Editorial: XXXIII SIMGBM Congress 2019 - Antimicrobials and Host-Pathogen Interactions

This Research Topic (RT) is intended to provide a collection of selected contributions in the broad area “Antimicrobials and Host-Pathogen Interactions” from the participants of “Microbiology 2019” congress organized by the Italian Society for General Microbiology and Microbial Biotechnology (SIMGBM, www.simgbm.it), which was held in Florence, Italy, on June 19–22, 2019. The congress was attended by 224 scientists from all over the world, and contributions relevant to this RT were collected from presentations in the following congress sessions: (i) Antibiotic resistome: where do antibiotic resistance genes come from? (ii) New antimicrobial strategies in the post-antibiotic era; (iii) Intercellular communication in host-pathogen interactions; (iv) New approaches to unravel fungal-host interactions; (v) Bacterial cell surface and signaling. The unifying concept of this RT originates from the increasing awareness that antimicrobial resistance (AMR) is a complex problem which should be addressed by a multifocal approach. Fundamental microbiological investigations in this direction involve understanding of the flow of AMR genes from the environment to human and animal pathogens, the development of new drugs to tackle AMR, and the discovery of new druggable targets to impairmicrobial growth and/or pathogenicity

An Integrative, Multiparametric Approach for the Comprehensive Assessment of Microbial Quality and Pollution in Aquaculture Systems

As the aquaculture sector significantly expanded worldwide in the past decades, the concept of sustainable aquaculture has developed with the challenge of not only maximizing benefits but also minimizing the negative impacts on the environment assuring, at the same time, food security. In this framework, monitoring and improving the microbiological water quality and animal health are a central topic. In the present study, we evaluated the seawater microbiological quality in a mariculture system located in a Mediterranean coastal area (Northern Ionian Sea, Italy). We furnished, for the first time, a microbial inventory based on conventional culture-based methods, integrated with the 16S rRNA gene metabarcoding approach for vibrios identification and diversity analyses, and further implemented with microbial metabolic profiling data obtained from the Biolog EcoPlate system. Microbiological pollution indicators, vibrios diversity, and microbial metabolism were determined in two different times of the year (July and December). All microbial parameters measured in July were markedly increased compared to those measured in December. The presence of potentially pathogenic vibrios is discussed concerning the risk of fish disease and human infections. Thus, the microbial inventory here proposed might represent a new multiparametric approach for the suitable surveillance of the microbial quality in a mariculture system. Consequently, it could be useful for ensuring the safety of both the reared species and the consumers in the light of sustainable, eco-friendly aquaculture management

Application of XeCl308nm excimer laser radiation to mutate industrial microorganisms

EnIn this study, we have investigated the effects of an XeCl308 nm excimer laser radiation on bacterial mutagenesis. Our experiments have revealed that the mutagenesis inducted by the XeCl308 nm excimer laser radiation is independent from RecA protein, the regulator of the SOS response, unlike UV254 nm radiation that is not mutagenic for Escherichia coli mutants lacking the RecA protein. This found suggests that the UV308 nm laser radiation might be mutagenic also in microorganisms naturally lacking the SOS response. To test this hypothesis, we applied our innovative mutagenesis approach on Nonomuraea ATCC 39727, an industrial strain producing an antibiotic, which is relatively refractory to UV254 nm radiation-induced mutagenesis. Our results demonstrated the efficiency of XeCl308 nm excimer laser radiation to induce mutagenesis in Nonomuraea ATCC 39727

Potential human and plant pathogenic species in airborne pm10 samples and relationships with chemical components and meteorological parameters

A preliminary local database of potential (opportunistic) airborne human and plant pathogenic and non-pathogenic species detected in PM10 samples collected in winter and spring is provided, in addition to their seasonal dependence and relationships with meteorological parameters and PM10 chemical species. The PM10 samples, collected at a Central Mediterranean coastal site, were analyzed by the 16S rRNA gene metabarcoding approach, and Spearman correlation coefficients and redundancy discriminant analysis tri-plots were used to investigate the main relationships. The screening of 1187 detected species allowed for the detection of 76 and 27 potential (opportunistic) human and plant pathogens, respectively. The bacterial structure of both pathogenic and non-pathogenic species varied from winter to spring and, consequently, the inter-species relationships among potential human pathogens, plant pathogens, and non-pathogenic species varied from winter to spring. Few non-pathogenic species and even fewer potential human pathogens were significantly correlated with meteorological parameters, according to the Spearman correlation coefficients. Conversely, several potential plant pathogens were strongly and positively correlated with temperature and wind speed and direction both in winter and in spring. The number of strong relationships between presumptive (human and plant) pathogens and non-pathogens, and meteorological parameters slightly increased from winter to spring. The sample chemical composition also varied from winter to spring. Some potential human and plant pathogens were correlated with chemicals mainly associated with marine aerosol and/or with soil dust, likely because terrestrial and aquatic environments were the main habitats of the detected bacterial species. The carrier role on the species seasonal variability was also investigated

DNA damage by a single intense shot of soft X-rays emitted by a laser-produced plasma

EnA suitable plane transmission line was developed and its behaviour analysed at 900 MHz radiofrequency fields to study the DNA mutability and repair of microorganisms. In this work, utilizing such a device, we investigated the behaviour of the DNA mutability and repair of Escherichia coli strains. The transmission line was very simple and versatile in changing its characteristic resistance and field intensity by varying its sizes. In absence of cell samples inside the transmission line, the relative modulation of the electric and/or magnetic field was ±31% with respect to the mean values, allowing the processing of more samples at different exposure fields in a single run. Slight decrease in spontaneous mutability to rifampicin-resistance of the E. Coli JC411 strain, was demonstrated in mismatch-repair proficient samples exposed to the radio-frequency fields during their growth on solid medium

Characterization of the Airborne Microbiome in Different Indoor and Outdoor Locations of a University Building Using an Innovative Compositional Data Analysis Approach

In this work, we investigated the structure of the airborne bacterial community obtained by 16S rRNA gene sequencing performed on aerosol samples from different indoor and outdoor locations. The 48-h aerosol samples were collected in two laboratories, in the corridors, and on the roof of the Mathematics and Physics Department of the University of Salento (Italy). The investigation was carried out through the application of an innovative compositional data analysis approach, mainly based on a centered log-ratio transformation as a standardization procedure, the Aitchison distance for data ordination, and the principal component analysis via singular value decomposition for data clustering. This methodology allowed us to explore the main relationships among samples, identifying different results between indoor and outdoor samples both at the genus level and at the species level. Bacillus and Pseudomonas represented the most abundant genera identified in the analyzed samples. Out of the 21 identified bacterial species with the highest abundances in the collected aerosol samples, Acinetobacter lwoffii, Propionibacterium acnes, Diplorickettsia massiliensis, and Corynebacterium tuberculostearicum were the only four commonly classified as human opportunistic pathogens. Among the genera mostly associated with indoor environments, Hymenobacter and Arthrobacter could be noted as including many species that are unique in being radiation resistant

Nutritional composition of a selected white food-grade waxy sorghum variety grown in Mediterranean environment

A white food-grade waxy sorghum Tw variety, grown in two Mediterranean sites (named Tw1M and Tw1S) was evaluated for nutrient composition and fatty acid- and mineral concentrations in order to determine the suitability of producing waxy sorghum for human uses in southern Italy. The nutritional values of the grains of the Tw inbred line grown in the two trial fields were substantially the same, except for slight differences in ash level and accordingly slight variation in mineral composition. In samples from both locations, a higher percentage of K was observed among the nutritionally essential macro-elements, and higher percentages of Zn, Fe, Mn, Cu, Al among the nutritionally essential micro-element along with a strong difference in Cd content was among trace elements. Across both sites linoleic, oleic and palmitic were the most abundant fatty acids, while very slight variations in the content of minerals were found among the two samples examined. These results demonstrate the importance of developing agronomically productive waxy sorghum varieties suitable for growth in non-traditional sorghum producing regions both as a food and feed crop (i.e. with good nutritional quality) and for utilization in new products at the industrial level

Interplay between non-coding rna transcription, stringent/relaxed phenotype and antibiotic production in streptomyces ambofaciens

While in recent years the key role of non-coding RNAs (ncRNAs) in the regulation of gene expression has become increasingly evident, their interaction with the global regulatory circuits is still obscure. Here we analyzed the structure and organization of the transcriptome of Streptomyces ambofaciens, the producer of spiramycin. We identified ncRNAs including 45 small-RNAs (sRNAs) and 119 antisense-RNAs (asRNAs I) that appear transcribed from dedicated promoters. Some sRNAs and asRNAs are unprecedented in Streptomyces and were predicted to target mRNAs encoding proteins involved in transcription, translation, ribosomal structure and biogenesis, and regulation of morphological and biochemical differentiation. We then compared ncRNA expression in three strains: (i) the wild-type strain; (ii) an isogenic pirA-defective mutant with central carbon metabolism imbalance, “relaxed” phenotype, and repression of antibiotic production; and (iii) a pirA-derivative strain harboring a “stringent” RNA polymerase that suppresses pirA-associated phenotypes. Data indicated that the expression of most ncRNAs was correlated to the stringent/relaxed phenotype suggesting novel effector mechanisms of the stringent response

Sorgenti laser per biomateriali

In questo lavoro vengono messe a confronto due diverse tecniche per migliorare le proprietà delle superfici di materiali biomedici; l‟irraggiamento laser e l‟impiantazione ionica. L‟irraggiamento laser è eseguito mediante una sorgente ad eccimeri KrF e l‟impiantazione ionica mediante l‟acceleratore Platone che utilizza la tecnica LIS (Laser Ion Source). Mi-sure di angolo di contatto e rugosità sono state eseguite sui campioni prima e dopo ogni trattamento in modo da avere informazioni sulle modifiche. L‟impiantazione ionica è stata eseguita anche su target di acciaio AISI 420, lega utilizzata per realizzare strumenti medicali. Si è visto che l‟utilizzo di fasci di ioni di Ag aumenta l‟antibattericità degli strumenti

Oral complications of Type 1 diabetes mellitus in a non-smoking population

Type 1 diabetes mellitus (T1DM) is a complex metabolic condition that results in hyperglycemia due to insulin deficiency (Daneman, 2006). Diabetes has a range of effects on almost every system in the body including the kidneys, the eyes, the cardiovascular system, the genito-urinary system, the gastro-intestinal system and the nervous system (Daneman, 2006). The effects of this ondition are widespread and have a significant impact both on life expectancy and the quality of life of individuals suffering from diabetes (Scottish Diabetes Survey Monitoring Group, 2011). The impact of diabetes on oral health has been investigated over many decades, however, the conclusions have been varied and study design has not always been adequate (Mealey et al., 2006; Khader et al., 2006; Chávarray et al., 2009). Research presented in this thesis is largely the result of a cross-sectional clinical study examining the oral cavities of non-smoking T1DM patients, funded by the Chief Scientist Office of the Scottish Government. The clinical part of the study took place between January 2006 and May 2009 in Glasgow Dental Hospital. Chapter one provides an introduction and narrative review on the subject of T1DM, periodontal disease, and the various other reported oral manifestations of diabetes mellitus. The methods for measuring general and oral health related quality of life outcomes are also discussed. Chapter one reveals some of the inadequacies of studies nvestigating the link between T1DM and oral disease to date and ontextualises the studies presented in this thesis. Chapter two presents the main periodontal findings of a large cross-sectional study. 112 non-diabetic subjects and 203 subjects with type 1 diabetes were examined. 203 diabetic patients were divided into well controlled and poorly controlled groups based on their average blood sugar levels over the previous two years. 169 were poorly controlled. (PCD). Those with T1DM, (especially those with poor glycaemic control) had a greater extent and severity of periodontitis than those without diabetes. There was also some evidence that never smoking T1DM patients were more likely to have periodontal disease than non-diabetic subjects. The odds ratio (OR) was 1.43 [0.74 to 2.75] (p = 0.29) for all T1DM patients and 1.58 [0.75 to 3.33] (p = 0.23) for PCD. This difference remained even after the multivariable analysis took into account age, gender and lifestyle including: body mass index of the subject; whether they had smoked in the past; whether they attended a dentist; their level of education and how deprived the area they lived in was. Chapter three presents an analysis of the impact of age, HbA1c, and duration on the expression of periodontal disease in T1DM subjects. Cross-tabulations and multivariable logistic regression analysis was performed on the periodontal data from T1DM subjects and non-diabetic subjects in order to determine the relationship between age, HbA1c and duration, and periodontitis. Diabetic subjects developed periodontitis at a younger age than non-diabetes subjects. This will represent a significant impact on life time dental service provision for subjects affected at a young age. The relationship between HbA1c and severe periodontitis is not a simple one. It is possible that unknown factors confound the relationship between glycaemic control and periodontitis. There was no relationship between duration of diabetes and periodontitis when age was controlled for. Chapter four presents the results of a small study investigating biomarkers of bone turnover in patients with and without T1DM and in patients with and without periodontitis. Patients with T1DM had higher levels of osteoprotegerin an osteoprotective molecule that normally leads to a reduced propensity for bone loss. T1DM patients were also shown to have reduced levels of biomarkers of bone formation (osteocalcin). It is possible that a reduced capacity for bone repair and regeneration may account for the increase levels of periodontitis seen in T1DM. Further prospective studies would be required to confirm this hypothesis. Chapter five investigated the level of caries and oral mucosal abnormalities in T1DM. There was little difference in caries indicators or in oral mucosal lesions between the groups. There was no difference in the bacterial microflora and in the level of resistance to antibiotics found in this cohort. T1DM patients, however, did have an increase in the symptoms of dry mouth, an increased density of candida colonisation and reduced salivary flow rates.Chapter six reports the data derived from the oral health questionnaire, including the Oral Health Impact Profile -14 (OHIP-14) and the Audit of Diabetes Dependent Quality of Life (ADDQOL©). Patients with T1DM, despite having increased levels of periodontal disease, reduced salivary flow rates and increased symptoms of xerostomia did not have higher OHIP scores by any measure. The reasons for this apparently negligible impact of oral disease or oral health related quality of life are discussed. The OHIP-14 was shown to have construct validity in this population although the correlations were relatively weak and the differences were small. It is possible that patients with T1DM do not consider the impact of their oral health to be a significant problem in light of their other on-going medical issues. This finding requires further in-depth investigation of the psychology behind this apparent reduced impact. This is the first study of its kind to examine the oral and dental health of non-smoking type 1 diabetic patients. The conclusions from the clinical data support the view that patients with T1DM should be targeted with oral and dental health advice. Encouragingly the prevalence of periodontitis was lower in well controlled diabetic subjects suggesting that the effect of T1DM on the oral cavity can be ameliorated by good glycaemic control even though logistic regression analysis did not show a linear relationship. It is important that health rofessionals work together in order to prevent and manage the oral complications of T1DM in the same way that there are preventive and screening programmes for other diabetic complications. The pathogenesis behind the increased prevalence and severity of periodontal disease in T1DM requires further study.EThOS - Electronic Theses Online ServiceGBUnited Kingdo