ABSTRACT
BACKGROUND: Infective endocarditis (IE) is still a significant cause of mortality in European hospitals, despite of the fact, that large nationwide studies were performed in last twenty years and pathogens are well known. The aim of the study was to assess risk factors, mortality, etiology and proportion of elderly patients within a longitudinal nation wide survey of infectious endocarditis in Slovakia. PATIENTS AND METHODS: Etiology, risk factors and outcome of 1003 cases of infective endocarditis (IE) in Slovakia over the last 33 years have been assessed. RESULTS: The majority of IE were caused by Staphylococci (28.3%), 15.6% were due to Viridans streptococci, 10% due to Enterococci, 8.2% by gram-negative bacteria, Acinetobacter baumannii and Pseudomonas aeruginosa, 3.7% by other organisms and 31.0% of all cases were culture negative. The following risk factors were recorded: age > 65 (36.8%), rheumatic fever (15.3%), dental surgery (8.7%), previous non-cardiological surgery (8.2 %), neoplasia (8.1%), diabetes (7.8%), any endoscopy (8.5%) and dialysis (4.6%). All patients were treated with antimicrobials, 507 (51%) also with surgery. Survival rate at day 60 after diagnosis was 88.1% (n=883). Only age >65 (34.3% vs. 49.5%, p=0.045) and persistent bacteremia (with three or more positive blood cultures 15.7% vs. 34.5%, p=0,001) were significantly associated with higher attributable mortality. Concerning risk factors, etiology and therapeutic strategies, rheumatic fever and neoplasia showed decrease in tendency. Dental surgery and tonsillitis were less frequent as well (26.7% vs. 2%, p<0,001 and 16% vs. 1%, p<0.001). There was a significant shift in etiology after 1997: culture-negative endocarditis was surprisingly more frequently observed in the 2007-2017 period than before and represented 10.7% of all cases in 1984-1990 in comparison to 25.1-25.6% in 2007-2010 and 2011-2017. Staphylococci decreased from 48% to 29.6% (2007-2017), but are still major pathogens. Persistent bacteremia (3 or more positive blood cultures 5.3% vs. 24.7%, p<0,001) was less commonly observed within the 1st period (1984-1990) in comparison to 2007-2010. More patients in the 1st period (1984-1990) had embolization complications of IE than in the fifth and sixth period (2007-2017) (76 vs. 16.3% p<0.001). CNS embolization decreased from 14% to less than 5% (p<0.003). Attributable mortality was lower too (26.7% vs. 9.5%, p<0.001) because of increased proportion of cardiac surgery in the treatment of IE in 2007-2017 in comparison to 1984-1990. CONCLUSIONS: Study has showed significant shifts in etiology, risk factors and complications over the observed time periods in Slovakia.
ABSTRACT
BACKGROUND: The main mechanisms causing high-level resistance to fluoroquinolones (FQ) are encoded chromosomally; that includes mutations in genes coding DNA-gyrase, but overexpression of efflux pumps contributes to increased minimum inhibitory concentration (MIC) of FQ as well. However, genes responsible for FQ-resistance may be harboured in transferable/conjugative plasmids. For some time, there was an assumption that resistance to FQ cannot be transferable in conjugation due to their synthetic origin, until 1998, when plasmid-mediated resistance transmission in Klebsiella pneumoniae was proved. We aimed to detect the occurrence of transferable FQ-resistance among Gram- negative bacteria isolated from patients in Czech and Slovak hospitals. METHODS: In this study, we tested 236 clinical isolates of Gram-negative bacteria for transferable resistance. Among relevant isolates we performed PCR detection of transferable fluoroquinolone genes (qnr). RESULTS: We have observed transfer of determinants of cephalosporin-resistance, aminoglycoside resistance as well as FQ-resistance (in 10 cases; 4.24%) not only intra-species but inter-species too. The presence of qnr gene was detected in two isolates of forty tested (5%). We have also observed that determinants of cephalosporin-resistance and aminoglycoside-resistance were linked to those of FQ-resistance and were transferred en block in conjugation. CONCLUSION: We have proved that resistance to fluoroquinolones can be transferred horizontally via conjugation among Gram-negative bacteria of different species and is associated with resistance to other antibiotics.
