Journal of Microbiology Immunology and Infection最新文献

Background

The RECOVERY trial demonstrated that the use of dexamethasone is associated with a 36% lower 28-day mortality in hospitalized patients with COVID-19 on invasive mechanical ventilation. Nevertheless, the optimal timing to start dexamethasone remains uncertain.

Methods

We conducted a quasi-experimental study at National Taiwan University Hospital (Taipei, Taiwan) using propensity score matching to simulate a randomized controlled trial to receive or not to receive early dexamethasone (6 mg/day) during the first 7 days following the onset of symptoms. Treatment was standard protocol-based, except for the timing to start dexamethasone, which was left to physicians’ decision. The primary outcome is 28-day mortality. Secondary outcomes include secondary infection within 60 days and fulfilling the criteria of de-isolation within 20 days.

Results

A total of 377 patients with COVID-19 were enrolled. Early dexamethasone did not decrease 28-day mortality in all patients (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.97–1.10) or in patients who required O2 for severe/critical disease at admission (aOR, 1.05; 95%CI, 0.94–1.18); but is associated with a 24% increase in superinfection in all patients (aOR, 1.24; 95% CI, 1.12–1.37) and a 23% increase in superinfection in patients of O2 for several/critical disease at admission (aOR, 1.23; 95% CI, 1.02–1.47). Moreover, early dexamethasone is associated with a 42% increase in likelihood of delayed clearance of SARS-CoV-2 virus (adjusted hazard ratio, 1.42; 95% CI, 1.01–1.98).

Conclusion

An early start of dexamethasone (within 7 days after the onset of symptoms) could be harmful to hospitalized patients with COVID-19.

Background

Tuberculosis (TB) remains prevalent worldwide, and anti-TB drugs are associated with drug-induced liver injury (DILI). Statins have pleiotropic effects which may decrease inflammation and achieve immunomodulation. However, few studies have investigated the pleiotropic effects of statins on the risk of DILI. The purpose of this study was to investigate whether statins prevent anti-tuberculosis DILI among active TB patients on standard anti-TB drug therapy.

Methods

We conducted a hospital-based retrospective cohort study using claims data from the Integrated Medical Database of National Taiwan University Hospital (NTUH-iMD). Patients with a positive TB culture were included. The use of statins was defined as a daily equivalent dose >0.5 mg of pitavastatin. Deterioration in liver function was evaluated according to elevated liver enzyme levels. The primary and secondary endpoints were the DILI and the severe DILI. The prognostic value of statins was evaluated by Kaplan–Meier analysis, and Cox proportional hazards models.

Results

A total of 1312 patients with a diagnosis of TB and receiving anti-TB treatment were included. During the study period, 193 patients had the DILI and 140 patients had the severe DILI. Kaplan–Meier analysis showed a significant difference between the usual statin users and controls in the DILI. In multivariable Cox proportional hazards analysis, statins showed a protective effect against the primary and secondary endpoints. In addition, the protective effect of statins showed a dose–response relationship against the DILI.

Conclusion

Statin treatment had a protective effect against the risk of anti-TB DILI with a positive dose–response relationship.

Background

Cytomegalovirus (CMV) can cause infection and critical diseases in hematopoietic stem cell transplantation (HSCT) recipients. This study aimed to explore the cumulative incidence and risk factors for CMV infection and disease among HSCT recipients in Taiwan.

Methods

This retrospective cohort study using the Taiwan Blood and Marrow Transplantation Registry (TBMTR) included HSCT recipients between 2009 and 2018 in Taiwan. The primary outcome was cumulative incidence of CMV infection or disease at day 100 after HSCT. Secondary outcomes included day 180 cumulative incidence of CMV infection or disease, infection sites, risk factors for CMV infection or disease, survival analysis, and overall survival after CMV infection and disease.

Results

There were 4394 HSCT recipients included in the study (2044 auto-HSCT and 2350 allo-HSCT). The cumulative incidence of CMV infection and disease was significantly higher in allo-HSCT than in auto-HSCT patients at day 100 (53.7% vs. 6.0%, P < 0.0001 and 6.1% vs. 0.9%, P < 0.0001). Use of ATG (HR 1.819, p < 0.0001), recipient CMV serostatus positive (HR 2.631, p < 0.0001) and acute GVHD grades ≥ II (HR 1.563, p < 0.0001) were risk factors for CMV infection, while matched donor (HR 0.856, p = 0.0180) and myeloablative conditioning (MAC) (HR 0.674, p < 0.0001) were protective factors.

Conclusion

The study revealed a significant disparity in terms of the incidence, risk factors, and clinical outcomes of CMV infection and disease between auto and allo-HSCT patients. These findings underscore the importance of considering these factors in the management of HSCT recipients to improve outcomes related to CMV infections.

Background

Copper plays a role in urinary tract infection (UTI) and urinary copper content is increased during Proteus mirabilis UTI. We therefore investigated the effect of copper on uropathogenic P. mirabilis and the underlying mechanisms, focusing on the virulence associated aspects.

Methods

Mouse colonization, swarming/swimming assays, measurement of cell length, flagellin level and urease activity, adhesion/invasion assay, biofilm formation, killing by macrophages, oxidative stress susceptibility, OMPs analysis, determination of MICs and persister cell formation, RT-PCR and transcriptional reporter assay were performed.

Results

We found that copper-supplemented mice were more resistant to be colonized in the urinary tract, together with decreased swarming/swimming, ureases activity, expression of type VI secretion system and adhesion/invasion to urothelial cells and increased killing by macrophages of P. mirabilis at a sublethal copper level. However, bacterial biofilm formation and resistance to oxidative stress were enhanced under the same copper level. Of note, the presence of copper led to increased ciprofloxacin MIC and more persister cell formation against ampicillin. In addition, the presence of copper altered the outer membrane protein profile and triggered expression of RcsB response regulator. For the first time, we unveiled the pleiotropic effects of copper on uropathogenic P. mirabilis, especially for induction of bacterial two-component signaling system regulating fitness and virulence.

Conclusion

The finding of copper-mediated virulence and fitness reinforced the importance of copper for prevention and therapeutic interventions against P. mirabilis infections. As such, this study could facilitate the copper-based strategies against UTI by P. mirabilis.

Background

Patients with hematological malignancies (HM) were at a high risk of developing severe disease from coronavirus disease 2019 (COVID-19). We aimed to assess the clinical outcome of COVID-19 in hospitalized patients with HM.

Methods

Adult patients with HM who were hospitalized with a laboratory-confirmed COVID-19 between May, 2021 and November, 2022 were retrospectively identified. Primary outcome was respiratory failure requiring mechanical ventilation or mortality within 60 days after hospitalization. We also analyzed associated factors for de-isolation (defined as defervescence with a consecutive serial cycle threshold value > 30) within 28 days.

Results

Of 152 eligible patients, 22 (14.5%) developed respiratory failure or mortality in 60 days. Factors associated with developing respiratory failure that required mechanical ventilation or mortality included receipt of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) (adjusted hazards ratio [aHR], 5.10; 95% confidence interval [CI], 1.64–15.85), type 2 diabetes mellitus (aHR, 2.47; 95% CI, 1.04–5.90), lymphopenia at admission (aHR, 6.85; 95% CI, 2.45–19.15), and receiving <2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines (aHR, 3.00; 95% CI, 1.19–7.60). Ninety-nine (65.1%) patients were de-isolated in 28 days, against which two hazardous factors were identified: receipt of B-cell depletion therapies within one year prior to COVID-19 (aHR, 0.55, 95% CI, 0.35–0.87) and lymphopenia upon admission (aHR, 0.65; 95% CI, 0.43–1.00).

Conclusion

We found a high rate of respiratory failure and mortality among patients with HM who contracted the SARS-CoV-2. Factors associated with developing respiratory failure or mortality in 60 days included receipt of allo-HSCT, type 2 diabetes mellitus and lymphopenia upon admission. Having received ≥2 doses of vaccination conferred protection against clinical progression.

While the incidence of shigellosis has decreased in developed nations due to improved living conditions and healthcare systems, it remains prevalent in economically developing regions. In recent years, a resurgence of shigellosis has been observed in the United States, Europe, and Taiwan, primarily among men having sex with men and people living with human immunodeficiency virus, along with a rise in antimicrobial resistance. This study aims to review the historical epidemiological trends and drug resistance in shigellosis, with a focus on Taiwan. A comprehensive search was conducted using various databases and sources, including non-English literature in Japanese and Chinese. In developed countries, Shigella sonnei and Shigella flexneri are the most common species, while Shigella dysenteriae infections are sporadic. In Taiwan, the classification and prevalence of Shigella species have evolved over time, with S. flexneri and S. sonnei being the predominant strains. Fluoroquinolone resistance and azithromycin non-susceptibility are the ongoing threat. In conclusion, shigellosis remains a significant global health concern, with recent increases in certain populations and antimicrobial resistance. Further research is necessary to understand the clinical significance and risk factors associated with asymptomatic carriers and to assess the impact of behavioral modifications and interventions in high-risk populations.

Background

The coronavirus disease 2019 (COVID-19) pandemic has contributed to the spread of antimicrobial resistance, including carbapenem-resistant Enterobacterales.

Methods

This study utilized data from the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance program in Taiwan. Enterobacterales from patients with bloodstream infections (BSIs) were collected and subjected to antimicrobial susceptibility testing and β-lactamase gene detection using a multiplex PCR assay. Statistical analysis was conducted to compare susceptibility rates and resistance genes between time periods before (2018–2019) and during the COVID-19 pandemic (2020–2021).

Results

A total of 1231 Enterobacterales isolates were collected, predominantly Escherichia coli (55.6%) and Klebsiella pneumoniae (29.2%). The proportion of nosocomial BSIs increased during the COVID-19 pandemic (55.5% vs. 61.7%, p < 0.05). Overall, susceptibility rates for most antimicrobial agents decreased, with Enterobacterales from nosocomial BSIs showing significantly lower susceptibility rates than those from community-acquired BSIs. Among 123 Enterobacterales isolates that underwent molecular resistance mechanism detection, ESBL, AmpC β-lactamase, and carbapenemase genes were detected in 43.1%, 48.8% and 16.3% of the tested isolates, respectively. The prevalence of carbapenemase genes among carbapenem-resistant Enterobacterales increased during the pandemic, although the difference was not statistically significant. Two novel β-lactamase inhibitor combinations, imipenem-relebactam and meropenem-vaborbactam, preserved good efficacy against Enterobacterales. However, imipenem-relebactam showed lower in vitro activity against imipenem-non-susceptible Enterobacterales than that of meropenem-vaborbactam.

Conclusions

The COVID-19 pandemic appears to be associated with a general decrease in antimicrobial susceptibility rates among Enterobacterales causing BSIs in Taiwan. Continuous surveillance is crucial to monitor antimicrobial resistance during the pandemic and in the future.

Introduction

Aim of the study was the molecular characterization of 21 ceftazidime/avibactam resistant (CZA-R) Klebsiella pneumoniae strains, collected in the period October 2021–March 2022 from an Intensive Care COVID Unit in a Northern Italian Hospital.

Methods

After growth on selective/chromogenic culture media and susceptibility tests assessment, resistance genes content was ascertained for all the isolates by the HybriSpot 12 multiplexing, PCR and Whole-Genome Sequencing (WGS). Clonality was assessed by PFGE and MLST according to the Pasteur scheme. A SNPs-based phylogenetic tree was obtained comparing representative isolates and global genomes. The blaKPC gene horizontal transmission was evaluated by conjugation experiments. blaKPC-166 was cloned in a pCR2.1 vector and transformed in chemically competent TOP10 cells.

Results

Sixteen inpatients resulted positive for colonization and/or infection by KPC-producing K. pneumoniae (KPC-Kp) strains. The 21 CZA-R KPC-Kp isolates obtained showed MDR phenotype; susceptibility to meropenem was always retained. All the CZA-R KPC-Kp presented a novel blaKPC variant, named blaKPC-166, showing a single nucleotide substitution (T811C) compared to the blaKPC-94; but related to blaKPC-2.

Two different pulsotypes were detected

A in 18/21 and B in 1/21 cases, two strains from the same patient being untypable by PFGE. Interestingly, the outbreak was sustained by the high-risk clone ST307, although the ST22, ST6342, ST6418 and ST6811 have also been identified and associated to KPC-166. Worryingly, blaKPC-166 could be transferred horizontally and, after cloning, it conferred resistance to CZA.

Discussion

This novel variant confers CZA–resistance and carbapenems susceptibility restoration. As KPC-166 was found expressed by multiple Kp clones, greater efforts should be made to prevent the further dissemination of such strains in Italian clinical settings.

Background

The optimal timing for applying the BioFire FilmArray Pneumonia Panel (FAPP) in intensive care unit (ICU) patients with hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP) remains undefined, and there are limited data on its impact on antimicrobial stewardship.

Methods

This retrospective study was conducted at a referral hospital in Taiwan from November 2019 to October 2022. Adult ICU patients with HAP/VAP who underwent FAPP testing were enrolled. Patient data, FAPP results, conventional microbiological testing results, and the real-world impact of FAPP results on antimicrobial therapy adjustments were assessed. Logistic regression was used to determine the predictive factors for bacterial detection by FAPP.

Results

Among 592 respiratory specimens, including 564 (95.3%) endotracheal aspirate specimens, 19 (3.2%) expectorated sputum specimens and 9 (1.5%) bronchoalveolar lavage specimens, from 467 patients with HAP/VAP, FAPP testing yielded 368 (62.2%) positive results. Independent predictors for positive bacterial detection by FAPP included prolonged hospital stay (odds ratio [OR], 3.14), recent admissions (OR, 1.59), elevated C-reactive protein levels (OR, 1.85), Acute Physiology and Chronic Health Evaluation II scores (OR, 1.58), and septic shock (OR, 1.79). Approximately 50% of antimicrobial therapy for infections caused by Gram-negative bacteria and 58.4% for Gram-positive bacteria were adjusted or confirmed after obtaining FAPP results.

Conclusions

This study identified several factors predicting bacterial detection by FAPP in critically ill patients with HAP/VAP. More than 50% real-world clinical practices were adjusted or confirmed based on the FAPP results. Clinical algorithms for the use of FAPP and antimicrobial stewardship guidelines may further enhance its benefits.