Lack of microbiological awareness on the ward as a key factor for inappropriate use of anti-infectives: results of a point prevalence study and user satisfaction survey in a large university hospital in Austria.

PURPOSE: Although diagnostic stewardship issues in clinical microbiology harbor an optimization potential for anti-infective consumption, they are only marginally addressed in antimicrobial stewardship (AMS) programs. As part of an AMS point prevalence (PPS) survey we therefore aimed to gain a more dynamic view on the microbiological awareness within therapeutic regimens. By examining whether initial microbiological sampling was performed and in which way microbiological results were incorporated into further treatment considerations we sought to find out to what extent these points determine the appropriateness of treatment regimens. METHODS: PPS was performed at the University Hospital Salzburg (1524 beds) in May 2021. Relevant data was determined from the patient charts and the appropriateness of anti-infective use was assessed using predefined quality indicators. Six months after the PPS, a questionnaire was administered to clinicians to obtain information on the use of microbiological findings and their relevance in the clinic. RESULTS: Lack of microbiological awareness in the clinical setting proved to be the key reason for an overall inadequate use of anti-infectives (35.4% of cases rated as inadequate), ahead of the aspects of dose (24.1%), empirical therapy (20.3%) and treatment duration (20.2%). This was particularly the case for broad-acting agents and was most evident in urinary tract infections, skin and soft tissue infections, and pneumonia. The results of the questionnaire indicate a discrepancy between the physicians surveyed and the routine clinical setting. CONCLUSION: A high potential in improving the use of anti-infectives in hospitals seems to lie in a strong emphasis on microbiological diagnostic stewardship measures.

Immunomodulatory Aspects of Therapeutic Plasma Exchange in Neurological Disorders-A Pilot Study.

Therapeutic plasma exchange (TPE) is used for drug-resistant neuroimmunological disorders, but its mechanism of action remains poorly understood. We therefore prospectively explored changes in soluble, humoral, and cellular immune components associated with TPE. We included ten patients with neurological autoimmune disorders that underwent TPE and assessed a panel of clinically relevant pathogen-specific antibodies, total serum immunoglobulin (Ig) levels, interleukin-6 (IL-6, pg/mL), C-reactive protein (CRP, mg/dL), procalcitonin (PCT, µg/L) and major lymphocyte subpopulations (cells/µL). Blood was collected prior to TPE (pre-TPE, baseline), immediately after TPE (post-TPE), as well as five weeks (follow-up1) and 130 days (follow-up2) following TPE. Pathogen-specific antibody levels were reduced by -86% (p < 0.05) post-TPE and recovered to 55% (follow-up1) and 101% (follow-up2). Ig subclasses were reduced by -70-89% (p < 0.0001) post-TPE with subsequent complete (IgM/IgA) and incomplete (IgG) recovery throughout the follow-ups. Mean IL-6 and CRP concentrations increased by a factor of 3-4 at post-TPE (p > 0.05) while PCT remained unaffected. We found no alterations in B- and T-cell populations. No adverse events related to TPE occurred. TPE induced a profound but transient reduction in circulating antibodies, while the investigated soluble immune components were not washed out. Future studies should explore the effects of TPE on particular cytokines and assess inflammatory lymphocyte lineages to illuminate the mode of action of TPE beyond autoantibody removal.

The Antimicrobial Resistance (AMR) Rates of Uropathogens in a Rural Western African Area-A Retrospective Single-Center Study from Kpando, Ghana.

Little is known about the antimicrobial resistance (AMR) status of uropathogens in Western Africa. We performed a retrospective evaluation of urine cultures collected from the rural Margret Marquart Catholic Hospital, Kpando, Ghana during the time period from October 2019−December 2021. Urine samples from 348 patients (median age 40 years, 52.6% male) were examined. Of these, 125 (35.9%) showed either fungal or bacterial growth, including Escherichia coli in 48 (38.4%), Candida species (spp.) in 29 (23.2%), Klebsiella spp. in 27 (21.6%), Proteus spp. in 12 (9.6%), Citrobacter spp. in 10 (8.0%), Salmonella spp. in 4 (3.2%), Staphylococcus spp. in 3 (2.4%), and Pseudomonas spp. in 2 (1.6%) cases. Two bacterial spp. were detected in 7 samples (5.6%). Antibiotic susceptibility testing showed resistance to a mean 8.6 out of 11 tested antibiotics per patient. Significant predictors (p < 0.05) of bacterial growth were age (OR 1.03), female sex (OR 3.84), and the number of pus cells (OR 1.05) and epithelial cells (OR 1.07) in urine microscopy. We observed an alarmingly high AMR rate among the uropathogens detected, even to reserve antibiotics. A similar resistance profile can be expected in West African patients living in high-income countries. These observations warrant the implementation of restrictive antibiotic protocols, together with the expansion of urine culture testing capacities, improvement of documentation and reporting of AMR rates, and continued research and development of new antibiotic therapies in order to stem the progression of AMR in this West African region.

SARS-CoV-2 IgG Levels Allow Predicting the Optimal Time Span of Convalescent Plasma Donor Suitability.

Convalescent plasma (CP) has been in use for the treatment of numerous infectious diseases for more than a century, recently also for coronavirus disease 2019 (COVID-19). A major challenge for this treatment is identifying suitable donors with sufficient levels of functional antibodies and to determine the optimal time span for CP donation. In this retrospective study, we analyzed 189 CP donations of 66 donors regarding anti-SARS-CoV-2 anti-S IgG antibody levels. We found a significant correlation between the semi-quantitative SARS-CoV-2 IgG ratio values and in vitro antibody functionality. A time-to-event analysis allowed us to predict the optimal time span of COVID-19 CP donor suitability. We found that high IgG ratio values, which significantly correlate with high in vitro antibody functionality, were suitable for CP donation for a median of 134 days after the first CP donation. Donors with lower IgG ratios were suitable for a median of 53 days. Our data support plasma collection centers to determine optimal points in time for CP donation by means of widely used semi-quantitative laboratory IgG ratio values.

Infective endocarditis - A review of current therapy and future challenges.

Etiological, microbiological and epidemiological factors changed over time, but mortality rates remain high in infective endocarditis (IE). Healthcare-associated IE is nowadays responsible for a significant proportion of cases due to increasing numbers of cardiac devices. Cardiac implantable electronic devices, transcatheter aortic valve replacement, and percutaneous valve repair are meanwhile used, especially in old and sick patients. In suspected IE modified Duke criteria, integrating clinical results, imaging, and biomarkers are traditionally applied. Newer imaging technologies such as multi-slice computed tomography, photon-emission computed tomography, and magnetic resonance imaging might add value to conventional echocardiography in diagnosis and management of IE. Treatment consists of long-term antibiotic therapy, infectiological source control and/or cardiac surgery. Recently, antibiotic parenteral outpatient regimens and partial oral treatment strategies were shown to shorten hospital stays in patients suffering from IE. However, it remains unclear how to best select patients for partial oral therapy. This review describes new trends in diagnosing, imaging, and treating IE in a changing patient collective with particular focus on patients with implantable cardiac devices.

Case Report: Successful Treatment of a Patient with Microfilaremic Dirofilariasis Using Doxycycline.

We report the case of a 56-year-old woman with microfilaremic dirofilariasis due to Dirofilaria repens, which is a very rare condition in humans. Of note, just one of six large-volume blood samples of this patient was positive for microfilariae. Polymerase chain reaction (PCR) and sequencing of the parasite gene determined the geographic origin of the causative helminth. The patient was treated successfully with doxycycline. This drug was chosen because of the patient's reluctance to the use of ivermectin and to provide an anthelmintic effect by targeting the bacterial endosymbiont Wolbachia present in most filarial species.

Cytomegalovirus reactivation and its clinical impact in patients with solid tumors.

Cytomegalovirus reactivation can be life threatening. However, little evidence on its incidence in solid cancers is available. Therefore our single center Cytomegalovirus polymerase chain reaction database with altogether 890 CMV positive blood serum samples of mainly hematological and oncological patients was retrospectively analyzed to examine the occurrence of Cytomegalovirus reactivation in patients with solid tumors, resulting in 107 patients tested positive for Cytomegalovirus reactivation. Seventeen patients with solid cancer and a positive CMV-PCR test were identified, of which eight patients had clinically relevant CMV disease and received prompt antiviral treatment. Five patients fully recovered, but despite prompt antiviral treatment three patients died. Among these three patients two had significant co-infections (in one case EBV and in the other case Aspergillus) indicating that that CMV reactivation was at least one factor contributing to sepsis. The patient with the EBV co-infection was treated in an adjuvant therapy setting for breast cancer and died due to Cytomegalovirus and Epstein-Barr virus associated pneumonia despite intensive therapy. The other two patients had progressive disease of an underlying pancreatic cancer at the time of CMV diagnosis. One patient died due to attendant uncontrollable Aspergillus pneumonia, the other patient most likely died independent from CMV disease because of massively progressive underlying disease. Cytomegalovirus reactivation and disease might be underestimated in routine clinical practice. In our retrospective analysis we show that approximately 50 % of our patients suffering from solid cancers with a positive Cytomegalovirus polymerase chain reaction also had clinically relevant Cytomegalovirus disease requiring antiviral therapy.

Human immunodeficiency virus type 2 infections in Austria.

INTRODUCTION: The first case of human immunodeficiency virus type 2 (HIV-2) seropositivity in Austria was confirmed in 1993 in a dually human immunodeficiency virus type 1 (HIV-1)- and HIV-2-infected patient from Ghana, who died in 2001. Before this investigation, no further HIV-2 infection was published. METHODS: The aim of this study was to describe HIV-2 epidemiology in Austria, using serological and molecular techniques, and to perform a sequence analysis of the circulating viral strains. RESULTS: Six additional cases of HIV-2 were identified from 2000 to 2009. All patients originated from high-prevalence areas. In one patient, the HIV-2 infection was revealed 11 years after initial HIV-1 diagnosis, and further analysis confirmed a dual infection. CONCLUSION: The HIV-2 epidemic has its epicentre in West Africa, but sociocultural issues, especially migration, are contributing to the low but continuous worldwide spread of HIV-2. Diagnosis of HIV-2 implies a different therapeutical management to avoid treatment failure and clinical progression. Differential diagnosis of HIV-1 and HIV-2 is complicated due to antibody cross-reactivity, and paradoxical findings (e.g. declining CD4 cell count despite HIV-1 suppression) may require careful reassessment, especially in patients from endemic countries.

Sequence homologies between Mycoplasma and Chlamydia spp. lead to false-positive results in chlamydial cell cultures tested for mycoplasma contamination with a commercial PCR assay.

Mycoplasma contamination is a frequent problem in chlamydial cell culture. After obtaining contradictory contamination results, we compared three commercial PCR kits for mycoplasma detection. One kit signaled contamination in mycoplasma-free Chlamydia pneumoniae cultures. Sequencing of cloned PCR products revealed primer homology with the chlamydial genome as the basis of this false-positive result.

Design and synthesis of 2-arylbenzimidazoles and evaluation of their inhibitory effect against Chlamydia pneumoniae.

Chlamydia pneumoniae is an intracellular bacterium that responds poorly to antibiotic treatment. Insufficient antibiotic usage leads to chronic infection, which is linked to disease processes of asthma, atherosclerosis, and Alzheimer's disease. The Chlamydia research lacks genetic tools exploited by other antimicrobial research, and thus other approaches to drug discovery must be applied. A set of 2-arylbenzimidazoles was designed based on our earlier findings, and 33 derivatives were synthesized. Derivatives were assayed against C. pneumoniae strain CWL-029 in an acute infection model using TR-FIA method at a concentration of 10 µM, and the effects of the derivatives on the host cell viability were evaluated at the same concentration. Fourteen compounds showed at least 80% inhibition, with only minor changes in host cell viability. Nine most potential compounds were evaluated using immunofluorescence microscopy on two different strains of C. pneumoniae CWL-029 and CV-6. The N-[3-(1H-benzimidazol-2-yl)phenyl]-3-methylbenzamide (42) had minimal inhibitory concentration (MIC) of 10 µM against CWL-029 and 6.3 µM against the clinical strain CV-6. This study shows the high antichlamydial potential of 2-arylbenzimidazoles, which also seem to have good characteristics for lead compounds.

Chlamydia pneumoniae adversely modulates vascular cell properties by direct interaction with signalling cascades.

Due to its dependence on intracellular development Chlamydia pneumoniae has developed numerous strategies to create an adequate environment within its host cells ensuring both chlamydial reproduction and target cell survival. The bacterium that has been related to atherogenesis due to its presence in vascular tissue is able to enter a persistent state of chronic infection in the vasculature that escapes antibiotic targeting. Ingestion of the bacterium results in severe modifications and reprogramming of signalling pathways and the metabolism of the host cell. Processes range from the prevention of direct lysosomal destruction of chlamydial inclusions to the inhibition of host cell apoptosis and an enhanced cellular glucose uptake to maintain energy-consuming mechanisms. Furthermore, infection regularly causes the development of a proinflammatory and proproliferative phenotype in the host cell in vitro, ex vivo and in vivo and own new findings suggest a detrimental proliferative loop within vascular cells upon a modified endothelin-1 axis demonstrating a potential for proatherosclerotic processes in early and progressed atherosclerosis. This review displays crucial mechanisms of Chlamydia pneumoniae-induced interactions with vascular host cell signalling cascades with an emphasis on mitogenic and inflammatory processes as well as target cell activation.

Proliferative stimulation of the vascular Endothelin-1 axis in vitro and ex vivo by infection with Chlamydia pneumoniae.

Endothelin-1 (ET-1) is a vasoactive peptide that modifies vascular function via the G-protein coupled transmembrane receptors, Endothelin-A receptor (ETAR) and Endothelin-B receptor (ETBR). Dysregulation of the ET-1 axis plays a role in atherosclerotic development as it triggers cell proliferation, inflammation, and vasoconstriction. The respiratory pathogen Chlamydia pneumoniae (Cp) has been recovered from atherosclerotic lesions, and related to atherogenesis, via activation of vascular small GTPases and leukocyte recruitment. Cp effectively reprograms host cell signalling and is able to enter an intracellular persistent state in vascular cells that is refractory to antibiotics. Upon chlamydial infection, vascular smooth muscle cells, which do not produce significant ET-1 under physiological conditions were switched into a fundamental source of ET-1 mRNA and protein in a p38-MAP-kinase-dependent pathway. Endothelial cells did not overproduce ET-1 but showed upregulation of mitogenic ETAR mRNA and protein while the counterbalancing ETBR, which regulates ET-1 clearance, remained unaffected. This disruption of the ET-1 axis was confirmed in an ex vivo mouse aortic ring model, and resulted in endothelial cell proliferation that could be abrogated by ETAR-siRNA and the selective ETAR-antagonist BQ-123. Chronic chlamydial infection of the vascular wall might represent a permanent noxious stimulus linked to the endothelial cell proliferation characteristic of early atherosclerosis. Suppression of this deleterious paracrine loop by ETAR antagonism opens up a new option of preventing possible vascular sequelae of otherwise untreatable chronic chlamydial infection. In conclusion, this is the first study to demonstrate infection to dysregulate the ET-1 axis towards inducing a proatherogenic proliferative phenotype.

Chlamydia pneumoniae-induced pathological signaling in the vasculature.

Since its description in 1986, Chlamydia pneumoniae has remained one of the most enigmatic pathogens. This intracellular bacterium is highly seroprevalent, but rarely recovered from cell culture, it can genetically switch between a proliferative and a nonreplicative state and has been linked to a vast number of chronic diseases, most notably to atherosclerosis, as it can be found in the plaques. It has become quite clear that persistent bacteria in atherosclerotic lesions cannot be eradicated by currently available antibiotic treatments and that attempts to do so without a better understanding of the pathobiology of chlamydial persistence are futile. However, there is growing knowledge on how vascular chlamydial infection may lead to the pathological reprogramming of the host cell signaling pathways. Chlamydia pneumoniae is now well known to induce, at least in vitro, the two pathogenetic main events that define atherosclerosis: angiogenesis and inflammation. In vivo a contribution of chlamydial infection to the progression of atherosclerosis remains unproven. This minireview provides a brief overview on the proproliferative and proinflammatory effects of vascular C. pneumoniae infection and their potential link to atherogenesis.