Candida tropicalis fungaemia in adult patients with haematological malignancies: clinical features and risk factors

An Unusual Case of Severe Pneumonia Caused Due Candida Tropicalis With a Favorable Clinical Response to Antifungals in a Nonimmunocompromised Patient From the Community

Severe pneumonia due to Candida tropicalis infection mainly occurs in immunosuppressed patients or those currently receiving broad-spectrum antibiotics. Herein, we report a case of severe pneumonia caused due to C tropicalis in an elderly patient. A 72-year-old man with a previous history of hypertension, ischemic stroke, and facial paralysis sequelae treated with the botulinic toxin, was admitted to the hospital for dyspnea. Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection was negative. Computed tomography of the chest revealed bilateral consolidation with left predominance. A bronchoalveolar lavage sample was sent to molecular biology, but no microorganisms were detected using a FilmArray respiratory panel. However, mamanocandidas test for candida was 166 pg/mL (positive), and fungal structures were identified by the MALDI-TOF Biotyper mass spectrometry and attributed to C tropicalis. Antifungal therapy was started using caspofungin 75 mg as the initial dose followed by 50 mg daily. After 10 days of treatment, ventilatory weaning was achieved. By day 14, the patient was decannulated from the tracheostomy. Oral antifungal treatment with voriconazole was continued, and he was discharged from intensive care in good clinical condition. Severe pneumonia due to C tropicalis might occur in specific cases, especially in those patients with risk factors, and must thus be considered when approaching such cases.

Antifungal Properties of Nerolidol-Containing Liposomes in Association with Fluconazole

(1) Background: Infections by Candida species represent a serious threat to the health of immunocompromised individuals. Evidence has indicated that nerolidol has significant antifungal properties. Nonetheless, its use is restricted due to a low water solubility and high photosensitivity. The incorporation into liposomes may represent an efficient alternative to improve the physicochemical and biopharmaceutical properties of this compound. The present study aimed to characterize the antifungal properties of liposomal nerolidol, alone or in combination with fluconazole. Of note, this is the first study reporting the antifungal activity of liposomal nerolidol and its potentiating effect in association with fluconazole. (2) Methods: The Inhibitory Concentration 50%-IC₅₀ and minimum fungicide concentrations (MFC) of the substances against Candida albicans (CA), Candida tropicalis (CT), and Candida krusei (CK) were established by subculture in a solid medium. To evaluate the antifungal-enhancing effect, the MFC of fluconazole was determined in the presence or absence of subinhibitory concentrations of nerolidol (free or liposomal). The analysis of fungal dimorphism was performed through optical microscopy and the characterization of liposomes was carried out considering the vesicular size, polydispersion index, and zeta medium potential, in addition to a scanning electron microscopy analysis. (3) Results: The physicochemical characterization revealed that liposomes were obtained as homogenous populations of spherical vesicles. The data obtained in the present study indicate that nerolidol acts as an antifungal agent against Candida albicans and Candida tropicalis, in addition to potentiating (only in the liposomal form) the effect of fluconazole. However, the compound had little inhibitory effect on fungal dimorphism. (4) Conclusions: The incorporation of nerolidol into liposomes improved its antifungal-modulating properties.

Investigation of a healthcare-associated Candida tropicalis candidiasis cluster in a haematology unit and a systematic review of nosocomial outbreaks

BACKGROUND

Non-albicans Candida spp. are an emerging cause of hospital-acquired bloodstream infections, associated with high mortality due to the challenges in diagnosis and delayed treatment.

OBJECTIVES

We aimed to investigate a cluster of healthcare-associated invasive candidiasis caused by C tropicalis and review the literature of healthcare-associated outbreaks or clusters caused by C tropicalis.

METHODS

An investigation was performed to determine clinical presentation, treatment outcomes and the factors contributing to C tropicalis candidemia occurrence. We searched the Medline database via PubMed and Ovid using the keywords of "Candida tropicalis" combined with "outbreak" or "clustering" or "clusters," and we limited the search to studies conducted from January 1989 to January 2019.

RESULTS

We report two related cases of C tropicalis candidemia among patients with AML following a period of neutropenia, who had erythematous skin rash as a first manifesting sign of candidiasis. C tropicalis was isolated from blood and skin cultures of both patients, which were identical by pulsed-field gel electrophoresis typing. Our systematic review of outbreaks caused by C tropicalis suggests that (a) most reported outbreaks have occurred in neonatal and adult ICUs; (b) patients who receive total parenteral therapy, antibiotics and those who have indwelling catheters and recent surgery are at high risk of infection; and (c) environmental and healthcare personnel surveillance suggest that cross-contamination is a major risk factor.

CONCLUSION

Control of nosocomial outbreaks caused by C tropicalis should include better infection control measures, education of healthcare professionals especially working in adult and neonatal intensive care and haematology units.

Pre-clinical Imaging of Invasive Candidiasis Using ImmunoPET/MR

The human commensal yeast Candida is the fourth most common cause of hospital-acquired bloodstream infections, with Candida albicans accounting for the majority of the >400,000 life-threatening infections annually. Diagnosis of invasive candidiasis (IC), a disease encompassing candidemia (blood-borne yeast infection) and deep-seated organ infections, is a major challenge since clinical manifestations of the disease are indistinguishable from viral, bacterial and other fungal diseases, and diagnostic tests for biomarkers in the bloodstream such as PCR, ELISA, and pan-fungal β-D-glucan lack either standardization, sensitivity, or specificity. Blood culture remains the gold standard for diagnosis, but test sensitivity is poor and turn-around time slow. Furthermore, cultures can only be obtained when the yeast resides in the bloodstream, with samples recovered from hematogenous infections often yielding negative results. Consequently, there is a pressing need for a diagnostic test that allows the identification of metastatic foci in deep-seated Candida infections, without the need for invasive biopsy. Here, we report the development of a highly specific mouse IgG3 monoclonal antibody (MC3) that binds to a putative β-1,2-mannan epitope present in high molecular weight mannoproteins and phospholipomannans on the surface of yeast and hyphal morphotypes of C. albicans, and its use as a [⁶⁴Cu]NODAGA-labeled tracer for whole-body pre-clinical imaging of deep-seated C. albicans infections using antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI). When used in a mouse intravenous (i.v.) challenge model that faithfully mimics disseminated C. albicans infections in humans, the [⁶⁴Cu]NODAGA-MC3 tracer accurately detects infections of the kidney, the principal site of blood-borne candidiasis in this model. Using a strain of the emerging human pathogen Candida auris that reacts with MC3 in vitro, but which is non-infective in i.v. challenged mice, we demonstrate the accuracy of the tracer in diagnosing invasive infections in vivo. This pre-clinical study demonstrates the principle of using antibody-guided molecular imaging for detection of deep organ infections in IC, without the need for invasive tissue biopsy.

The epidemiology and outcomes of invasive Candida infections among organ transplant recipients in the United States: results of the Transplant-Associated Infection Surveillance Network (TRANSNET)

BACKGROUND

Invasive candidiasis (IC) is a common cause of mortality in solid organ transplant recipients (OTRs), but knowledge of epidemiology in this population is limited.

METHOD

The present analysis describes data from 15 US centers that prospectively identified IC from nearly 17 000 OTRs. Analyses were undertaken to determine predictors of infection and mortality.

RESULTS

A total of 639 cases of IC were identified. The most common species was Candida albicans (46.3%), followed by Candida glabrata (24.4%) and Candida parapsilosis (8.1%). In 68 cases >1 species was identified. The most common infection site was bloodstream (44%), followed by intra-abdominal (14%). The most frequently affected allograft groups were liver (41.1%) and kidney (35.3%). All-cause mortality at 90 days was 26.5% for all species and was highest for Candida tropicalis (44%) and C. parapsilosis (35.2%). Non-white race and female gender were more commonly associated with non-albicans species. A high rate of breakthrough IC was seen in patients receiving antifungal prophylaxis (39%). Factors associated with mortality include organ dysfunction, lung transplant, and treatment with a polyene antifungal. The only modifiable factor identified was choice of antifungal drug class based upon infecting Candida species.

CONCLUSION

These data highlight the common and distinct features of IC in OTRs.

Ethnicity and Other Possible Risk Factors for Candidemia at 3 Tertiary Care University Hospitals in Hawaii

A total of 108 cases of candidemia detected in 3 tertiary care university hospitals in Hawaii between January 2001 and December 2002 were retrospectively reviewed. Candida albicans, Candida glabrata, and Candida tropicalis accounted for 28% of the cases. Mortality among Filipino patients was significantly higher than that among other ethnic groups (71% vs 48%; P<.05).

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and Bayesian phylogenetic analysis to characterize Candida clinical isolates

Clinical Candida isolates from two different hospitals in Rome were identified and clustered by MALDI-TOF MS system and their origin and evolution estimated by Bayesian phylogenetic analysis. The different species of Candida were correctly identified and clustered separately, confirming the ability of these techniques to discriminate between different Candida species. Focusing MALDI-TOF analysis on a single Candida species, Candida albicans and Candida parapsilosis strains clustered differently for hospital setting as well as for period of isolation than Candida glabrata and Candida tropicalis isolates. The evolutionary rates of C. albicans and C. parapsilosis (1.93×10(-2) and 1.17×10(-2)substitutions/site/year, respectively) were in agreement with a higher rate of mutation of these species, even in a narrow period, than what was observed in C. glabrata and C. tropicalis strains (6.99×10(-4) and 7.52×10(-3)substitutions/site/year, respectively). C. albicans resulted as the species with the highest between and within clades genetic distance values in agreement with the temporal-related clustering found by MALDI-TOF and the high evolutionary rate 1.93×10(-2)substitutions/site/year.

Candida tropicalis as a Predominant Isolate from Clinical Specimens and its Antifungal Susceptibility Pattern in a Tertiary Care Hospital in Southern India

BACKGROUND

The incidence of infections caused by Candida species has increased considerably over the past three decades mainly due to the rise of the AIDS epidemic, an increasingly aged population, higher numbers of immunocompromised patients and the more widespread use of indwelling medical devices. Candida tropicalis is emerging pathogenic yeast among non-albicans species. Recently drug-resistant C.tropicalis was also reported in hospitals.

AIM AND OBJECTIVE

The present study aimed to isolate and speciate C. tropicalis from various clinical samples and to determine its antifungal susceptibility profile.

MATERIALS AND METHODS

Clinical samples such as urine, blood, exudates and vaginal swab which were submitted to the Microbiology laboratory during the year 2013 were screened for the growth of Candidia species, which then identified as C.tropicalis by the routine microbiological procedures such as germ tube formation, assimilation and fermentation of sugars and colony color on HICHROM Candida agar. Antifungal susceptibility was performed by disc diffusion method with the drugs Amphotericin-B, Itraconazole, Ketaconazole and Fluconazole on C. tropicalis isolates.

RESULTS

A total number of 112 Candida isolates were isolated during the year 2012 from various clinical specimens. Among them 61 (54.3%) were identified as C.tropicalis. All the C. tropicalis isolates were sensitive to Amphotericin-B (100%) but 23 isolates (37.7%) were resistant to Fluconazole.

CONCLUSION

We conclude that identification of Candida species is important to know the prevalent species in the clinical setup and routine antifungal susceptibility should be performed to avoid inappropriate treatment.

Incidence and species distribution of candidaemia in Asia: a laboratory-based surveillance study

The epidemiology of candidaemia varies between hospitals and geographic regions. Although there are many studies from Asia, a large-scale cross-sectional study across Asia has not been performed. We conducted a 12-month, laboratory-based surveillance of candidaemia at 25 hospitals from China, Hong Kong, India, Singapore, Taiwan and Thailand. The incidence and species distribution of candidaemia were determined. There were 1601 episodes of candidaemia among 1.2 million discharges. The overall incidence was 1.22 episodes per 1000 discharges and varied among the hospitals (range 0.16-4.53 per 1000 discharges) and countries (range 0.25-2.93 per 1000 discharges). The number of Candida blood isolates and the total number of fungal isolates were highly correlated among the six countries (R² = 0.87) and 25 hospitals (R² = 0.77). There was a moderate correlation between incidence of candidaemia and the intensive care unit (ICU)/total bed ratio (R² = 0.47), although ICUs contributed to only 23% of candidaemia cases. Of 1910 blood isolates evaluated, Candida albicans was most frequently isolated (41.3%), followed by Candida tropicalis (25.4%), Candida glabrata (13.9%) and Candida parapsilosis (12.1%). The proportion of C. tropicalis among blood isolates was higher in haemato-oncology wards than others wards (33.7% versus 24.5%, p 0.0058) and was more likely to be isolated from tropical countries than other Asian countries (46.2% versus 18.9%, p 0.04). In conclusion, the ICU settings contribute, at least in part, to the incidence variation among hospitals. The species distribution is different from Western countries. Both geographic and healthcare factors contribute to the variation of species distribution.

Calcineurin controls hyphal growth, virulence, and drug tolerance of Candida tropicalis

Candida tropicalis, a species closely related to Candida albicans, is an emerging fungal pathogen associated with high mortality rates of 40 to 70%. Like C. albicans and Candida dubliniensis, C. tropicalis is able to form germ tubes, pseudohyphae, and hyphae, but the genes involved in hyphal growth machinery and virulence remain unclear in C. tropicalis. Recently, echinocandin- and azole-resistant C. tropicalis isolates have frequently been isolated from various patients around the world, making treatment difficult. However, studies of the C. tropicalis genes involved in drug tolerance are limited. Here, we investigated the roles of calcineurin and its potential target, Crz1, for core stress responses and pathogenesis in C. tropicalis. We demonstrate that calcineurin and Crz1 are required for hyphal growth, micafungin tolerance, and virulence in a murine systemic infection model, while calcineurin but not Crz1 is essential for tolerance of azoles, caspofungin, anidulafungin, and cell wall-perturbing agents, suggesting that calcineurin has both Crz1-dependent and -independent functions in C. tropicalis. In addition, we found that calcineurin and Crz1 have opposite roles in controlling calcium tolerance. Calcineurin serves as a negative regulator, while Crz1 plays a positive role for calcium tolerance in C. tropicalis.

Epidemiology of candidaemia and invasive candidiasis. A changing face

Invasive candidiasis is a leading cause of mortality. Candidaemia is the most common clinical presentation of invasive candidiasis but more that 30% of these infections do not yield positive blood cultures. Candida albicans remains the predominant aetiology, accounting for 50% of all cases. However, there has been an epidemiological shift in the last decades. Some species of Candida different to C. albicans have emerged as an important cause of severe candidaemia as they can exhibit resistance to fluconazole and other antifungal agents. Moreover, there is a different distribution of non C. albicans Candida species in relationship to patients' and hospital characteristics. Thus, Candida parapsilosis has been associated to candidaemia in neonates and young adults. This species usually has an exogenously origin and contaminates medical devices, causing central venous catheter-associated candidaemias. Candida glabrata, Candida tropicalis and Candida krusei are isolated in blood cultures from older patients (>65 years) with important risk factors, such as major abdominal surgery, solid tumours and haematologic malignancies, transplants, and/or prolonged treatment with corticoids. Moreover, important geographical differences in the distribution of the Candida species different to C. albicans causing invasive candidiasis have been reported: C. parapsilosis predominates in Australia, Latin America and Mediterranean countries of Africa, Asia and Europe. In contrast, C. glabrata has an important aetiological role in USA and Central and Northern Europe. Finally, an important and worrying issue is that mortality due to invasive candidiasis remains unacceptably high. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

Advantages of using matrix-assisted laser desorption ionization-time of flight mass spectrometry as a rapid diagnostic tool for identification of yeasts and mycobacteria in the clinical microbiological laboratory

Yeast and mycobacteria can cause infections in immunocompromised patients and normal hosts. The rapid identification of these organisms can significantly improve patient care. There has been an increasing number of studies on using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid yeast and mycobacterial identifications. However, studies on direct comparisons between the Bruker Biotyper and bioMérieux Vitek MS systems for the identification of yeast and mycobacteria have been limited. This study compared the performance of the two systems in their identification of 98 yeast and 102 mycobacteria isolates. Among the 98 yeast isolates, both systems generated species-level identifications in >70% of the specimens, of which Candida albicans was the most commonly cultured species. At a genus-level identification, the Biotyper system identified more isolates than the Vitek MS system for Candida (75/78 [96.2%]versus 68/78 [87.2%], respectively; P = 0.0426) and non-Candida yeasts (18/20 [90.0%]versus 7/20 [35.0%], respectively; P = 0.0008). For mycobacterial identification, the Biotyper system generated reliable identifications for 89 (87.3%) and 64 (62.8%) clinical isolates at the genus and species levels, respectively, from solid culture media, whereas the Vitek MS system did not generate any reliable identification. The MS method differentiated 12/21 clinical species, despite the fact that no differentiation between Mycobacterium abscessus and Mycobacterium chelonae was found by using 16S rRNA gene sequencing. In summary, the MALDI-TOF MS method provides short turnaround times and a standardized working protocol for the identification of yeast and mycobacteria. Our study demonstrates that MALDI-TOF MS is suitable as a first-line test for the identification of yeast and mycobacteria in clinical laboratories.

Candida in saliva of Brazilian hemophilic patients

Hemophilia is a common hereditary hemorrhagic disorder, however little is known about the oral microflora of hemophilic patients. The aim of this study was to quantify the Candida and identify its species in non-stimulated saliva of hemophilic patients, and consider its relationship with clinical factors influencing Candida carriage. This study comprised evaluation of 86 hemophilic patients of the Hematology Center/UNICAMP and 43 healthy subjects as controls. All patients were submitted to anamnesis, intraoral examination and unstimulated saliva collection. Candida counts and species identification were performed in salivary samples. Candida was present in 64% of the hemophilic patients and in 44% of the healthy controls. C. albicans represented 65% and 68% of the isolated species, in hemophiliacs and control group respectively, and C. tropicalis was the second most common species in both groups. These results indicate that hemophilic patients carry Candida more frequently and in higher counts than healthy controls, independently of oral clinical parameter considered, as viral infections, complete dentures, transfusions of hemoderivatives, and salivary flow.

The increased role of non-albicans species in candidaemia: results from a 3-year surveillance study

Various studies have documented a shift in species distribution in Candida bloodstream infections (BSI), but there are little data from Southeast Asia. This study was performed to determine the species epidemiology and antifungal susceptibilities of Candida species BSI in Singapore. Candida spp. from BSI were collected from a tertiary and secondary referral hospital, and an obstetrics/paediatric hospital over a 3-year period. The most common isolates were Candida albicans (36%), Candida tropicalis (27%), Candida glabrata (16%) and Candida parapsilosis (16%). Candida parapsilosis and C. albicans were predominant in the paediatric hospital, and C. albicans and C. tropicalis predominant in the other two institutions. Candida tropicalis temporarily replaced C. albicans as the predominant strain from BSI in 2006. Overall, 87.3% of Candida isolates were susceptible to fluconazole, and 10.4% classified as susceptible-dose-dependent. Fluconazole resistance was detected in C. tropicalis (3.6%), C. parapsilosis (2.1%) and C. glabrata (4.0%). Candida albicans is the predominant species isolated from BSI in Singapore. However, non-albicans species accounted for nearly two-thirds of all cases of candidaemia and the relative increase in C. tropicalis infections deserves further investigation. Resistance to fluconazole was uncommon.

Candida tropicalis in human disease

Candida tropicalis is one of the more common Candida causing human disease in tropical countries; the frequency of invasive disease varies by geography causing 3--66% of candidaemia. C. tropicalis is taxonomically close to C. albicans and shares many pathogenic traits. C. tropicalis is particularly virulent in neutropenic hosts commonly with hematogenous seeding to peripheral organs. For candidaemia and invasive candidiasis amphotericin B or an echinocandin are recommended as first-line treatment, with extended-spectrum triazoles acceptable alternatives. Primary fluconazole resistance is uncommon but may be induced on exposure. Physicians in regions where C. tropicalis is common need to be mindful of this lesser-described pathogen.

Candida tropicalis fungaemia: incidence, risk factors and mortality in a general hospital

The risk factors and clinical features of patients with Candida tropicalis fungaemia have not been fully defined. We performed a case-control study comparing 59 cases of C. tropicalis fungaemia with 177 episodes of fungaemia caused by other species of Candida in our hospital over a 24-year period (January 1985 to December 2008). Patients with C. tropicalis fungaemia were more likely to be older (median age, 67 vs. 56 years; p 0.01), to have cancer (45.5% vs. 31.6%, p 0.04), and to have the abdomen as the portal of entry (32.2% vs. 11.9%, p 0.001), and had a higher in-hospital mortality rate (61% vs. 44%, p 0.03). Multivariate analysis showed that the independent risk factors for C. tropicalis fungaemia were cancer (OR 4.5; 95% CI 1.05-3.83; p 0.03) and the abdomen as the portal of entry (OR 13.6; 95% CI 1.9-8.2; p <0.001). When survivors were compared with non-survivors, the risk factors associated with a poor outcome were neutropenia (19.4% vs. 0; p 0.03), corticosteroid treatment (36% vs. 13%; p 0.07), and septic shock (50% vs. 17.4%; p 0.01). The independent risk factors for mortality in the multivariate analysis were corticosteroid treatment (OR 8.2; 95% CI 0.9-27.7; p 0.04) and septic shock (OR 14.6; 95% CI 2.4-90.2; p 0.004), whereas urinary tract infection (OR 0.07; 95% CI 0.01-0.8; p 0.03) and catheter removal (OR 0.06; 95% CI 0.01-0.4; p 0.002) were protective factors. C. tropicalis is the fourth most common cause of fungaemia in our hospital. It is associated with underlying malignancy, the abdomen as the portal of entry, and poor outcome.

Fungal colonisation in burn wounds: An Indian scenerio

Burn patients are susceptible hosts for fungal colonisation.

AIM

To study incidence and profile of fungal colonisation of burn wounds.

MATERIALS AND METHODS

This prospective study was conducted in 201 consecutive adult patients (39 male and 162 female) with burn wounds, admitted from October 2005 to September 2006. Wounds with clinical suspicion of fungal colonisation were biopsied and examined by wet smear, Potassium hydroxide (KOH) mount, nigrosin stain, 1% Acid fast bacilli (AFB) stain, Gomori methenamine silver (GMS) stain, histopathological examination and fungal culture. All wounds with suspicion of fungal colonisation were treated with topical application of miconazole ointment mixed with povidone-iodine/silver sulphadiazine topically and itraconazole (oral) systemically.

RESULTS

Fungal infection of burn wound was suspected in 77 patients (38.31%) with 20-70% total body surface area (TBSA) burns. Ninety-two biopsy samples were collected from 77 patients. On investigations, fungal colonisation was confirmed in 35 patients. Culture was positive in 23 patients with Candida in 12 and Aspergillus in 4. GMS stain and KOH stain showed sensitivity and specificity of 70.8% and 86.5%, respectively for detecting fungi in burn wound. Nigrosin stain was negative in all patients. Duration of hospitalisation was more in patients having fungal colonisation without any significant effect on the mortality

DISCUSSION

In 38.31% of patients fungal colonisation was clinically suspected and it was confirmed in 17.41% of 201 patients. GMS stain and KOH stain were observed to have acceptable sensitivity and specificity. With increasing prevalence of Aspergillus, flucanazole cannot be relied upon in controlling fungal colonisation and drugs like itraconazole may have to be used as empirical therapy.

CONCLUSION

Fungal colonisation of burn wound is not uncommon and should be suspected. Fungi detected most commonly were Candida and Aspergillus. KOH and GMS stain were identified as reliable, simple and inexpensive methods for confirming fungal colonisation.

Resistência a antifúngicos de Candida tropicalis isoladas no Estado do Ceará

Neste estudo, foi avaliada a resistência a drogas antifúngicas em 51 cepas de Candida tropicalis isoladas de amostras clínicas no Estado do Ceará, Brasil. Resistência antifúngica foi um evento raro no nosso estudo e foi restrita a 3 (5,9%) das cepas de Candida tropicalis, que exibiram resistência a fluconazol e itraconazol.

An unusual case of Candida tropicalis and Candida krusei arthritis in a patient with acute myelogenous leukemia before chemotherapy

A 79-year-old male with acute myelogenous leukemia developed acute right knee arthritis during admission, after the use of broad-spectrum antibiotics before chemotherapy. The initial synovial fluid sample appeared to be mildly inflammatory with a low white cell count. The fungal septic arthritis was not diagnosed until Candida tropicalis, a rare species of Candida, was isolated in the synovial fluid. Although fluconazole is effective in treating the microorganism, the untreated leukemia rendered the infection incurable and led to the growth of fluconazole-resistant Candida krusei. We reported the unusual case of fungal arthritis and reviewed the literature.

Bacterial and fungal colonization of burn wounds

A prospective study of fungal and bacterial flora of burn wounds was carried out from February 2004 to February 2005 at the Burns Unit of Hospital Regional da Asa Norte, Brasília, Brazil. During the period of the study, 203 patients were treated at the Burns Unit. Wound swab cultures were assessed at weekly intervals for four weeks. Three hundred and fifty four sampling procedures (surface swabs) were performed from the burn wounds. The study revealed that bacterial colonization reached 86.6% within the first week. Although the gram-negative organisms, as a group, were more predominant, Staphylococcus aureus (28.4%) was the most prevalent organism in the first week. It was however surpassed by Pseudomonas aeruginosa form third week onwards. For S. aureus and P. aeruginosa vancomycin and polymyxin were found to be the most effective drugs. Most of the isolates showed high level resistance to antimicrobial agents. Fungi were found to colonize the burn wound late during the second week postburn, with a peak incidence during the third and fourth weeks. Species identification of fungi revealed that Candida tropicalis was the most predominant, followed by Candida parapsilosis. It is crucial for every burn institution to determine the specific pattern of burn wound microbial colonization, the time-related changes in the dominant flora, and the antimicrobial sensitivity profiles. This would enable early treatment of imminent septic episodes with proper empirical systemic antibiotics, without waiting for culture results, thus improving the overall infection-related morbidity and mortality.

Invasive candidiasis in cancer patients: observations from a randomized clinical trial

BACKGROUND

Invasive candidiasis is a common and serious complication of cancer and its therapy.

METHODS

We retrospectively identified patients with malignancies enrolled in a double-blind randomized trial of caspofungin (50 mg/day after a 70 mg loading dose) vs. conventional amphotericin B (0.6-1.0 mg/kg/day) as treatment of documented invasive candidiasis. A favorable response required complete resolution of signs and symptoms plus eradication of the Candida pathogen(s). The primary efficacy analysis used a modified intention-to-treat (MITT) approach that included all patients with a confirmed diagnosis of invasive candidiasis who received > or =1 dose of study medication.

RESULTS

74/224 (33%) patients in the MITT population had active malignancies. 25/30 (83%) hematological malignancies were acute or chronic leukaemias. 22/44 (50%) solid tumors were related to the gastrointestinal tract. Patients with hematological malignancies tended to be younger (median [range] age: 49 [19-74] vs. 59 [19-81] years) and have higher baseline acute physiology and chronic health evaluation (APACHE) II scores (mean [range]: 17 [0-28] vs. 15 [5-35]) than patients with solid tumors. Neutropenia [< or =500/microl] was present on entry in 23 (77%) patients with hematological malignancies and in one (3%) patient with a solid tumor. Candidemia was demonstrated in 56 (88%) cancer patients. C. albicans was the single most frequent isolate in cancer patients, although the majority of cases were caused by non-albicans species. Cancer patients in the caspofungin arm had more hematological malignancies (55 vs. 29%), higher baseline APACHE II scores (>20 in 36 vs. 15%), more frequent neutropenia (42 vs. 24%), and less C. albicans infections (27 vs. 49%) than the amphotericin B-treated cancer patients. Favorable response rates were 11/18 (61%) and 6/12 (50%) for patients with hematological malignancies treated with caspofungin or amphotericin B, respectively; the corresponding outcomes in patients with solid tumors were 12/15 (80%) and 17/29 (59%) for the 2 treatment arms. 7/14 (50%) caspofungin- and 4/10 (40%) amphotericin B-treated patients who were neutropenic on entry responded favorably. All-cause mortality rates during the study for caspofungin recipients were 11/18 (61%) with hematological malignancies and 6/15 (40%) with solid tumors, and for amphotericin recipients were 4/12 (33%) with hematological malignancies and 6/29 (21%) with solid tumors.

CONCLUSIONS

Underlying cancers, most commonly leukaemias and gastrointestinal tumors, were present in one-third of patients enrolled in this study of invasive candidiasis. Overall, 70% of caspofungin-treated and 56% of amphotericin B-treated cancer patients responded favorably. Response rates were lower for neutropenic leukaemic patients than for non-neutropenic patients with solid tumors in both treatment groups.

Neonatal candidiasis: analysis of epidemiology, drug susceptibility, and molecular typing of causative isolates

A prospective observational study of invasive candidiasis was conducted in the neonatal intensive care unit of Aristotle University in Hippokration Hospital between 1994 and 2000. During this period, 59 neonates developed invasive candidiasis (58 cases of candidemia and 1 case of peritonitis), resulting in an overall incidence of 1.28% that showed a decreasing trend over the study period. Eleven (18.6%) cases developed within the first week of life and the others within a mean (+/-SEM) of 13.4+/-1.7 days after birth. The three most frequent causative species were Candida albicans (65.5%), Candida parapsilosis (15.5%), and Candida tropicalis (7%). C. albicans was the predominant species between 1994 and 1998, whereas, non-albicans Candida spp., particularly C. parapsilosis, were the most frequent species during the period 1999-2000 (P<0.001). While the overall mortality due to candidemia was 29% (17 of 59 cases), mortality associated with C. albicans and C. parapsilosis was 39.5% and 11.1%, respectively (P=0.032), and that observed in the 1999-2000 period was 0% (P=0.011). Virtually all isolates were susceptible to amphotericin B, flucytosine, fluconazole, and itraconazole, and no increases in minimal inhibitory concentrations were observed during these years. With the exception of a limited cluster of cases due to genotypically identical isolates, no clonal relation of C. albicans isolates was found. Moreover, no clonal persistence of C. albicans and no decrease in antifungal drug susceptibility occurred over the 6-year study period. Non-albicans Candida spp., mostly C. parapsilosis, have emerged as important pathogens in neonatal intensive care units, with infected patients having better outcomes as compared to patients infected with C. albicans.

Epidemiology and molecular typing of Candida isolates from burn patients

This study, spread over a span of 2 years describes Candida infections in burn patients of an Indian hospital. A total of 220 burn patients were monitored and Candida could be isolated from 138 patients. A total of 228 different Candida species were obtained from various body locations of these patients. Species identification revealed that Candida albicans was the most predominant (45%) followed by Candida tropicalis (33%), Candida glabrata (13.5%), C. parapsilosis (4%), C. krusei (2.75%) and C. kefyr (1.75%). DNA fingerprinting of all C. albicans isolates was done by using CARE-2 probe. Fingerprinting analyses of all the C. albicans strains revealed that strains collected from different patients were different. It is noteworthy that patients with disseminated candidiasis had a similar, but unique strain isolated from all body locations, suggesting a possibility that commensal isolates might be turning pathogenic. Taken together, this is probably the first ever detailed survey of Candida infections in burn patients in India and is expected to lead to better clinical management of this group of patients.

Global distribution and outcomes for Candida species causing invasive candidiasis: results from an international randomized double-blind study of caspofungin versus amphotericin B for the treatment of invasive candidiasis

In a randomized study, caspofungin was compared with amphotericin B for the treatment of invasive candidiasis in a total of 239 adults from 56 sites in 20 countries. This study provided a unique opportunity to assess the frequency and outcome of invasive candidiasis caused by different Candida species worldwide, and the results are presented here. Efficacy was primarily assessed at the end of intravenous therapy using a modified intent-to-treat (MITT) analysis. This analysis was performed on 224 of the 239 patients enrolled in the study. Attempts were made to collect baseline Candida isolates from all patients for species identification at a central laboratory. Yeasts were identified to the species level using two commercial systems and microscopic examination. Viable baseline isolates were recovered from 210 of the 224 (94%) patients included in the MITT analysis. Candida albicans was the most frequently isolated species in all regions and was responsible for 45% of cases overall. Nevertheless, the majority of cases of infection were caused by non- albicans Candida species. In the USA and Canada, Candida glabrata was the second most commonly isolated pathogen (18%). In contrast, Candida parapsilosis and Candida tropicalis accounted for 55% of cases in Latin America. Outcomes were comparable for patients treated with caspofungin (74% overall; 64% and 80% for infections due to Candida albicans and non- albicans species) and amphotericin B (62% overall; 58% and 68% for infections due to Candida albicans and non- albicans species), and were generally similar across continents. The distribution of Candida species isolated from patients enrolled in a clinical trial may not be representative of pathogens causing invasive candidiasis in the general population. Nevertheless, our findings may affect the regional choice of empirical antifungal therapy for seriously ill patients with suspected or documented invasive candidiasis since different Candida species have varying susceptibility to conventional antifungal drugs.

Candida tropicalis fungemia in a tertiary care hospital

Candida tropicalis is a frequent cause of fungemia in hospitals in Latin America. Candida albicans (33%) was the most frequently isolated species, followed by Candida parapsilosis (27%), and Candida tropicalis (24%) in tertiary care hospital in Brazil. We identified and retrospectively reviewed 27 cases of C. tropicalis fungemia that occurred at Hospital de Clinicas de Porto Alegre from 1996 to 1999. The mean age of the patients was 32 years (range 6 months to 88 years). Eight patients (29.6%) had hematological malignancy, and four (14.8%) had solid tumors. All the patients were taking broad-spectrum antibiotics, including vancomycin for at least 7 days. Antibiotics were given through a central venous catheter for the majority of the patients (77.7%). Relevant risk factors for candidemia in our patients included neutropenia (59.2%), and use of corticosteroids (37.0%) or cytotoxic drugs (40.7%). The onset of fever was the most frequent clinical manifestation (92.5%) of fungemia. Most of the patients (81.4%) were treated with amphotericin B or fluconazole. Overall mortality was 48.1%, and 7 (53.4%) of 13 deaths occurred within 10 days of the detection of candidemia. Results of the in vitro susceptibility testing of nine isolates of C. tropicalis from seven patients did not show resistance to fluconazole and amphotericin B.C. tropicalis presents as an important cause of fungemia in oncological and nononcological patients with central venous catheters taking broad-spectrum antibiotics. Although there was no evidence of resistance of C. tropicalis to amphotericin B and fluconazole, patients treated with antifungal agents presented with a high mortality rate in the hospital setting.

Candida tropicalis in a neonatal intensive care unit: epidemiologic and molecular analysis of an outbreak of infection with an uncommon neonatal pathogen

From June to July 1998, two episodes of Candida tropicalis fungemia occurred in the Aristotle University neonatal intensive care unit (ICU). To investigate this uncommon event, a prospective study of fungal colonization and infection was conducted. From December 1998 to December 1999, surveillance cultures of the oral cavities and perinea of the 593 of the 781 neonates admitted to the neonatal ICU who were expected to stay for >7 days were performed. Potential environmental reservoirs and possible risk factors for acquisition of C. tropicalis were searched for. Molecular epidemiologic studies by two methods of restriction fragment length polymorphism analysis and two methods of random amplified polymorphic DNA analysis were performed. Seventy-two neonates were colonized by yeasts (12.1%), of which 30 were colonized by Candida albicans, 17 were colonized by C. tropicalis, and 5 were colonized by Candida parapsilosis. From December 1998 to December 1999, 10 cases of fungemia occurred; 6 were due to C. parapsilosis, 2 were due to C. tropicalis, 1 was due to Candida glabrata, and 1 was due to Trichosporon asahii (12.8/1,000 admissions). Fungemia occurred more frequently in colonized than in noncolonized neonates (P < 0.0001). Genetic analysis of 11 colonization isolates and the two late blood isolates of C. tropicalis demonstrated two genotypes. One blood isolate and nine colonization isolates belonged to a single type. The fungemia/colonization ratio of C. parapsilosis (3/5) was greater than that of C. tropicalis (2/17, P = 0.05), other non-C. albicans Candida spp. (1/11, P = 0.02), or C. albicans (0/27, P = 0.05). Extensive environmental cultures revealed no common source of C. tropicalis or C. parapsilosis. There was neither prophylactic use of azoles nor other risk factors found for acquisition of C. tropicalis except for total parenteral nutrition. A substantial risk of colonization by non-C. albicans Candida spp. in the neonatal ICU may lead to a preponderance of C. tropicalis as a significant cause of neonatal fungemia.