Simone Warrack

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 childrens 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 childrens hospital unit. Molecular typing to identify mechanisms of transmission is useful for devising appropriate interventions.

Comparison of Pulsed-Gel Electrophoresis and a Commercial Repetitive-Element PCR Method for Assessment of Methicillin-Resistant Staphylococcus aureus Clustering in Different Health Care Facilities

ABSTRACT Pulsed-field gel electrophoresis (PFGE) is a common method used to type methicillin-resistant Staphylococcus aureus (MRSA) in nosocomial investigations and epidemiological studies but is time-consuming and methodologically challenging. We compared typing results obtained using a commercial repetitive-element PCR (rep-PCR) system with PFGE in a sample of 86 unique MRSA isolates recovered from subjects in an academic referral hospital and two nursing homes in the same geographic region. Both methods reliably assigned isolates to the same Centers for Disease Control and Prevention (CDC) pulsotype. PFGE was significantly more discriminatory (Simpsons index of diversity, 0.92 at the 95% strain similarity threshold) than the commercial rep-PCR system (Simpsons index of diversity, 0.58). The global (adjusted Rand coefficient, 0.10) and directional congruence (adjusted Wallace coefficientrepPCR→PFGE = 0.06; adjusted Wallace coefficientPFGE→repPCR = 0.52) between the two methods was low. MRSA strains recovered from study nursing homes that were clonal when typed by the commercial rep-PCR method were frequently noted to be genetically distinct when typed using PFGE. These data suggest that the commercial rep-PCR has less utility than PFGE in small-scale epidemiological assessments of MRSA in health care settings.

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.

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

IntroductionLimited data exist on patient factors related to environmental contamination with Clostridium difficile.MethodsWe evaluated the association between the functional status of patients with C. difficile infection (CDI) and environmental contamination with C. difficile.ResultsContamination 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.ConclusionFunctional 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.

Tolerability of a probiotic in subjects with a history of methicillin-resistant Staphylococcus aureus colonisation.

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of major public health importance. Colonisation precedes infection; thus reducing MRSA carriage may be of benefit for reducing infection. Probiotics represent a novel approach to reducing MRSA carriage. We undertook a pilot feasibility randomised controlled trial of the tolerability and acceptability of probiotics for reducing nasal and intestinal carriage of MRSA. In addition, subjects were screened for vancomycin-resistant enterocococci (VRE). Subjects with a history of MRSA were recruited from a large, academic medical center and randomised to take either a placebo or probiotic (Lactobacillus rhamnosus HN001). Subjects returned to the clinic after four weeks for further testing to determine adherence to the probiotic regimen and colonisation of MRSA. 48 subjects were enrolled and randomised. Nearly 25% were transplant recipients and 30% had diabetes. The probiotic was well tolerated in the study population though minor side effects, such as nausea and bloating, were observed. A majority of the subjects randomised to HN001 had good adherence to the regimen. At the four week time point among subjects randomised to the probiotic, MRSA was detected in 67 and 50% of subjects colonised in the nares and the gastrointestinal tract, respectively. Three subjects who initially tested positive for VRE were negative after four weeks of probiotic exposure. Probiotics were well tolerated in our study population of largely immunocompromised subjects with multiple comorbidities. Adherence to the intervention was good. Probiotics should be studied further for their potential to reduce colonisation by multidrug resistant bacteria.

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.

Intra-Facility Acquisition of Methicillin-Resistant Staphylococcus aureus (MRSA) in Southern Wisconsin Skilled Nursing Facilities

Abstract Background Studies have shown that skilled nursing facilities (SNFs) are reservoirs for methicillin-resistant Staphylococcus aureus (MRSA). The extent to which resident-to-resident transmission accounts for the high burden of MRSA in these facilities remains poorly understood. The objective of this study was to estimate the frequency of intra-facility MRSA acquisition in a sample of SNFs participating in a longitduinal study in Wisconsin. Methods MRSA colonization among a cohort of 449 subjects residing in six SNFs in Southern Wisconsin was measured using serial, multi-anatomical surveillance culturing. Phenotypic acquisitions events (i.e., MRSA [-] to MRSA[+]) were identified and further characterized both temporally (calendar date) and genetically (pulse-field gel electrophoresis). An intra-facility acquisition event was defined as incident recovery of an MRSA isolate that was genetically identical to at least one other strain previously recovered in a study facility. A Marascuilo procedure for comparing multiple proportions was employed to determine whether the proportion of intra-facility MRSA acquisitions differed across study facilities. Linear regression was employed to assess if certain facility-level characteristics were associated with rates of intra-facility MRSA acquisition. Results 129 acquisition events were identified that met our criteria, of which 74 were determined to be intra-facility (57.4%) [95% CI: 45.5–67.6%]. Statistically significant differences were found between the intra-facility acquisition proportion of multiple SNFs. A facility’s baseline MRSA prevalence was significantly associated with its intra-facility MRSA acquisition rate (R2 = 0.784, P-value = 0.012). Conclusion Intra-facility acquisition represents a large proportion of the burden of MRSA observed in SNFs. The rate of intra-facility acquisition is variable between facilities but may, in part, be explained by the prevalent burden of MRSA in the facility (i.e., MRSA colonization pressure to characteristics of the facility). Whether other facility characteristics, including infection prevention practices are contributing to these transmission dynamics requires further study. Disclosures All authors: No reported disclosures.