Bacterial invasive infections in a neonatal intensive care unit: a 13 years microbiological report from an Italian tertiary care centre.

INTRODUCTION: To evaluate the aetiology of neonatal invasive diseases (positive cultures from blood or cerebrospinal fluid, CSF) due to bacteria other than coagulase-negative staphylococci in a large tertiary care centre and compare with results of surveillance cultures. METHODS: Retrospective analysis of microbiological data of children admitted in neonatal intensive care unit (NICU) of a large tertiary care centre from 2005 to 2018. RESULTS: 230 bacterial strains, 223 from blood and 7 from CSF, respectively, were detected as cause of invasive infections, while 152 were detected in surveillance cultures. Methicillin-susceptible Staphylococcus aureus (MSSA) was the most frequently isolated pathogen both in invasive infections (18%) and colonizations (23%) followed by Escherichia coli (16% on invasive disease and 20% of colonizations). Other common bacteria include Enterococcus faecalis and Streptococcus agalactiae for invasive disease and methicillin-resistant Staphylococcus aureus in colonizations. Invasive infection was due to a pathogen detected in surveillance cultures in 33% of cases. In more than 50% of invasive diseases the identified pathogen was not present in surveillance cultures. CONCLUSIONS: The high percentage of invasive infections due to bacteria not previously identified in surveillance cultures raises doubts about the efficiency of this procedure and highlights the need to search for alternative infection sources. This finding and the high prevalence of invasive infections due to nosocomial pathogens such as Staphylococcus aureus could be the result of horizontal transmission between patients through the hands of health care professionals, emphasizing once again the importance of applying stringent hand hygiene procedures and isolation standards.

Bloodstream infections in patients living with HIV in the modern cART era.

Retrospective multicentre study aiming at analysing the etiology, characteristics and outcome of bloodstream infections (BSI) in people living with HIV (PLWHIV) in an era of modern antiretroviral therapy. Between 2008 and 2015, 79 PLWHIV had at least 1 BSI, for a total of 119 pathogens isolated. Patients were mainly male (72.1%), previous intravenous drug users (55.7%), co-infected with HCV or HBV (58.2%) and in CDC stage C (60.8%). Gram-positive (G+) pathogens caused 44.5% of BSI, followed by Gram-negative (G-), 40.3%, fungi, 10.9%, and mycobacteria, 4.2%. Candida spp. and coagulase-negative staphylococci were the most frequent pathogens found in nosocomial BSI (17% each), while E.coli was prevalent in community-acquired BSI (25%). At the last available follow-up, (mean 3.2 ± 2.7 years) the overall crude mortality was 40.5%. Factors associated with mortality in the final multivariate analysis were older age, (p = 0.02; HR 3.8, 95%CI 1.2-11.7) CDC stage C (p = 0.02; HR 3.3, 95%CI 1.2-9.1), malignancies, (p = 0.004; HR 3.2, 95%CI 1.4-7.0) and end stage liver disease (p = 0.006; HR 3.4, 95%CI 1.4-8.0). In conclusion, the study found high mortality following BSI in PLWHIV. Older age, neoplastic comorbidities, end stage liver disease and advanced HIV stage were the main factors correlated to mortality.

Lower sensitivity of serum (1,3)-ß-d-glucan for the diagnosis of candidaemia due to Candida parapsilosis.

The aim of this study was to evaluate the sensitivity and the levels of 1,3-ß-d-glucan (BDG) among patients with candidaemia due to different Candida species. Retrospective study of all patients who had a single-species candidaemia and BDG testing performed within 48 h from the onset of candidaemia during 2009-2015 was performed. Factors influencing the sensitivity of BDG, including the presence of a central venous catheter, antifungal therapy and Candida species, were analysed in univariate and multivariate models. In all, 107 patients with the following Candida distribution were included: 46 (43%) Candida albicans, 37 (35%) Candida parapsilosis, and 24 (22%) other species. BDG sensitivity and levels were the highest in C. albicans candidaemia and lowest for C. parapsilosis (respectively, 72% and 410 pg/mL for C. albicans, 41% and 39 pg/mL for C. parapsilosis, and 63% and 149 pg/mL for other species; p 0.015 and p 0.003). In multivariate analysis, Candida species (parapsilosis versus others) was the only factor influencing the sensitivity of BDG (OR 0.3, 95% CI 0.1-0.7, p 0.006). The sensitivity of BDG in candidaemia seems highly dependent on the fungal species, with the lowest being for C. parapsilosis.

Initial serum (1,3)-ß-D-glucan as a predictor of mortality in proven candidaemia: findings from a retrospective study in two teaching hospitals in Italy and Brazil.

A retrospective study was conducted to assess the role of initial serum (1,3)-ß-d-glucan (BDG) values in predicting mortality in proven candidaemia. The study was conducted in two large teaching hospitals in Italy and Brazil. From January 2009 to June 2014, all patients with proven candidaemia who underwent a BDG test within 96 hours before or after the first positive blood culture were included in the study. The primary end point was 28-day mortality, with the role of initial BDG being assessed by univariate and multivariate analyses. A total of 104 patients met the inclusion criteria. Overall, the crude 28-day mortality was 30% (31/104). In the final multivariate model, an initial BDG of >287 pg/mL (odds ratio (OR) 4.40, 95% confidence interval (CI) 1.56-12.39, p 0.005), haemodialysis (OR 4.33, 95% CI 1.24-15.17, p 0.022) and a Pitt score of ≥ 2 (OR 4.10, 95% CI 1.24-13.54, p 0.021) were significant predictors of 28-day mortality. The >287 pg/mL cutoff predicted 28-day mortality with 65% sensitivity and 70% specificity. Centre of enrolment (p for interaction 0.012), haemodialysis (p for interaction 0.062) and timing of BDG test of more than 24 hours before or after the positive culture (p for interaction 0.143) appeared to interact with BDG's ability to predict mortality. Although not statistically significant, the last two of these interactions might partially explain why BDG's ability to predict mortality was present only in the Italian cohort.

Risk factors and mortality of healthcare-associated and community-acquired Staphylococcus aureus bacteraemia.

Staphylococcus aureus bacteraemia (SAB) is a leading cause of mortality and morbidity in both nosocomial and community settings. The objective of the study is to explore epidemiological characteristics and predisposing risk factors associated with healthcare-associated (HCA) and community-acquired (CA) SAB, and to evaluate any differences in mortality and efficacy of initial antimicrobial therapy on treatment outcome. We conducted a two-part analysis. First, a triple case-control study in which groups of HCA SAB with onset ≥ 48 h after hospital admission (HCA ≥ 48 h), HCA SAB with onset <48 h of hospital admission (HCA <48 h), and CA SAB were compared with controls. Second, a cohort study including all patients with SAB was performed to identify factors associated with in-hospital mortality. SAB was diagnosed in 165 patients over the study period (January 2007 to December 2007). Five variables were independently associated with HCA ≥ 48 h SAB: presence of central venous catheter, solid tumour, chronic renal failure, previous hospitalization and previous antibiotic therapy. Significant risk factors for HCA <48 h SAB were: Charlson Comorbidity Index ≥ 3, previous hospitalization, living in long-term care facilities and corticosteroid therapy. Factors independently associated with CA SAB were: diabetes mellitus, HIV infection and chronic live disease. Patients with HCA <48 h SAB were significantly more likely to receive initial inadequate antimicrobial treatment than patients with CA or HCA ≥ 48 h SAB (44.8% versus 33.3% and 31.5%, respectively). Logistic-regression analysis identified three variables as independent predictors of mortality: presentation with septic shock, infection with methicillin-resistant S. aureus, and initial inadequate antimicrobial treatment. More than half of patients with SAB have MRSA strains and presentation with septic shock, and inappropriate empirical therapy was associated with increased mortality.