Skin IL-17A and IFN-γ Production Correlate with Disease Severity in Patients with Psoriasis and Streptococcal Infection.

Psoriasis is a multisystemic inflammatory disorder mainly involving the skin and joints, whose etiopathogenesis is still not completely understood. An association with streptococcal throat infection has been suggested. We aim to investigate a correlation between IL-17A and IFN-γ production by T cells infiltrating skin lesions and PASI in 313 patients with psoriasis, compared with that in 252 healthy controls. The phenotype of ß-hemolytic Streptococci-specific infiltrating T cells in skin lesions was evaluated and characterized for IFN-γ, IL-4, and IL-17A production. In addition, PBMCs were tested by ELISpot for IFN-γ and IL-17A after streptococcal antigen exposure. A total of 64 of 313 (20.4%) patients with psoriasis had throat streptococcal infection. Of the 3,868 skin-derived T-cell clones from psoriasis with streptococcal infection, 66% proliferated in response to ß-hemolytic Streptococci antigens. Most ß-hemolytic Streptococci-specific T cells displayed T helper 17 and T helper 1 phenotypes. The levels of IFN-γ and IL-17A secreted by skin-infiltrating T cells of patients with psoriasis significantly correlated with PASI score. In ß-hemolytic Streptococci-positive patients, IFN-γ and IL-17A production by peripheral blood T cells after stimulation with streptococcal antigens was quantified by ELISpot. The results obtained may suggest ELISpot as a useful diagnostic tool to identify patients with psoriasis that may deserve antibiotic treatment.

A Questionnaire Integrated with the Digital Medical Record Improved the Coverage of a Control Program for Congenital Chagas Disease in Tuscany, Italy.

The leading route of Chagas disease transmission in nonendemic countries is congenital. However, policies concerning screening, prevention, and management of congenital Chagas disease are rare in these settings. Since 2012, serological screening for Chagas disease should be provided for pregnant women at risk in Tuscany, Italy according to a Regional resolution. Due to difficulties in the implementation, in November 2019, a checklist aimed at identifying pregnant women at risk for Chagas disease was introduced in digital clinical records at Careggi University Hospital, Florence, Italy. In order to evaluate the effectiveness of the "Chagas checklist", data about the number of deliveries by women at risk and their screening coverage between 2012 and June 2022 were collected. Out of 1348 deliveries by women at risk, 626 (47%) Trypanosoma cruzi serology tests were performed during the study period. The annual screening coverage increased from an average of 40.3% between 2012 and 2019 to 75.7% between 2020 and June 2022, underlining the big impact of the checklist. Four Chagas disease serological tests out of 626 (0.6%) resulted positive, corresponding to 2 affected women. No cases of congenital transmission occurred. The study showed that a simple digital tool led to a tangible improvement in the coverage of the screening program; its application in a setting where digital charts are available will contribute to the control and elimination of congenital Chagas disease.

Nosocomial outbreak by NDM-1-producing Klebsiella pneumoniae highly resistant to cefiderocol, Florence, Italy, August 2021 to June 2022.

A nosocomial outbreak by cefiderocol (FDC)-resistant NDM-1-producing Klebsiella pneumoniae (NDM-Kp) occurred in a large tertiary care hospital from August 2021-June 2022 in Florence, Italy, an area where NDM-Kp strains have become endemic. Retrospective analysis of NDM-Kp from cases observed in January 2021-June 2022 revealed that 21/52 were FDC-resistant. The outbreak was mostly sustained by clonal expansion of a mutant with inactivated cirA siderophore receptor gene, which exhibited high-level resistance to FDC (MIC ≥ 32 mg/L) and spread independently of FDC exposure.

SARS-CoV-2 infection and vaccination trigger long-lived B and CD4+ T lymphocytes with implications for booster strategies.

BACKGROUNDImmunization against SARS-CoV-2, the causative agent of COVID-19, occurs via natural infection or vaccination. However, it is currently unknown how long infection- or vaccination-induced immunological memory will last.METHODSWe performed a longitudinal evaluation of immunological memory to SARS-CoV-2 up to 1 year after infection and following mRNA vaccination in naive individuals and individuals recovered from COVID-19 infection.RESULTSWe found that memory cells are still detectable 8 months after vaccination, while antibody levels decline significantly, especially in naive individuals. We also found that a booster injection is efficacious in reactivating immunological memory to spike protein in naive individuals, whereas it was ineffective in previously SARS-CoV-2-infected individuals. Finally, we observed a similar kinetics of decay of humoral and cellular immunity to SARS-CoV-2 up to 1 year following natural infection in a cohort of unvaccinated individuals.CONCLUSIONShort-term persistence of humoral immunity, together with the reduced neutralization capacity versus the currently prevailing SARS-CoV-2 variants, may account for reinfections and breakthrough infections. Long-lived memory B and CD4+ T cells may protect from severe disease development. In naive individuals, a booster dose restored optimal anti-spike immunity, whereas the needs for vaccinated individuals who have recovered from COVID-19 have yet to be defined.FUNDINGThis study was supported by funds to the Department of Experimental and Clinical Medicine, University of Florence (Project Excellence Departments 2018-2022), the University of Florence (project RICTD2122), the Italian Ministry of Health (COVID-2020-12371849), and the region of Tuscany (TagSARS CoV 2).

First-dose mRNA vaccination is sufficient to reactivate immunological memory to SARS-CoV-2 in subjects who have recovered from COVID-19.

The characterization of the adaptive immune response to COVID-19 vaccination in individuals who recovered from SARS-CoV-2 infection may define current and future clinical practice. To determine the effect of the 2-dose BNT162b2 mRNA COVID-19 vaccination schedule in individuals who recovered from COVID-19 (COVID-19-recovered subjects) compared with naive subjects, we evaluated SARS-CoV-2 Spike-specific T and B cell responses, as well as specific IgA, IgG, IgM, and neutralizing antibodies titers in 22 individuals who received the BNT162b2 mRNA COVID-19 vaccine, 11 of whom had a previous history of SARS-CoV-2 infection. Evaluations were performed before vaccination and then weekly until 7 days after second injection. Data obtained clearly showed that one vaccine dose is sufficient to increase both cellular and humoral immune response in COVID-19-recovered subjects without any additional improvement after the second dose. On the contrary, the second dose proved mandatory in naive subjects to further enhance the immune response. These findings were further confirmed at the serological level in a larger cohort of naive (n = 68) and COVID-19-recovered (n = 29) subjects, tested up to 50 days after vaccination. These results question whether a second vaccine injection in COVID-19-recovered subjects is required, and indicate that millions of vaccine doses may be redirected to naive individuals, thus shortening the time to reach herd immunity.

Ceftazidime-Avibactam Use for Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Infections: A Retrospective Observational Multicenter Study.

BACKGROUND: A growing body of observational evidence supports the value of ceftazidime-avibactam (CAZ-AVI) in managing infections caused by carbapenem-resistant Enterobacteriaceae. METHODS: We retrospectively analyzed observational data on use and outcomes of CAZ-AVI therapy for infections caused by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) strains. Multivariate regression analysis was used to identify variables independently associated with 30-day mortality. Results were adjusted for propensity score for receipt of CAZ-AVI combination regimens versus CAZ-AVI monotherapy. RESULTS: The cohort comprised 577 adults with bloodstream infections (n = 391) or nonbacteremic infections involving mainly the urinary tract, lower respiratory tract, and intra-abdominal structures. All received treatment with CAZ-AVI alone (n = 165) or with ≥1 other active antimicrobials (n = 412). The all-cause mortality rate 30 days after infection onset was 25% (146/577). There was no significant difference in mortality between patients managed with CAZ-AVI alone and those treated with combination regimens (26.1% vs 25.0%, P = .79). In multivariate analysis, mortality was positively associated with presence at infection onset of septic shock (P = .002), neutropenia (P < .001), or an INCREMENT score ≥8 (P = .01); with lower respiratory tract infection (LRTI) (P = .04); and with CAZ-AVI dose adjustment for renal function (P = .01). Mortality was negatively associated with CAZ-AVI administration by prolonged infusion (P = .006). All associations remained significant after propensity score adjustment. CONCLUSIONS: CAZ-AVI is an important option for treating serious KPC-Kp infections, even when used alone. Further study is needed to explore the drug's seemingly more limited efficacy in LRTIs and potential survival benefits of prolonging CAZ-AVI infusions to ≥3 hours.

Arbo-Score: A Rapid Score for Early Identification of Patients with Imported Arbovirosis Caused by Dengue, Chikungunya and Zika Virus.

BACKGROUND: Chikungunya (CHIKV), Dengue (DENV), and Zika (ZIKV) viruses present significant clinical and epidemiological overlap, making an accurate and rapid diagnosis challenging. Timely activation of preventive vector control measures is crucial to avoid outbreaks in non-endemic settings. Diagnosis is based on combination of serological and molecular assays which could be time consuming and sometimes disappointing. METHODS: We report the results of a retrospective case-control study carried out at a tertiary teaching hospital in Italy, including all febrile subjects returning from tropical countries during the period 2014-2019. Controls were travelers with other febrile illnesses who tested negative in laboratory analysis for CHIKV, DENV, ZIKV arbovirosis. A score weighted on the regression coefficients for the independent predictors was generated. RESULTS: Ninety patients were identified: 34 cases (22 DENV, 4 CHIKV, and 8 ZIKV) and 56 controls. According to our results, myalgia, cutaneous rash, absence of respiratory symptoms, leukopenia, and hypertransaminasemia showed the strongest association with arbovirosis. Combining these variables, we generated a scoring model that showed an excellent performance (AUC 0.93). The best cut-off (>=2) presented a sensitivity of 82.35% and specificity of 96.43%. CONCLUSION: A handy and simple score, based on three clinical data (myalgia, cutaneous rash and absence of respiratory symptoms) and two laboratory results (leukopenia and hypertransaminasemia), provides a useful tool to help diagnose arboviral infections and appropriately activate vector control measures in order to avoid local transmission.

Cell-mediated and humoral adaptive immune responses to SARS-CoV-2 are lower in asymptomatic than symptomatic COVID-19 patients.

The characterization of cell-mediated and humoral adaptive immune responses to SARS-CoV-2 is fundamental to understand COVID-19 progression and the development of immunological memory to the virus. In this study, we detected T-cells reactive to SARS-CoV-2 proteins M, S, and N, as well as serum virus-specific IgM, IgA, IgG, in nearly all SARS-CoV-2 infected individuals, but not in healthy donors. Virus-reactive T cells exhibited signs of in vivo activation, as suggested by the surface expression of immune-checkpoint molecules PD1 and TIGIT. Of note, we detected antigen-specific adaptive immune response both in asymptomatic and symptomatic SARS-CoV-2 infected subjects. More importantly, symptomatic patients displayed a significantly higher magnitude of both cell-mediated and humoral adaptive immune response to the virus, as compared to asymptomatic individuals. These findings suggest that an uncontrolled adaptive immune response contribute to the development of the life-threatening inflammatory phase of the disease. Finally, this study might open the way to develop effective vaccination strategies.

Early discharge criteria in patients with acute bacterial skin and skin structure infections in a large tertiary-care teaching hospital in Florence, Italy.

The study is aimed at retrospectively estimating the percentage of inpatients with severe acute bacterial skin and skin structure infections (ABSSSI) who met the early discharged (ED) criteria adapted from Nathwani et al. (Int J Antimicrob Agents. 2016 Aug;48(2):127-36) and to calculate the number of hospitalization days that could be potentially saved. A retrospective study was conducted in a tertiary care hospital in Florence, Italy. We included all patients admitted for cellulitis and post-surgical infections from 2014 to 2017. Demographic and clinical data were obtained from electronic medical records. We a priori defined the following as a risk factor for non-adherence (RFNA): active or on methadone intravenous drug users, homeless, migrants without health care assistance, and patients who need a caregiver to take prescribed medications. One hundred sixty-two subjects were enrolled. Of them, 94 (58.0%) were male, and 113 (69.7%) had cellulitis/erysipelas. A microbiological isolate was obtained in 51 patients (31.4%); Staphylococcus aureus was the most frequent (47%). Eighty-four (51.8%) were ED suitable, with 258 (49.0%) patient days potentially saved. Among the 78 not ED suitable patients, the most common reason for prolonged length of stay (LOS) was having at least one RFNA (34.6%). Fourteen (18.0%) had one RFNA. Half of the patients admitted in our hospital met the ED criteria with a sparing close to 50% in terms of hospitalization days. Unstable social and personal factors were the most frequent causes for prolonged LOS. In this selected subset of patients, more recent and easier to administer treatments, including long-acting agents, could be proposed.

Role of place of acquisition and inappropriate empirical antibiotic therapy on the outcome of extended-spectrum ß-lactamase-producing Enterobacteriaceae infections.

The impact of inappropriate empirical antibiotic therapy (IEAT) on the outcome of severe infections due to extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-Ent) remains unclear. Current evidence is limited by study design and lack of confounder control. The main objective of this study was to define the outcome of severe infections due to ESBL-Ent according to clinical parameters and place of infection acquisition. Adult hospitalised patients with ESBL-Ent infections were included in a 3-year multicentre prospective study. Primary outcomes were IEAT rates and crude mortality of severe infections, adjusted by place of acquisition [community-acquired infection (CAI), healthcare-associated infection (HCAI) and hospital-acquired infection (HAI)]. Among 729 patients, 519 (71.2%) were diagnosed with HAI, 176 (24.1%) with HCAI and 34 (4.7%) with CAI. Moreover, 32.9% of patients received IEAT; higher rates of IEAT were observed in pneumonia (23%) and deep surgical site infections (19%). HCAIs were more frequently associated with IEAT than HAIs (48.3% vs. 27.9%; OR = 1.7, 95% CI 1.2-2.4). The overall mortality rate for severe infections (n = 264) was 12.1% and was significantly higher in HCAIs (20%) than HAIs (10%) (RR = 2.3, 95% CI 1.01-5.3). IEAT significantly increased the risk of mortality in bloodstream infections (RR = 8.3, 95% CI 2-46.3). Rates of IEAT and overall mortality of ESBL-Ent severe infections were higher in HCAIs than HAIs. Prompt diagnosis of patients with severe HCAIs due to ESBL-Ent is essential since these infections receive high rates of IEAT and significantly higher mortality than HAIs [ClinicalTrials.gov Identifier: NCT00404625].

Evaluation of a new rapid fluorescence immunoassay for the diagnosis of dengue and Zika virus infection.

BACKGROUND: Dengue (DENV) and Zika virus (ZIKV) are important mosquito-transmitted viruses. OBJECTIVES: To investigate the performance of Standard F, Fluorescence Immunoassay (FIA, SD Biosensor Inc., Suwon, South Korea) providing results in 15 min to detect DENV IgG, IgM and NS1Ag, and ZIKV IgG, IgM, and Ag. STUDY DESIGN: A well-characterized panel of patient samples (11 acute DENV, 11 acute ZIKV, 10 past DENV, 10 past ZIKV infection, 36 with other conditions) were tested with the FIA test. RESULTS: In acute DENV infection, the combination of FIA-NS1Ag and/or IgM positivity showed a sensitivity of 100%. In past DENV, FIA-IgG test showed a sensitivity of 70%. Specificity of FIA-DENV NS1Ag, IgG, and IgM was 87.5%, 83.5%, and 91.7%, respectively. The sensitivity of FIA-ZIKV IgM and FIA-ZIKV Ag, in confirmed acute infection, was 72.7% and 9.1%, respectively. FIA-ZIKV Ag did not improve the sensitivity in detecting acute ZIKV infection, being positive only in one IgM positive sample. In past ZIKV infection (32-183 days after symptom onset), FIA-ZIKV IgG and IgM showed a sensitivity of 40% and 80% respectively, generating an overall 90% sensitivity. Specificity of FIA-ZIKV Ag, IgM, and IgG was 92.6%, 100%, and 97%, respectively. CONCLUSION: FIA test, a rapid and easy to perform assay, showed high sensitivity to detect acute DENV infection, but lower in acute ZIKV infection. In past ZIKV infections, the best performance of FIA test is obtained by combining detection of IgG and IgM.

Seroprevalence of West Nile and dengue virus in the human population of the Bolivian Chaco.

To determine the seroprevalence of antibodies against dengue virus (DENV) and West Nile virus (WNV) in the human population of the Bolivian Chaco, we tested 256 inhabitants of two rural communities. The seroprevalence, confirmed by plaque reduction neutralization test, was 7.8% and 2.7% for DENV and WNV, respectively.

Evaluation of candidemia and antifungal consumption in a large tertiary care Italian hospital over a 12-year period.

PURPOSE: An early adequate antifungal therapy based on the knowledge of local epidemiology can reduce the candidemia-attributable mortality and the length of hospitalization. We performed a retrospective study to analyze the epidemiology of candidemia and the antifungal consumption in our hospital. METHODS: We analyzed Candida spp. isolated from the blood, and their susceptibility profile from 2005 to 2016 in Careggi University Hospital, Florence, Italy. We also performed a stratified analysis by clinical setting where Candida spp. were isolated (Medical Wards, Surgery, Intensive Care Unit-ICU). Then, we retrospectively reviewed the annual consumption of antifungal agents and calculated the defined daily dosing for 10,000 hospital days. RESULTS: The rate of candidemia was higher in ICU than other settings and Candida albicans was the first cause of candidemia (61.2%). After adjustment for hospital days, the rate of C. albicans showed a statistically significant parabolic trend (p < 0.001), with a peak of incidence in 2010. After 2010, we observed a reduction of candidemia due to both C. albicans and non-albicans species. Between 2005 and 2015, we reported an increasing increased use of echinocandins. As far as resistance profile is concerned, only one Candida glabrata isolate was resistant to caspofungin (1.9%) and 30% of C. glabrata were resistant to fluconazole. CONCLUSIONS: Our data describe C. albicans as the first cause of candidemia in all the studied settings and the low rate of echinocandin resistance, despite their increased use over the study period. ICU was confirmed as the setting with the highest incidence of candidemia.

The effect of merging two infectious disease units on hand hygiene adherence in Italy.

BACKGROUND: Healthcare-associated infections (HAIs) are common and harmful to patients. Effective hand hygiene can help prevent HAIs, however, suboptimal healthcare worker hand hygiene remains problematic across the globe. This study analyses the impact of organisational changes on hand hygiene. METHODS: This observational study assessed hand hygiene by different professions before and after a merger of a recently combined infectious diseases (ID) unit coupled with a qualitative study about barriers to optimal hand hygiene. Direct observations were compared with previous data collected on both units before they merged. We also conducted focus groups with the doctors and nurses about hand hygiene. RESULTS: After two ID units merged in 2013, we observed 681 provider-patient interactions. We compared these with a previous observation period in 2012. Hand hygiene adherence among nurses significantly declined after the merger (from 36% to 24%, P <0.001). However, adherence among doctors increased from 51% to 63% after the merger (P = 0.004). Data from the focus groups revealed a gap between doctor and nurses perceptions of education and goal adherence rates. CONCLUSIONS: Our findings underscore the important role played by effective unit leaders to prevent infection. We found long-term sustainability of hand hygiene practices among doctors. However, adherence among nurses was substantially lower.

The effect of leadership on hand hygiene: assessing hand hygiene adherence prior to patient contact in 2 infectious disease units in Tuscany.

We assessed hand hygiene adherence in 2 infectious disease units. In one unit, adherence declined slightly from year 1 (84.2%) to year 4 (71.0%) after a multimodal intervention but remained much higher than before intervention. Adherence dropped in the second unit after a loss of leadership (from 50.7% to 5.7%). Strong leadership presence may improve hand hygiene adherence.

Epidemiology and genetic characteristics of extended-spectrum ß-lactamase-producing Gram-negative bacteria causing urinary tract infections in long-term care facilities.

OBJECTIVES: To assess risk factors for acquiring extended-spectrum ß-lactamase-producing Gram-negative bacteria (ESBL+ GN) causing urinary tract infections (UTIs) in long-term care facilities (LTCFs). METHODS: A prospective case-case-control study was carried out. In the first study, cases were defined as patients harbouring ESBL+ GN, while, in the second study, cases were defined as patients harbouring ESBL-negative (ESBL-) GN. Controls were selected by simple random sampling from patients without GN infection. ESBL determinants were characterized by hybridization, and confirmed by PCR and sequencing. RESULTS: The study involved 297 LTCF patients (99 with ESBL+ GN UTI, 99 with ESBL- GN UTI and 99 without GN infection). ESBL+ GN UTIs were due to Escherichia coli (64%), Proteus mirabilis (25%) and Klebsiella pneumoniae (11%). The CTX-M-type enzymes were the most prevalent (73% of isolates), whereas TEM- and SHV-type ESBLs and AmpC-type enzymes were less prevalent (10%, 2% and 15% of isolates, respectively). Patients with ESBL+ GN UTI were more likely to have a permanent urinary catheter (OR 15, 95% CI 6.9-30.5) and to have received antimicrobial therapy in the previous 30 days (OR 4, 95% CI 1.2-10.9). After adjusting for type, dosage and duration of antibiotic, exposure to ≥7 days of quinolones and third-generation cephalosporins was associated with the highest risk of ESBL+ GN UTI development (OR 7, 95% CI 1.2-40). Independent risk factors for acquiring ESBL- GN UTIs were previous surgical procedures (OR 2, 95% CI 1.1-4) and the presence of a urinary catheter (OR 8, 95% CI 4-16). No specific antibiotics remained a significant risk for ESBL- GN UTI after adjusting for demographic and clinical risk factors. CONCLUSIONS: Exposure to ≥7 days of quinolones and third-generation cephalosporins significantly increases the risk of ESBL+ GN UTI. Interventions aimed at improving compliance with antimicrobial stewardship principles should be further developed and implemented in LTCFs.

Epidemiology and clinical relevance of microbial resistance determinants versus anti-Gram-positive agents.

Gram-positive pathogens are a major cause of community-acquired and hospital-acquired infections, and exhibit a remarkable ability to develop antibiotic resistance. Methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-resistant enterococci (GRE) and multidrug-resistant pneumococci are currently the major resistance challenges among Gram-positives, due to their global dissemination and overall clinical impact. The mechanisms of evolution of these resistance phenotypes are based on a diverse array of mutational events and gene transfer phenomena carried out by several types of mobile genetic elements, followed by the dissemination of successful resistant clones. Resistance to glycopeptides in staphylococci remains uncommon, likely due to fitness issues. Resistance to the new anti-Gram-positive agents (linezolid, daptomycin and tigecycline) overall remains very rare. However, a transferable resistance mechanism to linezolid, mediated by ribosomal target modification by the Cfr protein, has recently emerged among S. aureus, being a matter of raising concern. Linezolid resistance among enterococci and coagulase-negative staphylococci is also increasingly reported. Moreover, a role for antibiotic resistance has been advocated in the recent increase of Clostridium difficile infection (CDI) associated with the emergence of hypervirulent strains.