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Competing Interests: The authors have no funding or conflicts of interest to disclose.

The pandemic marked the beginning of an era of dynamic and rapid changes in the diagnosis of respiratory infections. Herein we describe Legionnaires' disease trend in the years 2016-2023 in a large Italian hospital showing how improvements in diagnostic algorithms impact on its detection., (© 2024. The Author(s).)

Competing Interests: We declare no competing interests. MM, MLS, ACh, and BP contributed equally to this work. MS acknowledges EU funding for the MUR PNRR Extended Partnership initiative on Emerging Infectious Diseases (Project number PE00000007, INF-ACT). This study was designed by MM, MLS, FDM, and AG. Data collection was performed by VP and ACa. Data analysis and figure preparation were performed by FDM, RR, and BF. MM and FDM wrote the paper. MS, ACh, and BP revised the manuscript. All authors participated in the discussion and interpretation of the results. All authors have read and agreed to the published version of the manuscript. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Immediate hypersensitivity reactions (iHSRs) to taxanes are observed in 6% and 4% of gynecologic and breast cancer patients, respectively. Drug desensitization is the only option, as no comparable alternative therapy is available. Surfactants in the taxane formulation have been implicated in the immunopathogenesis of iHSRs, although sporadic skin test (ST) positivity and iHSRs to nab-paclitaxel have suggested the involvement of the taxane moiety and/or IgE-mediated pathomechanisms. In vitro diagnostic tests might offer insights into mechanisms underlying iHSRs to taxanes. The aim of the present study was to address this unmet need by developing a novel basophil activation test (BAT). The study included patients ( n = 31) undergoing paclitaxel/carboplatin therapy. Seventeen patients presented with iHSRs to paclitaxel (iHSR-Tax pos ), and eleven were tolerant (iHSR-Tax neg ). Fourteen patients presented with iHSRs to carboplatin (iHSR-Pl pos ), and fourteen were tolerant (iHSR-Pl neg ). The BAT median stimulation index (SI) values were 1.563 (range, 0.02-4.11; n = 11) and -0.28 (range -4.88-0.07, n = 11) in iHSR-Tax pos and iHSR-Tax neg , respectively. The BAT median SI values were 4.45 (range, 0.1-26.7; n = 14) and 0 (range, -0.51-1.65; n = 12) in iHSR-Pl pos and iHSR-Pl neg , respectively. SI levels were not associated with iHSR severity grading. Comparing BAT results in iHSR-Tax pos and iHSR-Tax neg showed the area under the receiver operator characteristic (ROC) curve to be 0.9752 ( p = 0.0002). The cutoff calculated by the maximized likelihood ratio identified 90.91% of iHSR-Tax pos patients and 90.91% of iHSR-Tax neg patients. Comparing BAT results for iHSR-Pl pos and iHSR-Pl neg showed the area under the ROC curve to be 0.9286 ( p = 0.0002). The cutoff calculated by the maximized likelihood ratio identified 78.57% of iHSR-Pl pos patients and 91.67% of iHSR-Pl neg patients. Most iHSR-Tax pos patients for which ST was available (10/11) scored ST-negative and BAT-positive, whereas most iHSR-Pl pos patients for which ST was available (14/14) scored both BAT- and ST-positive. This suggested the intervention of non-IgE-mediated mechanisms in iHSR-Tax pos patients. Consistent with this view, an in silico molecular docking analysis predicted the high affinity of paclitaxel to the degranulation-competent MRGPRX2 receptor. This hypothesis warrants further in vitro investigations. In conclusion, the present study provides preliminary proof-of-concept evidence that this novel BAT has potential utility in understanding mechanisms underlying iHSRs to taxanes.

Background: Etiology of allergic rhinitis and asthma is frequently associated with house dust mite sensitization and allergen immunotherapy (AIT) represents the only disease modifying treatment. In a real world setting, clinicians would benefit from biomarkers to monitor or predict response to AIT., Methods: Twenty-four consecutive house dust mite (HDM) mono-sensitized rhinitic patients, treated with subcutaneous immunotherapy (SCIT) as per clinical practice, were enrolled. Multiple in vitro biomarkers such as basophil activation (BAT), IL-10 levels, and molecular allergen-specific IgE were performed during HDM SCIT, to monitor the effects of AIT and then correlated to in vivo scores (VAS, CMSS, RQLQ). Nasal cytology was performed at baseline and after 6 and 12 months of treatment. Finally, the economic impact of SCIT in this cohort of patients was evaluated., Results: Clinical biomarkers confirmed to be useful to monitor AIT efficacy. As for laboratory biomarkers, BAT showed a reduction trend, particularly for D2C1, suggesting that this is a useful parameter in monitoring patients. IL-10 levels tend to remain stable or slightly decrease during treatment. The economic analysis confirmed the favorable impact of immunotherapy., Conclusions: In this cohort of patients, SCIT confirmed its effectiveness in reducing symptoms and drug utilization. Clinical scores confirmed to be valid in monitoring patients and their response. BAT demonstrated to be useful in monitoring more than predicting response. Further studies are needed to better explore the usefulness of these biomarkers in AIT., (© 2023 The Authors.)

Bacterial pneumonia is a challenging coronavirus disease 2019 (COVID-19) complication for intensive care unit (ICU) clinicians. Upon its implementation, the FilmArray pneumonia plus (FA-PP) panel's practicability for both the diagnosis and antimicrobial therapy management of bacterial pneumonia was assessed in ICU patients with COVID-19. Respiratory samples were collected from patients who were mechanically ventilated at the time bacterial etiology and antimicrobial resistance were determined using both standard-of-care (culture and antimicrobial susceptibility testing [AST]) and FA-PP panel testing methods. Changes to targeted and/or appropriate antimicrobial therapy were reviewed. We tested 212 samples from 150 patients suspected of bacterial pneumonia. Etiologically, 120 samples were positive by both methods, two samples were culture positive but FA-PP negative (i.e., negative for on-panel organisms), and 90 were negative by both methods. FA-PP detected no culture-growing organisms (mostly Staphylococcus aureus or Pseudomonas aeruginosa) in 19 of 120 samples or antimicrobial resistance genes in two culture-negative samples for S. aureus organisms. Fifty-nine (27.8%) of 212 samples were from empirically treated patients. Antibiotics were discontinued in 5 (33.3%) of 15 patients with FA-PP-negative samples and were escalated/deescalated in 39 (88.6%) of 44 patients with FA-PP-positive samples. Overall, antibiotics were initiated in 87 (72.5%) of 120 pneumonia episodes and were not administered in 80 (87.0%) of 92 nonpneumonia episodes. Antimicrobial-resistant organisms caused 78 (60.0%) of 120 episodes. Excluding 19 colistin-resistant Acinetobacter baumannii episodes, AST confirmed appropriate antibiotic receipt in 101 (84.2%) of 120 episodes for one or more FA-PP-detected organisms. Compared to standard-of-care testing, the FA-PP panel may be of great value in the management of COVID-19 patients at risk of developing bacterial pneumonia in the ICU. IMPORTANCE Since bacterial pneumonia is relatively frequent, suspicion of it in COVID-19 patients may prompt ICU clinicians to overuse (broad-spectrum) antibiotics, particularly when empirical antibiotics do not cover the suspected pathogen. We showed that a PCR-based, culture-independent laboratory assay allows not only accurate diagnosis but also streamlining of antimicrobial therapy for bacterial pneumonia episodes. We report on the actual implementation of rapid diagnostics and its real-life impact on patient treatment, which is a gain over previously published studies on the topic. A better understanding of the role of that or similar PCR assays in routine ICU practice may lead us to appreciate the effectiveness of their implementation during the COVID-19 pandemic.

Background: The basophil activation test (BAT) is used to improve the accuracy of food allergy diagnosis. To date, the influence of antiallergic drugs on BAT reactivity is poorly investigated. The aim of the study was to investigate if BAT results were influenced by antihistamine intake for 3 months in a cohort of patients with IgE-mediated food allergy to milk or egg., Methods: A retrospective, single-center, observational study was performed. We enrolled subjects with history of hypersensitivity reaction after specific food ingestion, positive skin prick tests and specific IgEs, concomitant allergic rhinitis, and, contraindication to the double-blind, placebo-controlled food challenge due to personal history of systemic reactions related to the ingestion of culprit food. Validated allergens (α-lactoalbumin, β-lactoglobulin, casein, egg white, and yolk) for BAT were used., Results: Thirty-nine patients with well-documented food symptoms and positive allergological workup were included in the study. BAT was positive in 29 patients. The mean percentages of CD63+ expression to specific culprit allergen did not change after the administration of drugs., Conclusions: This was the first study assessing the effects of oral antihistamines on basophil reactivity in cow's milk and egg food allergy. Antihistamines do not interfere with BAT results.

A low count of CD4 + and CD8 + lymphocytes is a hallmark laboratory finding in the coronavirus disease 2019 (COVID-19). Using flow cytometry, we observed significantly higher CD95 (Fas) and PD-1 expression on both CD4 + T and CD8 + T cells in 42 COVID-19 patients when compared to controls. Higher CD95 expression in CD4 + cells correlated with lower CD4 + counts. A higher expression of CD95 in CD4 + and CD8 + lymphocytes correlated with a lower percentage of naive events. Our results might suggest a shift to antigen-activated T cells, expressing molecules increasing their propensity to apoptosis and exhaustion during COVID-19 infection., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Purpose: Whether subglottic secretions (SS) culture during invasive mechanical ventilation may aid microbiological surveillance is unknown. We conducted a prospective study to assess SS cultures predictivity of endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) isolates., Materials and Methods: 109 patients receiving mechanical ventilation for ≥48 hours underwent SS and ETA surveillance cultures twice weekly; blind BAL was performed in case of clinically suspected pneumonia., Results: SS and ETA cultures were fully concordant in 170 (81%-overall accuracy) of 211 sample pairs. As compared to ETA, SS culture global sensitivity and specificity were 84% [95%CI: 77 to 91] and 74% [95%CI: 66 to 82]; negative and positive predictive values were 82% and 77%. Forty-four episodes of clinically suspected pneumonia were observed. Compared to BAL, SS culture global sensitivity and specificity were 68% [95%CI: 45 to 81] and 63% [95%CI: 44 to 82]; negative and positive predictive values were both 65%. SS sensitivity, specificity, positive and negative predictive values in anticipating BAL isolates were comparable to ETA (all p > 0.20)., Conclusions: SS cultures show worthy accuracy in identifying ETA isolates, with excellent sensitivity and good negative predictivity. SS cultures may be not inferior to ETA in predicting BAL results in case of ventilator-associated pneumonia., Trial Registration: ClinicalTrials.gov, NCT03153241. Registered on 15 May 2017, https://clinicaltrials.gov/ct2/show/NCT03153241., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We report pertussis cases in 4 infants less than 6 months admitted with symptoms compatible with pertussis to the intensive care unit of the Università Cattolica del Sacro Cuore in Rome, April 2014. Realtime PCR confirmed pertussis diagnosis for the 4 infants, 2 of them were cousins, and for the household contacts of 1 of them. Analysis of pertussis toxin, its promoter and pertactin was also performed. First of all, this report emphasizes the need to investigate household contact of infants with pertussis; secondly, to evaluate the selective vaccination of household members of newborns as an effective program to reduce pertussis in infants.

Methionine sulfoxide reductases A and B are antioxidant repair enzymes that reduce the S- and R-diastereomers of methionine sulfoxides back to methionine, respectively. Enterococcus faecalis, an important nosocomial pathogen, has one msrA gene and one msrB gene situated in different parts of the chromosome. Promoters have been mapped and mutants have been constructed in two E. faecalis strains (strains JH2-2 and V583) and characterized. For both backgrounds, the mutants are more sensitive than the wild-type parents to exposure to H2O2, and in combination the mutations seem to be additive. The virulence of the mutants has been analyzed in four different models. Survival of the mutants inside mouse peritoneal macrophages stimulated with recombinant gamma interferon plus lipopolysaccharide but not in naïve phagocytes is significantly affected. The msrA mutant is attenuated in the Galleria mellonella insect model. Deficiency in either Msr enzyme reduced the level of virulence in a systemic and urinary tract infection model. Virulence was reconstituted in the complemented strains. The combined results show that Msr repair enzymes are important for the oxidative stress response, macrophage survival, and persistent infection with E. faecalis.

Background: Candida colonization is an important predictor for development of invasive fungal infection (IFI). We investigated whether early detection of Candida mannan (Mn) in bronchoalveolar lavage fluid (BALF) reduces IFI among preterm infants., Methods: We conducted an observational study of infants with gestational age of < or =28 weeks, where a group undergoing Candida surveillance cultures (pre-Mn detection group) was compared with a group defined after the initiation of routine use of Candida Mn detection in BALF (Mn detection group). Antifungal treatment was started based on positive microbiologic (surveillance culture or Mn-antigen assay) results., Results: No significant differences were detected when the groups were compared for several predictors of IFI. IFI was observed for 12 (23%) of 51 infants in the pre-Mn detection group, and for 0 (0%) of 29 infants in the Mn detection group (P = 0.003). Surveillance cultures in the pre-Mn detection group became positive at 15.0 +/- 7.2 days after birth, whereas the mean age at time of positive Mn antigen results in the Mn detection group was 4.3 +/- 3.1 days (P < 0.0001). Among 16 infants positive for surveillance cultures, 12 (75%) developed IFI (P < 0.0001)., Conclusions: This study suggests that Candida Mn detection in BALF may be useful for earlier identification and preemptive therapy targeting preterm infants at high risk of IFI.

The oligopeptide transport systems Opp belong to the nickel/peptide/opine PepT subfamily of ABC-transporters. The opportunist pathogen Staphylococcus aureus encodes four putative Opps and one orphean substrate binding protein Opp5A. Here, we report that the Opp2 permease complex (Opp2BCDF) and Opp5A are involved in nickel uptake and then renamed them NikBCDE and NikA respectively. S. aureus carries also a high-affinity nickel transporter NixA belonging to the NiCoT family of secondary transporters. The activity of these two nickel transporters determine that of urease, a multimeric nickel-dependent enzyme mainly involved in the neutralization of acidic environments. However, only the Nik system was responsible for the neutralization and deposit of pH-dependent crystals in human urine. Inactivation of the nik genes affected bacterial colonization of mouse urinary tract, as well as the 50% infective dose levels compared with the parental and nixA strains. Finally, complementation of the nik mutations restored bacterial colonization. Together, our results suggest a role for the Nik system in the urinary tract infection by S. aureus, probably due to the urease-mediated pH increase of the urine., (© 2010 Blackwell Publishing Ltd.)

The Vitek 2 yeast susceptibility test was evaluated by testing 122 Candida isolates against fluconazole and voriconazole. Excellent categorical agreement with the CLSI broth microdilution method was observed (97.5% for both the azoles). Moreover, the Vitek 2 system was able to identify all but 2 of 59 investigated fluconazole-resistant organisms.

Candida surveillance cultures were obtained from 51 neonatal intensive care unit patients. Sixteen infants showing positive cultures developed subsequent Candida infection, whereas it did not occur for the 35 infants with negative cultures. Fifteen of 16 infants (<1000 g) had <27 weeks of gestational age. Antifungal treatment was started at the time colonization was detected; only 1 infant died of Candida infection.

Background: The role of Candida glabrata in fungaemia is attributed in part to its reduced susceptibility to azoles, usually due to altered expression of genes encoding drug efflux pumps. The aims of this study were to identify risk factors for fungaemia due to C. glabrata isolates with decreased susceptibility to fluconazole and to analyse the response to antifungal treatment and the clinical outcome of C. glabrata infections in hospitalized patients., Methods: A retrospective case-case-control study was conducted at a university hospital from 2000 to 2006. Three patient groups were studied: 14 patients infected by a fluconazole-less-susceptible isolate [susceptible-dose-dependent (SDD) or resistant]; 21 patients infected by a fluconazole-susceptible (FS) isolate; and 70 uninfected controls. We measured expression of the drug efflux pump-encoding CgCDR1 and CgCDR2 genes in isolates of the two infected groups using quantitative real-time PCR., Results: Multivariable analysis found that patients with prior fluconazole use [odds ratio (OR) 12.24, 95% confidence intervals (CIs) 1.77-84.39, P = 0.01], diabetes (OR 10.47, 95% CI 1.96-55.96, P = 0.006) and a central venous catheter (CVC) (OR 8.48, 95% CI 1.82-39.36, P = 0.006) were more likely to develop fungaemia due to a less-susceptible isolate. Previous surgery (OR 7.73, 95% CI 2.18-27.41, P = 0.002) was an independent risk factor for fungaemia due to a susceptible isolate, in addition to the presence of a CVC (OR 5.48, 95% CI 1.69-17.72, P = 0.004). The crude 30 day mortality rate was high for both case groups. Seven patients received inadequate antifungal treatment, including five infected by a fluconazole-resistant isolate but empirically treated with fluconazole; six of these seven patients died. Expression of the CgCDR genes was up-regulated in all fluconazole-resistant and, to a lesser extent, SDD isolates, but not in the FS isolates., Conclusions: Our data suggest that when candidaemia is suspected or detected, a more broad-spectrum antifungal drug (i.e. echinocandins or amphotericin B) should be considered as initial treatment for patients with prior azole exposure.

Our previous investigation on Candida glabrata azole-resistant isolates identified two isolates with unaltered expression of CgCDR1/CgCDR2, but with upregulation of another ATP-binding cassette transporter, CgSNQ2, which is a gene highly similar to ScSNQ2 from Saccharomyces cerevisiae. One of the two isolates (BPY55) was used here to elucidate this phenomenon. Disruption of CgSNQ2 in BPY55 decreased azole resistance, whereas reintroduction of the gene in a CgSNQ2 deletion mutant fully reversed this effect. Expression of CgSNQ2 in a S. cerevisiae strain lacking PDR5 mediated not only resistance to azoles but also to 4-nitroquinoline N-oxide, which is a ScSNQ2-specific substrate. A putative gain-of-function mutation, P822L, was identified in CgPDR1 from BPY55. Disruption of CgPDR1 in BPY55 conferred enhanced azole susceptibility and eliminated CgSNQ2 expression, whereas introduction of the mutated allele in a susceptible strain where CgPDR1 had been disrupted conferred azole resistance and CgSNQ2 upregulation, indicating that CgSNQ2 was controlled by CgPDR1. Finally, CgSNQ2 was shown to be involved in the in vivo response to fluconazole. Together, our data first demonstrate that CgSNQ2 contributes to the development of CgPDR1-dependent azole resistance in C. glabrata. The overlapping in function and regulation between CgSNQ2 and ScSNQ2 further highlight the relationship between S. cerevisiae and C. glabrata.

Nosocomial Candida bloodstream infections rank among infections with highest mortality rates. A retrospective cohort analysis was conducted at Catholic University Hospital to estimate the risk factors for mortality of patients with candidemia. We reviewed records for patients with a Candida bloodstream infection over a 5-year period (January 2000 through December 2004). Two hundred ninety-four patients (42.1% male; mean age +/- standard deviation, 65 +/- 12 years) were studied. Patients most commonly were admitted with a surgical diagnosis (162 patients [55.1%]), had a central venous catheter (213 [72.4%]), cancer (118 [40.1%]), or diabetes (58 [19.7%]). One hundred fifty-four (52.3%) patients died within 30 days. Of 294 patients, 168 (57.1%) were infected by Candida albicans, 64 (21.7%) by Candida parapsilosis, 28 (9.5%) by Candida tropicalis, and 26 (8.8%) by Candida glabrata. When fungal isolates were tested for biofilm formation capacity, biofilm production was most commonly observed for isolates of C. tropicalis (20 of 28 patients [71.4%]), followed by C. glabrata (6 of 26 [23.1%]), C. albicans (38 of 168 [22.6%]), and C. parapsilosis (14 of 64 [21.8%]). Multivariable analysis identified inadequate antifungal therapy (odds ratio [OR], 2.35; 95% confidence interval [95% CI], 1.09 to 5.10; P = 0.03), infection with overall biofilm-forming Candida species (OR, 2.33; 95% CI, 1.26 to 4.30; P = 0.007), and Acute Physiology and Chronic Health Evaluation III scores (OR, 1.03; 95% CI, 1.01 to 1.15; P < 0.001) as independent predictors of mortality. Notably, if mortality was analyzed according to the different biofilm-forming Candida species studied, only infections caused by C. albicans (P < 0.001) and C. parapsilosis (P = 0.003) correlated with increased mortality. Together with well-established factors, Candida biofilm production was therefore shown to be associated with greater mortality of patients with candidemia, probably by preventing complete organism eradication from the blood.

A total of 750 clinical yeast isolates were evaluated by two identification systems, VITEK 2 and RapID Yeast Plus, using sequence analysis of the rRNA gene internal transcribed spacer regions as the reference method. The VITEK 2 and RapID systems correctly identified 737 (98.2%) and 716 (95.5%) isolates, respectively.

Objectives: Several studies have documented the potent in vitro activity of caspofungin against Candida spp. This is of special concern for Candida glabrata infections that are often resistant to many azole antifungal agents and, consequently, difficult to treat. The aim of the present study was to expand the data on the in vitro activity of caspofungin against azole-resistant isolates of C. glabrata., Methods: A total of 50 clinical isolates of C. glabrata were tested for susceptibility to caspofungin. The isolates were cross-resistant to multiple azoles, including fluconazole, itraconazole, ketoconazole and voriconazole. Expression of the resistance-related CgCDR1 and CgCDR2 genes was evaluated by quantitative RT-PCR analysis. The MICs of caspofungin were determined by using the National Committee for Clinical Laboratory Standards M27-A2 reference method., Results: C. glabrata isolates exhibited increased expression of the CDR efflux pump(s), and this was in accordance with their high-level azole resistance. In contrast, all the isolates were highly susceptible to caspofungin (100% of isolates were inhibited at

We describe a case of recurrent Candida glabrata fungemia that became unresponsive to fluconazole treatment. Posttreatment isolates from blood and vaginal cultures of the immunocompetent patient were azole resistant and exhibited upregulated expression of CgCDR1/CgCDR2 efflux pumps compared to the original isolates. Amphotericin B therapy eradicated the infection.

We have recently demonstrated that upregulation of the ATP binding cassette (ABC) transporter-encoding gene AFR1 in Cryptococcus neoformans is involved in the in vitro resistance to fluconazole of this yeast. In the present study, we investigated the role of AFR1 in the in vivo response to fluconazole in a mouse model of systemic cryptococcosis. Mice were infected with a wild-type fluconazole-susceptible strain of C. neoformans, strain BPY22; an afr1 mutant, BPY444, which displayed hypersusceptibility to fluconazole in vitro; or an AFR1-overexpressing strain, BPY445, which exhibited in vitro resistance to the drug. In each of the three groups, infected animals were randomly assigned to fluconazole treatment or untreated-control subgroups. As expected, fluconazole prolonged survival and reduced fungal tissue burdens (compared with no treatment) in BPY22- and BPY444-infected mice, whereas it had no significant effects in mice infected with BPY445. When the pathogenicities of these strains in mice were investigated, strain BPY445 was significantly more virulent than BPY22 following inhalational or intravenous inoculation, but mice infected with BPY444 survived significantly longer than BPY22-infected animals only when infection was acquired via the respiratory tract. In in vitro macrophage infection studies, strain BPY445 also displayed enhanced intracellular survival compared with strains BPY22 and BPY444, suggesting that its increased virulence may be due to its reduced vulnerability to the antimicrobial factors produced by phagocytic cells. These findings indicate that the upregulation of the AFR1 gene is an important factor in either determining the in vivo resistance to fluconazole or influencing the virulence of C. neoformans.

An iCycler iQ real-time PCR assay targeting 18S rRNA Aspergillus-specific sequences was developed for the diagnosis of invasive pulmonary aspergillosis (IPA). Positive findings were obtained for 18 of 20 (90%) bronchoalveolar lavage (BAL) fluid specimens from patients with probable or confirmed IPA and were obtained for none of the 24 BAL samples from patients with no clinical evidence of aspergillosis. These results were concordant with those of a nested PCR assay, which detected 90% of the patients with IPA, while galactomannan ELISA revealed positivity for 100% of these patients, suggesting that combined use of methods might improve the diagnosis of IPA.

Resistance to fluconazole is a possible event during prolonged suppressive drug therapy for cryptococ-cal meningitis, the most frequently encountered life-threatening manifestation of cryptococcosis. The knowledge of this resistance at the molecular level is important for management of cryptococcosis. In order to identify genes involved in azole resistance in Cryptococcus neoformans, a cDNA subtraction library technique was chosen as a strategy. First, a fluconazole-resistant mutant BPY22.17 was obtained from a susceptible clinical isolate BPY22 by in vitro exposure to the drug. Then, a subtractive hybridization procedure was used to compare gene expression between the obtained strains. We identified a cDNA overexpressed in the fluconazole-resistant strain BPY22.17 that was used as a probe to isolate the entire gene in a C. neoformans genomic library. Sequence analysis of this gene identified an ATP Binding Cassette (ABC) transporter-encoding gene called C. neoformans AntiFungal Resistance 1 (CnAFR1). Disruption of CnAFR1 gene in the resistant isolate (BPY22.17) resulted in an enhanced susceptibility of the knock-out mutant cnafr1 against fluconazole, whereas reintroduction of the gene in cnafr1 resulted in restoration of the resistance phenotype, thus confirming that CnAFR1 is involved in fluconazole resistance of C. neoformans. Our findings therefore reveal that an active drug efflux mechanism can be involved in the development of azole resistance in this important human pathogen.

We describe an outbreak of Candida albicans systemic infection involving five premature infants in a neonatal intensive care unit. Molecular and epidemiologic characterization of all C. albicans isolates was performed by DNA fingerprinting with the 27A probe. This genotypic analysis demonstrated that the isolates were identical, providing evidence for the circulation of a unique C. albicans strain.

We report a case of fatal pulmonary infection caused by Mycobacterium abscessus in a young patient with cystic fibrosis, who underwent bipulmonary transplantation after a 1-year history of severe lung disease. Fifteen days after surgery he developed septic fever with progressive deterioration in lung function. M. abscessus, initially isolated from a pleural fluid specimen, was then recovered from repeated blood samples, suggesting a disseminated nature of the mycobacterial disease. Drug susceptibility testing assay, performed on two sequential isolates of the microorganism, showed a pattern of multidrug resistance. Despite aggressive therapy with several antimycobacterial drugs, including clarithromycin, the infection persisted, and the patient died.