Polyamines and microbiota in bicuspid and tricuspid aortic valve aortopathy.

Polyamines are small aliphatic cationic molecules synthesized via a highly regulated pathway and involved in general molecular and cellular phenomena. Both mammalian cells and microorganisms synthesize polyamines, and both sources may contribute to the presence of polyamines in the circulation. The dominant location for microorganisms within the body is the gut. Accordingly, the gut microbiota probably synthesizes most of the polyamines in the circulation in addition to those produced by the mammalian host cells. Polyamines are mandatory for cellular growth and proliferation. Established evidence suggests that the polyamine spermidine prolongs lifespan and improves cardiovascular health in animal models and humans through both local mechanisms, involving improved cardiomyocyte function, and systemic mechanisms, including increased NO bioavailability and reduced systemic inflammation. Higher levels of polyamines have been detected in non-dilated aorta of patients affected by bicuspid aortic valve congenital malformation, an aortopathy associated with an increased risk for thoracic ascending aorta aneurysm. In this review, we discuss metabolism of polyamines and their potential effects on vascular smooth muscle and endothelial cell function in vascular pathology of the thoracic ascending aorta associated with bicuspid or tricuspid aortic valve.

Hypoxia induces senescence of bone marrow mesenchymal stem cells via altered gut microbiota.

Systemic chronic hypoxia is a feature of many diseases and may influence the communication between bone marrow (BM) and gut microbiota. Here we analyse patients with cyanotic congenital heart disease (CCHD) who are experiencing chronic hypoxia and characterize the association between bone marrow mesenchymal stem cells (BMSCs) and gut microbiome under systemic hypoxia. We observe premature senescence of BMSCs and abnormal D-galactose accumulation in patients with CCHD. The hypoxia that these patients experience results in an altered diversity of gut microbial communities, with a remarkable decrease in the number of Lactobacilli and a noticeable reduction in the amount of enzyme-degraded D-galactose. Replenishing chronic hypoxic rats with Lactobacillus reduced the accumulation of D-galactose and restored the deficient BMSCs. Together, our findings show that chronic hypoxia predisposes BMSCs to premature senescence, which may be due to gut dysbiosis and thus induced D-galactose accumulation.

Preoperative colonization in pediatric cardiac surgery and its impact on postoperative infections.

BACKGROUND: Patients with congenital heart defects are frequently hospitalized before surgery. This exposes them to a high risk for pathogen colonization. There are limited data on colonization prevalence in the pediatric cardiac population, and limited data concerning its potential role in the risk of developing infections after cardiac surgery. AIM: This study aimed to verify the impact of preoperative colonization on postoperative infections in a population of pediatric cardiac surgery patients coming from Italy and developing countries. METHODS: This was a retrospective study conducted in all the patients aged ≤18 years who underwent pediatric open-heart surgery in the year 2015. Clinical data were retrieved from the institutional database for cardiac surgery patients. Data on swab cultures were retrieved from the laboratory database. Swab colonization was tested for association with infection and other outcomes. RESULTS: Among 169 children who performed the screening for pathogen colonization, 50% had at least one positive swab. Italian patients were (P=.001) less likely to be colonized with respect to foreign patients (relative risk 0.17, 95% CI 0.09-0.35). Postoperative infections in colonized patients occurred at a similar rate as in noncolonized patients (relative risk 1.24, 95% CI 0.64-2.39; P=.532). Colonized patients had a preoperative stay (P=.021) longer than noncolonized patients (mean difference 2 days, 95% CI 0.3-3.8 days). CONCLUSION: The results of our study suggest that the impact of preoperative colonization on outcome and postoperative infections may be negligible; larger series are required to clearly define this issue.

Rhodotorula fungemia: Report of two cases in Sfax (Tunisia).

Rhodotorula is emerging as an important cause of nosocomial and opportunistic infections. We present two cases of Rhodotorula mucilaginosa fungemia diagnosed at our hospital during the last decade. The first case was of a term neonate who presented congenital heart disease (interventricular communication) and body dysmorphic disorder. He was admitted for respiratory failure and sepsis. The second case involved in a 33-year-old woman that had Hodgkinien lymphoma associated to tuberculosis. Identification was performed using commercial systems and confirmed by PCR sequencing of internal transcribed spacer, ITS1 and ITS2 regions of rDNA. Antifungal susceptibility tested by sensititre yeast revealed susceptibility to amphotericin B and resistance to fluconazole for the two strains. These cases emphasize the emerging importance of Rhodotorula sp. as a pathogen and it must be considered a potential pathogen in patients with immunosupression and with central venous catheters. Correct identification is mandatory for appropriate management, as Rhodotorula spp. are resistant to antifungal agents, such as fluconazole.

Presence of Aggregatibacter actinomycetemcomitans in saliva and cardiac tissue samples of children with congenital heart disease.

AIM: The purpose of this study was to analyze the presence of Aggregatibacter actinomycetemcomitans in saliva and cardiac tissue samples of children requiring cardiac surgery in Istanbul, Turkey. SUBJECTS AND METHODS: Twenty-five patients (mean age: 6.24 ± 2.93) undergoing surgery for congenital heart defects (CHDs) and an age/gender-matched control group of 25 healthy children were enrolled in the study. Saliva samples were collected from all children; plaque index (PI) and gingival index (GI) were also determined. In CHD group, cardiac tissue samples were received during surgery. All samples were evaluated for the presence of A. actinomycetemcomitans and its highly leukotoxic JP2 clonal strains using polymerase chain reaction. The findings were analyzed by Mann-Whitney U, Chi-square, and Fisher's exact tests. RESULTS: No significant differences were found in PI and GI values between the groups. A. actinomycetemcomitans was not detected in cardiac tissue samples. A. actinomycetemcomitans in saliva was detected in 2 (8%) of the CHD and 5 (20%) of the control children (p > 0.05). A. actinomycetemcomitans JP2 clonal strains were determined from 1 (4%) of the control group while it was not determined from the samples of the CHD group. CONCLUSIONS: Early colonization of A. actinomycetemcomitans in oral cavities could be assessed as a risk marker for periodontal disease. Periodontal pathogens may enter bloodstream through bacteremia; thus, the presence of periodontal pathogens in the oral cavity of children should be assessed as a risk marker for cardiac diseases in older ages.

[Surgical treatment for aortic valve endocarditis combined with bacterial meningitis and vertebral osteomyelitis;report of a case].

A 59-year-old man was referred to our hospital with disturbance of consciousness. Bacterial meningitis was diagnosed by a spinal tap, and penicillin sensitive Streptococcus pneumonia was detected by blood culture. Magnetic resonance imaging revealed a vertebral osteomyelitis. Treatment with antibiotics was started immediately. Four days after admission, congestive heart failure suddenly occurred. Echocardiography showed mobile vegetation on the aortic valve, and severe regurgitation. As acute heart failure could not be controlled, the aortic valve was replaced by ATS 22AP valve on the 7th day after admission. Antibiotic therapy was continued for 8 weeks. The postoperative course was uneventful.

Outcome of aortic valve replacement for active infective endocarditis in patients on chronic hemodialysis.

BACKGROUND: The high risk of morbidity and mortality for patients on hemodialysis who are undergoing cardiac surgery is increased for those with active infective endocarditis (AIE). This retrospective observational single-center study evaluated the impact of chronic hemodialysis on the outcome of aortic valve replacement in patients with aortic AIE. METHODS: Data were retrospectively collected for consecutive patients undergoing aortic valve surgery for AIE diagnosed according to modified Duke criteria between October 1994 and January 2011. Characteristics and outcomes of patients receiving preoperative chronic hemodialysis were analyzed. RESULTS: Aortic valve AIE was present in 992 patients. Forty-five (4.5%) of the aortic valve AIE patients were receiving long-term hemodialysis preoperatively, 19 of whom (42.2%) had diabetes mellitus. Mean logistic EuroSCORE was 64.2% ± 32.2%. Twenty-four preoperative septic emboli were found in 15 patients. Results of microbiologic cultures were positive in 36 patients, with the major causative organisms identified as Staphylococcus aureus (n = 17) and Enterococcus faecalis (n = 10). Isolated aortic valve replacement was performed in 19 patients (42.2%), and 26 patients (57.8%) underwent concomitant procedures. The mean follow-up was 5.3 ± 5.2 years (range, 0.1 to 17.1 years). Postoperative complications occurred in 30 patients (66.7%). Nineteen patients (42.2%) died within 30 days of surgery, which in 8 patients was attributable to a cardiac cause. CONCLUSIONS: In patients receiving chronic hemodialysis who undergo aortic valve replacement for acute AIE, postoperative mortality is high, especially in patients undergoing aortic root replacement or culture-negative AIE.

Pregnancy and postpartum infective endocarditis: a systematic review.

The objective of this review was to describe the clinical characteristics, risk factors, and outcomes of infective endocarditis (IE) in pregnancy and the postpartum period. We conducted a systematic review of Ovid MEDLINE, Ovid Embase, Web of Science, and Scopus from January 1, 1988, through October 31, 2012. Included studies reported on women who met the modified Duke criteria for the diagnosis of IE and were pregnant or postpartum. We included 72 studies that described 90 cases of peripartum IE, mostly affecting native valves (92%). Risk factors associated with IE included intravenous drug use (14%), congenital heart disease (12%), and rheumatic heart disease (12%). The most common pathogens were streptococcal (43%) and staphylococcal (26%) species. Septic pulmonary, central, and other systemic emboli were common complications. Of the 51 pregnancies, there were 41 (80%) deliveries with survival to discharge, 7 (14%) fetal deaths, 1 (2%) medical termination of pregnancy, and 2 (4%) with unknown status. Maternal mortality was 11%. Infective endocarditis is a rare, life-threatening infection in pregnancy. Risk factors are changing with a marked decrease in rheumatic heart disease and an increase in intravenous drug use. The cases reported in the literature were commonly due to streptococcal organisms, involved the right-sided valves, and were associated with intravenous drug use.

Report from the Society of Thoracic Surgeons National Database Workforce: clarifying the definition of operative mortality.

Several distinct definitions of postoperative death have been used in various quality reporting programs. Some have defined postoperative mortality as the occurrence of death after a surgical procedure when the patient dies while still in the hospital, while others have considered all deaths occurring within a predetermined, standardized time interval after surgery to be postoperative mortality. While mortality data are still collected and reported using both these individual definitions, the Society of Thoracic Surgeons (STS) believes that either approach alone may be inadequate. Accordingly, the STS prefers a more encompassing metric, Operative Mortality. Operative Mortality is defined in all STS databases as (1) all deaths, regardless of cause, occurring during the hospitalization in which the operation was performed, even if after 30 days (including patients transferred to other acute care facilities); and (2) all deaths, regardless of cause, occurring after discharge from the hospital, but before the end of the 30th postoperative day. This article provides clarification for some uncommon but important scenarios in which the correct application of this definition may be challenging.

Probiotic administration in congenital heart disease: a pilot study.

OBJECTIVE: To investigate the impact of probiotic Bifidobacterium longum ssp. infantis on the fecal microbiota and plasma cytokines in neonates with congenital heart disease. STUDY DESIGN: Sixteen infants with congenital heart disease were randomly assigned to receive either B. infantis (4.2 × 10(9) colony-forming units two times daily) or placebo for 8 weeks. Stool specimens from enrolled infants and from six term infants without heart disease were analyzed for microbial composition. Plasma cytokines were analyzed weekly in the infants with heart disease. RESULTS: Healthy control infants had increased total bacteria, total Bacteroidetes and total bifidobacteria compared to the infants with heart disease, but there were no significant differences between the placebo and probiotic groups. Plasma interleukin (IL)10, interferon (IFN)γ and IL1ß levels were transiently higher in the probiotic group. CONCLUSION: Congenital heart disease in infants is associated with dysbiosis. Probiotic B. infantis did not significantly alter the fecal microbiota. Alterations in plasma cytokines were found to be inconsistent.

Deciphering genomic virulence traits of a Staphylococcus epidermidis strain causing native-valve endocarditis.

We applied real-time genome sequencing to a Staphylococcus epidermidis strain that caused native-aortic-valve endocarditis in a 26-year-old patient. The 2.5-Mb genome from strain CSUR P278 exhibited a unique sequence type among S. epidermidis strains and contained 32 genes previously considered virulence genes in this species.

Comparison of six generic vancomycin products for treatment of methicillin-resistant Staphylococcus aureus experimental endocarditis in rabbits.

Concerns have recently emerged about the potency and the quality of generic vancomycin (VAN) products approved for use in humans, based on experiments in a neutropenic mouse thigh infection model. However, other animal models may be more appropriate to decipher the bactericidal activities of VAN generics in vivo and to predict their efficacy in humans. We aimed to compare the bactericidal activities of six generic VAN products currently used in France (Mylan and Sandoz), Spain (Hospira), Switzerland (Teva), and the United States (Akorn-Strides and American Pharmaceutical Products [APP]) in a rabbit model of aortic valve endocarditis induced by 8 × 10(7) CFU of methicillin-resistant Staphylococcus aureus (MRSA) strain COL (VAN MIC, 1.5 µg/ml). In vitro, there were no significant differences in the time-kill curve studies performed with the six generic VAN products. Ten rabbits in each group were treated with intravenous (i.v.) VAN, 60 mg/kg of body weight twice a day (b.i.d.) for 4 days. Mean peak serum VAN levels, measured 45 min after the last injection, ranged from 35.5 (APP) to 45.9 µg/ml (Teva). Mean trough serum VAN levels, measured 12 h after the last injection, ranged from 2.3 (Hospira) to 9.2 (APP) µg/ml. All generic VAN products were superior to controls (no treatment) in terms of residual organisms in vegetations (P < 0.02 for each comparison) and in the spleen (P < 0.005 for each comparison). Pairwise comparisons of generic VAN products found no significant differences. In conclusion, a stringent MRSA endocarditis model found no significant differences in the bactericidal activities of six generic VAN products currently used in Europe and America.

Caries-, Candida- and Candida antigen/antibody frequency in children after heart transplantation and children with congenital heart disease.

The aim of this study was to determine the incidence of oral/intestinal Candida colonization and Candida-antigen/antibody in immunosuppressed children after HTx (group III, n = 31), in children with CHD (group II, n = 24) and in children with healthy hearts (comparison group, group I, n = 23) aged 2-16 yr according to their dental status between 2004 and 2007. Candida species in saliva, dental plaque, carious lesions and stool were detected with Sabouraud-/CHROMagar and Auxacolor system. Candida-specific-antigen/antibody assays were used for serological diagnosis. Dental status was determined on the basis of the DMF/dmf(T/t)-index. We found significant group differences in fecal Candida colonization (p = 0.027). In relation to dental status, oral Candida colonization increased within group III from 28.5% [DMF/dmf(T/t) = 0] to 66.7% [DMF/dmf(T/t) > or = 1] up to 100.0% [D/d(T/t) > or = 1], similar in groups I and II. Candida-mannan-antigen was determined to be positive in 16.1% (HTx), 5.5% (CHD) and 13.0% (comparison group). We show correlation between oral Candida colonization and (carious) dental status. We assume that high oral Candida and their descending/resorption through the gastrointestinal tract may lead to serologic Candida accumulation or rather candidiasis. Therefore, healthy oral cavity (especially before/after HTx) is an important precondition to prevent Candida infections.