Francisca molina - Academia.edu (original) (raw)

Papers by Francisca molina

Diagnostic Microbiology and Infectious Disease, 2004

A total of 123 genetically-unrelated strains of Enterococcus spp. strains (51 Enterococcus faecal... more A total of 123 genetically-unrelated strains of Enterococcus spp. strains (51 Enterococcus faecalis, 57 Enterococcus faecium, 10 Enterococcus gallinarum, and 5 Enterococcus casseliflavus) were phenotypically identified by biochemical profiles and by using an automated method. The strains were also analyzed by a PCR assay to assess the accuracy of the phenotypically-based methods for identification of Enterococcus spp. With this aim, a PCR assay using different cell targets, which allows simultaneous detection of glycopeptide-resistant genotypes as well as identification to the species level by means of different gene targets, was used as the gold standard method. All 51 strains of E. faecalis were correctly identified, whereas 48 of 57 strains (84.2%) of E. faecium, were correctly identified. All of the strains of E. gallinarum and 3 out of 5 strains of E. casseliflavus were also correctly identified. The overall results showed that it is possible to identify Enterococcus spp. at the molecular level in less than 30 hours, compared with the 48-96 hours required for the phenotypically-based methods. The excellent accuracy of the PCR assay in identifying these species, particularly E. faecium, must also be emphasized. These findings may have implications for the routine clinical identification of enterococci species.

Antimicrobial Agents and Chemotherapy, 2004

Diagnostic Microbiology and Infectious Disease, 2004

an increase in the number of Klebsiella pneumoniae isolates with reduced susceptibility to expand... more an increase in the number of Klebsiella pneumoniae isolates with reduced susceptibility to expanded-spectrum cephalosporins (RSKp) was detected in the neonatal unit of the Juan Canalejo Hospital, and 21 patients were either colonized or infected by the bacterial isolates. The current "gold standard" method for typing K. pneumoniae isolates is pulsed-field gel electrophoresis. However, this technique is expensive and time-consuming.

Antimicrobial Agents and Chemotherapy, 2004

Objectives: To evaluate the performance of oxacillin, cefazolin, cefoxitin, cefotaxime and imipen... more Objectives: To evaluate the performance of oxacillin, cefazolin, cefoxitin, cefotaxime and imipenem discs; Etest for oxacillin; microdilution; agar screening plates with 2 and 6 mg/L of oxacillin; and PBP2 0 agglutination for detection of methicillin-resistant Staphylococcus aureus (MRSA).

Antimicrobial Agents and Chemotherapy, 2004

Journal of Clinical Microbiology, 2002

During the course of a molecular epidemiology study of mechanisms of antibiotic resistance in the... more During the course of a molecular epidemiology study of mechanisms of antibiotic resistance in the area served by our hospital (516,000 inhabitants), we isolated the gene encoding CTX-M-14 ␤-lactamase. Thirty clinical strains (27 Escherichia coli and 3 Klebsiella pneumoniae isolates) with a phenotype of extended-spectrum ␤-lactamase were collected from January to October 2001 and studied for the presence of the CTX-M-14 ␤lactamase gene. By isoelectric point determination, PCR, and nucleotide sequencing, we detected the presence of this gene in 17 E. coli strains belonging to 15 different genotypes (REP-PCR) causing infections in 17 different patients. Epidemiological studies based on medical records did not suggest any relationship between the patients infected with these E. coli strains and, interestingly, 7 of 30 patients harboring strains with extended-spectrum ␤-lactamases never had contact with the hospital environment before the clinical E. coli isolation. Conjugation experiments revealed that this gene was plasmid mediated in the 17 E. coli strains, and plasmid restriction fragment length polymorphisms showed 9 different patterns in the 17 E. coli strains. By PCR, the sequence of the tnpA transposase gene of the insert sequence ISEcp-1 was detected in all the plasmids harboring the CTX-M-14 gene. These results strongly suggest that plasmid dissemination between different E. coli strains in addition to a mobile element (transposon) around the ␤-lactamase gene may be involved in the spreading of the CTX-M-14 gene. This study reinforces the hypothesis that the epidemiology of the prevalence of the ␤-lactamase genes is changing and should alert the medical community to the increase in the emergence of the CTX-M ␤-lactamases worldwide.