coli and in H. elongata. Finally, an improved shuttle vector, pHS15, was generated. The vector pHS15 contains an origin of replication from E. coli as well as one from H. elongata, a streptomycin resistance gene for positive selection in moderate halophiles, a number of unique restriction sites commonly used for cloning, and the mobilization functions of the broad host range IncP plasmid RK2. The vector pHS15 was readily mobilized by the RK2 derivative pRK2013 to all Halomonas strains tested so far. This is the first report on the development of a cloning vector useful for moderately halophilic eubacteria.

Characterization of a plasmid from moderately halophilic eubacteria.

A plasmid has been isolated for the first time from moderately halophilic eubacteria. Halomonas elongata, Halomonas halmophila, Deleya halophila and Vibrio costicola were found to harbour an 11.5 kbp plasmid (pMH1). The plasmid was isolated and characterized after transformation into Escherichia coli JM101 cells. A restriction map was constructed, and unique restriction sites for EcoRI, EcoRV and ClaI were detected. The occurrence of such a plasmid in the original halophilic strains was confirmed by Southern hybridization. The plasmid carries genetic determinants that mediate resistance to kanamycin, tetracycline, and neomycin. This property, together with its relatively small size, its stability in E. coli cells, and the presence of unique restriction sites, makes pMH1 a good candidate for the development of a cloning vector for moderate halophiles.

Survey of metal tolerance in moderately halophilic eubacteria.

The tolerance patterns, expressed as MICs, for 250 moderately halophilic eubacteria to 10 heavy metals were surveyed by using an agar dilution method. The moderate halophiles tested included 12 culture collection strains and fresh isolates representative of Deleya halophila (37 strains), Acinetobacter sp. (24 strains), Flavobacterium sp. (28 strains), and 149 moderately halophilic gram-positive cocci included in the genera Marinococcus, Sporosarcina, Micrococcus, and Staphylococcus. On the basis of the MICs, the collection strains showed, overall, similar responses to silver, cobalt, mercury, nickel, lead, and zinc. All were sensitive to silver, mercury, and zinc and tolerant of lead. The response to arsenate, cadmium, chromium, and copper was very heterogeneous. The metal susceptibility levels of the 238 freshly isolated strains were, in general, very heterogeneous among the four taxonomic groups as well as within the strains included in each group. The highest toxicities were found with mercury, silver, and zinc, while arsenate showed the lowest activity. All these strains were tolerant of nickel, lead, and chromium and sensitive to silver and mercury. Acinetobacter sp. strains were the most heavy-metal tolerant, with the majority of them showing tolerance of eight different metal ions. In contrast, Flavobacterium sp. strains were the most metal sensitive. The influence of salinity and yeast extract concentrations of the culture medium on the toxicity of the heavy metals tested for some representative strains was also studied. Lowering the salinity, in general, led to enhanced sensitivity to cadmium and, in some cases, to cobalt and copper. However, increasing the salinity resulted in only a slight decrease in the cadmium, copper, and nickel toxicities.(ABSTRACT TRUNCATED AT 250 WORDS)

Accumulation of Poly (beta-Hydroxybutyrate) by Halobacteria.

Some species of extremely halophilic archaebacteria, Halobacteriaceae, have been shown to accumulate large amounts of poly (beta-hydroxybutyrate) under conditions of nitrogen limitation and abundant carbon source. The production of poly (beta-hydroxybutyrate), at least in large quantities, was restricted to two carbohydrate-utilizing species, Halobacterium mediterranei and H. volcanii. In addition to the nutrients in the media, the salt concentration also influenced poly (beta-hydroxybutyrate) accumulation, which was greater at lower salt concentrations. The possible application of these microorganisms for the production of biodegradable plastics is discussed.