ABSTRACT
Invasive pulmonary mold disease (IPMD) is often fatal in neutropenic patients. This is because IPMD is difficult to diagnose timely, especially when non-Aspergillus molds are the causative agent, as they are usually not associated with a positive galactomannan assay. In 2013 we showed that exhaled breath analysis might be used to diagnose invasive aspergillosis through profiling of patterns in exhaled volatile organic compounds (VOCs) by electronic nose (eNose) technology. The current study aimed to determine (1) whether molds can be discriminated from other microorganisms (using two mold species: Aspergillus fumigatus and a pathogenic mold not associated with a positive galactomannan assay, i.c. Rhizopus oryzae) and (2) whether both molds can be discriminated from each other. First, we cultured strains of Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, A. fumigatus and R. oryzae in separate airtight bottles. We examined whether an eNose (Cyranose 320) could discriminate the headspaces of bottles with molds from those with bacteria/yeasts. Second, we examined whether an eNose could discriminate A. fumigatus and R. oryzae. Diagnostic algorithms were created using canonical discriminant analysis after principle component analysis. Primary outcome parameter was the validated accuracy. The eNose discriminated A. fumigatus from bacteria/yeasts with a cross-validated accuracy of 92.9% (sensitivity 95.2%, specificity 91.9%). The eNose had an accuracy (validated using split-half analysis) of 100% in discriminating A. fumigatus from R. oryzae. Our study suggests that an eNose can identify and classify molds in vitro. This warrants prospective in vivo studies aimed at detecting and classifying IPMD using exhaled breath.
Subject(s)
Aspergillus fumigatus/isolation & purification , Electronic Nose , Rhizopus/isolation & purification , Algorithms , Breath Tests , Candida albicans/isolation & purification , Discriminant Analysis , Exhalation , Humans , ROC CurveABSTRACT
Given reports of increasing syphilis incidence in Western countries, we used molecular typing and epidemiological data to elucidate Treponema pallidum transmission networks. Samples and data were collected, dating from 2002 to 2005, from a well-defined population of patients with an ulcus and a diagnosis of infectious syphilis. Molecular typing using the tprK gene (V3-V5 region) was performed on 211 isolates from 205 Amsterdam STI clinic patients. We revealed 32 T. pallidum clusters and recognized ten large clusters, consisting predominantly of homosexual men (89%). Yet, no common patient characteristics were found to link the patients in these clusters. We therefore conclude that the highly variable tprK region (V3-V5) is not suitable for elucidating T. pallidum transmission networks in a high risk population.
Subject(s)
Bacterial Proteins/genetics , Bacterial Typing Techniques/methods , Contact Tracing/methods , Porins/genetics , Syphilis/epidemiology , Syphilis/microbiology , Treponema pallidum/classification , Treponema pallidum/genetics , Adult , Cluster Analysis , Female , Genotype , Humans , Male , Middle Aged , Treponema pallidum/isolation & purificationABSTRACT
OBJECTIVE: To report the incidence of gonorrhoea and the development of resistance to Neisseria gonorrhoeae among attendees at the Municipal Health Service's STD-clinic in Amsterdam, The Netherlands, 2000-2003. DESIGN: Descriptive. METHOD: Urethral or cervical swabs for culture for N. gonorrhoea were taken from attendees at the STD-clinic. Depending on reported sexual techniques throat and rectal swabs were also taken. The disk diffusion technique in combination with a beta-lactamase test were used for sensitivity testing. RESULTS. The number of Neisseria gonorrhoeae (NG) isolates collected at the Amsterdam Municipal Health Service's STD-clinic decreased from 1047 in 2002 to 772 in 2003. The number of fluoroquinolone-resistant NG (FRNG) isolates rose from 3 in 2000 to 56 in 2003 (p < 0.001). FRNG isolates amongst men who have sex with men increased from 1 in 568 isolates (0.2%) in 2000 to 50 in 478 isolates (10.5%) in 2003 (p < 0.001). Amongst heterosexual men, FRNG rose from 2 per 275 (0.7%) in 2000 to 16 per 297 (5.4%) in 2002 and dropped to 6 per 190 (3.4%) in 2003 (p = 0.146). No FRNG isolates were found in women in 2003 (2000: 0/180 (0.0%); 2001: 2/160 (1.3%); 2002: 4/183 (2.2%). CONCLUSION: The recent incidence of FRNG among men who have sex with men to over 5% makes ciprofloxacin and other fluoroquinolones obsolete as the first-choice treatment option for uncomplicated gonorrhoea if no antibiogram is available. It is advised to use cefotaxim when an antibiogram is not available (yet).
