Abstract
Extra-pulmonary mycobacterial infections are characterized by a paucibacillary nature and extra-pulmonary samples consist of different matrices; the processing of these samples requires a ...high level of manual skills and non-standardized procedures. The aim of this study was to compare the performance of MYCO-TB with MycoPrep on extra-pulmonary samples in terms of Mycobacteria detection, culture contamination and suitability for molecular assay. This prospective study was conducted on 201 extra-pulmonary samples from suspected cases of mycobacterial infection. Specimens were divided into two equal aliquots; one was decontaminated with MYCO-TB the other with MycoPrep. The contamination rate of liquid cultures was significantly different: 2.5% (5/201) for MYCO-TB and 7.5% (15/201) for MycoPrep (
p
= 0.036). At least 1
Mycobacterium tuberculosis
complex (MTBc) positive culture was detected in 6 specimens treated with MYCO-TB and 8with MycoPrep, without significant differences in times to positivity (TTP) in liquid culture. No Xpert MTB/RIF Ultra invalid results were obtained with samples decontaminated with MYCO-TB. The MYCO-TB kit had greater activity than MycoPrep in the digestion and decontamination of extra-pulmonary specimens for the detection of Mycobacteria, supporting the use of MYCO-TB in this type of sample. Ready-to use reagents, rapid protocol and single-sample formulation of MYCO-TB reduced the level of manual skills required as well as the risk of sample contamination.
•Caloric cooling could represent the answer for next-generation cooling devices.•Two all-polymer elastocaloric heat pumps using natural rubber tubes are presented.•The performances are as high as ...those for other caloric material devices.•A temperature span > 8 K, a COP of 6, and a cooling power of 1.5 W were achieved.•The devices can be potentially scaled-up, paving the way to larger scale attempts.
Alternative methods of refrigeration are critical for performance optimization and environ- mental sustainability. Prototype systems using caloric materials have shown the advantages of a high coefficient of performance (COP) and low global warming potential. Elastocaloric elastomers can meet ongoing needs, but their implementation in functional heat pumps or coolers remains challenging due to their requirement for a large deformation and low thermal conductivity. Moreover, a scalable design is required to achieve high cooling power. As a leap forward for the use of polymers in larger scale caloric devices, we developed experimental elastocaloric polymer coolers with two different geometries using natural rubber tubes. We confirmed that a suitable geometry partially compensated for the low thermal conductivity and led to performances comparable to those of other caloric devices. Several operating conditions were tested to determine the optimal temperature span, cooling power, and COP for both device geometries. Under a specific operating condition, one of the prototypes exhibited a maximum temperature span > 8 K, a maximum COP of 6, and an output cooling power of 1.5 W; this power outperforms other prototypes based on polymers or ceramics. The parallelization of rubber tubes will facilitate realistic elastocaloric polymer coolers on a larger scale.
Extrapulmonary tuberculosis (EPTB) accounts for more than 20% of tuberculosis (TB) cases. Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, CA, USA) is a fully automated amplification system, for which ...excellent results in the diagnosis of pulmonary TB in highly endemic countries have been recently reported. We aimed to assess the performance of the Xpert system in diagnosing EPTB in a low incidence setting. We investigated with Xpert a large number of consecutive extrapulmonary clinical specimens (1,476, corresponding to 1,068 patients) including both paediatric (494) and adult samples. We found, in comparison with a reference standard consisting of combination of culture and clinical diagnosis of TB, an overall sensitivity and specificity of 81.3% and 99.8% for Xpert, while the sensitivity of microscopy was 48%. For biopsies, urines, pus and cerebrospinal fluids the sensitivity exceeded 85%, while it was slightly under 80% for gastric aspirates. It was, in contrast, lower than 50% for cavitary fluids. High sensitivity and specificity (86.9% and 99.7%, respectively) were also obtained for paediatric specimens. Although the role of culture remains central in the microbiological diagnosis of EPTB, the sensitivity of Xpert in rapidly diagnosing the disease makes it a much better choice compared to smear microscopy. The ability to rule out the disease still remains suboptimal.
Mycobacterium saskatchewanense is a species of pigmented slow-growing Non-Tuberculous Mycobacteria (NTM), positive for Mycobacterium avium complex (MAC) by AccuProbe system. MAC organisms have ...frequently been isolated from different medical devices. This is the first study reporting isolation of M. saskatchewanense from medical devices and highlights the importance of correctly identifying the NTMs that often colonize sanitary water. GenoType Mycobacterium CM CE-IVD kit (CM) was used as the first step of NTM strain identification, and all positive cultures were found to be components of MAC. Then, GenoType NTM-DR CE-IVD kit (NTM-DR) was used to differentiate the different species. Sub-culture on solid media were used for: (i) phenotypical confirmation by colony morphology and Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry; (ii) molecular confirmation by Next Generation Sequencing. All positive cultures were identified as M. intracellulare by CM and NTM-DR assays, whereas colony morphology showed bright yellow scotochromogenic growth. MALDI-TOF analyses identified the strains as M. saskatchewanense with a high score, and identification was confirmed by NGS analysis based on the hsp-65 region. This paper suggests that it is important to actively monitor NTM contamination in medical devices that use sanitary water, to prevent the possibility of patients becoming infected.
Diagnosis of pulmonary (PTB) and extra-pulmonary tuberculosis (EPTB) in smear-negative patients can be difficult. We assessed retrospectively the performance of Xpert MTB/RIF system (Xpert, Cepheid) ...in diagnosing smear-negative tuberculosis (TB), which represents the most common form of TB in a low incidence setting.
Performance of Xpert was compared to acid-fast microscopic examination using Ziehl-Neelsen (ZN) stain in patients with culture-confirmed TB.
386 Mycobacterium tuberculosis (MTB) culture-positive samples were detected out of 5170 specimens tested with smear microscopy, Xpert and culture: 323 were both culture- and Xpert-positive, and 63 culture-positive only. Of these, 234 (60.6%) were smear-negative. In addition Xpert detected 40 probable TB cases, based on clinical findings, which were culture-negative. Compared to culture, Xpert showed an overall sensitivity of 83.7% and a specificity of 99.1%; sensitivity was higher for respiratory samples (86.5%) than for non-respiratory samples (76.8%). Xpert sensitivity for smear-negative culture-confirmed TB was 73.1% and was not influenced by TB localization. As sensitivity of microscopy alone was poor (39.4%), Xpert improved both diagnosis of pulmonary TB (Δ = 36.5%) and extra-pulmonary TB (Δ = 63.4%).
Xpert MTB/RIF is a sensitive method for rapid diagnosis of TB compared to the conventional ZN staining. Xpert can serve as a sensitive and time-saving diagnostic method for microbiological diagnosis of smear-negative TB in countries with a low TB prevalence.
Clinical interpretation of trace results by Xpert MTB/RIF Ultra assay (Ultra) used as an initial diagnostic test for tuberculosis (TB) may be challenging. The aim of the study was to evaluate the ...frequency and epidemiology of trace readouts in routine clinical practice in a low TB prevalence setting and to propose guidance on how to manage patients with trace calls considering the data available (clinical, radiological, bacteriological etc.). A retrospective, observational, monocentric study was conducted at IRCCS Azienda Ospedaliero-Universitaria of Bologna, Italy between November 2017-December 2020. Presumptive TB patients with at least one Ultra trace result during diagnostic workup before treatment were included in the study. Patients with ongoing anti-TB treatment at the time of the trace call result or with no clinical data available were excluded from the study. Fifty-nine presumptive TB patients with Ultra trace readouts were included in the study (mean age 37.0 years, 61% males). Four patients had a history of TB in the last 2 years. Twenty-five (42.4%) of the 59 samples with trace results were respiratory material. 57/59 (96.6%) patients started anti-TB treatment soon after obtaining trace results, based on clinical, radiological or other information available, while for two patients with a recent history of TB the trace result did not lead to anti-TB treatment. Culture was positive for M. tuberculosis for 31/59 (52.5%) samples with trace calls: 13/25 (52.0%) were respiratory samples and 18/33 (54.5%) non-respiratory samples. The clinical and/or radiological findings of 47/57 (82.4%) patients given anti-TB therapy improved during treatment. In low TB incidence settings, Ultra trace calls in presumptive TB patients should be considered as true-positive and treatment should be started promptly, except in cases of recent history of TB, where careful evaluation of other diagnostic criteria is necessary before starting anti-TB treatment. A decisional algorithm for clinical management is proposed.
The new Xpert MTB/RIF Ultra assay (Ultra, Cepheid, Sunnyvale, USA) is a cartridge-based automated diagnostic test that can simultaneously identify Mycobacterium tuberculosis complex (MTB) and ...resistance to Rifampicin (RIF). With respect to the previous version Xpert MTB/RIF assay (Xpert), IS6110/IS1081 repetitive elements probes have been added allowing the detection of lower MTB load, defined by the new semi-quantitative category "trace" with indeterminate RIF resistance. The aim of this study was to evaluate performance of the new version Ultra on Xpert-negative, but TB culture-positive clinical samples.
The de-identified frozen samples (-20 °C) collected over a 4-year period (February 2014-October 2017), which had previously resulted smear-negative, Xpert-negative but MTB culture-positive, were analyzed with Ultra. The de-frosted samples were loaded into the cartridge using the same process as the previous version, according to manufacturer's instruction.
During the study period 382 MTB culture-positive samples were archived: 314 resulted Xpert-positive and 68 Xpert-negative. Thirty-one of the 68 Xpert-negative samples resulted positive with Ultra, with an overall improvement in MTB detection of 45.6%. Out of 36 Xpert-negative respiratory samples, 18 resulted Ultra-positive with the following semi-quantitative loads: "low"(n = 1), "very low"(n = 11), "trace"(n = 6), with an improvement in MTB detection of 50%. The best performance was achieved on bronchoalveolar lavage specimens (53.8%). Out of 32 Xpert-negative non-respiratory samples, 13 resulted Ultra-positive with the following semi-quantitative loads: "very low"(n = 7), "trace"(n = 6), with an improvement in MTB detection of 40.6%. The best performance was achieved on biopsies (55.6%) and lymph nodes (50%). The new category "trace" detected 12 out of the 31 Ultra-positive MTB samples; in the remaining 19 samples RIF susceptibility was determined with 100% concordance with the phenotypic susceptibility test. The mean time to positivity of samples found negative by Ultra was significantly longer in comparison to positive samples in liquid culture.
Our results are consistent with the few studies published so far and confirm the better performance of Ultra compared to the previous version in both respiratory and non-respiratory smear-negative samples, with an overall improvement of 45.6%.
Sensibilizzare i funzionari della PA sulla necessità di redigere atti amministrativi chiari e sintetici è ancora un tema attuale e urgente, nonostante le numerose iniziative intraprese in questa ...direzione negli ultimi anni. Nell’ambito di una collaborazione scientifica tra CNR IGSG e Città Metropolitana di Venezia, è stato sperimentato un nuovo modello didattico per la formazione linguistica dei funzionari. Tale metodo prevede l’integrazione del format erogativo-trasmissivo tradizionale con un format applicativo-laboratoriale, attraverso l’utilizzo di una piattaforma digitale per lo student engagement (Wooclap). Questo articolo dà conto dell’esperienza realizzata, analizzando vantaggi e limiti dell’utilizzo integrato delle tecnologie ICT per i laboratori sulla scrittura amministrativa, col fine di alimentare la condivisione di buone pratiche in questo ambito. Teaching practices on the drafting of acts Raising civil servants’ awareness of the importance of writing clear and concise administrative documents is still a topical and urgent issue, despite the many initiatives taken in recent years. As part of a scientific collaboration between CNR IGSG and the Metropolitan City of Venice, a new didactic model to train civil servants in administrative writing was tested. This method proposes that the traditional frontal teaching format be integrated with a laboratory format that employs the use of a digital platform designed to stimulate the students engagement (Wooclap). The aim of this article is to report on the experience gained, to analyse the advantages and limitations of the integrated use of ICT technologies for administrative writing workshops, and to promote the exchange of good practices in this field.
Releasing considerable numbers of radiation-sterilized males is a promising strategy to suppress mosquito vectors. However, releases may also include small percentages of biting females, which ...translate to non-negligible numbers when releases are large. Currently, the effects of irradiation on host-seeking and host-biting behaviors have not been exhaustively investigated. Information is also lacking regarding the effects of sterilizing treatment on the endosymbiotic bacterium Wolbachia, which is known to affect the vector competence of infected mosquitos.
To ascertain the effects of irradiation on females, the pupae of two Aedes albopictus strains, differing in their natural or artificial Wolbachia infection type, and Aedes aegypti-which is not infected by Wolbachia-were treated with various doses of X-rays and monitored for key fitness parameters and biting behavior over a period of 2 weeks. The effect of radiation on Wolbachia was investigated by quantitative polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) analysis.
Partial Aedes albopictus female sterility was achieved at 28 Gy, but the number of weekly bites more than doubled compared to that of the controls. Radiation doses of 35 and 45 Gy completely inhibited progeny production but did not significantly affect the survival or flight ability of Ae. albopictus females and caused a tripling of the number of bites per female per week (compared to untreated controls). These results were also confirmed in Ae. aegypti after treatment at 50 Gy. Wolbachia density decreased significantly in 45-Gy-irradiated females, with the greatest decreases in the early irradiation group (26 ± 2-h-old pupae). Wolbachia density also decreased as adults aged. This trend was confirmed in ovaries but not in extra-ovarian tissues. FISH analysis showed a strongly reduced Wolbachia-specific fluorescence in the ovaries of 13 ± 1-day-old females.
These results suggest that, under sterile insect technique (SIT) programs, the vector capacity of a target population could increase with the frequency of the irradiated females co-released with the sterile males due to an increased biting rate. In the context of successful suppression, the related safety issues are expected to be generally negligible, but they should be conservatively evaluated when large-scale programs relying on imperfect sexing and high overflooding release ratios are run for long periods in areas endemic for arboviral diseases. Also, the effects of irradiation on the vector competence deserve further investigation.
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