Is Candida really a threat in the ICU?

Calculated parenteral initial treatment of bacterial infections: Intra-abdominal infections

This is the seventh chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter deals with the empirical and targeted antimicrobial therapy of complicated intra-abdominal infections. It includes recommendations for antibacterial and antifungal treatment.

Phenotypic and genotypic characterization of Candida species isolated from candideamia in Iran

Background and Purpose:

Candidemia is one of the most important fungal infections caused by Candida species. Infections and mortality caused by Candida species have been on a growing trend during the past two decades. The resistance of yeasts to antifungal drugs and their epidemiological issues have highlighted the importance of accurately distinguishing the yeasts at the species level. The technique applied for yeast identification should be fast enough to facilitate the imminent initiation of the appropriate therapy. Candidemia has not been studied comprehensively in Iran yet. Regarding this, the current study aimed to assess the epidemiology of candidemia at Tehran hospitals and compare the results with the previous findings.

Materials and Methods:

This study was conducted on 204 positive blood cultures obtained from 125 patients hospitalized in several hospitals located in Tehran, Iran, within a period of 13 months. The yeast isolation and species identification were accomplished using several phenotypic methods (i.e., production of germ tube in human serum, culture on CHROMagar Candida, and Corn meal agar containing Tween 80) and molecular methods, such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown cases were subjected to PCR sequencing. These methods were then compared in terms of accuracy, sensitivity, and speed of identification.

Results:

According to the results, C. albicans (62.4%) was the most common isolate, followed by C. parapsilosis (n=36, 17.5%), C. glabrata (n=18, 8.8%), C. tropicalis (n=13, 6.3%), Trichosporon asahii (n=3, 1.5%), C. kefyr (n=2, 1.0%), C. lusitaniae (n=2, 1.0%), C. intermedia (n=1, 0.5%), C. guilliermondii (n=1, 0.5%), and C. krusei (n=1, 0.5%), respectively.

Conclusion:

As the findings indicated, the most common species causing candidemia were C. albicans, C. parapsilosis, and C. glabrata, respectively. Children less than one year old and people with cancer were at higher risk for candidemia, compared to other groups. Moreover, phenotypic and molecular methods resulted in the identification of 65.2% and 96.6% of the isolates, respectively. Consequently, PCR-RFLP could be concluded as a more favorable technique for species identification.

MICROBIOLOGICAL SPECTRE OF TERTIARY PERITONITIS AS A COMPONENT OF ITS DIAGNOSTICS AND TREATMENT

The aim of the research was to investigate the microbial spectre of tertiary peritonits (TP) and its antibiotic resistance as the way to improve the diagnostics and treatment of TP. Materials and methods. Prospective research enrolled 109 patients with secondary peritonitis. Tertiary peritonitis developed in 18,3 % of cases. Samples of peritoneal exudate had been drawn upon index operation, relaparotomy and on the day of diagnosis of TP. Blood sampling was performed in patients with persistent fever, impaired consciousness, prolonged (>4 days) discharge from drainage tubes and on the 1st day of diagnosis of TP. Antibacterial susceptibility was evaluated using Hinton-Müller media. Results and discussion. Patients were divided into 2 groups: with secondary peritonitis (89) and with TP (20). In TP group, cultivation of 76,2 % of primary specimens resulted in replantable and identifiable growth, presenting a shift towards Gram-negative flora and higher incidence of Candida albicans. Following the development of TP, hemocultures were positive in 15,1 %, presented mainly by Proteus spp. and non-albicans Candida spp. Second-group carbapenems, tigecycline and piperacillin-tazobactam had shown the highest activity in pathogens of TP. Caspofungin proved to be the most potent antifungal agent, especially towards non-albicans Candida spp. Antibiotic resistance in TP group was marked in 63,8 %. Conclusions. Tertiary peritonitis is one of the most severe forms of abdominal sepsis with highest mortality. Causing pathogenic flora in case of TP is mainly Gram-negative and coccal with high rates of antibiotic resistance both in vitro and in vivo. Fungi, presented predominantly by Candida non-albicans substrains, show an increasing content in peritoneal exudate and major effect upon mortality in TP. In case of TP, a significant percent of peritoneal specimens do not provide any culture growth despite of observing stringent sampling, transportation and cultivation rules. Antimicrobial therapy of TP can never be standardized and should always be thoroughly based upon regular and proper peritoneal and blood sampling.

A high yield DNA extraction method for medically important Candida species: A comparison of manual versus QIAcube-based automated system

The prognosis of infected individuals with candidemia depends on rapid and precise diagnosis which enables optimising treatment. Three fungal DNA extraction protocols have been compared in this study for medically important Candida species. The quality and quantity of the DNA extracted by physical, chemical and automated protocols was compared using NanoDrop ND-2000 spectrophotometer. It was found that the yield and purity (260/230) ratio of extracted DNA was significantly high in the physical treatment-based protocol as compared to chemical based or automated protocol. Extracted DNA-based real time-polymerase chain reaction showed an analytical sensitivity of 103 cfu/mL. The result of this study suggests physical treatment is the most successful extraction technique compared to other two protocols.

Cost-Effectiveness Analysis of Multiplex PCR with Magnetic Resonance Detection versus Empiric or Blood Culture-Directed Therapy for Management of Suspected Candidemia

Candida bloodstream infections (BSI) are associated with significant morbidity, mortality, and increased health care costs. Early treatment is essential, because delayed therapy detrimentally impacts clinical outcomes. The FDA recently approved the first culture-independent direct molecular detection method for Candida BSIs (T2Candida). The speed and sensitivity of this assay give it the potential to improve patient care, but the reagents and instrumentation are expensive. We used an analytic decision tree model to compare the cost-effectiveness of T2Candida-directed antifungal therapy (T2DT) to that of either empirical therapy (ET) or blood culture-directed therapy (BCDT). The costs included those of T2Candida testing, antifungal treatment, and hospital length of stay. The effectiveness measure was survival status at hospital discharge. T2DT was less costly and more effective than BCDT but was less costly and less effective than ET with an echinocandin (incremental cost-effectiveness ratio, $111,084 per additional survivor). One-way sensitivity analyses demonstrated that the cost-effectiveness of T2DT was highly dependent on Candida BSI prevalence and the cost of antifungal therapy and T2Candida test reagents. The use of T2DT reduced the number of unnecessarily treated patients by 98% relative to that with ET. Reduced drug exposure might lessen the possibility of drug-related adverse events and may also prevent the development of antifungal resistance or emergence of drug-resistant Candida species. The greatest benefit of T2Candida appears to be the ability to confidently withhold or stop empirical antifungal therapy in low-to-moderate-risk patients who are unlikely to benefit from treatment.

How to treat fungal infections in ICU patients

Fungal infections represent a major burden in the critical care setting with increasing morbidity and mortality. Candidiasis is the leading cause of such infections, with C. albicans being the most common causative agent, followed by Aspergillosis and Mucormycosis. The diagnosis of such infections is cumbersome requiring increased clinical vigilance and extensive laboratory testing, including radiology, cultures, biopsies and other indirect methods. However, it is not uncommon for definitive evidence to be unavailable. Risk and host factors indicating the probability of infections may greatly help in the diagnostic approach. Timely and adequate intervention is important for their successful treatment. The available therapeutic armamentarium, although not very extensive, is effective with low resistance rates for the newer antifungal agents. However, timely and prudent use is necessary to maximize favorable outcomes.

Yeast central nervous system infection in a critically ill patient: a case report

Introduction

Invasive fungal infections are alarmingly common in intensive care unit patients; invasive fungal infections are associated with increased morbidity and mortality. Risk factors are the increased use of indwelling central venous catheters, the use of broad spectrum antibiotics, parenteral nutrition, renal replacement therapy and immunosuppression. Diagnosis of these infections might be complicated, requiring tissue cultures. In addition, therapy of invasive fungal infections might be difficult, given the rising resistance of fungi to antifungal agents.

Case presentation

We describe the case of a 28-year-old Greek man with yeast central nervous system infection.

Conclusions

Difficult-to-treat fungal infections may complicate the clinical course of critically ill patients and render their prognosis unfavorable. This report presents a case that was rare and difficult to treat, along with a thorough review of the investigation and treatment of these kinds of fungal infections in critically ill patients.

How to select an antifungal agent in critically ill patients

Fungal infections are common in critically ill patients and are associated with increased morbidity and mortality. Candida spp are the most commonly isolated fungal pathogens. The last 2 decades have seen an increased incidence of fungal infections in critical illness and the emergence of new pathogenic fungal species and also the development of more effective (better bioavailability) and safer (less toxicity, fewer drug interactions) drugs. The distinction between colonization and infection can be difficult, and problems diagnosing infection may delay initiation of antifungal treatment. A number of factors have been identified that can help to distinguish patients at high risk for fungal infection. The antifungal agents that are most frequently used in the intensive care unit are the first- and second-generation azoles and the echinocandins; amphotericin B derivatives (mainly the liposomal agents) are less widely used because of adverse effects. The choice of antifungal agent in critically ill patients will depend on the aim of therapy (prophylaxis, pre-emptive, empiric, definitive), as well as on local epidemiology and specific properties of the drug (antifungal spectrum, efficacy, toxicity, pharmacokinetic/pharmacodynamic properties, cost). In this article we will review all these aspects and propose an algorithm to guide selection of antifungal agents in critically ill patients.

An Observational Study on Early Empiric versus Culture-Directed Antifungal Therapy in Critically Ill with Intra-Abdominal Sepsis

Objective. To compare early empiric antifungal treatment with culture-directed treatment in critically ill patients with intra-abdominal sepsis. Methods. A prospective observational cohort study was conducted between August 2010 and July 2011, on SICU patients admitted after surgery for gastrointestinal perforation, bowel obstruction or ischemia, malignancy and anastomotic leakages. Patients who received antifungal treatment within two days of sepsis onset were compared to patients who received culture-directed antifungal treatment in terms of mortality rate and clinical improvement. Patients' demographics, comorbidities, severity-of-illness scores, and laboratory results were systematically collected and analysed. Results. Thirty-three patients received early empiric and 19 received culture-directed therapy. Of these, 30 from the early empiric group and 18 from culture-directed group were evaluable and analysed. Both groups had similar baseline characteristics and illness severity. Patients on empiric antifungal use had significantly lower 30-day mortality (P = 0.03) as well as shorter median time to clinical improvement (P = 0.025). Early empiric antifungal therapy was independently associated with survival beyond 30 days (OR 0.131, 95% CI: 0.018 to 0.966; P = 0.046). Conclusion. Early empiric antifungal therapy in surgical patients with intra-abdominal sepsis was associated with reduced mortality and warrants further evaluation in randomised controlled trials.

Invasive fungal infections in the ICU: how to approach, how to treat

Invasive fungal infections are a growing problem in critically ill patients and are associated with increased morbidity and mortality. Most of them are due to Candida species, especially Candida albicans. Invasive candidiasis includes candidaemia, disseminated candidiasis with deep organ involvement and chronic disseminated candidiasis. During the last decades rare pathogenic fungi, such as Aspergillus species, Zygomycetes, Fusarium species and Scedosporium have also emerged. Timely diagnosis and proper treatment are of paramount importance for a favorable outcome. Besides blood cultures, several laboratory tests have been developed in the hope of facilitating an earlier detection of infection. The antifungal armamentarium has also been expanded allowing a treatment choice tailored to individual patients' needs. The physician can choose among the old class of polyenes, the older and newer azoles and the echinocandins. Factors related to patient's clinical situation and present co-morbidities, local epidemiology data and purpose of treatment (prophylactic, pre-emptive, empiric or definitive) should be taken into account for the appropriate choice of antifungal agent.

Early diagnosis of candidemia in intensive care unit patients with sepsis: a prospective comparison of (1→3)-β-D-glucan assay, Candida score, and colonization index

Introduction

The culture-independent serum (1→3)-β-D-glucan (BG) detection test may allow early diagnosis of invasive fungal disease, but its clinical usefulness needs to be firmly established. A prospective single-center observational study was conducted to compare the diagnostic value of BG assay, Candida score (CS), and colonization index in intensive care unit (ICU) patients at risk for Candida sepsis.

Methods

Of 377 patients, consecutively admitted to ICU for sepsis, 95 patients having an ICU stay of more than five days were studied. Blood specimens for fungal culture and BG measurement were obtained at the onset of clinical sepsis. For CS and colonization index calculations, surveillance cultures for Candida growth, and/or clinical data were recorded.

Results

Sixteen (16.8%) patients were diagnosed with proven invasive fungal infection, 14 with candidiasis (13 candidemia and 1 mediastinitis) and 2 with pulmonary aspergillosis or fusariosis. Of 14 invasive Candida-infection patients, 13 had a serum sample positive for BG, 10 had a CS value ≥3, and 7 a colonization index ≥0.5. In the 12 candidemic patients, a positive BG result was obtained 24 to 72 hrs before a culture-documented diagnosis of invasive candidiasis. The positive and negative predictive values for the BG assay were higher than those of CS and colonization index (72.2% versus 57.1% and 27.3%; and 98.7% versus 97.2% and 91.7%, respectively).

Conclusions

A single-point BG assay based on a blood sample drawn at the sepsis onset, alone or in combination withCS, may guide the decision to start antifungal therapy early in patients at risk for Candida infection.

Epidemiological characteristics of Candida species colonizing oral and rectal sites of Jordanian infants

BACKGROUND

There is evidence that Candida colonization contributes to increasing invasion of candidiasis in hospitalized neonates. Few studies investigated the epidemiology and risk factors of Candida colonization among hospitalized and non-hospitalized infants. This prospective study investigated the major epidemiological characteristics of Candida species colonizing oral and rectal sites of Jordanian infants.

METHODS

Infants aged one year or less who were examined at the pediatrics outpatient clinic or hospitalized at the Jordan University Hospital, Amman, Jordan, were included in this study. Culture swabs were collected from oral and rectal sites and inoculated on Sabouraud dextrose agar. All Candida isolates were confirmed by the Remel RapID yeast plus system, and further investigated for specific virulence factors and antifungal susceptibility MIC using E-test. Genotyping of C. albicans isolates was determined using random amplified polymorphic DNA (RAPD) analysis method.

RESULTS

A total of 61/492 (12.4%) infants were colonized with Candida species by either their oral/rectal sites or both. Rectal colonization was significantly more detected than oral colonization (64.6% verses 35.4%), particularly among hospitalized infants aged more than one month. The pattern and rates of colonization were as follows: C. albicans was the commonest species isolated from both sites and accounted for 67.1% of all isolates, followed by C.kefyr (11.4%), each C. tropicalis and C. glabrata (8.9%) and C. parapsilosis (3.8%). A various rates of Candida isolates proved to secrete putative virulence factors in vitro; asparatyl proteinase, phospholipase and hemolysin. C. albicans were associated significantly (P < 0.05) with these enzymes than other Candida species. All Candida isolates were susceptible to amphotericin B and caspofungin, whereas 97% of Candida species isolates were susceptible to fluconazole using E-test. The genetic similarity of 53 C. albicans isolates as demonstrated by dendrogram revealed the presence of 29 genotypes, and of these one genotype accounted for 22% of the isolates.

CONCLUSION

This study presents important epidemiological features of Candida colonization of Jordanian infants.

Antimicrobial treatment of "complicated" intra-abdominal infections and the new IDSA guidelines ? a commentary and an alternative European approach according to clinical definitions

Recently, an update of the IDSA guidelines for the treatment of complicated intraabdominal infections has been published. No guideline can cater for all variations in ecology, antimicrobial resistance patterns, patient characteristics and presentation, health care and reimbursement systems in many different countries. In the short time the IDSA guidelines have been available, a number of practical clinical issues have been raised by physicians regarding interpretation of the guidelines. The main debatable issues of the new IDSA guidelines are described as follows: The authors of the IDSA guidelines present recommendations for the following subgroups of "complicated" IAI: community-acquired intra-abdominal infections of mild-to-moderate and high severity and health care-associated intra-abdominal infections (no general treatment recommendations, only information about antimicrobial therapy of specific resistant bacterial isolates). From a clinical point of view, "complicated" IAI are better differentiated into primary, secondary (community-acquired and postoperative) and tertiary peritonitis. Those are the clinical presentations of IAI as seen in the emergency room, the general ward and on ICU. Future antibiotic treatment studies of IAI would be more clinically relevant if they included patients in studies for the efficacy and safety of antibiotics for the treatment of the above mentioned forms of IAI, rather than conducting studies based on the vague term "complicated" intra-abdominal infections. - The new IDSA guidelines for the treatment of resistant bacteria fail to mention many of new available drugs, although clinical data for the treatment of "complicated IAI" with new substances exist. Furthermore, treatment recommendations for cIAI caused by VRE are not included. This group of diseases comprises enough patients (i.e. the entire group of postoperative and tertiary peritonitis, recurrent interventions in bile duct surgery or necrotizing pancreatitis) to provide specific recommendations for such antimicrobial treatment. - A panel of European colleagues from surgery, intensive care, clinical microbiology and infectious diseases has developed recommendations based on the above mentioned clinical entities with the aim of providing clear therapeutic recommendations for specific clinical diagnoses. An individual patient-centered approach for this very important group of diseases with a substantial morbidity and mortality is essential for optimal antimicrobial treatment.

Monitoring plasma voriconazole levels following intravenous administration in critically ill patients: an observational study

Data relating to the pharmacokinetics of voriconazole in critically ill patients are lacking. A prospective observational study was conducted on 18 non-consecutive critically ill patients aged 24-97 years, comprising 12 patients with normal renal function (NRF) [creatinine clearance (CL(Cr)) > or = 60 mL/min] and 6 patients with moderate renal impairment (MRI) (CL(Cr) 40-55 mL/min), administered voriconazole intravenously (6 mg/kg loading dose and 3-4 mg/kg twice daily thereafter) in order to determine the suitability of these doses in this patient population. Steady-state blood levels were monitored and liver and renal function were recorded throughout treatment. Large variability in patient plasma levels was observed, ranging from 37% at < or = 1 mg/L (minimum inhibitory concentration at which, for most fungal pathogens, 90% of isolates are susceptible) to 19% at >5.5mg/L. Moreover, maintaining trough concentrations above clinical breakpoints was not consistently achieved because 16/30 (53%) were < or = 1 mg/L. In a few MRI patients, average concentrations were found to be significantly different compared with those of NRF patients administered the same dose, however this difference was not noted in pharmacokinetic parameters following dose normalisation. None of the patients experienced deterioration in renal or liver function. Recommended voriconazole doses are inadequate to achieve drug concentrations >1 microg/mL over the entire dosing interval in some critically ill patients.

Rapid and direct quantification of viable Candida species in whole blood by use of immunomagnetic separation and solid-phase cytometry

Candida species are a common source of nosocomial bloodstream infections in critically ill patients. The sensitivity of the traditional diagnostic procedure based on blood culture is variable, and it usually takes 2 to 4 days before growth of Candida species is detected. We developed a 4-h method for the quantification of Candida species in blood, combining immunomagnetic separation (IMS) with solid-phase cytometry (SPC) using viability labeling. Additionally, Candida albicans cells could be identified in real time by using fluorescent in situ hybridization. By analysis of spiked blood samples, our method was shown to be sensitive and specific, with a low detection limit (1 cell/ml of blood). In a proof-of-concept study, we applied the IMS/SPC method to 16 clinical samples and compared it to traditional blood culture. Our method proved more sensitive than culture (seven samples were positive with IMS/SPC but negative with blood culture), and identification results were in agreement. The IMS/SPC data also suggest that mixed infections might occur frequently, as C. albicans and at least one other Candida species were found in five samples. Additionally, in two cases, high numbers of cells (175 to 480 cells/ml of blood) were associated with an endovascular source of infection.

Epidemiology, incidence and risk factors for invasive candidiasis in high-risk patients

Candida spp. are an increasing cause of bloodstream infections, and are associated with high morbidity and mortality in both neutropenic and non-neutropenic critically ill patients. Risk factors associated with candidaemia are diverse and include exposure to broad spectrum antimicrobial agents, mucosal colonization by Candida spp., indwelling vascular catheters, prior surgery and cancer chemotherapy. During the last 20 years, there has been an increasing incidence worldwide in invasive candidiasis, but differences in geographical epidemiology are emerging, in particular regarding a shift towards non-albicans species. This shift has been correlated with routine fluconazole prophylaxis adopted in some patients, and the intrinsic/acquired azole resistance of Candida spp., which represents a very real problem, in terms of both selecting the appropriate empirical therapeutic approach and making prophylactic choices.

Candida isolation in patients hospitalized on a surgical ward: significance and mortality-related factors

BACKGROUND

Infections caused by Candida are an emerging pathology on surgical wards. The aim of the present study was to evaluate the incidence, characteristics, and predictive factors of mortality in patients colonized and/or infected by Candida spp. in this setting.

METHODS

A consecutive series of 105 patients hospitalized on a general surgery ward between 2000 and 2004 were included, and 118 positive cultures for Candida were identified. The variables age, sex, previous medical history, current disease, anemia, ICU stay, type and localization of the microorganism, need for parenteral nutrition, and transfusions were recorded. The primary outcome was in-hospital mortality. A univariate analysis was performed to determine which of these variables were associated with mortality. With a logistic regression model, independent prognostic factors of mortality were determined.

RESULTS

The prevalence of patients colonized and/or infected by Candida on our surgical ward was 0.98% (CI 95%: 0.79-1.17), and the incidence was 49 cases per 1,000 patient-years. Of the 105 patients in this series, 56 were men (53%) and 49 women (47%); the mean age was 63.8 years (SD +/- 15.7). Twelve patients (11.4%) had candidemia. Crude mortality was 23% (24 patients), whereas the mortality attributable to candidemia was 25% (3/12 cases). Anemia (p = 0.001); transfusions (p = 0.003), and an ICU stay (p = 0.002) were associated with mortality. Candidemia was associated with neoplasms (p = 0.02) and the infection caused by Candida parapsilosis (p = 0.04). The only independent factor related to mortality was the anemia (p = 0.028; Odds Ratio: 6.43; 95% CI: 1.23-33.73).

CONCLUSIONS

Colonization and/or infection by Candida spp. in non-ICU hospitalized surgical patients implies a relative high mortality. Anemia is an independent factor for mortality.