The Roles and Interactions of Porphyromonas gingivalis and Fusobacterium nucleatum in Oral and Gastrointestinal Carcinogenesis: A Narrative Review.

Epidemiological studies have spotlighted the intricate relationship between individual oral bacteria and tumor occurrence. Porphyromonas gingivalis and Fusobacteria nucleatum, which are known periodontal pathogens, have emerged as extensively studied participants with potential pathogenic abilities in carcinogenesis. However, the complex dynamics arising from interactions between these two pathogens were less addressed. This narrative review aims to summarize the current knowledge on the prevalence and mechanism implications of P. gingivalis and F. nucleatum in the carcinogenesis of oral squamous cell carcinoma (OSCC), colorectal cancer (CRC), and pancreatic ductal adenocarcinoma (PDAC). In particular, it explores the clinical and experimental evidence on the interplay between P. gingivalis and F. nucleatum in affecting oral and gastrointestinal carcinogenesis. P. gingivalis and F. nucleatum, which are recognized as keystone or bridging bacteria, were identified in multiple clinical studies simultaneously. The prevalence of both bacteria species correlated with cancer development progression, emphasizing the potential impact of the collaboration. Regrettably, there was insufficient experimental evidence to demonstrate the synergistic function. We further propose a hypothesis to elucidate the underlying mechanisms, offering a promising avenue for future research in this dynamic and evolving field.

UHFUS: A Valuable Tool in Evaluating Exocrine Gland Abnormalities in Sjögren's Disease.

Sjögren's Disease (SjD) is a chronic autoimmune disorder that affects the salivary and lacrimal glands, leading to xerostomia and xerophthalmia. Ultrasonography of Major Salivary Glands (SGUS) is a well-established tool for the identification of the salivary glands' abnormalities in SjD. Recently, a growing interest has arisen in the assessment of the other exocrine glands with ultrasonography: lacrimal glands (LGUS) and labial salivary glands (LSGUS). The objective of this study is to explore the practical applications of ultra-high frequency ultrasound (UHFUS) in the assessment of lacrimal glands and labial salivary glands. Indeed, UHFUS, with its improved spatial resolution compared to conventional ultrasonography, allows for the evaluation of microscopic structures and has been successfully applied in various medical fields. In lacrimal glands, conventional high-frequency ultrasound (HFUS) can detect characteristic inflammatory changes, atrophic alterations, blood flow patterns, and neoplastic lesions associated with SjD. However, sometimes it is challenging to identify lacrimal glands characteristics, thus making UHFUS a promising tool. Regarding labial salivary glands, limited research is available with conventional HFUS, but UHFUS proves to be a good tool to evaluate glandular inhomogeneity and to guide labial salivary glands biopsy. The comprehensive understanding of organ involvement facilitated by UHFUS may significantly improve the management of SjD patients.

Fungal mycobiome-mediated immune response: a non-negligible promoter in pancreatic oncogenesis and chemoresistance.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers in humans due to late diagnosis and poor response to treatments. The tumor microenvironment (TME) of PDAC is characterized by a distinctive, suppressive immune profile, which inhibits the protective functions of anti-tumor immunity and thereby contributes to PDAC progression. Recently, the study of Alam et al. discovered for the first time that the intratumoral fungal mycobiome could contribute to the recruitment and activation of type 2 immune cells in the TME of PDAC via enhancing the secretion of a chemoattractant, interleukin (IL-) 33. In this article, we reviewed the important findings of this study. Together with our findings, we synthetically discussed the role of the fungal mycobiome in orchestrating the immune response and thereby modulating tumor progression.

Clinicopathological, cytogenetic, and molecular profiles of primary cutaneous diffuse large B-cell lymphomas.

We analyzed the clinicopathological, cytogenetic, and molecular features of 18 primary cutaneous diffuse large B-cell lymphomas (PCDLBCLs) and 15 DLBCLs secondarily localized to the skin (SCDLBCLs), highlighting biological similarities and differences between the 2 groups. PCDLBCLs were subclassified after histopathological review as PCDLBCL-leg type (PCDLBCL-LT, 10 cases) and the PCDLBCL-not otherwise specified (PCDLBCL-NOS, 8 cases). Immunohistochemistry for Hans' algorithm markers, BCL2, and MYC was performed. The molecular study included the determination of the cell of origin (COO) by Lymph2Cx assay on NanoString platform, FISH analysis of IgH, BCL2, BCL6, and MYC genes, as well as the mutation analysis of MYD88 gene. In immunohistochemistry analysis, BCL2 and MYC hyperexpression was more frequent in LT than in NOS cases and, according to Hans' algorithm, PCDLBCL-LTs were mostly of the non-GC type (8/10), whereas in PCDLBCL-NOS, the GC type prevailed (6/8). The determination of COO using Lymph2Cx supported and further confirmed these results. In FISH analysis, all but one LT cases versus 5 of 8 PCDLBCL-NOS showed at least one gene rearrangement among IgH, BCL2, MYC, or BCL6. In addition, MYD88 mutations were more frequently present in LT than in NOS subtypes. Interestingly, MYD88-mutated patients were older, with a non-GC phenotype and had worse OS, compared to MYD88 WT cases. Overall, SCDLBCL did not show, at the genetic and expression level, different profiles than PCDLBCL, even if they bear a significantly worse prognosis. At survival analysis, the most important prognostic factors in patients with PCDLBCL were age and MYD88 mutation, whereas relapse and high Ki-67 expression were relevant in patients with SCDLBCL. Our study comprehensively analyzed the clinicopathological and molecular features of PCDLBCL-LT, PCDLBCL-NOS, and SCDLBCL, underlining the differences among them and the importance of properly identifying these entities at the time of diagnosis.

Evidence of structural rearrangements in ESBL-positive pESI(like) megaplasmids of S.Infantis.

The increasing prevalence of pESI(like)-positive, multidrug-resistant (MDR) S. Infantis in Europe is a cause of major concern. As previously demonstrated, the pESI(like) megaplasmid is not only a carrier of antimicrobial resistant (AMR) genes (at least tet, dfr, and sul genes), but also harbours several virulence and fitness genes, and toxin/antitoxin systems that enhance its persistence in the S. Infantis host. In this study, five prototype pESI(like) plasmids, of either CTX-M-1 or CTX-M-65 ESBL-producing strains, were long-read sequenced using Oxford Nanopore Technology (ONT), and their complete sequences were resolved. Comparison of the structure and gene content of the five sequenced plasmids, and further comparison with previously published pESI(like) sequences, indicated that although the sequence of such pESI(like) 'mosaic' plasmids remains almost identical, their structures appear different and composed of regions inserted or transposed after different events. The results obtained in this study are essential to better understand the plasticity and the evolution of the pESI(like) megaplasmid, and therefore to better address risk management options and policy decisions to fight against AMR and MDR in Salmonella and other food-borne pathogens. Graphical representation of the pESI-like plasmid complete sequence (ID 12037823/11). Block colours indicate the function of the genes: red: repB gene; pink: class I integrons (IntI); yellow; mobile elements; blue: resistance genes; green: toxin/anti-toxin systems; grey: mer operon; light green: genes involve in conjugation.

Predicting lymphoma in Sjögren's syndrome and the pathogenetic role of parotid microenvironment through precise parotid swelling recording.

OBJECTIVE: Parotid swelling (PSW) is a major predictor of non-Hodgkin's lymphoma (NHL) in primary SS (pSS). However, since detailed information on the time of onset and duration of PSW is scarce, this was investigated to verify whether it may lead to further improved prediction. NHL localization was concomitantly studied to evaluate the role of the parotid gland microenvironment in pSS-related lymphomagenesis. METHODS: A multicentre study was conducted among patients with pSS who developed B cell NHL during follow-up and matched controls that did not develop NHL. The study focused on the history of salivary gland and lachrymal gland swelling, evaluated in detail at different times and for different durations, and on the localization of NHL at onset. RESULTS: PSW was significantly more frequent among the cases: at the time of first referred pSS symptoms before diagnosis, at diagnosis and from pSS diagnosis to NHL. The duration of PSW was evaluated starting from pSS diagnosis, and the NHL risk increased from PSW of 2-12 months to >12 months. NHL was prevalently localized in the parotid glands of the cases. CONCLUSION: A more precise clinical recording of PSW can improve lymphoma prediction in pSS. PSW as a very early symptom is a predictor, and a longer duration of PSW is associated with a higher risk of NHL. Since lymphoma usually localizes in the parotid glands, and not in the other salivary or lachrymal glands, the parotid microenvironment appears to be involved in the whole history of pSS and related lymphomagenesis.

Genomics insights into a Mycobacterium pinnipedii isolate causing tuberculosis in a captive South American sea lion (Otaria flavescens) from Italy.

Tuberculosis (TB) affects humans and other animals, and it is caused by bacteria within the Mycobacterium tuberculosis complex (MTBC). In this study, we report the characterisation of Mycobacterium pinnipedii that caused a TB case in a sea lion (Otaria flavescens) kept in an Italian zoo. The animal died due to severe, progressive disorders involving the respiratory and gastro-enteric systems and the skin. At necropsy, typical gross lesions referable to a TB generalised form were found. In particular, nodular granulomatous lesions were detected in the lungs and several lymph nodes, and colonies referable to Mycobacterium spp. were isolated from lung, mesenteric, and mediastinal lymph nodes. The isolate was identified by PCR as a MTBC, had a spoligotype SB 1480 ("seal lineage"), and was characterised and characterised by whole-genome sequencing analysis confirming that the MTBC involved was M. pinnipedii. The analysis of the resistome and virulome indicated the presence of macrolide and aminoglycoside resistance genes intrinsic in M. tuberculosis [erm-37 and aac(2')-Ic] and confirmed the presence of the region of difference 1 (RD1), harbouring the esxA and esxB virulence genes, differently from its closest taxon, M. microti. As for other MTCB members, M. pinnipedii infection can spill over into non-pinniped mammalian species; therefore, zoological gardens, veterinary practitioners, and public health officers should be aware of the hazard posed by tuberculosis from marine mammals. Since the isolate under study, as well as all available genomes of M. pinnipedii investigated in this study retains almost all the M. tuberculosis virulence genes, it could indeed cause infection, lesions, and disease in other animal species, including humans.

Glandular involvement in primary Sjögren's syndrome patients with interstitial lung disease-onset and sicca-onset, a single centre cross-sectional study.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is an autoimmune exocrinopathy classically presenting with sicca symptoms. Nonetheless, disease onset with extraglandular manifestations, including interstitial lung disease (ILD), is increasingly reported. However, studies investigating pSS patients presenting with ILD (pSS-ILD) are limited.Aim of this study was to better characterise the phenotype of pSS patients presenting with ILD in comparison to pSS patients with classicsicca-onset. We especially investigated whether the two groups differed in glandular involvement comparing functional, imaging andhistologic findings, as well as patient reported outcome (PRO). METHODS: Consecutive newly diagnosed pSS patients, all fulfilling the ACR/EULAR 2016 criteria, were included in this cross-sectional study from September 2016 to October 2021. Presence of ILD at pSS diagnosis was defined based on clinical findings, imaging assessment and pulmonary function tests (PFT). In addition to functional tests, a minor salivary gland biopsy was performed in all cases, recording number of foci, focus score (FS) and GC-like structures. Salivary glands ultrasonography (SGUS) was graded using the OMERACT semiquantitative scoring system (0-3) based on parenchyma inhomogeneity. PRO including ESSPRI, OHIP and OSSDI were collected.Extraglandular clinical features and biological abnormalities included in the ESSDAI were recorded. Data were expressed as mean±SD for continuous variables and as absolute frequencies and percentages for categorical variables. Chi-Square test and Mann-Whitney U-test and ANOVA were performed for comparisons of categorical variables and continuous variables, respectively. RESULTS: We included 178 newly diagnosed pSS patients (F:M=158:20). ILD was the first pSS manifestation in 11 (6%) cases, 8 F and 3 M, with a median time from ILD onset to pSS diagnosis of 2 years (25-75 IQ 1-4.5). Of the 11 pSS-ILD patients, HRCT pattern was defined as NSIP in 4, UIP in 4, NSIP+OP in 2 and LIP in 1 patient. Dyspnoea on exertion or chronic cough were reported by 7/11 (63.6%) patients.In comparison to sicca-onset patients, pSS-ILD patients presented an older age at diagnosis (55±13 vs. 70±7, p= 0.001) and a higher ESSDAI (3.9±4.7 vs. 12.3±4.3, p=0.001), driven by the pulmonary domain. Regarding glandular involvement, pSS-ILD patients reported milder xeropthalmia (VAS 5.8±3.1 vs. 2.8±3.5, p=0.002) and significative lower scores in OSDI (35.6±24.9 vs. 15.3±22.9, p=0.04) and OHIP (4.8±4.4 vs. 1.4±3.8, p=0.04), despite no significant differences observed between the two groups in ocular tests and unstimulated salivary flow rate. With respect to histology, no significant differences were found in number of foci, FS and GC-like structures. We observed a significantly different distribution of the SGUS OMERACT score in the two groups: none of pSS-ILD patients presented a SGUS OMERACT score ≥2 in the submandibular glands (SG), in contrast to 41/132 (31.1%) of the patients in the classical sicca-onset group (p=0.03). Finally, no significant differences were observed between the two groups with respect to non-pulmonary extraglandular manifestations, serologic features and other biological parameters. CONCLUSIONS: ILD-onset pSS patients represent an atypical phenotypic subset, with less pronounced sialadenitis structural changes in salivary glands, and with sicca symptoms probably overshadowed by the respiratory disease.

Role of drug catabolism, modulation of oncogenic signaling and tumor microenvironment in microbe-mediated pancreatic cancer chemoresistance.

Pancreatic ductal adenocarcinoma (PDAC) has one of the highest incidence/death ratios among all neoplasms due to its late diagnosis and dominant chemoresistance. Most PDAC patients present with an advanced disease characterized by a multifactorial, inherent and acquired resistance to current anticancer treatments. This remarkable chemoresistance has been ascribed to several PDAC features including the genetic landscape, metabolic alterations, and a heterogeneous tumor microenvironment that is characterized by dense fibrosis, and a cellular contexture including functionally distinct subclasses of cancer-associated fibroblasts, immune suppressive cells, but also a number of bacteria, shaping a specific tumor microbiome microenvironment. Thus, recent studies prompted the emergence of a new research avenue, by describing the role of the microbiome in gemcitabine resistance, while next-generation-sequencing analyses identified a specific microbiome in different tumors, including PDAC. Functionally, the contribution of these microbes to PDAC chemoresistance is only beginning to be explored. Here we provide an overview of the studies demonstrating that bacteria have the capacity to metabolically transform and hence inactivate anticancer drugs, as exemplified by the inhibition of the efficacy of 10 out of 30 chemotherapeutics by Escherichia coli. Moreover, a number of bacteria modulate specific oncogenic pathways, such as Fusobacterium nucleatum, affecting autophagy and apoptosis induction by 5-fluorouracil and oxaliplatin. We hypothesize that improved understanding of how chemoresistance is driven by bacteria could enhance the efficacy of current treatments, and discuss the potential of microbiome modulation and targeted therapeutic approaches as well as the need for more reliable models and biomarkers to translate the findings of preclinical/translational research to the clinical setting, and ultimately overcome PDAC chemoresistance, hence improving clinical outcome.

Connexin Expression in Human Minor Salivary Glands: An Immunohistochemical Microscopy Study.

Connexins (Cxs) are transmembrane proteins involved in the formation of hemichannels and gap junctions (GJs). GJs are involved in various physiological functions, including secretion in glandular tissue. It has been demonstrated that Cx26, Cx32, and Cx43 are mainly expressed in glands, but no data are available in human salivary glands to date. The aim of our study was to investigate the presence and the localization of Cxs in human minor labial salivary glands. Immunofluorescence and immunoelectron microscopy were employed to evaluate the Cx26, Cx32, and Cx43 protein in human labial salivary gland biopsies (hLSGBs). RT-PCR was also used to detect their mRNA expression. Cx expression was found at both the mRNA and protein levels in all hLSGBs analysed. Cxs were observed at the level of the duct and acinar cells, as well as in myoepithelial cells. The localization of the three Cx types was very similar, suggesting colocalization of these Cxs in the same connexons. These results demonstrated the presence of Cxs in human salivary glands for the first time. Moreover, the few samples with primary Sjögren's Syndrome analysed only by immunofluorescence showed an alteration of the Cx expression, indicating that these proteins could be involved in salivary gland dysfunctions.

Reversible mutations in gliding motility and virulence genes: A flexible and efficient phage defence mechanism in Flavobacterium psychrophilum.

Flavobacteria are among the most important pathogens in freshwater salmonid aquaculture worldwide. Due to concerns regarding development of antibiotic resistance, phage therapy has been proposed as a solution to decrease pathogen load. However, application of phages is challenged by the development of phage resistance, and knowledge of the mechanisms and implications of phage resistance is therefore required. To study this, 27 phage-resistant isolates of F. psychrophilum were genome sequenced and characterized to identify genetic modifications and evaluate changes in phenotypic traits, including virulence against rainbow trout. Phage-resistant isolates showed reduction or loss of gliding motility, proteolytic activity, and adhesion to surfaces, and most isolates were completely non-virulent against rainbow trout fry. Genomic analysis revealed that most phage-resistant isolates had mutations in genes associated with gliding motility and virulence. Reversal of these mutations in a sub-set of isolates led to regained motility, proteolytic activity, virulence and phage susceptibility. Although costly, the fast generation of phage resistance driven by single, reversible mutations likely represents a flexible and efficient phage defence mechanism in F. psychrophilum. The results further suggest that phage administration in aquaculture systems to prevent F. psychrophilum outbreaks selects for non-virulent phage-resistant phenotypes.

Nasopharyngeal sarcoidosis: case reports and literature review.

Sarcoidosis is a multisystemic inflammatory chronic disease characterized by the presence of noncaseating granulomas most frequently in lungs and in intrathoracic lymph nodes. The nasopharyngeal form is unusual and noncommon in the ENT practice. Background and objectives: In order to establish a correct knowledge about this rare disease, we report two different cases of nasopharyngeal sarcoidosis moreover all the available literature is reviewed. Materials and Methods: A systematic literature review was made through PubMed databases, according to the PRISMA guidelines (1), combining the following key words: Nasopharyngeal, Rhinopharynx, Sarcoidosis, in publications between 1951 and 2020. In addition, we reported our personal experience on the disease by describing two clinical cases that occurred at our clinic in November 2018 and June 2019. Results: 16 articles reported 27 cases of nasopharyngeal sarcoidosis. The number of males was 13 (48,2%) and the number of females was 14 (51,8%) with a mean age at the diagnosis of 35,28 ± 13.05 years old (range 5 - 64). In 16 (59,3%) cases nasopharyngeal sarcoidosis was associated with lungs and/or intrathoracic lymph nodes involvement; nasal obstruction was the most frequently reported symptom (51,8% of subjects). Conclusions: Nasopharyngeal sarcoidosis can mimic several disorders of the upper airway respiratory tract and it must therefore be considered in the differential diagnosis. A biopsy of nonspecific lesions in the nasopharynx is advisable to permit several early diagnosis of upper airway respiratory tract disorders including sarcoidosis.

The Gut Microbiota of Healthy and Flavobacterium psychrophilum-Infected Rainbow Trout Fry Is Shaped by Antibiotics and Phage Therapies.

In the aquaculture sector, there is an increased interest in developing environmentally friendly alternatives to antibiotics in the treatment and prevention of bacterial infections. This requires an understanding of the effects of different treatments on the fish microbiota as a measure for improving the fish health status. In this study, we focused on the freshwater pathogen Flavobacterium psychrophilum and investigated the effects of antibiotics (florfenicol) and phage therapies on the gut microbiota of healthy and infected rainbow trout fry (1-2 g). Florfenicol-coated feed was administered for 10 days, starting two days after the infection procedure. A two-component mix of phage targeting F. psychrophilum (FpV4 and FPSV-D22) was continuously delivered by feed with a prophylactic period of 12 days. Samples of the distal intestine were collected over time (day -1 and 1, 8, and 33 days post-infection) and analyzed by community analysis targeting the 16S rRNA gene (V3-V4 region). Results showed the dysbiosis effect caused both by the infection and by florfenicol administration. Shifts in the overall composition were detected by ß-diversity analysis, and changes in specific populations were observed during taxonomic mapping. Measures of α-diversity were only affected in infected fish (large variation observed 1 and 8 dpi). These community alterations disappeared again when fish recovered from the infection and the antibiotic treatment was terminated (33 dpi). Interestingly, phage addition altered the microbiota of the fish independently of the presence of their target bacterium. The overall gut bacterial community in fish fed phage-treated feed was different from the controls at each time point as revealed by ß-diversity analysis. However, it was not possible to identify specific bacterial populations responsible for these changes except for an increase of lactic acid bacteria 33 dpi. Overall, the results indicate that the administered phages might affect the complex network of phage-bacteria interactions in the fish gut. Nevertheless, we did not observe negative effects on fish health or growth, and further studies should be directed in understanding if these changes are beneficial or not for the fish health with an additional focus on the host immune response.

Myeloid neoplasms and autoimmune diseases: markers of association.

OBJECTIVES: To investigate the prognostic significance of concomitant autoimmune diseases (ADs) in myeloproliferative neoplasms (MPNs). METHODS: 435 subjects with a diagnosis of MPNs were included in this observational single institution longitudinal study. Of them, 34 patients presented an overt AD at diagnosis of MPN. Clinical presenting features, progression-free and overall survival were compared between MPN subgroups in relation to co-existence of AD at diagnosis of MPN. RESULTS: Compared to cases without ADs, the subjects with ADs were significantly younger, had lower haemoglobin and haematocrit levels and more frequently presented with splenomegaly. The clinical and biological features associated to progression-free and overall survival were: age, presence of splenomegaly, histotype (MF vs. PV vs. ET), anaemia, high platelet count and presence of any AD at diagnosis of MPN. The age-adjusted hazard ratio (HR) of progression for the presence of AD at diagnosis of MPN was 2.76. Overall survival was not significantly associated to AD at diagnosis, but the HR of progression for the presence of AD at diagnosis of MPN was 2.18. CONCLUSIONS: A possible common genetic predisposition, the inflammatory bone marrow microenvironment and the activation of theJAK/STAT pathway could be considered as responsible for the observed association between MPNs and ADs.

Factors influencing intraoperative blood loss and hemoglobin drop during laparoscopic myomectomy: a tailored approach is possible?

A retrospective study was conducted on patients subjected to laparoscopic myomectomy at our institution from January 2017 to December 2018 to identify predictive factors of blood loss. Two multiple regression models were run to predict intraoperative blood loss and haemoglobin drop. Predictors of an increased intraoperative blood loss and haemoglobin drop were the presence of three-four fibroids at ultrasound (+47 ml, p = .01; +0.58 g/dl, p = .05) and increased operative time (r = 0.57, p = .01; r = 0.01, p < .01), while predictors of a reduced intraoperative blood loss and haemoglobin drop were epinephrine injection (-50 ml, p < .01; -0.42 g/dl, p < .01), FIGO7 (-87 ml, p < .01; -0.85, p = .01), and FIGO6 (-35 ml, p < .01; -0.44, p = .02) fibroids at the ultrasound. Preoperative ultrasound evaluation is crucial in identifying patients at higher risk for blood loss, which could benefit from optimising haemoglobin values. The injection of diluted epinephrine could be proposed in selected high-risk patients. In the clinical practice, a tailored approach based on fibroids' ultrasonographic characteristics should be implemented to optimise preoperative Hb values and evaluate the use of diluted epinephrine in selected cases, reducing blood loss and the potential related complications.Impact statementWhat is already known on this subject? Laparoscopic myomectomy is the conservative surgical treatment of choice for symptomatic uterine fibroids. Still, it could represent a challenging procedure even for an experienced surgeon, with the risk of excessive blood loss, need of transfusions, prolonged operative time, and prolonged hospital stay. The knowledge of the predictive factors of blood loss is essential for patient preparation and surgical planning to reduce intraoperative and postoperative complications.What do the results of this study add? The results of the present study focus on the importance of presurgical evaluation to identify predictive factors of intraoperative blood loss and Hb drop such as the number of fibroids and the FIGO classification (at preoperative ultrasound), as well as intraoperative factors like operative time and the intramyometrial injection of diluted epinephrine.What are the implications of these findings for clinical practice and/or further research? A tailored approach based on the ultrasonographic characteristics of fibroids should be implemented to optimise preoperative haemoblobin levels.

Emergence of IncHI2 Plasmids With Mobilized Colistin Resistance (mcr)-9 Gene in ESBL-Producing, Multidrug-Resistant Salmonella Typhimurium and Its Monophasic Variant ST34 From Food-Producing Animals in Italy.

A collection of 177 genomes of Salmonella Typhimurium and its monophasic variant isolated in 2014-2019 from Italian poultry/livestock (n = 165) and foodstuff (n = 12), previously screened for antimicrobial susceptibility and assigned to ST34 and single-locus variants, were studied in-depth to check the presence of the novel mcr-9 gene and to investigate their genetic relatedness by whole genome sequencing (WGS). The study of accessory resistance genes revealed the presence of mcr-9.1 in 11 ST34 isolates, displaying elevated colistin minimum inhibitory concentration values up to 2 mg/L and also a multidrug-resistant (MDR) profile toward up to seven antimicrobial classes. Five of them were also extended-spectrum beta-lactamases producers (bla SHV - 12 type), mediated by the corresponding antimicrobial resistance (AMR) accessory genes. All mcr-9-positive isolates harbored IncHI2-ST1 plasmids. From the results of the Mash analysis performed on all 177 genomes, the 11 mcr-9-positive isolates fell together in the same subcluster and were all closely related. This subcluster included also two mcr-9-negative isolates, and other eight mcr-9-negative ST34 isolates were present within the same parental branch. All the 21 isolates within this branch presented an IncHI2/2A plasmid and a similar MDR gene pattern. In three representative mcr-9-positive isolates, mcr-9 was demonstrated to be located on different IncHI2/IncHI2A large-size (∼277-297 kb) plasmids, using a combined Illumina-Oxford Nanopore WGS approach. These plasmids were also compared by BLAST analysis with publicly available IncHI2 plasmid sequences harboring mcr-9. In our plasmids, mcr-9 was located in a ∼30-kb region lacking different genetic elements of the typical core structure of mcr-9 cassettes. In this region were also identified different genes involved in heavy metal metabolism. Our results underline how genomics and WGS-based surveillance are increasingly indispensable to achieve better insights into the genetic environment and features of plasmid-mediated AMR, as in the case of such IncHI2 plasmids harboring other MDR genes beside mcr-9, that can be transferred horizontally also to other major Salmonella serovars spreading along the food chain.

Comparative Genomic Analyses of Flavobacterium psychrophilum Isolates Reveals New Putative Genetic Determinants of Virulence Traits.

The fish pathogen Flavobacterium psychrophilum is currently one of the main pathogenic bacteria hampering the productivity of salmonid farming worldwide. Although putative virulence determinants have been identified, the genetic basis for variation in virulence of F. psychrophilum is not fully understood. In this study, we analyzed whole-genome sequences of a collection of 25 F. psychrophilum isolates from Baltic Sea countries and compared genomic information with a previous determination of their virulence in juvenile rainbow trout. The results revealed a conserved population of F. psychrophilum that were consistently present across the Baltic Sea countries, with no clear association between genomic repertoire, phylogenomic, or gene distribution and virulence traits. However, analysis of the entire genome of four F. psychrophilum isolates by hybrid assembly provided an unprecedented resolution for discriminating even highly related isolates. The results showed that isolates with different virulence phenotypes harbored genetic variances on a number of consecutive leucine-rich repeat (LRR) proteins, repetitive motifs in gliding motility-associated protein, and the insertion of transposable elements into intergenic and genic regions. Thus, these findings provide novel insights into the genetic variation of these elements and their putative role in the modulation of F. psychrophilum virulence.

A biomarker for lymphoma development in Sjogren's syndrome: Salivary gland focus score.

The aim of this study is to explore the role of labial minor salivary gland (LMSG) focus score (FS) in stratifying Sjögren's Syndrome (SS) patients, lymphoma development prediction and to facilitate early lymphoma diagnosis. Ιn an integrated cohort of 1997 patients, 618 patients with FS ≥ 1 and at least one-year elapsing time interval from SS diagnosis to lymphoma diagnosis or last follow up were identified. Clinical, laboratory and serological features were recorded. A data driven logistic regression model was applied to identify independent lymphoma associated risk factors. Furthermore, a FS threshold maximizing the difference of time interval from SS until lymphoma diagnosis between high and low FS lymphoma subgroups was investigated, to develop a follow up strategy for early lymphoma diagnosis. Of the 618 patients, 560 were non-lymphoma SS patients while the other 58 had SS and lymphoma. FS, cryoglobulinemia and salivary gland enlargement (SGE) were proven to be independent lymphoma associated risk factors. Lymphoma patients with FS ≥ 4 had a statistically significant shorter time interval from SS to lymphoma diagnosis, compared to those with FS < 4 (4 vs 9 years, respectively, p = 0,008). SS patients with FS ≥ 4 had more frequently B cell originated manifestations and lymphoma, while in patients with FS < 4, autoimmune thyroiditis was more prevalent. In the latter group SGE was the only lymphoma independent risk factor. A second LMSG biopsy is patients with a FS ≥ 4, 4 years after SS diagnosis and in those with FS < 4 and a history of SGE, at 9-years, may contribute to an early lymphoma diagnosis. Based on our results we conclude that LMSG FS, evaluated at the time of SS diagnosis, is an independent lymphoma associated risk factor and may serve as a predictive biomarker for the early diagnosis of SS-associated lymphomas.