Functional phenotypic plasticity mediated by water stress and [CO2] explains differences in drought tolerance of two phylogenetically close conifers.

Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, may also differ between species. We analysed functional plasticity in seedlings of two taxonomically close pine species (Pinus pinaster Ait., Pinus pinea L.) under different [CO2] and water stress levels. The multidimensional functional trait variability was more influenced by water stress (preferentially xylem traits) and [CO2] (mostly leaf traits) than by differences between species. However, we observed differences between species in the strategies followed to coordinate their hydraulic and structural traits under stress. Leaf 13C discrimination decreased with water stress and increased under elevated [CO2]. Under water stress both species increased their sapwood area to leaf area ratios, tracheid density and xylem cavitation, whereas they reduced tracheid lumen area and xylem conductivity. Pinus pinea was more anisohydric than P. pinaster. Pinus pinaster produced larger conduits under well-watered conditions than P. pinea. Pinus pinea was more tolerant to water stress and more resistant to xylem cavitation under low water potentials. The higher xylem plasticity in P. pinea, particularly in tracheid lumen area, expressed a higher capacity of acclimation to water stress than P. pinaster. In contrast, P. pinaster coped with water stress comparatively more by increasing plasticity of leaf hydraulic traits. Despite the small differences observed in the functional response to water stress and drought tolerance between species, these interspecific differences agreed with ongoing substitution of P. pinaster by P. pinea in forests where both species co-occur. Increased [CO2] had little effect on the species-specific relative performance. Thus, a competitive advantage under moderate water stress of P. pinea compared with P. pinaster is expected to continue in the future.

A validated GC-MS method for ketamine and norketamine in hair and its use in authentic cases.

This work has shown that it is a valid method for determining ketamine, norketamine and amphetamines derivates in hair samples of forensic cases. This method was validated meeting the criteria of sensitivity and accuracy for detecting repeated consumption of ketamine in hair samples of forensic interest, according to the proposed cut-off for ketamine of 0.5 ng/mg. The detection of norketamine allowed discriminating between active uses and external contamination. The assessed method was applied for analyzing 1189 hair samples of judicial interest received in the INTCF along 15 months, obtaining 62 positive in ketamine consumption. This means a 5.2% of positivity. Ketamine consumers present a profile of young age (21-30 years old), polydrug use with consumption of synthetic substances preferably MDMA and, then, amphetamine. As consumer is collective, prone to consume new psychoactive substances, requires special attention due to they show a consumer profile with higher prevalence in MDMA than amphetamine, indicating that ketamine consumers belong to a subgroup with a different profile within the INTCF casuistry. The results of the exercises of the proficiency tests performed satisfactorily in all cases. In conclusion, it is a suitable method also to evaluate the chronic consumption of ketamine, in addition to amphetamines in the same method of analysis.

Characterization of Shiga Toxin-Producing Escherichia coli O157 Isolates from Bovine Carcasses.

The main purpose of this study was to determine the prevalence of Escherichia coli O157 on bovine carcasses before and after chilling at a large slaughterhouse located in the city of Barcelona, Spain, to assess the effectiveness of dry chilling on reducing E. coli O157 contamination of carcasses. In addition, the study characterized the E. coli O157 strains isolated in terms of virulence factors, antibiotic susceptibility, and their genetic diversity. Individual bovine carcasses were sampled before (n = 300) and after (n = 300) chilling over an 8-month period. Positive samples for E. coli O157 were subjected to virulence screening by PCR (stx1, stx2, and eaeA genes and the fliCH7 gene), antimicrobial susceptibility testing, and molecular typing by pulsed-field gel electrophoresis. A total of 9.7% (29 of 300) of the nonrefrigerated carcasses examined and 2.3% (7 of 300) of the refrigerated carcasses were positive for E. coli O157. All the isolates were serotype O157:H7, 92% (33 of 36) carried the stx1, stx2, and eaeA genes, and 8% (3 of 36) carried the stx2 and eaeA genes. Antimicrobial susceptibility testing showed a high degree of resistance: 29 strains (81%) were resistant to at least 1 antimicrobial of the 12 antimicrobials tested; 69% (25 of 36) were resistant to 4 or more antimicrobials. Molecular typing by pulsed-field gel electrophoresis found a high diversity of genetic types, implying little cross-contamination in the slaughterhouse. This study confirms that E. coli O157:H7 is present on the carcasses slaughtered in Spain, although its prevalence is reduced by the dry chilling process used. The recovered isolates showed potential pathogenesis and a high degree of multidrug resistance, confirming the importance of bovine meat monitoring.

High incidence of norovirus GII.4 outbreaks in hospitals and nursing homes in Catalonia (Spain), 2010-2011.

A descriptive study was performed between 1 January 2010 and 31 December 2011 to estimate the incidence of norovirus outbreaks in hospitals and nursing homes in Catalonia (Spain). Epidemiological surveys were done for each outbreak. Norovirus was confirmed using RT-PCR. The incidence of outbreaks/106 person-years by centre, and the attack rate, were calculated. Statistically significant differences were calculated using odds ratio (ORs) and 95% confidence intervals (CIs). Person-to-person transmission was responsible for 81·5% (22/27) of outbreaks. The incidence in the population was 156·7 outbreaks/106 person-years. The incidence by centre was 1·3% per year and was greater in hospitals (2·6%) than in nursing homes (0·9%) (OR 3·2, 95% CI 1·5-6·9). The global attack rate in residents and staff was 34·7% (816/2348). The mortality rate was 0·25% (2/816). Genogroup GII.4 caused 66·7% of outbreaks. Norovirus GII.4 outbreaks cause significant morbidity affecting both patients and staff.

Cases of acute gastroenteritis due to calicivirus in outbreaks: clinical differences by age and aetiological agent.

The Caliciviridae family includes norovirus and sapovirus, which both cause acute gastroenteritis (AGE). Currently, norovirus is the most common cause of AGE in all age groups in many countries. We analysed clinical differences in reported cases of acute gastroenteritis caused by caliciviruses (AGC) by age group and agent involved. We conducted a descriptive study of AGE outbreaks reported to the Public Health Agency of Catalonia (Spain) in 2010 and 2011. The odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to estimate the association between clinical symptoms and age. Clinical differences between the <15 years and ≥15 years age groups were statistically significant: children more frequently presented with vomiting (OR, 3.25; 95% CI, 2.56-4.13), abdominal pain (OR, 3.27; 95% CI, 2.60-4.12), fever (OR, 1.51; 95% CI, 1.17-1.96) and nausea (OR, 1.49; 95% CI, 1.19-1.85). Comparing clinical manifestations of sapovirus and norovirus infection in children aged <15 years, cases caused by norovirus more frequently presented with vomiting and fever (p <0.001), and cases caused by sapovirus more frequently presented with diarrhoea (p 0.013). Determination of the clinical differences associated with cases in outbreaks according to the age of the majority of cases and the symptoms most frequently detected may aid decision making and guide aetiological investigations and the adoption of prevention and control measures.

Norovirus: a growing cause of gastroenteritis in catalonia (Spain)?

Infectious acute gastroenteritis (AGE) is a major health problem worldwide. Salmonella is a leading cause of AGE outbreaks, but viruses may be responsible for up to 80% of cases. We compared the frequency and characteristics of AGE out breaks in Catalonia due to norovirus and Salmonella and the changes in these outbreaks from 2000 through 2010. In 2006 through 2010, we also investigated the distribution by season, setting, and implicated food, the incidence rates of cases associated, and the hospitalization rates. Differences in proportions were estimated by Pearson's chi-square test, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. In 2000 through 2010, the number of AGE outbreaks caused by Salmonella decreased and those caused by norovirus significantly increased. From 2006 onward, norovirus was the most common etiology in AGE outbreaks, but in foodborne outbreaks, Salmonella was the more common cause until 2010. The incidence rate per 10(5) inhabitants was greater for norovirus (20.81 versus 3.97, P < 0.001), and the hospitalization rate was lower for norovirus (0.84 versus 4.69, P < 0.001). Salmonella infections occurred more frequently in the warmer months, and norovirus infections were more common in the colder months, both in terms of total outbreaks (OR = 4.50; 95% CI, 2.85 to 7.11; P < 0.001) and foodborne outbreaks (OR = 4.38; 95% CI, 2.42 to 7.95; P < 0.001). Norovirus infections were less common in private homes (OR = 0.08; 95% CI, 0.04 to 0.14; P < 0.001) and more common in nursing homes (P < 0.001) and hospitals or long-term care facilities (OR = 14.09; 95% CI, 3.35 to 59.33; P < 0.001). Foods most frequently implicated in norovirus infection outbreaks were seafood (22% ; OR = 7.89; 95% CI, 2.59 to 24.3; P < 0.001), and those most common in Salmonella infection outbreaks were mayonnaise and similar items (30.2%; OR = 0.05; 95% CI, 0.01 to 0.22; P < 0.001). Foodborne outbreaks in which the vehicle was not identified were more frequent in cases of norovirus infection (OR = 4.59; 95% CI, 2.54 to 8.30; P < 0.001). Our results indicate that norovirus rather than Salmonella is the most common cause of AGE outbreaks in Catalonia. Foodborne AGE outbreaks were more commonly caused by norovirus than by Salmonella only in 2010, the last year of the study.

Epidemiological and clinical features of norovirus gastroenteritis in outbreaks: a population-based study.

Noroviruses are the most frequent cause of acute gastroenteritis in the community. In Catalonia, it is not clear how this type of viral gastroenteritis is evolving, and the objective of this prospective population-based study was to describe the incidence and epidemiological and clinical features of outbreaks of acute gastroenteritis due to norovirus in Catalonia between October 2004 and October 2005. Incidence rates were calculated using the estimated population of Catalonia in 2005. For each outbreak, the mode of transmission, the number of persons affected, demographic variables, clinical presentation, the date and time of onset of symptoms and the duration of symptoms, physician visits and hospitalizations were collected. Sixty viral outbreaks affecting 1791 people were identified, with no distinct seasonality. The mean number of outbreaks per month was 4.6. The global incidence was 24.6 per 100 000 person-years. The incidence was higher in women (25.7 per 100 000 person-years) and in the 5-11 years (52.4 per 100 000 person-years) and > or =65 years (42.4 per 100 000 person-years) age groups. The prevalence of vomiting, abdominal pain and general malaise was higher in children and adolescents, whereas the prevalence of diarrhoea and myalgia was higher in adults. These results suggest that norovirus infection has an important public health impact in Catalonia and that prevention strategies should be designed and implemented.

In vitro activities of 22 antimicrobial agents against Listeria monocytogenes strains isolated in Barcelona, Spain. The Collaborative Study Group of Listeriosis of Barcelona.

The in vitro activity of 22 antimicrobial agents against 82 human Listeria monocytogenes strains isolated in Barcelona from 1994 to 1998 was determined. Ampicillin and gentamicin showed good in vitro activity against all strains (MIC90: 1 and < or = 0.25 microg/ml, respectively). No resistance to rifampin or co-trimoxazole was detected and only one strain was resistant to tetracycline. Of the nine fluoroquinolones tested, clinafloxacin and gemifloxacin were the most active compounds (MIC90: 0.12 and 0.25 microg/ml, respectively). No increasing MICs values were observed during the five-year period.

Oestrid myiasis in European mouflon from Spain.

From February 1992 to March 1997, 245 European mouflon (Ovis orientalis musimon) from Sierras de Cazorla, Segura y Las Villas Natural Park (southern Spain) were surveyed for oestrid larvae in order to estimate prevalence and mean intensity of parasitism by Oestrus ovis. Over 46 percent of the animals surveyed were infected, with a mean intensity of 9.6 larvae/host parasitized. No significant differences in prevalence rates between host sexes were observed, but older mouflons were infected with more larvae than younger ones.

Initial numbers, serovars and phagevars of Listeria monocytogenes isolated in prepared foods in the city of Barcelona (Spain).

A total of 1100 samples of prepared foods purchased in restaurants and delicatessen shops in the city of Barcelona was examined for the presence of Listerio. L. monocytogenes was more frequently isolated from foods intended to be consumed without further cooking (9.3%) than from foods intended to receive further cooking prior to consumption (2.9%). A quantitative study, carried out with 773 samples, yielded 1% of samples with numbers of L. monocytogenes higher than 100 CFU/g. Strains of L. monocytogenes belonged to serovar 4b (36.3%), 1/2a (29.5%), 1/2b (22.7%) and 1/2c (11.3%). L. monocytogenes serovar 4b phagevar 3274: 2671 (6 of 11) was prevalent among the strains studied.

Perinatal listeriosis: a population-based multicenter study in Barcelona, Spain (1990-1996).

The aim off this study was to describe the incidence, epidemiology, clinical presentation, and outcome of perinatal listeriosis for a 7-year period (1990-1996) based on data of an active population-based surveillance project implemented in the city of Barcelona, Spain. There were 30 cases (20.8%) associated with pregnancy (15 pregnant women, 13 neonates, and 2 fetal deaths). The incidence of perinatal listeriosis varied from 4.1 to 0 per 10,000 live births. The proportion of perinatal cases in relation to the total number of cases of listeriosis varied between 0 and 42%. Early-onset neonatal sepsis accounted for 12 of 13 live births. The mean age of infected pregnant women with listeriosis was 30.1+/-2.0 years. Chorioamnionitis was the predominant clinical form (86.7%). Only two mothers had primary bacteremia by L. monocytogenes in the second trimester of pregnancy. Both infants were born healthy, without signs of infection. One of these mothers was infected with the human immunodeficiency virus (HIV). Since January 1994, 12 strains were available for serotyping and phagotyping; 9 belonged to serovar 4b, 2 to serovar 1/2b, and 1 to serovar 1/2a. No outbreaks of L. monocytogenes infection occurred during the study period. The overall neonatal mortality rate was 7.7% among infected live births. All pregnant women were treated with ampicillin and none died. Early antenatal treatment with ampicillin improves neonatal outcome and can result in the birth of healthy babies.

Intestinal carriage of campylobacters, salmonellas, yersinias and listerias in pigeons in the city of Barcelona.

The faecal bacterial flora of pigeons, which may be the source of infectious diseases in man, was studied in the city of Barcelona. Four hundred cloacal specimens were examined for Campylobacter jejuni, Camp. coli, Salmonella spp., Yersinia spp. and Listeria spp., over a 12 month period. Campylobacter jejuni was the most frequently isolated micro-organism, found in 105 pigeons (26.2%), with a greater incidence in the districts of the city with a high density of pigeons and without seasonal variation. Salmonella spp. were isolated from six specimens (1.5%) and Yersinia intermedia was isolated from only one pigeon.

[Application of molecular epidemiology techniques in the study of food poisoning caused by Staphylococcus aureus]. / Aplicación de las técnicas de epidemiología molecular en el estudio de una toxiinfección alimentaria por Staphylococcus aureus.

BACKGROUND: The use of molecular epidemiology techniques has provided better knowledge as to the clonal organization of bacterian populations and thus allows better follow up of epidemics. An alimentary toxiinfection in a Barcelona school produced by Staphylococcus aureus was analyzed by the combination of epidemiologic, phenotype and genotype markers with the aim of determining the source of the alimentary contamination. METHODS: Nine strains of Staphylococcus aureus isolated in 6 food manipulators and 3 patients were studied with the following markers: biotype, antibiotype, phagotype, plasmid profile, polymorphism of the size of the restriction fragments of total DNA and ribotype. RESULTS: Epidemiologic study of the strains analyzed showed that both the phenotype markers and the plasmid profile are thecniques of little discriminatory value. The only clearly discriminatory technique used was ribotyping which defined 3 clones in the 9 strains of Staphylococcus aureus studied. CONCLUSIONS: Molecular study of isolated strains of Staphylococcus aureus was able to identify the causal origin of the alimentary toxiinfection in one of the 6 food manipulators studied.

Incidence of Listeria monocytogenes in fresh foods in Barcelona (Spain).

From September 1989 to March 1990, a study of Listeria spp. was carried out on 311 samples of raw foodstuffs from markets and other establishments in the city of Barcelona. These foodstuffs included vegetables (103 samples), minced meats from pork, beef and poultry (168 samples) and bivalve molluscs (40 samples). L. monocytogenes was isolated in 7.8% of the vegetable samples, 17.3% of the minced meats and in 7.5% of bivalve molluscs. The most frequent serovars were 1/2 and 4. Other species isolated were L. innocua, L. welschimeri and L. seeligeri.

Determination of Aflatoxins in Bread and Bakery Products.

The possible presence of aflatoxins B1, B2, G1 and G2 was studied on 50 samples of bread and 50 samples of bakery products. The methods used in sample analysis were the following: (a) aflatoxin determination by thin layer chromatography (TLC) with chloroform/acetone solvent system (88/12); and (b) by high pressure liquid chromatography, with the toluene/ethyl acetate/methanol solvent system (68/29/3). With both methods, separations obtained of the different aflatoxins were optimal for accurate identification. Presence of aflatoxins B1 and G1 was detected in the extract from a sample of the bakery products group, using both methods mentioned.