Combination antifungal therapy for breakthrough invasive mould disease in patients with haematological malignancies: when management reasoning eclipses evidence-based medicine

Timely diagnosis and treatment of invasive mould disease is challenging in severely immunocompromised patients, particularly for patients who develop breakthrough infections while on antifungal prophylaxis. Currently, there are no high-quality data on how to best diagnose and treat these infections. Many essential decisions affecting the management of breakthrough mould disease are made before a definitive diagnosis is established. In this scenario, sound management reasoning often favours the use of combination antifungal therapy, especially when antifungal resistance, suspicion of undetected sites of infection or pharmacokinetic/pharmacodynamic limitations at the site of infection are likely. In these scenarios, pre-emptive use of antifungal combination therapy with frequent re-evaluation with an aim of de-escalation could be justified for many high-risk patients.

Serum bactericidal titres for monitoring antimicrobial therapy: current status and potential role in the management of multidrug-resistant Gram-negative infections

BACKGROUND

Serum bactericidal titres (SBTs) were widely used in the 1970s and 1980s to monitor antimicrobial therapy but are now seldom recommended. It is the only laboratory test that integrates drug pharmacodynamics, host pharmacokinetics and synergistic or antagonistic interactions of antimicrobial combinations into a single index of antimicrobial activity. We hypothesized that SBTs could play a renewed role in monitoring antibiotic treatment of multidrug-resistant Gram-negative infections. However, the last critical appraisal of the test was published over 30 years ago.

OBJECTIVES

This narrative review provides an updated assessment of the SBT test and its methodological limitations. We performed a diagnostic meta-analysis to estimate the value of SBTs for predicting clinical failure or death during antibiotic treatment.

SOURCES

A comprehensive literature search of PubMed including all English publications was performed in December 2019 using the Medical Subject Headings (MeSH search terms "serum", "bactericidal", "inhibitory", "titre", "monitoring", "anti-infective agents" "antimicrobial therapy" and "therapeutic drug monitoring").

CONTENT

Although standardized methods for performing SBTs were approved in 1999, the test remains labour intensive, and results may not be available until 72 hr. However, the use of non-culture-based endpoints (i.e. spectrophotometric or fluorescent) may shorten test time to 24 hr. Despite considerable heterogeneity in published studies, a meta-analysis of 11 evaluable studies published from 1974 to 2007 indicated a critical SBT result (peak SBT ≤1:8 or trough ≤1:2) is associated with a diagnostic odds ratio for clinical failure during antibiotic treatment of 12.27 (95% confidence interval 5.28-28.54) and a 5.32 (95% 1.32-21.42) odds of death.

IMPLICATIONS

SBTs have prognostic value for identifying patients at high risk for antibiotic treatment failure, but the slow turnaround time of the current test limits its clinical utility. Standardization of a more rapid SBT testing method is needed.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Treatment duration for Escherichia coli bloodstream infection and outcomes: retrospective single-centre study

OBJECTIVES

To investigate the impact of treatment duration on mortality and on relapse in patients with Escherichia coli bloodstream infection (BSI).

METHODS

Retrospective single-centre study of patients diagnosed with E. coli BSI at our centre over a 4-year period.

EXCLUSION CRITERIA

age <18 years, clinical data not available, polymicrobial BSI, failure to receive in vitro active therapy, and death while receiving antibiotic therapy. Exposure variable was treatment duration dichotomized into short (≤10 days) and long (>10 days) therapy. Primary end point was all-cause mortality within 90 days after index BSI. Secondary end point was relapse, defined as repeat isolation of E. coli from blood cultures within 90 days after index BSI, in patients with documented clinical cure and completion of therapy for the initial episode.

RESULTS

Of the 856 analysed patients: 426 received short and 430 received long therapy. All-cause mortality at day 90 occurred in 47 patients; on multivariate analysis, short therapy was not associated with a higher risk of mortality, also after adjusting the model for the propensity score of receiving short therapy. Relapse occurred in 42 patients. Independent risk factors for relapse using death as competing risk were immunosuppression (subhazard ratio 4.67, p < 0.001), and end-stage liver disease (subhazard ratio 2.58, p 0.013). The propensity-weighted estimation of the average treatment effect for relapse reduction with long therapy (>10 days) was -1.6% (p 0.26) in the total population, and -7.1% (p 0.18) in immunocompromised patients.

CONCLUSIONS

We could not identify shorter treatment duration as a risk factor for mortality and for relapse in patients with E. coli BSI.

A prospective international Aspergillus terreus survey: an EFISG, ISHAM and ECMM joint study

OBJECTIVES

A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B susceptibility of Aspergillus terreus species complex infections.

METHODS

A total of 370 cases from 21 countries were evaluated.

RESULTS

The overall prevalence of A. terreus species complex among the investigated patients with mould-positive cultures was 5.2% (370/7116). Amphotericin B MICs ranged from 0.125 to 32 mg/L, (median 8 mg/L).

CONCLUSIONS

Aspergillus terreus species complex infections cause a wide spectrum of aspergillosis and the majority of cryptic species display high amphotericin B MICs.

Characterization of antibody response in neuroinvasive infection caused by Toscana virus

OBJECTIVES

Among sandfly-borne pathogens, Toscana virus (TOSV) is a prominent cause of summer meningitis in Mediterranean Europe. Here, we assessed the kinetics of anti-TOSV antibodies over time in 41 patients diagnosed with TOSV meningitis or meningoencephalitis in northeastern Italy.

METHODS

Acute and follow-up serum samples were collected up to 20 months after diagnosis of TOSV infection and tested for the presence of specific antibody using immunoenzymatic and indirect immunofluorescence assays. In addition, maturation of anti-TOSV IgG over time was evaluated as well as production of neutralizing antibodies.

RESULTS

Specific IgM and IgG response was present at diagnosis in 100% of patients; TOSV-specific IgM and IgG were detected in patients' sera up to 6 and 20 months after diagnosis, respectively. The avidity index (AI) increased over the first month after infection in 100% of patients and most cases exceeded 60% by Day 30 post infection. The AI subsequently plateaued then declined at 20 months after diagnosis. Finally, neutralization assay to TOSV was performed in 217 sera collected from 41 patients; 69.6% of tested samples resulted in reactive and moderate levels of neutralizing antibodies observed during all phases of infection despite high titres of total anti-TOSV IgG.

CONCLUSIONS

Specific antibody response develops rapidly and is long-lasting for neuroinvasive TOSV infection. Serodiagnosis of neuroinvasive TOSV requires simultaneous detection of specific IgM and IgG. Moderate levels of neutralizing antibodies were maintained over the study period, while the protective role of antibodies lacking neutralizing activity is unclear and requires further evaluation.

Antifungal prophylaxis in liver transplant recipients: one size does not fit all

BACKGROUND

Targeted antifungal prophylaxis against Candida species or against Candida species and Aspergillus species, according to individual patient risk factors (RFs), is recommended by experts. However, recent studies have reported fluconazole is as effective as broader spectrum antifungals for preventing invasive fungal infection (IFI) after liver transplantation (LT).

METHODS

We performed a retrospective cohort study of all adult patients who underwent LT at our 1420-bed tertiary teaching hospital, from June 2010 to December 2014, to assess the rate and etiology of IFI within 100 days after LT, to investigate the compliance with targeted prophylaxis, and to analyze risk factors for developing IFI.

RESULTS

In total, 303 patients underwent LT. Patients were classified as having low (no RFs), intermediate (1 RF for invasive candidiasis [IC]), and high risk (1 RF for invasive aspergillosis [IA] or ≥2 RFs for IC) for IFI in 20%, 30%, and 50% of cases, respectively. A total of 139 patients received antifungal prophylaxis: 98 with a mold-active drug and 41 with fluconazole. Overall adherence to targeted prophylaxis was 53%. Nineteen patients (6.3%) developed IFI: 7 IC and 12 IA. Multivariate Cox regression analysis, adjusted for median model for end-stage liver disease score at LT, stratification risk group, and adherence to targeted prophylaxis, showed that graft dysfunction, renal replacement therapy, and prophylaxis with fluconazole were independent risk factors for IFI. Seven of the 9 patients who received fluconazole prophylaxis and developed IFI were classified as having high risk for IFI, and 6 developed IA.

CONCLUSION

Recommended stratification is accurate for predicting patients at very high risk for IFI, who should receive prophylaxis with a mold-active drug.

Risk factors for carbapenem-resistant Klebsiella pneumoniae bloodstream infection among rectal carriers: a prospective observational multicentre study

Knowledge of carbapenem-resistant Klebsiella pneumoniae (CR-KP) colonization is important to prevent nosocomial spread but also to start prompt adequate antibiotic therapy in patients with suspicion of infection. However, few studies have examined the incidence and risk factors for CR-KP bloodstream infection (BSI) among rectal carriers. To identify risk factors for CR-KP BSI among carriers, we performed a multicentre prospective matched case-control study of all adult CR-KP rectal carriers hospitalized in five tertiary teaching hospitals in Italy over a 2-year period. Carriers who developed CR-KP BSI were compared with those who did not develop subsequent BSI. Overall, 143 CR-KP BSIs were compared with 572 controls without a documented infection during their hospitalization. Multivariate analysis revealed that admission to the Intensive Care Unit (ICU) (OR, 1.65; 95% CI, 1.05-2.59; p 0.03), abdominal invasive procedure (OR, 1.87; 95% CI, 1.16-3.04; p 0.01), chemotherapy/radiation therapy (OR, 3.07; 95% CI, 1.78-5.29; p <0.0001), and number of additional colonization sites (OR, 3.37 per site; 95% CI, 2.56-4.43; p <0.0001) were independent risk factors for CR-KP BSI development among CR-KP rectal carriers. A CR-KP BSI risk score ranging from 0 to 28 was developed based on these four independent variables. At a cut-off of ≥2 the model exhibited a sensitivity, specificity, positive predictive value and negative predictive value of 93%, 42%, 29% and 93%, respectively. Colonization at multiple sites with CR-KP was the strongest predictor of BSI development in our large cohort of CR-KP rectal carriers.

Azoles and antidepressants: a mini-review of the tolerability of co-administration

Depression is a common condition in chronically ill immunosuppressed patients on long-term antifungal therapy with azoles. As both azoles and more recent antifungals are metabolised by the P450 enzymatic system in the liver, here we review the potential of clinically meaningful interactions between antidepressants and azoles. Selective serotonin reuptake inhibitors are safer compared to tricycle antidepressants when co-administered with azoles. More pharmacovigilance is needed.

Does pre-exposure of Aspergillus fumigatus to voriconazole or posaconazole in vitro affect its virulence and the in vivo activity of subsequent posaconazole or voriconazole, respectively? A study in a fly model of aspergillosis

OBJECTIVES

Voriconazole and posaconazole are effective as both prophylaxis and treatment for invasive aspergillosis (IA) in immunocompromised patients. Hence, it is important to determine whether Aspergillus pre-exposure to voriconazole or posaconazole diminishes subsequent posaconazole or voriconazole activity, respectively.

METHODS

We used Aspergillus fumigatus (AF) 293 conidia with or without prior exposure to voriconazole or posaconazole [three serial passages on plates containing regular yeast extract-glucose (YAG) media, YAG+0.0625 mg/L voriconazole or YAG+0.025 mg/L posaconazole]. Toll-deficient Drosophila melanogaster flies were infected by injection, and 8 day survival was monitored. Following infection, flies were fed either regular food, food containing 1000 mg/L voriconazole (posaconazole-exposed conidia) or 1000 mg/L posaconazole (voriconazole-exposed conidia). Voriconazole and posaconazole concentrations in flies were confirmed by HPLC.

RESULTS

AF inoculation resulted in 71% mortality 8 days post-infection (median survival 4 days). Prior conidial exposure to voriconazole or posaconazole did not affect mortality (73%, P = 0.8 for voriconazole pre-exposed and 76%, P = 0.49 for posaconazole pre-exposed). Voriconazole treatment post-infection had a protective effect, reducing mortality to 42% (P = 0.0002), while prior conidial exposure to posaconazole did not alter the protective effect of voriconazole (34% 8 day mortality, P = 0.35). Likewise, posaconazole treatment post-infection reduced mortality to 36%, while prior conidial exposure to voriconazole did not alter the protective effect of posaconazole (39% mortality, P = 0.92). Median fly homogenate concentrations of voriconazole and posaconazole were 0.44 and 2.05 mg/L, respectively.

CONCLUSIONS

Prior exposure of AF to voriconazole or posaconazole did not affect the virulence of AF nor the subsequent activity of the alternate triazole in a Drosophila model of IA.

Multifunctional glycoprotein receptors for insulin and the insulin-like growth factors

Insulin and the insulin-like growth factors (IGF) I and II are structurally related peptides that elicit a large number of similar biological effects in target cells. Three well-characterized receptor complexes bind one or more of these peptides with high affinity. Two of these receptors, denoted as type I, are ligand-activated tyrosine kinases with similar heterotetrameric alpha 2 beta 2 subunit structures which bind insulin or IGF-I, respectively, with highest affinity. Ligand-stimulated tyrosine autophosphorylation of these receptors further activates their intrinsic tyrosine kinase activities both in vitro and in intact cells. Rapid signal transduction follows such receptor autophosphorylation and tyrosine kinase activation, leading to increased serine phosphorylation of many cellular proteins and decreased serine phosphorylation of several others. Experiments in our laboratory have identified three distinct insulin-activated serine kinase activities in cell-free extracts that appear to account for the insulin-stimulated serine phosphorylation of the insulin receptor itself, ATP citrate lyase, and acetyl CoA carboxylase, respectively. A third receptor in this group binds IGF-I and II, lacks kinase activity and is denoted as type II IGF receptor. Amino acid sequences of this receptor deduced from isolated rat cDNA clones show a high degree of homology with those of the bovine cation-independent mannose 6-phosphate (Man-6-P) receptor. We demonstrated that these receptors are indeed identical. The IGF-II/Man-6-P receptor rapidly recycles between the cell surface membrane and intracellular membrane compartments, providing for the rapid uptake of both IGF-II and mannose 6-phosphate-linked lysosomal enzymes. Insulin action markedly increases the proportion of receptors in the plasma membrane and the uptake of bound ligands. We also observe that large amounts of the extracellular domain of the IGF-II/Man-6-P receptor are released into the serum of fetal, neonatal and adult rats. The biological role of this receptor in IGF-II function is yet to be determined.

Aspergillus nidulans is frequently resistant to amphotericin B

The high failure rate of amphotericin B-based therapy in patients with Aspergillus nidulans infections may not be entirely a result of host factors as suggested previously. Innate resistance of A. nidulans to polyenes may contribute to the poor response in patients.

Cellular and molecular alterations in spinal cord injury patients with pressure ulcers: a preliminary report

The study was designed to investigate the changes, both numerically and functionally, of the molecules critical to wound healing in spinal cord injury (SCI) patients. Spinal cord injury patients who demonstrated delayed healing of their pressure ulcers were used as study subjects. Age-matched healthy individuals served as controls. Adhesion molecule expression of the peripheral blood leukocytes, including lymphocytes and granulocytes, was measured by flow cytometric analysis. Binding capacity of the lymphocytes was evaluated using human umbilical cord vein endothelial cells (HUVECs) as the binding matrix. Samples from pressure ulcers of the patients were immunostained to define fibronectin, kalinin, beta4 integrin, alpha2beta1, alpha3beta1, alpha5beta1, and CD138 expression. Compared to healthy controls, there was decreased expression of CD11a, CD11b, CD18, CD49b, CD49c, CD49d, CD54, and CD8 in patients' lymphocyte populations and CD11a, CD18, CD49c, CD49d, and CD8 in patients' granulocyte populations. The binding capacity, expressed as percentage binding of the lymphocytes to the HUVEC matrix, was greatly diminished in the patients. There was markedly diminished immunohistochemical staining of fibronectin in pressure ulcers. These findings showed that delayed healing of pressure ulcers in SCI patients can be attributed to reduced adhesion molecule expression, impaired cell-cell interaction, and lack of extracellular matrix structural and functional protein.

Pulmonary candidiasis in patients with cancer: an autopsy study

For patients who had cancer and autopsy-proven pneumonia, we evaluated whether cultures of respiratory secretions (sputum and/or bronchoalveolar lavage) performed < or =4 weeks before autopsy were a reliable basis for the diagnosis of pulmonary candidiasis. Pulmonary candidiasis was identified at autopsy in 36 patients, but common clinical predictors were insensitive for this diagnosis. For sputum culture, the sensitivity, specificity, and the positive and negative predictive values were 85%, 60%, 42%, and 93%, respectively; for bronchoalveolar lavage culture, these values were 71%, 57%, 29%, and 89%, respectively.

Comparison of Etest, chequerboard dilution and time-kill studies for the detection of synergy or antagonism between antifungal agents tested against Candida species

Currently, there is considerable debate regarding the best in vitro method for testing antifungal combinations against Candida spp. In this study, we compared the results obtained by chequerboard dilution, time-kill studies and Etest for several antifungal combinations against Candida spp. Three Candida albicans isolates (fluconazole MICs of 1.0, 32 and >256 mg/L) and three non-albicans Candida isolates (C. glabrata, C. tropicalis and C. krusei) were tested in RPMI 1640 medium. By chequerboard testing, the majority of antifungal combinations were found to be indifferent. Notably, antagonism was identified by time-kill studies and by Etest for combinations of amphotericin B-fluconazole, but it was not detected by the chequerboard method. Pre-exposure of isolates to fluconazole did not affect results of the Etest or chequerboard method, but it did increase the frequency of antagonism noted by time-kill methods. This study indicates that chequerboard dilution testing in RPMI medium may not reliably detect the attenuation of amphotericin B activity. Of the three methods, Etest was the simplest to use and yielded reproducible results for testing antifungal combinations.

PARP co-activates B-MYB through enhanced phosphorylation at cyclin/cdk2 sites

PARP is a multifunctional protein that can affect genome stability, transcription control, telomere length and cell death. Recently we have reported that PARP binds to and enhances B-MYB transactivating potential. B-MYB is a potentially oncogenic transcription factor involved in mammalian cell proliferation, survival and differentiation. B-MYB gene expression is growth regulated and B-MYB protein is phosphorylated during S phase by cyclin A or E/cdk2 kinase, resulting in augmented transactivating potential. Here we show that PARP induces phosphorylation of B-MYB protein at cdk2 phosphorylation sites, since a B-MYB protein with mutated cdk2 phosphorylation sites is refractory to PARP-induced phosphorylation and co-activation in mammalian cells. We propose that PARP functions as a B-MYB co-factor by promoting cyclin/cdk2-dependent B-MYB phosphorylation. These results highlight a novel role for PARP as a factor that integrates cyclin-dependent kinases signaling with gene transcription.

Candida lusitaniae catheter-related sepsis

OBJECTIVE

To present a case describing Candida lusitaniae candidemia in an immunocompetent patient successfully treated with fluconazole antifungal therapy. Time-kill studies of the C. lusitaniae isolate using amphotericin B, and an extensive review of the literature are also presented.

CASE SUMMARY

A 52-year-old immunocompetent Latin-American woman was admitted to the special care unit with severe sepsis. Her recent medical history included an exploratory laparotomy for gallstone pancreatitis, requiring cholecystectomy, segmental sigmoid colectomy, drainage of peritoneal abscesses, and a colostomy. In addition, the patient required a central venous catheter (CVC) placement for prolonged broad-spectrum antibiotic therapy and total parenteral nutrition therapy. Yeast was isolated from the abdominal abscess and blood cultures obtained on day 1, and from the catheter tip on day 5. The woman received initial empiric antifungal therapy with fluconazole, which was later changed to amphotericin B. After the yeast was identified as C. lusitaniae on day 8, this was changed to fluconazole for the duration of therapy. C. lusitaniae was not present in blood cultures taken two weeks after the CVC was removed, and the cultures remained negative thereafter. After a prolonged hospitalization, the patient was discharged home.

DISCUSSION

Disseminated infections with C. lusitaniae usually occur in immunocompromised patients, although isolated reports of C. lusitaniae infections in immunocompetent patients have been described. Therapeutic challenges of C. lusitaniae treatment include its primary resistance to amphotericin B and species misidentification. Isolates recovered from our patient were submitted for fungus time--kill studies that suggested unique susceptibility patterns to amphotericin B, indicating a trend toward resistance.

CONCLUSIONS

Based on variable susceptibility patterns of C. lusitaniae to amphotercin B and flucytosine, fluconazole is an appropriate choice as first-line therapy for C. lusitaniae candidemia.

A taxonomic review of the Ceratophyllus Curtis, 1832 of North America (Siphonaptera: Ceratophyllidae: Ceratophyllinae)

The 22 North American taxa assigned to the flea genus Ceratophyllus Curtis, 1832, are reviewed. All are parasites of birds and include 17 species in the nominate subgenus, 3 in Emmareus and 2 in Celeophilus. Keys to the subgenera are provided, distinguishing characters of the individual species are discussed and illustrated and the various aspects of distribution and host preferences are cited.

Evaluation of amphotericin B and flucytosine in combination against Candida albicans and Cryptococcus neoformans using time-kill methodology

In this study, time-kill methods were used to evaluate the antifungal activity of amphotericin B and flucytosine, alone and in combination, against six isolates of Candida albicans and Cryptococcus neoformans. Five regimens were tested against each isolate: (1) flucytosine, (2) low-dose amphotericin B, (3) high-dose amphotericin B, (4) low-dose amphotericin B plus flucytosine, and (5) high-dose amphotericin B plus flucytosine. Low-dose amphotericin B and flucytosine, administered alone and simultaneously, demonstrated fungistatic activity against all sample isolates except C. albicans 90028, in which fungicidal activity was detected with the combination. High-dose amphotericin B, alone and in combination, resulted in a rapid fungicidal effect in all isolates. In both the low and high-dose combinations, indifferent activity was demonstrated against all tested isolates. By virtue of the absence of an antagonistic interaction between these two agents, complementary pharmacokinetic profiles, and non-overlapping toxicities, continued clinical use of these agents in combination may be considered.

High panel reactive antibody against cross-reactive group antigens as a contraindication to renal allotransplantation

Preformed circulating cytotoxic IgG anti-HLA alloantibodies induced by previous failed grafts, blood transfusion, or pregnancy are a contraindication to allotransplantation and result in hyperacute rejection. These persistent, highly cytotoxic panel reactive antibodies (PRAs) may be specific for epitopes that are shared among HLA antigens known as cross-reactive groups (CREGs). The present investigation includes 24 subjects awaiting renal transplants with flow cytometric PRAs >30%. Eighty-seven percent of the patients developed alloantibodies specific for the mismatched antigens of previous failed grafts. The complement-dependent cytotoxicity test revealed that A1 and A2 antigens were highly immunogenic, whereas A23, B35, and B7 were less so. All patients who formed anti-A1 and anti-A2 also had developed alloantibodies specific for other antigens of the 1C and 2C CREGs, respectively. The presence of anti-class II HLA alloantibodies led to poor graft survival, i.e., a maximum of 2 years.

Rationale for combination antifungal therapy

The relentless increase of invasive fungal infections and poor outcomes associated with available antifungal agents prompted the search for better therapeutic strategies. Combining antifungal drugs was recommended as a means to enhance efficacy in a variety of invasive infections including cryptococcosis, candidiasis, and aspergillosis. With the exception of cryptococcal meningitis, data from controlled clinical trials supporting such combinations are sparse. Moreover, little consensus exists regarding which combinations are synergistic or antagonistic in vitro and in vivo. Based on available data, several principles underlie these combinations.

A review of the North American Catallagia Rothschild, 1915, with the description of a new species (Siphonaptera: Ctenophthalmidae: Neopsyllinae: Phalacropsyllini)

Catallagia duffneri Lewis and Haas is described from the Pinaleno Mountains of southeastern Arizona. The 15 known North American members of the genus are illustrated, a key to them is included and the individual species are discussed with respect to their taxonomic characters, host preferences and geographic distribution.

Histamine utilizes JAK-STAT pathway in regulating cytokine production

Histamine shifts TH1/TH2 cytokine balance from TH1 to TH2 cytokines. The phosphorylation of STAT factors and their translocation to nucleus are important steps in the regulation of TH1/TH2 cytokine balance. This study was designed to investigate the effects of histamine on Janus kinases-signal transducers and activators of transcription (JAK-STAT) pathway. The splenocytes were treated with histamine in the presence or absence of JAK-STAT inhibitor, tyrphostin, activated with IFNgamma for 30 min, and phosphorylated STAT1 was detected by immunoblotting. We found that histamine up-regulated the phosphorylation of STATI and tyrphostin prevented this phosphorylation. We then studied the effects of tyrphostin on histamine-mediated inhibition of IFNgamma production and histamine-mediated stimulation of IL-5 and IL-10 production. Tyrphostin dose-dependently reversed the effects of histamine on IFNgamma, IL-5 and IL-10 production, as evident by ELISA. These observations suggest that histamine regulated JAK-STAT signal transduction, which is involved in cytokine secretion.

Progressive disseminated aspergillosis in a bone marrow transplant recipient: response with a high-dose lipid formulation of amphotericin B

We present a case of progressive disseminated aspergillosis that involved multiple sites in a bone marrow transplant recipient with severe, chronic graft-versus-host disease. The patient failed to respond to treatment with a conventional dosage of a lipid formulation of amphotericin B (lifoAmB; 5 mg/kg/day) given alone or in combination with itraconazole, and he responded only to an aggressive strategy that included a very high dosage of lifoAmB (15 mg/kg/day) given in combination with itraconazole as well as a rapid reduction in immunosuppression. Despite the patient's abnormal baseline kidney function, the very high doses of lifoAmB were well tolerated and did not result in additional renal toxicity.

Biparental failure in the childhood experiences of borderline patients

The purpose of this study was to assess the role of biparental abuse and neglect in the development of borderline personality disorder (BPD). A semistructured research interview was used to blindly assess the childhood experiences of biparental abuse and neglect reported by 358 borderline inpatients and 109 axis II controls. Eighty-four percent of borderline patients reported having experienced some type of biparental abuse or neglect before the age of 18; 55% reported a childhood history of biparental abuse; 77% reported a childhood history of biparental neglect. These experiences were also reported by a substantial percentage of Axis II controls (biparental abuse or neglect [61%], biparental abuse [31%], and biparental neglect [55%]). However, borderline patients were significantly more likely than axis II controls to report having been verbally, emotionally, and physically but not sexually abused by caretakers of both sexes. They were also significantly more likely than controls to report having caretakers of both sexes deny the validity of their thoughts and feelings, fail to provide them with needed protection, neglect their physical care, withdraw from them emotionally, and treat them inconsistently. It was also found that female borderlines who reported a previous history of neglect by a female caretaker and abuse by a male caretaker were at significantly higher risk for having been sexually abused by a noncaretaker. Taken together, the results of this study suggest that biparental failure may be a significant factor in the etiology of BPD. They also suggest that biparental failure may significantly increase a preborderline girl's risk of being sexually abused by someone other than her parents.

Review of immune function, healing of pressure ulcers, and nutritional status in patients with spinal cord injury

The immune, neural, and endocrine systems do not act autonomously; rather, multiple communicative pathways exist among the nervous, endocrine, and immune systems that facilitate physiological immunoregulation. Patients with spinal cord injury (SCI) have decreased natural and adaptive immune responses by 2 weeks after injury. In patients with SCI, adrenocorticotropic hormone (ACTH) and urine-free cortisol levels were increased while zinc and albumin levels were decreased, respectively. In addition, the surface markers alpha 2, alpha 3, alpha 4, CD11a, CD11b, CD18, CD54, and CD8 found on lymphocytes and alpha 3, alpha 4, CD11a, CD18, and CD8 surface markers found on granulocytes were also decreased in the patient population. Finally, the adhesion molecules binding ability in the SCI group was also decreased when compared with a control group. Overall, the investigation showed that patients with SCI have a decreased immune function, especially succeeding the SCI injury, an impaired nutrition status, and a decreased number of adhesion molecules, all of which contribute to delayed wound healing.

Fate of immune complexes, glomerulonephritis, and cell-mediated vasculitis in lupus-prone MRL/Mp lpr/lpr mice

Immune complex formation was induced by the injection of (125)I-BSA into female MRL/Mp lpr/lpr mice, which develop spontaneous systemic lupus erythematosus (SLE)-like disease, and MRL/Mp +/+ mice, which do not. At designated intervals following the injection of 10 mg of (125)I-bovine serum albumin (BSA), the nonlupus mice developed sparse, small electron-dense deposits in mesangial areas and subepithelial immune deposits that underwent partial resolution. By contrast, glomeruli of the SLE-prone mouse kidneys revealed proliferation of mesangial cells and some increase in mesangial matrix material. Numerous subepithelial and mesangial electron-dense deposits were present. Some subendothelial and intramembranous deposits were also demonstrated. Capillary lumens contained massive electron-dense deposits. The resolving subepithelial deposits observed were fewer than half the number found in kidneys of the non-SLE mice. Whole body counts were also recorded daily following the injection of (125)I-BSA. Whereas, both lupus-prone and non-SLE control mice eliminated (125)I-BSA at equivalent rates through day 12 postinoculation, those with SLE-like disease showed a decreased (125)I-BSA elimination rate between days 6 and 12. Results suggest an impairment in the ability of SLE-prone mice to resolve immune complexes, whether they are nuclear-antinuclear or from an exogenous source, i.e., BSA-anti-BSA, compared to controls in this experimental model of the superimposition of exogenous immune complex formation on systemic lupus erythematosus-like disease.

A taxonomic review of the North American genus Orchopeas Jordan, 1933 (Siphonaptera: Ceratophyllidae: Ceratophyllinae)

The 20 named taxa assigned to the North American flea genus Orchopeas Jordan, 1933 are reviewed. Four of these are treated as junior synonyms and the fifth as a nomen dubium. These are: Orchopeas sexdentatus firemani Hubbard, 1955 = Orchopeas schisintus (Jordan, 1929); Orchopeas schisintus nevadensis (Jordan, 1929) = Orchopeas schisintus agilis (Rothschild, 1905); Orchopeas howardi bolivari Barrera, 1955 = Orchopeas howardi (Baker, 1895); Orchopeas howardi texensis Eads, 1950 = Orchopeas fulleri Traub, 1950 and Orchopeas labiatus (nomen dubium). Six taxa originally assigned as subspecies of Orchopeas sexdentatus are elevated to the rank of full species and distribution and host preferences of all 15 species are discussed. Illustrations of the diagnostic features of all the species are provided.

Itraconazole-amphotericin B antagonism in Aspergillus fumigatus: an E-test-based strategy

We examined an E-test-based strategy for testing the combination of itraconazole and amphotericin B, the latter given either sequentially or concomitantly, in isolates of Aspergillus fumigatus. An antagonistic interaction between the two drugs was noted, especially with the sequential administration of amphotericin B. This in vitro antagonism was reversible.

Evaluation of voriconazole pharmacodynamics using time-kill methodology

Voriconazole is an investigational azole antifungal agent with activity against a variety of fungal species, including fluconazole-susceptible and -resistant Candida species and Cryptococcus neoformans. In this study, we employed in vitro time-kill methods to characterize the relationship between concentrations of voriconazole and its fungistatic activity against Candida albicans, Candida glabrata, Candida tropicalis, and C. neoformans. Isolates were exposed to voriconazole concentrations ranging from 0.0625 to 16 times the MIC, and the viable colony counts were determined over time. The 50 and 90% effective concentrations (EC(50) and EC(90), respectively) were determined at 8, 12, and 24 h following the addition of voriconazole. At each time point, near-maximal fungistatic activity, as indicated by the EC(90), was noted at a drug concentration of approximately three times the MIC. Additionally, EC(50) and EC(90) did not change over time, thus suggesting that the rate of activity was not improved by increasing concentrations. Voriconazole exhibits non-concentration-dependent pharmacodynamic characteristics in vitro.

Comparison of oral immediate-release (IR) and extended-release (ER) metronidazole bactericidal activity against Bacteroides spp. using an in vitro model of infection

We used an anaerobic infection model capable of simulating human serum pharmacokinetic parameters (C(max), C(min), half-life, and AUC) to compare the activity of oral immediate-release (IR) and extended-release (ER) MTZ formulations. Four oral regimens of MTZ plus a control regimen were simulated in the model: [i] (IR) 500 mg q8h, [ii] ER 750 mg q12h, [iii] ER 750 mg q24h, and [iv] ER 1500 mg q24h. Two clinical Bacteroides fragilis isolates (MICs 0.5, 4.0 microg/mL) and two non-fragilis Bacteroides isolates (MICs 0.5, 3 microg/mL) were studied. All four oral MTZ regimens exhibited rapid, bactericidal activity (> or =3-log(10) decrease from the starting inoculum) within 12 h against both fragilis and non-fragilis Bacteroides isolates. Overall, no appreciable difference in the rate of bacteria killing was noted among the four MTZ formulations against either B. fragilis isolates (P = 0.907, 0.737) or non-fragilis isolates (P = 0.809, 0.768). We conclude that ER MTZ dosed at 12 or 24-h intervals possesses equivalent bactericidal activity to standard IR MTZ dosed every eight hours against susceptible Bacteroides spp.

Facilitation of immune function, healing of pressure ulcers, and nutritional status in spinal cord injury patients

Multiple communicative pathways among nervous, endocrine, and immune systems facilitate physiological immunoregulation. Spinal cord injury (SCI) patients had strikingly decreased natural and adaptive immune responses by 2 weeks post injury. While NK-cell function was decreased, plasma ACTH and urine-free cortisol levels were increased. T cell function and activation were both diminished. With rehabilitation therapy, NK and T function increased; without rehabilitation, NK levels remained depressed. When rehabilitation ceased, NK function decreased. Cervical SCI patients had less NK and T function than thoracic injury patients. SCI patients also had reduced levels of cellular adhesion molecules (CAMs) that participate in immune function and wound healing. SCI patients with pressure ulcers were compared to those without pressure ulcers. LFA-1, VLA-4, and other surface markers were decreased on the lymphocytes of all SCI patients. SCI patients with pressure ulcers had lower CAM levels than did patients without pressure ulcers. Nutritional status was determined by zinc, albumin, and prealbumin levels. SCI patients had decreased albumin levels. Those with pressure ulcers had decreased prealbumin levels and zinc levels.

In vitro pharmacodynamic characteristics of flucytosine determined by time-kill methods

Two Candida albicans isolates, three non-albicans Candida isolates (Candida glabrata, Candida krusei, and Candida tropicalis), and one Cryptococcus neoformans isolate were evaluated by time-kill methods to characterize the relationship of flucytosine concentrations to antifungal activity and the duration of the post-antifungal effect (PAE). Against Candida and Cryptococcusisolates, flucytosine at concentrations > 1 x MIC exhibited fungistatic (</=99% reduction in CFU) activity over a 24-h time-period. The rate and extent of fungistatic activity of flucytosine against all isolates was generally not increased when 5-FC concentrations exceeded 4 x MIC. A notable PAE was detected for flucytosine against both Candida and Cryptococcus species that persisted 2 to 4 h. These in vitro data suggest that flucytosine is predominately a concentration-independent fungistatic agent at clinically achieved serum concentrations. This pharmacodynamic characteristic coupled with the persistent PAE and the relatively long half-life of flucytosine in humans (> 5 h), suggests lower daily dosing may possible without loss of antifungal efficacy.

Association of HLA-DQ and -DR alleles with protection from or infection with HIV-1

Infection with human immunodeficiency virus type 1 (HIV-1) and progression to acquired immune deficiency syndrome (AIDS) are controlled by both host genetic factors and viral factors. The HLA (human leukocyte antigen) region in humans controls immune response functions and tissue rejection and influences susceptibility to neoplasia, autoimmune diseases, and infectious diseases including HIV. Twenty-eight African American and 12 Caucasian patients participated in the study. HLA-DQB1 and HLA-DRB1 genotyping was performed using PCR and sequence-specific oligonucleotide probe reverse hybridization and analyzed with the LiPA Key Typing System and LiPA software. DQB1*0603 was found to be positively associated with HIV-1 infection and with HIV-1 infection in Caucasians but not African Americans. DQB1*03032 frequencies indicate a positive association with protection from HIV-1 infection. It was further found to be protective against HIV-1 infection in Caucasians but not in African Amens. DQB1*0201 was observed more frequently in HIV(+) African Americans than HIV(-) African Americans, suggesting a positive association with HIV-1 infection in this ethnic group. HLA-DRB1*04 exhibited a positive association with HIV-1 infection in Caucasians. These data show that there are HLA class II alleles associated with susceptibility to and protection from HIV-1 infection and that these differ between ethnic groups.