RESUMEN
Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.
RESUMEN
Original waveforms and optimized signal processing are proposed for frequency-modulated continuous-wave lidar for range finding, velocimetry, and laser anemometry. For range finding, the aim of this signal processing is to extend lidar range and reduce ambiguities. Moreover, the effect of moderate atmospheric turbulence on lidar efficiency is analyzed for infinite and finite targets, taking into account wind-induced bistatism. For laser anemometry, the aim is to measure air speed at the shortest distance farther than the rotor-induced turbulent volume around the helicopter and to avoid parasitic echoes coming from clouds or hard targets in the vicinity of a helicopter.
RESUMEN
Frequency-modulated continuous-wave lidar is evaluated for range finding, velocimetry, and laser anemometry. An original signal processing and waveform calibration for range finding leads to a reduction of computational effort while preserving capability for long-range measurement. Multiple target distance measurement is also demonstrated. For laser anemometry, the aim is to avoid parasitic echoes in the vicinity of a helicopter and to measure the air speed at the shortest distance farther than the rotor-induced turbulent volume around the helicopter. Flight tests of this functionality and vortex ring state warning are demonstrated.
RESUMEN
Renewed interest in heat stress effects on livestock productivity derives from climate change, which is expected to increase temperatures and the frequency of extreme weather events. This study aimed at evaluating the effect of temperature and humidity on milk production in highly selected dairy cattle populations across 3 European regions differing in climate and production systems to detect differences and similarities that can be used to optimize heat stress (HS) effect modeling. Milk, fat, and protein test day data from official milk recording for 1999 to 2010 in 4 Holstein populations located in the Walloon Region of Belgium (BEL), Luxembourg (LUX), Slovenia (SLO), and southern Spain (SPA) were merged with temperature and humidity data provided by the state meteorological agencies. After merging, the number of test day records/cows per trait ranged from 686,726/49,655 in SLO to 1,982,047/136,746 in BEL. Values for the daily average and maximum temperature-humidity index (THIavg and THImax) ranges for THIavg/THImax were largest in SLO (22-74/28-84) and shortest in SPA (39-76/46-83). Change point techniques were used to determine comfort thresholds, which differed across traits and climatic regions. Milk yield showed an inverted U-shaped pattern of response across the THI scale with a HS threshold around 73 THImax units. For fat and protein, thresholds were lower than for milk yield and were shifted around 6 THI units toward larger values in SPA compared with the other countries. Fat showed lower HS thresholds than protein traits in all countries. The traditional broken line model was compared with quadratic and cubic fits of the pattern of response in production to increasing heat loads. A cubic polynomial model allowing for individual variation in patterns of response and THIavg as heat load measure showed the best statistical features. Higher/lower producing animals showed less/more persistent production (quantity and quality) across the THI scale. The estimated correlations between comfort and THIavg values of 70 (which represents the upper end of the THIavg scale in BEL-LUX) were lower for BEL-LUX (0.70-0.80) than for SPA (0.83-0.85). Overall, animals producing in the more temperate climates and semi-extensive grazing systems of BEL and LUX showed HS at lower heat loads and more re-ranking across the THI scale than animals producing in the warmer climate and intensive indoor system of SPA.
Asunto(s)
Calor , Lactancia , Animales , Bovinos , Cambio Climático , Femenino , Trastornos de Estrés por Calor/veterinaria , Humedad , Leche/metabolismoRESUMEN
We prospectively assessed stool samples from 370 patients for Campylobacter species by comparing three selective agar media incubated at two temperatures: 42°C and 37°C. Twenty patients (5.4%) were found positive. The chromogenic medium CASA (AES Chemunex, France) proved highly efficient for C. jejuni and C. coli recovery, while lessening the workload in the lab.
Asunto(s)
Técnicas Bacteriológicas/métodos , Infecciones por Campylobacter/diagnóstico , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/aislamiento & purificación , Medios de Cultivo/química , Agar , Infecciones por Campylobacter/microbiología , Heces/microbiología , Francia , Humanos , Estudios Prospectivos , Selección Genética , TemperaturaRESUMEN
BACKGROUND AND OBJECTIVES: Porphyromonas gingivalis is frequently identified to type by evaluation of fimA polymorphisms and less often by pulsed-field gel electrophoresis (PFGE) because of the technical intricacies of PFGE. To compare these techniques, we genotyped P. gingivalis clinical isolates as to (i) their fimA type and (ii) their whole genome restriction profile (PFGE analysis). MATERIAL AND METHODS: Thirty-two P. gingivalis strains were isolated from 16 unrelated periodontitis patients. Two strains were isolated from each patient. Strains were subjected to a fimA-typing polymerase chain reaction (PCR) assay. Strains that could not be typed by PCR were submitted to sequencing of the entire fimA gene. The PFGE profiles of clinical strains were compared using bioinformatic analysis. RESULTS: Seven of the 32 isolates were not typeable by PCR and so their entire fimA gene was sequenced. The sequencing identified each strain as belonging to a single fimA type. In one case, sequencing of the fimA gene did not agree with the result obtained using fimA PCR typing. With the exception of one patient, each patient presented isolates bearing the same fimA type. However, in three patients, isolates with the same fimA type presented different PFGE pulsotypes. CONCLUSION: The P. gingivalis typing using fimA PCR has limitations in typeability and discriminatory power. A typing technique for P. gingivalis that is easy to perform but that presents adequate typeability and discriminatory power is needed if we want to better understand the epidemiology of periodontal disease.
Asunto(s)
Infecciones por Bacteroidaceae/microbiología , Proteínas Fimbrias/clasificación , Periodontitis/microbiología , Pili Sexual/clasificación , Porphyromonas gingivalis/clasificación , Técnicas de Tipificación Bacteriana , Células Clonales/clasificación , Electroforesis en Gel de Campo Pulsado , Proteínas Fimbrias/genética , Genoma Bacteriano/genética , Genotipo , Humanos , Filogenia , Pili Sexual/genética , Porphyromonas gingivalis/aislamiento & purificaciónRESUMEN
Various studies have demonstrated variations in the levels of virulence of different L. monocytogenes strains. In our laboratory, a plaque-forming assay followed by subcutaneous footpad inoculation of mice enabled us to estimate the prevalence of the low-virulence strains. This value fell from 16.3% to 1.7% with bacteria collected before 1994 and after 1997 respectively. This could be related to the modification in 1997 of the reference method EN ISO 11 290-1 of Listeria detection which recommended the use of polymyxin-acriflavine-LiCl-ceftazidime-aesculin-mannitol (PALCAM) medium. The aim of this study was to determine whether the percentage of low-virulence strains detected has changed due to the modification of the detection method recommending the use of the ALOA medium. After analyzing 380 L. monocytogenes strains, no increase in the percentage of low-virulence strains could be detected. The prevalence reached only 2.6% (ten of the 380 strains tested). The low virulence of L. monocytogenes strains was not related to rare serotypes and was also observed in serotypes usually involved in human disease. Low-virulence strains were found in dairy, meat, ready-to-eat products and also in the environment, highlighting the absence of one specific source. These results are discussed in terms of detection methods and the definition of low virulence.
Asunto(s)
Microbiología Ambiental , Microbiología de Alimentos , Listeria monocytogenes/aislamiento & purificación , Listeria monocytogenes/patogenicidad , Animales , Bovinos , Línea Celular Tumoral , Productos Lácteos/microbiología , Humanos , Listeria monocytogenes/clasificación , Carne/microbiología , VirulenciaAsunto(s)
Antibacterianos/administración & dosificación , Profilaxis Antibiótica , Artroplastia/métodos , Cementos para Huesos , Gentamicinas/administración & dosificación , Polimetil Metacrilato/administración & dosificación , Tobramicina/administración & dosificación , Antibacterianos/efectos adversos , Cementos para Huesos/efectos adversos , Cementos para Huesos/uso terapéutico , Gentamicinas/efectos adversos , Humanos , Polimetil Metacrilato/efectos adversos , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Insuficiencia Renal/complicaciones , Factores de Riesgo , Tobramicina/efectos adversosRESUMEN
This study is the first reported ion mobility detection of ethyl centralite and diphenylamine (DPA) smokeless gunpowder stabilizers, together with the nitroso and nitro derivatives of diphenylamine. First, the applicability of the ion mobility spectrometry (IMS) for the substances of interest was determined. The existence of numerous peaks, both in positive and negative modes, clearly demonstrates the success of these experiments. All mono and di-nitro derivatives of DPA tested were detected with this method. Unfortunately, many of the ions generated were not accurately identified. However, reduced mobility constants representative of each ion generated under defined operating conditions could be used for purpose of compound identification. The method was then successfully tested on real gunpowder samples. By the use of IMS, we managed to establish a rapid, simple and sensitive screening method for the detection and identification of smokeless gunpowder organic components.
RESUMEN
In August 2004, a case of rabies was diagnosed in a puppy that had been illegally imported from Morocco to Bordeaux (France). Because a great number of people and animals were thought to have come into contact with the puppy, extensive tracing measures were implemented, and an international alert was launched to trace and treat the contacts at risk. One hundred and eighty seven people received post-exposure treatment, eight of whom also received serovaccination, and 57 animals known to have been exposed to the puppy were tested. Six months after the death of the rabid animal, none of the people treated showed any signs of rabies, nor was any secondary animal case reported. The management of this crisis highlights the importance of the role of a rapid alert system at European level. Strict application of sanitary control regulations is essential for animals introduced into EU countries, and all necessary information must be made available to EU residents travelling to rabies enzootic areas.
Asunto(s)
Comercio/legislación & jurisprudencia , Control de Enfermedades Transmisibles , Trazado de Contacto , Enfermedades de los Perros/transmisión , Rabia/veterinaria , Zoonosis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Perros , Femenino , Francia , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Lactante , Internacionalidad , Masculino , Persona de Mediana Edad , Rabia/prevención & control , VacunaciónRESUMEN
At this time, many antibiotics have decreased activity against Streptococcus pneumoniae, a major agent of infectious disease. In this study, we evaluated antibiotic susceptibility and serogroups of strains isolated from bacteraemia, meningitis and acute otitis media in adults and children over the 1997-2003 period in Brittany, France. In 2003, 62% of the isolates were not susceptible to penicillin and 11% were fully resistant. The prevalence of erythromycin resistance was 63%. Resistance rates were higher among isolates recovered from children than adults. Serogroups 19 and 14 were the most frequently isolated, especially the 19 one among children. The emergence of this serogroup might be a consequence of the use of heptavalent conjugate vaccine introduced in 2001 in France. Future surveillance after vaccination will be needed to detect emerging serogroups and resistance among S. pneumoniae.
Asunto(s)
Streptococcus pneumoniae/efectos de los fármacos , Adulto , Niño , Farmacorresistencia Bacteriana , Francia , Hospitales Universitarios , Humanos , Penicilina G/farmacología , Serotipificación , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus pneumoniae/clasificaciónRESUMEN
In August 2004, a case of rabies was diagnosed in a puppy that had been illegally imported from Morocco to Bordeaux (France). Because a great number of people and animals were thought to have come into contact with the puppy, extensive tracing measures were implemented, and an international alert was launched to trace and treat the contacts at risk. One hundred and eighty seven people received post-exposure treatment, eight of whom also received serovaccination, and 57 animals known to have been exposed to the puppy were tested. Six months after the death of the rabid animal, none of the people treated showed any signs of rabies, nor was any secondary animal case reported. The management of this crisis highlights the importance of the role of a rapid alert system at European level. Strict application of sanitary control regulations is essential for animals introduced into EU countries, and all necessary information must be made available to EU residents travelling to rabies enzootic areas.
RESUMEN
Throughout 1999, clinical microbiology laboratories of 13 hospitals in Brittany have recovered Streptococcus pneumoniae isolates in 832 patients, 312 (37.5%) female and 518 (62.2%) male. Two hundred fifty five of them (30.6%) were children. One hundred eighty eight isolates were recovered from blood cultures (22.6%), 16 from CSF (1.9%), 449 from lungs (54%), and 88 from ear exsudates (10.6%).A 5 microgram oxacillin-disk test was used to detect isolates with reduced susceptibility to penicillin G. Determination of MICs of penicillin G, amoxicillin and cefotaxime were then performed by agar dilution method on 402 strains previously categorized resistant or intermediate. Five hundred forty six isolates were PSDP, 33.5% of them were resistant to penicillin G, 2.2% to amoxicillin and 0.2% to cefotaxime. As expected, a decreased susceptibility to beta-lactamins was frequently associated with resistance to macrolides, cotrimoxazole and tetracycline. Among PSDP, the most prevalent serotypes were 23 (23.7%), 14 (23.5%) and 19 (19.1%). In Brittany, the constant rise of PSDP (1993-1994: 28.5%; 1997: 56.4%; 1999: 65.6 %) could be perhaps explain by analysis of social and demographic data.
Asunto(s)
Farmacorresistencia Microbiana/fisiología , Infecciones Neumocócicas/epidemiología , Streptococcus pneumoniae/efectos de los fármacos , Adulto , Niño , Femenino , Francia/epidemiología , Humanos , Masculino , Penicilina G/uso terapéutico , Infecciones Neumocócicas/tratamiento farmacológico , Sistema de Registros , Serotipificación , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/aislamiento & purificaciónRESUMEN
Myoclonic-astatic epilepsy in early childhood: review of topical knowledge of clinical signs, electroencephalographic characteristics, etiology and therapy. The classification of epilepsy in childhood is discussed continuously. On the basis of some selected cases, the clinical and electrophysiological characteristics of myoclonic-astatic epilepsy in early childhood are described. On the one side we describe similarities of this entity and on the contrary side variabilities of the individual cases. New molecular results are described as possible reasons of the individual course of this disease. The topical options regarding therapy are prescribed.
Asunto(s)
Electroencefalografía , Epilepsias Mioclónicas/diagnóstico , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/efectos adversos , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/fisiopatología , Niño , Preescolar , Mapeo Cromosómico , Quimioterapia Combinada , Electroencefalografía/efectos de los fármacos , Epilepsias Mioclónicas/tratamiento farmacológico , Epilepsias Mioclónicas/genética , Epilepsias Mioclónicas/fisiopatología , Femenino , Lóbulo Frontal/efectos de los fármacos , Lóbulo Frontal/fisiopatología , Humanos , Hidrolasas/genética , Lactante , Masculino , Mutación/genética , Canal de Sodio Activado por Voltaje NAV1.1 , Canal de Sodio Activado por Voltaje NAV1.2 , Proteínas del Tejido Nervioso/genética , Canales de Sodio/genéticaRESUMEN
The synthesis of investigations of three salmonellosis outbreaks which occured in France between 1998 and 2000 confirms the role of the consumption of minced beef and highlights the importance of prevention measures.
Asunto(s)
Brotes de Enfermedades , Carne/microbiología , Intoxicación Alimentaria por Salmonella/epidemiología , Adolescente , Animales , Bovinos , Niño , Preescolar , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Intervalos de Confianza , Estudios Cruzados , Manipulación de Alimentos , Francia/epidemiología , Calor , Humanos , Lactante , Salmonella/clasificación , Intoxicación Alimentaria por Salmonella/microbiologíaRESUMEN
BACKGROUND: Total serum homocysteine (tHcy) has been used as an indicator of intracellular vitamin B-12, vitamin B-6, and folate status in adults, but data for neonates and infants are lacking. Vitamin B-12 deficiency may have fatal effects on neurologic development in infants; therefore, early diagnosis is crucial. OBJECTIVE: Our aim was to provide a reference range for tHcy in neonates and to explore the relation of tHcy to 1) serum vitamin concentrations, 2) the product of the transsulfuration pathway (cysteine), and 3) nutritional factors. DESIGN: tHcy, cysteine, folate, vitamin B-12, and vitamin B-6 were measured in 123 healthy, breast-fed neonates. The influence of nutrition (formula or human milk) on these variables was investigated in 60 infants. RESULTS: The mean (+/-SD) tHcy concentration was 7.8 +/- 3.1 micromol/L. tHcy showed a linear association with log vitamin B-12 (r = -0.64, P: < 0. 001), red blood cell folate (r = -0.33, P: < 0.001), and cysteine (r = 0.36, P: < 0.001). The strongest linear association was found between tHcy and the ratio of log cysteine to log vitamin B-12 (r = 0.71, P: < 0.0001). We found more neonates with probable tissue deficiencies of vitamin B-12 and folate on the basis of tHcy measurements than was expected from the analysis of serum vitamin concentrations alone (15.4% compared with 9.7%). Breast-fed infants had significantly lower vitamin B-12 concentrations and significantly higher serum tHcy and cysteine concentrations and ratios of log cysteine to log vitamin B-12 than did formula-fed infants (P: < 0.001). CONCLUSIONS: tHcy can be used as a functional indicator of vitamin B-12 and folate status in neonates. The ratio of cysteine to vitamin B-12 can be used as an additional index of impaired intracellular Hcy metabolism. tHcy and cysteine concentrations in infants are affected by nutritional factors.
Asunto(s)
Aminoácidos/metabolismo , Ácido Fólico/sangre , Piridoxina/sangre , Azufre/metabolismo , Vitamina B 12/sangre , Lactancia Materna , Estudios Transversales , Cisteína/sangre , Eritrocitos/metabolismo , Femenino , Homocisteína/sangre , Humanos , Alimentos Infantiles , Recién Nacido , MasculinoRESUMEN
Listeria monocytogenes Scott A grown in the minimal chemically defined medium M6LT was challenged to a concentration of either 35 or 65 g l(-1) of NaCl for 1 h in the presence of a [35S]cysteine-[35S]methionine labelling mix. The protein patterns were analysed by 2D-electrophoresis in the two conditions and isoosmotic condition (5 g l(-1) of NaCl in M6LT). A great number of proteins which were synthesized under isoosmotic conditions were either completely repressed or expressed at a reduced level, at 65 g l(-1) and to a lesser extent at 35 g l(-1) of NaCl. At 35 g l(-1) of NaCl, six proteins were up-regulated, five proteins showed no change in expression level and five were repressed. Among the proteins up-regulated at 35 g l(-1) of NaCl, a single one (18.7 kDa, pI 5.05) was up-regulated at 65 g l(-1) too. We observed 21 proteins which were repressed at 65 g l(-1) of NaCl, among which 11 completely disappeared. Some of the up-regulated proteins have characteristics of molecular weight and isoelectric point close to those of stress proteins reported elsewhere: the protein induced both at 35 and 65 g l(-1) might correspond to a previously proposed universal stress protein of Listeria. Some proteins which were repressed at 65 g l(-1) have molecular weights close to those of virulence proteins.
Asunto(s)
Proteínas Bacterianas/biosíntesis , Listeria monocytogenes/metabolismo , Cloruro de Sodio/farmacologíaRESUMEN
Erysipleas, also known as Saint Anthony's fire, is an acute infection of the skin caused, in most of cases, by group A streptococci. In the past, the most common site of involvement was the face and, in the pre-antibiotic era, mortality was high. In this retrospective study, we highlight the clinical and bacteriological features and report follow-up in 92 patients hospitalized in an internal medicine unit between 1st March 1992 and 31st December 1996 for 94 episodes of erysipelas. The involvement of the lower limbs predominated as involvement of the face is becoming very rare. Streptococci from others groups and Staphylococcus aureus have been implicated on occasions. Recovery is usual even if this infection may greatly weaken these often fragilized patients. In this paper, antibiotic treatment as well as the place of anticoagulants and Doppler ultrasound are discussed. Hospitalization is often necessary but it must not be systematic.
Asunto(s)
Erisipela/fisiopatología , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Anticoagulantes/uso terapéutico , Erisipela/diagnóstico por imagen , Erisipela/tratamiento farmacológico , Erisipela/microbiología , Dermatosis Facial/microbiología , Dermatosis Facial/fisiopatología , Femenino , Estudios de Seguimiento , Hospitalización , Humanos , Pierna/irrigación sanguínea , Dermatosis de la Pierna/diagnóstico por imagen , Dermatosis de la Pierna/microbiología , Dermatosis de la Pierna/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Cutáneas Estafilocócicas/fisiopatología , Streptococcus/clasificación , Streptococcus pyogenes/fisiología , Ultrasonografía Doppler , Trombosis de la Vena/diagnóstico por imagenRESUMEN
The existence of a viable but nonculturable (VBNC) state has been described for Campylobacter jejuni as it had been for a number pathogenic bacteria. Three C. jejuni human isolates were suspended in surface water and subsequently entered the VBNC state. After starvation for 30 days, VBNC cells were inoculated in the yolk sacs of embryonated eggs. Culturable cells were detected in a large proportion of the embryonated eggs inoculated with VBNC C. jejuni cells. Recovered cells kept their adhesion properties.
Asunto(s)
Adhesión Bacteriana , Campylobacter jejuni/fisiología , Animales , Técnicas Bacteriológicas , Campylobacter jejuni/crecimiento & desarrollo , Campylobacter jejuni/aislamiento & purificación , Embrión de Pollo , Escherichia coli/fisiología , Células HeLa , Humanos , Listeria monocytogenes/fisiología , Factores de Tiempo , Saco Vitelino/microbiologíaRESUMEN
We combined the use of low inoculation titers (300 +/- 100 CFU/ml) and enumeration of culturable cells to measure the osmoprotective potentialities of dimethylsulfoniopropionate (DMSP), dimethylsulfonioacetate (DMSA), and glycine betaine (GB) for salt-stressed cultures of Escherichia coli. Dilute bacterial cultures were grown with osmoprotectant concentrations that encompassed the nanomolar levels of GB and DMSP found in nature and the millimolar levels of osmoprotectants used in standard laboratory osmoprotection bioassays. Nanomolar concentrations of DMSA, DMSP, and GB were sufficient to enhance the salinity tolerance of E. coli cells expressing only the ProU high-affinity general osmoporter. In contrast, nanomolar levels of osmoprotectants were ineffective with a mutant strain (GM50) that expressed only the low-affinity ProP osmoporter. Transport studies showed that DMSA and DMSP, like GB, were taken up via both ProU and ProP. Moreover, ProU displayed higher affinities for the three osmoprotectants than ProP displayed, and ProP, like ProU, displayed much higher affinities for GB and DMSA than for DMSP. Interestingly, ProP did not operate at substrate concentrations of 200 nM or less, whereas ProU operated at concentrations ranging from 1 nM to millimolar levels. Consequently, proU(+) strains of E. coli, but not the proP(+) strain GM50, could also scavenge nanomolar levels of GB, DMSA, and DMSP from oligotrophic seawater. The physiological and ecological implications of these observations are discussed.