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P Coll

Publications and source records attributed to P Coll.

At least 37 records · Page 2Linked to original sources
PubMed2001

Molecular and conventional epidemiology of tuberculosis in an inner city district.

SETTING: Molecular epidemiology has underlined the importance of recent tuberculosis (TB) transmission and has uncovered notable discrepancies compared with conventional epidemiology. OBJECTIVES: 1) To determine, by RFLP analysis, the percentage of clustered cases in an inner city district with a high incidence of TB (163/100,000) and the groups at risk of being clustered; and 2) to compare the role of conventional contact tracing (CCT) with that of RFLP. DESIGN: RFLP was carried out using the IS6110 and pTBN12 (PGRS) sequences of 165 cultures positive for Mycobacterium tuberculosis in the Ciutat Vella district of Barcelona during 1997-1998. Contact tracing was carried out in 171 of 251 declared cases (68.1%). Associations were assessed by calculating odds ratios (OR) with 95% confidence intervals (CI). Logistic regression was used for multivariate analysis. RESULTS: Using RFLP, 76 (46.0%) strains were found to be clustered by IS6110 and PGRS. From CCT, 30 new patients were found among 858 contacts (3.5%) and 57 patients were linked. In terms of RFLP and CCT, the main risk factor was intravenous drug use (IVDU). In 44 cases who lived alone and were not involved in CCT, 50% were in RFLP clusters. The concordance rate between RFLP and CCT was 8/13 (61.5%); the disagreement corresponded to a cluster of five recent immigrants from Africa. Subsequent to RFLP, an epidemiological connection was found in 15/55 cases (27.2%). CONCLUSIONS: The percentage of clustered cases is very high. CCT was useful for identifying new cases, but it was insufficient for detecting the pathways of transmission. CCT coverage needs to be improved in marginalized individuals, and the results correlated with those of RFLP.

Adolescent↗
PubMed2000

[Drug resistance in Mycobacterium tuberculosis. A multicenter study of the Barcelona area. Grupo de Trabajo sobre Resistencias en Tuberculosis].

BACKGROUND: The aims of this multicenter study was to establish the level of primary and acquired drug resistance of M. Tuberculosis strains isolated in Barcelona and to identify possible risk groups using clinical data. PATIENTS AND METHODS: All tuberculosis patients with isolation and identification of M. tuberculosis strains from October 1995 to September 1997 were included. Susceptibility tests isoniazid, rifampin, ethambutol, streptomycin and pyrazinamide were performed using the Bactec 460 system and the proportions method on solid medium. Logistic progression was used for statistical analysis. RESULTS: The total number of patients included was 1,749 (1,535 non-treated and 214 previously treated). Primary drug resistance was 5.7% (isoniazid 3.8%; rifampin 1.0%, streptomycin 2.1%, ethambutol 0.3% and pyrazinamide 1.0%). Acquired drug resistance was 20.5% (isoniazid 17.3%, rifampin 9.8%, ethambutol 1.9%, streptomycin 4.7% and pyrazinamide 6.5%). Primary drug resistance was associated with people over 60 years old and women. CONCLUSIONS: The low level of drug resistance enables antituberculosis treatment of non-treated patients to start with the standardised three-drug regimes except in the case of foreign people from countries with a high level of drug resistance. Susceptibility tests are recommended on all M. tuberculosis strains isolated, together with controlled studies of drug resistance surveillance.

Adolescent↗
PubMed2000

Predictors of tuberculosis transmission in prisons: an analysis using conventional and molecular methods.

OBJECTIVE: To determine the tuberculosis (TB) transmission patterns within the prison system in Catalonia, conventional epidemiological techniques were combined with DNA fingerprinting of Mycobacterium tuberculosis. METHODS: IS6110- and polymorphic GC-rich repeat sequence (PGRS)-based restriction fragment length polymorphism (RFLP) were combined with epidemiological studies to assess the relatedness of isolates from all patients with confirmed TB at five prisons in the province of Barcelona (Catalonia, Spain), between 1 July 1994 and 31 December 1996. Risk factors for transmission were analysed to a logistic regression. The extent of drug-resistant TB was also assessed. RESULTS: The incidence of TB during the study period was 2775 cases per 100,000 inmate years. Of the 247 culture-positive cases, 126 (51%) appeared to have active TB as a result of recent transmission. Using conventional epidemiological methods, 14 active chains of transmission were identified in prison involving 65 isolates (52% of clustered patients). A lengthy history of imprisonment [odds ratio (OR) 2.8, 95% confidence interval (CI) 1.52-5.11] and pulmonary TB (OR 2.36, 95% CI 1.17-4.75) were independently associated with clustering. Low rates of both initial (2.9%) and acquired drug resistance (5.8%) were identified and there was no evidence of the transmission of drug-resistant TB. CONCLUSION: In the prison system studied, the recent transmission of TB contributes substantially to the overall incidence of the disease. Both lengthy incarcerations and delays in identifying inmates with pulmonary symptoms play a key role in this recent transmission. Directly observed therapy (DOT) is a critical control strategy for reducing the emergence of drug resistance and for avoiding the transmission of resistant organisms.

Adolescent↗
PubMed2000

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.

Anti-Bacterial Agents↗
PubMed2000

Epidemiology of community-acquired pneumonia in adults: a population-based study.

In this prospective study, the authors assessed the incidence, aetiology, and outcome of patients with community-acquired pneumonia in the general population. From December 1993 to November 1995, a study was performed in a mixed residential-industrial urban population of the "Maresme" region in Barcelona, Spain. All subjects > or =14 yrs of age (annual average population size 74,368 inhabitants) with clinically suspected community-acquired pneumonia were registered. All cases were re-evaluated by chest radiographs on the 5th day of illness and at monthly intervals until complete recovery. Urine and blood samples were obtained for culture and antigen detection. When lower respiratory tract secretions were obtained, these were also cultured. There were 241 patients with community-acquired pneumonia, with an annual incidence rate of 1.62 cases (95% confidence interval, 1.42-1.82) per 1,000 inhabitants. Incidence rates increased by age groups and were higher in males than in females. Of 232 patients with aetiological data, 104 had an identifiable aetiology. A total of 114 pathogens were found (single pathogen 94, two pathogens 10). There were 81 episodes of bacterial infection and 33 of viral infection. The most common pathogens were Streptococcus pneumoniae, Chlamydia pneumoniae, and influenza A and B viruses. No case of Hantavirus infection was found. The rate of hospital admission was 61.4% with a mean+/-SD length of 11.7+/-10.1 days, a mean period of 23.0+/-14.3 days inactivity, and an overall mortality rate of 5%. The high rate of hospital admission, prolonged stay in hospital, and long period of inactivity all continue to constitute a social and health care burden of community-acquired pneumonia.

Adolescent↗
PubMed2000

Cutaneous infections due to nontuberculous mycobacteria: histopathological review of 28 cases. Comparative study between lesions observed in immunosuppressed patients and normal hosts.

To evaluate the histopathological features observed in patients with cutaneous infections due to nontuberculous mycobacteria (NTM) and to compare the histopathological patterns observed in immunosuppressed patients and normal hosts. Twenty-eight biopsy specimens corresponding to 27 patients with cutaneous infections due to NTM were reviewed. Eighteen biopsies corresponded to normal hosts (14 Mycobacterium marinum, 2 Mycobacterium chelonae, 1 Mycobacterium terrae and 1 Mycobacterium gordonae) and 10 biopsy specimens were obtained from 9 immunosuppressed patients (3 Mycobacterium chelonae, one of which had two biopsies, 1 Mycobacterium abscessus, 2 Mycobacterium kansasii, 1 Mycobacterium marinum, 1 Mycobacterium avium complex and 1 Mycobacterium simiae). A panel of histopathological features was evaluated by two independent observers in each biopsy specimen. Epidermal changes (acanthosis, pseudoepitheliomatous hyperplasia, exocytosis) were mainly observed in M. marinum infections. In immunosuppressed patients the infiltrate tended to be deeper, involving the subcutaneous tissue (100%) with a more diffuse distribution and constant abscess formation. A marked granulomatous inflammatory reaction was observed in 83% of immunocompetent and in 60% of immunosuppressed patients. In immunosuppressed patients a relationship between the chronic evolution of the disease and granuloma formation was demonstrated. A diffuse infiltrate of histiocytes with occasionally foamy appearance was noted in three biopsy specimens from three patients with AIDS. Acute and chronic panniculitis was detected in 8 biopsy specimens. In one biopsy (M. chelonae) an acute suppurative folliculitis was observed. Different histopathological patterns can be noted in biopsy specimens from cutaneous nontuberculous mycobacterial infections. The evolution of the disease and the immunologic status of the host may explain this spectrum of morphological changes. Tuberculoid, palisading and sarcoid-like granulomas, a diffuse infiltrate of histiocytic foamy cells, acute and chronic panniculitis, non-specific chronic inflammation, cutaneous abscesses, suppurative granulomas and necrotizing folliculitis can be detected. Suppurative granulomas are the most characteristic feature in skin biopsy specimens from cutaneous NTM infections. Some histopathological patterns seem more prevalent in immunosuppressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Escherichia coli serotype O15:K52:H1 as a uropathogenic clone.

To clarify the clinical and bacteriological correlates of urinary-tract infection (UTI) due to Escherichia coli O15:K52:H1, during a 1-year surveillance period we prospectively screened all 1, 871 significant E. coli urine isolates at the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain, for this serotype and assessed the epidemiological features of community-acquired UTI due to E. coli O15:K52:H1 versus other E. coli serotypes. We also compared the 25 O15:K52:H1 UTI isolates from the present study with 22 O15:K52:H1 isolates from other, diverse geographic locales and with 23 standard control strains (8 strains from the ECOR reference collection and 15 strains of nonpathogenic O:K:H serotypes) with respect to multiple phenotypic and genotypic traits. Although E. coli O15:K52:H1 caused only 1.4% of community-acquired E. coli UTIs during the surveillance period, these UTIs were more likely to present as pyelonephritis and to occur in younger hosts, with similar risk factors, than were UTIs due to other E. coli serotypes. Irrespective of geographic origin, E. coli O15:K52:H1 strains exhibited a comparatively restricted repertoire of distinctive virulence factor profiles (typically, they were positive for papG allele II, papA allele F16, and aer and negative for sfa, afa, hly, and cnf1), biotypes, ribotypes, and amplotypes, consistent with a common clonal origin. In contrast, their antimicrobial resistance profiles were more extensive and more diverse than those of control strains. These findings indicate that E. coli O15:K52:H1 constitutes a broadly distributed and clinically significant uropathogenic clone with fluid antimicrobial resistance capabilities.

Bacteremia↗
PubMed2000

Comparison of IS1245 restriction fragment length polymorphism and pulsed-field gel electrophoresis for typing clinical isolates of Mycobacterium avium subsp avium.

SETTING: Little is still known about the epidemiology and pathogenesis of Mycobacterium avium subsp avium (MASA) infection. OBJECTIVE: Examination of the reproducibility and the stability over time of pulsed-field gel electrophoresis (PFGE) and IS1245 restriction fragment length polymorphism (IS1245-RFLP) techniques. The ability of these typing systems for differentiating clinical isolates of MASA was also assessed. DESIGN: Clinical isolates recovered from 63 patients (59 human immunodeficiency virus [HIV] positive and four HIV-negative) were studied by insertion sequence IS1245 and PFGE. For the study of in vivo and in vitro stability, strains collected over time from four patients and five strains chosen at random, respectively, were used. RESULTS: The stability of PFGE and IS1245-RFLP in vitro was excellent. PFGE was also stable in vivo, but IS1245-RFLP patterns showed some variation. The discriminatory power of IS1245-RFLP and PFGE was 0.995 and 0.989, respectively. The cluster analysis did not reveal differences between strains recovered from HIV-negative and HIV-positive patients or between patients with colonisation, local infection or disseminated disease. CONCLUSION: IS1245-RFLP and PFGE are useful tools for typing MASA strains. However, IS1245 variations in vivo may complicate the analysis of epidemiological relationships.

Adult↗
PubMed1999

Comparison of conventional ribotyping and PCR-RFLP ribotyping for the analysis of endemic strains of Neisseria meningitidis isolated in a local community over 7 years.

Conventional ribotyping was compared with the PCR amplification of the intergenic spacer region between 16S and 23S rRNA genes (PCR-RFLP ribotyping) when applied to the subtyping of sporadic Neisseria meningitidis strains. Thirty isolates out of a total of 36 meningococcal disease cases, reported as having occurred in a particular community over a 7-year endemic period, were analyzed by each of the methods. Only ribotyping with three restriction enzymes (EcoRI, ClaI and XhoI) gave acceptable discriminatory power for short-term epidemiological purposes. We conclude that conventional ribotyping is a suitable method for typing sporadic meningococcal strains and that it cannot be replaced by the more straightforward PCR-RFLP ribotyping method.

Bacterial Typing Techniques↗
PubMed1999

[Gastrointestinal disease with elevated plasma homocysteine level].

Elevated plasma homocystein (tHcy) is a marker for functional deficiency of folate and/or cobalamin. Malabsorption of these vitamins occurs in various gastroenterologic diseases. A frequent mutation (C677T) in the gene coding for the enzyme methyltetrahydrofolate reductase (MTHFR) is often associated with elevated values of tHcy. We have investigated 24 patients with tHcy > 40 mumol/l for gastrointestinal disease that can contribute to such elevation. Of these, 19 were homozygous for mutated MTHFR, four were heterozygous and one was normal. We found two cases of probable celiac disease, one case of Crohn's disease and one case of ulcerative colitis. These four were homozygous for the C667T mutation. Furthermore, we found eight persons who were anacidic; four homozygous, three heterozygous and one normal. All had gastritis histologically, six had serum gastrin > 50 pmol/l, and four were already on treatment with cobalamin injections. Helicobacter pylori-infection was found in nine out of 22 persons. Gastrointestinal disease occurs frequently in patients with tHcy > 40 mumol/l, but with the exception of conditions resulting in serious deficiency of cobalamin, these diseases alone do not seem sufficient to cause such high levels. We suggest that a reasonable approach to patients with homocystein values above 40 mumol/l is to exclude cobalamin deficiency, and that further investigations should be based upon thorough anamnesis and symptoms.

Biomarkers↗
PubMed1999

New insights into Titan's organic chemistry in the gas and aerosol phases.

Titan, the largest satellite of Saturn, with a dense atmosphere very rich in organics, and many couplings in the various parts of its "geofluid", is a reference for studying prebiotic chemistry on a planetary scale. New data have been obtained from experiments simulating this organic chemistry (gas and aerosol phases), within the right ranges of temperature and a careful avoiding of any chemical contamination. They show a very good agreement with the observational data, demonstrating for the first time the formation of all the organic species already detected in Titan atmosphere including, at last, C4N2, together with many other species not yet detected in Titan. This strongly suggests the presence of more complex organics in Titan's atmosphere and surface, including high molecular weight polyynes and cyanopolyynes. The NASA-ESA Cassini-Huygens mission has been successfully launched in October 1997. The Cassini spacecraft will reach the Saturn system in 2004 and become an orbiter around Saturn, while the Huygens probe will penetrate into Titan's atmosphere. In situ measurements, in particular from Huygens GC-MS and ACP instruments, will provide a detailed analysis of the organics present in the air, aerosols, and surface. This very ambitious mission should yield much information of crucial importance for our knowledge of the complexity of Titan's chemistry, and, more generally for the field of exobiology.

Aerosols↗
PubMed1999

Spiramycin is comparable to oxytetracycline in eradicating H. pylori when given with ranitidine bismuth citrate and metronidazole.

BACKGROUND: We have consistently achieved about 90% eradication of H. pylori with liquid bismuth, metronidazole and oxytetracycline. AIM: To test eradication and adverse events of ranitidine bismuth citrate (RBC) when given with metronidazole and either oxytetracycline or spiramycin. METHODS: One hundred and eighty-three patients were randomized to one of four 10-day regimens: RBC400OM: RBC 400 mg b.d., oxytetracycline 500 mg q.d.s.; RBC400SM: RBC 400 mg b.d., spiramycin 1 g q.d.s.; RBC200OM: RBC 200 mg q.d.s., oxytetracycline 500 mg q.d.s.; RBC200SM: RBC 200 mg q.d.s., spiramycin 1 g q.d.s. Additionally, all patients received metronidazole 400 mg q.d.s. A 14C-urea breath test was performed at 8 weeks. RESULTS: Intention-to-treat eradication rates were 94%, 91%, 94% and 89% with RBC400OM, RBC400SM, RBC200OM and RBC200SM, respectively (P = 0.81). Eradication was significantly higher in ulcer patients (97%) than in those with diagnoses other than ulcer (86%) (P = 0.009). There was a strong tendency to better eradication among those who had never smoked (100%) compared with ex-smokers (93%) and smokers (89%) (P = 0.06). Fifty-three per cent experienced at least one moderate or severe adverse event, and women had more adverse events than men (P = 0.0002). CONCLUSIONS: All four regimens had comparable efficacy and adverse events. Eradication was significantly better in ulcer patients but there was a trend to better eradication in those who smoked less, used less alcohol and exercised more. Adverse events were frequent, perhaps because of the large dose of metronidazole used, but few patients stopped treatment.

Adult↗
PubMed1998

Translocated intestinal bacteria cause spontaneous bacterial peritonitis in cirrhotic rats: molecular epidemiologic evidence.

BACKGROUND/AIMS: Intestinal bacterial translocation is common in cirrhotic rats with spontaneous bacterial peritonitis, and it is thought to play a major pathogenic role. There has so far been no evidence for clonality between bacteria isolated from intestine and ascites. This study aimed to use molecular epidemiology techniques to show that spontaneous bacterial peritonitis is due to translocated intestinal bacteria. METHODS: Samples of ascitic fluid, portal blood, mesenteric lymph nodes and ileal contents from healthy (n=10) and ascitic cirrhotic rats with (n=12) or without (n=15) spontaneous bacterial peritonitis were cultured. In six infected rats, DNA macrorestriction fragments of 30 bacterial isolates [Escherichia coli (n=13), Enterococcus faecalis (n=12) and Proteus mirabilis (n=5)] from ascites (n=8), mesenteric lymph nodes (n=7), portal blood (n=6), and ileal flora (n=9) were compared. RESULTS: Bacterial translocation was more frequent in animals with (58%) than in those without spontaneous bacterial peritonitis (20%, p=0.049) or controls (10%, p=0.026). The same bacterial strain was simultaneously isolated in ascites and in mesenteric lymph nodes and/or ileum in 7/8 (87%) instances. The identity rate for bacteria present in both ascites and mesenteric lymph nodes was 80% (4/5). Likewise, identity was demonstrated in 3/4 instances of bacteria found in both ascites and portal blood. CONCLUSIONS: These results indicate that spontaneous bacterial peritonitis in cirrhotic rats is mainly due to intestinal bacteria translocated to mesenteric lymph nodes. Portal blood could be a less frequent route.

Animals↗
PubMed1998

Review and latest results of laboratory investigations of Titan's aerosols.

Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N2 and CH4, and including many organics. This atmosphere also partly consists of hazes and aerosol particles which shroud the surface of this satellite, giving it a reddish appearance. The aerosols observed in Titan's atmosphere are thought to be synthesized at high altitudes (>300 km) and fall to the surface. Varying with temperature profiles, condensation phenomena take place in the lower atmosphere, about 100 km below. These solid particles, often called 'tholins', have been currently investigated for many years by laboratory scientists and physics modellers. This paper assesses past research and results in different fields (elemental composition, optical constants, pyrolysis, particle size), hightlighting interests and questions aroused by these studies. It also presents the latest results and advances, and concludes with existing problems and future pathways.

Aerosols↗
PubMed1998

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.

Adult↗
PubMed1998

Recurrent Pseudomonas aeruginosa pneumonia in ventilated patients: relapse or reinfection?

A prospective observational study was performed to determine whether recurrent episodes of pneumonia caused by Pseudomonas aeruginosa in ventilated patients were due to a relapse of the previous clone or to reinfection with a new one. Diagnosis was based on quantitative cultures of secretions obtained by bronchoscopy. Comparison of strains was made by chromosomal fingerprinting based on pulsed field gel electrophoresis (PFGE). Thirty-three (89.1%) of 37 patients survived the initial week after pneumonia diagnosis; six survivors (18.1%) had multiple episodes caused by the same species. Presence of adult respiratory distress syndrome (83.3% versus 22.2%, p = 0.02) was the only factor significantly associated with clinical recurrences. The 16 isolates from five patients (nine recurrences) were analyzed by PFGE. All new isolates from recurrent episodes, excepting one, were considered as relapses. These data suggest that most recurrent episodes of P. aeruginosa pneumonia in ventilated patients occur due to persistence of strains present in a prior infection.

Adult↗
PubMed1998

[Recurrent infection by Streptococcus agalactiae].

BACKGROUND: To study the factors implicated in the infectious process (host, microorganism and antibiotic) of a newborn early sepsis by S. agalactiae that suffered a reactivation at day five from discharge. METHODS: Description of two episodes of newborn sepsis by S. agalactiae corresponding to the same patient and microbiologic study of the isolated strain: typing by "genomic macrorestriction" and antibiotic tolerance by "timed killing curves". RESULTS: It was demonstrated that both strains of S. agalactiae type la/c belonged to the same clone as well as the tolerance to ampicillin of the strain. DISCUSSION: This sort of infections processes in the newborn are very serious and there is possibility of relapse. Thus, it is important to study the ethiologic agent and its relationship with antibiotics, in order to stablish the best treatment regimes, avoiding the possibility of relapses as the case we have described.

Adult↗