Bacteria from the Burkholderia cepacia complex are generally considered to be non-pathogenic to the healthy population. However, some of these species may cause serious nosocomial infections in immunocompromised patients; as such, it is essential to diagnose these infections rapidly so that adequate treatment can be initiated. We report here the use of a radiolabeled siderophore, ornibactin (ORNB), for positron emission tomography imaging. We successfully radiolabeled ORNB with gallium-68 with high radiochemical purity and proved that the resulting complex has optimal in vitro characteristics. In mice, the complex did not show excessive accumulation in organs and was excreted in the urine. We demonstrated that the [68Ga]Ga-ORNB complex accumulates at the site of Burkholderia multivorans infection, including pneumonia, in two animal infection models. These results suggest that [68Ga]Ga-ORNB is a promising tool for the diagnosis, monitoring, and evaluation of the therapeutic response to B. cepacia complex infection.
- MeSH
- Burkholderia cepacia complex * MeSH
- Burkholderia Infections * diagnostic imaging epidemiology MeSH
- Mice MeSH
- Positron-Emission Tomography MeSH
- Gallium Radioisotopes MeSH
- Siderophores MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Streptococcus milleri group (SMG) is a group of three streptococcal species (S. anginosus, intermedius and constellatus) that act as opportunist pathogens, among others in cystic fibrosis. Due to their fastidious character, they are both difficult to cultivate and to differentiate from less pathogenic streptococcal species, therefore being most probably underdiagnosed. Semi-selective McKay agar and NAS agar were developed to facilitate SMG recovery from clinical samples; however, direct comparison of recovery rates has not been published yet. We tested the performance of both media on 123 patient samples and demonstrated general superiority of NAS agar for SMG recovery during primary cultivation convincingly. This observation was also confirmed by quantitative drop tests during subculture. Despite the undisputed overall superiority of NAS agar over McKay agar, a smaller fraction of strains grew better on McKay agar. Inter-strain differences were the most probable explanation. Therefore, when economic conditions are not limiting and maximum recovery rate is desirable, both plates are advised to be used in parallel for primary cultivation of clinical samples.
BACKGROUND AND AIMS: Haemophilus influenzae new strain acquisition has been demonstrated to increase the relative risk of acute exacerbation fourfold in contrast to colonisation or chronic infection by the same strain in chronic obstructive pulmonary disease (COPD). Unfortunately, molecular typing techniques are not suitable for routine use due to cost, labour-intensity and need for special expertise. We tested two techniques potentially useful for routine typing, namely the newly available MALDI-TOF MS and the modified McRAPD compared to MLST as the gold standard. METHODS: In 10 patients (10.8%) suffering from COPD or cystic fibrosis, H. influenzae isolates were recovered repeatedly at different timepoints from the same patient during the study period. This allowed for thirteen pairwise comparisons of typing results in isolates recovered consecutively from the same patient to test the ability of the techniques to uncover new strain acquisition. RESULTS: MLST detected 9 cases of new strain acquisition among the 13 pairwise comparisons. However, MALDI-TOF MS reported all 13 pairs as different and thus new. In contrast, McRAPD was able to differentiate all the new strain acquisitions from pre-existing ones, both by visual inspection of melting profiles and by Relative Significant Difference values. CONCLUSIONS: Unlike MALDI-TOF MS, McRAPD appears to be a suitable candidate for routine discrimination of new strain acquisitions because of its accuracy and, rapid, easy and economic performance.
- MeSH
- Pulmonary Disease, Chronic Obstructive diagnosis MeSH
- Cystic Fibrosis diagnosis MeSH
- Diagnosis, Differential MeSH
- Haemophilus influenzae isolation & purification MeSH
- Haemophilus Infections diagnosis MeSH
- Humans MeSH
- Sensitivity and Specificity MeSH
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods standards MeSH
- Bacterial Typing Techniques methods standards MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
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- Keywords
- prodloužená kultivace,
- MeSH
- Achromobacter isolation & purification MeSH
- Time Factors MeSH
- Cystic Fibrosis * microbiology MeSH
- Child MeSH
- Adult MeSH
- Respiratory Tract Infections * microbiology MeSH
- Culture Techniques * methods MeSH
- Humans MeSH
- Specimen Handling MeSH
- Pseudomonas aeruginosa isolation & purification MeSH
- Sputum microbiology MeSH
- Stenotrophomonas maltophilia isolation & purification MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Publication type
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND AND AIMS: S. anginosus, constellatus and intermedius, also known as the Streptococcus milleri group (SMG) are three streptococcal species more frequently detected in cases of invasive disease, abscesses and empyema in particular. Recent research suggests they play a role in exacerbations of cystic fibrosis (CF). Owing to poor recovery on standard culture media and difficult differentiation from non-pathogenic streptococci, SMG may be underdiagnosed in routine settings. We aimed to establish the incidence of SMG in chronic obstructive pulmonary disease (COPD) patients compared to CF patients and to examine possible links of SMG to exacerbations that plays a key role in progression of COPD. METHODS: Altogether, 90 respiratory tract samples of patients suffering from CF or COPD were examined during the period from July 2012 to December 2013. Semi-selective McKay agar was used for primary cultivation of SMG and MALDI TOF MS was used for species identification that was confirmed by biochemical profiling and specific PCR. RESULTS: We confirmed the presence of SMG in CF (17.6% incidence in adult patients) and newly established its presence in COPD (10.3% incidence). In COPD, SMG was detected in 4 cases of acute exacerbations, where no other bacterial pathogen was detected. In 3/4 cases, increased CRP level indicated bacterial infection as a cause of the exacerbation and in all 3 cases, patients recovered during antibiotic treatment. CONCLUSIONS: Our data indicate SMG may act as opportunist pathogens able to cause exacerbations in COPD.
- MeSH
- Acute Disease MeSH
- Pulmonary Disease, Chronic Obstructive MeSH
- Cystic Fibrosis microbiology MeSH
- Adult MeSH
- Respiratory Tract Infections microbiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Opportunistic Infections microbiology MeSH
- Aged MeSH
- Streptococcus milleri Group isolation & purification MeSH
- Sputum microbiology MeSH
- Streptococcal Infections microbiology MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- MeSH
- Cystic Fibrosis immunology MeSH
- Exophiala immunology MeSH
- Immunoglobulin G immunology MeSH
- Humans MeSH
- Phaeohyphomycosis immunology MeSH
- Antibodies, Anti-Idiotypic immunology MeSH
- Antibodies, Fungal immunology MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Letter MeSH
- Comment MeSH
- Research Support, Non-U.S. Gov't MeSH
