Prevalence and mortality of ceftazidime/avibactam-resistant KPC-producing Klebsiella pneumoniae bloodstream infections (2018-2022).

INTRODUCTION: Ceftazidime/avibactam-resistance in Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is a topic of great interest for epidemiological, diagnostic, and therapeutical reasons. However, data on its prevalence and burden on mortality in patients with bloodstream infection (BSI) are lacking. This study was aimed at identifying risk factors for mortality in patients suffering from ceftazidime/avibactam-resistant KPC-Kp BSI. METHODS: An observational retrospective study (January 2018-December 2022) was conducted at a tertiary hospital including all consecutive hospitalized adult patients with a ceftazidime/avibactam-resistant KPC-Kp BSI. Data on baseline clinical features, management, and admission outcomes were analyzed. RESULTS: Over the study period, among all the KPC-Kp BSI events recorded, 38 (10.5%) were caused by ceftazidime/avibactam-resistant KPC-Kp strains, 37 events being finally included. The ceftazidime/avibactam-resistant KPC-Kp strains revealed susceptibility restoration to at least one carbapenem in more than 60% of cases. In-hospital and 30-day all-cause mortality rates were 22% and 16.2%, respectively. Non-survivors suffered from more baseline comorbidities and experienced a more severe ceftazidime/avibactam-resistant KPC-Kp BSI presentation (i.e., both the Pitt Bacteremia and INCREMENT-CPE scores were significantly higher). Presenting with a higher Charlson Comorbidity Index, chronic kidney disease-KDIGO stage 3A or worse-having recently gone through renal replacement therapy, having suffered from an acute kidney injury following the ceftazidime/avibactam-resistant KPC-Kp BSI, and being admitted for cardiac surgery were the strongest predictors of mortality. CONCLUSION: Ceftazidime/avibactam resistance in KPC-Kp BSI easily emerged in our highly KPC-Kp endemic area with remarkable mortality rates. Our findings might provide physicians possibly actionable information when managing patients with a ceftazidime/avibactam-resistant KPC-Kp BSI.

Bloodstream Infections by Pantoea Species: Clinical and Microbiological Findings from a Retrospective Study, Italy, 2018-2023.

(1) Background: The widespread use of MALDI-TOF coupled to mass spectrometry has improved diagnostic accuracy by identifying uncommon bacteria. Among Enterobacterales, Pantoea species have been seen to be implicated in several human infections, but their clinical and microbiological framework is currently based on a few anecdotal reports. (2) Methods: We conducted this five-year (2018-2023) single-center study aimed at investigating the prevalence and clinical and microbiological findings of Pantoea species bloodstream infections. (3) Results: Among the 4996 bloodstream infection Gram-negative isolates collected during the study period, Pantoea species accounted for 0.4% (n = 19) of isolates from 19 different patients, 5 of them being pediatric cases. Among Pantoea species isolates, P. agglomerans was the most frequently detected (45%; n = 9) followed by P. eucrina (30%; n = 6) and P. septica (15%; n = 3). Malignancy (35.7%) in adults and malignancy (40%) and cerebrovascular disease following meconium aspiration (40%) in pediatric patients as comorbidities and shivering and/or fever following parenteral infusion (36.8%) as a symptom/sign of Pantoea species bloodstream infection onset were the most frequently observed clinical features. Among adults, primary bloodstream infection was the most frequent (50%), whereas among pediatric patients, the most commonly identified sources of infection were catheter-related (40%) and the respiratory tract (40%). Overall, Pantoea species bloodstream infection isolates displayed high susceptibility to all the antibiotics except for ampicillin (63.2%), fosfomycin (73.7%), and piperacillin/tazobactam (84.2%). Targeted antibiotic treatment was prescribed as monotherapy for adults (71.4%) and combination therapy for pediatric patients (60%). The most prescribed antibiotic regimens were piperacillin/tazobactam (21.4%) in adults and meropenem- (40%) and aminoglycoside-containing (40%) antibiotics in pediatric patients. The overall 28-day all-cause mortality rate was 5.3% (n = 1). (4) Conclusions: The prevalence and 28-day mortality rate of Pantoea species bloodstream infections were low. The prescription of targeted therapy including broad-spectrum antibiotics could indicate an underestimation of the specific involvement of the Pantoea species in the onset of the disease, warranting further studies defining their pathogenic potential.

Anaerobic bloodstream infections in Italy (ITANAEROBY): A 5-year retrospective nationwide survey.

INTRODUCTION: A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. MATERIAL AND METHODS: We conducted a retrospective study on 17 Italian hospitals (2016-2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. RESULTS: A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp., Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). CONCLUSIONS: Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug.

Trueperella bernardiae bloodstream infection following onco-gynaecologic surgery and literature review.

Trueperella bernardiae is a Gram-positive commensal bacillus of the human skin and oropharynx. It is known as an opportunistic human pathogen causing surgical wound, skin, and soft tissue, osteoarticular, and bloodstream infections (BSIs) with severe complications. We report a case of surgical wound related T. bernardiae BSI following onco-gynaecologic surgery together with a comprehensive literature review of T. bernardiae infections to alert clinicians about this emerging pathogen.

Severity of RSV infection in Southern European elderly patients during two consecutive winter seasons (2017-2018).

In Europe, the respiratory syncytial virus (RSV) surveillance system is very heterogeneous and there is growing evidence of the importance of RSV infections resulting in hospitalization of elderly patients. The aim of this study was to assess the severity of RSV infection in the elderly living in the aged Southern European countries. We conducted a retrospective study of elderly patients ( ≥65-year old) admitted for laboratory-confirmed RSV infection in three tertiary hospitals in Portugal, Italy, and Cyprus over two consecutive winter seasons (2017-2018). Uni-multivariable analyses were carried out to evaluate the effect of clinical variables on radiologically confirmed pneumonia, use of noninvasive ventilation (NIV), and in-hospital death (IHD). A total of 166 elderly patients were included. Pneumonia was evident in 29.5%. NIV was implemented in 16.3%, length of stay was 11.8 ± 12.2 days, and IHD occurred in 12.1%. Multivariable analyses revealed that the risk of pneumonia was higher in patients with chronic kidney disease (CKD) (odds ratio [OR]: 2.57; 95% confidence interval [CI]: 1.12-5.91); the use of NIV was higher in patients with obstructive sleep apnea or obesity hypoventilation syndrome (OSA or OHS) (OR: 5.38; 95% CI: 1.67-17.35) and CKD (OR: 2.52; 95% CI: 1.01-6.23); the risk of IHD was higher in males (OR: 3.30; 95% CI: 1.07-10.10) and in patients with solid neoplasm (OR: 9.06; 95% CI: 2.44-33.54) and OSA or OHS (OR: 8.39; 95% CI: 2.14-32.89). Knowledge of factors associated with RSV infection severity may aid clinicians to set priorities and reduce disease burden. Development of effective antiviral treatment and vaccine against RSV is highly desirable.

Renal Allograft Biopsies with Polyomavirus BK Nephropathy: Turin Transplant Center, 2015-19.

BACKGROUND: In kidney transplant patients, polyomavirus-associated nephropathy (PVAN) represents a serious complication; the key factor for the development of PVAN is immunosuppression level and modulation of anti-rejection treatment represents the first line of intervention. Allograft biopsy and histology remain the criterion standard for diagnosing PVAN. METHODS: All consecutive renal biopsies with the diagnosis of PVAN carried out at the University Hospital City of Health and Science of Turin over a five-years period were studied. Renal allograft biopsy was performed due to renal function alterations associated to medium-high polyomavirus BK (BKV)-DNA levels on plasma specimen. RESULTS: A total of 21 patients underwent a first biopsy to diagnose a possible BKV nephropathy, in 18, a second biopsy was made, in eight, a third biopsy, and finally, three underwent the fourth renal biopsy; following the results of each biopsies, immunosuppressant agents dosages were modified in order to reduce the effect of PVAN. CONCLUSIONS: In this study, the clinical and histological features of 21 kidney transplant recipients with BKV reactivation and development of PVAN are described. To date, the only treatment for PVAN consists in the reduction of immunosuppressive agents, constantly monitoring viral load.

Kinetics of cytomegalovirus and Epstein-Barr virus DNA in whole blood and plasma of kidney transplant recipients: Implications on management strategies.

This retrospective multicenter cohort study investigated the kinetics (ascending and descending phases) of cytomegalovirus (CMV) and Epstein-Barr virus (EBV)-DNA in whole blood (WB) and plasma samples collected from adult kidney transplant (KT) recipients. CMV-DNA kinetics according to antiviral therapy were investigated. Three hundred twenty-eight paired samples from 42 episodes of CMV infection and 157 paired samples from 26 episodes of EBV infection were analyzed by a single commercial molecular method approved by regulatory agencies for both matrices. CMV-DNAemia followed different kinetics in WB and plasma. In the descending phase of infection, a slower decay of viral load and a higher percentage of CMV-DNA positive samples were observed in plasma versus WB. In the 72.4% of patients receiving antiviral therapy, monitoring with plasma CMV-DNAemia versus WB CMV-DNAemia could delay treatment interruption by 7-14 days. Discontinuation of therapy based on WB monitoring did not result in relapsed infection in any patients. Highly different EBV-DNA kinetics in WB and plasma were observed due to lower positivity in plasma; EBV positive samples with a quantitative result in both blood compartments were observed in only 11.5% of cases. Our results emphasize the potential role of WB as specimen type for post-KT surveillance of both infections for disease prevention and management.

Cytomegalovirus and Epstein-Barr Virus DNA Kinetics in Whole Blood and Plasma of Allogeneic Hematopoietic Stem Cell Transplantation Recipients.

Currently, no consensus has been reached on the optimal blood compartment to be used for surveillance of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNAemia. Although several comparative studies have been performed correlating CMV and EBV DNA loads in whole blood (WB) versus plasma, to our knowledge, no studies to date have analyzed the kinetics of both viruses in the 2 blood compartments. In this retrospective noninterventional multicenter cohort study, the kinetics of CMV and EBV DNA in 121 hematopoietic stem cell transplantation (HSCT) recipients were investigated by analyzing in parallel 569 and 351 paired samples from 80 and 58 sequential episodes of CMV and EBV DNAemia, respectively. Unlike previous studies, this study used a single automated molecular method that was CE-marked and Food and Drug Administration-approved for use in quantifying CMV and EBV DNA in both plasma and WB. Furthermore, the complete viral replication kinetics of all episodes (including both the ascending and the descending phases of the active infection) was examined in each patient. The previously observed overall correlation between CMV DNA levels in WB and plasma was confirmed (Spearman's ρ = .85; P < .001). However, although WB and plasma CMV DNAemia reached peak levels simultaneously, in the ascending phase, the median CMV DNA levels in plasma were approximately 1 log10 lower than WB. Furthermore, in patients who received preemptive therapy, CMV DNA showed a delayed decrease in plasma compared with WB. A lower correlation between EBV DNA levels in plasma versus WB was found (Spearman's ρ = .61; P < .001). EBV DNA kinetics was not consistent in the 2 blood compartments, mostly due to the lower positivity in plasma. Indeed, in 19% of episodes, EBV DNA was negative at the time of the EBV DNA peak in WB. Our results suggest a preferential use of WB for surveillance of CMV and EBV infection in HSCT recipients.