Prospective study of Candida species in patients at a comprehensive cancer center

Diagnosis and Treatment Challenges of Candida guilliermondii in Immunocompromised Patients: A Case Study in a Neutropenic AML Patient

Although fungal infections causing intestinal perforation and necrosis are rare, they can be particularly dangerous in immunosuppressed patients, often leading to increased mortality rates and poor prognoses. Candida species are typically surface fungi, but in patients with compromised immune systems, they can invade the small intestine and cause angioinvasive infections. A case study involving a 30-year-old female with acute myeloid leukemia (AML) illustrates this phenomenon. The patient was presented with symptoms of abdominal pain, fever, diarrhea, recurrent episodes of intestinal necrosis, hematomas due to thrombocytopenia, and subsequent postoperative enterocutaneous fistulas. Extensive testing ruled out other possible causes of intestinal necrosis and enteritis, including Crohn's and CMV diseases. Candida guilliermondi was ultimately identified in blood cultures from the periphery, peritoneal fluid, and intestinal biopsy of respected sections, indicating that it was responsible for intestinal invasion and necrosis. The patient was then treated with amphotericin B, cefepime, and metronidazole. This case highlights the potential severity of fungal infections in immunosuppressed patients, particularly Candida species, and the importance of prompt diagnosis and appropriate treatment.

Sodium houttuyfonate derived from Houttuynia cordata Thunb improves intestinal malfunction via maintaining gut microflora stability in Candida albicans overgrowth aggravated ulcerative colitis

Candida albicans is a common opportunistic pathogen and normally resides in the human gut. Increasing number of reports link the overgrowth of C. albicans to the severity of ulcerative colitis (UC). Sodium houttuyfonate (SH), a derivative of the medicinal herb Houttuynia cordata Thunb, has been demonstrated to exhibit decent antifungal and anti-inflammatory activities. We showed previously that SH could ameliorate colitis mice infected with C. albicans. However, it is unclear whether the therapeutic effect of SH is connected to its modulation of intestinal microflora in UC. In this study, the impact of SH on the gut microbiota was explored in both cohabitation and non-cohabitation patterns. The results showed that in UC mice inflicted by C. albicans, the administration of SH could greatly improve the pathological signs, weaken the oxidative stress and inflammatory response, and enhance the intestinal mucosal integrity. By 16S rRNA gene sequencing, we found that C. albicans interference caused intestinal microbiota dysbiosis accompanied by an increase of some harmful pathogens including Klebsiella and Bacteroides. In contrast, SH could modulate the abundance and diversity of microbiota with an increase of several beneficial bacteria comprising short-chain fatty acid-producing bacteria (Lachnospiraceae_NK4A136_group, Intestinimonas) and probiotics (Lactobacillus and Alloprevotella). Furthermore, the cohabitation strategy could also prove the efficacy of SH, indicating a role of transmissible gut flora in the colitis model. These findings suggest that SH might be an effective compound for the treatment of UC complicated by C. albicans overgrowth through maintaining gut microbiota homeostasis, thereby improving intestinal function.

Evaluation of Candidiasis in Upper-Aerodigestive Squamous Cell Carcinoma Patients—A Clinico-Mycological Aspect

Candida is a commensal yeast. It can be infective when the host’s defense mechanism is weakened, as in the case of squamous cell carcinoma patients. We aimed to evaluate the prevalence and clinical mycological manifestation of candidiasis in 150 cancer cases comprised of preoperative and post-operative (with or without radiotherapy) upper aerodigestive squamous cell carcinoma. A total of 150 patients suffering from squamous cell carcinoma of the Upper Aero-Digestive Tract (UADT) were divided into preoperative (n = 48), post-operative without radiotherapy (n = 29) and post-operative with radiotherapy (n = 73). Samples were collected using cotton swabs and cultured. Candida species were identified according to color pigmentation on Candida Differential Agar (CDA) plate. The clinico-mycological association of patients was evaluated by the chi-square test, and 98 out of 150 patients showed the presence of various Candida species. The major species isolated was Candida albicans (53%), followed by Candida tropicalis (16%). There was a significant statistical difference between patients who showed mycological associations and patients who did not have any such association (p = 0.0008). The prevalence of oral candidiasis was found to be 65.33% among total cases of upper aero-digestive squamous cell carcinoma. Chronic erythematous cases of candidiasis were mainly seen in preoperative squamous cell carcinoma cases, whereas the acute erythematous type of candidiasis was mainly seen in post-operative cases who received radiotherapy. The clinicomycological assessment can help to correlate the signs and symptoms with the presence of candidiasis in upper aerodigestive squamous cell carcinoma patients. Meticulous testing and examination can help in the early detection of candidiasis. Future studies are needed to develop advance scientific preventive strategies for high-risk cases.

Antifungal activity of liriodenine on agents of systemic mycoses, with emphasis on the genus Paracoccidioides

BACKGROUND

Endemic systemic mycoses remain a health challenge, since these opportunistic diseases are increasingly infecting immunosuppressed patients. The simultaneous use of antifungal compounds and other drugs to treat infectious or non-infectious diseases has led to several interactions and undesirable effects. Thus, new antifungal compounds should be investigated. The present study aimed to evaluate the activity of liriodenine extracted from Annona macroprophyllata on agents of systemic mycoses, with emphasis on the genus Paracoccidioides.

METHODS

The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined by the microdilution method. The cellular alterations caused by liriodenine on a standard P. brasiliensis (Pb18) strain were evaluated by transmission and scanning electron microscopy.

RESULTS

Liriodenine was effective only in 3 of the 8 strains of the genus Paracoccidioides and in the Histoplasma capsulatum strain, in a very low concentration (MIC of 1.95 μg.mL-1); on yeasts of Candida spp. (MIC of 125 to 250 μg.mL-1), including C. krusei (250 μg.mL-1), which has intrinsic resistance to fluconazole; and in Cryptococcus neoformans and Cryptococcus gattii (MIC of 62.5 μg.mL-1). However, liriodenine was not effective against Aspergillus fumigatus at the studied concentrations. Liriodenine exhibited fungicidal activity against all standard strains and clinical isolates that showed to be susceptible by in vitro tests. Electron microscopy revealed cytoplasmic alterations and damage to the cell wall of P. brasiliensis (Pb18).

CONCLUSION

Our results indicate that liriodenine is a promising fungicidal compound that should undergo further investigation with some chemical modifications.

Efficient Front-Rear Coupling in Neutrophil Chemotaxis by Dynamic Myosin II Localization

Efficient chemotaxis requires rapid coordination between different parts of the cell in response to changing directional cues. Here, we investigate the mechanism of front-rear coordination in chemotactic neutrophils. We find that changes in the protrusion rate at the cell front are instantaneously coupled to changes in retraction at the cell rear, while myosin II accumulation at the rear exhibits a reproducible 9-15-s lag. In turning cells, myosin II exhibits dynamic side-to-side relocalization at the cell rear in response to turning of the leading edge and facilitates efficient turning by rapidly re-orienting the rear. These manifestations of front-rear coupling can be explained by a simple quantitative model incorporating reversible actin-myosin interactions with a rearward-flowing actin network. Finally, the system can be tuned by the degree of myosin regulatory light chain (MRLC) phosphorylation, which appears to be set in an optimal range to balance persistence of movement and turning ability.

Oral microbiological evidence among palliative patients: An integrated systematic review

Life-limiting diseases such as cancers and its related treatments often compromise normal oral microbial flora and predispose a palliative patient to diverse oral infections. Knowledge on microbial flora in the oral cavity of patients with life-limiting diseases is essential to develop treatment options for clinical practitioners. This review aimed to systematically synthesize the published evidence on the oral microbiology of palliative patients. An integrative review was undertaken with defined search strategy from five databases with manual search through key journals and reference list. Studies included were published during the year 2000–2017 focusing on microbiological evidence associated with oral conditions among palliative patients. Candida presence was reported in the oral cavity of terminally ill patients in seven of nine articles, with Candida albicans being the predominant species. The majority of the included studies used oral swabs as a technique for isolation of the organism. This review is first to systematically synthesize the published evidence on the oral microbial flora of palliative patients, taking into account the techniques for identification of the microbiota. Larger multicenter studies may help in developing standardized clinical guidelines for the oral care of these patients.

Species distribution and susceptibility profiles of Candida species isolated from vulvovaginal candidiasis, emergence of C. lusitaniae

Background and Purpose:

The aim of the current study was to investigate the epidemiology of vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC), as well as the antifungal susceptibility patterns of Candida species isolates.

Materials and Methods:

A cross-sectional study was carried out on 260 women suspected of VVC from February 2017 to January 2018. In order to identify Candida species isolated from the genital tracts, the isolates were subjected to polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) using enzymes Msp I and sequencing. Moreover, antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines (M27-A3).

Results:

Out of 250 subjects, 75 (28.8%) patients were affected by VVC, out of whom 15 (20%) cases had RVVC. Among the Candida species, C. albicans was the most common species (42/95; 44.21%), followed by C. lusitaniae (18/95; 18.95%), C. parapsilosis (13/95; 13.69%), C. glabrata (8/95; 8.42%), C. kefyr (6/95; 6.31%), C. famata (5/95; 5.26%), C. africana (2/95; 2.11%), and C. orthopsilosis (1/95; 1.05%), respectively. Multiple Candida species were observed in 28% (21/75) of the patients. Nystatin showed the narrowest range of minimum inhibitory concentration (MIC) (0.25-16 μg/ml) against all Candida strains, whereas fluconazole (0.063-64 μg/ml) demonstrated the widest MIC range. In the current study, C. lusitaniae, as the second most common causative agent of VVC, was susceptible to all antifungal agents. Furthermore, 61.1% of C. lusitaniae isolates were inhibited at a concentration of ≤ 2 μg/ml, while 38.9% (n=7) of them exhibited fluconazole MICs above the epidemiologic cutoff values (ECV). Candida species showed the highest overall resistance against fluconazole (61.3%), followed by itraconazole (45.2%) and caspofungin (23.7%). All of C. albicans strains were resistant to itraconazole with a MIC value of ≥ 1 μg/ml; in addition, 87.5% of them were resistant to fluconazole. Moreover, 100% and 87.5% of C. glabrata strains were resistant to caspofungin and fluconazole, respectively.

Conclusion:

As the findings revealed, the majority of VVC cases were caused by non-albicans Candida species which were often more resistant to antifungal agents. Candida lusitaniae generally had fluconazole MICs above the ECV. Given the propensity of C. lusitaniae to develop resistance under drug pressure, antifungals should be administered with caution. The emergence of these species justify the epidemiological surveillance surveys to watch out the distribution of yeast species.

FK506 Resistance of Saccharomyces cerevisiae Pdr5 and Candida albicans Cdr1 Involves Mutations in the Transmembrane Domains and Extracellular Loops

The 23-membered-ring macrolide tacrolimus, a commonly used immunosuppressant, also known as FK506, is a broad-spectrum inhibitor and an efflux pump substrate of pleiotropic drug resistance (PDR) ATP-binding cassette (ABC) transporters. Little, however, is known about the molecular mechanism by which FK506 inhibits PDR transporter drug efflux. Thus, to obtain further insights we searched for FK506-resistant mutants of Saccharomyces cerevisiae cells overexpressing either the endogenous multidrug efflux pump Pdr5 or its Candida albicans orthologue, Cdr1. A simple but powerful screen gave 69 FK506-resistant mutants with, between them, 72 mutations in either Pdr5 or Cdr1. Twenty mutations were in just three Pdr5/Cdr1 equivalent amino acid positions, T550/T540 and T552/S542 of extracellular loop 1 (EL1) and A723/A713 of EL3. Sixty of the 72 mutations were either in the ELs or the extracellular halves of individual transmembrane spans (TMSs), while 11 mutations were found near the center of individual TMSs, mostly in predicted TMS-TMS contact points, and only two mutations were in the cytosolic nucleotide-binding domains of Pdr5. We propose that FK506 inhibits Pdr5 and Cdr1 drug efflux by slowing transporter opening and/or substrate release, and that FK506 resistance of Pdr5/Cdr1 drug efflux is achieved by modifying critical intramolecular contact points that, when mutated, enable the cotransport of FK506 with other pump substrates. This may also explain why the 35 Cdr1 mutations that caused FK506 insensitivity of fluconazole efflux differed from the 13 Cdr1 mutations that caused FK506 insensitivity of cycloheximide efflux.

Vulvovaginal candidiasis: species distribution of Candida and their antifungal susceptibility pattern

BACKGROUND

Vulvovaginal candidiasis is a global issue of concern due to its association with economic costs, sexually transmitted infections, and ascending genital tract infection. The aim of this study was to determine species distribution and antifungal susceptibility pattern of Candida species causing vulvovaginal candidiasis.

METHODS

A cross sectional study was conducted from November 2015 to December 2016 at the Family Guidance Association of Ethiopia. Vaginal swabs collected from study subjects that were clinically diagnosed with vulvovaginal candidiasis were cultured. Yeast identification and antifungal susceptibility testing were determined by the automated VITEK 2 compact system. The association of vulvovaginal candidiasis with possible risk factors was assessed and analyzed using SPSS version 20.

RESULTS

The overall prevalence of vulvovaginal candidiasis was 41.4%. The association of vulvovaginal candidiasis was statistically significant with previous genital tract infection (p = 0.004), number of life-time male sex partners (p = .037), and number of male sex partners in 12 month (p = 0.001). Of 87 Candida isolates recovered, 58.6% were C. albicans while 41.4% were non-albicans Candida species. The highest overall drug resistance rate of Candida species was observed against fluconazole (17.2%), followed by flycytosine (5.7%). All Candida isolates were 100% susceptible to voriconazole, caspofungin, and micafungin. C. albicans, was 100% susceptible to all drugs tested except fluconazole and flycytosine with a resistance rate of 2% each drug. C. krusei, was 100 and 33.3% resistant to fluconazole and flycytosine, respectively.

CONCLUSIONS

High prevalence rate of vulvovaginal candidiasis and observation of high prevalence rate of non-albicans Candida species in the present study substantiate, the importance of conducting continuous epidemiological surveys to measure changes in species distribution from C. albicans to non-albicans Candida species in Ethiopia. Although, fluconazole still appeared to be active against all isolates of C. albicans and non-albicans Candida species high resistance rate of C. krusei against the drug may demonstrate a search for alternative antifungal drugs when treating vulvovaginal candidiasis caused by C. krusei.

Candidal Species Identification in Malignant and Potentially Malignant Oral Lesions with Antifungal Resistance Patterns

Objective:

Candidal species identification in malignant and potentially malignant oral lesions with antifungal susceptibility.

Materials and Methods:

Oral candidal carriage, strain diversity, and antifungal susceptibility of Candida were checked for the patients having oral cancer or precancer reporting to the clinics for 1½ year. Statistically significant patients were selected and a control group was taken. A total of 105 individuals were selected and divided into three different groups. Salivary samples were taken from all the individuals. Candida detection was done using Sabouraud's agar and candidal species detection on CHROMagar. In vitro antifungal sensitivity was done using antifungal disc diffusion method.

Results:

Candida was isolated from 88.6% of patients with oral cancer and 45.7% in oral precancerous group. C. albicans was the predominant species found in 100% of oral precancerous and 71% in oral cancerous patients. Other Candid a species found were C. tropicalis (9.7%) and C. krusei (19.6%). Antifungal susceptibility showed 4.3% sensitivity to fluconazole and 100% sensitivity to amphotericin B and nystatin.

Conclusion:

Oral Candida carriage was higher in oral cancerous group and majority of them were sensitive to amphotericin B and nystatin.

Epidemiological Study onCandidaSpecies in Patients with Cancer in the Intensive Care Unit

Objectives

Although cancer survival rates have increased, serious infection complications can arise in cancer patients. Candida can occur in various tissues and has significant effects on the prognosis of patients with cancer. Thus, we conducted an epidemiological study on Candida infections in patients with cancer admitted to the intensive care unit.

Methods

A retrospective study was conducted in adult patients with cancer admitted to the intensive care unit between January 1, 2013, and December 31, 2015. Candida infection status and predictive factors for mortality were examined in 634 patients.

Results

The predictive factors for mortality included the use of steroids, use of a central venous catheter or mechanical ventilator, and identification of Candida in the blood. Patients who stayed in the surgical and intensive care unit for more than 7 days had a lower risk of death than that in those with shorter days.

Conclusion

The present study shows that invasive procedures, bloodstream infections, and the use of steroids increase the risk of mortality in Candida-infected patients with cancer. To improve the quality of life and reduce mortality, further studies are needed on the factors affecting the risk of mortality associated with Candida infection.

Inhibitory effect of probiotic lactobacilli supernatants on single and mixed non-albicans Candida species biofilm

OBJECTIVES

Oral candidiasis is one of the most common human fungal infections. While most cases of the Candida species isolated from the oral cavity are Candida albicans, a large number of candidiasis is attributed to non-albicans Candida species. In this study, we aim to evaluate the in vitro inhibition of supernatants of Lactobacillus gasseri and Lactobacillus rhamnosus on the single and mixed species biofilm of non-albicans Candida species, including Candida tropicalis, Candida krusei and Candida parapsilosis.

DESIGN

Cell-free supernatants of Lactobacillus gasseri and Lactobacillus rhamnosus were prepared. Single and mixed non-albicans Candida species biofilm were formed in the 96-well microplate and on the surfaces of medical grade silicone. Biomass and cell viability were tested with crystal violet and cell counting kit-8. In order to examine the ability of the supernatant to disrupt pre-formed biofilm, supernatant was added to 24h-old biofilms. Biofilm architecture on silicone was investigated by scanning electron microscopy and confocal laser scanning microscopy was used to examine live/dead organisms within biofilm.

RESULTS

Single and mixed species biofilms and cell viability of non-albicans Candida biofilms were inhibited by probiotic lactobacilli supernatants. Matrue biofilm formation was disrupted by lactobacilli supernatants added at 24h after biofilm initiation. Examination with confocal laser scanning microscopy and scanning electron microscopy confirmed that lactobacilli supernatants inhibited the mixed biofilms and damaged the cells.

CONCLUSIONS

Our data elucidate the inhibitory activity of probiotic lactobacilli on non-albicans Candida biofilm, so as to support their utility as an adjunctive therapeutic mode against oral candida infections.

Opportunistic Microorganisms in Oral Cavity According to Treatment Status in Head and Neck Cancer Patients

Introduction

Cancer patients receiving chemotherapy and/or radiation therapy are prone to many predisposing factors like immunosuppression, imbalance in the oral flora, hypo-salivation and local tissue damage. Therefore, considered to be at higher risk for oral bacterial and fungal infection than the general population.

Aim

To study oropharyngeal flora in head and neck cancer patients under treatment and to correlate their incidence according with Chemotherapy cycles and Radiochemotherapy.

Materials and Methods

Total 110 patients were selected for study, those were further divided into two groups, group I under Chemotherapy (CT) - 55 patients and group II under Radiochemotherapy (RCT) - 55 patients and 50 healthy individuals were taken as control. Saliva sample was collected from control and study group and inoculated on Blood agar, MacConkey agar and Sabouraud's Dextrose Agar (SDA). The identification of bacterial and fungal isolates was done by standard microbiological methods and result was calculated according to cycles of Chemotherapy and Radiochemotherapy combined. Significant differences between patients were tested using the Chi-square test or Fisher's exact test. A p-value less than 0.05 was considered as statistically significant.

Result

There were 149 culture isolates from 110 patient in which Gram Negative Bacilli (GNB) found in 63.6%, Candida spp. in 50%, Staphylococcus aureus in 8% and Normal commensal of oral cavity in 13.6% patients in study group and this was higher than control group and this difference was statistically significant in relation to all isolates individually. Relatively more microorganism were isolated during RCT (56%) in compare to CT alone (44%), among GNB- Pseudomonas (27.7%,32.3%) and Klebsiella (25%,29.4%) were most frequently isolated during CT, RCT respectively. Candida spp. were more commonly isolated from patient on RCT (63.6%) than CT (36.3%) when compared to control group (20%) among which C. tropicalis was more prevalent species. Both GNB & Candida spp. were more commonly isolated in later chemotherapy cycles (CT4, CT5 CT6).

Conclusion

Colonisation of Gram negative bacilli & Candida spp. is directly related to number of chemotherapy cycles and combined cancer therapy. Hence, prophylactic medication for these two organisms should be incorporated along with cancer therapy.

High Oral Carriage of Non-albicans Candida spp. among HIV-infected individuals

BACKGROUND

Non-albicans Candida (NAC) spp. in immunocompromised patients are linked to invasive infections with narrow treatment choice. This study aimed at comparing the oral colonization of NAC spp. between HIV and non-HIV infected individuals in Mwanza, Tanzania.

METHOD

Oral rinse of 351 HIV-infected and 639 non-HIV infected individuals were collected between March and July 2015. Phenotypic identifications of Candida spp. was done using Candida Chromogenic agar and confirmed by MALDI-TOF MS.

RESULTS

NAC spp. were detected in 36/351 (10.3%) HIV-infected individuals compared to 28/639 (4.4%) of non-HIV infected individuals; P=0.0003. In HIV infected individuals, commonly isolated NAC spp. were Candida tropicalis, 10(2.8%), C. krusei (Issatschenki orientalis) 9(2.6%) and C. glabrata 8(2.3%). While for non-HIV infected individuals C. dubliniensis 8(1.3%) and C. tropicalis 5(0.9%) were commonly detected. As CD4 count/μl decreases by one unit the risk of being colonized by NAC spp. among HIV infected individuals increases by 1% (OR 1.01, 95% CI; 1.001-1.004, P=0.001).

CONCLUSION

The prevalence of NAC spp. is high among HIV-infected individuals with low CD4 count placing them at higher risk of invasive infections. Further studies to investigate the role of NAC spp. in causing invasive infections among immunocompromised patients are recommended.

Oral Candidiasis among Cancer Patients Attending a Tertiary Care Hospital in Chennai, South India: An Evaluation of Clinicomycological Association and Antifungal Susceptibility Pattern

Oropharyngeal candidiasis is one of the common manifestations seen in cancer patients on cytotoxic therapy and invasion into deeper tissues can occur if not treated promptly. Emergence of antifungal drug resistance is of serious concern owing to the associated morbidity and mortality. The present study aims at evaluation of clinicomycological association and antifungal drug susceptibility among the 180 recruited patients with cancer on chemotherapy and/or radiotherapy with signs or symptoms suggestive of oral candidiasis. Speciation and antifungal susceptibility was done by Microbroth dilution method for fluconazole, Itraconazole, and Amphotericin B as per standard microbiological techniques. Chi-square test was used for statistical analysis (p < 0.05 was considered statistically significant). Candida albicans was the predominant species isolated (94) (58%) followed by Candida tropicalis (34) (20.9%). Fluconazole and Itraconazole showed an overall resistance rate of 14% and 14.8%, respectively. All the isolates were susceptible to Amphotericin B. There was a significant association between the presence of dry mouth and isolation of Candida (p < 0.001). Such clinicomicrobiological associations can help in associating certain symptoms with the isolation of Candida. Species level identification with in vitro antifungal susceptibility pattern is essential to choose the appropriate drug and to predict the outcome of therapy.

Candida infections among neutropenic patients

BACKGROUND

Systemic candidiasis is a major complication in neutropenic cancer patients undergoing treatment. Most systemic fungal infections emerge from endogenous microflora so the aim of the present study was to identify Candida species isolated from the different regions of body in neutropenic patients in compare with the control group.

METHODS

A total of 309 neutropenic cancer patients and 584 patients without cancer (control group) entered in the study. Molecular identification of clinical isolates was performed by PCR-RFLP technique.

RESULTS

Twenty-two out of 309 patients had candidiasis (7.1%). Male to female ratio was 1/1 and age ranged from 23 to 66 years. Colorectal cancer and acute myeloid leukemia (AML) were the most common cancers. Candida albicans was the most prevalent Candida species among neutropenic patients (50%) and control group (57.9%). Mortality rate in cancer patients was 13.6% in comparison with control group (5.2%).

CONCLUSION

Since candidiasis is an important cause of morbidity and mortality in neutropenic patients, precise identification of Candida species by molecular techniques can be useful for the appropriate selection of antifungal drugs particularly in high risk patients.

Influence of cancer treatment on the Candida albicans isolated from the oral cavities of cancer patients

PURPOSE

Cancer treatment causes mucositis and the manifestation of oral candidiasis. This study investigated the virulence properties and antifungal susceptibilities of Candida albicans isolated from cancer patients undergoing therapy.

METHODS

C. albicans were isolated from 49 patients on cancer treatment and 21 healthy individuals and their virulence attributes measured. A correlation was determined between the length of treatment and the fungal counts and their virulence factors.

RESULTS

Although Candida carriage was similar in all the study groups, high quantities of C. albicans and variety of Candida were found in cancer patients. Germ tubes were produced by all the strains. Significantly high number of yeast isolated from radiotherapy and chemotherapy produced large quantities of phospholipase compared to healthy individuals (p < 0.01). The length of chemotherapy was associated with an increase in the phospholipase production (p = 0.03) by the C. albicans. Proteinase production was seen in a significant number of isolates from the radiotherapy group (p < 0.01). Type of cancer treatment had no effect. Resistance to antifungal agents was low.

CONCLUSIONS

High quantities of phospholipase were produced by C. albicans in cancer patients on therapy which also increased with the length of chemotherapy suggesting enhanced risk of oral and systemic infection. Therefore, during treatment, prophylactic topical antifungal therapy may be considered.

Oropharyngeal candidiasis in children with lymphohematopoietic malignancies in Mashhad, Iran

Background and Purpose:

Over the past years, the role of fungi as a cause of nosocomial infections in hospitalized patients has been accentuated. Candida species constitute an important group of fungi causing diseases in immunocompromised patients. Oropharyngeal candidiasis continues to be a prevalent infection in immunodeficient patients. In this study, we aimed to determine the incidence of oropharyngeal candidiasis in children with lymphohematopoietic malignancies.

Materials and Methods:

In total, 102 patients with lymphohematopoietic malignancies and 50 healthy controls were examined in terms of Candida infections via direct sampling of the oropharyngeal cavity. Fresh smears were prepared with 10% potassium hydroxide and Gram staining was carried out. Subsequently, the obtained specimens were cultured on Sabouraud dextrose agar for further analysis.

Results:

The most common Candida species were Candida albicans (31%), other non-C. albicans species (14.7%), C. glabrata (6.8%), and C. krusei (0.98%) in the case group, while in the control group, other non-C. albicans species (10%) and C. albicans (8%) were the most common species.

Conclusion:

In the present study, Candida species were the most common fungal pathogens in pediatric cancer patients; therefore, efforts should be made to prevent fungemia and fungal pneumonia. Also, non-C. albicans species must be considered as a new risk factor for pediatric cancer patients.

Ultrasensitive rapid detection of human serum antibody biomarkers by biomarker-capturing viral nanofibers

Candida albicans (C. albicans) infection causes high mortality rates within cancer patients. Due to the low sensitivity of the current diagnosis systems, a new sensitive detection method is needed for its diagnosis. Toward this end, here we exploited the capability of genetically displaying two functional peptides, one responsible for recognizing the biomarker for the infection (antisecreted aspartyl proteinase 2 IgG antibody) in the sera of cancer patients and another for binding magnetic nanoparticles (MNPs), on a single filamentous fd phage, a human-safe bacteria-specific virus. The resultant phage is first decorated with MNPs and then captures the biomarker from the sera. The phage-bound biomarker is then magnetically enriched and biochemically detected. This method greatly increases the sensitivity and specificity of the biomarker detection. The average detection time for each serum sample is only about 6 h, much shorter than the clinically used gold standard method, which takes about 1 week. The detection limit of our nanobiotechnological method is approximately 1.1 pg/mL, about 2 orders of magnitude lower than that of the traditional antigen-based method, opening up a new avenue to virus-based disease diagnosis.

Design and evaluation of peptide nucleic acid probes for specific identification of Candida albicans

Candida albicans is an important cause of systemic fungal infections, and rapid diagnostics for identifying and differentiating C. albicans from other Candida species are critical for the timely application of appropriate antimicrobial therapy, improved patient outcomes, and pharmaceutical cost savings. In this work, two 28S rRNA-directed peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) probes, P-Ca726 (targeting a novel region of the ribosome) and P-CalB2208 (targeting a previously reported region), were evaluated. Hybridization conditions were optimized by using both fluorescence microscopy (FM) and flow cytometry (FCM), and probes were screened for specificity and discriminative ability against a panel of C. albicans and various nontarget Candida spp. The performance of these PNA probes was compared quantitatively against that of DNA probes or DNA probe/helper combinations directed against the same target regions. Ratiometric analyses of FCM results indicated that both the hybridization quality and yield of the PNA probes were higher than those of the DNA probes. In FCM-based comparisons of the PNA probes, P-Ca726 was found to be highly specific, showing 2.5- to 5.5-fold-higher discriminatory power for C. albicans than P-CalB2208. The use of formamide further improved the performance of the new probe. Our results reinforce the significant practical and diagnostic advantages of PNA probes over their DNA counterparts for FISH and indicate that P-Ca726 may be used advantageously for the rapid and specific identification of C. albicans in clinical and related applications, especially when combined with FCM.

In vivo imaging of disseminated murine Candida albicans infection reveals unexpected host sites of fungal persistence during antifungal therapy

OBJECTIVES

Candida albicans is an important fungal pathogen that can cause life-threatening disseminated infections. To determine the efficacy of therapy in murine models, a determination of renal fungal burden as cfu is commonly used. However, this approach provides only a snapshot of the current situation in an individual animal and cryptic sites of infection may easily be missed. Thus, we aimed to develop real-time non-invasive imaging to monitor infection in vivo.

METHODS

Bioluminescent C. albicans reporter strains were developed based on a bioinformatical approach for codon optimization. The reporter strains were analysed in vitro and in vivo in the murine model of systemic candidiasis.

RESULTS

Reporter strains allowed the in vivo monitoring of infection and a determination of fungal burden, with a high correlation between bioluminescence and cfu count. We confirmed the kidney as the main target organ but additionally observed the translocation of C. albicans to the urinary bladder. The treatment of infected mice with caspofungin and fluconazole significantly improved the clinical outcome and clearance of C. albicans from the kidneys; however, unexpectedly, viable fungal cells persisted in the gall bladder. Fungi were secreted with bile and detected in the faeces, implicating the gall bladder as a reservoir for colonization by C. albicans after antifungal therapy. Bile extracts significantly decreased the susceptibility of C. albicans to various antifungals in vitro, thereby probably contributing to its persistence.

CONCLUSIONS

Using in vivo imaging, we identified cryptic sites of infection and persistence of C. albicans in the gall bladder during otherwise effective antifungal treatment. Bile appears to directly interfere with antifungal activity.

Treatment of invasive candidiasis in the elderly: a review

Fungi are major causes of infections among immunocompromised or hospitalized patients with serious underlying diseases and comorbidities. Candida species remain the most important cause of opportunistic infections worldwide, affecting predominantly patients over 65 years old, while they are considered to be the fourth most common cause of nosocomial bloodstream infections. The rapidly growing elderly population has specific physiological characteristics, which makes it susceptible to colonization and subsequent infection due to Candida species. Comorbidities and multidrug use should be taken into account any time the therapeutic regimen is under consideration. Different classes of antifungal drugs are available for the treatment of invasive fungal infections but echinocandins, apart from their activity against resistant strains (Candida glabrata and Candida krusei), seem to be safe, with limited adverse events and minimal drug-drug interactions in comparison to the other regimens. Therefore, these agents are strongly recommended when dealing with elderly patients suffering from an invasive form of Candida infection.

Incidence and risk factors for infection in oral cancer patients undergoing different treatments protocols

BACKGROUND

Over the past decade, advances in cancer treatments have been counterbalanced by a rising number of immunosuppressed patients with a multitude of new risk factors for infection. Hence, the aim of this study was to determine risk factors, infectious pathogens in blood and oral cavity of oral cancer patients undergoing different treatment procedures.

METHODS

The present prospective cohort analysis was conducted on the patients undergoing treatment in the radiotherapy unit of Regional Cancer Institute, Pt. B.D. Sharma University of Health Sciences, Rohtak, Haryana, during the period of January 2007 to October 2009. Total 186 patients with squamous cell carcinoma of oral cavity were analyzed in the study. Based on treatment procedures patients were divided into three groups, group I were under radiotherapy, group II under chemotherapy and group III were of radio chemotherapy together. Clinical isolates from blood and oral cavity were identified by following general microbiological, staining and biochemical methods. The absolute neutrophile counts were done by following the standard methods.

RESULTS

Prevalent bacterial pathogens isolated were Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus mirabilis, Proteus vulgaris and the fungal pathogens were Candida albicans, Aspergillus fumigatus. The predominant gram negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumonia were isolated from blood of radiotherapy and oral cavity of chemotherapy treated cases respectively. The predominance of gram positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) were observed in blood of chemotherapy, radio chemotherapy cases and oral cavity of radiotherapy, radio chemotherapy treated cases. Our study also revealed the presence of C. albicans fungi as most significant oral cavity pathogens in radiotherapy and radio chemotherapy cases.

CONCLUSION

Gram positive bacteria and Gram negative were reported from the blood of all the three groups of patients. Oral mucositis played a significant role in oral cavity infection and make patients more prone to C. albicans infection.

Doxorubicin selects for fluconazole-resistant petite mutants in Candida glabrata isolates

Candida infections are a permanent threat to immunocompromised individuals such as cancer patients, and Candida glabrata has emerged as a major problem in recent years. Resistance may develop during lengthy antifungal therapies and is often mediated by upregulation of fungal drug efflux pumps. During chemotherapy the yeast cell is also exposed to cytotoxic agents that may affect its drug susceptibility. Four C. glabrata isolates, three susceptible and one resistant to fluconazole (FLU), were incubated with 20 μg/ml of doxorubicin (DOX) for 90 min. In a second experiment, the isolates were cultured with DOX for ten days. Samples were taken on subsequent days to determine the minimal inhibitory concentration (MIC) of FLU and to analyze expression of CgCDR1, CgCDR2, CgSNQ2 and CgPDR1. Samples were also used to assess the petite phenotype. Short-term DOX exposure did not induce efflux pump gene expression, but genes were consistently overexpressed in FLU-susceptible isolates during long-term exposure. An increase in MIC values on day 6 in two of the isolates coincided with the first occurrence of petite mutants in all susceptible isolates. The respiratory deficiency of selected petite mutants was confirmed by culturing mutants on agar containing glycerol as the sole carbon source. FLU MIC values for respiratory-deficient clones were ≥64 μg/ml, and efflux pump gene expression was greatly increased. The resistant isolate did not develop mitochondrial dysfunction. In summary, the cytotoxic agent DOX selects for FLU-resistant respiratory-deficient C. glabrata mutants, which may affect antifungal therapy.

Infections in patients with hematologic neoplasms and hematopoietic stem cell transplantation: neutropenia, humoral, and splenic defects

Infections are common in patients with hematologic neoplasms and following allogeneic hematopoietic transplantation. Neutropenia and defects in adaptive B-cell-mediated immunity and/or lack of splenic function predispose patients to a host of diverse and often serious infections. It is important to recognize that patients who undergo treatment for hematologic neoplasms may have mixed immune defects, and their vulnerability to infection may continue to change, in part as a reflection of the dynamic developments in the practice of oncology. The main obstacle in providing targeted, evidence-based antimicrobial treatment is the unpredictable results of even the new generation of diagnostic assays. A definite diagnosis for most end-organ opportunistic diseases requires tissue samples that are seldom available. Because immune defects may coexist, empirical therapy is directed toward a wide spectrum of pathogens. Real-time information about innate and adaptive immune functions and the role of acute and chronic phase molecules may improve target-specific therapy.

Effect of traditional Chinese medicinal herbs on Candida spp. from patients with HIV/AIDS

As an opportunistic infection, candidiasis is common among individuals infected with HIV. About 90% of patients develop oral and/or oropharyngeal candidiasis in various stages of AIDS. Triazole antifungal agents, such as fluconazole and itraconazole, are considered to be first-choice agents for treatment and prevention because of their relatively low side effects and high effectiveness on mucosal infections. However, with prolonged exposure to azoles, drug resistance becomes a challenge for clinicians and patients alike. In traditional Chinese medicine, more than 300 herbs have been discovered to have "pesticidal" activities, and some of these have been used as antifungal agents in clinical practice for many years. Crude extracts from a number of medicinal herbs have been shown to exhibit antifungal activities in vitro. These include cortex moutan, cortex pseudolaricis, rhizoma alpiniae officinarum, rhizoma coptidis, clove and cinnamon, anemarrhena cortex phellodendri, ramulus cinnamomi, and Chinese gall. The effective anti-Candida principals were identified to be berberine, palmatine, allincin, pseudolaric acid A and B, magnolol, honokiol, and galangin. Thus, traditional Chinese medicinal herbs provide abundant choices for the treatment of refractory candidiasis commonly seen in HIV/AIDS patients. However, there remains a need for further screening of effective extracts and for study of the antifungal mechanisms involved. Importantly, ahead of clinical application, the safety of these compounds must be firmly established.

Peptide derived from anti-idiotypic single-chain antibody is a potent antifungal agent compared to its parent fungicide HM-1 killer toxin peptide

Based on anti-idiotypic network theory in light of the need for new antifungal drugs, we attempted to identify biologically active fragments from HM-1 yeast killer toxin and its anti-idiotypic antibody and to compare their potency as an antifungal agent. Thirteen overlapping peptides from HM-1 killer toxin and six peptides from its anti-idiotypic single-chain variable fragment (scFv) antibodies representing the complementarity determining regions were synthesized. The binding affinities of these peptides were investigated and measured by Dot blot and surface plasmon resonance analysis and finally their antifungal activities were investigated by inhibition of growth, colony forming unit assay. Peptide P6, containing the potential active site of HM-1 was highly capable of inhibiting the growth of Saccharomyces cerevisiae but was less effective on pathogenic fungi. However, peptide fragments derived from scFv antibody exerted remarkable inhibitory effect on the growth of pathogenic strains of Candida and Cryptococcus species in vitro. One scFv-derived decapeptide (SP6) was selected as the strongest killer peptide for its high binding affinity and antifungal abilities on both Candida and Cryptococcus species with IC(50) values from 2.33 × 10(-7) M to 36.0 × 10(-7) M. SP6 peptide activity was neutralized by laminarin, a β-1,3-glucan molecule, indicating this peptide derived from scFv anti-idiotypic antibody retains antifungal activity through interaction with cell wall β-glucan of their target fungal cells. Experimental evidence strongly suggested the possibility of development of anti-idiotypic scFv peptide-based antifungal agents which may lead to improve therapeutics for the management of varieties of fungal infections.

A comparative histopathological study of systemic candidiasis in association with experimentally induced breast cancer

Systemic candidiasis is a fungal infection which coupled with solid malignancies places patients at high risk of succumbing to the disease. Few studies have shown evidence of the relationship between systemic candidiasis and malignancy-induced immunosuppression disease especially in breast cancer. At present, animal studies that exclusively demonstrate this relationship have yet to be conducted. The exact causative mechanism of systemic candidiasis is currently under much speculation. This study therefore aimed to demonstrate this relationship by observing the histopathological changes of organs harvested from female Balb/c mice which were experimentally induced with breast cancer and inoculated with systemic candidiasis. The mice were randomly assigned to five different groups (n=12). The first group (group 1) was injected with phosphate buffer solution, the second (group 2) with systemic candidiasis, the third (group 3) with breast cancer and the final two groups (groups 4 and 5) had both candidiasis and breast cancer at two different doses of candidiasis, respectively. Inoculation of mice with systemic candidiasis was performed by an intravenous injection of Candida albicans via the tail vein following successful culture methods. Induction of mice with breast cancer occurred via injection of 4T1 cancer cells at the right axillary mammary fatpad after effective culture methods. The prepared slides with organ tissues were stained with hematoxylin and eosin, periodic acidic schiff and gomori methenamine silver stains for a histopathological analysis. Grading of primary tumour and identification of metastatic deposits, as well as scoring of inflammation and congestion in all the respective organs was conducted. Statistical tests performed to compare groups 2 and 4 showed that group 4 exhibited a highly statistically significant increase in organ inflammation and congestion (p<0.01). The median severity of candidiasis in the kidneys and liver also increased in group 4 as compared to group 2. In conclusion, based on the above evidence, systemic candidiasis significantly increased in mice with breast cancer.

Candida glabrata fungaemia in a tertiary centre in Taiwan: antifungal susceptibility and outcomes

The proportion of non-albicans candidaemia has increased during recent decades, especially Candida glabrata. We evaluated the antifungal susceptibility, clinical features and outcome of C. glabrata fungaemia treated in a tertiary centre in Taiwan. All episodes of C. glabrata fungaemia during 1999-2005 were identified from microbiology laboratory records and all C. glabrata isolates were subjected to antifungal susceptibility testing by the broth microdilution method. A total of 177 episodes of C. glabrata fungaemia were documented, accounting for 30% of the 598 episodes of candidaemia. A dramatic decline of C. glabrata causing candidaemia from 2003 (46.8%) to 2005 (15.8%) was noted, accompanied by decreased fluconazole consumption. The most common underlying diseases in these patients were cancer (49%), diabetes (34%) and renal failure (25%). The most common risk factors were central venous catheter use (88%), antimicrobial treatment (87%) and parenteral nutrition (51%). The 30-day all-cause mortality was 48.6%, but only 31% of patients were eventually discharged from the hospital. There was no significant survival difference between patients with C. glabrata and Candida albicans fungaemia. Rates of antifungal susceptibility were 63% for fluconazole, 93% for voriconazole, 96% for caspofungin, 98% for amphotericin B and 99% for flucytosine. The different levels of susceptibility to fluconazole (susceptible, susceptible-dose dependent and resistant) were not significantly associated with 30-day mortality.

Candida albicans–macrophage interactions: genomic and proteomic insights

Candida albicans infection is a significant cause of morbidity and mortality in immunocompromised patients. In vivo and in vitro models have been developed to study both the fungal and the mammalian immune responses. Phagocytic cells (i.e., macrophages) play a key role in innate immunity against C. albicans by capturing, killing and processing the pathogen for presentation to T cells. The use of microarray technology to study global fungal transcriptional changes after interaction with different host cells has revealed how C. albicans adapts to its environment. Proteomic tools complement molecular approaches and computational methods enable the formulation of relevant biological hypotheses. Therefore, the combination of genomics, proteomics and bioinformatics tools (i.e., network analyses) is a powerful strategy to better understand the biological situation of the fungus inside macrophages; part of the fungal population is killed while a significantly high percentage survives.

Bloodstream infections in haematology: risks and new challenges for prevention

Bloodstream infections are an important cause of morbidity and mortality in the haematology population, and may contribute to delayed administration of chemotherapy, increased length of hospitalisation, and increased healthcare expenditure. For gram-positive, gram-negative, anaerobic and fungal infections, specific risk factors are recognised. Unique host and environmental factors contributing to pathogenesis are acknowledged in this population. Trends in spectrum and antimicrobial susceptibility of pathogens are examined, and potential contributing factors are discussed. These include the widespread use of empiric antimicrobial therapy, increasingly intensive chemotherapeutic regimens, frequent use of central venous catheters, and local infection control practices. In addition, the risks and benefits of prophylaxis, and spectrum of endemic flora are identified as relevant factors within individual centres. Finally, challenges are presented regarding prevention, early detection, surveillance and prophylaxis. To reduce the rate and impact of bloodstream infections multifaceted and customised strategies are required within individual haematology units.

Fluconazole prophylaxis: can we eliminate invasive Candida infections in the neonatal ICU?

PURPOSE OF REVIEW

Owing to the high mortality, risk of neurodevelopmental impairment and end-organ involvement with fungal infections in the neonate, prevention of invasive Candida infections in extremely preterm infants should be a priority for each neonatal ICU.

RECENT FINDINGS

Even with prompt or empiric treatment, mortality and neurodevelopmental impairment is high (57%) in infants <1000 g. Multiple studies have been performed with fluconazole prophylaxis, including a recent multicenter randomized controlled trial. All of the studies have demonstrated efficacy and safety with no increase or emergence of fungal resistance. Analysis of these studies demonstrates that fluconazole prophylaxis decreased the incidence of invasive Candida infections in high-risk infants <1000 g by 91% (P = 0.0004) and all infants <1500 g by 85% (P < 0.0001). The mortality rate from all causes was 25% lower (P = 0.029). Furthermore, studies have demonstrated that all Candida-related mortality can be eliminated in an entire neonatal ICU by targeting fluconazole prophylaxis in infants <1000 g.

SUMMARY

Targeting fluconazole prophylaxis to infants who are either <1000 g or < or =27 weeks is highly effective, safe and inexpensive, and can eliminate these infections as a cause of neurodevelopmental impairment and mortality.

Economic analysis of inadequate fluconazole therapy in non-neutropenic patients with candidaemia: a multi-institutional study

Mortality significantly increases in patients with candidaemia who receive inappropriate fluconazole therapy. The goals of this study were to compare hospital length of stay and costs for non-neutropenic patients with candidaemia treated with fluconazole based on the empirical dose and time until initiation of therapy. A retrospective cohort study was conducted of patients with candidaemia who were prescribed fluconazole at the onset of candidaemia or later. Hospital-related costs were compared based on time to initiation of fluconazole therapy and empirical fluconazole dose. A total of 192 non-neutropenic patients (55% male; mean age+/-standard deviation, 56+/-17 years) were identified. Isolated Candida species included C. albicans (59%), C. glabrata (15%), C. parapsilosis (11%), C. tropicalis (6%), C. krusei (3%) or other Candida spp. (6%). Time to initiation of fluconazole was Day 0 (35.4%), Day 1 (14.1%), Day 2 (26.6%) or Day >or=3 (23.9%). Thirty-two patients (17%) received a dose of fluconazole >or=6 mg/kg on Day 0. Total costs were lowest for patients started on fluconazole on the culture day with adequate doses ($35,459+/-25,988) compared with all other patients ($52,158+/-53,492) (P=0.0088). After controlling for covariates, each 1-day delay in fluconazole therapy was associated with increased total hospital costs of $6392+/-3000 (P=0.0344), and an adequate fluconazole dose was associated with decreased total hospital costs of $18,744+/-7173 (P=0.0097). A delay or an inadequate dose or fluconazole in patients with candidaemia was associated with increased hospital costs. Improved methods to diagnose patients with candidaemia quickly are needed.

Nosocomial fungal infections: epidemiology, diagnosis, and treatment

Invasive fungal infections are increasingly common in the nosocomial setting. Furthermore, because risk factors for these infections continue to increase in frequency, it is likely that nosocomial fungal infections will continue to increase in frequency in the coming decades. The predominant nosocomial fungal pathogens include Candida spp., Aspergillus spp., Mucorales, Fusarium spp., and other molds, including Scedosporium spp. These infections are difficult to diagnose and cause high morbidity and mortality despite antifungal therapy. Early initiation of effective antifungal therapy and reversal of underlying host defects remain the cornerstones of treatment for nosocomial fungal infections. In recent years, new antifungal agents have become available, resulting in a change in standard of care for many of these infections. Nevertheless, the mortality of nosocomial fungal infections remains high, and new therapeutic and preventative strategies are needed.

Antifungal resistance in Candida spp. isolated in Italy between 2002 and 2005 from children and adults

The activity of amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole was tested in vitro against 618 clinical Candida spp. isolates, using the broth microdilution or the disk diffusion method (voriconazole). Amphotericin B and voriconazole were the most potent antifungal agents assayed (100% of susceptible strains). Resistance to fluconazole and itraconazole was detected in three (0.7%) and 11 (2.7%) isolates of Candida albicans and in four (3.7%) isolates of Candida glabrata. Flucytosine intermediate, resistant strains, or both, were observed in C. albicans (0.3% and 0.7%), C. glabrata (2.8% intermediate) and C. tropicalis (15.2% and 15.2%). C. krusei was the least susceptible species to azoles. No statistically significant differences in the rates of resistant isolates depending on site of infection and age of the patient were observed, with the exception of C. albicans and itraconazole (higher percentage of resistance in children). At present, acquired antifungal resistance represents an uncommon finding in most Candida spp. circulating in Northern Italy.

Optimization of a myeloid cell transfusion strategy for infected neutropenic hosts

Although granulocyte transfusion is a logical, therapeutic option for neutropenic patients with refractory infections, significant technical barriers have prevented its widespread use. A novel phagocyte transfusion strategy has been developed based on activation of a human myeloid cell line HL-60. To further define the potential for HL-60 cells to recapitulate white cell transfusions, a shortened duration of activation was evaluated, facile quality control markers were defined, and the impact of low-dose irradiation on cell function was determined. Three days of activation resulted in increased cell viability and in vitro candidacidal capacity but with slightly higher cell replication compared with 7 days of activation. Cell viability and several flow cytometric measurements were accurate, quality control markers for HL-60 activation. In combination with activation, low-dose irradiation abrogated replication while sparing the candidacidal effects of the HL-60 cells. Infusion of irradiated, activated HL-60 cells improved survival of neutropenic, candidemic mice significantly. In summary, activated, irradiated HL-60 cells are microbicidal, have virtually no replicative capacity, and are safe and effective at protecting neutropenic mice against an otherwise 100% fatal candidal infection. With continued development, this strategy to recapitulate neutrophil functions has the potential to serve as an effective alternative to granulocyte transfusions.

Candida pseudorugosa sp. nov., a novel yeast species from sputum

Two yeast strains, strains XH 1026 and XH 1164, isolated from the sputum of an intensive care unit patient with acute pneumonia, were originally identified as Candida albicans and C. tropicalis, respectively. Sequence analysis of the 26S rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) region indicated that the two strains represent a novel yeast species closely related to C. rogusa. The name Candida pseudorugosa sp. nov. is therefore proposed (type strain, AS 2.3107 [CBS 10433]). The new species is able to grow at 42 degrees C and is resistant or insusceptible to amphotericin B (MIC, 2 microg/ml), caspofungin (MIC, 64 microg/ml), itraconazole (MIC, 1 microg/ml), and nystatin (MIC, 16 microg/ml); dose-dependent susceptible to fluconazole (MIC, 16 microg/ml); and susceptible to flucytosine (MIC, 0.125 microg/ml) and voriconazole (MIC, 0.125 to 0.25 microg/ml). The code for C. pseudorugosa sp. nov. provided by the API 20C AUX system is identical to that for C. rugosa. The colonies of the new species on CHROMagar Candida appear blue-green, similar to those of C. albicans. In addition to the molecular method based on D1/D2 domain or ITS region sequencing, use of the combination of the API system and CHROMagar Candida is helpful for the correct identification of C. pseudorugosa sp. nov.

Multilocus sequence typing reveals intrafamilial transmission and microevolutions of Candida albicans isolates from the human digestive tract

Candida albicans is a human commensal that is also responsible for superficial and systemic infections. Little is known about the carriage of C. albicans in the digestive tract and the genome dynamics that occur during commensalisms of this diploid species. The aim of this study was to evaluate the prevalence, diversity, and genetic relationships among C. albicans isolates recovered during natural colonization of the digestive tract of humans, with emphasis on Crohn's disease patients who produce anti-yeast antibodies and may have altered Candida sp. carriage. Candida sp. isolates were recovered from 234 subjects within 25 families with multiple cases of Crohn's disease and 10 control families, sampled at the oral and fecal sites. Prevalences of Candida sp. and C. albicans carriage were 53.4% and 46.5%, respectively, indicating frequent commensal carriage. No differences in prevalence of carriage could be observed between Crohn's disease patients and healthy subjects. Multilocus sequence typing (MLST) of C. albicans isolates revealed frequent colonization of a subject or several members of the same family by genetically indistinguishable or genetically close isolates. These latter isolates differed by loss-of-heterozygosity events at one or several of the MLST loci. These loss-of-heterozygosity events could be due to either chromosome loss followed by duplication or large mitotic recombination events between complementary chromosomes. This study was the first to jointly assess commensal carriage of C. albicans, intrafamilial transmission, and microevolution. The high frequency of each of these events suggests that the digestive tract provides an important and natural niche for microevolutions of diploid C. albicans through the loss of heterozygosity.

Pdr1 regulates multidrug resistance in Candida glabrata: gene disruption and genome-wide expression studies

Candida glabrata emerged in the last decade as a common cause of mucosal and invasive fungal infection, in large part due to its intrinsic or acquired resistance to azole antifungals such as fluconazole. In C. glabrata clinical isolates, the predominant mechanism behind azole resistance is upregulated expression of multidrug transporter genes CDR1 and PDH1. We previously reported that azole-resistant mutants (MIC >or= 64 microg ml(-1)) of strain 66032 (MIC = 16 microg ml(-1)) similarly show coordinate CDR1-PDH1 upregulation, and in one of these (F15) a putative gain-of-function mutation was identified in the single homologue of Saccharomyces cerevisiae transcription factors Pdr1-Pdr3. Here we show that disruption of C. glabrata PDR1 conferred equivalent fluconazole hypersensitivity (MIC = 2 microg ml(-1)) to both F15 and 66032 and eliminated both constitutive and fluconazole-induced CDR1-PDH1 expression. Reintroduction of wild-type or F15 PDR1 fully reversed these effects; together these results demonstrate a role for this gene in both acquired and intrinsic azole resistance. CDR1 disruption had a partial effect, reducing fluconazole trailing in both strains while restoring wild-type susceptibility (MIC = 16 microg ml(-1)) to F15. In an azole-resistant clinical isolate, PDR1 disruption reduced azole MICs eight- to 64-fold with no effect on sensitivity to other antifungals. To extend this analysis, C. glabrata microarrays were generated and used to analyse genome-wide expression in F15 relative to its parent. Homologues of 10 S. cerevisiae genes previously shown to be Pdr1-Pdr3 targets were upregulated (YOR1, RTA1, RSB1, RPN4, YLR346c and YMR102c along with CDR1, PDH1 and PDR1 itself) or downregulated (PDR12); roles for these genes include small molecule transport and transcriptional regulation. However, expression of 99 additional genes was specifically altered in C. glabrata F15; their roles include transport (e.g. QDR2, YBT1), lipid metabolism (ATF2, ARE1), cell stress (HSP12, CTA1), DNA repair (YIM1, MEC3) and cell wall function (MKC7, MNT3). These azole resistance-associated changes could affect C. glabrata tissue-specific virulence; in support of this, we detected differences in F15 oxidant, alcohol and weak acid sensitivities. C. glabrata provides a promising model for studying the genetic basis of multidrug resistance and its impact on virulence.

Treatment of Candida glabrata infection in immunosuppressed mice by using a combination of liposomal amphotericin B with caspofungin or micafungin

While Candida albicans remains the most common Candida isolate, Candida glabrata accounts for approximately 15 to 20% of all Candida infections in the United States. In this study we used immunosuppressed mice infected with C. glabrata to investigate the efficacy of liposomal amphotericin B alone or in combination with the echinocandin caspofungin or micafungin. For monotherapy, mice were given six daily doses of liposomal amphotericin B (3 to 20 mg/kg of body weight), caspofungin (1 to 5 mg/kg), or micafungin (2.5 to 10 mg/kg). With concomitant therapy, mice received liposomal amphotericin B (7.5 mg/kg) in addition to caspofungin (2.5 mg/kg) or micafungin (2.5 mg/kg) for 6 days. For sequential therapy, liposomal amphotericin B was administered on days 1 to 3 and caspofungin or micafungin was given on days 4 to 6; conversely, caspofungin or micafungin was administered on days 1 to 3 and liposomal amphotericin B was given on days 4 to 6. Efficacy was based on the number of CFU per gram of kidney 21 days postchallenge. Monotherapy with liposomal amphotericin B (7.5 to 20 mg/kg) was significantly more effective than no drug treatment (control group) (P < 0.05) and demonstrated a dose-dependent response, with 20 mg/kg lowering the CFU/g from 6.3 to 4.2 (significantly different from the value for the control group [P < 0.001]). Monotherapy with all echinocandin doses lowered the CFU/g from 6.0 to 6.4 to 2.7 to 3.3 (significantly different from the value for the control group [P < 0.001]) with no dose-dependent response. Complete clearance of infection could be achieved only when liposomal amphotericin B was given either concomitantly with caspofungin or micafungin or if liposomal amphotericin B was given sequentially with caspofungin. In conclusion, the combination of liposomal amphotericin B with an echinocandin markedly improved the therapeutic outcome in murine C. glabrata systemic infection.

Molecular subtyping of clinical isolates of Candida albicans and identification of Candida dubliniensis Malaysia

The genotypes of 221 recent isolates of Candida albicans from various clinical specimens of 213 patients admitted to the University Malaya Medical Centre, Malaysia was determined based on the amplification of a transposable intron region in the 25 S rRNA gene. The analyses of 178 C. albicans isolated from nonsterile clinical specimens showed that they could be classified into three genotypes: genotype A (138 isolates), genotype B (38 isolates) and genotype C (2 isolates). The genotyping of 43 clinical isolates from sterile specimens showed that they belonged to genotype A (29 isolates), genotype B (10 isolates), genotype C (2 isolates) and genotype D (2 isolates). The overall distribution of C. albicans genotypes in sterile and nonsterile specimens appeared similar, with genotype A being the most predominant type. This study reported the identification of C. dubliniensis (genotype D) in 2 HIV-negative patients with systemic candidiasis, which were missed by the routine mycological procedure. The study demonstrated the genetic diversity of clinical isolates of C. albicans in Malaysia.

Genetic relationship between human and animal isolates of Candida albicans

Analyzing Candida albicans isolates from different human and animal individuals by Ca3 fingerprinting, we obtained no evidence for host-specific genotypes and for the existence of species-specific lineages, even though a certain degree of separation between human and animal isolates was found. Therefore, animals could potentially serve as reservoirs for human Candida infection.

Recombinant interferon γ1b immune enhancement in 20 patients with hematologic malignancies and systemic opportunistic infections treated with donor granulocyte transfusions

BACKGROUND

The response to antifungal therapy alone often is suboptimal in patients with cancer who have therapy-refractory neutropenia, and even donor-derived granulocyte transfusions (GTX) are not always successful. The authors evaluated the safety and efficacy of immune enhancement using recombinant interferon gamma1b (rIFN-gamma1b) in patients with cancer who received GTX for refractory, systemic, opportunistic infections.

METHODS

Twenty recipients of high-dose donor GTX ( approximately 5.5 x 10(10) neutrophils per transfusion) who had received concurrent rIFN-gamma1b between October 2001 and December 2004 were evaluated retrospectively.

RESULTS

The median age (+/- standard deviation [SD]) was 45 +/- 17 years. Ten patients (50%) were men, 17 patients (85%) had leukemia, and 3 patients (15%) had myelodysplastic syndrome. The median +/- SD Acute Physiology and Chronic Health Evaluation II score was 15 +/- 4 (range, 7-22). Most patients (n = 18 patients; 90%) had recurrent or refractory cancer. In 6 patients (30%) who received allogeneic hematopoietic stem cell transplantation, GTX plus rIFN-gamma1b was given a median +/- SD of 26 +/- 100 days (range, 12-372 days) after transplantation. Seventeen patients (85%) had neutropenia during GTX therapy. Five patients (25%) had possible invasive fungal infection, 3 patients (15%) had probable invasive fungal infection, and 11 patients (55%) had proven invasive fungal infection. One patient (5%) had refractory Pseudomonas aeruginosa sepsis. Eight patients (40%) received corticosteroids during GTX plus rIFN-gamma1b therapy. Patients received a median +/- SD of 8 +/- 7 GTX doses (range, 4-28 doses) and 9 +/- 7 rIFN-gamma1b doses (range, 1-28 doses), for a mean +/- SD cumulative dose (CD) of 400 +/- 2621 microg. Other concomitant cytokines were granulocyte-colony stimulating factor (12 +/- 3 doses; CD, 6720 +/- 4721 microg) in 15 patients (75%) and granulocyte-macrophage-colony stimulating factor (12 +/- 9 doses; CD, 4750 +/- 4410 microg) in 14 patients (70%). Four patients (20%) developed fever, and 2 patients (10%) developed skin rashes. Reversible liver dysfunction (n = 3 patients; 15%) and tachycardia (n = 1 patients; 5%) were considered rIFN-gamma1b-associated adverse reactions; whereas, in 1 patient (5%), transient dyspnea was attributed to GTX. Four weeks after therapy started, 9 patients (45%) had complete or partial resolution of infection; and, in another 3 patients (15%), the invasive fungal infection had become stable.

CONCLUSIONS

The current results indicated that no serious adverse events were associated with rIFN-gamma1b immune enhancement in patients with systemic opportunistic infections who received donor GTX therapy.

Current treatment strategies for disseminated candidiasis

The incidence of disseminated candidiasis has increased dramatically over the past several decades. Fortunately, in recent years, a variety of new antifungal agents have become available to treat these infections. On the basis of efficacy, safety, and cost considerations, fluconazole is the agent of choice for the empirical treatment of disseminated candidiasis in nonneutropenic, hemodynamically stable patients, unless a patient is suspected to be infected with an azole-resistant species (i.e., Candida glabrata or Candida krusei). For hemodynamically unstable or neutropenic patients, agents with broader species coverage, such as polyenes, echinocandins, or, possibly, voriconazole, are preferred for empirical treatment of candidemia. Modification of the initial, empirical regimen depends on the response to therapy and the subsequent identification of the species of the offending pathogen. Echinocandins or high-dose polyenes are preferred for the treatment of infections with C. glabrata or C. krusei. Central venous catheters should be removed from all patients who have disseminated candidiasis, if feasible, and antifungal therapy should be administered to all patients who have candidemia or proven candidiasis.