Immunosenescence, Inflammaging and Resilience: An Evolutionary Perspective of Adaptation in the Light of COVID-19 Pandemic.

The evolution of immunology enabled the study of role of innate and adaptive immunity in systems biology network of immunosenescence and inflammaging. Due to global reduction in birth rates and reduced mortality, in year 2025 there will be about 1.2 billion of people over age of sixty, worldwide. The notion that the real age is not chronological, but the biological one led to the concept of "bioage", defining the biologic reactivity and resilience, including the immune competence of an individual. A competent immune network, systemic and mucosal is intrinsic to resilience and homeostasis of the human holobiont as the unit of evolution. In elderly, the immunosenescence could be associated with higher levels of proinflammatory mediators (such as IL-6), frialty and mortality. Proi-inflammatory state in elderly is denoted as inflammaging, characterized with low-grade (sterile) inflammation, as a physiologic response to life-long antigenic stimuli. When under control, inflammaging could be regarded as an efficient defense mechanism, oposed and regulated by anti-inflammatory pathways and molecules. Immunosensecence. The emerging concepts of "individual immunobiography" and "trained immunity" speak in favour that the immunological experience during the life would shape the ability of each individual to respond to various stimuli, strongly influencing the elements of innate and adaptive immunity, including macrophages and innate lymphoid cells. Older age is one of the main risk factors for the severe clinical picture and adverse outcome of COVID-19 infection, due to immunosenscence and chronic low-grade inflammation (inflammaging), both characterizing the immune reactioin in elderly. The senescent immune system, along with the advanced process of inflammaging is prone to react with uncontrolled activation of innate immune response that leads to cytokine release syndrome, tissue damage and adverse outcome of infection. Further research is aimed to nutritional and pharmacologic (immunomodulatory) interventions to influence the process of bioaging and immunosenscence, and to modulate the reaction of elderly to infection, including the COVID-19.

European confederation of medical mycology expert consult-An ECMM excellence center initiative.

OBJECTIVES: Difficult-to-treat invasive fungal infections require infectious diseases expert consultation to improve treatment outcome and increase survival rates. METHODS: The European Confederation of Medical Mycology (ECMM) intends to provide expert help free of charge by a newly founded ECMM Expert Consultation Service for medical centres around the globe seeking advice when there is no fungal infection consultant available. The expert consult will provide recommendations and broad expertise on difficult-to-treat invasive fungal infections (eg azole-resistant Aspergillus species, Candida auris, mucormycosis) to improve diagnostic and therapeutic management and outcome. RESULTS: The initiative plans global outreach through video conferencing between ECMM Excellence Centers and treating physicians. FungiScope® registries will be used to structure case information and to evaluate the impact of the collegial advice system at regular intervals. Advice will follow recent guidelines, and EQUAL Scores will be used to measure guideline adherence. CONCLUSIONS: Infectious diseases expert consultation should be an integral component of care for patients with difficult-to-treat invasive fungal infections. The ECMM Expert Consult will attend to this matter on a global scale.

Successful separation of xypho-omphalopagus conjoined twins with extrauterine twin-twin transfusion syndrome: a case report.

Conjoined twining is a rare medical phenomenon, with an overall prevalence of 1.47 per 100 000 births. This report describes a successful separation of xypho-omphalopagus conjoined twins complicated by unbalanced blood shunting through the porto-systemic anastomoses within the shared liver parenchyma. Significant extrauterine twin-twin transfusion syndrome caused by unbalanced shunting is an extremely rare, and probably under-recognized, hemodynamic complication in conjoined twins necessitating urgent separation. Progressive deterioration with a poor outcome can be prevented if the condition is recognized in a timely manner.

Epidemiology of Candidemia: Three-Year Results from a Croatian Tertiary Care Hospital.

Invasive candidosis is the most common invasive fungal infection in hospitalized patients and is associated with a high mortality rate. This is the first study from a Croatian tertiary care hospital describing epidemiology, risk factors and species distribution in patients with candidemia. A three-year retrospective observational study, from 2018 to 2020, was performed at the University Hospital Centre Zagreb, Zagreb, Croatia. A total of 160 patients with candidemia (n = 170 isolates) were enrolled. Candidemia incidence increased from 0.47 to 0.69 per 1000 admissions in 2018 and 2020, respectively. Ninety-five patients (58.38%) were in the intensive care unit. The main risk factors for candidemia were central venous catheter (CVC) (84.38%), previous surgical procedure (56.88%) and invasive mechanical ventilation (42.50%). Candida albicans was identified in 43.53% of isolates, followed by C. parapsilosis (31.76%) and C. glabrata (12.36%), C. krusei (5.29%), C. tropicalis (2.35%) and C. lusitaniae (2.35%). The study discovered a shift to non-albicansCandida species, particularly C. parapsilosis, and made it possible to determine the main tasks we should focus on to prevent candidemia in the hospital, these being mainly infection control measures directed towards prevention of catheter-related bloodstream infections, specifically comprising hand hygiene and CVC bundles of care. The potential benefit of fluconazole prophylaxis in certain populations of surgical patients could also be considered.

Characteristics, Risk Factors and Predictors for Candidemia in the Pediatric Intensive Care Unit at the University Hospital Centre Zagreb in Croatia: A 9-Year Retrospective Study.

BACKGROUND: Candidemia is one of the leading causes of bloodstream infections in the pediatric intensive care unit (PICU). The aim of this study was to define characteristics and risk factors for candidemia in the PICU setting and propose a predictive model to identify the patients at risk. METHODS: This was a retrospective matched case-control study in the PICU during a 9-year period. Patients with candidemia were studied and matched with control patients without candidemia. Univariate analysis was performed for potential risk factors and multivariate analysis was conducted to determine the prediction score for candidemia. RESULTS: Forty-two cases of candidemia were matched with 84 control patients. Candida parapsilosis was the most common (71.4%) species. Risk factors independently associated with candidemia were: the use of >2 antibiotics in a maximum period of 4 weeks before the candidemia (odds ratio [OR]: 10.59; 95% confidence interval [CI]: 2.05-54.83), a previous bacterial infection in a maximum period of 4 weeks before the candidemia (OR: 5.56; 95% CI: 1.44-21.5) and the duration of PICU stay of >10 days (OR: 4.22; 95% CI: 1.02-17.41). The proposed predictive scoring system has a sensitivity of 95.24%, specificity of 76.12%, OR 64.0, 95% CI 14.2-288.6, the positive predictive value of 66.67% and the negative predictive value of 96.97%. CONCLUSIONS: Previously reported risk factors for candidemia have been confirmed and some new have been detected. The presented scoring system can help identify patients who would benefit from prophylactic antifungal therapy.

Effect of azithromycin on acute inflammatory lesions and colonic bacterial load in a murine model of experimental colitis.

BACKGROUND: The aim of this study was to investigate the effect of the macrolide antibiotic azithromycin on mucosal changes and colonic bacterial load in a murine model of colitis. METHODS: Colitis was induced in CD1 mice using enema of 0.2% solution of dinitrofluorobenzene, combined with skin sensitization. Four experimental groups of animals (N = 10 per group) were treated with 50 mg/kg/day azithromycin (AZ) or metronidazole (MN) perorally, starting 24 h before (AZ-1, MN-1) or 6 h after (AZ+1, MN+1) induction of colitis and for consecutive 5 days. Additional experimental mice group was treated with 10 mg/kg/day methylprednisolone intraperitoneally after induction of experimental colitis in the same manner (MP). Two control groups consisted of healthy animals (C) that received the challenge enema with phosphate-buffered saline (PBS) and animals with experimental colitis (chall) treated with equivolume of PBS perorally. Clinical score (0-5) and histopathologic score (0-30) were used to assess inflammatory changes, and colon washings were used to determine changes in bacterial load. RESULTS: The anti-inflammatory effect of azithromycin did not differ from the effect of methylprednisolone, when compared with control group with experimental colitis. Metronidazole did not show a significant anti-inflammatory effect. Number of colonic bacteria did not differ significantly between control and experimental groups of animals. CONCLUSIONS: We documented the anti-inflammatory effect of azithromycin in a murine model of acute colitis, suggesting that effects were targeted to oxidative burst and on mucosal/bacterial interface, independent of luminal bacterial load. Further studies should be focused on effect of azithromycin on the role of bacterial biofilm in perpetuation of chronic intestinal inflammation.

Variable Correlation between Bronchoalveolar Lavage Fluid Fungal Load and Serum-(1,3)-ß-d-Glucan in Patients with Pneumocystosis-A Multicenter ECMM Excellence Center Study.

Pneumocystis jirovecii pneumonia is a difficult invasive infection to diagnose. Apart from microscopy of respiratory specimens, two diagnostic tests are increasingly used including real-time quantitative PCR (qPCR) of respiratory specimens, mainly in bronchoalveolar lavage fluids (BAL), and serum ß-1,3-d-glucan (BDG). It is still unclear how these two biomarkers can be used and interpreted in various patient populations. Here we analyzed retrospectively and multicentrically the correlation between BAL qPCR and serum BDG in various patient population, including mainly non-HIV patients. It appeared that a good correlation can be obtained in HIV patients and solid organ transplant recipients but no correlation can be observed in patients with hematologic malignancies, solid cancer, and systemic diseases. This observation reinforces recent data suggesting that BDG is not the best marker of PCP in non-HIV patients, with potential false positives due to other IFI or bacterial infections and false-negatives due to low fungal load and low BDG release.

First Isolation, Antifungal Susceptibility, and Molecular Characterization of Cryptococcus neoformans from the Environment in Croatia.

The purpose of this study was to investigate the presence of Cryptococcus neoformans species complex isolates from environmental sources in Croatia and to determine their molecular types and antifungal susceptibility. Swab samples of tree hollows and bird excreta in the soil beneath trees were collected. Samples included 472 (92.73%) samples obtained from tree hollows and 37 (7.27%) samples from bird excreta. Four C. neoformans species complex isolates were recovered from tree hollow swabs along the Mediterranean coast, while there were no isolates recovered from bird excreta or from the continental area. Three isolates were identified as molecular types VNI and one as VNIV. All tested antifungals showed high in vitro activity against the four isolates. This is the first report proving the presence of C. neoformans species complex in the environment of Croatia. The results of the study suggest a major risk of exposure for inhabitants living along the Croatian coast and that both VNI and VNIV molecular types can be expected in clinical cases of cryptococcosis. Susceptibility to antifungals confirmed that no resistance should be expected in patients with cryptococcosis at the present time.

Informed consent for gastrointestinal endoscopy: a view of endoscopists in Croatia.

BACKGROUND/AIM: There are many differences and deficiencies in the process of informed consent. The aim of this study was to get the view of gastrointestinal endoscopists in Croatia on obtaining patients' consent before endoscopic procedures. METHODS: During the 2004 annual meeting of the Croatian Society of Gastroenterology, endoscopists were asked to answer a questionnaire according to common clinical practice in affiliated institutions. It included questions on endoscopists' experience and education in medical ethics, as well as on the nature and quality of information given to patients and their opinion on proposed measures for improvement of the informed consent process. RESULTS: The questionnaire was distributed to 96 endoscopists attending the meeting and the response rate was 54% (52/96). In only 50% of institutions was the obtained consent written and potential complications of endoscopic procedures are occasionally given to the patient. In the minority of cases the patient is provided with information about alternative diagnostic tests and/or treatment options, and the information about mortality rate was almost never discussed. CONCLUSIONS: In Croatia, the process of informed consent for endoscopy needs improvement and should be regarded against the background of education in medical ethics, regional burden in endoscopic practice and appropriateness of by-laws and local guidelines.

Antimicrobial efficacy of photodynamic therapy, Nd:YAG laser and QMiX solution against Enterococcus faecalis biofilm.

BACKGROUND: Lasers have been recommended in final root canal disinfection protocol, however, there is no clear evidence about their efficacy against bacteria in biofilms. The aim of the study was to evaluate and compare the disinfection effect of antimicrobial photodynamic therapy (aPDT), Nd:YAG laser and QMiX solution against Enterococcus faecalis biofilm. METHODS: The study sample consisted of 65 dentine slices, which were inoculated with E. faecalis and incubated anaerobically for three weeks. The dentine discs were randomly allocated to one of the following experimental groups: aPDT (100 mW, 10 mg/ml phenothiazinium chloride, 1 min), Nd:YAG laser (2 W, 15 Hz, 4×5 s), QMiX solution (1 min). Positive controls did not receive any treatment and negative controls were treated with 5.25% NaOCl. To harvest surviving adherent cells, each dentine sample was transffered to a test tube containing of TSB, serial ten-fold dilutions were made and aliquot of 1 ml was plated onto blood agar plates and incubated for 48 h. Colony forming units grown were counted and transformed into actual counts based on the dilution factor. The remaining viable cells after each protocol were analysed by FISH. RESULTS: The aPDT and the QMiX solution were equally effective, with the reduction rate of E. faecalis CFUs of 98.8% and 99.3% respectively (p=1.107). The Nd:YAG laser caused 96% reduction of E. faecalis (P<0.001). CONCLUSION: The aPDT and the QMiX solution showed similar antibacterial efficacy against old E. faecalis biofilm, followed by Nd:YAG irradiation.

Unusually low prevalence of Mycoplasma genitalium in urine samples from infertile men and healthy controls: a prevalence study.

OBJECTIVE: To detect Mycoplasma genitalium in urine samples of infertile men and men without any signs of infection in order to investigate whether M. genitalium and other genital mycoplasmas (Mycoplasma hominis and Ureaplasma spp) are found more often in urine samples of infertile men than in asymptomatic controls and to determine resistance to macrolides. METHODS: The study included first void urine samples taken from 145 infertile men and 49 men with no symptoms of urethritis. M. genitalium, Chlamydia trachomatis and Neisseria gonorrhoeae were detected by commercial PCR. Trichomonas vaginalis was detected by microscopy and culture. M. hominis and Ureaplasma spp were detected by culture. M. genitalium was detected by in-house conventional and real-time PCR. RESULTS: Two M. genitalium positive samples were found among samples obtained from infertile men. All asymptomatic men were M. genitalium negative. Macrolide resistance was not found in either of the two positive samples. CONCLUSIONS: In comparison with reported data, an unusually low prevalence of M. genitalium was found in infertile men. The reasons for this unexpected result are not known; possibly, local demographic and social characteristics of the population influenced the result. Further studies to investigate M. genitalium in infertile and other groups of patients are needed.

Effect of cyclosporine in a murine model of experimental colitis.

The use of immunosuppressive therapy may be associated with significant toxicity. The aim of this study was to investigate the effect of cyclosporine A (CsA) in murine model of experimental colitis. Experimental colitis was induced in NMRI mice using an enema of 0.2% solution of dinitrofluorobenzene, combined with skin sensitization. After inducing colitis, experimental groups of animals were treated with CsA (1, 3, 5, 10, 25, 50 mg/kg/day) intraperitoneally (i.p.) or intracolonically (i.c.), and control groups were treated with phosphate-buffered saline intraperitoneally or intracolonically, respectively. Colonic inflammatory changes were assessed using a histopathologic score of 0-30, and pooled whole blood samples were processed with monoclonal antibodies for cyclosporine concentration. In addition, two groups of animals with experimental colitis were treated intraperitoneally or intracolonically with 3 mg/kg/day of CsA, and the colons were also taken for immunohistochemistry for CD25. CsA diminished the extent of colitis in groups treated with 3, 5, 10, or 25 mg/kg intraperitoneally or intracolonically, and in groups treated with 1 and 50 mg/kg intracolonically (P < 0.05). The effect of intracolonic application of CsA was not related to whole blood cyclosporine concentrations. In addition, the effect of CsA at 3 mg/kg, applied intraperitoneally or intracolonically was, in part, expressed in decreasing the numbers of CD25+ cells within colonic mucosa/submucosa (P < 0.05). In conclusions, the results of this study indicate the possibility of intracolonic application of cyclosporine in order to widen the therapeutic window for effective, but possibly toxic drug, such as cyclosporine.

Incidence, epidemiology, and characteristics of quinolone-nonsusceptible Streptococcus pneumoniae in Croatia.

Among 585 Streptococcus pneumoniae strains isolated in 22 Croatian hospitals 21 strains (3.6%) were quinolone nonsusceptible. MICs of all quinolones were high for seven strains tested with the same serotype (23F) and mutations in gyrA, parC, and parE. The remaining 14 strains were more heterogeneous and had mutations only in parC and/or parE, and the MICs of quinolones were lower for these strains.