Presence of bacterial DNA in thrombotic material of patients with myocardial infarction.

Infectious agents have been suggested to be involved in etiopathogenesis of Acute Coronary Syndrome (ACS). However, the relationship between bacterial infection and acute myocardial infarction (AMI) has not yet been completely clarified. The objective of this study is to detect bacterial DNA in thrombotic material of patients with ACS with ST-segment elevation (STEMI) treated with Primary Percutaneous Coronary Intervention (PPCI). We studied 109 consecutive patients with STEMI, who underwent thrombus aspiration and arterial peripheral blood sampling. Testing for bacterial DNA was performed by probe-based real-time Polymerase Chain Reaction (PCR). 12 probes and primers were used for the detection of Aggregatibacter actinomycetemcomitans, Chlamydia pneumoniae, viridans group streptococci, Porphyromonas gingivalis, Fusobacterium nucleatum, Tannarella forsythia, Treponema denticola, Helycobacter pylori, Mycoplasma pneumoniae, Staphylococus aureus,  Prevotella intermedia and Streptococcus mutans. Thus, DNA of four species of bacteria was detected in 10 of the 109 patients studied. The most frequent species was viridans group streptococci (6 patients, 5.5%), followed by Staphylococus aureus (2 patients, 1.8%). Moreover, a patient had DNA of Porphyromonas gingivalis (0.9%); and another patient had DNA of Prevotella intermedia (0.9%). Bacterial DNA was not detected in peripheral blood of any of our patients. In conclusion, DNA of four species of endodontic and periodontal bacteria was detected in thrombotic material of 10 STEMI patients. Bacterial DNA was not detected in the peripheral blood of patients with bacterial DNA in their thrombotic material. Bacteria could be latently present in plaques and might play a role in plaque instability and thrombus formation leading to ACS.

[Endocarditis caused by Staphylococcus lugdunensis. Hospital incidence]. / Endocarditis por Staphylococcus lugdunensis. Incidencia hospitalaria.

BACKGROUND: Staphylococcus lugdenensis is a coagulase negative staphylococcus (CNS) associated with a wide spectrum of infections among which infectious endocarditis may be found and in which it is an aggressive pathogen. METHODS: Since 1993 a systematic search for S. lugdenensis in all the staphylococci isolated in blood cultures and the possibility of endocarditis en all of these was determined. A review of all the cases of endocarditis in the literature was performed. RESULTS: Three cases of endocarditis by S. lugdenensis on the native valve were detected from January 1993 to June 1997. None of the patients presented previous heart disease or risk factors. In all the cases, at least three blood cultures were positive for S. lugdenensis and vegetations were observed by echocardiogram. Despite correct antibiotic treatment, disappearance of fever, negativization of control blood cultures and in the third case, valve replacement, two patients presented heart failure and all died. On review of the literature 31 cases of endocarditis were found with valve replacement and mortality being 55%. It should be indicated that 85% of the patients who survived required surgery. CONCLUSIONS: Endocarditis by S. lugdenensis is a severe infection frequently requiring valve replacement and is associated with a high mortality. Therefore, adequate early identification of the microorganism is necessary distinguishing it from the remaining CNS.

Cancer risk among oil refinery workers. A review of epidemiologic studies.

The possibility that excess cancers result from occupational exposures in oil refineries has generated a great deal of interest. Ecological studies and case-control studies in the general population have suggested a positive association between oil industry activity and cancer rates, with more direct evidence provided by studies of refinery employees. The eight investigations of cancer risks among refinery employees are critically reviewed. The methodological strengths and weaknesses of these studies are evaluated with an emphasis on the likely impact on the results. While the results are markedly inconsistent across studies, there is some suggestion of excess risks for melanoma and for brain, stomach, kidney, and pancreatic cancers. Problems with exposure characterization, latency, and potential confounding factors limit all of the studies that were reviewed.