Impact of Candida species on clinical outcomes in patients with suspected ventilator-associated pneumonia

Efficacy of Ceragenins in Controlling the Growth of Oral Microorganisms: Implications for Oral Hygiene Management

Ensuring proper dental hygiene is of paramount importance for individuals' general well-being, particularly for patients receiving medical care. There is a prevailing utilization of conventional oral hygiene items, including toothbrushes and mouthwashes, which have gained widespread acceptance; nevertheless, their limitations encourage investigating novel options in this domain. Our study indicates that ceragenins (CSAs) being lipid analogs of host defense peptides, well-recognized for their wide-ranging antimicrobial properties, may be a potentially efficacious means to augment oral hygiene in hospitalized individuals. We demonstrate that ceragenins CSA-13, CSA-44, and CSA-131 as well as undescribed to date CSA-255 display potent antimicrobial activities against isolates of fungi, aerobic, and anaerobic bacteria from Candida, Streptococcus, Enterococcus, and Bacteroides species, which are well-recognized representatives of microbes found in the oral cavity. These effects were further confirmed against mono- and dual-species fungal and bacterial biofilms. While the ceragenins showed similar or slightly diminished efficacy compared to commercially available mouthwashes, they demonstrated a highly favorable toxicity profile toward host cells, that may translate into better maintenance of host mucosal membrane stability. This suggests that incorporating ceragenins into oral hygiene products could be a valuable strategy for reducing the risk of both oral cavity-localized and secondary systemic infections and for improving the overall health outcomes of individuals receiving medical treatment.

Diagnostic Value and Clinical Application of Metagenomic Next-Generation Sequencing for Infections in Critically Ill Patients

Objective

To evaluate the diagnostic value and clinical application of metagenomic next-generation sequencing (mNGS) for infections in critically ill patients.

Methods

Comparison of diagnostic performance of mNGS and conventional microbiological testing for pathogens was analyzed in 234 patients. The differences between immunocompetent and immunocompromised individuals in mNGS-guided anti-infective treatment adjustment were also analyzed.

Results

The sensitivity and specificity of mNGS for bacterial and fungal detection were 96.6% (95% confidence interval [CI], 93.5%-99.6%) and 83.1% (95% CI, 75.2%-91.1%), and 85.7% (95% CI, 71.9%-99.5%) and 93.2% (95% CI, 89.7%-96.7%), respectively. Overall, 152 viruses were detected by mNGS, but in which 28 viruses were considered causative agents. The proportion of mNGS-guided beneficial anti-infective therapy adjustments in the immunocompromised group was greater than in the immunocompetent group (48.5% vs 30.1%; P=0.008). In addition, mNGS-guided anti-infective regimens with peripheral blood and BALF specimens had the highest proportion (39.0%; 40.0%), but the proportion of patients not helpful due to peripheral blood mNGS was also as high as 22.0%.

Conclusion

mNGS might be a promising technology to provide precision medicine for critically ill patients with infection.

Description of the colonizing mycobiota of endotracheal tubes from patients admitted to two intensive care units in Bogotá, Colombia

Introduction. Medical device colonization by pathogenic microorganisms is a risk factor for increasing infections associated with health care and, consequently, the morbidity and mortality of intubated patients. In Colombia, fungal colonization of endotracheal tubes has not been described, and this information could lead to new therapeutic options for the benefit of patients. Objective. To describe the colonizing fungi of the endotracheal tubes from patients in the intensive care unit, along with its antifungal sensitivity profile. Materials and methods. We conducted a descriptive, observational study in two health centers for 12 months. Endotracheal tubes were collected from patients in intensive care units. Samples were processed for culture, fungi identification, and antifungal sensitivity profile assessment. Results. A total of 121 endotracheal tubes, obtained from 113 patients, were analyzed: 41.32 % of the tubes were colonized by Candida albicans (64.62%), C. non‑albicans (30.77%), Cryptococcus spp. (3.08%) or molds (1.54%). All fungi evaluated showed a high sensitivity to antifungals, with a mean of 91%. Conclusion. Fungal colonization was found in the endotracheal tubes of patients under invasive mechanical ventilation. The antifungal sensitivity profile in these patients was favorable. A clinical study is required to find possible correlations between the colonizing microorganisms and infectivity.

Fungal Infections Identified with Multiplex PCR in Severe COVID-19 Patients during Six Pandemic Waves

Background and Objectives: With an increasing number of severe COVID-19 cases presenting with secondary fungal infections, this study aimed to determine the prevalence of fungal co-infections in severe COVID-19 patients across the six waves, identify the most common fungal pathogens associated with severe COVID-19, and explore any potential links between patient characteristics, therapeutic strategies, and the prevalence and type of fungal infection. Materials and Methods: A retrospective analysis was conducted on severe COVID-19 patients admitted to the Infectious Diseases and Pulmonology Hospital, "Victor Babes", Romania, between March 2020 and August 2022. Samples were collected from respiratory specimens, blood, and urine, after which a standard nucleic acid extraction protocol was employed. Patients were divided into groups with and without fungal infections, identified using multiplex PCR. The groups were compared based on demographic data, comorbidities, pandemic wave number, and clinical outcomes. Results: Out of 288 patients, 96 (33.3%) had fungal infections, with Candida spp. being the most common. Patients with fungal infections had higher rates of obesity (35.4% vs. 21.4%, p = 0.010) and a higher Charlson comorbidity index (CCI > 2) (37.5% vs 25.0%, p = 0.027). Ventilator use was significantly higher in the fungal infection group (45.8% vs. 18.8%; p < 0.001), as was ICU admission (39.6% vs. 26.6%; p = 0.024) and mortality (32.3% vs 12.0%; p < 0.001). The distribution of different fungal species varied across the pandemic waves, with no statistical significance (p = 0.209). The mortality risk notably increased with the degree of drug resistance (OR for three or more drug resistances = 6.71, p < 0.001). The second, fourth, and fifth pandemic waves were significantly associated with higher mortality risk (OR = 3.72, 3.61, and 4.08, respectively, all p < 0.001). Aspergillus spp. and Mucor spp. infections were significantly associated with increased mortality risk (OR = 4.61 and 6.08, respectively, both p < 0.001). Conclusions: Our study indicates a significant presence of fungal co-infections among severe COVID-19 patients that is associated with increased morbidity and mortality, particularly in patients with drug-resistant infections. These findings underline the necessity for comprehensive diagnostic approaches and tailored treatment strategies in managing COVID-19 patients, especially during specific pandemic waves and in patients with particular fungal infections. Further research is required to understand the implications of these co-infections and their management.

Exploring the complex relationship between the lung microbiome and ventilator-associated pneumonia

INTRODUCTION

Understanding the presence and function of a diverse lung microbiome in acute lung infections, particularly ventilator-associated pneumonia (VAP), is still limited, evidencing significant gaps in our knowledge.

AREAS COVERED

In this comprehensive narrative review, we aim to elucidate the contribution of the respiratory microbiome in the development of VAP by examining the current knowledge on the interactions among microorganisms. By exploring these intricate connections, we endeavor to enhance our understanding of the disease's pathophysiology and pave the way for novel ideas and interventions in studying the respiratory tract microbiome.

EXPERT OPINION

The conventional perception of lungs as sterile is deprecated since it is currently recognized the existence of a diverse microbial community within them. However, despite extensive research on the role of the respiratory microbiome in healthy lungs, respiratory chronic diseases and acute lung infections such as pneumonia are not fully understood. It is crucial to investigate further the relationship between the pathophysiology of VAP and the pulmonary microbiome, elucidating the mechanisms underlying the interactions between the microbiome, host immune response and mechanical ventilation for the development of VAP.

Respiratory Fungal Communities are Associated with Systemic Inflammation and Predict Survival in Patients with Acute Respiratory Failure

Rationale

Disruption of respiratory bacterial communities predicts poor clinical outcomes in critical illness; however, the role of respiratory fungal communities (mycobiome) is poorly understood.

Objectives

We investigated whether mycobiota variation in the respiratory tract is associated with host-response and clinical outcomes in critically ill patients.

Methods

To characterize the upper and lower respiratory tract mycobiota, we performed rRNA gene sequencing (internal transcribed spacer) of oral swabs and endotracheal aspirates (ETA) from 316 mechanically-ventilated patients. We examined associations of mycobiome profiles (diversity and composition) with clinical variables, host-response biomarkers, and outcomes.

Measurements and Main Results

ETA samples with >50% relative abundance for C. albicans (51%) were associated with elevated plasma IL-8 and pentraxin-3 (p=0.05), longer time-to-liberation from mechanical ventilation (p=0.04) and worse 30-day survival (adjusted hazards ratio (adjHR): 1.96 [1.04-3.81], p=0.05). Using unsupervised clustering, we derived two clusters in ETA samples, with Cluster 2 (39%) showing lower alpha diversity (p<0.001) and higher abundance of C. albicans (p<0.001). Cluster 2 was significantly associated with the prognostically adverse hyperinflammatory subphenotype (odds ratio 2.07 [1.03-4.18], p=0.04) and predicted worse survival (adjHR: 1.81 [1.03-3.19], p=0.03). C. albicans abundance in oral swabs was also associated with the hyperinflammatory subphenotype and mortality.

Conclusions

Variation in respiratory mycobiota was significantly associated with systemic inflammation and clinical outcomes. C. albicans abundance emerged as a negative predictor in both the upper and lower respiratory tract. The lung mycobiome may play an important role in the biological and clinical heterogeneity among critically ill patients and represent a potential therapeutic target for lung injury in critical illness.

COLONIZATION AND AZOLE RESISTANCE OF OROPHARYNGEAL CANDIDA FUNGI IN INTENSIVE CARE PATIENTS WITH COVID-19

Patients with COVID-19 are susceptible to developing oropharyngeal candidiasis and invasive candidiasis. Invasive fungal infections can complicate the clinical course of COVID-19 and are associated with a substantially increased mortality. An important reason for the successful treatment of candidiasis is to determine the sensitivity of clinical fungal isolates to antimycotics. A microbiological study of oropharyngeal swabs was performed in 54 patients aged 33 to 94 years (mean age 67.4 years) with severe and extremely severe COVID-19, who were treated in the intensive care unit at the height of clinical manifestations. Most patients (95%) had comorbidities: hypertension (68.5%), diabetes mellitus (24%), coronary artery disease (22.2%), chronic heart failure (38.9%), obesity (23.8%), cardiac arrhythmias (20.4%), chronic cerebral ischemia (56.1%), varicose veins of the lower extremities (5.5%), chronic kidney disease (20.4%), liver cirrhosis (5.5%), HIV infection (5.5%). A comparative analysis of oropharyngeal microbial biocenosis showed differences in the frequency of occurrence of opportunistic microbial species, as well as in the number of members in microbial associations. Polyspecific fungal-bacterial associations were more common and dominated polyspecific bacterial associations. According to the results, a high frequency of oropharyngeal colonization in patients with severe COVID-19 by strains of fungi of the genus Candida was established. The vast majority of strains of fungi of the genus Candida (85.2%) were resistant to antimycotics of the azole group. A high frequency (85.2%) of oropharyngeal colonization in resuscitation patients with azole-resistant strains of fungi of the genus Candida was revealed. C. albicans dominated among Candida. C. albicans was isolated in 37 (68.5%) patients, C. pararapsilosis - in 6 (11.1%), C. tropicalis - in 3 (5.5%), C. krusei - in 2 (3.7%) %), C. kefyr - in 1 (1.9%), C. glabrata - in 1 (1.9%) patient. In 11 (20.4%) patients, associations of C. albicans and other Candida species were identified. The level of fungi in the material was etiologically significant (104 105 CFU/tamp.) in 80% of patients. The vast majority of strains (more than 70%) were resistant to fluconazole and voriconazole, which should be taken into account when prescribing candidiasis therapy in patients with COVID-19. The MIC for fluconazole against C. albicans strains was 1024 g/ml for 4 isolates, 512 g/ml for 7 isolates, and 128 g/ml for 15 isolates. The maximum MIC values ​​for voriconazole against C. albicans was 256 g/ml.

COVID-19 Is a Confounder of Increased Candida Airway Colonisation

An increased incidence of invasive fungal infection was reported in SARS-CoV-2-infected patients hospitalised in the intensive care unit. However, the impact of COVID-19 on Candida airway colonisation has not yet been assessed. This study aimed to test the impact of several factors on Candida airway colonisation, including SARS-CoV-2 infection. We conducted a two-pronged monocentric retrospective study. First, we analysed the prevalence of positive yeast culture in respiratory samples obtained from 23 departments of the University Hospital of Marseille between 1 January 2018 and 31 March 2022. We then conducted a case-control study, comparing patients with documented Candida airway colonisation to two control groups. We observed an increase in the prevalence of yeast isolation over the study period. The case-control study included 300 patients. In the multivariate logistic regression, diabetes, mechanical ventilation, length of stay in the hospital, invasive fungal disease, and the use of antibacterials were independently associated with Candida airway colonisation. The association of SARS-CoV-2 infection with an increased risk of Candida airway colonisation is likely to be a consequence of confounding factors. Nevertheless, we found the length of stay in the hospital, mechanical ventilation, diabetes, and the use of antibacterials to be statistically significant independent risk factors of Candida airway colonisation.

Risk Factors for Candida Infection among Children Admitted to a Pediatric Intensive Care Unit in a Tertiary Care Centre in Southern India

Background

To describe the clinical profile, risk factors, and outcomes that are associated with candida infection among critically ill children.

Patients and methods

A retrospective case-control study wherein 109 children admitted to the pediatric intensive care unit (PICU) in the years between 2015 and 2017 with the growth of candida from blood, urine, endotracheal (ET) aspirate, and pus swabs were included and compared to 97 age and sex-matched controls chosen from the same time period.

Results

Of the 124 candida isolates from 109 children, 37% were from blood, 24% from urine, and 14% in pus; 40% of the isolates were from ET aspirate. Candida non-albicans types (70%) predominated with Candida tropicalis causing 50% of the infections. Risk factors for candida infection were neutropenia [OR 20.01, 95% CI (0.94–422.32)], mechanical ventilation [OR 5.97, 95% CI (2.44–14.62)], peritoneal dialysis [OR 5.81, 95% CI (1.27–26.50)], institution of amino acids [OR 5.41, 95% CI (0.85–34.13)], presence of central venous catheter [OR 3.83, 95% CI (1.59–9.19)], antibiotic use >5 days [OR 3.58, 95% CI (1.38–9.29)]. Candida Cases (95.4%) had a septic shock with acute kidney injury in 34% and had significantly lower survival than controls [72 (66%) of 109 vs. 74 (80%) of 92] (p = 0.023).

Conclusions

The rate of candida infection in our PICU was 4.2% of PICU admissions. The most common species was C. tropicalis. The independent risk factors for candida infection were neutropenia, antibiotic duration >5 days, peritoneal dialysis, amino acid administration, mechanical ventilation, and presence of a central venous catheter (CVC).

How to cite this article

Rajeshwari R, Vyasam S, Chandran J, Porwal S, Ebenezer K, Thokchom M, et al. Risk Factors for Candida Infection among Children Admitted to a Pediatric Intensive Care Unit in a Tertiary Care Centre in Southern India. Indian J Crit Care Med 2022;26(6):717–722.

Clinical Implication of Candida Score in Multidrug-Resistant Pneumonia with Airway Candida Colonization

Background

The growth of Candida in respiratory secretions is usually considered colonization, and antifungal therapy is rarely required. The role of Candida colonization in the progression of bacterial pneumonia remains controversial. The aim of this study was to identify the clinical implication of Candida score by analyzinge the relationship with multidrug-resistant (MDR) pneumonia and prognosis in patients with airway Candida colonization.

Materials and Methods

This study was a retrospective review of patients with airway Candida colonization by bronchial washing or bronchoalveolar lavage. The Candida score was calculated according to the four factors (severe sepsis, surgery at baseline, total parenteral nutrition, and multifocal Candida colonization). Pneumonia related mortality or hopeless discharge expecting death was defined as a poor outcome.

Results

A total of 148 patients were enrolled in the study. In a multivariate analysis model, Candida score was identified as an independent predictor of poor outcomes (odds ratio 2.23; 95% confidential interval 1.57 – 3.17; P <0.001) in pneumonia patients with airway Candida colonization. With a Candida score of three or higher compared with low score group, it was associated with bacterial pneumonia, especially methicillin-resistant Staphylococcus aureus (MRSA) infection (0.0% vs. 15.2%, P = 0.004). In addition, patients with a high Candida score had a longer hospital stay (13 vs. 38 days, P <0.001), longer duration of intensive care (7 vs. 18 days, P <0.001), and higher pneumonia-related mortality (0.0% vs. 45.5%, P <0.001) as compared to the low Candida score group. The Candida score showed a positive correlation with other pneumonia severity scales such as CURB-65 (Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65 years) (r = 0.461, P <0.001), Pneumonia Severity Index (r = 0.397, P <0.001), and predisposition, insult, response, and organ dysfunction (PIRO) score (r = 0.425, P <0.001).

Conclusion

This study revealed that Candida is no longer a bystander of airway colonization, and that it affects the progression of bacterial pneumonia, including multidrug-resistant pathogens, particularly MRSA infection. Also Candida score can be used to predict the prognosis of patients with pneumonia.

Candida Pneumonia: An Innocent Bystander or a Silent Killer?

Invasive candidiasis is predominantly seen in immunosuppressed patients and carries a significant mortality. The clinical spectrum of invasive candidiasis encompasses candidemia and disseminated infection (intra-abdominal abscess, osteomyelitis, endophthalmitis, and Candida meningitis). The existence of Candida pneumonia has been largely debated over the years due to its rarity and presence of frequent colonization. Demonstration of Candida species by lung biopsy along with evidence of inflammation is the only way to confirm this entity. The interpretation of Candida in respiratory specimens and the decision to initiate antifungal therapy is controversial due to the lack of clinical evidence. In this mini-review, we discuss the currently available clinical data from the literature on Candida pneumonia and future perspectives regarding the need for antifungal therapy in such patients.

Plasma 1,3-β-d-glucan levels predict adverse clinical outcomes in critical illness

BACKGROUNDThe fungal cell wall constituent 1,3-β-d-glucan (BDG) is a pathogen-associated molecular pattern that can stimulate innate immunity. We hypothesized that BDG from colonizing fungi in critically ill patients may translocate into the systemic circulation and be associated with host inflammation and outcomes.METHODSWe enrolled 453 mechanically ventilated patients with acute respiratory failure (ARF) without invasive fungal infection and measured BDG, innate immunity, and epithelial permeability biomarkers in serially collected plasma samples.RESULTSCompared with healthy controls, patients with ARF had significantly higher BDG levels (median [IQR], 26 pg/mL [15-49 pg/mL], P < 0.001), whereas patients with ARF with high BDG levels (≥40 pg/mL, 31%) had higher odds for assignment to the prognostically adverse hyperinflammatory subphenotype (OR [CI], 2.88 [1.83-4.54], P < 0.001). Baseline BDG levels were predictive of fewer ventilator-free days and worse 30-day survival (adjusted P < 0.05). Integrative analyses of fungal colonization and epithelial barrier disruption suggested that BDG may translocate from either the lung or gut compartment. We validated the associations between plasma BDG and host inflammatory responses in 97 hospitalized patients with COVID-19.CONCLUSIONBDG measurements offered prognostic information in critically ill patients without fungal infections. Further research in the mechanisms of translocation and innate immunity recognition and stimulation may offer new therapeutic opportunities in critical illness.FUNDINGUniversity of Pittsburgh Clinical and Translational Science Institute, COVID-19 Pilot Award and NIH grants (K23 HL139987, U01 HL098962, P01 HL114453, R01 HL097376, K24 HL123342, U01 HL137159, R01 LM012087, K08HK144820, F32 HL142172, K23 GM122069).

Oral Candidiasis and COVID-19 in Users of Removable Dentures: Is Special Oral Care Needed?

Elderly patients with systemic disorders and immunocompromised patients seem to have a higher risk of developing morbidity from COVID-19. Candida albicans (C. albicans) is a potentially dangerous pathogen for these patients, especially for denture wearers with prosthetic stomatitis who require mechanical ventilation. C. albicans infection, the main candidiasis infection associated with denture wear, can complicate COVID-19 and increase the associated morbidity and mortality. Therefore, early diagnosis of C. albicans infection in COVID-19 patients is important to establish more effective antifungal treatment methods and prophylaxis strategies. Hospitalized COVID-19 patients should undergo an oral examination to assess their oral health, and those with poor oral health should receive the appropriate care and monitoring.

Respiratory Candida in Patients with Bronchitis, Mucus Plugging, and Atelectasis

Background

The significance of Candida in pulmonary secretions is unclear, and usually is regarded as colonization, not contributing to symptoms or disease. Yet, in our experience, Candida seemed associated with chronic sputum, mucus plugging, atelectasis, and poor outcome.

Objective

The aim of this study is to describe the clinical findings of patients with Candida in pulmonary (sputum or bronchoscopy) secretions and the significance of Candida.

Methods

Retrospective study of inpatients and outpatients referred for pulmonary consultation with Candida in pulmonary secretions. Clinical parameters and estimates of whether Candida was likely clinically significant, were determined.

Results

82 inpatients and 11 outpatients were identified, of which 61 (66%) had atelectasis and 68 (73%) bronchoscopies. Of patients having bronchoscopies, 56 (82%) had mucus, and 43 (63%) mucus plugging. Of the inpatients death (or probable death) occurred in 43 (63%), 42 (98%) of which were from definite or probable respiratory failure, with 13 (31%) likely related to mucus plugging, 16 (38%) possibly from mucus plugging, 6 (14%) unknown, and 7 (17%) not due to mucus plugging. Candida was felt likely clinically significant in 57 patients (61%), uncertain significance in 23 (25%), and not significant in 13 (14%). All outpatients had exacerbations, including 7 (64%) within a year.

Conclusion

Patients requiring pulmonary consultation with Candida in pulmonary secretions often have chronic sputum production, exacerbations, mucus plugging, atelectasis, and death from respiratory failure. Candida was likely clinically significant in most patients. Recommendations to consider Candida in pulmonary secretions as colonization should be reconsidered.

Diagnostic Value of Metagenomic Next-Generation Sequencing for the Detection of Pathogens in Bronchoalveolar Lavage Fluid in Ventilator-Associated Pneumonia Patients

Objective: To evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) in patients with ventilator-associated pneumonia (VAP).

Methods: BALF samples of 72 patients with VAP were collected from August 2018 to May 2020. The diagnostic performance of conventional testing (CT) and mNGS methods were compared based on bacterial and fungal examinations. The diagnostic value of mNGS for viral and mixed infections was also analyzed.

Results: The percentage of mNGS positive samples was significantly higher than that estimated by the CT method [odds ratio (OR), 4.33; 95% confidence interval (CI), 1.78–10.53; p < 0.001]. The sensitivity and specificity of mNGS for bacterial detection were 97.1% (95% CI, 93.2–101.0%) and 42.1% (95 CI, 30.7–53.5%), respectively, whereas the positive predictive value (PPV) and the negative predictive value (NPV) were 60.0% (95% CI, 48.7–71.3%) and 94.1% (95% CI, 88.7–99.6%), respectively. A total of 38 samples were negative for bacterial detection as determined by the CT method, while 22 samples were positive as shown by the mNGS method. Conflicting results were obtained for three samples between the two methods of bacterial detection. However, no significant differences were noted between the mNGS and CT methods (OR, 1.42; 95% CI, 0.68–2.97; p = 0.46) with regard to fungal infections. The sensitivity and specificity of mNGS were 71.9% (95% CI, 61.5–82.3%) and 77.5% (95% CI, 67.9–87.1%), respectively. mNGS exhibited a PPV of 71.9% (95% CI, 61.5–82.3%) and an NPV of 77.5% (95% CI, 67.9–87.1%). A total of 9 out of 40 samples were found positive for fungi according to mNGS, whereas the CT method failed to present positive results in these samples. The mNGS and CT methods produced conflicting results with regard to fungal detection of the two samples. A total of 30 patients were virus-positive using mNGS. Furthermore, 42 patients (58.3%) were identified as pulmonary mixed infection cases.

Conclusions: mNGS detection using BALF improved the sensitivity and specificity of bacterial identification in patients who developed VAP. In addition, mNGS exhibited apparent advantages in detecting viruses and identifying mixed infections.

The impact of Candida spp airway colonization on clinical outcomes in patients with ventilator-associated pneumonia: A systematic review and meta-analysis

BACKGROUND

Previous studies have drawn different conclusions about the impact of Candida airway colonization on clinical outcomes in patients with ventilator-associated pneumonia (VAP).

METHODS

We searched PubMed, the Cochrane Library, Embase (via OVID), and Web of Science database. We included both retrospective and prospective observational studies. The mean difference (MD) or risk ratio (RR) with 95% confidence intervals (CI) were applied to assess the association between Candida colonization and clinical outcomes.

RESULTS

A total of 8 studies with 1,661 patients were pooled in our final studies. Compared with patients with VAP without Candida colonization, patients with Candida colonization had significantly longer durations of mechanical ventilation (MD, 1.93; 95% CI, 0.53-3.33). The intensive care unit (ICU) length of stay seems to be longer among Candida colonized patients than noncolonized patients, although the results were not so significant (MD, 1.15; 95% CI, -1.04 to 3.34). Patients with colonization had higher 28-day mortality and ICU mortality than those without colonization (28-day mortality: RR, 1.64; 95% CI, 1.27-2.12; ICU mortality: RR, 1.57; 95% CI, 1.26-1.94).

CONCLUSIONS

The presence of Candida spp airway colonization is associated with longer durations of mechanical ventilation, higher 28-day mortality, higher ICU mortality, and probably longer ICU length of stay compared with the absence of colonization in patients with VAP.

Ventilator-associated pneumonia in adults: a narrative review

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections. Reported incidences vary widely from 5 to 40% depending on the setting and diagnostic criteria. VAP is associated with prolonged duration of mechanical ventilation and ICU stay. The estimated attributable mortality of VAP is around 10%, with higher mortality rates in surgical ICU patients and in patients with mid-range severity scores at admission. Microbiological confirmation of infection is strongly encouraged. Which sampling method to use is still a matter of controversy. Emerging microbiological tools will likely modify our routine approach to diagnosing and treating VAP in the next future. Prevention of VAP is based on minimizing the exposure to mechanical ventilation and encouraging early liberation. Bundles that combine multiple prevention strategies may improve outcomes, but large randomized trials are needed to confirm this. Treatment should be limited to 7 days in the vast majority of the cases. Patients should be reassessed daily to confirm ongoing suspicion of disease, antibiotics should be narrowed as soon as antibiotic susceptibility results are available, and clinicians should consider stopping antibiotics if cultures are negative.

Safety and Outcomes of Early Enteral Nutrition in Circulatory Shock

Circulatory shock is one of the most common reasons for an intensive care unit admission, has been shown to impair gut barrier and immune functions, and promotes dysbiosis. The exact timing and dose of enteral nutrition (EN) in circulatory shock remains unclear. In fact, because of fear of complications such as nonocclusive mesenteric ischemia and bowel necrosis and splanchnic steal phenomenon, clinicians may hesitate to start EN in critically ill patients with circulatory shock. In this narrative review, we identify and appraise contemporary evidence evaluating the safety and outcomes of EN in circulatory shock.

Microbial Etiology and Prognostic Factors of Ventilator-associated Pneumonia: A Multicenter Retrospective Study in Shanghai

Background

The microbial etiology and mortality risk factors of ventilator-associated pneumonia (VAP) have not been investigated extensively in Shanghai.

Methods

VAP cases were identified from the patients hospitalized during the period from 1 January 2013 to 30 December 2017 in Shanghai. The relevant data were reviewed and analyzed retrospectively.

Results

One hundred ninety-four VAP cases were included in this analysis. The overall mortality rate was 32.47%. The respiratory pathogens isolated from these patients included 212 bacterial strains and 54 fungal strains. The leading pathogens were Acinetobacter baumannii (33.96%), Klebsiella pneumoniae (23.58%), Pseudomonas aeruginosa (19.81%), and Staphylococcus aureus (7.08%). Candida colonization was associated with higher mortality of VAP patients compared to those without Candida colonization (45.45% vs 28.67%, P < .05). The VAP patients with Candida colonization also showed higher prevalence of P. aeruginosa, carbapenem-resistant P. aeruginosa (CRPA), K. pneumoniae, carbapenem-resistant K. pneumoniae (CRKP), A. baumannii, and carbapenem-resistant A. baumannii (CRAB) (P < .05). VAP nonsurvivors had higher prevalence of CRPA, K. pneumoniae, CRAB, and Candida than VAP survivors (P < .05). Multivariate analysis showed that prior antibiotic use was a significant risk factor for Candida colonization, while hypertension and length of hospital stay were significant risk factors of VAP mortality (P < .05).

Conclusions

The top pathogens of VAP patients in Shanghai tertiary teaching hospitals are A. baumannii, K. pneumoniae, and P. aeruginosa, with high prevalence of carbapenem resistance. Carbapenem-resistant bacterial pathogens and Candida may predict poor outcome.

Phase 3 Pilot Randomized Controlled Trial Comparing Early Trophic Enteral Nutrition With "No Enteral Nutrition" in Mechanically Ventilated Patients With Septic Shock

BACKGROUND

The optimal dose and timing of enteral nutrition (EN) in septic shock are unclear.

METHODS

We conducted a phase 3 single-center randomized controlled pilot trial comparing early trophic EN with "no EN" in mechanically ventilated adults with septic shock, with the hypothesis that implementing a protocol comparing early trophic EN with "no EN" in patients with septic shock would be feasible. Patients were randomized to early trophic EN or "no EN" until off vasopressor for 3 hours. The primary outcome was feasibility in achieving >75% consent and compliance rate and <10% contamination rate.

RESULTS

One hundred thirty-one patients were eligible for enrollment, and 49 were available for consent. Thirty-one (86%) consented and were randomized and 100% of patients in the early EN arm and 94% in the "no EN" arm completed their protocols. While on vasopressors, early EN group received median 384 kcal, and the "no EN" group received median 0 kcal. Contamination rate was 0 in the early trophic EN arm and 6% in the "no EN" arm. The early EN group had median 25 intensive care unit-free days, as compared with 12 in the "no EN" arm (P = .014). The early EN arm had median 27 ventilator-free days, compared with 14 in "no EN" arm (P = .009).

CONCLUSION

Our protocol comparing early trophic EN with "no EN" in septic shock was feasible. Early trophic EN may be beneficial, but a larger multicenter trial is warranted to confirm the observed clinical benefits seen in this trial.

Beyond Antagonism: The Interaction Between Candida Species and Pseudomonas aeruginosa

There are many examples of the interaction between prokaryotes and eukaryotes. One such example is the polymicrobial colonization/infection by the various opportunistic pathogenic yeasts belonging to the genus Candida and the ubiquitous bacterium, Pseudomonas aeruginosa. Although this interaction has simplistically been characterized as antagonistic to the yeast, this review highlights the complexity of the interaction with various factors influencing both microbes. The first section deals with the interactions in vitro, looking specifically at the role of cell wall components, quorum sensing molecules, phenazines, fatty acid metabolites and competition for iron in the interaction. The second part of this review places all these interactions in the context of various infection or colonization sites, i.e., lungs, wounds, and the gastrointestinal tract. Here we see that the role of the host, as well as the methodology used to establish co-infection, are important factors, influencing the outcome of the disease. Suggested future perspectives for the study of this interaction include determining the influence of newly identified participants of the QS network of P. aeruginosa, oxylipin production by both species, as well as the genetic and phenotypic plasticity of these microbes, on the interaction and outcome of co-infection.

Respiratory Tract Colonization by Candida species Portends Worse Outcomes in Immunocompromised Patients

Background

The significance and clinical management of Candida colonization of the respiratory tract are ill-defined. We now report the frequency of Candida species from the lower respiratory tract in hematopoietic stem cell transplant recipients (HSCT) undergoing bronchoscopy with broncheoalveolar lavage (BAL) for pneumonitis post-HSCT.

Methods

The University of Michigan Clinical Microbiology Lab Database was queried for all respiratory cultures positive for Candida species between 2000-2012. We concurrently performed a retrospective analysis of 515 HSCT recipients with pneumonitis at our institution between 2001-2012.

Results

During this twelve-year period, there were 2524 unique Candida isolates (78% Candida albicans). Of the 515 HSCT patients with suspected pneumonitis,127 (24.7%) HSCT subjects were culture positive for a fungal pathogen, with Candida species identified in 27 cases (5.2%). When compared with other HSCT subjects, those cultures positive for Candida had significantly increased mortality (p=0.04).

Conclusions

Candida sp. are commonly cultured from the respiratory tract of HSCT recipients, with increased mortality in affected patients. While there is insufficient evidence for anti-fungal treatment of Candida species colonization, the presence of the yeast may be useful as a surrogate marker of disease severity.

The significance of Candida in the human respiratory tract: our evolving understanding

Candida is an opportunistic pathogen and the most commonly isolated fungal genus in humans. Though Candida is often detected in respiratory specimens from humans with and without lung disease, its significance remains undetermined. While historically considered a commensal organism with low virulence potential, the status of Candida as an innocent bystander has recently been called into question by both clinical observations and animal experimentation. We here review what is currently known and yet to be determined about the clinical, microbiological and pathophysiological significance of the detection of Candida spp. in the human respiratory tract.

Measuring (1,3)-β-D-glucan in tracheal aspirate, bronchoalveolar lavage fluid, and serum for detection of suspected Candida pneumonia in immunocompromised and critically ill patients: a prospective observational study

Background

While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-β-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients.

Methods

This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay.

Results

After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia.

Conclusions

D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2364-2) contains supplementary material, which is available to authorized users.

Candida Species Biofilms' Antifungal Resistance

Candida infections (candidiasis) are the most prevalent opportunistic fungal infection on humans and, as such, a major public health problem. In recent decades, candidiasis has been associated to Candida species other than Candida albicans. Moreover, biofilms have been considered the most prevalent growth form of Candida cells and a strong causative agent of the intensification of antifungal resistance. As yet, no specific resistance factor has been identified as the sole responsible for the increased recalcitrance to antifungal agents exhibited by biofilms. Instead, biofilm antifungal resistance is a complex multifactorial phenomenon, which still remains to be fully elucidated and understood. The different mechanisms, which may be responsible for the intrinsic resistance of Candida species biofilms, include the high density of cells within the biofilm, the growth and nutrient limitation, the effects of the biofilm matrix, the presence of persister cells, the antifungal resistance gene expression and the increase of sterols on the membrane of biofilm cells. Thus, this review intends to provide information on the recent advances about Candida species biofilm antifungal resistance and its implication on intensification of the candidiasis.

Characteristics, Clinical Relevance, and the Role of Echinocandins in Fungal-Bacterial Interactions

Fungal-bacterial interactions are common in the environment. The interactions between invasive fungi (eg, Candida species and Aspergillus species) and pathogenic bacteria can be particularly significant in the outcome of human infections. Study of these interactions in vivo using murine or invertebrate models, such as Caenorhabditis elegans or Galleria mellonella, has been very helpful in increasing our understanding of the pathogenesis of mixed infections and in identifying ways to use this between-kingdom interplay to our advantage. Based on their effect against fungal biofilms and their immunomodulatory properties, the newer class of antifungal agents, known as echinocandins, has the potential to be useful in polymicrobial infections and in high-risk complex infections such as ventilator-associated pneumonia or sepsis where colonization by fungi can lead to worse outcomes.

Characterisation of Candida within the Mycobiome/Microbiome of the Lower Respiratory Tract of ICU Patients

Whether the presence of Candida spp. in lower respiratory tract (LRT) secretions is a marker of underlying disease, intensive care unit (ICU) treatment and antibiotic therapy or contributes to poor clinical outcome is unclear. We investigated healthy controls, patients with proposed risk factors for Candida growth in LRT (antibiotic therapy, ICU treatment with and without antibiotic therapy), ICU patients with pneumonia and antibiotic therapy and candidemic patients (for comparison of truly invasive and colonizing Candida spp.). Fungal patterns were determined by conventional culture based microbiology combined with molecular approaches (next generation sequencing, multilocus sequence typing) for description of fungal and concommitant bacterial microbiota in LRT, and host and fungal biomarkes were investigated. Admission to and treatment on ICUs shifted LRT fungal microbiota to Candida spp. dominated fungal profiles but antibiotic therapy did not. Compared to controls, Candida was part of fungal microbiota in LRT of ICU patients without pneumonia with and without antibiotic therapy (63% and 50% of total fungal genera) and of ICU patients with pneumonia with antibiotic therapy (73%) (p<0.05). No case of invasive candidiasis originating from Candida in the LRT was detected. There was no common bacterial microbiota profile associated or dissociated with Candida spp. in LRT. Colonizing and invasive Candida strains (from candidemic patients) did not match to certain clades withdrawing the presence of a particular pathogenic and invasive clade. The presence of Candida spp. in the LRT rather reflected rapidly occurring LRT dysbiosis driven by ICU related factors than was associated with invasive candidiasis.

The clinical importance of fungal biofilms

Fungal biofilms have become an increasingly important clinical problem. The widespread use of antibiotics, frequent use of indwelling medical devices, and a trend toward increased patient immunosuppression have resulted in a creation of opportunity for clinically important yeasts and molds to form biofilms. This review will discuss the diversity and importance of fungal biofilms in the context of clinical medicine, provide novel insights into the clinical management of fungal biofilm infection, present evidence why these structures are recalcitrant to antifungal therapy, and discuss how our knowledge and understanding may lead to novel therapeutic intervention.

Polymicrobial community-acquired pneumonia: An emerging entity

Polymicrobial aetiology in community-acquired pneumonia (CAP) is more common than previously recognized. This growing new entity can influence inflammation, host immunity and disease outcomes in CAP patients. However, the true incidence is complicated to determine and probably underestimated due mainly to many cases going undetected, particularly in the outpatient setting, as the diagnostic yield is restricted by the sensitivity of currently available microbiologic tests and the ability to get certain types of clinical specimens. The observed rate of polymicrobial cases may also lead to new antibiotic therapy considerations. In this review, we discuss the pathogenesis, microbial interactions in pneumonia, epidemiology, biomarkers and antibiotic therapy for polymicrobial CAP.

Impact of Candida spp. isolation in the respiratory tract in patients with intensive care unit-acquired pneumonia

In immunocompetent patients with nosocomial pneumonia, the relationship between Candida spp. isolation in respiratory samples and outcomes or association with other pathogens is controversial. We therefore compared the characteristics and outcomes of patients with intensive care unit-acquired pneumonia (ICUAP), with or without Candida spp. isolation in the respiratory tract. In this prospective non-interventional study, we assessed 385 consecutive immunocompetent patients with ICUAP, according to the presence or absence of Candida spp. in lower respiratory tract samples. Candida spp. was isolated in at least one sample in 82 (21%) patients. Patients with Candida spp. had higher severity scores and organ dysfunction at admission and at onset of pneumonia. In multivariate analysis, previous surgery, diabetes mellitus and higher Simplified Acute Physiology Score II at ICU admission independently predicted isolation of Candida spp. There were no significant differences in the rate of specific aetiological pathogens, the systemic inflammatory response, and length of stay between patients with and without Candida spp. Mortality was also similar, even adjusted for potential confounders in propensity-adjusted multivariate analyses (adjusted hazard ratio 1.08, 95% CI 0.57-2.05, p 0.80 for 28-day mortality and adjusted hazard ratio 1.38, 95% CI 0.81-2.35, p 0.24 for 90-day mortality). Antifungal therapy was more frequently prescribed in patients with Candida spp. in respiratory samples but did not influence outcomes. Candida spp. airway isolation in patients with ICUAP is associated with more initial disease severity but does not influence outcomes in these patients, regardless of the use or not of antifungal therapy.

Microbial composition and antibiotic resistance of biofilms recovered from endotracheal tubes of mechanically ventilated patients

In critically ill patients, breathing is impaired and mechanical ventilation, using an endotracheal tube (ET) connected to a ventilator, is necessary. Although mechanical ventilation is a life-saving procedure, it is not without risk. Because of several reasons, a biofilm often forms at the distal end of the ET and this biofilm is a persistent source of bacteria which can infect the lungs, causing ventilator-associated pneumonia (VAP). There is a link between the microbial flora of ET biofilms and the microorganisms involved in the onset of VAP. Culture dependent and independent techniques were already used to identify the microbial flora of ET biofilms and also, the antibiotic resistance of microorganisms obtained from ET biofilms was determined. The ESKAPE pathogens play a dominant role in the onset of VAP and these organisms were frequently identified in ET biofilms. Also, antibiotic resistant microorganisms were frequently present in ET biofilms. Members of the normal oral flora were also identified in ET biofilms but it is thought that these organisms initiate ET biofilm formation and are not directly involved in the development of VAP.

Gender differences in randomised, controlled trials in intensive care units

There is a male dominance among patients in intensive care units (ICUs). Potentially, this will increase the risk of a skewed male/female distribution in randomised, controlled trials (RCTs). We have evaluated if this has in fact happened when randomising and whether the authors have been aware of that. We performed a systematic search on PubMed from 1 January 2011 to 31 May 2012 using the mesh terms 'randomized controlled trial' and 'intensive care unit'. Twenty-five RCTs with a total of 12,788 patients met the inclusion criteria, with an overall male dominance of 63.6% (P < 0.0001). Eighteen of the 25 papers had an individually statistically significant gender difference in their total trial population. None of the 18 trials with a significant gender difference in their overall trial population had calculated the P-value for this overall difference. In the randomised groups, there was a significant gender difference in five papers. Seventeen had no significant gender difference in the randomised groups, and three papers did not state gender in the randomised groups. This study show that there is a marked male dominance in RCTs conducted in ICUs. We recommend that when planning future RCTs, the authors contemplate if their results can be used indiscriminately among ICU patients if the distribution of males and females is much skewed. It is relevant to determine if ones endpoint can be influenced by gender differences and if there is a risk of gender influence on data, proportional allocation or stratification should be considered.

Candida in the respiratory tract secretions of critically ill patients and the impact of antifungal treatment: a randomized placebo controlled pilot trial (CANTREAT study)

PURPOSE

Candida spp. are frequently recovered from endotracheal secretions in critically ill patients suspected of having ventilator-associated pneumonia. Observational studies reported an association with worse clinical outcomes but the effect of antifungal therapy in these patients remains unclear. We designed this pilot study to assess the feasibility of a larger trial and to evaluate inflammatory profiles and clinical outcomes in these patients.

METHODS

We conducted a double-blind, placebo-controlled, multicenter pilot randomized trial of antifungal therapy in critically ill patients with a clinical suspicion of ventilator-associated pneumonia with positive airway secretion specimens for Candida spp. We also included an observational group without Candida spp. in their airway secretions. We measured recruitment rate, inflammatory and innate immune function profiles over time, and clinical outcomes.

RESULTS

We recruited 60 patients into the randomized trial and 29 patients into the observational study. Markers of inflammation and all clinical outcomes were comparable between placebo and antifungal treatment group at baseline and over time. At baseline, plasma TNF-α levels were higher in patients with VAP and Candida compared to the observational group (mean ± SD) (21.8 ± 23.1 versus 12.4 ± 9.3 pg/ml, p = 0.02) and these patients had lower innate immune function as evidenced by reduced whole blood ex vivo LPS-induced TNF-α production capacity (854.8 ± 855.2 versus 1,559.4 ± 1,290.6 pg/ml, p = 0.01).

CONCLUSIONS

This study does not provide evidence to support a larger trial examining the efficacy of empiric antifungal treatment in patients with a clinical suspicion of ventilator-associated pneumonia and Candida in the endotracheal secretions. The presence of Candida in the lung may be associated with persistent inflammation and immunosuppression.

The impact of antimicrobial resistance and aging in VAP outcomes: experience from a large tertiary care center

Background

Ventilator associated pneumonia (VAP) is a serious infection among patients in the intensive care unit (ICU).

Methods

We reviewed the medical charts of all patients admitted to the adult intensive care units of the Massachusetts General Hospital that went on to develop VAP during a five year period.

Results

200 patients were included in the study of which 50 (25%) were infected with a multidrug resistant pathogen. Increased age, dialysis and late onset (≥5 days from admission) VAP were associated with increased incidence of resistance. Multidrug resistant bacteria (MDRB) isolation was associated with a significant increase in median length of ICU stay (19 vs. 16 days, p = 0.02) and prolonged duration of mechanical ventilation (18 vs. 14 days, p = 0.03), but did not impact overall mortality (HR 1.12, 95% CI 0.51–2.46, p = 0.77). However, age (HR 1.04 95% CI 1.01–1.07, p = 0.003) was an independent risk factor for mortality and age ≥65 years was associated with increased incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections (OR 2.83, 95% CI 1.27–6.32, p = 0.01).

Conclusions

MDRB-related VAP is associated with prolonged ICU stay and mechanical ventilation. Interestingly, age ≥ 65 years is associated with MRSA VAP.

Why Candida sepsis should matter to ICU physicians

The incidence of candidemia and invasive Candida infections has increased substantially over the last 2 decades. These infections are associated with risk factors that characterize intensive care unit patients. Candidemia and invasive Candida are highly morbid and associated with significantly increased mortality. Outcomes in the intensive care setting depend on physician awareness and rapid intervention. The epidemiology of the disease, its diagnostic challenges, and management strategies, including prophylactic, preemptive, and definitive therapeutic approaches, are presented herein.