Household Pet Ownership and the Microbial Diversity of the Human Gut Microbiota.

The human gut microbiome has a great deal of interpersonal variation due to both endogenous and exogenous factors, like household pet exposure. To examine the relationship between having a pet in the home and the composition and diversity of the adult gut microbiome, we conducted a case-control study nested in a larger, statewide study, the Survey of the Health of Wisconsin. Stool samples were collected from 332 participants from unique households and analyzed using 16S rRNA sequencing on the Illumina MiSeq. One hundred and seventy-eight participants had some type of pet in the home with dogs and cats being the most prevalent. We observed no difference in alpha and beta diversity between those with and without pets, though seven OTUs were significantly more abundant in those without pets compared to those with pets, and four were significantly more abundant in those with pets. When stratifying by age, seven of these remained significant. These results suggest that pet ownership is associated with differences in the human gut microbiota. Further research is needed to better characterize the effect of pet ownership on the human gut microbiome.

A Prospective, Randomized Comparison of Duodenoscope Reprocessing Surveillance Methods.

Duodenoscope use in healthcare facilities has been associated with transmission of multidrug resistant pathogens between patients. To assist healthcare facilities in monitoring the quality of their duodenoscope reprocessing procedures and limit patient risk of infection, the Centers for Disease Control and Prevention (CDC) deployed voluntary interim duodenoscope sampling and culturing surveillance protocols in 2015. Though the interim methods were widely adopted, alternative surveillance protocols were developed and implemented at individual institutions. Here, we compared two sampling methods-the 2015 CDC interim protocol and an alternative protocol developed by the University of Wisconsin Hospitals and Clinics (UWHC). We hypothesized that the UWHC protocol would detect a higher incidence of bacterial contamination from reprocessed duodenoscopes. A total of 248 sampling events were performed at UWHC. The CDC protocol (n = 129 sampling events) required culturing samples collected from each duodenoscope after brushing its terminal end and flushing its lumen with sterile water. The UWHC protocol (n = 119 sampling events) required culturing samples collected from each duodenoscope after swabbing its elevator, immersing its terminal end into broth and flushing its lumen with saline. With the CDC method, 8.53% (n = 11) of the duodenoscopes sampled were positive for bacterial growth with 15 isolates recovered. Using the UWHC method, 15.13% (n = 18) of cultures were positive for bacterial growth with 20 isolates recovered. The relative risk of identifying a contaminated duodenoscope using the CDC interim method, however, was not different than when using the UWHC protocol. Mean processing time (27.35 and 5.11 minutes, p < 0.001) and total cost per sample event ($17.87 and $15.04) were lower using the UWHC method. As the UWHC protocol provides similar detection rates as the CDC protocol, the UWHC method is useful, provided the shorter processing time and lower cost to perform.

Wisconsin microbiome study, a cross-sectional investigation of dietary fibre, microbiome composition and antibiotic-resistant organisms: rationale and methods.

INTRODUCTION: Prevention of multidrug-resistant organism (MDRO) infections, such as those caused by methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, fluoroquinolone-resistant Gram-negative bacteria and Clostridium difficile is crucial. Evidence suggests that dietary fibre increases gut microbial diversity, which may help prevent colonisation and subsequent infection by MDROs. The aim of the Winning the War on Antibiotic Resistance (WARRIOR) project is to examine associations of dietary fibre consumption with the composition of the gut microbiota and gut colonisation by MDROs. The secondary purpose of the study is to create a biorepository of multiple body site specimens for future microbiota research. METHODS AND ANALYSIS: The WARRIOR project collects biological specimens, including nasal, oral and skin swabs and saliva and stool samples, along with extensive data on diet and MDRO risk factors, as an ancillary study of the Survey of the Health of Wisconsin (SHOW). The SHOW is a population-based health survey collecting data on several different health determinants and outcomes, as well as objective body measurements and biological specimens. WARRIOR participants include 600 randomly selected Wisconsin residents age 18 and over. Specimens are screened for MDRO colonisation and DNA is extracted for 16S ribosomal RNA-based microbiota sequencing. Data will be analysed to assess the relationship between dietary fibre, the gut microbiota composition and gut MDRO colonisation. ETHICS AND DISSEMINATION: The WARRIOR project is approved by the University of Wisconsin Institutional Review Board. The main results of this study will be published in a peer-reviewed scientific journal.

Effect of Lactobacillus rhamnosus HN001 on carriage of Staphylococcus aureus: results of the impact of probiotics for reducing infections in veterans (IMPROVE) study.

BACKGROUND: Infection by Staphylococcus aureus (S. aureus) is a major cause of morbidity and mortality. Colonization by S. aureus increases the risk of infection. Little is known about decolonization strategies for S. aureus beyond antibiotics, however probiotics represent a promising alternative. A randomized controlled trial was conducted to determine the efficacy of Lactobacillus rhamnosus (L. rhamnosus) HN001 in reducing carriage of S. aureus at multiple body sites. METHODS: One hundred thirteen subjects, positive for S. aureus carriage, were recruited from the William S. Middleton Memorial Medical Center, Madison, WI, USA, and randomized by initial site of colonization, either gastrointestinal (GI) or extra-GI, to 4-weeks of oral L. rhamnosus HN001 probiotic, or placebo. Nasal, oropharyngeal, and axillary/groin swabs were obtained, and serial blood and fecal samples were collected. Differences in prevalence of S. aureus carriage at the end of the 4-weeks of treatment were assessed. RESULTS: The probiotic and placebo groups were similar in age, gender, and health history at baseline. S. aureus colonization within the stool samples of the extra-GI group was 15% lower in the probiotic than placebo group at the endpoint of the trial. Those in the probiotic group compared to the placebo group had 73% reduced odds (OR 0.27, 95% CI 0.07-0.98) of methicillin-susceptible S. aureus presence, and 83% reduced odds (OR 0.17, 95% CI 0.04-0.73) of any S. aureus presence in the stool sample at endpoint. CONCLUSION: Use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01321606 . Registered March 21, 2011.

On the hands of patients with Clostridium difficile: A study of spore prevalence and the effect of hand hygiene on C difficile removal.

The prevalence of Clostridium difficile spores was assessed in 48 observations of infected inpatients. Participants were randomized to hand hygiene with either alcohol-based handrub or soap and water. C difficile was recovered in 14.6% of pre-hand hygiene observations. It was still present on 5 of these 7 participants after hand hygiene (3/3 using alcohol-based handrub; 2/4 using soap and water).

A randomized controlled trial of probiotics for Clostridium difficile infection in adults (PICO).

BACKGROUND: Clostridium difficile is the most common cause of hospital-acquired infections, responsible for >450000 infections annually in the USA. Probiotics provide a promising, well-tolerated adjunct therapy to standard C. difficile infection (CDI) treatment regimens, but there is a paucity of data regarding their effectiveness for the treatment of an initial CDI. OBJECTIVES: We conducted a pilot randomized controlled trial of 33 participants from February 2013 to February 2015 to determine the feasibility and health outcomes of adjunct probiotic use in patients with an initial mild to moderate CDI. METHODS: The intervention was a 28 day, once-daily course of a four-strain oral probiotic capsule containing Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bi-07 and B. lactis Bl-04. The control placebo was identical in taste and appearance. Registered at clinicaltrials.gov: trial registration number = NCT01680874. RESULTS: Probiotic adjunct therapy was associated with a significant improvement in diarrhoea outcomes. The primary duration of diarrhoea outcome (0.0 versus 1.0 days; P = 0.039) and two exploratory outcomes, total diarrhoea days (3.5 versus 12.0 days; P = 0.005) and rate of diarrhoea (0.1 versus 0.3 days of diarrhoea/stool diary days submitted; P = 0.009), all decreased in participants with probiotic use compared with placebo. There was no significant difference in the rate of CDI recurrence or functional improvement over time between treatment groups. CONCLUSIONS: Probiotics are a promising adjunct therapy for treatment of an initial CDI and should be further explored in a larger randomized controlled trial.

Chemical Genomics, Structure Elucidation, and in Vivo Studies of the Marine-Derived Anticlostridial Ecteinamycin.

A polyether antibiotic, ecteinamycin (1), was isolated from a marine Actinomadura sp., cultivated from the ascidian Ecteinascidia turbinata. 13C enrichment, high resolution NMR spectroscopy, and molecular modeling enabled elucidation of the structure of 1, which was validated on the basis of comparisons with its recently reported crystal structure. Importantly, ecteinamycin demonstrated potent activity against the toxigenic strain of Clostridium difficile NAP1/B1/027 (MIC = 59 ng/µL), as well as other toxigenic and nontoxigenic C. difficile isolates both in vitro and in vivo. Additionally, chemical genomics studies using Escherichia coli barcoded deletion mutants led to the identification of sensitive mutants such as trkA and kdpD involved in potassium cation transport and homeostasis supporting a mechanistic proposal that ecteinamycin acts as an ionophore antibiotic. This is the first antibacterial agent whose mechanism of action has been studied using E. coli chemical genomics. On the basis of these data, we propose ecteinamycin as an ionophore antibiotic that causes C. difficile detoxification and cell death via potassium transport dysregulation.

Serratia marcescens Bacteremia: Nosocomial Cluster Following Narcotic Diversion.

OBJECTIVE To describe the investigation and control of a cluster of Serratia marcescens bacteremia in a 505-bed tertiary-care center. METHODS Cluster cases were defined as all patients with S. marcescens bacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio. RESULTS In total, 6 patients developed S. marcescens bacteremia within 48 hours after admission within the above period. Of these, 5 patients had identical Serratia isolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employee's job was terminated. CONCLUSION Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting. Infect Control Hosp Epidemiol 2017;38:1027-1031.

Risk of Clostridium difficile Infection in Hematology-Oncology Patients Colonized With Toxigenic C. difficile.

The prevalence of colonization with toxigenic Clostridium difficile among patients with hematological malignancies and/or bone marrow transplant at admission to a 566-bed academic medical care center was 9.3%, and 13.3% of colonized patients developed symptomatic disease during hospitalization. This population may benefit from targeted C. difficile infection control interventions. Infect Control Hosp Epidemiol 2017;38:718-720.

Macrolide and Clindamycin Resistance in Group a Streptococci Isolated From Children With Pharyngitis.

Group A streptococcus (GAS) is responsible for 15%-30% of cases of acute pharyngitis in children. Macrolides such as azithromycin have become popular for treating GAS pharyngitis. We report macrolide resistance rates in a primary care setting in our geographic area over the past 5 years and discuss the implications of resistance in making treatment decisions. Throat swabs were collected from children with pharyngitis from May 2011 to May 2015 in a primary care setting in Madison, Wisconsin. Susceptibility testing was performed for erythromycin and clindamycin using the Kirby-Bauer disk diffusion method. GAS was identified on 143 throat cultures. Overall, 15% of GAS isolates demonstrated nonsusceptibility for both clindamycin and erythromycin. Inducible resistance (positive D-test) was detected in 17 isolates (12%). The rate of detection of nonsusceptibility in each year of the study did not change over time. Azithromycin should only be used for patients with pharyngitis and substantial manifestations of penicillin hypersensitivity and when used, susceptibility testing should always be performed.

Impact of Probiotics for Reducing Infections in Veterans (IMPROVE): Study protocol for a double-blind, randomized controlled trial to reduce carriage of Staphylococcus aureus.

BACKGROUND: Staphylococcus aureus (S. aureus) is an organism of great public health importance, causing 20,000 deaths annually. Decolonization of patients with S. aureus may prevent infections, yet current options are limited to antimicrobials that promote antibiotic resistance and can cause adverse side effects. Probiotics have potential to reduce colonization of pathogenic bacteria, representing a promising alternative for S. aureus decolonization, but thus far lack rigorous evaluation. METHODS: Potential subjects were recruited from inpatient and outpatient settings within a VA medical center and screened for S. aureus gastrointestinal (GI) or extra-GI colonization using swabs at multiple body sites. Positive, eligible, consenting participants were stratified by colonization site and randomized in a 1:1 ratio to 4-weeks of daily placebo or Lactobacillus rhamnosus (L. rhamnosus) HN001 probiotic treatment. Blood and stool samples, and treatment adherence reports were collected from each subject throughout the study, along with a final set of swabs at study completion to detect S. aureus carriage. The outcomes of this study are GI or extra-GI carriage by S. aureus at the end of 4weeks of therapy, change in phagocytic activity of polymorphonuclear cells from pre-intervention to post-intervention, and symptomatic S. aureus infection at any site during the study period. CONCLUSION: 114 participants have been recruited for this study. Analysis of outcomes is underway. This is the first clinical trial to examine the efficacy of L. rhamnosus HN001 for decolonization of S. aureus, and investigates the mechanism by which L. rhamnosus HN001 mediates its effect on S. aureus colonization. ClinicalTrials.govIdentifier NCT01321606.

Vancomycin-resistant Enterococcus co-colonization rates with methicillin-resistant Staphylococcus aureus and Clostridium difficile in critically ill veterans.

A prospective study was conducted to identify risk factors for vancomycin-resistant Enterococcus, including co-colonization with methicillin-resistant Staphylococcus aureus and Clostridium difficile infection in patients admitted to the intensive care unit in 2 Veterans Affairs facilities. Methicillin-resistant Staphylococcus aureus and Clostridium difficile infection co-colonization were significant risk factors for vancomycin-resistant Enterococcus colonization. Further studies are needed to identify measures for preventing co-colonization of these major organisms in veterans.

Feasibility and patient satisfaction with smoking cessation interventions for prevention of healthcare-associated infections in inpatients.

BACKGROUND: Smoking increases hospitalization and healthcare-associated infection. Our primary aim of this pilot, randomized-controlled trial was to examine the feasibility and acceptability of a tobacco cessation intervention compared with usual care in inpatients. S. aureus carriage, healthcare-associated infections and infections post discharge were exploratory outcomes. METHODS: Current inpatient smokers from a university hospital facility were randomized to usual care or a face to face tobacco cessation counseling session where patients' tobacco use and strategies for quitting were discussed. Patient engagement, satisfaction and withdrawal symptoms were measured at 1 week and 12 weeks post discharge. Nasal swabs were collected at enrollment and discharge and assessed for S. aureus colonization. P-values were calculated using Fisher's exact and t-tests were used to compare groups. RESULTS: For the study's primary outcome, participants reported the intervention as being generally acceptable and reported high overall levels of satisfaction, with a Likert scale score of at least 4/5 for all measures of satisfaction. No subjects utilized free tobacco cessation services after discharge. 83 % of the intervention group and 93 % of the control group smoked at least one cigarette after discharge. Secondary outcomes with regard to infections showed that, at discharge, 12 % of the intervention group (n = 17) and 18 % of the control group (n = 22) tested positive for S. aureus. After 3 months, 9 % of the intervention group developed infection, 41 % visited an emergency room, and 24 % were readmitted within 3 months post-discharge, compared to 27, 32 and 36 % of the control group respectively. CONCLUSIONS: With regards to the primary aim of this study, there were overall high levels of satisfaction with the intervention, indicating good feasibility and acceptance among patients. However, more intensive interventions in hospitalized patients and impact on healthcare-associated infections and post-discharge infections should be explored.

Effect of United States buckwheat honey on antibiotic-resistant hospital acquired pathogens.

INTRODUCTION: Due to an upsurge in antibiotic-resistant infections and lack of therapeutic options, new approaches are needed for treatment. Honey may be one such potential therapeutic option. We investigated the susceptibility of hospital acquired pathogens to four honeys from Wisconsin, United States, and then determined if the antibacterial effect of each honey against these pathogens is primarily due to the high sugar content. METHODS: Thirteen pathogens including: four Clostridium difficile, two Methicillin-resistant Staphylococcus aureus, two Pseudomonas aeruginosa, one Methicillin-Susceptible Staphylococcus aureus, two Vancomycin-resistance Enterococcus, one Enterococcus faecalis and one Klebsiella pneumoniae were exposed to 1-50% (w/v) four Wisconsin honeys and Artificial honey to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the broth dilution method. RESULTS: Buckwheat honey predominantly exhibited a bactericidal mode of action against the tested pathogens, and this varied with each pathogen. C. difficile isolates were more sensitive to the Wisconsin buckwheat honey as compared to the other pathogens. Artificial honey at 50% (w/v) failed to kill any of the pathogens. The high sugar content of Wisconsin buckwheat honey is not the only factor responsible for its bactericidal activity. CONCLUSION: Wisconsin buckwheat honey has the potential to be an important addition to therapeutic armamentarium against resistant pathogens and should be investigated further.

Risk factors for Candida colonization and Co-colonization with multi-drug resistant organisms at admission.

INTRODUCTION: Candida species are major causes of healthcare-associated infections with colonization preceding infection. Understanding risk factors for colonization by Candida species is important in prevention. However, data on risk factors for colonization by Candida species alone or with other healthcare-associated pathogens is limited. METHODS: From 2002 to 2006, 498 patients were enrolled into a prospective cohort study at our institution. Surveillance perirectal, nasal and skin swab samples were obtained upon enrollment. Samples were cultured for the presence of Candida species, Methicillin Resistant Staphylococcus aureus, Vancomycin Resistant Enterococcus, and Resistant Gram Negative organisms. Data on demographics, comorbidities, device use, and antibiotic use were also collected for each subject and analyzed using univariate and multivariate logistic regression. RESULTS: Factors associated with Candida colonization at admission in univariate analysis included ambulatory status, a history of Candida colonization and the use of antibiotics prior to enrollment. In multivariate analysis, ambulatory status (odds ratio; OR = 0.45, 95 % CI: 0.27-0.73) and fluroquinolone use (OR = 3.01, 95 % CI: 1.80-5.01) were associated with Candida colonization at admission. Factors predicting Candida co-colonization with one or more MDROs at admission in univariate analysis included, older age, malnutrition, days spent in an ICU in the 2 years prior to enrollment, a history of MRSA colonization, and using antibiotics prior to enrollment. In multivariate analysis malnutrition (OR = 3.97, 95 % CI: 1.80-8.78) a history of MRSA (OR = 5.51, 95 % CI: 1.89-16.04) and the use of macrolides (OR = 3.75, 95 % CI: 1.18-11.93) and other antibiotics (OR = 4.94, 95 % CI: 1.52-16.03) were associated with Candida co-colonization at admission. DISCUSSION: Antibiotic use was associated with an increased risk of colonization by Candida species alone and in conjunction with other multidrug-resistant organisms (MDROs). Antibiotic stewardship may be an important intervention for preventing colonization and subsequent infection by Candida and other MDROs.

Nontyphoidal Salmonella: An Occupational Hazard for Clinical Laboratory Workers.

Laboratory-acquired infections due to nontyphoidal Salmonella are rare. Yet, recent outbreaks in microbiology teaching laboratories show that these species are still an appreciable occupational hazard for laboratory employees. This article presents two cases of nontyphoidal Salmonella that occurred at the authors' institution-an infected patient and a clinical laboratory worker who acquired the infection by handling this patient's specimens.

Probiotics for Clostridium difficile infection in adults (PICO): Study protocol for a double-blind, randomized controlled trial.

BACKGROUND: Clostridium difficile is a pathogen of rapidly increasing public health importance. An estimated quarter of a million Clostridium difficile infections (CDI) occur in the United States annually, at a resultant cost of 14,000 deaths and 1 billion dollars. Clostridium difficile related deaths have risen 400% over the last decade, and current standard antibiotic treatments are only 75 to 85% successful. Besides increasing the risk of antibiotic resistance and side effects, these treatments are very expensive. The most vulnerable population for Clostridium difficile is older adults, who make up approximately half of the cases, but account for 90% of the related deaths. Probiotics may have potential as adjunctive therapeutic agents for CDIs, however, current data is limited. METHODS: This pilot study is a single-site, randomized, placebo-controlled, double-blind, phase two clinical trial. The trial primarily evaluates the effect of four weeks of probiotic therapy in addition to standard of care on Clostridium difficile diarrhea duration and recurrence. Secondary outcomes include effect on fecal cytokines, fecal lactoferrin, and Clostridium difficile toxin density in stool, as well as patient functional status. DISCUSSION: This pilot study will determine the feasibility and effect size to conduct larger randomized controlled trials of probiotic interventions in patients with CDI, to determine the impact of probiotics on the symptoms of CDI. ClinicalTrials.gov Identifier: NCT01680874.

The relationship between patient functional status and environmental contamination by Clostridium difficile: a pilot study.

INTRODUCTION: Limited data exist on patient factors related to environmental contamination with Clostridium difficile. METHODS: We evaluated the association between the functional status of patients with C. difficile infection (CDI) and environmental contamination with C. difficile. RESULTS: Contamination of patient rooms was frequent and higher functional status was associated with contaminated surfaces remote from the bed. All but one environmental isolates matched the corresponding patient's stool isolate for the seven patients tested. CONCLUSION: Functional status is a factor that influences environmental contamination with C. difficile. Future studies should evaluate strategies to reduce contamination in CDI patient rooms, taking into account the patient's functional status.

Feasibility of oral prenatal probiotics against maternal group B Streptococcus vaginal and rectal colonization.

OBJECTIVE: To examine the effect of an oral prenatal probiotic on group B Streptococcus (GBS) colonization and to demonstrate the feasibility of a larger randomized controlled trial. DESIGN: This pilot study was an open-label, two-group quasi-experiment. SETTING: An urban central city nurse-midwifery and wellness center serving a diverse population. PARTICIPANTS: Ten pregnant participants received the oral probiotic (Florajen3) taken once daily, and 10 participants served as controls. METHODS: A questionnaire on dietary practices, vaginal cleansing, sexual history, and symptoms and GBS colony count samples were taken at 28-, 32-, and 36-weeks gestation. RESULTS: Participants in the probiotic group reported no adverse events or minor side effects; one half reported improved gastrointestinal symptoms. Although two women in each group had positive qualitative prenatal GBS cultures at 36 weeks, the probiotic group participants had lower quantitative GBS colony counts. The eight GBS negative averaged 90% probiotic adherence compared with two GBS positive women who averaged 68%. Yogurt ingestion was inversely related (p = .02) to GBS colonization. CONCLUSIONS: Prenatal probiotic therapy has the potential to reduce GBS colonization. The potential of the probiotic intervention appears to be linked to daily adherence. A controlled clinical trial with a larger, adequately powered sample is feasible and justified.

Clostridium difficile in a children's hospital: assessment of environmental contamination.

Clostridium difficile infection (CDI) is the most frequent infectious cause of health care-associated diarrhea. Three cases of CDI, in children age 2, 3, and 14 years, occurred in the hematology/oncology ward of our children's hospital over 48 hours. We aimed to assess environmental contamination with C difficile in the shared areas of this unit, and to determine whether person-to-person transmission occurred. C difficile was recovered from 5 of 18 samples (28%). We compared C difficile isolated from each patient and the environment using pulsed-field gel electrophoresis, and found that none of the patient strains matched any of the others, and that none matched any strains recovered from the environment, suggesting that person-to-person transmission had not occurred. We found that C difficile was prevalent in the environment throughout shared areas of the children's hospital unit. Molecular typing to identify mechanisms of transmission is useful for devising appropriate interventions.