Safety and efficacy of outpatient parenteral antibiotic therapy in an academic infectious disease clinic.

WHAT IS KNOWN AND OBJECTIVE: Outpatient parenteral therapy (OPAT) has become a safe and effective modality for patients requiring intravenous or prolonged antimicrobial therapy since the 1970s. It is being increasingly utilized in various settings; however, studies evaluating the safety and efficacy of clinic-based OPAT are limited. Since 2012, patients being considered for OPAT have required an infectious disease (ID) consultation at our institution. Candidates receiving once-daily antimicrobials who were ineligible for home infusion or nursing home placement as determined by their insurance companies and those who preferred the clinic over nursing home or home infusion were referred to the ID clinic. This study assessed the safety and outcome of patients receiving OPAT in an academic inner-city ID clinic in Detroit, Michigan. METHODS: This was a retrospective cross-sectional study of electronic medical records of patients, identified through clinic records, who received at least 2 days of OPAT from December 2012 to December 2015. Demographics, types of infections, antimicrobial regimen used, adverse events and outcome were evaluated. RESULTS: A total of 122 cases were identified during the study period. Mean age was 62 years with 55% male; 102 (84%) of 122 patients had peripherally inserted central catheter (PICC). Fifty-five per cent of patients participated in the clinic-based OPAT programme for insurance reasons, and 43% preferred the clinic over nursing home or home infusion. The most common infections were bone and joint (36%), followed by skin and soft tissue (18%) and urinary tract infections (12%). Ertapenem (44%) and daptomycin (41%) alone or in combination were used most frequently with 40% of patients receiving at least 4 weeks of treatment. Thirteen patients (11%) experienced one or more adverse drug events on daptomycin and/or ertapenem; of these, nine (69%) patients were receiving daptomycin monotherapy. Gastrointestinal symptoms (29%), cramping and myalgias (29%) and asymptomatic creatine phosphokinase (CPK) elevation (24%) were the most common adverse events. Three (3%) of 102 patients had PICC-related complications. Fourteen (88%) of 16 patients with adverse events or PICC-related complications required changing or stopping antibiotics; two (2%) had infection-related readmission. Conversely, 113 (93%) of 122 patients who completed treatment were considered cured and none had treatment failure at the end of 30 days of treatment. No patients died as a result of treatment or infection-related complications. WHAT IS NEW AND CONCLUSION: Outpatient parenteral therapy in our academic ID clinic was a safe and effective alternative to home infusion or skilled nursing facilities for patients requiring long-term antibiotics with few adverse events and complications.

Simplified risk stratification criteria for identification of patients with MRSA bacteremia at low risk of infective endocarditis: implications for avoiding routine transesophageal echocardiography in MRSA bacteremia.

The aim of this study was to identify patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with low risk of infective endocarditis (IE) who might not require routine trans-esophageal echocardiography (TEE). We retrospectively evaluated 398 patients presenting with MRSA bacteremia for the presence of the following clinical criteria: intravenous drug abuse (IVDA), long-term catheter, prolonged bacteremia, intra-cardiac device, prosthetic valve, hemodialysis dependency, vertebral/nonvertebral osteomyelitis, cardio-structural abnormality. IE was diagnosed using the modified Duke criteria. Of 398 patients with MRSA bacteremia, 26.4 % of cases were community-acquired, 56.3 % were health-care-associated, and 17.3 % were hospital-acquired. Of the group, 44 patients had definite IE, 119 had possible IE, and 235 had a rejected diagnosis. Out of 398 patients, 231 were evaluated with transthoracic echocardiography (TTE) or TEE. All 44 patients with definite IE fulfilled at least one criterion (sensitivity 100 %). Finally, a receiver operator characteristic (ROC) curve was obtained to evaluate the total risk score of our proposed criteria as a predictor of the presence of IE, and this was compared to the ROC curve of a previously proposed criteria. The area under the ROC curve for our criteria was 0.710, while the area under the ROC curve for the criteria previously proposed was 0.537 (p < 0.001). The p-value for comparing those 2 areas was less than 0.001, indicating statistical significance. Patients with MRSA bacteremia without any of our proposed clinical criteria have very low risk of developing IE and may not require routine TEE.

Transmission of infection to liver transplant recipients from donors with infective endocarditis: lessons learned.

Donors not meeting standard criteria, such as those with bacteremia, are now being used in response to the increasing need for organs for transplantation. Recommended strategies to prevent the occurrence of donor-derived bacteremia include the use of directed antibiotic prophylaxis. However, this approach does not eliminate the risk of infection transmission. Similarly, the management of organ recipients from donors with infective endocarditis (IE) remains uncharacterized. We report 2 cases of donor-derived bacterial infections in liver transplant recipients despite pathogen-specific antibiotic prophylaxis. In both instances, the donors had documented IE treated with appropriate antimicrobial therapy and clearance of bacteremia. Recipients had very distinctive clinical outcomes likely related to pathogen virulence and the extent of donor infection. Persistent infection in the transplanted liver should be suspected in organ recipients of a liver from donors with IE, despite the absence of bacteremia at the time of death and organ procurement. For eradication, recipients may require prolonged pathogen-directed antimicrobial therapy, such as is used for endovascular infections. Prompt recognition of donors with IE, appropriate notification, and prolonged antibiotic prophylaxis are key to reducing the risk of such donor-derived infections.

Electronic properties of the Sn1-xPbxO alloy and band alignment of the SnO/PbO system: a DFT study.

Tin monoxide (SnO) has attracted attention due to its p-type character and capability of ambipolar conductivity when properly doped, properties that are beneficial for the realization of complementary oxide thin film transistors technology, transparent flexible circuits and optoelectronic applications in general. However, its small fundamental band gap (0.7 eV) limits its applications as a solar energy material, therefore tuning its electronic properties is necessary for optimal performance. In this work, we use density functional theory (DFT) calculations to examine the electronic properties of the Sn1-xPbxO ternary oxide system. Alloying with Pb by element substitution increases the band gap of SnO without inducing defect states in the band gap retaining the anti-bonding character of the valence band maximum which is beneficial for p-type conductivity. We also examine the properties of the SnO/PbO heterojunction system in terms of band alignment and the effect of the most common intrinsic defects. A broken gap band alignment for the SnO/PbO heterojunction is calculated, which can be attractive for energy conversion in solar cells, photocatalysis and hydrogen generation.

Epitaxial highly ordered Sb:SnO2 nanowires grown by the vapor liquid solid mechanism on m-, r- and a-Al2O3.

Epitaxial, highly ordered Sb:SnO2 nanowires were grown by the vapor-liquid-solid mechanism on m-, r- and a-Al2O3 between 700 °C and 1000 °C using metallic Sn and Sb with a mass ratio of Sn/Sb = 0.15 ± 0.05 under a flow of Ar and O2 at 1 ± 0.5 mbar. We find that effective doping and ordering can only be achieved inside this narrow window of growth conditions. The Sb:SnO2 nanowires have the tetragonal rutile crystal structure and are inclined along two mutually perpendicular directions forming a rectangular mesh on m-Al2O3 while those on r-Al2O3 are oriented in one direction. The growth directions do not change by varying the growth temperature between 700 °C and 1000 °C but the carrier density decreased from 8 × 1019 cm-3 to 4 × 1017 cm-3 due to the re-evaporation and limited incorporation of Sb donor impurities in SnO2. The Sb:SnO2 nanowires on r-Al2O3 had an optical transmission of 80% above 800 nm and displayed very long photoluminescence lifetimes of 0.2 ms at 300 K. We show that selective area location growth of highly ordered Sb:SnO2 nanowires is possible by patterning the catalyst which is important for the realization of novel nanoscale devices such as nanowire solar cells.

Streptococcus equi subsp. zooepidemicus meningitis.

A 72-year-old woman was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. The same organism was cultured from her two horses. She denied contact with horses, but had a practice of consuming unpasteurized milk from a cow. The cow was in the same stable as the horses, and the ill woman's son milked the cow.

Infective endocarditis caused by USA300 methicillin-resistant Staphylococcus aureus (MRSA).

We report seven cases of infective endocarditis caused by USA300 methicillin-resistant Staphylococcus aureus (MRSA) at an urban, tertiary care, academic institution. Five strains were community associated and two were healthcare associated. All patients were injection drug users. Staphylococcus aureus isolates were characterised as USA300-type MRSA using pulsed-field gel electrophoresis. Five cases were right-sided endocarditis and two cases were left-sided. The mean length of in-hospital antimicrobial therapy was 23 days and the mean length of total antibiotic therapy was 55 days. Complications included heart failure resulting in valve replacement in one patient as well as death in that patient. As USA300 strains of MRSA continue to increase in prevalence, clinicians must be aware of the increasing spectrum of illness in considering management and prevention strategies.

High-level aminoglycoside-resistant enterococci. Colonization of nursing home and acute care hospital patients.

Enterococci with high-level resistance (HLR) to gentamicin sulfate and other aminoglycosides have emerged as pathogens in recent years. More than half of all current isolates of enterococci at the Ann Arbor (Mich) Veterans Administration (VA) Medical Center are HLR strains. We determined the rate of colonization with HLR enterococci in patients in the acute care hospital, the attached nursing home, and a private nursing home. We also studied the factors related to colonization and the molecular relatedness of strains of HLR enterococci in these settings. In the VA facilities, 47.4% of patients in the nursing home and 36.1% of patients in the acute care hospital were colonized, compared with a 4.3% colonization rate in the private nursing home. Intravenous or Foley catheters and bedridden status were associated with colonization in the acute care setting; the need for advanced nursing care and prior antibiotic therapy were associated with colonization in the nursing home. Environmental surfaces were contaminated with HLR enterococci in both VA settings. Plasmid analysis of HLR strains revealed identity between both patient and environmental strains in the nursing home care unit and the acute care hospital. Nursing home patients, with their high rate of colonization with HLR enterococci and their frequent movement into the acute care hospital, may play a role as a reservoir for subsequent transmission of HLR enterococci.

Electrical, structural, and optical properties of sulfurized Sn-doped In2O 3 nanowires.

Sn-doped In2O3 nanowires have been grown on Si via the vapor-liquid-solid mechanism at 800 °C and then exposed to H2S between 300 to 600 °C. We observe the existence of cubic bixbyite In2O3 and hexagonal SnS2 after processing the Sn:In2O3 nanowires to H2S at 300 °C but also cubic bixbyite In2O3, which remains dominant, and the emergence of rhombohedral In2(SO4)3 at 400 °C. The resultant nanowires maintain their metallic-like conductivity, and exhibit photoluminescence at 3.4 eV corresponding to band edge emission from In2O3. In contrast, Sn:In2O3 nanowires grown on glass at 500 °C can be treated under H2S only below 200 °C which is important for the fabrication of Cu2S/Sn:In2O3 core-shell p-n junctions on low-cost transparent substrates such as glass suitable for quantum dot-sensitized solar cells.

Nosocomial acquisition of Candida parapsilosis: an epidemiologic study.

OBJECTIVE: The purpose of this study was to determine aspects of the epidemiology of nosocomial infection due to Candida parapsilosis. Candida species are important nosocomial pathogens; however, little epidemiologic information is available. PATIENTS AND METHODS: We prospectively cultured specimens from 98 patients admitted to the bone marrow transplant unit and a medicine intensive care unit (ICU) of a tertiary care hospital. Specimens from hands of personnel and environmental surfaces were also cultured. Environmental cultures were done before patients were admitted to a studied unit. Restriction enzyme analysis (REA) of chromosomal DNA was used as a typing system to determine the relatedness of strains. RESULTS: C. parapsilosis was identified from five patients, six hand cultures from four hospital staff, and two environmental surfaces. All five patients had negative initial cultures and acquired C. parapsilosis after admission to the study unit. There were no significant differences between patients and control subjects in age, underlying disease, immunosuppressive therapy, and instrumentation. The duration of antibiotic therapy (median: 32.8 versus 11.8 days, p = 0.05) and the duration in the unit (means: 30.1 versus 16.1 days, p = 0.048) was longer in patients than in controls. No common source was identified. REA revealed three strain types; however, one strain type was identical in four patients, three staff members, and two environmental surfaces. CONCLUSION: These results suggest exogenous acquisition of C. parapsilosis. Based upon isolation of identical patient strains of C. parapsilosis from inanimate surfaces before patients were admitted to a study unit, there is evidence that the organism may have been acquired from the hospital environment. The principal mechanism of transmission was probably indirect contact via the hands of hospital personnel.

Association of contaminated gloves with transmission of Acinetobacter calcoaceticus var. anitratus in an intensive care unit.

PURPOSE: Acinetobacter calcoaceticus var. anitratus is an important nosocomial pathogen that has been associated with environmental reservoirs. An increased isolation rate of A. anitratus in our intensive care units (ICUs), from 0.03% (two of 7,800) to 0.5% (seven of 1,300) (p less than 0.00003), prompted an investigation. PATIENTS, METHODS, AND RESULTS: Ten patients were admitted to the surgical ICU and nine to the medical ICU during the outbreak period (late December 1987 to January 1988). Controls were all patients on the units who were not infected or colonized with the transmitted strain of A. anitratus. Three patients had A. anitratus pneumonia. A throat culture prevalence survey demonstrated three patients colonized with A. anitratus. Cases were placed in a cohort and symptomatic cases treated. An epidemiologic investigation was conducted to identify reservoirs and modes of transmission. Latex gloves were being used for universal precautions without routine changing of gloves between patients. Environmental sources culture-positive for A. antitratus included a small volume medication nebulizer and gloves in use for patient care. Plasmid typing showed that plasmid profiles of isolates from two symptomatic patients, two colonized patients, the nebulizer, and the gloves were identical. Other A. anitratus ICU isolates had distinct plasmid profiles. All patients with the transmitted strain had been in the surgical ICU. The need for changing gloves between patients and contaminated body sites was reinforced. CONCLUSION: Gloves, used incorrectly for universal precautions, may potentially transmit A. anitratus.

Invasive Candida guilliermondii infection: in vitro susceptibility studies and molecular analysis.

Candida guilliermondii is rarely isolated from humans. We describe a case of disseminated C. guilliermondii with associated purulent pericarditis, despite high-dose amphotericin B (AmB), in a 19-year-old female with aplastic anemia who underwent BMT. In vitro susceptibility studies of the 13 clinical isolates, two control strains and one environmental isolate revealed a minimum inhibitory concentration (MIC) range of (0.19-1.56 micrograms/ml) for AmB and (1.25-10 micrograms/ml) for fluconazole. Pulsed-field gradient gel electrophoresis was performed to evaluate possible similarities between strains. This case is significant for several reasons, the high degree and prolonged duration of fungemia despite high-dose AmB and concomitant flucytosine, the change in in vitro susceptibility during therapy, the initial misidentification of the yeast isolate, and the invasiveness of the organism. The poor response to therapy may have been due to the severe and sustained neutropenia and the high MICs of C. guilliermondii to AmB.

Control of endemic glycopeptide-resistant enterococci.

OBJECTIVE: To evaluate the epidemiology of, and control measures for, vancomycin-resistant Enterococcus (VRE) in a renal unit. DESIGN: A 3-month, prospective, prevalence culture survey of patients on a 24-bed renal unit. SETTING: A 975-bed community teaching hospital. PATIENTS: Patients admitted to the renal unit over a 3-month period. Patients identified with VRE were each matched with four patients without VRE isolated over the study period. INTERVENTIONS/CONTROL MEASURES: Resistant-organism barrier precautions. To eradicate carriage of VRE, two patients with VRE stool colonization were treated with 5 days of oral doxycycline (100 mg twice per day) and rifampin (300 mg/day). RESULTS: Seven patients with VRE (8 isolates) were identified. Five isolates were Enterococcus faecium (vancomycin MIC = 16 to 256 micrograms/mL), two were Enterococcus faecalis (MICs = 16 and 124 micrograms/mL), and one was Enterococcus gallinarum (MIC = 8.0 micrograms/mL). Eradication of carriage with VRE was accomplished in two patients treated with doxycycline and rifampin. In the final 30 days of the culture survey and at 9 months, there were no further patients with VRE identified. CONCLUSIONS: Resistant-organism precautions and elimination of patient carriage may be useful measures for controlling the spread of low-prevalence endemic vancomycin-resistant Enterococcus.

Comparative in vitro activity of antiseptics and disinfectants versus clinical isolates of Candida species.

OBJECTIVE: To evaluate the in vitro activity of antiseptics and detergents against Candida. DESIGN: One strain each of Candida albicans, Candida tropicalis, Candida lusitaniae, Candida parapsilosis, Candida kefyr, Candida glabrata, and an American Type Culture Collection strain of Escherichia coli (control) were studied. Clinical isolates were obtained from patients in a bone marrow unit of a large tertiary hospital. Antiseptic and disinfectant agents studied were used in the hospital where isolates were identified for cleaning of inanimate surfaces or hand washing. In vitro susceptibility was determined using a broth macrodilution method with exposure times to antiseptic or disinfectant agent of 15 seconds to 4 minutes and concentrations of agents that ranged from undiluted to 1:10,000 dilution. SETTING: A 900-bed teaching hospital. RESULTS: Of disinfectants tested, Vestal and Sparquat inhibited growth of all species at dilutions of < or = 1:100 at all contact times for all species. Clorox showed inhibition of growth at 1:100 dilution after 30 seconds of contact time for all isolates. Of antiseptics studied, Hibiclens inhibited growth of all species except C tropicalis at dilutions of < or = 1:100 at all contact times and for C tropicalis after 60 seconds. Clinidine inhibited growth of all species at dilutions of < or = 1:100 at all contact times for all species with the exception of Cglabrata and C tropicalis, which grew at the undiluted concentration. Ultradex failed to demonstrate killing of any species for any dilutions tested. CONCLUSIONS: The results of this study show varying degrees of in vitro inhibition of growth by a variety of antiseptics and disinfectants against clinical isolates of Candida species from hospitalized patients.

Enterococcal infections: an increasing problem in hospitalized patients.

We studied 157 episodes of infection or colonization with enterococci in 122 patients over a six-month period. One hundred twelve episodes (71.3%) occurred in patients over age 60 years. The most common sites for isolation of enterococci were the urinary tract, and bone and soft tissue. Nosocomial acquisition of enterococci occurred in 74.7% of all infections, and an additional 21% of episodes occurred in patients who had been transferred from another hospital or were regularly seen in the clinic. The overall mortality was 19.6%; 71.4% of those with bacteremia died. Enterococci appear to be significant pathogens, especially in older men in veterans' acute care hospitals and nursing home care units.

Epidemiological study of hospital-acquired infection with vancomycin-resistant Enterococcus faecium: possible transmission by an electronic ear-probe thermometer.

Clonal spread of vancomycin-resistant Enterococcus faecium among seven patients on one ward of a community teaching hospital was identified by contour-clamped homogeneous electric-field gel electrophoresis. Environmental cultures isolated the same strain from the handle of a shared electronic ear-probe thermometer. Cross-contamination of the clonal strain between two geographically separate units on this ward, sharing equipment but not personnel, suggests the possibility of an environmental source.

Controlling vancomycin-resistant enterococci.

After controlling an epidemic of vanB-type vancomycin-resistant Enterococcus faecium (VRE), we contained a subsequent vanA E faecium outbreak by using prospective laboratory-based surveillance, placing patients with VRE in private rooms, requiring the use of both gowns and gloves by all personnel entering the patients' rooms, and conducting prevalence surveys of patients on affected wards.

Colonization with vancomycin-resistant Enterococcus faecium: comparison of a long-term-care unit with an acute-care hospital.

OBJECTIVE: To compare the epidemiology of vancomycin-resistant Enterococcus faecium (VRE) in a long-term-care unit and an acute-care hospital. DESIGN: Point-prevalence surveys for VRE rectal colonization of patients were carried out over a 21-month period in patients in a long-term-care unit and an acute-care hospital (medical ward and intensive-care units). The environment and hands of healthcare workers also were sampled for VRE. Contour-clamped homogeneous electric field (CHEF) electrophoresis was used to evaluate possible transmission among roommates and the relatedness of patient strains to those in the environment and on the hands of healthcare workers. SETTING: A 200-bed Veterans Affairs Medical Center with an attached 90-bed long-term-care unit. RESULTS: From December 1994 to January 1996, rectal VRE colonization of patients in the long-term-care unit increased significantly from 9% to 22%. In contrast, patients on the medical ward rarely were colonized after the first survey in December 1994, and only two intensive-care-unit patients were found to be colonized during the four surveys. The environment was contaminated persistently in the long-term-care unit. In the four surveys, carriage of VRE on hands of healthcare workers varied from 13% to 41%; 65% of healthcare workers with VRE found on their hands worked in the long-term-care unit. Seven different strains were identified by CHEF typing. Although the initial survey found only vanA strains, subsequent surveys showed vanB strains also were present. CONCLUSIONS: Residents of a long-term-care unit frequently were colonized with VRE, but infections were uncommon in this population. The environment of the long-term-care unit was contaminated with VRE, and VRE was found frequently on the hands of healthcare workers in this unit. Both vanA and vanB genotypes were found in this setting.

Risk factors for enterococcal urinary tract infection and colonization in a rehabilitation facility.

BACKGROUND: We attempted to define the risk factors for urinary tract acquisition of enterococcus in a 155-bed rehabilitation facility in Southeastern Michigan by performing a prospective, case-controlled observational study. METHODS: All cases were identified from daily review of microbiologic records of urine culture results. All urinary isolates of enterococcus species, whether representing infection or colonization, were saved on agar plates for subsequent pulsed-field gel electrophoresis. Thirty-five percent of urinary tract isolates were due to enterococcal species compared with 5% to 15% in adjacent acute-care facilities. A control was defined as the next patient with a nonenterococcal urinary isolate. RESULTS: No differences were found between cases and controls with respect to age, sex, admitting diagnosis, voiding habits, symptoms, laboratory values, geographic location, caregivers, or urinary infection versus colonization. CONCLUSIONS: Prior antibiotic use was more frequent in the patients colonized or infected with enterococcal isolates (78% vs 41%). No evidence was found for a single clone of enterococcal isolates in our facility by DNA analysis, suggesting that the acquisition of enterococcus in the urinary tract was endogenous.