Antimicrobial Susceptibility of Enterococcal Species Isolated from Italian Dogs

Monitoring planes of the occurrence of antimicrobial resistance among bacteria isolated from both animals and humans should be considered essential and strategic for preserving not only human health but also animal welfare (well-being). Moreover, the use of antimicrobial in companion animals (pets) received little attention and is not currently regulated in comparison with what happens in livestock; for this reason, the prevalence of antibiotic resistance in 165 different Enterococcus strains isolated from dogs (subjected to previous antibiotic treatment(s) or not) was determined. For each strain, the minimum inhibitory concentration (MIC) against 9 different antibiotics was assessed. While all isolated strains were susceptible to vancomycin, high resistance frequency toward erythromycin, rifampicin, enrofloxacin, and tetracycline was detected. Enterococcus faecium strains isolated from the previously treated dogs demonstrated more resistance to tetracycline compared to the control ones. Although canine enterococci showed a high degree of antibiotic resistance, they were susceptible to vancomycin, and for this reason, the hypothetical contamination of vancomycin-resistant enterococcal strains in dogs is still considered to be minimal in Italy

A preliminary molecular typing by PCR assays of Clostridium perfringens and Clostridium difficile isolates from dogs

Clostridium perfringens and C. difficile have been associated with acute and chronic large and small bowel diarrhoea, and acute haemorrhagic diarrhoeal syndrome in dogs. The objective of this study was to investigate by toxin gene pro- file and PCR-ribotyping the molecular characteristics of 14 C. perfringens and 10 C. difficile isolates from 95 canine faeces (n = 36, diarrhoeic and n = 59, non-diarrhoeic). Concerning C. perfringens, 13 strains (92.9%) were type A, of which 3 (23.1%) also possessed the beta 2 toxin (CPB2)-encoding gene. One isolate (7.1%) was type D and possessed CPB2 gene. On the whole, 4 of the 14 strains (28.6%) tested cpb2-positive. Six C. difficile isolates (60.0%) demon- strated tcdA+/tcdB+ and cdtA+/cdtB+ genotype and tested positive for, in vitro, toxin production by EIA. Eight distinct ribotypes were observed. In conclusion, the PCR assays may provide useful and reliable tools for C. perfringens and C. difficile molecular typing in routine veterinary diagnostics

Catching a glimpse of the bacterial gut community of companion animals: a canine and feline perspective

Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and welfare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community. The application of high-throughput sequencing techniques to canine and feline faecal samples revealed similarities in their bacterial composition, with Fusobacteria, Firmicutes and Bacteroidetes as the most prevalent and abundant phyla, followed by Proteobacteria and Actinobacteria. Although key bacterial members were consistently present in their gut microbiota, the taxonomic composition and the metabolic repertoire of the intestinal microbial population may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis. The current review aims to provide a comprehensive overview of the multitude of factors which play a role in the modulation of the canine and feline gut microbiota and that of their human owners with whom they share the same environment

Bifidobacterial dialogue with its human host and consequent modulation of the immune system

Since bifidobacteria are among the pioneering colonizers of the human infant gut, their interaction with their host is believed to start soon following birth. Several members of the Bifidobacterium genus are purported to exert various health-promoting effects at local and systemic levels, e.g., limiting pathogen colonization/invasion, influencing gut homeostasis, and influencing the immune system through changes in innate and/or adaptive immune responses. This has promoted extensive research efforts to shed light on the precise mechanisms by which bifidobacteria are able to stimulate and interact with the host immune system. These studies uncovered a variety of secreted or surface-associated molecules that act as essential mediators for the establishment of a bifidobacteria-host immune system dialogue, and that allow interactions with mucosa-associated immune cells. Additionally, the by-products generated from bifidobacterial carbohydrate metabolism act as vectors that directly and indirectly trigger the host immune response, the latter by stimulating growth of other commensal microorganisms such as propionate- or butyrate-producing bacteria. This review is aimed to provide a comprehensive overview on the wide variety of strategies employed by bifidobacteria to engage with the host immune system

CONTROLLO DELLE INFEZIONI DA SALMONELLA NEL SUINO: STRATEGIE VACCINALI CONTROLLING SALMONELLA INFECTIONS IN PIGS: VACCINATION PROTOCOLS

Abstract first results. Salmonella sp. is responsible of human infections due to consumption of contaminated pork products. Carrier pigs introduce bacteria in the slaughter process. Italian situation is characterized by a high percentage of infected farms, and vaccination could have a decisive role in controlling infection. Unfortunately, none vaccine, licensed for swine, is available in Italy. The aim of our work is to describe data related to eficacy and safety of an attenuated S.Typhimurium vaccine, tested in experimental conditions, and an inactivated autogenous vaccine, tested in ield conditions. Attenuated strain is safe and protective, limiting fecal spread and organs colonization by virulent S.Typhimurium and it is also effective when intramuscularly administered or challenge is performed with S.Choleraesuis. Inactivated autogenous vaccine was administered in pregnant sows and their piglets of two farms. The results of this trial conirmed that sows vaccination, therefore antibody transfer with colostrum, is more protective than direct piglets vaccination

Three-Dimensional (3D) Printed Silver Nanoparticles/Alginate/Nanocrystalline Cellulose Hydrogels: Study of the Antimicrobial and Cytotoxicity Efficacy

Here, a formulation of silver nanoparticles (AgNPs) and two natural polymers such as alginate (ALG) and nanocrystalline cellulose (CNC) was developed for the 3D printing of scaffolds with large surface area, improved mechanical resistance and sustained capabilities to promote antimicrobial and cytotoxic effects. Mechanical resistance, water content, morphological characterization and silver distribution of the scaffolds were provided. As for applications, a comparable antimicrobial potency against S. aureus and P. aeruginosa was demonstrated by in vitro tests as function of the AgNP concentration in the scaffold (Minimal Inhibitory Concentration value: 10 mg/mL). By reusing the 3D system the antimicrobial efficacy was demonstrated over at least three applications. The cytotoxicity effects caused by administration of AgNPs to hepatocellular carcinoma (HepG2) cell culture through ALG and ALG/CNC scaffold were discussed as a function of time and dose. Finally, the liquid chromatography-mass spectrometry (LC-MS) technique was used for targeted analysis of pro-apoptotic initiation and executioner caspases, anti-apoptotic and proliferative proteins and the hepatocyte growth factor, and provided insights about molecular mechanisms involved in cell death induction

Isolation of novel gut bifidobacteria using a combination of metagenomic and cultivation approaches

Whole metagenome shotgun (WMGS) sequencing is a method that provides insights into the genomic composition and arrangement of complex microbial consortia. Here, we report how WMGS coupled with a cultivation approach allows the isolation of novel bifidobacteria from animal fecal samples. A combination of in silico analyses based on nucleotide and protein sequences facilitate the identification of genetic material belonging to putative novel species. Consequently, the prediction of metabolic properties by in silico analyses permits the identification of specific substrates that are then employed to isolate these species through a cultivation method

Prophages of the genus Bifidobacterium as modulating agents of the infant gut microbiota

Phage predation is one of the key forces that shape genetic diversity in bacterial genomes. Phages are also believed to act as modulators of the microbiota composition and, consequently, as agents that drive bacterial speciation in complex bacterial communities. Very little is known about the occurrence and genetic variability of (pro)phages within the genus, a dominant bacterial group of the human infant microbiota. Here, we performed cataloguing of the predicted prophage sequences from the genomes of all currently recognized bifidobacterial type strains. We analysed their genetic diversity and deduced their evolutionary development, thereby highlighting an intriguing origin. Furthermore, we assessed infant gut microbiomes for the presence of (pro)phage sequences and found compelling evidence that these viral elements influence the composition of bifidobacterial communities in the infant gut microbiot

Phylogenetic classification of six novel species belonging to the genus Bifidobacterium comprising Bifidobacterium anseris sp. nov., Bifidobacterium criceti sp. nov., Bifidobacterium imperatoris sp. nov., Bifidobacterium italicum sp. nov., Bifidobacterium margollesii sp. nov. and Bifidobacterium parmae sp. nov

Six Bifidobacterium strains, i.e., Goo31D, Ham19E, Rab10A, Tam1G, Uis4E and Uis1B, were isolated from domestic goose (Anser domesticus), European hamster (Cricetus cricetus), European rabbit (Oryctolagus cuniculus), emperor tamarin (Saguinus imperator) and pygmy marmoset (Callithrix pygmaea), respectively. Cells are Gram-positive, non-motile, non-sporulating, facultative anaerobic and fructose 6-phosphate phosphoketolase-positive. Phylogenetic analyses based on 16S rRNA and ITS sequences, multilocus sequences (including hsp60, rpoB, dnaJ, dnaG and clpC genes) and the core genome revealed that bifidobacterial strains Goo31D, Ham19E, Rab10A, Tam1G, Uis4E and Uis1B exhibit close phylogenetic relatedness to Bifidobacterium choerinum LMG 10510, Bifidobacterium hapali DSM 100202, Bifidobacterium saguini DSM 23967 and Bifidobacterium stellenboschense DSM 23968. Further genotyping based on the genome sequence of the isolated strains combined with phenotypic analyses, clearly show that these strains are distinct from each of the type strains of the so far recognized Bifidobacterium species. Thus, Bifidobacterium anseris sp. nov. (Goo31D = LMG 30189T = CCUG 70960T), Bifidobacterium criceti sp. nov. (Ham19E = LMG 30188T = CCUG 70962T), Bifidobacterium imperatoris sp. nov. (Tam1G = LMG 30297T = CCUG 70961T), Bifidobacterium italicum sp. nov. (Rab10A = LMG 30187T = CCUG 70963T), Bifidobacterium margollesii sp. nov. (Uis1B = LMG 30296T = CCUG 70959T) and Bifidobacterium parmae sp. nov. (Uis4E = LMG 30295T = CCUG 70964T) are proposed as novel Bifidobacterium species