Prevalence of Chlamydia pneumoniae in the atherosclerotic plaque of patients with unstable angina and its relation with serology.

BACKGROUND: Chlamydia pneumoniae has been associated with coronary artery disease by both seroepidemiological studies, and by direct detection of the micro-organism in atherosclerotic lesions. This bacteria could play a potential role in the development of acute coronary events. We examined coronary arteries from patients with unstable angina in order to verify an endovascular presence of C. pneumoniae, and to determine if there is any relationship between serology of acute infection by this pathogen and its presence inside the atherosclerotic plaque of these patients. METHODS: We analysed a total of 76 atherosclerotic plaques obtained from 45 patients who underwent coronary artery bypass surgery. In all patients unstable angina was present within the prior 3 weeks. The presence of C. pneumoniae in the plaque was determined by nested polymerase chain reaction (PCR). Antichlamydial immunoglobulin G (IgG), A (IgA) and M (IgM) was examined by microimmunofluorescence and compared to the PCR result. FINDINGS: DNA of C. pneumoniae was detected in 57 (75%) of 76 atherosclerotic lesions. In most cases (74/76: 97%) a positive IgA, IgM or IgG result was seen. Seven (12%) and 54 (94%) of the 57 PCR positive plaques came from patients with a positive IgM and IgA result, respectively. There was no statistical significant difference between PCR positive and PCR negative plaques in patients with a positive or negative serological result. Clinical characteristics were similarly distributed in patients with and without infected lesions. INTERPRETATION: C. pneumoniae organisms are frequently found in the atherosclerotic lesions of patients undergoing coronary surgery for unstable angina. Neither serological results of acute or recent infection by C. pneumoniae nor clinical characteristics are useful in predicting the individual risk of harbouring C. pneumoniae in the coronary lesions of patients with unstable angina.

[Antimicrobial resistance surveillance: VIRA STUDY 2006]. / Vigilancia de resistencias a los antimicrobianos: estudio VIRA 2006.

INTRODUCTION: The objective of this study was to determine the current antimicrobial susceptibility patterns of the most frequent multi-resistant bacteria and to analyze any possible changes with respect to the two VIRA studies carried out in 2001 and 2004. METHODS: In February 2006, the 40 participating hospitals sent the following microorganisms: non-penicillin-susceptible Streptococcus pneumoniae (92), methicillin-resistant Staphylococcus aureus (MRSA) (290), clinically significant coagulase-negative staphylococci (136), ampicillin-resistant Enterococcus faecium (89), ampicillin-resistant Haemophilus influenzae (67), ciprofloxacin-resistant Escherichia coli (365), Pseudomonas aeruginosa (181), and Acinetobacter baumannii (92). The hospitals provided epidemiological data on these microorganisms. Susceptibility was determined with a broth microdilution method. RESULTS: Among the non-penicillin-susceptible S. pneumoniae isolates, the proportion of those ones resistant to this antibiotic showed a significant (p < 0.001) decrease (59.8% in 2001, 30.2% in 2004 and 14.3% in 2006). Among MRSA, we detected one isolate nonsusceptible to linezolid, four resistant to quinupristin-dalfopristin and one strain with a vancomycin MIC of 4 microg/mL. The prevalence of extended-spectrum beta-lactamase-producing E. coli was 12.1%. Resistance of A. baumannii to imipenem varied from 27% in the 2001-2004 period to 47.8% in 2006 (p < 0.005). CONCLUSION: These results again emphasize that resistance surveillance systems are an important tool for preventing the emergence and spread of multi-resistant pathogens.

[Surveillance of antimicrobial resistance: VIRA study 2004]. / Vigilancia de resistencias a los antimicrobianos: estudio VIRA 2004.

INTRODUCTION: The objective of the study was to know the current situation of the antimicrobial sensitivity patterns of the main multi-resistant bacteria and to analyze any possible changes with respect to the VIRA study carried out in 2001. METHODS: The 40 participating hospitals sent a total of 1,425 microorganisms isolated in February 2004, distributed as follows: penicillin-resistant Streptococcus pneumoniae (139), methicillin-resistant Staphylococcus aureus (289), clinically significant coagulase-negative staphylococci (158), ampicillin-resistant Enterococcus faecium (89) and Enterococcus faecalis (2), ampicillin-resistant Haemophilus influenzae (85), ciprofloxacin-resistant Escherichia coli (346), Pseudomonas aeruginosa (187), and Acinetobacter baumannii (130). The hospitals provided epidemiological data on these microorganisms. Sensitivity was determined by the broth microdilution method. RESULTS: The number of highly penicillin-resistant pneumococci fell significantly (p < 0.0001) compared with the previous study (from 59.8% to 30.2%). Global methicillin-resistance in S. aureus was 31.2%, which represents a significant increase (p < 0.001) compared with the year 2001 (24.8%). 11.3% of the E. coli strains were extended-spectrum beta -lactamase-producers and came from 24 hospitals. One P. aeruginosa isolate gave a positive result in the E-test MBL assay, suggesting the presence of metallo-beta -lactamases. The strains of imipenem-resistant A. baumannii presented cross-resistance with several antibiotics. CONCLUSION: These results show how the multi-resistant bacteria included in the study represent a growing problem in our hospitals. This emphasizes the importance of resistance surveillance systems and the correct use of antimicrobial agents.