Towards an automatic system for monitoring of CN2 and wind speed profiles with GeMS

Wide Field Adaptive Optics (WFAO) systems represent the more sophisticated AO systems available today at large telescopes. A critical aspect for these WFAO systems in order to deliver an optimised performance is the knowledge of the vertical spatiotemporal distribution of the CN2 and the wind speed. Previous studies (Cortes et al., 2012) already proved the ability of GeMS (the Gemini Multi-Conjugated AO system) in retrieving CN2 and wind vertical stratification using the telemetry data. To assess the reliability of the GeMS wind speed estimates a preliminary study (Neichel et al., 2014) compared wind speed retrieved from GeMS with that obtained with the atmospherical model Meso-Nh on a small sample of nights providing promising results. The latter technique is very reliable for the wind speed vertical stratification. The model outputs gave, indeed, an excellent agreement with a large sample of radiosoundings (~ 50) both in statistical terms and on individual flights (Masciadri et al., 2013). Such a tool can therefore be used as a valuable reference in this exercise of cross calibrating GeMS on-sky wind estimates with model predictions. In this contribution we achieved a two-fold results: (1) we extended analysis on a much richer statistical sample (~ 43 nights), we confirmed the preliminary results and we found an even better correlation between GeMS observations and the atmospherical model with basically no cases of not-negligible uncertainties; (2) we evaluate the possibility to use, as an input for GeMS, the Meso-Nh estimates of the wind speed stratification in an operational configuration. Under this configuration these estimates can be provided many hours in advanced with respect to the observations and with a very high temporal frequency (order of 2 minutes or less).Comment: 12 pages, 7 figures, Proc. SPIE 9909 "Adaptive Optics Systems V", 99093B, 201

Towards an automatic wind speed and direction profiler for Wide Field AO systems

Wide Field Adaptive Optics (WFAO) systems are among the most sophisticated AO systems available today on large telescopes. The knowledge of the vertical spatio-temporal distribution of the wind speed (WS) and direction (WD) are fundamental to optimize the performance of such systems. Previous studies already proved that the Gemini Multi-Conjugated AO system (GeMS) is able to retrieve measurements of the WS and WD stratification using the SLODAR technique and to store measurements in the telemetry data. In order to assess the reliability of these estimates and of the SLODAR technique applied to such a kind of complex AO systems, in this study we compared WS and WD retrieved from GeMS with those obtained with the atmospherical model Meso-Nh on a rich statistical sample of nights. It has been previously proved that, the latter technique, provided an excellent agreement with a large sample of radiosoundings both, in statistical terms and on individual flights. It can be considered, therefore, as an independent reference. The excellent agreement between GeMS measurements and the model that we find in this study, proves the robustness of the SLODAR approach. To by-pass the complex procedures necessary to achieve automatic measurements of the wind with GeMS, we propose a simple automatic method to monitor nightly WS and WD using the Meso-Nh model estimates. Such a method can be applied to whatever present or new generation facilities supported by WFAO systems. The interest of this study is, therefore, well beyond the optimization of GeMS performance.Comment: 9 figures, 2 tables, MNRAS accepte

Low Level of Colistin Resistance and mcr Genes Presence in Salmonella spp.: Evaluation of Isolates Collected between 2000 and 2020 from Animals and Environment

Salmonellosis is one of the most important zoonoses in Europe and the world. Human infection may evolve in severe clinical diseases, with the need for hospitalization and antimicrobial treatment. Colistin is now considered an important antimicrobial to treat infections from multidrugresistant Gram-negative bacteria, but the spreading of mobile colistin-resistance (mcr) genes has limited this option. We aimed to evaluate colistin minimum inhibitory concentration and the presence of mcr (mcr-1 to mcr-9) genes in 236 Salmonella isolates previously collected from different animals and the environment between 2000 and 2020. Overall, 17.79% of isolates were resistant to colistin; no differences were observed in relation to years of isolation (2000–2005, 2009–2014, and 2015–2020), Salmonella enterica subspecies (enterica, salamae, diarizonae, and houtenae), origin of samples (domestic animals, wildlife, and environment), or animal category (birds, mammals, and reptiles); only recently isolated strains from houseflies showed the most resistance. Few isolates (5.93%) scored positive for mcr genes, in particular for mcr-1, mcr-2, mcr-4, mcr-6, and mcr-8; furthermore, only 2.54% of isolates were mcr-positive and colistin-resistant. Detected resistance to colistin was equally distributed among all examined Salmonella isolates and not always related to the presence of mcr genes

Effect of a Lactobacillus sakei and Staphylococcus xylosus protective culture on Listeria monocytogenes growth and quality traits of Italian fresh sausage (salsiccia) stored at abusive temperature

Fresh sausages are not always thoroughly cooked before consumption and can support the growth of pathogenic microorganisms, especially when stored at incorrect temperatures. The aim of this study was to verify the growth of Listeria monocytogenes in Italian salsiccia stored at 2 °C, 7 °C and 12 °C for 9 days (t9) with (PC+) and without (PC–) a commercial protective culture (Lactobacillus sakei and Staphylococcus xylosus). L. monocytogenes PC + counts were statistically different from PC–, after 7 days (t7) at 7 °C and at 12 °C. At 2 °C, they increased in PC + by 0.03 and 0.36 log CFU/g vs. 0.25 and 0.91 in PC–, at t7 and t9. Moreover, quality characteristics (total aerobic counts, colour parameters, TBARS values, pH, sensory attributes) were assessed in fresh sausages stored at 7 °C. Significant differences were obtained in PC + samples at t7 for Pseudomonadaceae and Enterobacteriaceae (about 2 log CFU/g). Yeasts and moulds and Brochothrix thermosphacta were also significantly lower in PC + samples. PC + samples were more acidic than PC–, with statistically different colour parameters values particularly at the external surface; raw sausages resulted sensorially discernible at t7, whereas PC + and PC– cooked samples did not show any significant sensory difference. The studied protective culture proved to be a useful tool to increase safety and microbiological quality of salsiccia at abusive storage temperature, effectively limiting the growth of L. monocytogenes and Gram negative spoilage microorganisms, with some sensory drawbacks, especially at the end of the shelf life.HIGHLIGHTS The tested culture improves the microbial safety of salsiccia. It reduces the growth of spoilage microorganisms, especially Pseudomonadaceae and Enterobacteriaceae. It mainly influences colour and acidity evolution of the raw product with no sensory drawbacks in the cooked product

Genital brucella suis biovar 2 infection of wild boar (Sus scrofa) hunted in tuscany (Italy)

Brucellosis is a zoonosis caused by different Brucella species. Wild boar (Sus scrofa) could be infected by some species and represents an important reservoir, especially for B. suis biovar 2. This study aimed to investigate the prevalence of Brucella spp. by serological and molecular assays in wild boar hunted in Tuscany (Italy) during two hunting seasons. From 287 animals, sera, lymph nodes, livers, spleens, and reproductive system organs were collected. Within sera, 16 (5.74%) were positive to both rose bengal test (RBT) and complement fixation test (CFT), with titres ranging from 1:4 to 1:16 (corresponding to 20 and 80 ICFTU/mL, respectively). Brucella spp. DNA was detected in four lymph nodes (1.40%), five epididymides (1.74%), and one fetus pool (2.22%). All positive PCR samples belonged to Brucella suis biovar 2. The results of this investigation confirmed that wild boar represents a host for B. suis biovar. 2 and plays an important role in the epidemiology of brucellosis in central Italy. Additionally, epididymis localization confirms the possible venereal transmission

Listeria monocytogenes contamination of Tenebrio molitor larvae rearing substrate: Preliminary evaluations

Today, edible insects represent a hot topic as an emerging and eco-friendly source of protein. The mealworm (Tenebrio molitor L.) is among the most employed insects for human consumption and feed purposes. So far Listeria monocytogenes, have never been detected either in products sold on the market or during the rearing process. In this study, the substrate employed for mealworm rearing was deliberately contaminated with L. monocytogenes and the bacterium was enumerated during the rearing period and after technological treatments of the larvae. L. monocytogenes persisted during the rearing period. Washing the larvae did not produce any significant effect, while fasting the larvae for 24 or 48 h reduced the L. monocytogenes load (P < 0.001). Oven cooking eliminated L. monocytogenes cells from the product, reducing the risk associated to this foodborne pathogen to zero

Coagulase negative staphylococci from ovine bulk-tank milk: Effects of the exposure to sub-inhibitory concentrations of disinfectants for teat-dipping

Teat-dipping is one of the most effective methods to prevent mammary infections in ruminants, including sub-clinical mastitis caused by coagulase-negative staphylococci (CoNS). Improper disinfectant application could expose microorganisms to sub-inhibitory concentrations leading to phenotypic variations. In this study, 12 chlorhexidine-digluconate (CHDG)-tolerant (of which 4 qac positive) and 12 benzalkonium chloride (BC)-tolerant (of which 7 qac-positive) CoNS isolates from ovine milk were exposed to sub-inhibitory concentrations of CHDG and BC, respectively. Changes in disinfectant susceptibility against BC and CHDG, antibiotic resistance against 12 antibiotics and biofilm production were then assessed for both groups. After CHDG stress, 67 % and 83 % of the CHDG-stressed isolates doubled their MICs for BC and CHDG, respectively and 2 qac-negative isolates showed a four-fold increase of their MBCs for CHDG. After BC stress, MICs for BC and CHDG doubled in 58 % and 83 % of the BC-stressed isolates, respectively, while one qac-positive isolate increased four-fold the MIC for BC. Cross-resistance to antibiotics was assessed by disc diffusion method. Some qac-positive isolates varied their resistance profile, while a blaZ-positive isolate showed a resistant phenotype against ampicillin only after the exposure to the disinfectant. As for qac-positive isolates, one CHDG-stressed and 2 BC-stressed increased their resistance to kanamycin and cefoxitin, respectively. The Congo Red Agar test was carried out to assess the in vitro slime production: all isolates were negative after stress. In conclusion, sub-inhibitory exposure to disinfectants may affect disinfectant and antibiotic susceptibility, the latter in particular for qac-positive isolates and those hosting unexpressed antibiotic resistance genes

Antimicrobial activity of fifteen Italian honeys against Paenibacillus larvae ATCC 9545

Currently, American Foulbrood (AFB) represents one of the most important problems for beekeepers, due to economic losses and to the absence of an effective therapeutic treatment. The aim of this work was to characterize fifteen Italian honeys in order to assess their inhibitory activity against Paenibacillus larvae ATCC 9545. Each honey was analyzed for the activity of the following enzymes: glucose oxidase and catalase. Moreover, melissopalynological analysis and other biochemical parameters, namely gluconic acid, total phenolic and total flavonoid contents were determined. For each honey, the Minimum Inhibitory Concentration (M.I.C.) and the Minimum Bactericidal Concentration (M.B.C.) against P. larvae were determined. All tested honey samples had an inhibitory activity on P. larvae. In particular, the lowest M.I.C. and M.B.C. values (53.8 mg/mL and 107.5 mg/mL, respectively) were recorded for an Arbutus honey sample. Arbutus honeys also had the highest gluconic acid and total phenolic contents (12.6 ± 1.7 g/kg and 243.2 ± 25.1 mg/kg, respectively) and the highest glucose oxidase activity (13.0 ± 1.9 nM H2O2/min). Dark honeys, including Arbutus, seem to have a higher gluconic acid content and a higher antimicrobial activity. Thus, honey characterization, including colour and physico-chemical characteristics (e.g. gluconic acid concentration, total phenolic and total flavonoid contents, glucose oxidase activity), could be crucial for the assessment of its employment against P. larvae

Experimental infection with Yersinia pseudotuberculosis in European brown hare (Lepus europaeus, Pallas)

Objective To investigate clinicopathological, bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis (Y. pseudotuberculosis) in hares to verify the efficacy of serology for the in vivo diagnosis. Moreover, the pathogenicity of two Y. pseudotuberculosis strains was investigated in order to detect potential differences. Methods Twelve European brown hares (Lepus europaeus, Pallas) were experimentally infected per os and via conjunctival mucosae with Y. pseudotuberculosis: six subjects were infected with a strain isolated from a naturally infected hare (YpH) and six subjects with a strain isolated from a naturally infected rabbit (YpR). Two hares were used as negative controls. All animals were subjected to clinical, bacteriological and serological examinations during 9 weeks following the infection and, at the end of the control period, subjects still alive were euthanized and submitted to a complete post mortem examination. Results All faecal samples collected during the control period were positive for bacteriological examinations and to a PCR for the inv gene of Y. pseudotuberculosis, while only one YpH-infected hare showed a positive haemocultures. From the 2nd to the 9th week post infection (pi), serological analysis revealed specific antibodies with titers ranging from 1:10 to 1:160 in all YpH-infected and two YpR-infected subjects. All the YpH-infected and two YpR-infected hares scored positive for Y. pseudotuberculosis by means of bacteriological investigations. Grossly, suppurative multifocal lesions were detected in liver, spleen, kidney and sub-mandibular lymph nodes in both YpH- and YpR-infected hares and confirmed with histopathology. Pulmonary lesions were observed only in YpH-infected subjects. Immunohistochemistry confirmed the presence of bacterial antigen in all infected animals. Conclusion Results of this study revealed that YpH strain is more pathogenic for hares than the YpR strain; moreover the serological test performed in this study could be used for the diagnosis of pseudotuberculosis in hares, whereas post mortem diagnosis should be confirmed by means of bacteriological examination, PCR, histopathology and immunohistochemistry

Phenotypic and genotypic resistance to colistin in E. coli isolated from wild boar (Sus scrofa) hunted in Italy

The One Health approach is not only focused on diseases and zoonosis control but also on antimicrobial resistance. As concern this important issue, the problem of plasmid-mediated colistin resistance recently emerged. Few studies reported data about colistin resistance and mcr genes in bacteria from wildlife. In this manuscript, 168 Escherichia coli isolated from hunted wild boar were tested; colistin resistance was evaluated by MIC microdilution method, and the presence of mcr-1 and mcr-2 genes was evaluated by PCR. Overall, 27.9% of isolates resulted resistant to colistin, and most of them showed a MIC value > 256 μg/mL. A percentage of 44.6% of tested E. coli scored positive for one or both genes. In details, 13.6% of isolated harbored mcr-1 and mcr-2 in combination; most of them exhibiting the highest MIC values. Interestingly, 19.6% of mcr-positive E. coli resulted phenotypically susceptible to colistin. Wild boar could be considered a potential reservoir of colistin-resistant bacteria. In the light of the possible contacts with domestic animals and humans, this wild species could play an important role in the diffusion of colistin resistance. Thus, the monitoring programs on wildlife should include this aspect