The epidemiology of invasive Streptococcus pneumoniae disease in Catalonia (Spain). A hospital-based study

The aim of this study was to investigate the incidence of invasive pneumococcal disease (IPD) in Catalonia. A hospital-based incidence study of the period 1997-1999 was carried out by reviewing the isolations of Streptococcus pneumoniae obtained from normally sterile sites reported by the hospitals that voluntarily participate in the Microbiological Reporting System of Catalonia (MRSC), and those obtained by active retrospective surveillance of cases recorded by microbiology laboratories of the remaining hospitals. Cases of pneumonia were included only if the blood culture was positive. The age, sex and clinical presentation of each patient were recorded. The global incidence of hospital-based IPD was 10.5 per 100,000 persons-year, and was much higher in subjects <2 years of age (59.6) and in those aged > or = 65 years (27.9). In subjects > or = 65 years, bacteremic pneumococcal pneumonias were more frequent in the months from December to March than they were in children <2 years of age (P<0.0001). The global incidence of IPD (10.5 per 100,000 persons-year) is high in Catalonia, greater than that of meningococcal or Haemophilus influenzae invasive disease. In children <2 years, the incidence is nearly six times higher (59.6 per 100,000 persons-year) with pneumonias (rate of 26.2 per 100,000 persons-year) and non-focal bacteremias (rate of 22.1 per 100,000 persons-year) being especially frequent.

Regeneration of transgenic citrus plants under non selective conditions results in high-frequency recovery of plants with silenced transgenes

Insertion of foreign DNA into plant genomes frequently results in the recovery of transgenic plants with silenced transgenes. To investigate to what extent regeneration under selective conditions limits the recovery of transgenic plants showing gene silencing in woody species, Mexican lime [ Citrus aurantifolia (Christm.) Swing.] plants were transformed with the p25 coat protein gene of Citrus tristeza virus (CTV) with or without selection for nptII and uidA. Strikingly, more than 30% of the transgenic limes regenerated under non-selective conditions had silenced transgenes, and in all cases silencing affected all the three transgenes incorporated. These results indicate that the frequency of transgene silencing may be greatly underestimated when the rate of silencing is estimated from the number of regenerants obtained under selective conditions. To our knowledge, this is the first report in which the frequency of gene silencing after transformation has been quantified. When the integration pattern of T-DNA was analyzed in silenced and non-silenced lines, it was observed that inverted repeats as well as direct repeats and even single integrations were able to trigger gene silencing. Gene silencing has often been associated with the insertion of DNA sequences as inverted repeats. Interestingly, here, direct repeats and single-copy insertions were found in both silenced and non-silenced lines, suggesting that the presence of inverted-repeat T-DNAs and the subsequent formation of dsRNAs triggering gene silencing cannot account for all silencing events.

Utilisation of lignocellulosic wastes for lignin peroxidase production by semi-solid-state cultures of Phanerochaete chrysosporium

In the present work, the production of ligninolytic enzymes by semi-solid-state cultures of Phanerochaete chrysosporium BKM-F-1767 (ATCC 24725), employing different lignocellulosic wastes as support, was investigated. The waste materials employed were grape seeds, wheat straw and wood shavings. Maximum lignin peroxidase activities of 1,620 +/- 123 U/l,364 +/- 35 U/l and 571 +/- 42 U/l were attained, respectively. Nevertheless, low manganese-dependent peroxidase activities were found, being insignificant in the grape seed cultures. Moreover, the in vivo decolourisation of a model dye compound, the polymeric dye Poly R-478 (polyvinylamine sulfonate anthrapyridone), by the above-mentioned cultures was monitored to assess the degrading capability of the extracellular liquid secreted by such cultures. The percentage of biological decolourisation attained by grape seed and wood shaving cultures was around 74% and 63%, respectively, whereas it was rather low (40%) in the wheat straw ones.

Tuberculosis in Spain: epidemiological pattern and clinical practice

SETTING

Thirteen Autonomous Regions in Spain.

OBJECTIVE

To study the incidence of all forms of tuberculosis (TB) and investigate clinical practice in TB.

DESIGN

Cases of all forms of tuberculosis diagnosed in the study setting from May 1986 to April 1997 were identified though active search of different databases. Clinical and epidemiological information on cases was collected from clinical records or by interview with physicians.

RESULTS

The overall incidence of all forms of tuberculosis was 38.5/100,000 and the incidence of smear-positive disease was 13.83/100,000. Most cases (97.1%) were Spanish nationals, with rates higher in men than in women (52.7/100,000 vs. 24.87/100,000) and in groups aged 25-34 and 75 years and over (61.35/100,000 and 59.35/100,000, respectively). Disseminated forms were frequent (6.6%), and the most common risk factor was human immunodeficiency virus (HIV) infection (17.7% of cases). Hospitalisation was common (71.6%). Microbiological confirmation of diagnosis was sought for 87.7% of the cases (91.8% of pulmonary vs. 75.5% of extra-pulmonary cases), and 65.2% were culture-positive (73.8% of pulmonary vs. 39.7% of extra-pulmonary cases). HIV-infected patients were treated in almost equal proportions with three or four drugs (49.7% and 48.2%, respectively), while HIV-negative cases or those whose HIV status was unknown were usually treated with three drugs.

CONCLUSION

The epidemiological pattern of TB in Spain is different to other industrialised countries in the age distribution of cases and the proportions of foreigners and cases with HIV infection. Microbiological confirmation of diagnosis is more common in pulmonary than in extra-pulmonary disease, and treatment with four drugs more frequent in HIV-positive cases.

The genome sequence of Schizosaccharomyces pombe

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.

Impact of highly active antiretroviral therapy on fever of unknown origin in HIV-infected patients

In order to assess the impact of highly active antiretroviral therapy (HAART) on the frequency and etiology of fever of unknown origin in HIV-infected patients, a retrospective study was performed on cases of fever of unknown origin observed from January 1997 to December 1999 in seven hospitals in five cities in Andalusia, Spain. During the period specified, a total of 4,858 HIV-infected patients receiving HAART and 2,787 HIV-infected individuals not receiving HAART were studied. The frequency of fever of unknown origin was 0.6% in patients receiving HAART and 3% in non-HAART patients (P=0.001). Human immunodeficiency virus infection was the only cause of fever found more frequently in the non-HAART patient group (P=0.07). The study findings suggest that the use of HAART has reduced the frequency of fever of unknown origin in HIV-infected patients, but the etiology of the condition remains mostly unchanged.

Community-based seroepidemiological survey of HCV infection in Catalonia, Spain

In a recent expert meeting, Swedish recommendations for the treatment of HCV infection were updated. An interferon-free combination of direct-acting antiviral agents was recommended as the first line standard-of-care treatment for chronic HCV infection. Interferon-based therapy should be considered as a second line option after an individual benefit-risk assessment. Treatment is strongly recommended for HCV infected patients with bridging fibrosis or cirrhosis (Metavir stages F3–4), before and after liver transplantation, and in the presence of extra-hepatic manifestations. Additionally, patients with moderate liver fibrosis (stage F2) as well as women in need of in vitro fertilisation should be prioritised for therapeutic intervention. Treatment indications for people who inject drugs, children, chronic kidney disease and HIV co-infection are also discussed.

Photocatalytic degradation of dyes in aqueous solution operating in a fluidised bed reactor

This work reports a preliminary design of a new photochemical reactor and its application to photochemical degradation of two dyes, Crystal Violet and Azure B, operating in both batch and continuous processes. A novel kind of photocatalyst, consisting of ZnO immobilised in alginate gel beads, which is able to photodegrade organic dyes effectively, has been employed in the present study. When this photocatalyst, at a concentration of 1 g of ZnO per litre of alginate gel at 3%, was employed in batch process, almost total decolourisation of Crystal Violet in reaction times lower than 120 min was observed. Operating in continuous process at different residence times, it was possible to achieve a total decolourisation of both Crystal Violet and Azure B. Moreover, the total organic carbon content (TOC) was reduced to 90% in the former and to 52% in the latter. These results indicated that the photoreactor developed in the present work was able to degrade effectively dyes of different structures, revealing the non-specificity of the system.

Prevalence of Neisseria meningitidis carriers in the school population of Catalonia, Spain

The aim of this study was to determine the prevalence of healthy Neisseria meningitidis pharyngeal carriers in a representative sample of the Catalonian school population, as well as its associated factors. The sample was divided into age groups: < or = 5, 6-7 and 13-14 years old. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. Oropharyngeal swabs were collected with a cotton-tipped swab in an Amies transport medium and cultured on Thayer Martin plates at 35 degrees C in 5% CO2. The isolates were serogrouped and sero/subtyped. Of the 1406 children studied, 75 (5.34%) meningococcal carriers were detected: 63 B (4.5%), 9 non groupable (0.7%), 2 29E (0.1%) and 1X (0.07%). No serogroup C meningococci were found in this study, probably due to the high A+C vaccination coverage of up to 68.9% in children 6-7 years old. Bivariate analysis identified six statistically significant risk factors for meningococcal carriage: increasing age, recent upper respiratory tract infection, previous antibiotic treatment, number of students in the class, size of the classroom and social class. Multivariate analysis found that only age and previous antibiotic treatment remained statistically significant when the other factors were controlled.

Community-based seroepidemiological survey of HCV infection in Catalonia, Spain

The objective of this study was to investigate the prevalence of antibodies against the hepatitis C virus (anti-HCV) and the associated risk factors in a representative sample of the population of Catalonia, Spain. Serum samples from 2,142 subjects aged between 5 and 70 years, selected at random from urban and rural habitats, were studied. Multiple logistic regression analysis was carried out to determine variables associated independently with the presence of HCV antibodies. The age and gender standardized prevalence of anti-HCV was 2.5% (95% confidence interval, 1.8-3.2). Prevalence increased significantly with age (P < 0.001), but no other sociodemographic variables were associated with HCV infection. Tattoos (OR: 6.2), blood transfusions (OR: 5.0) intravenous drug use (OR: 4.9) and antecedents of hospitalization (OR: 2.3) were variables associated independently with infection. HCV infection affects mainly elderly people in Spain and spares children and adolescents. This suggests that major exposure to HCV may have occurred many years ago, when infection was more widespread than in recent years.

Factors affecting the morphogenetic switch in Yarrowia lipolytica

Yarrowia lipolytica is a dimorphic yeast usually isolated from dairy products. Here we described methods for inducing in a homogeneous way a true yeast-hypha transition in liquid medium. As a first step, the cells must be synchronized in the G1 phase of the cell cycle by nitrogen starvation. Using either N-acetylglucosamine (GlcNAc) or serum as the only carbon sources, more than 90% of the cells form hypha after 4-6 h of incubation. Bovine albumin is also able to induce the yeast-hypha transition, although to a lesser extent. The addition of glucose to cultures growing with GlcNAc arrest the morphogenetic switch but not when added to cultures growing in the presence of serum. Serum also induces invasive growth in solid medium. Neither pH, nitrogen starvation, nor temperature play a relevant role in the morphogenetic switch. Our results suggest that, as occurs in Candida albicans, at least two morphogenetic signal pathways exist in Y. lipolytica.

Estimated varicella incidence on the basis of a seroprevalence survey

Varicella is a disease caused by varicella-zoster virus. It is transmitted via the respiratory route, is highly communicable and mainly affects young children. An effective vaccine is now available, whose routine use is advised by health authorities in the USA and which can prevent severe disease, although breakthrough infections do occur. In deciding whether or not to include a vaccine in the routine vaccination schedule, knowledge of the morbidity of the disease in question is fundamental. Although reporting of varicella is compulsory in Catalonia, doctors only have to report the weekly number of cases diagnosed, and not their age distribution. Given that recent data on the prevalence of the infection in Catalonia according to age groups is available, it was considered that, using these data, an estimation of age-related incidence could be made. The objective of the present study was to estimate the incidence of varicella in Catalonia on the basis of the available seroprevalence data. A curve was fitted to the observed prevalence and point prevalence estimates for all ages were obtained. The incidence was derived by smoothed prevalence for each of these age groups. Estimated variance of the estimated incidence was obtained by the delta method. Predicted prevalence in the 0-4 years age group was calculated by the smoothed prevalence. The model that best fitted the sample prevalence was the exponential function. The estimated number of varicella cases in this study was 46,419 (95% CI 40,507-52,270). As the population in Catalonia in 1996 was 6,090,040, the previous results give an incidence rate of 762.2 per 100,000 persons/year with their 95% CI (666.1-858.3). The method described may be applied to the study of incidence rates in relation to the prevalence of diseases if we accept that the infection produces permanent immunity; the risk of mortality is the same for infected and non-infected subjects and that the disease incidence and population remain constant in time.

The sequence of a 15 769 bp segment of Pichia anomala identifies the SEC61 and FBP1 genes and five new open reading frames

We have determined the sequence of a 15 769 bp DNA segment of Pichia anomala. The sequence contains seven complete open reading frames (ORFs) longer than 100 amino acids and a putative tRNA gene. Two of the ORFs code for the well-characterized genes SEC61 (which codes for the core subunit of the ER translocation complex) and FBP1 (encoding fructose-1,6-bisphosphatase). A gene coding for a protein similar to S. cerevisiae YDL054c was found between the two genes. These three genes show a different organization (intermingled triples) in three yeast species: Saccharomyces cerevisiae, Candida albicans and P. anomala. Two out of the four remaining ORFs show weak homology with different proteins from other species and the other two show non-significant similarity with previously sequenced genes. The nucleotide sequence has been submitted to the EMBL database under Accession No. AJ306295.

Analysis of 41 kb of the DNA sequence from the right arm of chromosome II of Schizosaccharomyces pombe

We report the complete sequence of cosmid c18A7 (41 046 bp insert), located on the right arm of chromosome II of the Schizosaccharomyces pombe genome. The sequence, which partially overlaps with cosmids SPBC4F6 and SPBC336, contains 16 open reading frames (ORFs) capable of coding for proteins of at least 100 amino acid residues in length (one partial) and one small nucleolar RNA (snoRNA). Four known genes were found: swi10 (encoding a mating-type switching protein also involved in nucleotide excision repair); dim1 (encoding a dimethyladenosine transferase); arf1 (encoding ADP-ribosylation factor 1); and pol3 (cdc6) the partial fragment, encoding the 125 kDa catalytic subunit of the DNA polymerase type B. Six ORFs similar to known proteins were found. They include a transporter of the major facilitator superfamily class, a vacuolar sorting protein, an asparagine synthase, a nuclear protein, a reticulum oxidoreductin and a heat shock protein. Each protein product of the other six ORFs has conserved domains and can be assigned a molecular, but not a biological, function. The sequence has been submitted to the EMBL database under Accession No. AL080287.

Multicenter randomized study comparing initial daily induction with high dose lymphoblastoid interferon vs. standard interferon treatment for chronic hepatitis C

One hundred fifty-five chronic hepatitis C patients were assigned at random to receive natural lymphoblastoid interferon (IFN)alpha-n1, s.c., for 13 months in one of three treatment regimens: initial daily induction with 10 million units (MU) followed (group 1, n = 50) or not (group 2, n = 52) by 1 month of rest and then three times weekly 10 MU (2 months), 5 MU (2 months), and 3 MU (8 months); group 3 (n = 53) received tiw 5 MU (2 months) followed by 3 MU (11 months). By intention-to-treat analysis, ALT normalization at completion of treatment was greater in patients who received continuous IFNalpha-n1 therapy with initial daily induction (group 2: 24/52, 46%) compared with those given intermittent therapy with initial daily induction (group 1: 17/50, 34%) and those who received standard IFNalpha-n1 therapy (group 3, 18/53, 34%; P not significant). The sustained ALT response was 26%, 27% and 21% and the sustained virological response was 20%, 27%, and 19%, in groups 1, 2, and 3, respectively. A trend was observed towards a higher biochemical and virological end-of-treatment response in patients given induction therapy (17%) compared with standard therapy (6%, P = 0.053). Sustained biochemical and virological responses were 20%, 27%, and 17% in groups 1, 2, and 3, respectively. Platelet and leukocyte counts decreased following daily high-dose treatment and remained low until therapy cessation (P < 0.001). The data suggest that daily s.c. induction with 10 MU IFNalpha-n1 followed by intermittent or continuous maintenance therapy for 1 year does not improve the results achieved with the standard 1-year IFNalpha course in the treatment of chronic hepatitis C patients.

Two-stage cultures for the production of astaxanthin from Haematococcus pluvialis

A two-stage culture system was established for the production of astaxanthin from Haematococcus pluvialis. In a first stage green vegetative cells were produced in semicontinuous cultures maintained with daily renewal rates between 10 and 40%. The steady-state cell density decreased with increasing renewal rates. Highest cell productivity, 64 x 10(6) cells l(-1) day(-1) was obtained with a daily renewal rate of 20%. In a second stage the harvested cultures were submitted to high light (240 micromol photon m(-2) s(-1)) under batch conditions for 15 days in order to stimulate the transition to the aplanospore stage and the accumulation of astaxanthin. No decrease in cell density was recorded during the induction period in any of the cultures. Cultures obtained at high renewal rates continued growing during the induction period and no astaxanthin was accumulated until all nitrogen in the media had been consumed. The final concentration of astaxanthin was inversely correlated to the growth rate at which first-stage cultures were maintained. Optimal renewal rate for maximal astaxanthin production depended on the duration of the induction period. After a 12-day induction period the highest astaxanthin production, 5.8 mg l(-1) of semi-continuous culture day -1, was obtained with cultures maintained at a renewal rate of 20%. When the induction period was increased to 15 days maximal astaxanthin productivity, 9.6 mg l(-1) of semi-continuous culture day -1, was obtained from cultures maintained at a renewal rate of 40% despite the much lower astaxanthin concentration achieved in these cultures. Results demonstrate the feasibility of semi-continuous cultivation of H. pluvialis for the two-stage production of astaxanthin.

Confirmed interruption of indigenous measles transmission in Catalonia

From November 1998 to December 2000, 84 suspected measles cases were reported in Catalonia (6 090 040 inhabitants). Of the 73 laboratory tested cases (87%), 20 showed IgM antibodies specific to measles and 3 were epidemiologically linked to a confirmed case. Among these 23 confirmed cases, 13 were indigenous, the last two cases reported dating back from June 1999 and July 2000. These results confirm the success of the measles elimination programme implemented in 1998 in Catalonia.

Confirmed interruption of indigenous measles transmission in Catalonia

From November 1998 to December 2000, 84 suspected measles cases were reported in Catalonia (6 090 040 inhabitants). Of the 73 laboratory tested cases (87%), 20 showed IgM antibodies specific to measles and 3 were epidemiologically linked to a confirmed case. Among these 23 confirmed cases, 13 were indigenous, the last two cases reported dating back from June 1999 and July 2000. These results confirm the success of the measles elimination programme implemented in 1998 in Catalonia.

Confirmed interruption of indigenous measles transmission in Catalonia

From November 1998 to December 2000, 84 suspected measles cases were reported in Catalonia (6 090 040 inhabitants). Of the 73 laboratory tested cases (87%), 20 showed IgM antibodies specific to measles and 3 were epidemiologically linked to a confirmed case. Among these 23 confirmed cases, 13 were indigenous, the last two cases reported dating back from June 1999 and July 2000. These results confirm the success of the measles elimination programme implemented in 1998 in Catalonia.

Gene order in a 10 275 bp fragment of Yarrowia lipolytica, including adjacent YlURA5 and YlSEC65 genes conserved in four yeast species

We have determined the sequence of a 10275 bp DNA segment of Yarrowia lipolytica located on chromosome VI. The sequence contains six complete open reading frames (ORFs) longer than 100 amino acids and two more partial ORFs at both ends. Two of the ORFs encode for the well-characterized genes YlURA5 (orotate phosphoribosyltransferase) and YlSEC65 (encoding a subunit of the signal recognition particle). These two genes show an identical organization-located on opposite strands and in opposite orientations-in four yeast species: Saccharomyces cerevisiae, Kluyveromyces lactis, Candida albicans and Y. lipolytica. One ORF and the two partial ORFs code for putative proteins showing significant homology with proteins from other organisms. YlVI-108w (partial) and YlVI-103w show 39% and 54% identity, respectively, with YDR430c and YHR088w from S. cerevisiae. YlVI-102c (partial) shows significant homology with a matrix protein, lustrin A from Haliotis rufescens, and with the PGRS subfamily (Gly-rich proteins) of Mycobacterium tuberculosis. The three remaining ORFs show weak or non-significant homology with previously sequenced genes. The nucleotide sequence has been submitted to the EMBL database under Accession No. AI006754.

The seroepidemiology of B. pertussis infection in Catalonia, Spain

A survey of the seroprevalence of pertussis antibodies in a representative sample of the population from Catalonia was carried out. Ninety-seven municipalities and 30 schools were randomly selected to recruit the 2126 subjects who participated in the study. A serum sample was obtained from all individuals participating in the study in order to determine levels of pertussis toxin (PT) and filamentous hemagglutinin (FHA) antibodies by ELISA test. Sociodemographic data were collected for all subjects. The prevalence of PT antibodies was 75% and that of FHA antibodies 89%. Significant increments were observed with age, both in the prevalence of PT (P < 0.0001) and of FHA (P = 0.018). Of the sociodemographic variables studied, only urban habitat was significantly associated to PT antibodies. The agreement observed among the two types of antibodies studied was weak (K = 0.264). Routine revaccination with the acellular vaccine in children over 7 years of age, in adolescents and adults seems a reasonable strategy to prevent the appearance of cases of pertussis in the community.

Gas chromatographic study of the volatile products from co-pyrolysis of coal and polyethylene wastes

The aim of this study was to determine the volatile products distribution of co-processing of coal with two plastic wastes, low-density polyethylene from agriculture greenhouses and high-density polyethylene from domestic uses, in order to explain the observed decrease in coal fluidity caused by polyethylene waste addition. Polymeric materials, although they are not volatile themselves, may be analysed by gas chromatography through the use of pyrolysis experiments. In this way, a series of pyrolysis tests were performed at 400 and 500 degrees C in a Gray-King oven with each of the two plastic wastes, one high-volatile bituminous coal and blends made up of coal and plastic waste (9:1, w/w, ratio). The pyrolysis temperatures, 400 and 500 degrees C, were selected on the basis of the beginning and the end of the coal plastic stage. The organic products evolved from the oven were collected, dissolved in pyridine and analysed by capillary gas chromatography using a flame ionization detector. The analysis of the primary tars indicated that the amount of n-alkanes is always higher than that of n-alkenes and the formation of the alkenes is favoured by increasing the pyrolysis temperature. However, this effect may be influenced by the size of the hydrocarbon. Thus, the fraction C17-C31 showed a higher increase of n-alkenes/n-alkanes ratio than other fractions. On the other hand, the difference between the experimental and estimated values from tars produced from single components was positive for n-alkanes and n-alkenes, indicating that co-pyrolysis of the two materials enhanced the chemical reactivity during pyrolysis and produced a higher conversion than that from individual components.