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1.
Pediatr Infect Dis J ; 42(12): e490-e492, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37851979

ABSTRACT

In 2022, a surge in cases of pediatric human parechovirus (HPeV) central nervous system infections in young infants was seen at our institution. Despite the dramatic increase in the number of cases seen that year, the clinical features of the illness were similar to prior years. The recent pediatric HPeV surge highlights the need to evaluate treatment options and standardize follow-up to better understand the long-term prognosis of infants with HPeV infection.


Subject(s)
Central Nervous System Infections , Parechovirus , Picornaviridae Infections , Infant , Humans , Child , Picornaviridae Infections/diagnosis , Picornaviridae Infections/epidemiology , Prognosis , Central Nervous System Infections/diagnosis , Central Nervous System Infections/epidemiology
2.
Clin Infect Dis ; 77(3): 380-387, 2023 08 14.
Article in English | MEDLINE | ID: mdl-37021650

ABSTRACT

Pressing challenges in the treatment of invasive fungal infections (IFIs) include emerging and rare pathogens, resistant/refractory infections, and antifungal armamentarium limited by toxicity, drug-drug interactions, and lack of oral formulations. Development of new antifungal drugs is hampered by the limitations of the available diagnostics, clinical trial endpoints, prolonged trial duration, difficulties in patient recruitment, including subpopulations (eg, pediatrics), and heterogeneity of the IFIs. On 4 August 2020, the US Food and Drug Administration convened a workshop that included IFI experts from academia, industry, and other government agencies to discuss the IFI landscape, unmet need, and potential strategies to facilitate the development of antifungal drugs for treatment and prophylaxis. This article summarizes the key topics presented and discussed during the workshop, such as incentives and research support for drug developers, nonclinical development, clinical trial design challenges, lessons learned from industry, and potential collaborations to facilitate antifungal drug development.


Subject(s)
Invasive Fungal Infections , Mycoses , United States , Humans , Child , Antifungal Agents/therapeutic use , Mycoses/drug therapy , United States Food and Drug Administration , Invasive Fungal Infections/drug therapy , Drug Interactions
3.
Clin Microbiol Rev ; 35(4): e0008619, 2022 12 21.
Article in English | MEDLINE | ID: mdl-36448782

ABSTRACT

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.


Subject(s)
Arthritis , Mycoses , Osteomyelitis , Mycoses/diagnosis , Mycoses/drug therapy , Mycoses/epidemiology , Fungi , Aspergillus , Arthritis/drug therapy , Osteomyelitis/drug therapy , Antifungal Agents/therapeutic use
4.
Pediatrics ; 148(3)2021 09.
Article in English | MEDLINE | ID: mdl-34452978

ABSTRACT

BACKGROUND: At our institution, empirical vancomycin is overused in children with suspected bacterial community-acquired infections (CAIs) admitted to the PICU because of high community rates of methicillin-resistant Staphylococcus aureus (MRSA). Our goal was to reduce unnecessary vancomycin use for CAIs in the PICU. METHODS: Empirical PICU vancomycin indications for suspected CAIs were developed by using epidemiological risk factors for MRSA. We aimed to reduce empirical PICU vancomycin use in CAIs by 30%. After retrospectively testing, the indications were implemented and monthly PICU empirical vancomycin use during baseline (May 2017-April 2018) and postintervention (May 2018-July 2019) periods. Education was provided to PICU providers, vancomycin indications were posted, and the antibiotic order set was revised. Statistical process control methods tracked improvement over time. Proven S aureus infections for which vancomycin was not empirically prescribed and linezolid or clindamycin use were balancing measures. RESULTS: We identified 1620 PICU patients with suspected bacterial CAIs. Empirical vancomycin decreased from a baseline of 73% to 45%, a 38% relative reduction. No patient not prescribed empirical vancomycin later required the addition of vancomycin or other MRSA-targeted antibiotics. There was no change in nephrotoxicity or in the balancing measures. CONCLUSIONS: Development of clear and concise recommendations, combined with clinician education and decision support via an order set, was an effective and safe strategy to reduce PICU vancomycin use. Retrospective validation of the recommendations with local data were key to obtaining PICU clinician buy in.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Inappropriate Prescribing/prevention & control , Quality Improvement/organization & administration , Vancomycin/therapeutic use , Antimicrobial Stewardship , Bacterial Infections/drug therapy , Community-Acquired Infections/drug therapy , Decision Support Systems, Clinical , Drug Prescriptions/statistics & numerical data , Empirical Research , Humans , Intensive Care Units, Pediatric , Ohio
5.
Med Mycol ; 59(2): 189-196, 2021 Feb 04.
Article in English | MEDLINE | ID: mdl-33313821

ABSTRACT

Treatment options for Exserohilum rostratum meningoencephalitis and other causes of phaeohyphomycosis of the central nervous system (CNS) are limited, while mortality and morbidity remain high. We therefore evaluated isavuconazole, a new antifungal triazole in comparison to liposomal amphotericin B (LAMB), in vitro and in the rabbit model of Exserohilum rostratum meningoencephalitis. We hypothesized that isavuconazole alone or in combination with LAMB or micafungin may be alternative options for treatment of CNS phaeohyphomycosis. We therefore investigated the in vitro antifungal activity of isavuconazole alone or in combination with amphotericin B deoxycholate (DAMB) or micafungin and efficacy of treatment with isavuconazole and LAMB in a rabbit model of experimental E. rostratum meningoencephalitis. Combination checkerboard plates were used to determine the minimum inhibitory concentrations, minimal lethal concentrations, fractional inhibitory concentration indices, and Bliss surface analysis of isavuconazole and amphotericin B deoxycholate (DAMB), either alone or in combination. As there were no in vitro synergistic or antagonistic interactions for either combination of antifungal agents against the E. rostratum isolates, in vivo studies were conducted with isavuconazole and LAMB as monotherapies. Rabbits were divided in following groups: treated with isavuconazole at 60 mg/kg/d (ISAV60), LAMB at 5.0 (LAMB5), 7.5 (LAMB7.5), and 10 mg/kg/d (LAMB10), and untreated controls (UC). In ISAV60-, LAMB5-, LAMB7.5-, and LAMB10-treated rabbits, significant reductions of fungal burden of E. rostratum in cerebral, cerebellar, and spinal cord tissues (P < 0.01) were demonstrated in comparison to those of UC. These antifungal effects correlated with significant reduction of CSF (1→3)-ß-D-glucan levels vs UC (P < 0.05). These data establish new translational insights into treatment of CNS phaeohyphomycosis.


Subject(s)
Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Ascomycota/drug effects , Central Nervous System Diseases/drug therapy , Nitriles/therapeutic use , Phaeohyphomycosis/drug therapy , Pyridines/therapeutic use , Triazoles/therapeutic use , Amphotericin B/pharmacology , Animals , Antifungal Agents/pharmacology , Ascomycota/pathogenicity , Central Nervous System Diseases/microbiology , Disease Management , Disease Models, Animal , Drug Therapy, Combination , Female , Humans , Microbial Sensitivity Tests , Nitriles/pharmacology , Pyridines/pharmacology , Rabbits , Triazoles/pharmacology
6.
Article in English | MEDLINE | ID: mdl-32179521

ABSTRACT

Ibrexafungerp (formerly SCY-078) is a semisynthetic triterpenoid and potent (1→3)-ß-d-glucan synthase inhibitor. We investigated the in vitro activity, pharmacokinetics, and in vivo efficacy of ibrexafungerp (SCY) alone and in combination with antimold triazole isavuconazole (ISA) against invasive pulmonary aspergillosis (IPA). The combination of ibrexafungerp and isavuconazole in in vitro studies resulted in additive and synergistic interactions against Aspergillus spp. Plasma concentration-time curves of ibrexafungerp were compatible with linear dose proportional profile. In vivo efficacy was studied in a well-established persistently neutropenic New Zealand White (NZW) rabbit model of experimental IPA. Treatment groups included untreated control (UC) rabbits and rabbits receiving ibrexafungerp at 2.5 (SCY2.5) and 7.5 (SCY7.5) mg/kg of body weight/day, isavuconazole at 40 (ISA40) mg/kg/day, or combinations of SCY2.5+ISA40 and SCY7.5+ISA40. The combination of SCY+ISA produced an in vitro synergistic interaction. There were significant in vivo reductions of residual fungal burden, lung weights, and pulmonary infarct scores in SCY2.5+ISA40, SCY7.5+ISA40, and ISA40 treatment groups versus those of the SCY2.5-treated, SCY7.5-treated, and UC (P < 0.01) groups. Rabbits treated with SCY2.5+ISA40 and SCY7.5+ISA40 had prolonged survival in comparison to that of the SCY2.5-, SCY7.5-, ISA40-treated, or UC (P < 0.05) groups. Serum galactomannan index (GMI) and (1→3)-ß-d-glucan levels significantly declined in animals treated with the combination of SCY7.5+ISA40 in comparison to those of animals treated with SCY7.5 or ISA40 (P < 0.05). Ibrexafungerp and isavuconazole combination demonstrated prolonged survival, decreased pulmonary injury, reduced residual fungal burden, and lower GMI and (1→3)-ß-d-glucan levels in comparison to those of single therapy for treatment of IPA. These findings provide an experimental foundation for clinical evaluation of the combination of ibrexafungerp and an antimold triazole for treatment of IPA.


Subject(s)
Invasive Pulmonary Aspergillosis , Triterpenes , Animals , Antifungal Agents/therapeutic use , Glucans , Glycosides , Invasive Pulmonary Aspergillosis/drug therapy , Nitriles , Pyridines , Rabbits , Triazoles
7.
J Fungi (Basel) ; 5(1)2019 Jan 24.
Article in English | MEDLINE | ID: mdl-30678324

ABSTRACT

This paper reviews recent advances in three selected areas of pediatric invasive candidiasis: epidemiology, diagnosis, and treatment. Although the epidemiological trends of pediatric invasive candidiasis illustrate a declining incidence, this infection still carries a heavy burden of mortality and morbidity that warrants a high index of clinical suspicion, the need for rapid diagnostic systems, and the early initiation of antifungal therapy. The development of non-culture-based technologies, such as the T2Candida system and (1→3)-ß-d-glucan detection assay, offers the potential for early laboratory detection of candidemia and CNS candidiasis, respectively. Among the complications of disseminated candidiasis in infants and children, hematogenous disseminated Candida meningoencephalitis (HCME) is an important cause of neurological morbidity. Detection of (1→3)-ß-d-glucan in cerebrospinal fluid serves as an early diagnostic indicator and an important biomarker of therapeutic response. The recently reported pharmacokinetic data of liposomal amphotericin B in children demonstrate dose⁻exposure relationships similar to those in adults. The recently completed randomized clinical trial of micafungin versus deoxycholate amphotericin B in the treatment of neonatal candidemia provides further safety data for an echinocandin in this clinical setting.

8.
J Fungi (Basel) ; 4(2)2018 Jun 18.
Article in English | MEDLINE | ID: mdl-29912161

ABSTRACT

Species of Scedosporium and Fusarium are considered emerging opportunistic pathogens, causing invasive fungal diseases in humans that are known as scedosporiosis and fusariosis, respectively. These mold infections typically affect patients with immune impairment; however, cases have been reported in otherwise healthy individuals. Clinical manifestations vary considerably, ranging from isolated superficial infection to deep-seated invasive infection—affecting multiple organs—which is often lethal. While there have been a number of advances in the detection of these infections, including the use of polymerase chain reaction (PCR) and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS), diagnosis is often delayed, leading to substantial morbidity and mortality. Although the optimal therapy is controversial, there have also been notable advances in the treatment of these diseases, which often depend on a combination of antifungal therapy, reversal of immunosuppression, and in some cases, surgical resection. In this paper, we review these advances and examine how the management of scedosporiosis and fusariosis may change in the near future.

9.
J Pediatric Infect Dis Soc ; 6(suppl_1): S22-S31, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28927203

ABSTRACT

Invasive fungal disease (IFD) is a life-threatening condition, especially in immunocompromised children. The role of diagnostic imaging in children at risk for an IFD is multifactorial, including initially detecting it, evaluating for dissemination of infection beyond the primary site of disease, monitoring the response to antifungal therapy, and assessing for potential relapse. The objective of this review was to synthesize the published literature relevant to the use of various imaging modalities for the diagnosis and management of IFD in children.


Subject(s)
Candidiasis, Invasive/diagnostic imaging , Invasive Pulmonary Aspergillosis/diagnostic imaging , Aspergillosis, Allergic Bronchopulmonary/diagnostic imaging , Blastomycosis/diagnostic imaging , Bone Diseases, Infectious/diagnostic imaging , Bone Diseases, Infectious/microbiology , Child , Coccidioidomycosis/diagnostic imaging , Eye Infections, Fungal/diagnostic imaging , Histoplasmosis/diagnostic imaging , Humans , Immunocompromised Host , Liver Diseases/diagnostic imaging , Liver Diseases/microbiology , Lung Diseases, Fungal/diagnostic imaging , Meningoencephalitis/diagnostic imaging , Meningoencephalitis/microbiology , Mucormycosis/diagnostic imaging , Opportunistic Infections/diagnostic imaging , Opportunistic Infections/microbiology , Pneumonia/diagnostic imaging , Pneumonia/microbiology , Pneumonia, Pneumocystis/diagnostic imaging , Sinusitis/diagnostic imaging , Sinusitis/microbiology , Splenic Diseases/diagnostic imaging , Splenic Diseases/microbiology
10.
Med Mycol ; 55(8): 859-868, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-28204571

ABSTRACT

Combination therapy may be an alternative therapeutic approach for difficult-to-treat Candida infections with the aim of increasing efficacy of antifungal therapy. Whether isavuconazole, an extended-spectrum triazole, possesses synergistic activity in combination therapy with echinocandins or polyenes for the treatment of invasive candidiasis has not been studied. We used Bliss independence drug interaction analysis and time-kill assays to examine the in vitro interactions of isavuconazole with amphotericin B or micafungin, an echinocandin, against strains of Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, and Candida krusei. The Bliss independence-based drug interactions modeling showed that the combination of isavuconazole and micafungin resulted in synergistic interactions against C. albicans, C. parapsilosis, and C. krusei. The degree of synergy ranged from 1.8% to 16.7% (mean %ΔΕ value) with the highest synergy occurring against C. albicans (⊙SYN% = 8.8%-110%). Time-kill assays showed that the isavuconazole-micafungin combination demonstrated concentration-depended synergy against C. albicans and C. parapsilosis. The combined interaction by Bliss analysis between isavuconazole and amphotericin B was indifferent for C. albicans, C. parapsilosis, and C. tropicalis while for C. glabrata was antagonistic (-2% to -6%) and C. krusei synergistic (3.4% to 7%). The combination of isavuconazole-amphotericin B by time-kill assay was antagonistic against C. krusei and C. glabrata. Collectively, our findings demonstrate that combinations of isavuconazole and micafungin are synergistic against Candida spp., while those of isavuconazole and amphotericin B are indifferent in vitro.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Candida/drug effects , Echinocandins/pharmacology , Lipopeptides/pharmacology , Nitriles/pharmacology , Pyridines/pharmacology , Triazoles/pharmacology , Candidiasis, Invasive/drug therapy , Drug Synergism , In Vitro Techniques , Micafungin , Microbial Sensitivity Tests , Time Factors
11.
J Antimicrob Chemother ; 72(3): 712-716, 2017 03 01.
Article in English | MEDLINE | ID: mdl-28039272

ABSTRACT

Background: Echinocandins are an important class of antifungal agents in the treatment of invasive candidiasis. However, little is known about the metabolomic effects of echinocandins on Candida . We therefore performed LC-high-resolution MS (LC-HRMS)-based metabolomics profiling of the response of Candida albicans cells to increasing concentrations of micafungin to determine the metabolic response of Candida to micafungin subinhibitory injury. Methods: Isolates of C. albicans were cultured on nitrocellulose filters to mid-logarithmic phase of growth and micafungin (0-0.25 mg/L) was added. At mid-logarithmic phase, replicates were metabolically quenched. Intracellular metabolites were analysed by LC-HRMS. Changes in pool sizes of individual metabolites were analysed by Student's t -test adjusted for multiple hypothesis testing by Benjamini-Hochberg correction. Metabolites were ascribed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways database. Results: Among 3446 detected metabolites, 204 were identified by comparison against pure standard or comparison against a library of mass-retention-time pairs. Fifty had significantly altered abundances in response to increasing micafungin concentrations. Pool sizes of amino acids, nucleic acids and polyamine metabolism were significantly increased at subinhibitory concentrations, while exposure to inhibitory concentrations resulted in a precipitous decrease consistent with fungicidal activity. Conclusions: Micafungin induces a re-routing of metabolic pathways inhibiting protein synthesis and cell replication. These results shed light on new mechanisms of action of echinocandins.


Subject(s)
Amino Acids/metabolism , Antifungal Agents/pharmacology , Candida albicans/genetics , Candida albicans/metabolism , Echinocandins/pharmacology , Lipopeptides/pharmacology , Nucleic Acids/metabolism , Candida albicans/drug effects , Candida albicans/growth & development , Candidiasis/microbiology , Candidiasis, Invasive/microbiology , Carbon , Chromatography, Liquid , Mass Spectrometry , Metabolic Networks and Pathways/drug effects , Metabolomics , Micafungin , Microbial Sensitivity Tests
12.
Pediatr Nephrol ; 31(12): 2271-2276, 2016 12.
Article in English | MEDLINE | ID: mdl-27525699

ABSTRACT

BACKGROUND: Antimicrobial prophylaxis is recommended for the prevention of urinary tract infections (UTI) in high-risk children. However, there is growing concern about the use of ß-lactams as prophylaxis and subsequent development of antibiotic resistance. METHODS: In this prospective, randomized, crossover controlled trial we compared cotrimoxazole (SXT) and second-generation cephalosporins (2GC) as UTI prophylaxis in children ranging in age from 1 to 60 months. Eligible patients were 1:1 randomized to receive either SXT or 2GC for the initial 6-month period (1 course), then switched to the other antimicrobial agent class for the subsequent course, with switching continuing after each course until the end of the study. Urethral orifice cultures (UOCs) were obtained at the time of switching antimicrobial prophylaxis. RESULTS: Among 97 children (mean age 13.6 months) on prophylaxis, breakthrough UTIs occurred during 13.3 % (10/75) of SXT courses and 10.3 % (8/78) of 2GC courses (p = 0.62). 2GC failed earlier than SXT (mean ± standard error: 0.81 ± 0.1 vs. 2.37 ± 0.36 months, respectively; p = 0.028). Pseudomonas aeruginosa and Enterococcus spp. were more frequently isolated after 2GC courses than after SXT courses [22.6 vs. 4.8 % (p = 0.02) and 20.7 vs. 4.8 % (p = 0.035), respectively]. Prophylaxis with 2GC significantly increased resistance to both 2GC and SXT, while SXT prophylaxis did not affect susceptibility to 2GC. CONCLUSIONS: While SXT and 2GC appear to be equally efficacious as UTI prophylaxis in children, the latter exert a broader effect on patients' flora and development of bacterial resistance, suggesting that SXT may be more appropriate for UTI prophylaxis than 2GC.


Subject(s)
Anti-Infective Agents, Urinary/therapeutic use , Cephalosporins/therapeutic use , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Urinary Tract Infections/prevention & control , Child, Preschool , Cross-Over Studies , Drug Resistance, Bacterial , Female , Humans , Infant , Infant, Newborn , Male , Microbial Sensitivity Tests , Prospective Studies , Treatment Outcome , Urinary Tract Infections/urine
14.
Antimicrob Agents Chemother ; 60(5): 2718-26, 2016 05.
Article in English | MEDLINE | ID: mdl-26883703

ABSTRACT

We studied the pharmacokinetics and efficacy of the broad-spectrum triazole isavuconazole for the treatment of experimental invasive pulmonary aspergillosis (IPA) in persistently neutropenic rabbits. Treatment started 24 h after endotracheal administration of Aspergillus fumigatus inoculum; study subjects included rabbits receiving orally administered prodrug isavuconazonium sulfate (BAL8557) equivalent to active moiety isavuconazole (ISA; BAL4815) at 20 (ISA20), 40 (ISA40), and 60 (ISA60) mg/kg (of body weight)/day, with an initial loading dose of 90 mg/kg (ISA90), and untreated rabbits (UC). There were significant concentration-dependent reductions of residual fungal burden (log CFU/gram) and of organism-mediated pulmonary injury, lung weights, and pulmonary infarct scores in ISA40- and ISA60-treated rabbits in comparison to those of UC (P < 0.001). ISA20-treated (P < 0.05), ISA40-treated, and ISA60-treated (P < 0.001) rabbits demonstrated significantly prolonged survival in comparison to that of UC. ISA40- and ISA60-treated animals demonstrated a significant decline of serum (1→3)-ß-d-glucan levels (P < 0.05) and galactomannan indices (GMIs) during therapy following day 4 in comparison to progressive GMIs of UC (P < 0.01). There also were significantly lower concentration-dependent GMIs in bronchoalveolar lavage (BAL) fluid from ISA40- and ISA60-treated rabbits (P < 0.001). There was a direct correlation between isavuconazole plasma area under the concentration-time curve from 0 to 24 h (AUC0-24) and residual fungal burdens in lung tissues, pulmonary infarct scores, and total lung weights. In summary, rabbits treated with isavuconazole at 40 and 60 mg/kg/day demonstrated significant dose-dependent reduction of residual fungal burden, decreased pulmonary injury, prolonged survival, lower GMIs in serum and BAL fluid, and lower serum (1→3)-ß-d-glucan levels.


Subject(s)
Invasive Pulmonary Aspergillosis/drug therapy , Nitriles/therapeutic use , Pyridines/therapeutic use , Triazoles/therapeutic use , Animals , Antifungal Agents/therapeutic use , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/pathogenicity , Bronchoalveolar Lavage Fluid , Female , Galactose/analogs & derivatives , Mannans/therapeutic use , Nitriles/pharmacokinetics , Pyridines/pharmacokinetics , Rabbits , Triazoles/pharmacokinetics
15.
J Antimicrob Chemother ; 71(3): 635-40, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26668236

ABSTRACT

BACKGROUND: Little is known about the effects of fluconazole on the metabolism of Candida albicans. We performed LC/MS-based metabolomic profiling of the response of C. albicans cells to increasing doses of fluconazole. METHODS: C. albicans cells were cultured to mid-logarithmic growth phase in liquid medium and then inoculated in replicate on to nitrocellulose filters under vacuum filtration. Organisms were cultured to mid-logarithmic growth phase and treated with 0-4 mg/L fluconazole. Following metabolic quenching at mid-logarithmic growth phase, intracellular metabolites were extracted and analysed by LC/MS. Changes in pool sizes of individual metabolites were verified by Student's t-test, adjusted for multiple hypothesis testing by Benjamini-Hochberg correction. Distribution of metabolites was analysed by the Kyoto Encyclopedia of Genes and Genomes metabolic pathways database. RESULTS: We reproducibly detected 64 metabolites whose identities were confirmed by comparison against a pure standard and a library of accurate mass-retention time pairs. These 64 metabolites were broadly representative of eukaryotic central metabolic pathways. Among them 12 had their mean abundance significantly altered in response to increasing fluconazole concentrations. Pool sizes of four intermediates of central carbon metabolism (α-ketoglutarate, glucose-6-phosphate, phenylpyruvate and ribose-5-phosphate) and mevalonate were increased by 0.5-1.5-fold (P ≤ 0.05). Five amino acids (glycine, proline, tryptophan, aminoisobutanoate and asparagine) and guanine were decreased by 0.5-0.75-fold (P ≤ 0.05). CONCLUSIONS: Fluconazole treatment of C. albicans resulted in increased central carbon and decreased amino acid synthesis intermediates, suggesting a rerouting of metabolic pathways. The function of these metabolomic changes remains to be elucidated; however, they may represent previously unrecognized mechanisms of metabolic injury induced by fluconazole against C. albicans.


Subject(s)
Antifungal Agents/metabolism , Candida albicans/drug effects , Candida albicans/metabolism , Fluconazole/metabolism , Metabolome/drug effects , Amino Acids/metabolism , Carbon/metabolism , Chromatography, Liquid , Mass Spectrometry , Metabolic Networks and Pathways/drug effects
17.
Clin Infect Dis ; 61 Suppl 6: S622-9, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26567280

ABSTRACT

Biofilm-related infections have become an increasingly important clinical problem. Many of these infections occur in patients with multiple comorbidities or with impaired immunity. Echinocandins (caspofungin, micafungin, and anidulafungin) exert their fungicidal activity by inhibition of the synthesis of the (1→3)-ß-d-glucan. They are active among in vitro and in vivo model systems against a number of Candida species and filamentous fungi in their planktonic and biofilm phenotype. Their superior activity against biofilms poses them in an advantageous position among the antifungal armamentarium. However, additional studies are warranted to expand our knowledge on the role of echinocandins against biofilm-related infections.


Subject(s)
Antifungal Agents/therapeutic use , Biofilms/drug effects , Catheter-Related Infections/drug therapy , Echinocandins/therapeutic use , Fungi/drug effects , Mucous Membrane/microbiology , Mycoses/drug therapy , Anidulafungin , Animals , Candida/drug effects , Candidiasis/drug therapy , Candidiasis/microbiology , Catheter-Related Infections/immunology , Catheter-Related Infections/microbiology , Disease Models, Animal , Echinocandins/chemistry , Echinocandins/metabolism , Humans , Immunomodulation , Microbial Sensitivity Tests , Mycoses/immunology , Mycoses/microbiology
18.
Microbiol Spectr ; 3(3)2015 Jun.
Article in English | MEDLINE | ID: mdl-26185085

ABSTRACT

The steps involved during the biofilm growth cycle include attachment to a substrate followed by more permanent adherence of the microorganisms, microcolony arrangement, and cell detachment required for the dissemination of single or clustered cells to other organ systems. Various methods have been developed for biofilm detection and quantitation. Biofilm-producing microorganisms can be detected in tissue culture plates, using silicone tubes and staining methods, and by visual assessment using scanning electron microscopy or confocal scanning laser microscopy. Quantitative measurement of biofilm growth is determined by using methods that include dry cell weight assays, colony-forming-unit counting, DNA quantification, or XTT 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide reduction assay. Upon infection, innate immune defense strategies are able to establish an immediate response through effector mechanisms mediated by immune cells, receptors, and several humoral factors. We present an overview of the life cycle of biofilms and their diversity, detection methods for biofilm development, and host immune responses to pathogens. We then focus on current concepts in bacterial and fungal biofilm immune evasion mechanisms. This appears to be of particular importance because the use of host immune responses may represent a novel therapeutic approach against biofilms.


Subject(s)
Bacteria/immunology , Biofilms/growth & development , Fungi/immunology , Immune Evasion/immunology , Animals , Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Bacteria/drug effects , Bacteria/pathogenicity , Biofilms/drug effects , Colony Count, Microbial , Fungi/drug effects , Fungi/pathogenicity , Humans
19.
J Antimicrob Chemother ; 70(2): 470-8, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25288679

ABSTRACT

OBJECTIVES: Biofilm formation by Candida albicans poses an important therapeutic challenge in human diseases. Typically, conventional antifungal agents encounter difficulty in treating and fully eradicating biofilm-related infections. Novel therapeutic approaches are needed to treat recalcitrant Candida biofilms. Farnesol is a quorum-sensing molecule, which induces apoptosis, inhibits Ras protein pathways and profoundly affects the morphogenesis of C. albicans. We therefore investigated the interactions between farnesol and different classes of antifungal agents. METHODS: The combined antifungal effects of triazoles (fluconazole), polyenes (amphotericin B) and echinocandins (micafungin) with farnesol against C. albicans biofilms were assessed in vitro. Antifungal activity was determined by the XTT metabolic assay and confocal microscopy. The nature and the intensity of the interactions were assessed using the Loewe additivity model [fractional inhibitory concentration (FIC) index] and the Bliss independence (BI) model. RESULTS: Significant synergy was found between each of the three antifungal agents and farnesol, while antagonism was not observed for any of the combinations tested. The greatest synergistic effect was found with the farnesol/micafungin combination, for which the BI-based model showed the observed effects as being 39%-52% higher than expected if the drugs had been acting independently. The FIC indices ranged from 0.49 to 0.79, indicating synergism for farnesol/micafungin and farnesol/fluconazole and no interaction for farnesol/amphotericin B. Structural changes in the biofilm correlated well with the efficacies of these combinations. The maximum combined effect was dependent on the farnesol concentration for micafungin and amphotericin B. CONCLUSIONS: Farnesol exerts a synergistic or additive interaction with micafungin, fluconazole and amphotericin B against C. albicans biofilms, thus warranting further in vivo study.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Biofilms/drug effects , Candida albicans/drug effects , Candida albicans/physiology , Farnesol/pharmacology , Fluconazole/pharmacology , Dose-Response Relationship, Drug , Drug Interactions , Humans , Microbial Sensitivity Tests , Microscopy, Confocal
20.
Eur J Pediatr ; 174(1): 65-74, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24985124

ABSTRACT

UNLABELLED: The investigation and successful management of a monoclonal Acinetobacter baumannii outbreak in a neonatal intensive care unit are described. Upon the first clustered carbapenem-resistant A. baumannii (CRAB) infections, a bundle of actions were taken, including enhanced infection control, active surveillance (weekly stool samples), case-control study, staff education, daily audits and discontinuation of new admissions. Between September and December 2011, eight neonates developed 10 CRAB infections (five blood, four respiratory and one eye). A total of 216 active surveillance cultures were obtained from 96 neonates (43 % had ≥2 samples). During weeks 12, 16 and 17, active surveillance detected 3, 1 and 2 new CRAB acquisitions, respectively. Prevalence of infections/colonizations decreased, and no event occurred after 20th week. A colonized neonate developed CRAB sepsis and died. All CRAB isolates harboured bla OXA-58 and the intrinsic chromosomal bla OXA-51 carbapenemase genes. CONCLUSION: Active surveillance and enhanced infection control measures effectively contained spread of CRAB clone in the neonatal intensive care unit.


Subject(s)
Acinetobacter Infections/drug therapy , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/isolation & purification , Disease Outbreaks , beta-Lactam Resistance , Acinetobacter Infections/microbiology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/therapeutic use , Carbapenems/adverse effects , Colistin/therapeutic use , Feces/microbiology , Humans , Infant, Newborn , Intensive Care Units, Neonatal , Meropenem , Prospective Studies , Thienamycins/therapeutic use , beta-Lactamases/genetics
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