Role of IgG and IgM and proinflammatory non-specific markers in the diagnosis and prognosis of COVID-19 patients stratified by number of positive SARS-CoV-2 genes.

BACKGROUND: A prompt set of suitable biomarkers is needed in suspected COVID-19 patients. This study aims to assess patients positive for one or more gene associated with the C reactive protein (CRP) and procalcitonin (PCT) as non-specific pro-inflammatory markers and IgG and IgM kinetic as specific diagnostic and prognostic tools in SARS-CoV-2 RT-PCR positive patients. METHODS: We enrolled 101 patients within a two month time span (March 26th, 2020 to May 31st, 2020). A reverse transcription-Real-Time PCR assay on nasopharyngeal/oropharyngeal swabs was used for SARS-CoV-2 identification. Serum anti-SARS-CoV-2 IgM and IgG were measured by enzyme immunoassay, PCT levels by Enzyme linked fluorescent assay (ELFA)and CRP by nephelometry. RESULTS: We found that older patients were significantly associated with a worse prognosis. Serum IgM levels were significantly lower during the late stage of the disease, regardless of the presence of one or three genes and patients' outcome. On the contrary, IgG levels exhibited a higher concentration in the late phases of the illness, regardless of the gene found or patients' prognosis. With the exception of the very first sample tested, an increase in CRP in surviving patients (both one and three genes) and a time-dependent decrease of deceased patients CRP was found. PCT levels were always within the normal reference range. The difference between one gene and three genes patients was significant during late disease stages regarding IgG levels and also between three genes survivors versus three genes deceased, where the IgG levels were progressively increasing over time. CONCLUSIONS: The relevant finding of the present study is the significant and consistent increase of IgG and IgM in deceased patients. The associated evaluation of antibody kinetics and non specific inflammatory markers (CRP and PCT) in positive patients stratified according to the presence of one gene or three genes could help the clinician in both the diagnosis and prognosis of COVID-19 patients.

Omic insights into various ceftazidime-avibactam-resistant Klebsiella pneumoniae isolates from two southern Italian regions.

Ceftazidime-avibactam (CZA) is one of the best therapeutic options available for infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing bacteria. However, sporadic reports of CZA-resistant strains have been rapidly increasing in patients. Herein, we provide detailed case reports of the emergence of ceftazidime-avibactam resistance to identify their resistome and virulome using genomic molecular approaches. Sixteen isolates were collected from 13 patients at three hospitals in Catania and Catanzaro (Italy) between 2020-2021. Antimicrobial susceptibility was determined by broth microdiluition. The samples included in study were analyzed for resistome, virulome and Sequence Type (ST) using Whole Genome Sequencing (WGS). All strains were resistant to ceftazidime/avibactam, ciprofloxacin, extended-spectrum cephalosporins and aztreonam, 13/16 to meropenem, 8/16 to colistin and 7/16 to fosfomycin; 15/16 were susceptible to meropenem/vaborbactam; all strains were susceptible to cefiderocol. Molecular analysis showed circulation of three major clones: ST101, ST307 and ST512. In 10/16 strains, we found a bla KPC-3 gene; in 6/16 strains, four different bla KPC variants (bla KPC28-31-34-50) were detected. A plethora of other beta-lactam genes (bla SHV28-45-55-100-106-187-205-212, bla OXA1-9-48, bla TEM-181 and bla CTX-M-15) was observed; bla OXA-9 was found in ST307 and ST512, instead bla OXA48 in one out four ST101 strains. With regard to membrane permeability, ompK35 and ompK36 harbored frameshift mutations in 15/16 strains; analysis of ompK37 gene revealed that all strains harbored a non-functional protein and carry wild-type PBP3. There is an urgent need to characterize the mechanisms underlying carbapenem resistance and the intrinsic bacterial factors that facilitate the rapid emergence of resistance. Furthermore, it is becoming increasingly important to explore feasible methods for accurate detection of different KPC enzymes.

Multidisciplinary approach to a septic COVID-19 patient undergoing veno-venous extracorporeal membrane oxygenation and receiving thoracic surgery.

A multidisciplinary approach appears to be fundamental for the treatment of critically ill patients with COVID-19, improving clinical outcomes, even in the most severe cases. Such severe cases are advisable to be collegially discussed between intensivists, surgeons, infectious disease, and other physicians potentially involved.

The Impact of Carbapenem Resistance on Mortality in Patients With Klebsiella Pneumoniae Bloodstream Infection: An Individual Patient Data Meta-Analysis of 1952 Patients.

INTRODUCTION: Available evidence from observational studies and meta-analyses has highlighted an increased mortality in patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections (BSI) compared with their carbapenem-susceptible (CSKP) counterparts, but the exact reasons for this outcome difference are still to be determined. METHODS: We updated the search of a previous meta-analysis through four databases up to April 2018. A two-stage individual-patient data (IPD) meta-analysis was conducted, building an adjusting model to account for age, comorbidities and activity of empirical and targeted antimicrobial therapy. The protocol was registered on PROSPERO (identifier: CRD42018104256). RESULTS: IPD data were obtained from 14 out of 28 eligible observational studies. A total of 1952 patients were investigated: 1093 in the CRKP group and 859 in the CSKP group. Patients with CRKP-BSI had a twofold risk of death compared with CSKP-infected patients [adjusted odds ratio (aOR) 2.17; 95% confidence interval (CI) 1.56-3.04; I2 = 44.1%]. Mortality was higher in patients with CRKP BSI, in both the subgroup of absent/inactive (aOR 1.75; 95% CI 1.24-2.47; I2 = 0) and of active initial therapy (aOR 2.66; 95% CI 1.70-4.16; I2 = 16%) as well as in case of active targeted therapy (aOR 2.21; 95% CI 1.36-3.59; I2 = 58%). CONCLUSION: Resistance to carbapenem is associated with worse outcome in patients with BSI by Klebsiella pneumoniae even adjusting for comorbidities and treatment appropriateness according to in vitro activity of empirical and targeted therapy. This applies to a scenario dominated by colistin-based therapies for CRKP. Further studies are needed to compare the mortality difference between CRKP and CSKP cases in the light of new anti-CRKP antimicrobials.

Identification of pmrB mutations as putative mechanism for colistin resistance in A. baumannii strains isolated after in vivo colistin exposure.

Colistin resistance among extensively-resistant Acinetobacter baumannii isolates is a serious health-care problem. Alterations in PmrA-PmrB two-component system have been associated with resistance to colistin. We investigated three pairs of colistin-susceptible and colistin-resistant A. baumannii, sequentially isolated from three patients before and after colistin treatment, respectively. The pmrA and pmrB genes were sequenced by Sanger method. Amino acidic positions and their effect on protein were predicted by InterPro and PROVEAN tools. Expression of pmrA, pmrB and pmrC genes was assessed by semi-quantitative reverse transcription-PCR (qRT-PCR). We found three different nonsynonymous substitutions P233T, E301G and L168K in pmrB coding region, each one in a different colistin resistance strain. The E301G and L168K substitutions represent novel mutations in pmrB, not previously described. Relative expression of pmrA, pmrB and pmrC mRNA increased in all colistin resistant strains. In our study, pmrB substitutions were associated with pmrC over-expression and colistin resistance. Further studies are necessary to understand their impact on modification of lipid A components.

Prosthetic valve endocarditis: predictors of early outcome of surgical therapy. A multicentric study.

OBJECTIVES: Prosthetic valve endocarditis (PVE) is an uncommon yet dreadful complication in patients with prosthetic valves that requires a distinct analysis from native valve endocarditis. The present study aims to investigate independent risk factors for early surgical outcomes in patients with PVE. METHODS: A retrospective cohort study was conducted in 8 Italian Cardiac Surgery Units from January 2000 to December 2013 by enrolling all PVE patients undergoing surgical treatment. RESULTS: A total of 209 consecutive patients were included in the study. During the study period, the global rate of surgical procedures for PVE among all operations for isolated or associated valvular disease was 0.45%. Despite its rarity this percentage increased significantly during the second time frame (2007-2013) in comparison with the previous one (2000-2006): 0.58% vs 0.31% (P < 0.001). Intraoperative and in-hospital mortality rates were 4.3% and 21.5%, respectively. Logistic regression analysis identified the following factors associated with in-hospital mortality: female gender [odds ratio (OR) = 4.62; P < 0.001], shock status (OR = 3.29; P = 0.02), previous surgical procedures within 3 months from the treatment (OR = 3.57; P = 0.009), multivalvular involvement (OR = 8.04; P = 0.003), abscess (OR = 2.48; P = 0.03) and urgent surgery (OR = 6.63; P < 0.001). CONCLUSIONS: Despite its rarity, PVE showed a significant increase over time. Up to now, in-hospital mortality after surgical treatment still remains high (>20%). Critical clinical presentation and extension of anatomical lesions are strong preoperative predictors for poor early outcome.

(1,3)-ß-d-Glucan-based antifungal treatment in critically ill adults at high risk of candidaemia: an observational study.

OBJECTIVES: To determine the effects of a strategy that uses serum (1,3)-ß-d-glucan (BDG) results for antifungal treatment of ICU patients at high risk of invasive candidiasis. PATIENTS AND METHODS: Adult patients admitted to the ICU from January 2012 to June 2014 were included if they exhibited sepsis at the time of BDG testing and they met Candida score components ≥3. A retrospective analysis of collected data was performed. RESULTS: In total, 198 patients were studied. Of 63 BDG-positive patients, 47 with candidaemia and 16 with probable Candida infection, all [31.8% (63/198)] received antifungal therapy. Of 135 BDG-negative patients, 110 [55.5% (110/198)] did not receive antifungal therapy, whereas 25 [12.6% (25/198)] were initially treated. Overall, antifungal therapy was started in 88 cases (44.4%), mostly with echinocandins. Antifungals were discontinued in 14 of 25 patients, as negative BDG results became available, and in 16 BDG-false-positive patients for whom subsequent findings allowed candidaemia (and other forms of invasive candidiasis) to be ruled out. Candidaemia was diagnosed only in one patient who did not receive prior antifungal therapy. The median antifungal therapy duration in candidaemic patients differed significantly from that in non-candidaemic patients [14 (IQR, 6-18) days versus 4 (IQR, 3-7) days; P < 0.001]. Using this approach, antifungal therapy was avoided in ∼73% of potentially treatable patients and it was shortened in another ∼20%. CONCLUSIONS: This study supports the use of serum BDG results in the management of systemic antifungal drug prescription in septic patients. These findings need to be confirmed in additional studies.

Antimicrobial-resistant Gram-negative bacteria in febrile neutropenic patients with cancer: current epidemiology and clinical impact.

PURPOSE OF REVIEW: In the recent years, several studies involving cancer patients have demonstrated a clear trend in the epidemiology of bacterial infections showing a shift in the prevalence from Gram-positive to Gram-negative bacteria and the extensive emergence of antimicrobial-resistant strains among Gram-negatives isolated from the blood. The aim of this systematic review was to examine the recent trends in epidemiology and antimicrobial resistance in Gram-negatives recovered from neutropenic cancer patients, with particular emphasis on the impact of antimicrobial resistance on the clinical outcome of severe infections caused by such microorganisms. RECENT FINDINGS: Overall, from 2007 to date, the rate of Gram-negative bacteria recovery ranged from 24.7 to 75.8% (mean 51.3%) in cancer patient cohorts. Escherichia coli represented the most common species (mean frequency of isolation 32.1%) among the Gram-negatives, followed by Pseudomonas aeruginosa (mean frequency of isolation 20.1%). An increasing frequency of Acinetobacter spp. and Stenotrophomonas maltophilia was also reported. Increased rates of multidrug-resistant Gram-negative strains have been highlighted among Enterobacteriaceae and nonfermenting Gram-negative rods, despite discontinuation of fluoroquinolone-based antibacterial prophylaxis for neutropenic patients. In addition, antimicrobial resistance and/or the inadequacy of empirical antibiotic treatment have been frequently linked to a worse outcome in cancer patients with bloodstream infections caused by Gram-negative isolates. SUMMARY: Sound knowledge of the local distribution of pathogens and their susceptibility patterns and prompt initiation of effective antimicrobial treatment for severe infections caused by Gram-negative bacteria are essential in cancer patients.

Safety and effectiveness of transvenous lead extraction in octogenarians.

INTRODUCTION: As the population ages, the number of elderly patients with implantable cardiac devices referred for transvenous lead extraction will dramatically increase in Western countries. The safety and effectiveness of lead extraction in elderly patients has not been well evaluated. We report the safety and effectiveness of transvenous lead extraction in octogenarians. METHODS AND RESULTS: From January 2005 to January 2011, we reviewed data from consecutive patients ≥ 80 years referred to our institutions for transvenous lead extraction because of cardiac device infection or lead malfunction. Clinical characteristics, procedural features, and periprocedural major and minor complications were compared between octogenarians and younger patients. Out of 849 patients undergoing lead extraction in the participating institutions during the study period, 150 (18%) patients were octogenarians (mean age 84 years; range 80-96; 64% males). A significantly higher percentage of octogenarians presented with chronic renal failure (55% vs 26%; P < 0.001), history of malignancy (22% vs 6%; P < 0.001), and chronic obstructive pulmonary disease (46% vs 19%; P < 0.001). Complete lead extraction rates were similar in the 2 age groups (97% in octogenarians vs 96% in patients <80 years; P = 0.39). Periprocedural death occurred in 2 (1.3%) patients ≥80 years and in 5 (0.72%) patients <80 years (P = 0.45 for comparison). No differences in terms of other periprocedural major and minor complications were found between the 2 age groups. CONCLUSION: Despite presenting with a significantly higher rate of comorbidities, transvenous lead extraction can be performed safely and successfully in octogenarians.

Factors associated with mortality in bacteremic patients with hematologic malignancies.

We conducted a retrospective cohort study to identify risk factors for mortality in a large cohort of hematologic patients with bacteremia. From 2000 through 2005, bacteremia was diagnosed in 217 patients with hematologic malignancies. The infections were caused only by Gram-positive organisms in 57.1% (124/217) cases and only by Gram-negative bacteria in 37.8% (82/217); the remaining 5.1% (11/217) were polymicrobial. The overall 30-day mortality rate was 20.3% (44/217). In multivariate analysis, significant predictors of mortality were prolonged neutropenia (P < 0.001), acute renal failure (P = 0.002), nosocomial bacteremia (P = 0.009), age >55 years (P = 0.007), and monomicrobial bacteremia due to antibiotic-resistant Gram-negative bacteria (P = 0.009). Reducing fatal outcomes associated with bacteremia in patients with hematologic malignancies is a challenge, and the emergence of resistance to the antimicrobials widely used in this setting is of great concern. Future infection trends must be carefully monitored and treatment guidelines adjusted accordingly.

Incidence and clinical impact of extended-spectrum-beta-lactamase (ESBL) production and fluoroquinolone resistance in bloodstream infections caused by Escherichia coli in patients with hematological malignancies.

OBJECTIVES: To identify risk factors for mortality in patients suffering from hematological malignancies with concurrent bacteremia caused by Escherichia coli. Particular attention was focused on defining the impact of extended-spectrum-beta-lactamase (ESBL) production and fluoroquinolone resistance by the bacterial isolates on mortality. MATERIALS AND METHODS: A retrospective eight-year cohort study design was employed. The outcome measured was death within 30 days of the first positive blood culture. Survivor and non-survivor subgroups were compared to identify predictors of mortality. RESULTS: A total of 62 episodes of bacteremia caused by E. coli were analyzed. The overall incidences of ESBL production and fluoroquinolone resistance were 41.9% and 62.9%, respectively. The overall 30-day mortality rate was 20.9% (13/62). In a multivariate analysis, significant predictors of mortality were inadequate initial antimicrobial therapy (OR=14.96, 95% CI 1.95-114.51; P=0.009), infection caused by ESBL-producing isolates (OR=8.84, 95% CI 1.48-52.91; P=0.01), and prolonged neutropenia (OR=8.10, 95% CI 1.29-50.57; P=0.02). CONCLUSIONS: Sound knowledge of the local distribution of pathogens and their susceptibility patterns and prompt initiation of effective antimicrobial treatment are essential in patients suffering from hematological malignancies with BSIs caused by E. coli.

Predictors of mortality in patients with bloodstream infections caused by extended-spectrum-beta-lactamase-producing Enterobacteriaceae: importance of inadequate initial antimicrobial treatment.

Bloodstream infections (BSI) caused by extended-spectrum beta-lactamase (ESBL)-producing organisms markedly increase the rates of treatment failure and death. We conducted a retrospective cohort analysis to identify risk factors for mortality in adult in-patients with BSI caused by ESBL-producing Enterobacteriaceae (ESBL-BSI). Particular attention was focused on defining the impact on the mortality of inadequate initial antimicrobial therapy (defined as the initiation of treatment with active antimicrobial agents >72 h after collection of the first positive blood culture). A total of 186 patients with ESBL-BSI caused by Escherichia coli (n = 104), Klebsiella pneumoniae (n = 58), or Proteus mirabilis (n = 24) were identified by our microbiology laboratory from 1 January 1999 through 31 December 2004. The overall 21-day mortality rate was 38.2% (71 of 186). In multivariate analysis, significant predictors of mortality were inadequate initial antimicrobial therapy (odds ratio [OR] = 6.28; 95% confidence interval [CI] = 3.18 to 12.42; P < 0.001) and unidentified primary infection site (OR = 2.69; 95% CI = 1.38 to 5.27; P = 0.004). The inadequately treated patients (89 of 186 [47.8%]) had a threefold increase in mortality compared to the adequately treated group (59.5% versus 18.5%; OR = 2.38; 95% CI = 1.76 to 3.22; P < 0.001). The regimens most commonly classified as inadequate were based on oxyimino cephalosporin or fluoroquinolone therapy. Prompt initiation of effective antimicrobial treatment is essential in patients with ESBL-BSI, and empirical decisions must be based on a sound knowledge of the local distribution of pathogens and their susceptibility patterns.

Partial protective effect of CCR5-Delta 32 heterozygosity in a cohort of heterosexual Italian HIV-1 exposed uninfected individuals.

Despite multiple sexual exposure to HIV-1 virus, some individuals remain HIV-1 seronegative (exposed seronegative, ESN). The mechanisms underlying this resistance remain still unclear, although a multifactorial pathogenesis can be hypothesised. Although several genetic factors have been related to HIV-1 resistance, the homozigosity for a mutation in CCR5 gene (the 32 bp deletion, i.e. CCR5-Delta32 allele) is presently considered the most relevant one. In the present study we analysed the genotype at CCR5 locus of 30 Italian ESN individuals (case group) who referred multiple unprotected heterosexual intercourse with HIV-1 seropositive partner(s), for at least two years. One hundred and twenty HIV-1 infected patients and 120 individuals representative of the general population were included as control groups. Twenty percent of ESN individuals had heterozygous CCR5-Delta 32 genotype, compared to 7.5% of HIV-1 seropositive and 10% of individuals from the general population, respectively. None of the analysed individuals had CCR5-Delta 32 homozygous genotype. Sequence analysis of the entire open reading frame of CCR5 was performed in all ESN subjects and no polymorphisms or mutations were identified. Moreover, we determined the distribution of C77G variant in CD45 gene, which has been previously related to HIV-1 infection susceptibility. The frequency of the C77G variant showed no significant difference between ESN subjects and the two control groups. In conclusion, our data show a significantly higher frequency of CCR5-Delta 32 heterozygous genotype (p = 0.04) among the Italian heterosexual ESN individuals compared to HIV-1 seropositive patients, suggesting a partial protective role of CCR5-Delta 32 heterozygosity in this cohort.