Prevalence and duration of asymptomatic Clostridium difficile carriage among healthy subjects in Pittsburgh, Pennsylvania.

Previous studies suggested that 7 to 15% of healthy adults are colonized with toxigenic Clostridium difficile. To investigate the epidemiology, genetic diversity, and duration of C. difficile colonization in asymptomatic persons, we recruited healthy adults from the general population in Allegheny County, Pennsylvania. Participants provided epidemiological and dietary intake data and submitted stool specimens. The presence of C. difficile in stool specimens was determined by anaerobic culture. Stool specimens yielding C. difficile underwent nucleic acid testing of the tcdA gene segment with a commercial assay; tcdC genotyping was performed on C. difficile isolates. Subjects positive for C. difficile by toxigenic anaerobic culture were asked to submit additional specimens. One hundred six (81%) of 130 subjects submitted specimens, and 7 (6.6%) of those subjects were colonized with C. difficile. Seven distinct tcdC genotypes were observed among the 7 C. difficile-colonized individuals, including tcdC genotype 20, which has been found in uncooked ground pork in this region. Two (33%) out of 6 C. difficile-colonized subjects who submitted additional specimens tested positive for identical C. difficile strains on successive occasions, 1 month apart. The prevalence of C. difficile carriage in this healthy cohort is concordant with prior estimates. C. difficile-colonized individuals may be important reservoirs for C. difficile and may falsely test positive for infections due to C. difficile when evaluated for community-acquired diarrhea caused by other enteric pathogens.

Screening for Acinetobacter baumannii colonization by use of sponges.

There is currently no consensus method for the active screening of Acinetobacter baumannii. The use of swabs to culture nostrils, pharynx, and skin surface of various anatomical sites is known to yield less-than-optimal sensitivity. In the present study, we sought to determine whether the use of sterile sponges to sample large areas of the skin would improve the sensitivity of the detection of A. baumannii colonization. Forty-six patients known to be colonized with A. baumannii, defined by a positive clinical culture for this organism as defined by resistance to more than two classes of antimicrobials, participated in the study. The screening sites included the forehead, nostrils, buccal mucosa, axilla, antecubital fossa, groin, and toe webs with separate rayon swabs and the forehead, upper arm, and thigh with separate sponges. Modified Leeds Acinetobacter medium (mLAM) agar plates that contained vancomycin and either aztreonam or ceftazidime were used as the selective medium. An enrichment culture grown overnight substantially increased the sensitivity for most sites. The sensitivity ranged between 69.6 and 82.6% for individual sponge sites and 21.7 to 52.2% for individual swab sites when mLAM plates with ceftazidime were inoculated after a 24-h enrichment period. The sponge and swab sites with the best sensitivity were the leg and the buccal mucosa, respectively (82.6% and 52.2%; P = 0.003). The combined sensitivity for the upper arm and leg with a sponge was 89.1%. The novel screening method using sterile sponges was easy to perform and achieved excellent sensitivity for the detection of A. baumannii colonization.

Needles in a haystack: Extremely rare invasive fungal infections reported in FungiScopeⓇ-Global Registry for Emerging Fungal Infections.

OBJECTIVES: Emerging invasive fungal infections (IFI) have become a notable challenge. Apart from the more frequently described fusariosis, lomentosporiosis, mucormycosis, scedosporiosis, and certain dematiaceae or yeasts, little is known about extremely rare IFI. METHODS: Extremely rare IFI collected in the FungiScopeⓇ registry were grouped as Dematiaceae, Hypocreales, Saccharomycetales, Eurotiales, Dermatomycetes, Agaricales, and Mucorales. RESULTS: Between 2003 and June 2019, 186 extremely rare IFI were documented in FungiScopeⓇ. Dematiaceae (35.5%), Hypocreales (23.1%), Mucorales (11.8%), and Saccharomycetales (11.3%) caused most IFI. Most patients had an underlying malignancy (38.7%) with acute leukemia accounting for 50% of cancers. Dissemination was observed in 26.9% of the patients. Complete or partial clinical response rate was 68.3%, being highest in Eurotiales (82.4%) and in Agaricales (80.0%). Overall mortality rate was 29.3%, ranging from 11.8% in Eurotiales to 50.0% in Mucorales. CONCLUSIONS: Physicians are confronted with a complex variety of fungal pathogens, for which treatment recommendations are lacking and successful outcome might be incidental. Through an international consortium of physicians and scientists, these cases of extremely rare IFI can be collected to further investigate their epidemiology and eventually identify effective treatment regimens.

Treatment of resistant influenza virus infection in a hospitalized patient with cystic fibrosis with DAS181, a host-directed antiviral.

We report a cystic fibrosis patient infected with influenza 2009H1N1 who had persistent viral shedding and clinical deterioration despite prolonged treatment with oseltamivir and zanamivir. The patient was diagnosed with H275Y neuraminidase inhibitor resistant influenza during treatment, thus was treated for 10 days with DAS181, an investigational host-directed inhaled sialidase fusion protein. Viral clearance occurred after 5 days of therapy and the patient became eligible for lung transplantation. Although the patient succumbed prior to receiving a transplant, this case exemplifies the potential utility of a host-directed approach against influenza which has potential to become resistant to neuraminidase inhibitors.

Screening for methicillin-resistant Staphylococcus aureus colonization using sponges.

OBJECTIVE Nasal swab culture is the standard method for identifying methicillin-resistant Staphylococcus aureus (MRSA) carriers. However, this method is known to miss a substantial portion of those carrying MRSA elsewhere. We hypothesized that the additional use of a sponge to collect skin culture samples would significantly improve the sensitivity of MRSA detection. DESIGN Hospitalized patients with recent MRSA infection were enrolled and underwent MRSA screening of the forehead, nostrils, pharynx, axilla, and groin with separate swabs and the forehead, axilla, and groin with separate sponges. Staphylococcal cassette chromosome mec (SCCmec) typing was conducted by polymerase chain reaction (PCR). PATIENTS A total of 105 MRSA patients were included in the study. RESULTS At least 1 specimen from 56.2% of the patients grew MRSA. Among patients with at least 1 positive specimen, the detection sensitivities were 79.7% for the swabs and 64.4% for the sponges. Notably, 86.4% were detected by a combination of sponges and nasal swab, and 72.9% were detected by a combination of pharyngeal and nasal swabs, whereas only 50.9% were detected by nasal swab alone (P<0.0001 and P=0.0003, respectively). Most isolates had SCCmec type II (59.9%) and IV (35.7%). No correlation was observed between the SCCmec types and collection sites. CONCLUSION Screening using a sponge significantly improves MRSA detection when used in addition to screening with the standard nasal swab.

Magnetic resonance tagging and echocardiographic response to dobutamine and functional improvement after reperfused myocardial infarction.

OBJECTIVE: Our objective was to compare the qualitative response to low-dose dobutamine by echocardiography (DSE) with the quantitative response of magnetic resonance myocardial tagging (DMRT) in the prediction and evaluation of functional improvement after reperfused myocardial infarction (MI). METHODS: Twenty-two patients with a reperfused first MI (aged 51 +/- 2 years, 20 male, 13 anterior MI) were studied. On day 3 +/- 1 after MI, patients underwent both DSE and DMRT at baseline and during infusion of 5 microg/kg/min and 10 microg/kg/min of dobutamine. The patients returned at week 8 +/- 1 for follow-up echocardiogram and MRT at rest. Two experienced observers interpreted the DSE for the presence of contractile reserve and functional improvement in dysfunctional segments. By DMRT, a 5% increase in percent intramyocardial circumferential shortening at peak response to dobutamine was defined as evidence of contractile reserve. Functional improvement by echocardiography was defined as the gold standard. RESULTS: Ejection fraction improved from 46% +/- 10% at week 1 to 51% +/- 12% at week 8 (P <.001) in the patients. Sixty-seven transmural segments with baseline dysfunction matched between imaging modalities by location were studied. For 51 (76%) of the segments, echocardiography and MR tagging were concordant in the assessment of functional improvement (kappa value 0.52). Twenty-nine segments (43%) demonstrated improvement by echocardiography, whereas 33 segments (49%) improved by MR tagging. With improvement of function by echocardiography as gold standard, the sensitivity and specificity of DMRT for prediction of functional improvement was 86% and 69%, respectively, with an overall accuracy of 76%. The sensitivity, specificity, and accuracy of DSE was 86%, 87%, and 85%, respectively. Overall accuracy was similar between techniques. CONCLUSIONS: Both DSMRT and DSE are sensitive and accurate techniques for predicting functional improvement after reperfused MI.

Risk factors and outcome of extended-spectrum ß-lactamase-producing Enterobacter cloacae bloodstream infections.

Enterobacter cloacae is a major nosocomial pathogen that causes serious infections, including bloodstream infections (BSIs). The clinical significance of extended-spectrum ß-lactamase (ESBL) production in E. cloacae is not well established. A multicentre, retrospective, cohort study was conducted to identify clinical characteristics of patients with E. cloacae BSI. ESBL production was confirmed by genotypic methods. A total of 159 patients with E. cloacae BSI were identified at three medical centres in north-eastern USA. Amongst them, 16 patients (10.1%) harboured ESBL-producing E. cloacae. Independent risk factors for ESBL production included admission from a nursing home, the presence of a gastrostomy tube and history of transplant. For the outcome analysis, 15 consecutive patients who had ESBL-producing E. cloacae BSI prior to the study were included. Amongst the 31 patients with ESBL-producing E. cloacae, 8, 9, 4 and 2 patients received a carbapenem, cefepime, piperacillin/tazobactam and ciprofloxacin, respectively, as initial therapy. All patients who received a carbapenem (n=8) were alive at 28 days, whereas 7 (38.9%) of 18 patients who received a non-carbapenem antibiotic did not survive (P=0.06). Clinical failure at 96 h was observed in 2 (25.0%) of 8 patients who received a carbapenem and in 14 (77.8%) of 18 patients who received a non-carbapenem antibiotic (P=0.03). Pulsed-field gel electrophoresis showed little clonality amongst the study isolates. The majority of isolates produced SHV-type ESBL, whereas two isolates produced CTX-M-type ESBL. Initial therapy with a carbapenem appears to be associated with improved clinical outcome in BSI due to ESBL-producing E. cloacae.

Intrapulmonary disposition of amphotericin B after aerosolized delivery of amphotericin B lipid complex (Abelcet; ABLC) in lung transplant recipients.

BACKGROUND: Inhaled amphotericin preparations have been used for prophylaxis against invasive aspergillosis in lung transplant recipients. However, no published data exist regarding the pharmacokinetic profile of amphotericin B lipid complex in lung transplant recipients. METHODS: We prospectively determined the concentrations of amphotericin B in the epithelial lining fluid (ELF) and plasma after aerosolized nebulization (AeroEclipse), of amphotericin B lipid complex at 1 mg/kg every 24 hr for 4 days in 35 lung transplant recipients. One brochoalveolar lavage sample and a simultaneous blood sample were collected at various time points after the fourth dose from each subject. High-performance liquid chromatography and high-performance liquid chromatography-MS-MS were used to measure amphotericin B. RESULTS: Concentrations of amphotericin B in ELF (median, 25-75 IQR) were at 4 hr (n=5) 7.20 µg/mL (1.3-17.6), 24 hr (n=6) 8.26 µg/mL (3.9-82.7), 48 hr (n=5) 2.15 µg/mL (1.4-5.5), 72 hr (n=4) 1.25 µg/mL (0.75-5.5), 96 hr (n=6) 0.86 µg/mL (0.55-1.4), 120 hr (n=4) 1.04 µg/mL (0.44-1.6), 144 hr (n=1), 4.25 µg/mL, 168 hr (n=3) 1.14 µg/mL, and 192 hr (n=1) 1 µg/mL. The plasma concentration of the drug remained below 0.08 µg/mL at all time points. During the study, the side effects noted included wheezing, coughing, and 12% decline in forced expiratory volume in 1 sec. CONCLUSIONS: We conclude that administration through aerosolized nebulization of amphotericin B lipid complex every 24 hr for 4 days in lung transplant recipients achieved amphotericin B concentrations in ELF above minimum inhibitory concentration of the Aspergillus nearly at 168 hr after the last inhaled dose and is well tolerated.

Experience with immune monitoring in lung transplant recipients: correlation of low immune function with infection.

BACKGROUND: Lung transplants, in particular, have the highest rate of infections among solid organ transplant recipients. However, there is no existing objective measure to predict the development of infections. We report the correlation between Cylex ImmuKnow (ng/mL ATP) values and various infectious syndromes in a large prospective cohort of lung transplant recipients. METHODS: We followed up 175 lung transplants that developed 129 infectious episodes. Multiple logistic regression analysis was performed; generalized estimating equations were used to determine the odds ratio for infections. RESULTS: The median ImmuKnow values in cytomegalovirus disease (49.3 ng/mL ATP), viral infection (70 ng/mL ATP), and bacterial pneumonia (92 ng/mL ATP) were significantly different from stable state (174.8 ng/mL ATP). The median ImmuKnow values of fungal disease (85 ng/mL ATP) and tracheobronchitis (123 ng/mL ATP) had a tendency to be lower than stable state (P=0.10), whereas patients with fungal colonization had comparable ImmunKnow values (167 vs. 174.8 ng/mL ATP). Of the patients colonized with fungus who subsequently developed fungal disease within 100 days, the median value of ImmuKnow was significantly lower than in those who did not develop fungal disease (22.5 vs. 183.5 ng/mL ATP; P<0.0001). Generalized estimating equation regression analysis showed ImmuKnow values less than or equal to 100 ng/mL ATP to be an independent predictor of infections (odds ratio 2.81). CONCLUSIONS: Cylex ImmuKnow assay monitoring has the potential to identify the patients at risk of developing infection and those colonized with fungus that are at risk of developing disease.