Host-Diet Effect on the Metabolism of Bifidobacterium

Bifidobacterium has a diverse host range and shows several beneficial properties to the hosts. Many species should have co-evolved with their hosts, but the phylogeny of Bifidobacterium is dissimilar to that of host animals. The discrepancy could be linked to the niche-specific evolution due to hosts’ dietary carbohydrates. We investigated the relationship between bifidobacteria and their host diet using a comparative genomics approach. Since carbohydrates are the main class of nutrients for bifidobacterial growth, we examined the distribution of carbohydrate-active enzymes, in particular glycoside hydrolases (GHs) that metabolize unique oligosaccharides. When bifidobacterial species are classified by their distribution of GH genes, five groups arose according to their hosts’ feeding behavior. The distribution of GH genes was only weakly associated with the phylogeny of the host animals or with genomic features such as genome size. Thus, the hosts’ dietary pattern is the key determinant of the distribution and evolution of GH genes

In silico RFLP Analysis of 16S rRNA Genes: A Helpful Application for Distinguishing Bifidobacteria from Human and Animal Source

Bifidobacterial species are widespread in gastrointestinal tracts of mammalian and other animals; they can be found in extra body environment only after a fecal contamination or human intentional addition (as the case of probiotics). Interestingly their occurrence is strictly linked to their hosts with a clear demarcation between animal and human species. PCR-restriction fragment length polymorphism (PCR-RFLP) on the 16S rRNA gene, using Alul, and TaqI restriction enzymes, have been utilized to distinguish the animal or human source of 64 strains belonging to 13 Bifidobacterium species (Delcenserie et al. [15]). Our aim was to test this method updating an in silico restriction analysis on the available 16S rRNA gene sequences of all 55 currently described taxa of Bifidobacterium genus. Our results confirmed the reliability of this method, optimized with the use of three restriction enzymes: Alul, TaqI and MaeIII, as a fast and simple strategy to determine the origin (human or animal) of bifidobacteria. Interestingly, the bifidobacterial species recently isolated from non-human primates cluster in the group of animal source except the bifidobacterial species isolated from higher non-human primates closest to humans such as apes (chimpanzee, orangutan and gorilla) that clusters with human group. Moreover, B. minimum, B. subtile and B. mongoliense isolated only from extrabody environment of which the source is unknown clustered with animal species. The in silico RFLP-PCR confirmed its powerful ability to attribute the primary source of occurrence (human or animal) for bifidobacterial species to the human or animal habitat

Bifidobacterium mellis sp. nov., isolated from the honey stomach of the honey bee Apis mellifera

: A novel Bifidobacterium strain, Bin7NT, was isolated from the honey stomach of the honey bee Apis mellifera. Cells are Gram-positive, non-motile, non-sporulating, facultative anaerobic and fructose 6-phosphate phosphoketolase-positive. Their optimal growth is at 37 °C in anaerobiosis in MRS (De Man, Rogosa and Sharpe) added with cysteine. The honey bee microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain Bin7NT grouped with Bifidobacterium species originating from honey bees and was closely related to Bifidobacterium asteroides DSM 20089T (99.67 % similarity). However, the highest average nucleotide identity and digital DNA-DNA hybridization values of 94.88 and 60.6 %, respectively, were obtained with Bifidobacterium choladohabitans JCM 34586T. The DNA G+C content of the type strain is 60.8 mol%. The cell-wall peptidoglycan is of the A4β l-Orn-d-Asp type. The main cellular fatty acids of strain Bin7NT are C18 : 1 ω9c, C16 : 0, C18 : 1 ω7c and C18 : 0. Phenotypic characterization and genotyping based on the genome sequences clearly show that this strain is distinct from the type strains of the so far recognized Bifidobacterium species. Thus, Bifidobacterium mellis sp. nov. (Bin7NT=DSM 29108T=CCUG 66113T) is proposed as novel Bifidobacterium species

Efficient isolation on Vero.DogSLAMtag cells and full genome characterization of Dolphin Morbillivirus (DMV) by next generation sequencing

The Dolphin Morbillivirus (DMV) genome from the frst Mediterranean epidemic (1990-\u201992) is the only cetacean Morbillivirus that has been completely sequenced. Here, we report the frst application of next generation sequencing (NGS) to morbillivirus infection of aquatic mammals. A viral isolate, representative of the 2006-\u201908 Mediterranean epidemic (DMV_IZSPLV_2008), efciently grew on Vero.DogSLAMtag cells and was submitted to whole genome characterization by NGS. The fnal genome length was 15,673 nucleotides, covering 99.82% of the DMV reference genome. Comparison of DMV_IZSPLV_2008 and 1990-\u201992 DMV strain sequences revealed 157 nucleotide mutations and 47 amino acid changes. The sequence similarity was 98.7% at the full genome level. Whole-genome phylogeny suggested that the DMV strain circulating during the 2006-\u201908 epidemics emerged from the 1990-\u201992 DMV strain. Viral isolation is considered the \u201cgold standard\u201d for morbillivirus diagnostics but efcient propagation of infectious virus is difcult to achieve. The successful cell replication of this strain allowed performing NGS directly from the viral RNA, without prior PCR amplifcation. We therefore provide to the scientifc community a second DMV genome, representative of another major outbreak. Interestingly, genome comparison revealed that the neglected L gene encompasses 74% of the genetic diversity and might serve as \u201chypervariable\u201d target for strain characterization

DNA Pool Analysis-based Forgery-Detection of Dairy Products

Food integrity and food safety have received much attention in recent years due to the dramatic increasing number of food frauds. In this article we focus on the problem of dairy products traceability. In particular, we propose an automatic forgery detection system able to detect frauds in milk and cheese. We investigate the use of Short Tandem Repeats analysis data, processed by a Covariance Matrix Adaptation Evolution Strategy algorithm in order to evaluate a traceability score between the products and their producer, and to highlight possible adulterations and inconsistencies. To demonstrate the usability of the proposed heuristic algorithm in a real setup, we also present the results collected from two real Italian farms

Computer-Assisted Molecular Traceability for Dairy Farming Products

Food integrity and food safety have received much attention in recent years due to the dramatic increasing number of food frauds. In this article we analyze dairy products for which one of the crucial issues is traditional cheese traceability. In this paper we propose a computer- assisted molecular traceability system able to certify a traditional dairy product. We investigate the use of short tandem repeat analysis data processed by a Covariance Matrix Adaptation Evolution Strategy algo- rithm in order to predict the traceability between dairy products and the corresponding producer and to highlight possible adulterations and/or inconsistencies. Preliminary results collected from two farms are pre- sented in this study to show the capability of the proposed algorithm in a real setup

Gut microbiota profiles and characterization of cultivable fungal isolates in IBS patients

Studies so far conducted on irritable bowel syndrome (IBS) have been focused mainly on the role of gut bacterial dysbiosis in modulating the intestinal permeability, inflammation, and motility, with consequences on the quality of life. Limited evidences showed a potential involvement of gut fungal communities. Here, the gut bacterial and fungal microbiota of a cohort of IBS patients have been characterized and compared with that of healthy subjects (HS). The IBS microbial community structure differed significantly compared to HS. In particular, we observed an enrichment of bacterial taxa involved in gut inflammation, such as Enterobacteriaceae, Streptococcus, Fusobacteria, Gemella, and Rothia, as well as depletion of health-promoting bacterial genera, such as Roseburia and Faecalibacterium. Gut microbial profiles in IBS patients differed also in accordance with constipation. Sequence analysis of the gut mycobiota showed enrichment of Saccharomycetes in IBS. Culturomics analysis of fungal isolates from feces showed enrichment of Candida spp. displaying from IBS a clonal expansion and a distinct genotypic profiles and different phenotypical features when compared to HS of Candida albicans isolates. Alongside the well-characterized gut bacterial dysbiosis in IBS, this study shed light on a yet poorly explored fungal component of the intestinal ecosystem, the gut mycobiota. Our results showed a differential fungal community in IBS compared to HS, suggesting potential for new insights on the involvement of the gut mycobiota in IBS. KEY POINTS: Comparison of gut microbiota and mycobiota between IBS and healthy subjects Investigation of cultivable fungi in IBS and healthy subjects Candida albicans isolates result more virulent in IBS subjects compared to healthy subjects

Screening eye diseases in babies: an Italian experience on 5000 healthy, consecutive newborns

Visual performance of eyes with congenital pathologies is conditioned by an early diagnosis. Families having problems in accessing health services risk to delay or miss both an early diagnosis and the approach to disease treatment and amblyopia (lazy eye) prevention. In our hospital, all full-term, healthy newborns are thoroughly examined by an ophthalmologist in the maternal ward, 1 to 3 days after birth. Among the first 5,000 newborns examined, a high incidence of congenital pathologies compared to international literature was reported, with differences between Caucasians and non-Caucasians. Performing an early in-hospital thorough eye examination in all newborns as a screening would be an effective way to miss none and to start an effective pathway of disease treatment in due time.