Application of the Weighted-Incidence Syndromic Combination Antibiogram (WISCA) to guide the empiric antibiotic treatment of febrile neutropenia in oncological paediatric patients: experience from two paediatric hospitals in Northern Italy.

BACKGROUND: Guidelines about febrile neutropenia in paediatric patients are not homogeneous; the best empiric treatment of this condition should be driven by local epidemiology. The Weighted-Incidence Syndromic Combination Antibiogram (WISCA) addresses the need for disease-specific local susceptibility evidence that could guide empiric antibiotic prescriptions based on outcome estimates of treatment regimens obtained as a weighted average of pathogen susceptibilities. This study developed a WISCA model to inform empirical antibiotic regimen selection for febrile neutropenia (FN) episodes in onco-haematological paediatric patients treated at two Italian paediatric tertiary centres. METHODS: We included blood cultures from patients with a bloodstream infection and neutropenia admitted to the Paediatric Haematology-Oncology wards in Padua and Genoa Hospitals from 2016 to 2021. WISCAs were developed by estimating the coverage of 20 antibiotics as monotherapy and of 21 combined regimens with a Bayesian probability distribution. RESULTS: We collected 350 blood cultures, including 196 g-negative and 154 g-positive bacteria. Considering the most used antibiotic combinations, such as piperacillin-tazobactam plus amikacin, the median coverage for the pool of bacteria collected in the study was 78%. When adding a glycopeptide, the median coverage increased to 89%, while the replacement of piperacillin-tazobactam with meropenem did not provide benefits. The developed WISCAs showed that no monotherapy offered an adequate coverage rate for the identified pathogens. CONCLUSIONS: The application of WISCA offers the possibility of maximizing the clinical utility of microbiological surveillance data derived from large hospitals to inform the choice of the best empiric treatment while contributing to spare broad-spectrum antibiotics.

Fungal Ecology in a Tertiary Neonatal Intensive Care Unit after 16 Years of Routine Fluconazole Prophylaxis: No Emergence of Native Fluconazole-Resistant Strains.

OBJECTIVE: We analyzed the fungal ecology of a neonatal intensive care unit (NICU) over a period of 20 consecutive years following the introduction of routine fluconazole prophylaxis for all very low birth weight (VLBW; <1,500 g at birth) preterm babies. The aim was to detect the possible appearance of any ecological shifts toward the emergence of native fluconazole-resistant (NFR) fungal species. STUDY DESIGN: This was a retrospective analysis of clinical and microbiological data of VLBW preterm neonates admitted to a large tertiary NICU in Italy from 1997 to 2016 and surviving more than 3 days. Colonization and infection incidence rates, both for fluconazole-sensitive Candida spp and NFR Candida spp, were calculated for each year. We compared the first 4-year period without prophylaxis (1997-2000) with the last 16-year period with use of routine fluconazole prophylaxis (2000-2016). RESULTS: Overall, the incidence of fungal colonization significantly decreased after the introduction of prophylaxis (from 43.4% to 16.5%) as well as the systemic fungal infection incidence (from 16% to 3.7%). The proportion of colonization and infection by NFR Candida spp, on the other hand, did not increase, remaining stable throughout the 16 years of exposure to fluconazole. During the prophylaxis period, 42 of 1,172 VLBW neonates were colonized by NFR species (3.6%), and of them 11 developed a systemic infection (0.9%). During the preprophylaxis period, colonization by these particular species affected 11 of 285 VLBW neonates (3.8%), and a systemic infection involved 4 neonates (1.4%). CONCLUSION: Fluconazole prophylaxis is effective in decreasing Candida colonization and systemic infections in preterm neonates in NICU and did not cause emergence or shifts toward NFR Candida spp over a 16-year surveillance period.

Antibiotic susceptibility of Gram-negatives isolated from bacteremia in children with cancer. Implications for empirical therapy of febrile neutropenia.

BACKGROUND: Monotherapy is recommended as the first choice for initial empirical therapy of febrile neutropenia, but local epidemiological and antibiotic susceptibility data are now considered pivotal to design a correct management strategy. AIM: To evaluate the proportion of Gram-negative rods isolated in bloodstream infections in children with cancer resistant to antibiotics recommended for this indication. MATERIALS & METHODS: The in vitro susceptibility to ceftazidime, piperacillin-tazobactam, meropenem and amikacin of Gram-negatives isolated in bacteremic episodes in children with cancer followed at the Istituto "Giannina Gaslini", Genoa, Italy in the period of 2001-2013 was retrospectively analyzed using the definitions recommended by EUCAST in 2014. Data were analyzed for any single drug and to the combination of amikacin with each ß-lactam. The combination was considered effective in absence of concomitant resistance to both drugs, and not evaluated by means of in vitro analysis of antibiotic combinations (e.g., checkerboard). RESULTS: A total of 263 strains were evaluated: 27% were resistant to piperacillin-tazobactam, 23% to ceftazidime, 12% to meropenem and 13% to amikacin. Concomitant resistance to ß-lactam and amikacin was detected in 6% of strains for piperacillin-tazobactam, 5% for ceftazidime and 5% for meropenem. During the study period there was a nonsignificant increase in the proportions of strains resistant to ß-lactams indicated for monotherapy, and also increase in the resistance to combined therapies. CONCLUSION: in an era of increasing resistance to antibiotics guideline-recommended monotherapy could be not appropriate for initial empirical therapy of febrile neutropenia. Strict local survey on etiology and antibiotic susceptibility is mandatory for a correct management of this complication in cancer patients.

Susceptibility to antibiotics of aerobic bacteria isolated from community acquired secondary peritonitis in children: therapeutic guidelines might not always fit with and everyday experience.

Appendicitis is a frequent clinical condition in normal children that may be complicated by community-acquired secondary peritonitis (CASP). We evaluated the potential efficacy of different drugs for initial treatment of this condition, as recommended by recent Consensus Conference and Guidelines for paediatric patients. Susceptibility to ampicillin-sulbactam, ertapenem, gentamycin, piperacillin, piperacillin-tazobactam, vancomycin, and teicoplanin was evaluated according to EUCST 2012 recommendations in aerobic bacteria isolated from peritoneal fluid in CASP diagnosed from 2005 to 2011 at 'Istituto Giannina Gaslini', Genoa, Italy. A total of 114 strains were analysed: 83 E. coli, 15 P. aeruginosa, 6 Enterococci, and 10 other Gram-negatives. Resistance to ampicillin-sulbactam was detected in 37% of strains, while ertapenem showed a potential resistance of 13% (all P. aeruginosa strains). However, the combination of these drugs with gentamicin would have been increased the efficacy of the treatment to 99 and 100%, respectively. Resistance to piperacillin-tazobactam was 3%, while no strain was resistant to meropenem. Our data suggest that monotherapy with ampicillin-sulbactam or ertapenem for community-acquired secondary peritonitis would present a non-negligible rate of failure, but the addition of gentamycin to these drugs could reset to zero this risk. On the contrary, monotherapy with piperacillin-tazobactam or meropenem is highly effective.

Rescue therapy of difficult-to-treat indwelling central venous catheter-related bacteremias in cancer patients: a review for practical purposes.

Device-related bacteremia is the most frequent complication in patients with indwelling central venous catheter. Guidelines recommend treatment based on epidemiology and antimicrobial susceptibility tests, but catheter removal is advocated in the presence of particular clinical conditions or pathogen isolations. Anti-infective drugs might become less effective in the presence of pathogens with increases in minimal inhibitory concentrations or slime production, and sometimes catheter removal is not feasible, for example, in patients with limited vascular sites or in the presence of life-threatening clinical conditions. Catheter lock with anti-infective drugs (antibacterials or antifungals) or other substances with anti-infective properties (e.g., taurolidine, 70% ethanol, 2M HCl) might represent a possible rescue treatment in the presence of difficult-to-treat infections and/or when the device cannot be removed. In the present review, the authors summarize these possible therapeutic options. The aim of the report is not to perform a systematic review of the literature, but to give an 'easy to read' text for everyday practice.