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C Latorre

Publications and source records attributed to C Latorre.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Diagnosis of tuberculosis in children. Evaluation of the PCR technique].

OBJECTIVE: The purpose of this study was to evaluate the usefulness of the technique of polymerase chain reaction (PCR) for the diagnosis of tuberculosis in the pediatric population. PATIENTS AND METHODS: All patients seen at the University Hospital Sant Joan de Déu in Barcelona during the year of 1995 in which there was a clinical suspicion of or an interest in discarding tuberculosis were studied. Two types of diagnoses were considered: 1) Diagnosis from clinical evidence without microbiological confirmation, 2) A certain diagnosis including microbiological confirmation. All samples received at the microbiology laboratory were processed by baciloscopy, culture and PCR, Amplicor PCR M. tuberculosis was used as the PCR method. RESULTS: Sixty-four samples (most of them gastric juices) from 41 children were processed during the study period. Fourteen patients, between 8 months and 17 years of age, were diagnosed of tuberculosis, Microbiological confirmation by culture and/or PCR was obtained in four patients (31%). PCR was the only positive technique in one child (staining and culture negative) with clinical evidence of tuberculosis. All samples from the other three patients that had positive cultures also had positive PCR results. False positives were not detected. CONCLUSIONS: PCR improves the diagnosis of pediatric tuberculosis. It stands out because of its quickness (possibility of a 9 hour turn-around time), sensitivity (slightly higher than cultures in our series) and specificity.

Adolescent↗
PubMed1996

Serogroup-specific epidemiology of Streptococcus pneumoniae: associations with age, sex, and geography in 7,000 episodes of invasive disease.

A study sample of 7,010 episodes of invasive Streptococcus pneumoniae disease was obtained by combining 13 existing datasets. Disease episodes due to each of 12 pneumococcal serogroups (1, 3-9, 14, 18, 19, and 23) were then compared with episodes in a constant internal control group to describe serogroup-specific variations in disease frequency by age, sex, and geographic origin. The results are presented as odds ratios (with 95% confidence intervals) derived by logistic regression, with adjustment for the major confounders, including dataset of origin. Variation in the male:female ratios between serogroups is small, suggesting that capsular characteristics are an unlikely explanation for the male preference of S. pneumoniae. Serogroups associated with higher nasopharyngeal prevalence (e.g., 19 and 24) are relatively more common in Europe and North American, while the invasive serotypes 1 and 5 are much more common in South America. The custom of reporting serogroup frequencies in two age groups, children and adults, conceals much of the variation in the age distributions across the whole span of life. The reduction of risk associated with serogroups 6, 14, 18, 19, and 23 beyond childhood follows different gradients, being most abrupt in serogroups 14 and most gradual in serogroup 18. The relative risk of disease with serotype 1 declines steadily throughout life, while with serotypes 3 and 8 it increases over middle age. Serogroups 7 and 23 are found unusually frequently in the third decade of life. Because of the wide differences in the epidemiology of individual serogroups of S. pneumoniae, it is questionable whether pneumococcal infection should continue to be classified as a single disease entity.

Adolescent↗
PubMed1996

[Microbiological study of the respiratory tract in children with cystic fibrosis].

PURPOSE: Pulmonary infections is a main cause of morbimortality in patients suffering from cystic fibrosis. The objective of this study was to know the flora implicated in respiratory pathology of all mucoviscidotic children attending Hospital Sant Joan de Déu of Barcelona. METHODS: Quantitative cultures from respiratory samples (most of them: sputum) of 26 patients were performed from January 91 to June 93. There were 13 girls and 13 boys, aged 1 to 13 years (mean: 7 years). RESULTS: 282 microorganisms were isolated from 203 positive samples. Cultures of 88.4% of patients yielded in some moment Haemophilus influenzae, 82.6% of them Haemophilus parainfluenzae, 65.3% Pseudomonas aeruginosa, 50% Streptococcus pneumoniae, 38.4% Staphylococcus aureus. The most prevalent microorganism was P. aeruginosa (66%) followed by H. influenzae (29%) and S. aureus (26.6%). 59% of P. aeruginosa strains showed a mucoid phenotype. CONCLUSIONS: Haemophilus sp. causes short term infections that affect children of all ages, whereas infections due to P. aeruginosa persist in spite of correct antimicrobial therapy.

Adolescent↗
PubMed1995

[Evaluation of the E test method in the antimicrobial sensitivity of Neisseria meningitidis to penicillin].

BACKGROUND: The E test (AB Biodisk, Solna, Sweden) is a rather new method for performing antimicrobial susceptibility test--their results are generated directly as MICs. Due to its simplicity, is available in nearly all laboratories. The present study evaluates the effectiveness of the E test for susceptibility studies of Neisseria meningitidis to penicilline. METHODS: The MICs of penicilline of 55 strains of Neisseria meningitidis, studied by E test and by microdilution method, were compared to those obtained by agar dilution using both Mueller-Hinton (MH) and Mueller-Hinton with a 5% of sheep blood (MH+S) as test culture bases. RESULTS: The concordance rate (+/- 1 log2 of dilutions) was 100% in all cases, except for the E test on MH+S which yielded a 98.2% value. The Pearson's correlation coefficients were 0.95 and 0.84 for the E test and 0.88 and 0.85 for microdilution, using MH and MH+S. Roughly 70% of strains were considered susceptible to penicillin using MH for the in vitro tests, whereas only 40% of them were so considered using MH+S. CONCLUSIONS: The E test can be considered a good alternative to agar dilution method when testing susceptibility of N. meningitidis to penicilline, and MH is the best culture base for these assays.

Bacteriological Techniques↗
PubMed1992

[Osteoarticular infections in children].

We presented a retrospective review of osteoarticular infections diagnosed at Sant Joan de Deu Hospital from Barcelona, in the last 10 years (1981-1990). A total of 127 arthritis and 113 osteomyelitis were recorded in children aged from a few days to 15 years. This represents a 3.5% of all infectious diseases patients during the study period. The most common microorganism was S. aureus (52.3%) followed by Brucella (8.2%) and Salmonella as well as Streptococcus agalactiae (7.3% each). The most common involved joint were hip and knee in arthritis cases, but long bones (tibia and humerus) in osteomyelitis cases.

Adolescent↗
PubMed1991

Novel plasmids in clinical strains of Streptococcus pneumoniae.

Small plasmids were found in two clinical isolates of Streptococcus pneumoniae from Spain (strains 671 and 678) and in one strain (SpR) isolated in Germany. All three strains contained one plasmid (2.75 to 3.1 kb) which is related to the only previously described pneumococcal plasmid, pDP1. Strains 678 and SpR carried a second plasmid of 2.6 kb and 2.7 kb, respectively. These two plasmids hybridized neither with each other, nor with pDP1, demonstrating that they represent new types of plasmids not having been found in pneumococci before.

Blotting, Southern↗
PubMed1991

Variability of penicillin-binding proteins from penicillin-sensitive Streptococcus pneumoniae.

Penicillin-binding proteins (PBPs) from penicillin-susceptible strains of Streptococcus pneumoniae are believed to be fairly similar in contrast to PBPs occurring in resistant isolates. The antigenic variation of PBPs 1a and 2b in 65 penicillin-susceptible strains from different geographic areas and a wide variety of isolation sites was analyzed using a set of specific antisera and monoclonal antibodies. Three strains contained different antigenic variants of PBP 1a, and 50 strains contained one of three antigenic variants found in PBP 2b. Seven patterns of antibody reactivity could be defined; all but one were distinct from those found recently in resistant strains. In addition, electrophoretic mobilities of all six PBPs, compared after conventional SDS-PAGE and fluorography, revealed an unexpected variation of PBP-profiles even for strains of one sero-group. Few strains appeared identical to each other or to the laboratory reference strain R6.

Antibodies, Bacterial↗
PubMed1991

Antigenic variation of penicillin-binding proteins from penicillin-resistant clinical strains of Streptococcus pneumoniae.

Penicillin-resistant strains of Streptococcus pneumoniae that are isolated with increasing frequency worldwide contain low-affinity penicillin-binding proteins (PBPs). The relatedness of PBPs from 55 resistant strains isolated on three continents was investigated by testing the reactivity of antibodies specific for PBP 1a or 2b and by comparing the PBP patterns. Seventeen patterns of antibody reactivity could be distinguished, 12 of which were specific to one isolate. Most strains, including all German and South African strains, had a unique PBP profile. A few groups of Spanish and Finnish isolates were identified where the strains within each group shared the same PBP profile, the same antigenic variants of PBPs 1a and 2b, and the same serogroup, suggesting that they represent different clones of S. pneumoniae. The results demonstrated highly variable pathways of resistance development and confirmed that resistant strains have emerged independently in different locations.

Antibodies, Bacterial↗
PubMed1987

Neisseria meningitidis strains with decreased susceptibility to penicillin.

Neisseria meningitidis strains relatively resistant to penicillin were recovered from blood or cerebrospinal fluid cultures of four children treated in Barcelona, Spain, and surrounding areas. The four strains had distinct serogrouping and serotyping patterns. The minimal inhibitory concentrations of penicillin were 0.25 microgram/ml for three strains and 0.5 microgram/ml for the fourth strain. These are the first relatively penicillin-resistant meningococcal strains identified in Spain.

Child↗
PubMed1986

Isolation and characterization of nitrogenase-derepressed mutant strains of cyanobacterium Anabaena variabilis.

A positive selection method for isolation of nitrogenase-derepressed mutant strains of a filamentous cyanobacterium, Anabaena variabilis, is described. Mutant strains that are resistant to a glutamate analog, L-methionine-D,L-sulfoximine, were screened for their ability to produce and excrete NH4+ into medium. Mutant strains capable of producing nitrogenase in the presence of NH4+ were selected from a population of NH4+-excreting mutants. One of the mutant strains (SA-1) studied in detail was found to be a conditional glutamine auxotroph requiring glutamine for growth in media containing N2, NO3-, or low concentrations of NH4+ (less than 0.5 mM). This glutamine requirement is a consequence of a block in the assimilation of NH4+ produced by an enzyme system like nitrogenase. Glutamate and aspartate failed to substitute for glutamine because of a defect in the transport and utilization of these amino acids. Strain SA-1 assimilated NH4+ when the concentration in the medium reached about 0.5 mM, and under these conditions the growth rate was similar to that of the parent. Mutant strain SA-1 produced L-methionine-D,L-sulfoximine-resistant glutamine synthetase activity. Kinetic properties of the enzyme from the parent and mutant were similar. Mutant strain SA-1 can potentially serve as a source of fertilizer nitrogen to support growth of crop plants, since the NH4+ produced by nitrogenase, utilizing sunlight and water as sources of energy and reductant, respectively, is excreted into the environment.

Ammonia↗