Enhancement of microbicidal efficacy of chemical disinfectants when combined with ultrasound technology

AIMS

This study investigated the antimicrobial efficacy of ultrasound technology (US) in combination with two different disinfectants (Disinfectant A and Disinfectant B), containing peracetic acid (PAA) and quaternary ammonium compounds (QACs), respectively, against two sporigenic pathogens, Aspergillus brasiliensis and Bacillus subtilis.

METHODS AND RESULTS

The microbicidal activity of the coupled treatment was compared with the use of the disinfectants alone, and the efficacy of the disinfection strategies was evaluated by the log reduction of the population of the microorganism inoculated onto stainless-steel surface. The combination treatment resulted in a log reduction of 5.40 and 3.88 (Disinfectant A + US) against A. brasiliensis and B. subtilis, at 850 and 500 ppm PAA, compared to 265 and 122 (Disinfectant A only). For Disinfectant B, in combination with US, showed a logarithmic reduction of 5.04 and 4.79 against A. brasiliensis and B. subtilis at 078% v v-1 and 392% v v-1 QACs, respectively, vs. 1.58 and 1.64 (Disinfectant B only). Moreover, no colonies or not statistically significant growth was observed within the US bath containing the disinfectant.

CONCLUSIONS

The antimicrobial efficacy of the two disinfectants was greatly enhanced when used in combination with US, and this also makes it possible to avoid the overuse of chemicals for disinfection.

Assembly and dynamics of the apple carposphere microbiome during fruit development and storage

Microbial communities associated with fruit can contribute to quality and pathogen resistance, but little is known about their assembly and dynamics during fruit development and storage. Three apple cultivars growing under the same environmental conditions were utilized to examine the apple carposphere microbiome composition and structure at different developmental stages and storage. There was a significant effect (Adonis, p ≤ 0.001) of fruit genotype and its developmental stages and storage times on the fruit surface microbial assemblage and a strong temporal microbial community succession was detected (Mantel test: R ≤ 0.5, p = 0.001) in both bacterial and fungal communities. A set of 15 bacterial and 35 fungal core successional taxa and members exhibiting differential abundances at different fruit stages were identified. For the first time, we show the existence of underlying universal dynamics in the assembly of fruit-associated microbiomes. We also provide evidence of strong microbial cross-domain associations and uncover potential microbe-microbe correlations in the apple carposphere. Together our findings shed light on how the fruit carposphere assemble and change over time, and provide new insights into fruit microbial ecology.

The predictive role of neutrophil-to-lymphocyte ratio in post-operative arrhythmias in pediatric patients after cardiopulmonary bypass surgery

Background

Postoperative arrhythmias (POA) are a common complication after cardiac surgical repairs for congenital heart disease (CHD), representing a substantial source of morbidity, mortality and prolonged total in-hospital stay, with an incidence of 7.5–48% in postoperative pediatric cardiac patients. The etiology is multifactorial, and it has been related to the direct surgical manipulation of the cardiac conduction system, to the local tissue inflammation in the myocardium adjacent to the conduction system and to the arrhythmogenic effects of cardiopulmonary bypass (CPB), inotropes and electrolyte disturbances. Recently, the prognostic role of neutrophil-to-lymphocyte ratio (NLR), a novel inflammation marker, has been evaluated in pediatric patients after CPB surgery.

Purpose

To evaluate the predictive role of NLR in POA in a population of pediatric CHD patients after CPB.

Methods

We retrospectively collected perioperative clinical and laboratory data of 146 patients (age 8.27±10.79 years; male gender: 60.8%) consecutively admitted to the cardiac surgery intensive care unit (ICU) of our institute after elective cardiac surgery with CPB in 2018. We grouped and analyzed our population over NLR tertiles evaluated at 24 hours from CPB and types of POA: supraventricular (SVT) and junctional (JET). The prognostic value of NLR and its association with POA was analyzed.

Results

Diagnoses of 146 patients included atrial septal defect (n=36), ventricular septal defect (n=20), pulmonary atresia/stenosis (n=10), tetralogy of Fallot (n=20), endocardial cushion defect (n=8), left ventricular outflow tract obstruction (n=14), anomalous origin of coronary artery (n=6), complex CHD (n=13), interrupted/hypoplastic aortic arch (n=12), anomalous pulmonary artery venous return (n=3). The mean CPB time was 121.6±84.6 minutes. The median ICU hospitalization was 48 hours [Q1, Q3: 24, 96]. Twelve patients experienced POA: 6 SVT and 6 JET. The frequency of POA incremented over NLR-tertiles (P-Trend 0.017), while SVT onset was associated with higher values of NLR and C-reactive protein (P=0.034 and P=0.011, respectively). Patients in the second and third tertiles of NLR had a prolonged hospitalization (Log-rank, P=0.029), especially when associated with POA (Log-rank, P=0.012). At the multivariable analysis, higher age and NLR values were independently associated with SVT [OR per year 1.22; 95% CI (1.02, 1.25), P=0.043 and OR per point 1.91; 95% CI (1.29, 2.82), P=0.012, respectively], but not with JET.

Conclusions

24-h post-CPB NLR can predict postoperative SVT in a population of pediatric CHD patients. Our data suggest that the NLR could be a useful, easy-to-obtain marker for postoperative outcome in pediatric patients who had undergone elective CPB.

Funding Acknowledgement

Type of funding sources: None.

Global analysis of the apple fruit microbiome: are all apples the same?

We present the first worldwide study on the apple (Malus × domestica) fruit microbiome that examines questions regarding the composition and the assembly of microbial communities on and in apple fruit. Results revealed that the composition and structure of the fungal and bacterial communities associated with apple fruit vary and are highly dependent on geographical location. The study also confirmed that the spatial variation in the fungal and bacterial composition of different fruit tissues exists at a global level. Fungal diversity varied significantly in fruit harvested in different geographical locations and suggests a potential link between location and the type and rate of postharvest diseases that develop in each country. The global core microbiome of apple fruit was represented by several beneficial microbial taxa and accounted for a large fraction of the fruit microbial community. The study provides foundational information about the apple fruit microbiome that can be utilized for the development of novel approaches for the management of fruit quality and safety, as well as for reducing losses due to the establishment and proliferation of postharvest pathogens. It also lays the groundwork for studying the complex microbial interactions that occur on apple fruit surfaces.

Yeasts and Bacterial Consortia from Kefir Grains Are Effective Biocontrol Agents of Postharvest Diseases of Fruits

Fungal pathogens in fruits and vegetables cause significant losses during handling, transportation, and storage. Biological control with microbial antagonists replacing the use of chemical fungicides is a major approach in postharvest disease control, and several products based on single antagonists have been developed but have limitations related to reduced and inconsistent performance under commercial conditions. One possible approach to enhance the biocontrol efficacy is to broaden the spectrum of the antagonistic action by employing compatible microbial consortia. Here, we explore commercial kefir grains, a natural probiotic microbial consortium, by culture-dependent and metagenomic approaches and observed a rich diversity of co-existing yeasts and bacterial population. We report effective inhibition of the postharvest pathogen Penicillium expansum on apple by using the grains in its fresh commercial and milk-activated forms. We observed few candidate bacteria and yeasts from the kefir grains that grew together over successive enrichment cycles, and these mixed fermentation cultures showed enhanced biocontrol activities as compared to the fresh commercial or milk-activated grains. We also report several individual species of bacteria and yeasts with biocontrol activities against Penicillium rots on apple and grapefruit. These species with antagonistic properties could be further exploited to develop a synthetic consortium to achieve enhanced antagonistic effects against a wide range of postharvest pathogens.

1163 Diagnostic performance of a new echocardiographic method for coronary arteries abnormalities assessment

Background

The echocardiographic assessment of coronary arteries abnormalities (CCA) has always been challenging. In this view, we aimed to assess the performance of a new echocardiographic-based diagnostic method for CAA in pediatric and young adults’ population.

Methods

over 5 years, we examined all the outpatients undergoing routine echocardiography in our department. Our method consisted of 4-focused specific view scan: parasternal short-axis, parasternal long-axis, both left and right outflow tract, and apical 5-chamber view. Coronary-CT confirmed the CAA diagnosis. Two independent physicians retrospective reviewed the echocardiographic images, in a double-blinded fashion (coronary-CT and diagnosis), for performance analysis.

Results

in 2014-18, 5,998 outpatients underwent echocardiography (median age 14 years [6, 21 - IQR]). A total of 27 CAA were diagnosed: overall prevalence 0.0045%, 0.022% of incidence. N = 17/27 were anomalous aortic origin of coronary arteries (AAOCA), N = 3/27 anomalous coronary arteries from the pulmonary artery (ACAPA), and 7/27 fistulas. After the implementation, we found a progressive increment of CAA diagnosis (P for Trend = 0.038), in particular of AAOCA: both left and right coronaries (P-trend = 0.021 and P = trend 0.010, respectively). Our method showed better sensitivity than traditional CAA echocardiographic evaluation: 85% vs 55%, P = 0.032 [AUC 0.77, 95% CI (0.68, 0.87) and AUC 0.92, 95% CI (0.85, 0.99), respectively], with a good interobserver agreement for the adjudicated double-blinded retrospective diagnosis (99.75%, K = 0.73, P < 0.001).

Conclusions

the application of a new echocardiographic-based method for CAA-detection led to a significantly increased rate of identified anomalies. This approach demonstrated better sensitivity than traditional echocardiographic assessment. Implementing this protocol in clinical practice may improve the CAA diagnosis, and probably reduce the occurrence of CAA-related sudden cardiac death.

Genetic Analysis of Phytophthora nicotianae Populations from Different Hosts Using Microsatellite Markers

In all, 231 isolates of Phytophthora nicotianae representing 14 populations from different host genera, including agricultural crops (Citrus, Nicotiana, and Lycopersicon), potted ornamental species in nurseries (Lavandula, Convolvulus, Myrtus, Correa, and Ruta), and other plant genera were characterized using simple-sequence repeat markers. In total, 99 multilocus genotypes (MLG) were identified, revealing a strong association between genetic grouping and host of recovery, with most MLG being associated with a single host genus. Significant differences in the structure of populations were revealed but clonality prevailed in all populations. Isolates from Citrus were found to be genetically related regardless of their geographic origin and were characterized by high genetic uniformity and high inbreeding coefficients. Higher variability was observed for other populations and a significant geographical structuring was determined for isolates from Nicotiana. Detected differences were related to the propagation and cultivation systems of different crops. Isolates obtained from Citrus spp. are more likely to be distributed worldwide with infected plant material whereas Nicotiana and Lycopersicon spp. are propagated by seed, which would not contribute to the spread of the pathogen and result in a greater chance for geographic isolation of lineages. With regard to ornamental species in nurseries, the high genetic variation is likely the result of the admixture of diverse pathogen genotypes through the trade of infected plant material from various geographic origins, the presence of several hosts in the same nursery, and genetic recombination through sexual reproduction of this heterothallic species.

Identification and validation of polymorphic microsatellite loci for the analysis of Phytophthora nicotianae populations

A large number of SSR loci were screened in the genomic assemblies of 14 different isolates of Phytophthora nicotianae and primers were developed for amplification of 17 markers distributed among different contigs. These loci were highly polymorphic and amplified from genetically distant isolates of the pathogen. Among these, nine were further validated using a multiplexed genotyping assay with differentially labeled primers (FAM or HEX) to allow for duplex PCR amplification. The use of reverse primers with a 5' PIG tail was important to increase the quality and reliability of the analyses. A total of 46 alleles were detected in 5 tester isolates of P. nicotianae representing the breadth of diversity in the species. Furthermore, a high incidence of heterozygosity was determined with two alleles detected in 67% of the primer/isolate combinations. Three different alleles where detected for a single locus/isolate combination, indicating variation in ploidy. These markers represent a valuable new tool for the characterization of populations of P. nicotianae.