DIFFERENCES IN RESTING-SITE PREFERENCE IN TWO COEXISTING LAND SNAILS, ARIANTA ARBUSTORUM AND ARIANTA CHAMAELEON (HELICIDAE), ON ALPINE SLOPES

Resting-site preference and patterns of spatial distribution were examined in the sympatric land snails Arianta arbustorum and A. chamaeleon on two opposite slopes in the south-eastern Alps, Austria. The two slopes did not differ in proportion of A. arbustorum and A. chamaeleon (74.4% vs. 25.6% on the NNE-exposed slope and 68.3% vs. 31.7% on the SSW-exposed slope). Individuals of both species showed aggregated dispersion patterns. The nearest-neighbour method indicated that in both species snail aggregations predominantly consisted either of A. arbustorum or A. chamaeleon on the NNE-exposed slope with a mosaic of rocks and distinct patches of different plants. On the SSW-exposed slope, which was less variable in vegetation cover, snail aggregations consisted of conspecific and hetero-specific individuals. Juvenile and adult A. arbustorum preferred to rest attached to leaves of Adenostyles alliariae, but avoided rock surfaces and patches of grass on the NNE-exposed slope. In contrast, juvenile and adult A. chamaeleon preferentially rested on rock surfaces, and also avoided grass patches. Juvenile and adult A. chamaeleon did not differ in resting-site preference, whereas small differences in resting sites were observed between juvenile and adult A. arbustorum. Differences in resting-site preference is one way of niche differentiation which may allow individuals of the two Arianta species to coexis

Intestinal Infection Due to Enteroaggregative Eschevichia coli among Human Immunodeficiency Virus—Infected Persons

To investigate the pathogenic role of enteroaggregative Escherichia coli (EAggEC) among human immunodeficiency virus—infected persons, 111 outpatients with and 68 without diarrhea were evaluated. Examination of stool samples included the HeLa cell adherence assay and an EAggEC polymerase chain reaction (PCR) assay using primers complementary for the plasmid locus CVD432. The pCVD432 genotype, adherence phenotype, and patient characteristics were correlated with occurrence of diarrhea by multivariate analyses. EAggEC PCR and adherence assays were positive in 7 (6%) and 24 (22%) patients with diarrhea and in 1 (1%) and 21 (31%) asymptomatic control patients, respectively. Clinical manifestations associated with EAggEC PCR-positive isolates were nonspecific; EAggEC infections were independent of CD4 lymphocyte counts. Of the pCVD432 genotype, 5 (71%) of 7 were resistant to cotrimoxazole and ampicillin, and 1 strain was resistant to ciprofloxacin. Overall, pCVD432 PCR-positive E. coli was the most prevalent intestinal organism associated with diarrhea. The adherence assay results did not correlate with diarrhe

Human Immunodeficiency Virus Type 1 p24 Concentration Measured by Boosted ELISA of Heat-Denatured Plasma Correlates with Decline in CD4 Cells, Progression to AIDS, and Survival: Comparison with Viral RNA Measurement

Human immunodeficiency virus type 1 (HIV-1) RNA and p24 antigen concentrations were determined in plasma samples from 169 chronically infected patients (median CD4 cell count, 140 cells/μL; range, 0-1500 cells/μL). p24 quantification involved heat-mediated immune complex dissociation and tyramide signal amplification—boosted ELISA, which has a diagnostic sensitivity similar to that of RNA quantification by a commercial polymerase chain reaction kit. In Cox's proportional hazard models adjusted for CD4 cell count, both RNA (P < .005) and p24 (P = .043) levels were significant predictors of progression to AIDS. Measurement of p24 was superior to measurement of RNA in the model for survival (P = .032 vs. P = .19). p24 level was a significant predictor of CD4 cell decline in models adjusted for CD4 cell counts and was superior or equivalent to RNA level, depending on the group analyzed. Stratification by CD4 cell counts at baseline showed that the superiority of p24 measurement was more pronounced at lower levels of CD4 cells (<200/μL). p24 level may be of interest as a simple and inexpensive predictive marker of disease progressio

Stratification of cumulative antibiograms in hospitals for hospital unit, specimen type, isolate sequence and duration of hospital stay

Background Empirical antibiotic therapy is based on patients' characteristics and antimicrobial susceptibility data. Hospital-wide cumulative antibiograms may not sufficiently support informed decision-making for optimal treatment of hospitalized patients. Methods We studied different approaches to analysing antimicrobial susceptibility rates (SRs) of all diagnostic bacterial isolates collected from patients hospitalized between July 2005 and June 2007 at the University Hospital in Zurich, Switzerland. We compared stratification for unit-specific, specimen type-specific (blood, urinary, respiratory versus all specimens) and isolate sequence-specific (first, follow-up versus all isolates) data with hospital-wide cumulative antibiograms, and studied changes of mean SR during the course of hospitalization. Results A total of 16 281 isolates (7965 first, 1201 follow-up and 7115 repeat isolates) were tested. We found relevant differences in SRs across different hospital departments. Mean SRs of Escherichia coli to ciprofloxacin ranged between 64.5% and 95.1% in various departments, and mean SRs of Pseudomonas aeruginosa to imipenem and meropenem ranged from 54.2% to 100% and 80.4% to 100%, respectively. Compared with hospital cumulative antibiograms, lower SRs were observed in intensive care unit specimens, follow-up isolates and isolates causing nosocomial infections (except for Staphylococcus aureus). Decreasing SRs were observed in first isolates of coagulase-negative staphylococci with increasing interval between hospital admission and specimen collection. Isolates from different anatomical sites showed variations in SRs. Conclusions We recommend the reporting of unit-specific rather than hospital-wide cumulative antibiograms. Decreasing antimicrobial susceptibility during hospitalization and variations in SRs in isolates from different anatomical sites should be taken into account when selecting empirical antibiotic treatmen

Correlation between case mix index and antibiotic use in hospitals

Background To compare the quantitative antibiotic use between hospitals or hospital units and to explore differences, adjustment for severity of illness of hospitalized patients is essential. The case mix index (CMI) is an economic surrogate marker (i.e. the total cost weights of all inpatients per a defined time period divided by the number of admissions) to describe the average patients' morbidity of individual hospitals. We aimed to investigate the correlation between CMI and hospital antibiotic use. Methods We used weighted linear regression analysis to evaluate the correlation between in-hospital antibiotic use in 2006 and CMI of 18 departments of the tertiary care University Hospital Zurich and of 10 primary and 2 secondary acute care hospitals in the Canton of Zurich in Switzerland. Results Antibiotic use varied substantially between different departments of the university hospital [defined daily doses (DDD)/100 bed-days, 68.04; range, 20.97-323.37] and between primary and secondary care hospitals (range of DDD/100 bed-days, 15.45-57.05). Antibiotic use of university hospital departments and the different hospitals, respectively, correlated with CMI when calculated in DDD/100 bed-days [coefficient of determination (R2), 0.57 (P = 0.0002) and 0.46 (P = 0.0065)], as well as when calculated in DDD/100 admissions [R2, 0.48 (P = 0.0008) and 0.85 (P < 0.0001), respectively]. Conclusions Antibiotic use correlated with CMI across various specialties of a university hospital and across different acute care hospitals. For benchmarking antibiotic use within and across hospitals, adjustment for CMI may be a useful tool in order to take into account the differences in hospital category and patients' morbiditie

Outcomes of Antiretroviral Therapy in the Swiss HIV Cohort Study: Latent Class Analysis

An in-depth understanding of the different groups that make up the HIV-infected population should inform prevention and care. Using latent class analysis (LCA) we identified seven groups with similar socio-demographic and behavioral characteristics at enrolment in the Swiss HIV Cohort Study: older gay men, younger gay men, older heterosexual men, injection drug users, single migrants, migrant women in partnerships and heterosexual men and women. Outcomes of combination antiretroviral therapy (ART) were analyzed in 1,633 patients starting ART. Compared to older gay men, the probability of a virologic response to ART was reduced in single migrants, in older heterosexual men and in IDUs. Loss to follow-up was higher in single migrants and IDUs, and mortality was increased in older heterosexual men and IDUs. Socio-behavioral groups identified by LCA allow insights above what can be gleaned from traditional transmission groups, and may identify patients who could benefit from targeted intervention

Morbidity and Aging in HIV-Infected Persons: The Swiss HIV Cohort Study

Comorbid diseases, such as myocardial infarction, stroke, diabetes mellitus, bone fractures without adequate trauma, osteoporosis, and non-AIDS-defining malignancies, among HIV-infected individuals are age-related. Consequently, multimorbidity will become an important issue in care of the aging HIV-infected populatio