Scientometrics Evaluation of Published Scientific Papers on the Use of Proteomics Technologies in Mastitis Research in Ruminants.

The objective of this study was the presentation of quantitative characteristics regarding the scientific content and bibliometric details of the relevant publications. In total, 156 papers were considered. Most papers presented original studies (n = 135), and fewer were reviews (n = 21). Most original articles (n = 101) referred to work involving cattle. Most original articles described work related to the diagnosis (n = 72) or pathogenesis (n = 62) of mastitis. Most original articles included field work (n = 75), whilst fewer included experimental (n = 31) or laboratory (n = 30) work. The tissue assessed most frequently in the studies was milk (n = 59). Milk was assessed more frequently in studies on the diagnosis (61.1% of relevant studies) or pathogenesis (30.6%) of the infection, but mammary tissue was assessed more frequently in studies on the treatment (31.0%). In total, 47 pathogens were included in the studies described; most were Gram-positive bacteria (n = 34). The three bacteria most frequently included in the studies were Staphylococcus aureus (n = 55 articles), Escherichia coli (n = 31) and Streptococcus uberis (n = 19). The proteomics technology employed more often in the respective studies was liquid chromatography-tandem mass spectrometry (LC-MS/MS), either on its own (n = 56) or in combination with other technologies (n = 40). The median year of publication of articles involving bioinformatics or LC-MS/MS and bioinformatics was the most recent: 2022. The 156 papers were published in 78 different journals, most frequently in the Journal of Proteomics (n = 16 papers) and the Journal of Dairy Science (n = 12). The median number of cited references in the papers was 48. In the papers, there were 1143 co-authors (mean: 7.3 ± 0.3 co-authors per paper, median: 7, min.-max.: 1-19) and 742 individual authors. Among them, 15 authors had published at least seven papers (max.: 10). Further, there were 218 individual authors who were the first or last authors in the papers. Most papers were submitted for open access (n = 79). The median number of citations received by the 156 papers was 12 (min.-max.: 0-339), and the median yearly number of citations was 2.0 (min.-max.: 0.0-29.5). The h-index of the papers was 33, and the m-index was 2. The increased number of cited references in papers and international collaboration in the respective study were the variables associated with most citations to published papers. This is the first ever scientometrics evaluation of proteomics studies, the results of which highlighted the characteristics of published papers on mastitis and proteomics. The use of proteomics in mastitis research has focused on the elucidation of pathogenesis and diagnosis of the infection; LC-MS/MS has been established as the most frequently used proteomics technology, although the use of bioinformatics has also emerged recently as a useful tool.

APRF1 Interactome Reveals HSP90 as a New Player in the Complex That Epigenetically Regulates Flowering Time in Arabidopsis thaliana.

WD40 repeat proteins (WDRs) are present in all eukaryotes and include members that are implicated in numerous cellular activities. They act as scaffold proteins and thus as molecular "hubs" for protein-protein interactions, which mediate the assembly of multifunctional complexes that regulate key developmental processes in Arabidopsis thaliana, such as flowering time, hormonal signaling, and stress responses. Despite their importance, many aspects of their putative functions have not been elucidated yet. Here, we show that the late-flowering phenotype of the anthesis promoting factor 1 (aprf1) mutants is temperature-dependent and can be suppressed when plants are grown under mild heat stress conditions. To gain further insight into the mechanism of APRF1 function, we employed a co-immunoprecipitation (Co-IP) approach to identify its interaction partners. We provide the first interactome of APRF1, which includes proteins that are localized in several subcellular compartments and are implicated in diverse cellular functions. The dual nucleocytoplasmic localization of ARRF1, which was validated through the interaction of APRF1 with HEAT SHOCK PROTEIN 1 (HSP90.1) in the nucleus and with HSP90.2 in the cytoplasm, indicates a dynamic and versatile involvement of APRF1 in multiple biological processes. The specific interaction of APRF1 with the chaperon HSP90.1 in the nucleus expands our knowledge regarding the epigenetic regulation of flowering time in A. thaliana and further suggests the existence of a delicate thermoregulated mechanism during anthesis.

Indication of West Nile Virus (WNV) Lineage 2 Overwintering among Wild Birds in the Regions of Peloponnese and Western Greece.

West Nile virus (WNV), a zoonotic mosquito-borne virus, has recently caused human outbreaks in Europe, including Greece. Its transmission cycle in nature includes wild birds as amplifying hosts and ornithophilic mosquito vectors. The aim of this study was to assess WNV circulation among wild birds from two regions of Greece, Peloponnese and Western Greece, during 2022. To this end, a total of 511 birds belonging to 37 different species were sampled and molecularly screened. WNV RNA was detected from February to November in a total of 71 wild birds of nine species originating from both investigated regions. The first eight positive samples were sequenced on a part of NS3 and, according to the phylogenetic analysis, they belonged to evolutionary lineage 2 and presented similarity to previous outbreak-causing Greek strains (Argolis 2017, Macedonia 2010 and 2012). It was more likely to identify a PCR positive bird as the population density and the distance from water sources decreased. The present report provides evidence of WNV occurrence in both Peloponnese and Western Greece during 2022 and underlines its possible overwintering, highlighting the need for avian species surveillance to be conducted annually and throughout the year. Magpies are proposed as sentinels for WNV monitoring.

GUS Reporter-Aided Promoter Deletion Analysis of A. thaliana POLYAMINE OXIDASE 3.

Polyamine oxidases (PAOs) have been correlated with numerous physiological and developmental processes, as well as responses to biotic and abiotic stress conditions. Their transcriptional regulation is driven by signals generated by various developmental and environmental cues, including phytohormones. However, the inductive mechanism(s) of the corresponding genes remains elusive. Out of the five previously characterized Arabidopsis PAO genes, none of their regulatory sequences have been analyzed to date. In this study, a GUS reporter-aided promoter deletion approach was used to investigate the transcriptional regulation of AtPAO3 during normal growth and development as well as under various inductive environments. AtPAO3 contains an upstream open reading frame (uORF) and a short inter-cistronic sequence, while the integrity of both appears to be crucial for the proper regulation of gene expression. The full-length promoter contains several cis-acting elements that regulate the tissue-specific expression of AtPAO3 during normal growth and development. Furthermore, a number of TFBS that are involved in gene induction under various abiotic stress conditions display an additive effect on gene expression. Taken together, our data indicate that the transcription of AtPAO3 is regulated by multiple environmental factors, which probably work alongside hormonal signals and shed light on the fine-tuning mechanisms of PAO regulation.

Over-expression of GGP1 and GPP genes enhances ascorbate content and nutritional quality of tomato.

L-Ascorbic acid (AsA), a strong antioxidant, serves as an enzyme cofactor and redox status marker, modulating a plethora of biological processes. As tomato commercial varieties and hybrids possess relatively low amounts of AsA, the improvement of fruit AsA represents a strategic goal for enhanced human health. Previously, we have suggested that GDP-L-Galactose phosphorylase (GGP) and L-galactose-1-phosphate phosphatase (GPP) can serve as possible targets for AsA manipulation in tomato (Solanum lycopersicon L.) fruit. To this end, we produced and evaluated T3 transgenic tomato plants carrying these two genes under the control of CaMV-35S and two fruit specific promoters, PPC2 and PG-GGPI. The transgenic lines had elevated levels of AsA, with the PG-GGP1 line containing 3-fold more AsA than WT, without affecting fruit characteristics. Following RNA-Seq analysis, 164 and 13 DEGs were up- or down-regulated, respectively, between PG-GGP1 and WT pink fruits. PG-GGP1 fruit had a distinct number of up-regulated transcripts associated with cell wall modification, ethylene biosynthesis and signaling, pollen fertility and carotenoid metabolism. The elevated AsA accumulation resulted in the up regulation of AsA associated transcripts and alternative biosynthetic pathways suggesting that the entire metabolic pathway was influenced, probably via master regulation. We show here that AsA-fortification of tomato ripe fruit via GGP1 overexpression under the action of a fruit specific promoter PG affects fruit development and ripening, reduces ethylene production, and increased the levels of sugars, and carotenoids, supporting a robust database to further explore the role of AsA induced genes for agronomically important traits, breeding programs and precision gene editing approaches.

West Nile Virus Occurrence and Ecological Niche Modeling in Wild Bird Species and Mosquito Vectors: An Active Surveillance Program in the Peloponnese Region of Greece.

West Nile Virus (WNV) is maintained in nature in a bird-mosquito cycle and human infections follow a seasonal pattern, favored by climatic conditions. Peloponnese Region, located in Southern Greece, initiated an active WNV surveillance program to protect public health during 2019-2020. The project included monitoring of avian hosts and mosquito vectors, while sampling locations were prioritized after consideration of WNV circulation in birds, mosquitos and humans during previous seasons. Biological materials were collected from 493 wild birds of 25 species and 678 mosquito pools, which were molecularly screened for WNV presence. In this case, 14 environmental variables were associated with WNV detection in wild birds and mosquitos by using two separate MaxEnt models. Viral RNA was not detected in the target species during 2019, although in 2020, it was reported on 46 wild birds of ten species and 22 mosquito pools (Culex pipiens and Aedes albopictus). Altitude and land uses were significant predictors for both models and in fact, suitable conditions for virus occurrence were identified in low altitude zones. Bird- and mosquito-based surveillance systems yielded similar results and allowed for targeted vector control applications in cases of increased virus activity. Human cases were not reported on Peloponnese in 2020.

Development of a Multiplex Bead Assay to Detect Serological Responses to Brucella Species in Domestic Pigs and Wild Boar with the Potential to Overcome Cross-Reactivity with Yersinia enterocolitica O:9.

The aim of this study was to develop a multiplex bead assay using a Brucella rLPS antigen, a Brucella suis smooth antigen, and a Yersinia enterocolitica O:9 antigen that not only discriminates Brucella-infected from Brucella-uninfected pigs and wild boar, but also overcomes the cross reactivity with Y. enterocolitica O:9. Sera from 126 domestic pigs were tested: 29 pigs were Brucella infected, 80 were non-infected and 17 were confirmed to be false positive serological reactors (FPSR). Sera from 49 wild boar were tested: 18 were positive and 31 were negative. Using the rLPS antigen, 26/29 Brucella-infected domestic pigs and 15/18 seropositive wild boar were positive, while 75/80 non-Brucella infected domestic pigs, all FPSR, and all seronegative wild boar were negative. Using the smooth B. suis 1330 antigen, all Brucella-infected domestic pigs, 9/17 FPSR and all seropositive wild boar were positive, while all non-infected pigs and 30/31 seronegative wild boar were negative. The ratio of the readouts from the smooth B. suis antigen and Y. enterocolitica O:9 antigen enabled discriminating all Brucella infected individuals from the FPSR domestic pigs. These results demonstrate the potential of this assay for use in the surveillance of brucellosis, overcoming the cross-reactivity with Y. enterocolitica.

Occurrence and Characteristics of ESBL- and Carbapenemase- Producing Escherichia coli from Wild and Feral Birds in Greece.

Wild and feral birds are known to be involved in the maintenance and dissemination of clinically-important antimicrobial-resistant pathogens, such as extended-spectrum ß-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae. The aim of our study was to evaluate the presence of ESBL- and carbapenemase-producing Escherichia coli among wild and feral birds from Greece and to describe their antimicrobial resistance characteristics. In this context, fecal samples of 362 birds were collected and cultured. Subsequently, the antimicrobial resistance pheno- and geno-type of all the obtained E. coli isolates were determined. A total of 12 multidrug-resistant (MDR), ESBL-producing E. coli were recovered from eight different wild bird species. Eleven of these isolates carried a blaCTX-M-1 group gene alone or in combination with blaTEM and one carried only blaTEM. AmpC, fluoroquinolone, trimethoprim/sulfamethoxazole, aminoglycoside and macrolide resistance genes were also detected. Additionally, one carbapenemase-producing E. coli was identified, harboring blaNDM along with a combination of additional resistance genes. This report describes the occurrence of ESBL- and carbapenemase-producing E. coli among wild avian species in Greece, emphasizing the importance of incorporating wild birds in the assessment of AMR circulation in non-clinical settings.

Isolation of Listeria ivanovii from Bulk-Tank Milk of Sheep and Goat Farms-From Clinical Work to Bioinformatics Studies: Prevalence, Association with Milk Quality, Antibiotic Susceptibility, Predictors, Whole Genome Sequence and Phylogenetic Relationships.

A cross-sectional study was performed in 325 sheep and 119 goat dairy farms in Greece. Samples of bulk-tank milk were examined by standard microbiological techniques for Listeria spp. Listeria monocytogenes was isolated from one (0.3%) and Listeria ivanovii from three (0.9%) sheep farms. No associations between the isolation of L. monocytogenes or L. ivanovii and milk quality were found. No resistance to antibiotics was identified. Three variables emerged as significant predictors of isolation of the organism: the presence of pigs, low average relative humidity and a high number of ewes on the farm. The three L. ivanovii isolates were assessed in silico for identification of plasmids, prophages, antibiotic resistance genes, virulence factors, CRISPRs and CAS genes. Phylogenetic analysis using the core genome revealed that the three strains belonged to the L. ivanovii subsp. ivanovii branch and were especially close to the PAM 55 strain. All strains of the branch appeared to be very similar, with the distance between them being small.

Cross-Sectional Survey of Antibiotic Resistance in Extended Spectrum ß-Lactamase-Producing Enterobacteriaceae Isolated from Pigs in Greece.

This study aimed to estimate the prevalence of extended-spectrum ß-lactamase-producing (ESBL) bacteria in swine. Thus, 214 fecal samples were collected from suckling and weaned piglets from 34 farms in Greece (out of an overall population of about 14,300 sows). A subset of 78 (36.5%) ESBL producers were identified as E. coli (69/78, 88.5%), K. pneumoniae spp. pneumoniae (3.8%), P. mirabilis (5.1%), E. cloacae complex (1.3%) and S. enterica spp. diarizonae (1.3%). Resistance to at least one class of non-ß-lactam antibiotics was detected in 78 isolates. Among the E. coli strains, resistance was identified with regard to aminoglycosides (n = 31), fluoroquinolones (n = 49), tetracycline (n = 26) and trimethoprim/sulfamethoxazole (n = 46). Of the three K. pneumoniae spp. pneumoniae, two displayed resistances to aminoglycosides and all were resistant to fluoroquinolones, tetracyclines and trimethoprim/sulfamethoxazole. As for the four P. mirabilis isolates, three had a resistant phenotype for aminoglycosides and all were resistant to imipenem, fluoroquinolones, tetracyclines and trimethoprim/sulfamethoxazole. Molecular characterization of the isolates revealed the presence of CTX-M, SHV and TEM genes, as well as of genes conferring resistance to fluoroquinolones, aminoglycosides, sulfonamides, trimethoprim, macrolides and colistin. High levels of antimicrobial resistance (AMR) were demonstrated in Greek swine herds posing a concern for the efficacy of treatments at the farm level as well as for public health.

ESBL-Producing Moellerella wisconsensis-The Contribution of Wild Birds in the Dissemination of a Zoonotic Pathogen.

Moellerella wisconsensis is an Enterobacteriaceae with unclarified dispersion and pathogenicity. During an ongoing investigation about antimicrobial resistance in Greece, the occurrence of M. wisconsensis was evaluated among wild birds and humans. A total of 445 wild bird and 2000 human fecal samples were collected and screened for the presence of the organism. Subsequently, all M. wisconsensis strains were phenotypically and molecularly characterized regarding their antimicrobial resistance characteristics. Four M. wisconsensis were isolated from a common pheasant (Phasianus colchicus), two Eurasian magpies (Pica pica) and a great white-fronted goose (Anser albifrons). Among these four strains, the three latter presented resistance to 3rd generation cephalosporins, were phenotypically confirmed to produce ESBLs and were found to harbor blaCTX-M-1. The three ESBL isolates additionally exhibited resistance to tetracyclines, while resistance to aminoglycosides was detected in two of them and to trimethoprim/sulfamethoxazole in one. No Moellerella wisconsensis strains were retrieved from the human samples tested. This is the first report that provides evidence of M. wisconsensis dissemination among wild birds in Greece, describing CTX-M-1 production in multidrug resistant wild birds' isolates of this bacterial species.

Clavibacter michiganensis Downregulates Photosynthesis and Modifies Monolignols Metabolism Revealing a Crosstalk with Tomato Immune Responses.

The gram-positive pathogenic bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial canker disease in tomato, affecting crop yield and fruit quality. To understand how tomato plants respond, the dynamic expression profile of host genes was analyzed upon Cmm infection. Symptoms of bacterial canker became evident from the third day. As the disease progressed, the bacterial population increased in planta, reaching the highest level at six days and remained constant till the twelfth day post inoculation. These two time points were selected for transcriptomics. A progressive down-regulation of key genes encoding for components of the photosynthetic apparatus was observed. Two temporally separated defense responses were observed, which were to an extent interdependent. During the primary response, genes of the phenylpropanoid pathway were diverted towards the synthesis of monolignols away from S-lignin. In dicots, lignin polymers mainly consist of G- and S-units, playing an important role in defense. The twist towards G-lignin enrichment is consistent with previous findings, highlighting a response to generate an early protective barrier and to achieve a tight interplay between lignin recomposition and the primary defense response mechanism. Upon progression of Cmm infection, the temporal deactivation of phenylpropanoids coincided with the upregulation of genes that belong in a secondary response mechanism, supporting an elegant reprogramming of the host transcriptome to establish a robust defense apparatus and suppress pathogen invasion. This high-throughput analysis reveals a dynamic reorganization of plant defense mechanisms upon bacterial infection to implement an array of barriers preventing pathogen invasion and spread.

Risk and Environmental Factors Associated with the Presence of Canine Parvovirus Type 2 in Diarrheic Dogs from Thessaly, Central Greece.

Canine parvovirus type 2 (CPV-2) primarily infects dogs, which are the main host reservoir, causing severe gastrointestinal disease associated with immunosuppression. The present study was conducted in Thessaly, Greece and aimed to identify risk and environmental factors associated with CPV-2 infection in diarrheic dogs. Fecal samples were collected from 116 dogs presenting diarrhea and were tested by polymerase chain reaction (PCR) for the presence of CPV-2 DNA. Supplementary data regarding clinical symptoms, individual features, management factors and medical history were also gathered for each animal during clinical evaluation. Sixty-eight diarrheic dogs were found to be positive for the virus DNA in their feces. Statistical analysis revealed that CPV-2 DNA was less likely to be detected in senior dogs, while working dogs, namely hounds and shepherds, had higher odds to be positive for the virus. Livestock density and land uses, specifically the categories of discontinuous urban fabric and of human population density, were identified as significant environmental parameters associated with CPV-2 infection by using Geographical Information System (GIS) together with the Ecological Niche Model (ENM). This is the first description of the environmental variables associated with the presence of CPV-2 DNA in dogs' feces in Greece.

Genome Sequencing of five Lacticaseibacillus Strains and Analysis of Type I and II Toxin-Antitoxin System Distribution.

The analysis of bacterial genomes is a potent tool to investigate the distribution of specific traits related to the ability of surviving in particular environments. Among the traits associated with the adaptation to hostile conditions, toxin-antitoxin (TA) systems have recently gained attention in lactic acid bacteria. In this work, genome sequences of Lacticaseibacillus strains of dairy origin were compared, focusing on the distribution of type I TA systems homologous to Lpt/RNAII and of the most common type II TA systems. A high number of TA systems have been identified spread in all the analyzed strains, with type I TA systems mainly located on plasmid DNA. The type II TA systems identified in these strains highlight the diversity of encoded toxins and antitoxins and their organization. This study opens future perspectives on the use of genomic data as a resource for the study of TA systems distribution and prevalence in microorganisms of industrial relevance.

Antimicrobial Resistance Genes in ESBL-Producing Escherichia coli Isolates from Animals in Greece.

The prevalence of multidrug resistant, extended spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae is increasing worldwide. The present study aimed to provide an overview of the multidrug resistance phenotype and genotype of ESBL-producing Escherichia coli (E. coli) isolates of livestock and wild bird origin in Greece. Nineteen phenotypically confirmed ESBL-producing E. coli strains isolated from fecal samples of cattle (n = 7), pigs (n = 11) and a Eurasian magpie that presented resistance to at least one class of non ß-lactam antibiotics, were selected and genotypically characterized. A DNA-microarray based assay was used, which allows the detection of various genes associated with antimicrobial resistance. All isolates harbored blaCTX-M-1/15, while blaTEM was co-detected in 13 of them. The AmpC gene blaMIR was additionally detected in one strain. Resistance genes were also reported for aminoglycosides in all 19 isolates, for quinolones in 6, for sulfonamides in 17, for trimethoprim in 14, and for macrolides in 8. The intI1 and/or tnpISEcp1 genes, associated with mobile genetic elements, were identified in all but two isolates. This report describes the first detection of multidrug resistance genes among ESBL-producing E. coli strains retrieved from feces of cattle, pigs, and a wild bird in Greece, underlining their dissemination in diverse ecosystems and emphasizing the need for a One-Health approach when addressing the issue of antimicrobial resistance.

Growth of Staphylococcus epidermidis on the Surface of Teatcups from Milking Parlours.

The growth of two Staphylococcus epidermidis isolates (one biofilm-forming and one not) on teatcups for cattle (made of rubber) or sheep (made of silicone) were assessed in nine multiplicates for 24 h post-smearing on the teatcup surface. Staphylococci were smeared on an area of 0.0003142 m2 on the material and their growth and expansion further on were monitored for 24 h. There were no differences in the frequency of recoveries between the two isolates (p > 0.82 for all comparisons). There were more recoveries from sheep teatcups than from cattle teatcups: 1280/1728 (74.1%) versus 942/1728 (54.5%), for both isolates (p < 0.0001). Significance was observed only 6 h to 15 h after smearing (p < 0.0001 for all comparisons). The median speed of linear dissemination of the isolates was 0.00000021 m s-1 on cattle teatcups and 0.00000033 m s-1 on sheep teatcups (p < 0.0001). The increased growth and faster expansion of staphylococci on silicone teatcups raise important points from a clinical viewpoint. The model could be used in the testing of staphylococcal growth in the material of milking parlours in various conditions.

From Proteomic Mapping to Invasion-Metastasis-Cascade Systemic Biomarkering and Targeted Drugging of Mutant BRAF-Dependent Human Cutaneous Melanomagenesis.

Melanoma is classified among the most notoriously aggressive human cancers. Despite the recent progress, due to its propensity for metastasis and resistance to therapy, novel biomarkers and oncogenic molecular drivers need to be promptly identified for metastatic melanoma. Hence, by employing nano liquid chromatography-tandem mass spectrometry deep proteomics technology, advanced bioinformatics algorithms, immunofluorescence, western blotting, wound healing protocols, molecular modeling programs, and MTT assays, we comparatively examined the respective proteomic contents of WM115 primary (n = 3955 proteins) and WM266-4 metastatic (n = 6681 proteins) melanoma cells. It proved that WM115 and WM266-4 cells have engaged hybrid epithelial-to-mesenchymal transition/mesenchymal-to-epithelial transition states, with TGF-ß controlling their motility in vitro. They are characterized by different signatures of SOX-dependent neural crest-like stemness and distinct architectures of the cytoskeleton network. Multiple signaling pathways have already been activated from the primary melanoma stage, whereas HIF1α, the major hypoxia-inducible factor, can be exclusively observed in metastatic melanoma cells. Invasion-metastasis cascade-specific sub-routines of activated Caspase-3-triggered apoptosis and LC3B-II-dependent constitutive autophagy were also unveiled. Importantly, WM115 and WM266-4 cells exhibited diverse drug response profiles, with epirubicin holding considerable promise as a beneficial drug for metastatic melanoma clinical management. It is the proteome navigation that enables systemic biomarkering and targeted drugging to open new therapeutic windows for advanced disease.

Poultry and Wild Birds as a Reservoir of CMY-2 Producing Escherichia coli: The First Large-Scale Study in Greece.

Resistance mediated by ß-lactamases is a globally spread menace. The aim of the present study was to determine the occurrence of Escherichia coli producing plasmid-encoded AmpC ß-lactamases (pAmpC) in animals. Fecal samples from chickens (n = 159), cattle (n = 104), pigs (n = 214), and various wild bird species (n = 168), collected from different Greek regions during 2018-2020, were screened for the presence of pAmpC-encoding genes. Thirteen E. coli displaying resistance to third-generation cephalosporins and a positive AmpC confirmation test were detected. blaCMY-2 was the sole pAmpC gene identified in 12 chickens' and 1 wild bird (Eurasian magpie) isolates and was in all cases linked to an upstream ISEcp1-like element. The isolates were classified into five different sequence types: ST131, ST117, ST155, ST429, and ST1415. Four chickens' stains were assigned to ST131, while five chickens' strains and the one from the Eurasian magpie belonged to ST117. Seven pAmpC isolates co-harbored genes conferring resistance to tetracyclines (tetM, tetB, tetC, tetD), 3 carried sulfonamide resistance genes (sulI and sulII), and 10 displayed mutations in the quinolone resistance-determining regions of gyrA (S83L+D87N) and parC (S80I+E84V). This report provides evidence of pAmpC dissemination, describing for the first time the presence of CMY-2 in chickens and wild birds from Greece.

MLST-Based Analysis and Antimicrobial Resistance of Staphylococcus epidermidis from Cases of Sheep Mastitis in Greece.

Staphylococcus epidermidis is an important causal agent of ovine mastitis. A literature search indicated a lack of systematic studies of causal agents of the infection by using multi-locus sequence typing (MLST). The objectives were to analyse MLST-based data and evaluate the antimicrobial resistance of S. epidermidis isolates from ovine mastitis in Greece. The database included 1593 isolates from 46 countries: 1215 of human, 195 of environmental and 134 of animal origin, distributed into 949 sequence types (STs) and cumulatively with 450 alleles therein. Among mastitis isolates, bovine isolates were distributed into 36 different STs and ovine ones into 15 STs. The 33 isolates from ovine mastitis in Greece were in 15 different STs, 6 of these (ST677, ST678, ST700, ST 709, ST710, ST711) assigned for the first time; in addition, 5 alleles (65 for arcC, 59 for aroE, 56 and 57 for gtr and 48 for tpiA) were identified for the first time. The spanning tree of these isolates included 15 nodes and 14 edges (i.e., branches). Among these isolates, 19 showed resistance to antimicrobial agents (tetracycline, penicillin, fucidic adic, erythromycin, clindamycin, cefoxitin). Resistance-related genes (tetK, tetT, msrA, tetM, tetS, ermC, mecA) were detected. There was no association between STs and resistance to antimicrobial agents. Isolates with antimicrobial resistance were recovered more often from flocks where hand-milking was practised.

Experimental Study of the Potential Role of Salmonella enterica subsp. diarizonae in the Diarrhoeic Syndrome of Lambs.

The objectives of this experimental work were the evaluation of the potential role of Salmonella enterica subsp. diarizonae in diarrhoeic syndrome in lambs and the investigation of facets of the pathogenesis of the infection. In total, 12 lambs were challenged orally on the first day of life, with a S. enterica subsp. diarizonae isolate from a clinical case of diarrhoeic syndrome. Sequential blood, faecal and buccal samples were collected from lambs and faecal and milk samples were taken from their dams. Lambs were euthanised 1, 2, 4, 7, 10, 14 and 21 days after challenge. Samples were processed for recovery of the challenge organism; they were also subjected to examination by PCR for detection of the invA gene. Tissue samples from lambs were also examined as above and histopathologically. S. enterica subsp. diarizonae was recovered from faecal samples of all lambs, in total, from 45/77 samples (median duration: 2.4 days post-inoculation). It was also recovered from buccal samples (10/77) from seven lambs (median duration: 0.8 days), and from tissue samples (small intestine, abomasum, liver, gallbladder) of nine lambs. It was recovered from two consecutive milk samples from the same ewe, but not from any faecal sample from ewes. The invA gene was detected in samples from all lambs (median duration: 5.5 days in faecal and 1.3 days in buccal samples), as well as in milk samples from three ewes. Histopathological findings included abomasitis with subepithelial presence of eosinophils, lymphocytes and plasma cells, consistently observed in all lambs. In the small intestine, salient lesions initially included distension and oedema of intestinal villi, leucocytic infiltration and hyperplasia of lymphoid nodules with apparent germinal centres; this was followed at later stages by atrophy and/or degeneration of the lymphoid tissue of the intestine with marked subepithelial infiltration of lymphocytes, plasma cells and eosinophils.