Dogs Leaving the ICU Carry a Very Large Multi-Drug Resistant Enterococcal Population with Capacity for Biofilm Formation and Horizontal Gene Transfer

The enterococcal community from feces of seven dogs treated with antibiotics for 2–9 days in the veterinary intensive care unit (ICU) was characterized. Both, culture-based approach and culture-independent 16S rDNA amplicon 454 pyrosequencing, revealed an abnormally large enterococcal community: 1.4±0.8×108 CFU gram−1 of feces and 48.9±11.5% of the total 16,228 sequences, respectively. The diversity of the overall microbial community was very low which likely reflects a high selective antibiotic pressure. The enterococcal diversity based on 210 isolates was also low as represented by Enterococcus faecium (54.6%) and Enterococcus faecalis (45.4%). E. faecium was frequently resistant to enrofloxacin (97.3%), ampicillin (96.5%), tetracycline (84.1%), doxycycline (60.2%), erythromycin (53.1%), gentamicin (48.7%), streptomycin (42.5%), and nitrofurantoin (26.5%). In E. faecalis, resistance was common to tetracycline (59.6%), erythromycin (56.4%), doxycycline (53.2%), and enrofloxacin (31.9%). No resistance was detected to vancomycin, tigecycline, linezolid, and quinupristin/dalfopristin in either species. Many isolates carried virulence traits including gelatinase, aggregation substance, cytolysin, and enterococcal surface protein. All E. faecalis strains were biofilm formers in vitro and this phenotype correlated with the presence of gelE and/or esp. In vitro intra-species conjugation assays demonstrated that E. faecium were capable of transferring tetracycline, doxycycline, streptomycin, gentamicin, and erythromycin resistance traits to human clinical strains. Multi-locus variable number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) of E. faecium strains showed very low genotypic diversity. Interestingly, three E. faecium clones were shared among four dogs suggesting their nosocomial origin. Furthermore, multi-locus sequence typing (MLST) of nine representative MLVA types revealed that six sequence types (STs) originating from five dogs were identical or closely related to STs of human clinical isolates and isolates from hospital outbreaks. It is recommended to restrict close physical contact between pets released from the ICU and their owners to avoid potential health risks

Molecular toxinotyping of Clostridium perfringens and Clostridium difficile cattle isolates by PCR assays

Clostridium perfringens and C. difficile are common causes of enteritis and enterotoxaemia in humans and domestic and wild animals. The purpose of this study was to investigate the enterotoxigenity of Clostridium cattle isolates by PCR assays. One hundred and nineteen bovine (faecal and intestine) samples were analyzed by culture assay. All C. perfringens isolates were screened for the characterization of the toxinotype. C. difficile strains were PCR-tested for the presence of tcdA/tcdB and cdtA/cdtB genes. Overall, 53 bovine samples tested positive: 37 for C. perfringens and 16 for C. difficile. ln two C. perfringens-positive diarrhoeic samples, C. difficile was also isolated. All C. perfringens isolates were type A; C. difficile strains resulted tcdA/tcdB and cdtA/cdtB-negative. Understanding the diversity of toxigenic strains may lead to a greater understanding of the pathogenesis in cattle and aid in the development of effective intervention methods for controlling clostridial disease outbreak

Microbiologia e Immunologia Veterinaria, Terza edizione

All' inizio del terzo millennio, lo scenario dell scienze biomediche \ue8 stato caratterizzato da eventi che coinvolgono prioritariamente la microbiologia e l' immunologia. Ne sono un esempio epidemie quali la SARS, l' influenza aviaria e umana, la Blue Tongue, le malattie da prioni ( BSE e la malattia di Creutzfeldt - Jakob ) e, non ultimo, il bioterrorismo con l' antrace. Il medico veterinario ( e ancor prima lo studente ) necessita pertanto di nozioni e informazioni che gli consentano di affrontare, nel lavoro quotidiano, sia le " emergenze sanitarie ", sia le " nuove patologie infettive ".Il volume \ue8 particolarmente adatto sia a coloro che si dedicano a discipline medico - biologiche, siano essi studenti universitari in Medicina Veterinaria e in Scienze delle Produzioni Animali o laureati iscritti a corsi di specializzazione, sia a medici veterinari, liberi professionisti od operanti presso strutture pubbliche che intendono rimanere aggiornati su discipline in cos\uec rapida evoluzione

Unveiling bifidobacterial biogeography across the mammalian branch of the tree of life

Internally transcribed spacer (ITS) rRNA profiling is a novel tool for detailed analysis of microbial populations at low taxonomic ranks. Here we exploited this approach to explore species-level biogeography of the Bifidobacterium genus across 291 adult mammals. These include humans and 13 other primates, domesticated animals, such as dogs, cats, cows, sheep, goats, horses and pigs, and 46 additional species. The collected profiles revealed the presence of 89 putative novel bifidobacterial taxa in addition to 45 previously described species. Remarkably, in contrast to what is currently known for many gut commensals, we did not observe host-specialization among bifidobacterial species but rather their widespread distribution across mammals. Moreover, ITS rRNA profiling of wild relatives of domesticated dogs, rabbits and pigs clearly indicates that domestication and close contact with humans have impacted on the composition of the fecal bifidobacterial population. These data were complemented by analysis of bifidobacterial communities in milk of eight mammalian families, showing that bifidobacteria represent prototypical early gut microbiota members which are inherited by newborns from their lactating mother. Thus this study highlights the role of bifidobacteria as pioneering gut colonizers of a wide range of mammals