Mortality in kittens is associated with a shift in ileum mucosa-associated enterococci from Enterococcus hirae to biofilm-forming Enterococcus faecalis and adherent Escherichia coli. J Clin Microbiol. 2013;51:3567-3578. [PMID: 23966487 DOI: 10.1128/jcm.00481-13]

Gut Probiotics and Health of Dogs and Cats: Benefits, Applications, and Underlying Mechanisms

Pets (mostly domestic dogs and cats) play an important role in the daily lives of humans and their health has attracted growing attention from pet owners. The intestinal microbiota, a complex microbial community with barrier-protective, nutritional, metabolic, and immunological functions, is integral to host health. Dysbiosis has been related to a variety of diseases in humans and animals. Probiotics have been used in functional foods and dietary supplements to modulate intestinal microbiota and promote host health, which has been introduced in pet dogs and cats in recent years. Various canine- and feline-derived probiotic strains have been isolated and characterized. The administration of probiotics has shown positive effects on the gut health and can alleviate some intestinal diseases and disorders in dogs and cats, although the underlying mechanisms are largely unresolved. In this review, we summarize the current knowledge on the benefits of probiotics and discuss their possible mechanisms in dogs and cats in order to provide new insights for the further development and application of probiotics in pets.

Two cases of bloodstream infections associated with opportunistic bacterial species (Enterococcus hirae and Enterobacter xiangfangensis) in companion animals

BACKGROUND

Bloodstream infections are a matter of concern in small animal veterinary practice. Few reports are avaiable, especially regarding the role of opportunistic bacteria in becoming infectious. This report aims to add to the current veterinary literature on two opportunistic bacterial species (Enterococcus hirae and Enterobacter xiangfangensis) associated with bloodstream infections in small animals admitted to the Bologna University Veterinary Hospital.

CASE PRESENTATION

In the first case, a 15-year-old, immunocompromised, cardiopathic dog was admitted to the hospital for anorexia and diarrhea. The patient had a history of previous surgery and hospitalization. After three days, hyperthermia, leukopenia and hyperlactatemia were recorded, and blood culture revealed positivity for Enterococcus hirae, identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The patient's general conditions progressively worsened, and the patient was euthanized. In the second case, a 2-year-old cat with chronic ocular herpesvirus infection and hypertrophic cardiomyopathy was admitted to the hospital for anorexia and hyperthermia. The cat was hospitalized one week before and received antimicrobial treatment for urinary tract infection by Staphylococcus felis. Hypokalemia and lymphopenia were also diagnosed. The patient progressively improved and was discharged after three days. On the same day, blood culture taken at admission revealed positivity for Enterobacter xiangfangensis, identified using MALDI-TOF MS. After five days, the patient returned with neurological symptoms, hypothermia and bradycardia, and was euthanized.

CONCLUSIONS

In small animal veterinary practice, the impact of opportunistic bacterial agents (such as E.hirae and E.xiangfangensis) on bloodstream infections remains unclear. As in human medicine, they can be contracted in every healthcare setting and considered hospital-acquired infections. In this report, we highlighted the threat they pose especially in patients with multiple risk factors. Rapid and accurate diagnostic tools (such as MALDI-TOF MS) could be particularly important for reducing the severity of the infections.

Gallbladder microbiota in healthy dogs and dogs with mucocele formation

To date studies have not investigated the culture-independent microbiome of bile from dogs, a species where aseptic collection of bile under ultrasound guidance is somewhat routine. Despite frequent collection of bile for culture-based diagnosis of bacterial cholecystitis, it is unknown whether bile from healthy dogs harbors uncultivable bacteria or a core microbiota. The answer to this question is critical to understanding the pathogenesis of biliary infection and as a baseline to exploration of other biliary diseases in dogs where uncultivable bacteria could play a pathogenic role. A pressing example of such a disease would be gallbladder mucocele formation in dogs. This prevalent and deadly condition is characterized by excessive secretion of abnormal mucus by the gallbladder epithelium that can eventually lead to rupture of the gallbladder or obstruction of bile flow. The cause of mucocele formation is unknown as is whether uncultivable, and therefore unrecognized, bacteria play any systematic role in pathogenesis. In this study we applied next-generation 16S rRNA gene sequencing to identify the culture-negative bacterial community of gallbladder bile from healthy dogs and gallbladder mucus from dogs with mucocele formation. Integral to our study was the use of 2 separate DNA isolations on each sample using different extraction methods and sequencing of negative control samples enabling recognition and curation of contaminating sequences. Microbiota findings were validated by simultaneous culture-based identification, cytological examination of bile, and fluorescence in-situ hybridization (FISH) performed on gallbladder mucosa. Using culture-dependent, cytological, FISH, and 16S rRNA sequencing approaches, results of our study do not support existence of a core microbiome in the bile of healthy dogs or gallbladder mucus from dogs with mucocele formation. Our findings further document how contaminating sequences can significantly contribute to the results of sequencing analysis when performed on samples with low bacterial biomass.

Randomized placebo-controlled trial of feline-origin Enterococcus hirae probiotic effects on preventative health and fecal microbiota composition of fostered shelter kittens

INTRODUCTION

Diarrhea is the second most common cause of mortality in shelter kittens. Studies examining prevention strategies in this population are lacking. Probiotics are of particular interest but studies in cats are largely limited to healthy adults or those with induced disease. Only one study in domestic cats describes the use of host-derived bacteria as a probiotic. We previously identified Enterococcus hirae as a dominant species colonizing the small intestinal mucosa in healthy shelter kittens. Oral administration of a probiotic formulation of kitten-origin E. hirae (strain 1002-2) mitigated the increase in intestinal permeability and fecal water loss resulting from experimental enteropathogenic E. coli infection in purpose-bred kittens. Based on these findings, we hypothesized that administration of kitten-origin E. hirae to weaned fostered shelter kittens could provide a measurable preventative health benefit.

METHODS

We conducted a randomized, placebo-controlled, blinded clinical trial to determine the impact of a freeze-dried E. hirae probiotic on body weight gain, incidence of diarrhea, carriage of potential diarrheal pathogens, and composition of the intestinal microbiota in weaned fostered shelter kittens.

RESULTS

One-hundred thirty kittens completed the study. Fifty-eight kittens received the probiotic and 72 received the placebo. There were no significant differences in age, weight upon initiation of the study, number of days in the study, average daily gain in body weight, or weight at completion of the study. Kittens treated with E. hirae were 3.4 times less likely to develop diarrhea compared to kittens treated with placebo (odds ratio = 0.294, 95% CI 0.109-0.792, p = 0.022). A significant impact of E. hirae was not observed on the presence or abundance of 30 different bacterial, viral, protozoal, fungal, algal, and parasitic agents in feces examined by qPCR. With exception to a decrease in Megamonas, administration of the E. hirae probiotic did not alter the predominant bacterial phyla present in feces based on 16S rRNA gene amplicon sequencing.

DISCUSSION

Decreased incidence of diarrhea associated with preventative administration of E. hirae to foster kittens supports a rationale for use of E. hirae for disease prevention in this young population at high risk for intestinal disease though additional studies are warranted.

Feline neonatology: From birth to commencement of weaning - what to know for successful management

PRACTICAL RELEVANCE

Despite considerable interest in the field of companion animal reproduction, feline neonatology remains largely unstudied. This contrasts with the need for a more professional veterinary approach to newborn kittens and feline husbandry, across the pet, breeding cattery and rescue shelter settings, to reduce kitten mortality.

GLOBAL IMPORTANCE

Feline neonatology has relevance for veterinarians around the world as cats are continuing to become established as popular companion animals.

CLINICAL CHALLENGES

Perinatal mortality in cats is remarkably high. Therefore, adequate neonatal evaluation and assistance at birth, careful monitoring of kittens in the vulnerable period until weaning begins, assessment of maternal factors and well-informed management of orphans are crucial in helping to reduce kitten losses.

AIM

This review aims to deepen the basic knowledge of the veterinary clinical team regarding the characteristics of feline newborns under normal conditions at birth through to the commencement of weaning. Much of the information is also relevant to breeders and rescue/shelter caregivers.

EVIDENCE BASE

In compiling the present review, the authors have drawn on specific feline research data, where available, complemented by data extrapolated from scientific publications on newborn dogs, and also their own and their colleagues' professional clinical experience.

Pre-mortem risk factors for mortality in kittens less than 8 weeks old at a dedicated kitten nursery

OBJECTIVES

Kittens have unique requirements for care in a shelter setting given their higher susceptibility to infectious disease and socialization needs. Significant time and resources are necessary to care for this vulnerable population and dedicated kitten nurseries are one way to meet the requirements of kittens too young for neutering and rehoming. However, young kittens remain at a higher risk of dying relative to adult cats, even in specialized settings. Efforts to investigate kitten mortality have focused on post-mortem findings and little is known about pre-mortem clinical signs that may be associated with death. The purpose of this study was to elucidate predictors of mortality in underage kittens.

METHODS

The medical records of kittens aged <8 weeks reared in a kitten nursery in New York City during 2017 were examined. The data collected included signalment (estimated age and weight at intake, sex), physical findings (body condition score [BCS]), clinical signs (weight loss, anorexia, diarrhea, upper respiratory tract infection [URI]), diagnoses (panleukopenia, trauma), how early in the feline breeding season the kitten entered (April-November), and whether the kitten had died or was euthanized. The data were analyzed using Cox proportional hazard modeling with 1353 kittens to identify factors associated with any death or euthanasia.

RESULTS

Elevated risk of dying was found for kittens in the lightest weight group (13 times greater), diagnosed with panleukopenia (13 times greater), exhibiting weight loss (>9 times greater), diagnosed with URI (almost four times greater), exhibiting anorexia (three times greater), identified with a low BCS at intake (two times greater) and experiencing diarrhea (almost two times greater).

CONCLUSIONS AND RELEVANCE

These findings identify clinical signs and diagnoses that can serve as prognostic indicators for underage kitten survival in a shelter/rescue setting and can aid in enhancing protocols for monitoring, intervention and euthanasia decision-making.

Developmental intestinal microbiome alterations in canine fading puppy syndrome: a prospective observational study

Fading puppy syndrome (FPS) is a fatal condition in neonatal dogs. Intestinal microbial alterations, although never investigated, may be involved in its pathophysiology. The study examined the occurrence of FPS and its associations with dam, puppy, and husbandry characteristics, compared the intestinal microbial diversity of healthy puppies and those with FPS, and examined whether intestinal microbiomes are predictive of FPS. Day 1 and 8 post-partum (PP) rectal swabs were collected from healthy puppies and puppies which later developed FPS. Microbial compositional structure, including alpha and beta diversities and relative abundance of specific taxa were compared between groups, and microbial data was applied to a machine-learning model to assess the predictive performance of microbial indices of FPS or death. FPS occurred in 22/165 puppies (13%), with a 100% mortality rate. FPS was associated (P < 0.001) with decreased Day 1 PP puppy activity. Day 1 (P = 0.003) and 8 (P = 0.005) PP rectal beta diversities were different in puppies with FPS vs healthy ones. Increased Proteobacteria/Firmicutes ratio, increased relative abundance of Pasteurellaceae, and decreased relative abundance of Clostridia and Enterococcus were associated with FPS. A machine-learning model showed that Day 1 PP rectal microbiome composition accurately predicted FPS-related death. We found that specific rectal microbial phenotypes are associated with FPS, reflecting the significant role of microbiome alterations in this phenomenon. These findings may serve as useful microbial indices for early diagnosis of puppies at risk of FPS and may provide specific therapeutic targets.

Comparison of Enterococcus faecalis Biofilm Removal Efficiency among Bacteriophage PBEF129, Its Endolysin, and Cefotaxime

Enterococcus faecalis is a Gram-positive pathogen which colonizes human intestinal surfaces, forming biofilms, and demonstrates a high resistance to many antibiotics. Especially, antibiotics are less effective for eradicating biofilms and better alternatives are needed. In this study, we have isolated and characterized a bacteriophage, PBEF129, infecting E. faecalis. PBEF129 infected a variety of strains of E. faecalis, including those exhibiting antibiotic resistance. Its genome is a linear double-stranded DNA, 144,230 base pairs in length. Its GC content is 35.9%. The closest genomic DNA sequence was found in Enterococcus phage vB_EfaM_Ef2.3, with a sequence identity of 99.06% over 95% query coverage. Furthermore, 75 open reading frames (ORFs) were functionally annotated and five tRNA-encoding genes were found. ORF 6 was annotated as a phage endolysin having an L-acetylmuramoyl-l-alanine amidase activity. We purified the enzyme as a recombinant protein and confirmed its enzymatic activity. The endolysin’s host range was observed to be wider than its parent phage PBEF129. When applied to bacterial biofilm on the surface of in vitro cultured human intestinal cells, it demonstrated a removal efficacy of the same degree as cefotaxime, but much lower than its parent bacteriophage.

Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens

Typical enteropathogenic Escherichia coli (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death. The purposes of this study were to (i) determine the genomic similarity between kitten aEPEC and human aEPEC isolates and (ii) identify genotypic or phenotypic traits associated with virulence in kitten aEPEC. We observed no differences between kitten and human aEPEC in core genome content or gene cluster sequence identities, and no distinguishing genomic content was observed between aEPEC isolates from kittens with nonclinical colonization (NC) versus those with lethal infection (LI). Variation in adherence patterns and ability to aggregate actin in cultured cells mirrored descriptions of human aEPEC. The aEPEC isolated from kittens with LI were significantly more motile than isolates from kittens with NC. Kittens may serve as a reservoir for aEPEC that is indistinguishable from human aEPEC isolates and may provide a needed comparative animal model for the study of aEPEC pathogenesis. Motility seems to be an important factor in pathogenesis of LI associated with aEPEC in kittens.

A One Health Perspective for Defining and Deciphering Escherichia coli Pathogenic Potential in Multiple Hosts

E. coli is one of the most common species of bacteria colonizing humans and animals. The singularity of E. coli 's genus and species underestimates its multifaceted nature, which is represented by different strains, each with different combinations of distinct virulence factors. In fact, several E. coli pathotypes, or hybrid strains, may be associated with both subclinical infection and a range of clinical conditions, including enteric, urinary, and systemic infections. E. coli may also express DNA-damaging toxins that could impact cancer development. This review summarizes the different E. coli pathotypes in the context of their history, hosts, clinical signs, epidemiology, and control. The pathotypic characterization of E. coli in the context of disease in different animals, including humans, provides comparative and One Health perspectives that will guide future clinical and research investigations of E. coli infections.

Impact of Changes in Gastrointestinal Microbiota in Canine and Feline Digestive Diseases

The intestinal microbiome is an important immune and metabolic organ in health and disease. Recent molecular and metabolomic approaches have provided a better characterization of different types of dysbiosis, including mucosa-adherent bacteria and functional changes in the microbiome. This article summarizes recent advances in assessment of dysbiosis, the importance of the bile acid-converting Clostridium hiranonis as an important beneficial bacterium in the canine gut, and different therapeutic approaches to dysbiosis.

Past, Present, and Future of Gastrointestinal Microbiota Research in Cats

The relationship between microbial community and host has profound effects on the health of animals. A balanced gastrointestinal (GI) microbial population provides nutritional and metabolic benefits to its host, regulates the immune system and various signaling molecules, protects the intestine from pathogen invasion, and promotes a healthy intestinal structure and an optimal intestinal function. With the fast development of next-generation sequencing, molecular techniques have become standard tools for microbiota research, having been used to demonstrate the complex intestinal ecosystem. Similarly to other mammals, the vast majority of GI microbiota in cats (over 99%) is composed of the predominant bacterial phyla Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. Many nutritional and clinical studies have shown that cats' microbiota can be affected by several different factors including body condition, age, diet, and inflammatory diseases. All these factors have different size effects, and some of these may be very minor, and it is currently unknown how important these are. Further research is needed to determine the functional variations in the microbiome in disease states and in response to environmental and/or dietary modulations. Additionally, further studies are also needed to explain the intricate relationship between GI microbiota and the genetics and immunity of its host. This review summarizes past and present knowledge of the feline GI microbiota and looks into the future possibilities and challenges of the field.

Antimicrobial Susceptibilities and Phylogenetic Analyses of Enterococcus hirae Isolated from Broilers with Valvular Endocarditis

Enterococcus hirae is a zoonotic Enterococcus species that causes opportunistic infections in both humans and animals and can be transmitted by contact with animals or through contaminated food. The aim of this study was to investigate the importance of E. hirae in broilers with endocarditis, as well as the antimicrobial resistance patterns and genetic relatedness of the isolates. A total of 477 three- to five-week-old broilers were studied during five fattening periods on a farm with mortality due to endocarditis. Endocarditis was observed in 27 chickens (5.66%), and samples were taken for pathological, microbiological, and molecular studies. Lesions were mainly found in the right atrioventricular valve and corresponded with a fibrinous endocarditis. Enterococcus hirae was identified in all cases. Pulsed-field gel electrophoresis results showed clonality among some isolates, with one pulsotype harboring 11 isolates that were found throughout the study. Most of the isolates showed multi-drug-resistant phenotypes. These results confirm that E. hirae is a significant cause of endocarditis in broilers, and suggest that broilers may be important carriers of antimicrobial-resistant E. hirae that might enter into the food chain.

Interventions and observations associated with survival of orphaned shelter kittens undergoing treatment for diarrhea

OBJECTIVES

The objective of this study was to identify significant associations between treatment interventions and survival of orphaned shelter kittens with diarrhea.

METHODS

Orphaned kittens admitted to a large open-intake municipal animal shelter and entering a volunteer foster care provider network between April 2016 and July 2017 were studied. Individual orphaned kittens for which the care provider sought examination by shelter veterinarians because of clinical signs of diarrhea were included. Treatments administered were recorded and their association with kitten survival to adoption or transfer to a rescue partner was statistically examined.

RESULTS

A total of 1718 orphaned kittens were fostered, among which 220 kittens (12.8%) from 118 different litters were presented for evaluation of diarrhea. A total of 172 (78.2%) kittens underwent treatment for their diarrhea, among which 153 (89.0%) survived to adoption or transfer to a rescue partner and 19 (11.0%) died or were humanely euthanized. Kittens with diarrhea that were ⩾4 weeks of age were 24.8 times more likely to survive (95% confidence interval [CI] 6.8-89.8; P <0.0001). While controlling for age, kittens that received a vitamin and mineral supplement were 12.8 times more likely to survive (95% CI 3.1-52.5; P = 0.0004) than kittens with diarrhea that did not receive the supplement. Treatment with subcutaneous fluids, penicillin G, tube feeding, a probiotic containing Enterococcus faecium SF68, ponazuril or metronidazole did not statistically significantly increase the survival of kittens with diarrhea.

CONCLUSIONS AND RELEVANCE

Age ⩾4 weeks and treatment of diarrhea with a vitamin and mineral supplement favorably improves survival of orphaned kittens to adoption. Application of these findings are likely to improve the health and welfare of this population and contribute to a refinement in use of shelter resources.

The effect of enterococci on feline Tritrichomonas foetus infection in vitro

Tritrichomonas foetus is a common cause of large bowel diarrhea in cats. Probiotics have been suggested to be effective for many intestinal pathogens; however, there are a lack of studies evaluating the effect of probiotics in T. foetus infection. In vitro studies were performed to evaluate the effect of a probiotic containing Enterococcus faecium (Efm) SF68 and a novel probiotic, Enterococcus hirae, on the inhibition of T. foetus growth, adhesion to, and cytotoxicity towards the intestinal epithelium. The effect of enterococci on T. foetus proliferation during co-culture was evaluated throughout log phase T. foetus growth. The previously validated in vitro co-culture model system using porcine intestinal epithelial cells (IPEC-J2) was used to evaluate the effect of enterococci on T. foetus adhesion and cytotoxicity towards intestinal epithelial cells. Cytotoxicity was assessed using fluorescent microscopy and spectrophotometry. Interactions of T. foetus, enterococci, and intestinal epithelial cells were assessed using scanning electron microscopy and immunofluorescence assays (IFA). Enterococcus-induced inhibition of T. foetus growth was demonstrated at concentrations as low as 10⁴ enterococci colony forming units (CFU)/mL and was dependent, in part, on environmental pH and the presence of viable enterococci organisms. T. foetus adhesion, including with a ronidazole-resistant strain, was reduced with pretreatment of intestinal epithelial cells with enterococci but was not significantly affected when enterococci were introduced simultaneously or following T. foetus infection. Compared to Efm, E. hirae more effectively decreased T. foetus adhesion, suggesting its superior potential as a novel probiotic for T. foetus infection. There was no effect of enterococci treatment on T. foetus-induced intestinal epithelial cell cytotoxicity. Our results support further study into the investigation of a possible benefit of enterococci-containing probiotic treatment for prevention of T. foetus infection in at-risk uninfected cats.

Enterococci: Between Emerging Pathogens and Potential Probiotics

Enterococci are ubiquitous microorganisms that could be found everywhere; in water, plant, soil, foods, and gastrointestinal tract of humans and animals. They were previously used as starters in food fermentation due to their biotechnological traits (enzymatic and proteolytic activities) or protective cultures in food biopreservation due to their produced antimicrobial bacteriocins called enterocins or as probiotics, live cells with different beneficial characteristics such as stimulation of immunity, anti-inflammatory activity, hypocholesterolemic effect, and prevention/treatment of some diseases. However, in the last years, the use of enterococci in foods or as probiotics caused an important debate because of their opportunistic pathogenicity implicated in several nosocomial infections due to virulence factors and antibiotic resistance, particularly the emergence of vancomycin-resistant enterococci. These virulence traits of some enterococci are associated with genetic transfer mechanisms. Therefore, the development of new enterococcal probiotics needs a strict assessment with regard to safety aspects for selecting the truly harmless enterococcal strains for safe applications. This review tries to give some data of the different points of view about this question.

Influence of the intestinal microbiota on disease susceptibility in kittens with experimentally-induced carriage of atypical enteropathogenic Escherichia coli

Typical enteropathogenic E. coli (tEPEC) carries the highest hazard of death in children with diarrhea and atypical EPEC (aEPEC) was recently identified as significantly associated with diarrheal mortality in kittens. In both children and kittens there is a significant association between aEPEC burden and diarrheal disease, however the infection can be found in individuals with and without diarrhea. It remains unclear to what extent, under what conditions, or by what mechanisms aEPEC serves as a primary pathogen in individuals with diarrhea. It seems likely that a combination of host and bacterial factors enable aEPEC to cause disease in some individuals and not in others. The purpose of this study was to determine the impact of aEPEC on intestinal function and diarrhea in kittens following experimentally-induced carriage and the influence of a disrupted intestinal microbiota on disease susceptibility. Results of this study identify aEPEC as a potential pathogen in kittens. In the absence of disruption to the intestinal microbiota, kittens are resistant to clinical signs of aEPEC carriage but demonstrate significant occult changes in intestinal absorption and permeability. Antibiotic-induced disruption of the intestinal microbiota prior to infection increases subsequent intestinal water loss as determined by % fecal wet weight. Enrichment of the intestinal microbiota with a commensal member of the feline mucosa-associated microbiota, Enterococcus hirae, ameliorated the effects of aEPEC experimental infection on intestinal function and water loss. These observations begin to unravel the mechanisms by which aEPEC infection may be able to exploit susceptible hosts.

Characteristics of Dogs with Biofilm-Forming Escherichia Coli Urinary Tract Infections

BACKGROUND

Bacterial urinary tract infections (UTIs) are common in companion animals. Increasing awareness of biofilm-forming bacteria raises concern regarding the appropriate diagnosis, treatment, and prognosis of UTIs associated with these organisms.

HYPOTHESIS/OBJECTIVES

To (1) describe the population of dogs with UTIs associated with biofilm-forming Escherichia coli and (2) determine whether or not clinical differences exist between dogs with biofilm-forming E. coli UTIs and dogs with nonbiofilm-forming E. coli UTIs. We hypothesized that there would be no difference in the population characteristics, but that biofilm-formation would be more prevalent in dogs with chronic, complicated, and asymptomatic UTIs.

ANIMALS

Seventy-six client-owned dogs with E. coli UTIs, divided into 2 groups based on the biofilm-forming capability of stored bacterial isolates as assessed by the crystal violet assay.

METHODS

Retrospective cross-sectional study. Medical records of the affected dogs were reviewed and their population and infection characteristics were compared.

RESULTS

Most (52.6%) E. coli isolates were capable of forming biofilms. Biofilm-forming E. coli had a lower likelihood (P < .001) of multidrug resistance than did nonbiofilm-forming E. coli. No statistically significant differences were identified between the population or infection characteristics of the 2 groups of dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Escherichia coli isolated from canine urinary tracts are frequently capable of forming biofilms. Because no reliable clinical features allowed exclusion of biofilm formation, the potential for biofilm formation should be considered whenever E. coli UTI is diagnosed. The association of antibiotic resistance and biofilm potential may affect treatment of UTIs, but additional investigation is warranted.

Model of Chronic Equine Endometritis Involving a Pseudomonas aeruginosa Biofilm

Bacteria in a biofilm community have increased tolerance to antimicrobial therapy. To characterize the role of biofilms in equine endometritis, six mares were inoculated with lux-engineered Pseudomonas aeruginosa strains isolated from equine uterine infections. Following establishment of infection, the horses were euthanized and the endometrial surfaces were imaged for luminescence to localize adherent lux-labeled bacteria. Samples from the endometrium were collected for cytology, histopathology, carbohydrate analysis, and expression of inflammatory cytokine genes. Tissue-adherent bacteria were present in focal areas between endometrial folds (6/6 mares). The Pel exopolysaccharide (biofilm matrix component) and cyclic di-GMP (biofilm-regulatory molecule) were detected in 6/6 mares and 5/6 mares, respectively, from endometrial samples with tissue-adherent bacteria (P < 0.05). A greater incidence (P < 0.05) of Pel exopolysaccharide was present in samples fixed with Bouin's solution (18/18) than in buffered formalin (0/18), indicating that Bouin's solution is more appropriate for detecting bacteria adherent to the endometrium. There were no differences (P > 0.05) in the number of inflammatory cells in the endometrium between areas with and without tissue-adherent bacteria. Neutrophils were decreased (P < 0.05) in areas surrounding tissue-adherent bacteria compared to those in areas free of adherent bacteria. Gene expression of interleukin-10, an immune-modulatory cytokine, was significantly (P < 0.05) increased in areas of tissue-adherent bacteria compared to that in endometrium absent of biofilm. These findings indicate that P. aeruginosa produces a biofilm in the uterus and that the host immune response is modulated focally around areas with biofilm, but inflammation within the tissue is similar in areas with and without biofilm matrix. Future studies will focus on therapeutic options for elimination of bacterial biofilm in the equine uterus.

Genomic insights into the pathogenicity and environmental adaptability of Enterococcus hirae R17 isolated from pork offered for retail sale

Genetic information about Enterococcus hirae is limited, a feature that has compromised our understanding of these clinically challenging bacteria. In this study, comparative analysis was performed of E. hirae R17, a daptomycin‐resistant strain isolated from pork purchased from a retail market in Beijing, China, and three other enterococcal genomes (Enterococcus faecium DO, Enterococcus faecalis V583, and E. hirae ATCC^™9790). Some 1,412 genes were identified that represented the core genome together with an additional 139 genes that were specific to E. hirae R17. The functions of these R17 strain‐specific coding sequences relate to the COGs categories of carbohydrate transport and metabolism and transcription, a finding that suggests the carbohydrate utilization capacity of E. hirae R17 may be more extensive when compared with the other three bacterial species (spp.). Analysis of genomic islands and virulence genes highlighted the potential that horizontal gene transfer played as a contributor of variations in pathogenicity in this isolate. Drug‐resistance gene prediction and antibiotic susceptibility testing indicated E. hirae R17 was resistant to several antimicrobial compounds, including bacitracin, ciprofloxacin, daptomycin, erythromycin, and tetracycline, thereby limiting chemotherapeutic treatment options. Further, tolerance to biocides and metals may confer a phenotype that facilitates the survival and adaptation of this isolate against food preservatives, disinfectants, and antibacterial coatings. The genomic plasticity, mediated by IS elements, transposases, and tandem repeats, identified in the E. hirae R17 genome may support adaptation to new environmental niches, such as those that are found in hospitalized patients. A predicted transmissible plasmid, pRZ1, was found to carry several antimicrobial determinants, along with some predicted pathogenic genes. These data supported the previously determined phenotype confirming that the foodborne E. hirae R17 is a multidrug‐resistant pathogenic bacterium with evident genome plasticity and environmental adaptability.

Association of Atypical Enteropathogenic Escherichia coli with Diarrhea and Related Mortality in Kittens

Diarrhea is responsible for the death of approximately 900,000 children per year worldwide. In children, typical enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea and is associated with a higher hazard of death. Typical EPEC infection is rare in animals and poorly reproduced in experimental animal models. In contrast, atypical EPEC (aEPEC) infection is common in both children and animals, but its role in diarrhea is uncertain. Mortality in kittens is often attributed to diarrhea, and we previously identified enteroadherent EPEC in the intestines of deceased kittens. The purpose of this study was to determine the prevalence and type of EPEC in kittens and whether infection was associated with diarrhea, diarrhea-related mortality, gastrointestinal pathology, or other risk factors. Kittens with and without diarrhea were obtained from two shelter facilities and determined to shed atypical EPEC at a culture-based prevalence of 18%. In contrast, quantitative PCR detected the presence of the gene for intimin (eae) in feces from 42% of kittens. aEPEC was isolated from kittens with and without diarrhea. However, kittens with diarrhea harbored significantly larger quantities of aEPEC than kittens without diarrhea. Kittens with aEPEC had a significantly greater severity of small intestinal and colonic lesions and were significantly more likely to have required subcutaneous fluid administration. These findings identify aEPEC to be prevalent in kittens and a significant primary or contributing cause of intestinal inflammation, diarrhea, dehydration, and associated mortality in kittens.

Enterococcus hirae and Barnesiella intestinihominis Facilitate Cyclophosphamide-Induced Therapeutic Immunomodulatory Effects

The efficacy of the anti-cancer immunomodulatory agent cyclophosphamide (CTX) relies on intestinal bacteria. How and which relevant bacterial species are involved in tumor immunosurveillance, and their mechanism of action are unclear. Here, we identified two bacterial species, Enterococcus hirae and Barnesiella intestinihominis that are involved during CTX therapy. Whereas E. hirae translocated from the small intestine to secondary lymphoid organs and increased the intratumoral CD8/Treg ratio, B. intestinihominis accumulated in the colon and promoted the infiltration of IFN-γ-producing γδT cells in cancer lesions. The immune sensor, NOD2, limited CTX-induced cancer immunosurveillance and the bioactivity of these microbes. Finally, E. hirae and B. intestinihominis specific-memory Th1 cell immune responses selectively predicted longer progression-free survival in advanced lung and ovarian cancer patients treated with chemo-immunotherapy. Altogether, E. hirae and B. intestinihominis represent valuable "oncomicrobiotics" ameliorating the efficacy of the most common alkylating immunomodulatory compound.

Enterococcus faecalis urinary-tract infections: Do they have a zoonotic origin?

Major human pathogens are frequently isolated from meat-producing animals, particularly poultry. Among them is Enterococcus faecalis, which is known to be one of the main cause of human urinary-tract infections worldwide. Early in 2015, we detected several, consecutive abnormal increases in the weekly number of human E. faecalis infections in various medical settings in the Provence-Alpes-Côte d'Azur region of France, especially including community-acquired urinary-tract infections. Speculating that this region-wide epidemiological event may have originated from animal-based food, we initiated this work to provide an overview of the epidemiology of E. faecalis, with a particular focus on the possible link between E. faecalis clones isolated from food-producing animals and those responsible for human urinary-tract infections. At that time, only one study had clearly identified strong epidemiological links between E. faecalis clones isolated from food-producing animals and human E. faecalis urinary-tract infections. This observation, coupled with our region-wide epidemiological experience, leads us to strongly believe that E. faecalis is a real zoonotic pathogen with potentially highly significant impact on human health. This is of particular concern because of its ability to acquire antibiotic-resistance genes and to infect animals and humans. Various strategies must be urgently implemented to address this public health threat, in particular through the development and implementation of large integrated automated surveillance systems based on animal and human health data to enable us to detect E. faecalis epidemiological events.

Antimicrobial resistance and virulence profiles of Enterococcus spp. isolated from horses in korea

Antimicrobial-resistant (AR) enterococci have emerged as leading nosocomial pathogens. Transmission of AR Enterococci from animals to humans has been demonstrated. However, there is limited information on the transmission of enterococci from horses to humans. To address this issue, we characterized 260 enterococci isolated from horse-associated samples in Korea in 2013 based on their AR profiles and virulence traits. AR profiling revealed an average ratio of AR enterococci of 23.8%. Seven isolates (2.7%) were multidrug-resistant Enterococcus faecalis. Most tetracycline-resistant enterococci harbored either tetM or tetL or both genes; genes conferring resistance to other antimicrobials were detected at low rates. Biofilm formation and gelatinase activity were observed in 51.1% and 47.7% of isolates, respectively; most were E. faecalis harboring the gelE gene. Evidence of transmission of AR enterococci between horses and their environments was provided by pulsed-field gel electrophoresis, and highlights the risk of AR enterococcus transmission to horse riders and handlers through close contact.

In Vitro Efficacy of Nonantibiotic Treatments on Biofilm Disruption of Gram-Negative Pathogens and an In Vivo Model of Infectious Endometritis Utilizing Isolates from the Equine Uterus

In this study, we evaluated the ability of the equine clinical treatments N-acetylcysteine, EDTA, and hydrogen peroxide to disrupt in vitro biofilms and kill equine reproductive pathogens (Escherichia coli, Pseudomonas aeruginosa, or Klebsiella pneumoniae) isolated from clinical cases. N-acetylcysteine (3.3%) decreased biofilm biomass and killed bacteria within the biofilms of E. coli isolates. The CFU of recoverable P. aeruginosa and K. pneumoniae isolates were decreased, but the biofilm biomass was unchanged. Exposure to hydrogen peroxide (1%) decreased the biofilm biomass and reduced the CFU of E. coli isolates, K. pneumoniae isolates were observed to have a reduction in CFU, and minimal effects were observed for P. aeruginosa isolates. Chelating agents (EDTA formulations) reduced E. coli CFU but were ineffective at disrupting preformed biofilms or decreasing the CFU of P. aeruginosa and K. pneumoniae within a biofilm. No single nonantibiotic treatment commonly used in equine veterinary practice was able to reduce the CFU and biofilm biomass of all three Gram-negative species of bacteria evaluated. An in vivo equine model of infectious endometritis was also developed to monitor biofilm formation, utilizing bioluminescence imaging with equine P. aeruginosa isolates from this study. Following infection, the endometrial surface contained focal areas of bacterial growth encased in a strongly adherent "biofilm-like" matrix, suggesting that biofilms are present during clinical cases of infectious equine endometritis. Our results indicate that Gram-negative bacteria isolated from the equine uterus are capable of producing a biofilm in vitro, and P. aeruginosa is capable of producing biofilm-like material in vivo.

The Microbiome: The Trillions of Microorganisms That Maintain Health and Cause Disease in Humans and Companion Animals

The microbiome is the complex collection of microorganisms, their genes, and their metabolites, colonizing the human and animal mucosal surfaces, digestive tract, and skin. It is now well known that the microbiome interacts with its host, assisting in digestion and detoxification, supporting immunity, protecting against pathogens, and maintaining health. Studies published to date have demonstrated that healthy individuals are often colonized with different microbiomes than those with disease involving various organ systems. This review covers a brief history of the development of the microbiome field, the main objectives of the Human Microbiome Project, and the most common microbiomes inhabiting the human respiratory tract, companion animal digestive tract, and skin in humans and companion animals. The main changes in the microbiomes in patients with pulmonary, gastrointestinal, and cutaneous lesions are described.

Microbiota alterations in acute and chronic gastrointestinal inflammation of cats and dogs

The intestinal microbiota is the collection of the living microorganisms (bacteria, fungi, protozoa, and viruses) inhabiting the gastrointestinal tract. Novel bacterial identification approaches have revealed that the gastrointestinal microbiota of dogs and cats is, similarly to humans, a highly complex ecosystem. Studies in dogs and cats have demonstrated that acute and chronic gastrointestinal diseases, including inflammatory bowel disease (IBD), are associated with alterations in the small intestinal and fecal microbial communities. Of interest is that these alterations are generally similar to the dysbiosis observed in humans with IBD or animal models of intestinal inflammation, suggesting that microbial responses to inflammatory conditions of the gut are conserved across mammalian host types. Studies have also revealed possible underlying susceptibilities in the innate immune system of dogs and cats with IBD, which further demonstrate the intricate relationship between gut microbiota and host health. Commonly identified microbiome changes in IBD are decreases in bacterial groups within the phyla Firmicutes and Bacteroidetes, and increases within Proteobacteia. Furthermore, a reduction in the diversity of Clostridium clusters XIVa and IV (i.e., Lachnospiraceae and Clostridium coccoides subgroups) are associated with IBD, suggesting that these bacterial groups may play an important role in maintenance of gastrointestinal health. Future studies are warranted to evaluate the functional changes associated with intestinal dysbiosis in dogs and cats.