Fetoscopic Laser Ablation for Twin-to-Twin Transfusion Syndrome: A 15-year Review of Perinatal Survival.

Objective Twin to twin transfusion syndrome (TTTS) complicates 5-15% of monochorionic twin pregnancies and untreated is associated with a 90% mortality rate. The aim was to present the perinatal survival of patients with TTTS treated with laser ablation, by a national fetal medicine team. Methods This was a review of all cases of TTTS treated with fetoscopic laser ablation performed from March 2006 through to December 2020. All patients treated with fetoscopic laser were identified from the hospital database. The perinatal outcomes for the overall cohort and the individual Quintero stages were determined. Results A total of 155 cases of TTTS underwent fetoscopic laser ablation during the study period. The median gestational age at diagnosis was 19+1 weeks, with a mean growth discordance of 23.6%. The Quintero stage at diagnosis was: Stage 1 6.5% (10/155), Stage 2 49% (76/155), Stage 3 38.7% (60/155), Stage 4 5.8% (9/155). There was at least one survivor in 83.2% (129/155) of pregnancies, with dual survival in 52.9% (82/155). An increase in the rate of any survivor was observed from 75% (2006-2014) to 94% (2014-2020) (p<0.05). Dual survival decreased with increasing Quintero Stage (p<0.05). 80.6% (125/155) of pregnancies delivered prior to 34+6 weeks gestation. Conclusion Fetoscopic laser ablation is the recommended first line treatment for severe TTTS. We observed a survival rate of at least one twin in 83.2% pregnancies which is comparable to internationally published data on single-centre outcomes.

Interlaboratory Comparison of Six Real-Time PCR Assays for Detection of Bovine Leukemia Virus Proviral DNA.

Quantitative real-time PCR (qPCR) is increasingly being used for the detection of bovine leukemia virus (BLV) proviral DNA. Nevertheless, quality control for the validation and standardization of such tests is currently lacking. Therefore, the present study was initiated by three Office International des Epizooties (OIE) reference laboratories and three collaborating laboratories to measure the interlaboratory variability of six already developed and available BLV qPCR assays. For that purpose, an international panel of 58 DNA samples reflecting the dynamic range of the majority of the assays was distributed to six testing centers. Based on qualitative results, the overall agreement among all six laboratories was moderate. However, significant variability in the measurement of the BLV proviral DNA copy number was observed among different laboratories. Quantitative PCR assays, even when performed by experienced staff, can yield large variability in BLV proviral DNA copy numbers without harmonization. Further standardization of different factors (i.e., utilization of unified protocols and unique calibrators) should increase interlaboratory agreement.

An optimized work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs.

Rapid detection of patients with carbapenemase-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilizing existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n = 10) and anonymized community stool specimens (n = 200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took <5 min, 1 h 30 min and 1 h 50 min, respectively. It was time efficient with a result available in under 4 h, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 h. Utilizing this CPE work-flow would allow a 'same-day' result. Antimicrobial susceptibility testing results, as is current practice, would remain a 'next-day' result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing.

Colonisation with extended-spectrum beta-lactamase (ESBL) not detected in a prevalence study.

BACKGROUND: The Mid-West of Ireland has higher than average national rates of invasive extended-spectrum beta-lactamase (ESBL) bloodstream infections and carbapenemase-producing Enterobacteriaceae (CPE), with increasing numbers of ESBL isolates detected in community-dwelling patients. AIMS: To conduct a point prevalence study in a convenience sample of the Mid-West population with the aim of determining the extent of ESBL colonisation. METHODS: Utilising anonymised community stool samples that had completed routine analysis, we conducted a point prevalence study over a 4-week period on all samples that met defined inclusion and exclusion criteria. Limited epidemiological data was recorded: (1) age of patient, (2) gender, and (3) sender location. From these stool specimens, rectal swabs were inoculated (eSwab™ 480CE, Copan, Italy), which were subsequently cultured on selective chromogenic agar (Colorex™ ESBL). Culture plates were incubated aerobically at 37 °C for 24 h. RESULTS: Of 195 samples processed, 58 % (n = 112) were from females. The median patient age was 62.4 years (range 20-94 years). 186 samples (95 %) originated from general practitioner clinics. During the study period, only nine eligible stool samples were received from LTCF (6 public). From 195 Colorex™ ESBL chromogenic agar plates cultured, no ESBL-producing organisms were detected. CONCLUSIONS: This community point prevalence study did not identify ESBL colonisation despite high numbers of patients with invasive ESBL bloodstream infections presenting for admission in our institution. We believe this may be because of our small sample size. Data regarding antimicrobial exposure and other risk factors for ESBL colonisation were also not available. We remain vigilant for ESBL-producing organisms.

An Irish outbreak of New Delhi metallo-ß-lactamase (NDM)-1 carbapenemase-producing Enterobacteriaceae: increasing but unrecognized prevalence.

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) may cause healthcare-associated infections with high mortality rates. New Delhi metallo-ß-lactamase-1 (NDM-1) is among the most recently discovered carbapenemases. AIM: To report the first outbreak of NDM-1 CPE in Ireland, including microbiological and epidemiological characteristics, and assessing the impact of infection prevention and control measures. METHODS: This was a retrospective microbiological and epidemiological review. Cases were defined as patients with a CPE-positive culture. Contacts were designated as roommates or ward mates. FINDINGS: This outbreak involved 10 patients with a median age of 71 years (range: 45-90), located in three separate but affiliated healthcare facilities. One patient was infected (the index case); the nine others were colonized. Nine NDM-1-producing Klebsiella pneumoniae, an NDM-1-producing Escherichia coli and a K. pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae were detected between week 24, 2014 and week 37, 2014. Pulsed-field gel electrophoresis demonstrated similarity. NDM-1-positive isolates were meropenem resistant with minimum inhibitory concentrations (MICs) ranging from 12 to 32 µg/mL. All were tigecycline susceptible (MICs ≤1 µg/mL). One isolate was colistin resistant (MIC 4.0 µg/mL; mcr-1 gene not detected). In 2015, four further NDM-1 isolates were detected. CONCLUSION: The successful management of this outbreak was achieved via the prompt implementation of enhanced infection prevention and control practices to prevent transmission. These patients did not have a history of travel outside of Ireland, but several had frequent hospitalizations in Ireland, raising concerns regarding the possibility of increasing but unrecognized prevalence of NDM-1 and potential decline in value of travel history as a marker of colonization risk.

Incidence, management and outcomes of the first cfr-mediated linezolid-resistant Staphylococcus epidermidis outbreak in a tertiary referral centre in the Republic of Ireland.

AIM: To report the first Irish outbreak of cfr-mediated linezolid-resistant Staphylococcus epidermidis. METHODS: Linezolid-resistant S. epidermidis isolated at University Hospital Limerick from four blood cultures, one wound and four screening swabs (from nine patients) between April and June 2013 were characterized by pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing. Antibiotic susceptibilities were determined according to the guidelines of the British Society for Antimicrobial Chemotherapy. The outbreak was controlled through prohibiting prescription and use of linezolid, adherence to infection prevention and control practices, enhanced environmental cleaning, isolation of affected patients, and hospital-wide education programmes. FINDINGS: PFGE showed that all nine isolates represented a single clonal strain. MLST showed that they belonged to ST2, and SCCmec typing showed that they encoded a variant of SCCmecIII. All nine isolates were cfr positive, and eight isolates were positive for the G2576T 23S rRNA mutation commonly associated with linezolid resistance. Isolates exhibited multiple antibiotic resistances (i.e. linezolid, gentamicin, methicillin, clindamycin, ciprofloxacin, fusidic acid and rifampicin). The adopted infection prevention intervention was effective, and the outbreak was limited to the affected intensive care unit. CONCLUSIONS: This is the first documented outbreak of cfr-mediated linezolid-resistant S. epidermidis in the Republic of Ireland. Despite this, and due to existing outbreak management protocols, the responsible micro-organism and source were identified efficiently. However, it became apparent that staff knowledge of antimicrobial susceptibilities and appropriate hygiene practices were suboptimal at the time of the outbreak, and that educational interventions (and re-inforcement) are necessary to avoid occurrence of antimicrobial resistance and outbreaks such as reported here.

Detection of Bovine Leukaemia Virus Antibodies and Proviral DNA in Colostrum Replacers.

Great Britain has been bovine leukaemia virus (BLV) disease free since 1999. We recently reported three separate incidents of BLV seropositivity on farms with home-reared cattle due to the use of colostrum replacer rather than infection with BLV (Emerg. Infect. Dis., 19, 2013, 1027). These cases were all linked via the use of the same brand of colostrum replacer. Here, we investigate further by examining multiple brands of colostrum replacer for proviral DNA and BLV antibodies. BLV antibodies were detected in 7 of the colostrum replacers tested, with PCR concurring in two cases. Thus, the use of these BLV antibody-positive colostrum replacers may also lead to false-positive serological diagnostics.

The first case of a bull persistently infected with Border disease virus in New Zealand.

CASE HISTORY: Poor reproductive performance was observed in 62 dairy heifers, with a pregnancy rate of 23% following 57 days mating with one 3-year-old and two 2-year old Belted Galloway bulls that were sourced from separate sheep and beef farms. CLINICAL FINDINGS: The 3-year-old bull was small for its age with small testes. This bull was seropositive for bovine viral diarrhoea virus type I (BVDV 1) using an Ag-ELISA, and positive on PCR for border disease virus (BDV). DIAGNOSTIC INVESTIGATION: Phylogenetic analysis of the BDV isolate from the affected bull indicated that it was part of the BDV 1 group. For 40 of the heifers exposed to the bull that were tested, all of them had a positive VNT (virus neutralisation test) titre to both BDV (titre≥1:4) and BVDV 1 (titre>1:4). On the farm of origin of the affected bull there was no evidence of BDV circulating between cattle. DIAGNOSIS: Persistent infection of a bull with BDV. CLINICAL RELEVANCE: Cattle persistently infected with BDV can act as a source of virus for infection of other cattle. The benefit of testing cattle for bovine viral diarrhoea could be enhanced by using tests that also detect BDV.

Radiographic identification of the equine ventral conchal bulla.

Involvement of the ventral conchal sinus (VCS) is an important diagnostic and prognostic feature in cases of the equine sinus disease. The authors aimed to ascertain if the caudo-dorsal extension of the VCS, the ventral conchal bulla (VCB) is identifiable on plain radiographs of cadaver skulls without sinus disease. Bilateral frontonasal sinus flaps were made in 10 equine cadaver skulls. Plain lateral, lateral oblique and dorso-ventral radiographs were then obtained followed by the same views taken with stainless steel wire outlining the caudal border of the VCB. Plain radiographs were randomised and blindly evaluated by two observers who marked where they believed the VCB to be positioned. This was then correlated with the true position of the VCB using radiographs with wires in place. The ease of identification of the VCB was classified as 'easy' or 'difficult'. The VCB was correctly identified in 70 per cent of lateral radiographs, but only 45 per cent of lateral oblique radiographs and 17 per cent of dorso-ventral radiographs. If a clinician was confident that he or she could identify the VCB, they were usually correct. Conversely if the clinician judged VCB identification as 'difficult', they usually identified it incorrectly. In the authors' clinical experience, the VCB of horses with sinusitis involving this compartment is more radiologically evident than in clinically normal horses. Knowledge of the normal radiographic anatomy of this structure should aid clinicians in identifying horses with sinusitis affecting the VCS.

Use of tongue ties in thoroughbred racehorses in the United Kingdom, and its association with surgery for dorsal displacement of the soft palate.

The prevalence of the use of tongue ties, calculated from 60 randomly selected race meetings held in the UK during 2001 to 2003, was 5.0 per cent. After its first use on an individual horse a tongue tie was used in an average of 77 per cent of its races during the first 12 months, but after this time period, in only 55 per cent of its races. Thirty-nine per cent of horses that underwent surgery for dorsal displacement of the soft palate raced with a tongue tie preoperatively, and 41 per cent of these surgical cases raced with a tongue tie postoperatively.

Continuous-flow laboratory simulation of stream water quality changes downstream of an untreated wastewater discharge.

In regions of the world with poor provision of wastewater treatment, raw sewage is often discharged directly into surface waters. This paper describes an experimental evaluation of the fate of two organic chemicals under these conditions using an artificial channel cascade fed with a mix of settled sewage and river water at its upstream end and operated under continuous steady-state conditions. The experiments underpin an environmental risk assessment methodology based on the idea of an "impact zone" (IZ) - the zone downstream of wastewater emission in which water quality is severely impaired by high concentrations of unionised ammonia, nitrite and biochemical oxygen demand (BOD). Radiolabelled dodecane-6-benzene sulphonate (DOBS) and aniline hydrochloride were used as the model chemical and reference compound respectively. Rapid changes in (14)C counts were observed with flow-time for both these materials. These changes were most likely to be due to complete mineralisation. A dissipation half-life of approximately 7.1 h was observed for the (14)C label with DOBS. The end of the IZ was defined as the point at which the concentration of both unionised ammonia and nitrite fell below their respective predicted no-effect concentrations for salmonids. At these points in the cascade, approximately 83 and 90% of the initial concentration of (14)C had been removed from the water column, respectively. A simple model of mineral nitrogen transformations based on Michaelis-Menten kinetics was fitted to observed concentrations of NH(4), NO(2) and NO(3). The cascade is intended to provide a confirmatory methodology for assessing the ecological risks of chemicals under direct discharge conditions.

Effect of 'tongue tie' use on racing performance of thoroughbreds in the United Kingdom.

REASONS FOR PERFORMING STUDY: There is contradictory published evidence on the potential efficacy of 'tongue ties' (TTs) for treatment of intermittent dorsal displacement of the soft palate (DDSP) in racehorses. OBJECTIVES: To evaluate the effect of TTs on racing performance in Thoroughbred racehorses in the U.K. using a retrospective cohort study. METHODS: Data on individual horses' lifetime racing performance and TT use were retrieved from the Racing Post Online Database. Exposed cases were horses that ran with a TT in randomly chosen race meetings on one of 60 randomly chosen dates from 2001-2003. Unexposed (control) horses were matched to each exposed horse. Various measures of racing performance were analysed both within and between exposed and unexposed groups. Subsets of exposed horses that ran for 3 or 5 consecutive starts wearing TTs and their matched controls were analysed separately to examine the effect of repeated TT use. RESULTS: The inclusion criteria were fulfilled by 108 horses. The odds ratio for 'improvement' in race earnings between exposed and unexposed horses was 1.85 for horses that ran at least once with a TT, and 3.60 and 4.24, respectively, for horses that ran in 3 or 5 consecutive races wearing a TT. After instigation of TT use, horses that ran in 3 or 5 consecutive races wearing a TT had a significant increase in earnings when they ran wearing a TT compared to their pre-TT races. CONCLUSIONS AND POTENTIAL RELEVANCE: The use of a TT appears to have a beneficial effect on racing performance in a selected population of Thoroughbred racehorses.

The behaviour of linear alkyl benzene sulphonate under direct discharge conditions in Vientiane, Lao PDR.

Direct discharge of untreated sewage to surface waters is a common practice in many parts of the world. However, relatively little is known about the behaviour of synthetic organic pollutants under these conditions. This paper describes a sampling campaign designed to track changes in water quality in a surface water system in Vientiane (Lao PDR) receiving significant quantities of untreated waste water. The study was based on following in-channel transport using a fluorescent tracer injected as a pulse, with a focus on the anionic surfactant linear alkylbenzene sulphonate (LAS) and ammonia. Water samples were collected at a number of stations with sampling times estimated to coincide with solute time-of-travel. The reduction in LAS concentration with flow-time could be approximated by first-order kinetics with a half life of about 7 h. Free ammonia concentrations decreased more slowly than LAS and remained above the level believed to be toxic for sensitive aquatic species along the entire channel. Changes in the ratios of LAS alkyl chain homologues to total LAS concentrations suggest a preferential removal of longer chain lengths. The role of biodegradation in the removal of LAS was confirmed by the presence of LAS metabolites (sulphophenylcarboxylates, SPCs) which increased systematically (as a fraction of LAS remaining) with flow-time.

Dissecting HIV fusion: identifying novel targets for entry inhibitors.

Significant momentum has been recently generated in understanding the HIV fusion process. This has led to the development of a host of HIV entry inhibitors which are currently in preclinical and/or clinical development or have been approved for clinical use. In this review we update our understanding of HIV fusion, specifically highlighting novel mechanisms and agents that inhibit this process. Major focus will be placed on three key areas. Initially viral attachment will be reviewed as recent developments in this field emphasize the importance of understanding cell type specific interactions with HIV. This has aided in identifying promising targets for the development of attachment inhibitors. Secondly, we will review the role of cellular lipids in HIV entry. Glycosphingolipids have been shown to interact with different components of the HIV fusion machinery and agents that perturb glycosphingolipid biosynthesis have inhibitory effects on HIV fusion. Likewise, manipulating ceramide biosynthesis also inhibits HIV fusion. Here, we describe how manipulating cellular lipids inhibits HIV fusion and how lipid biosynthesis can be modulated to potentially prevent HIV infection. We end this review by discussing the notion of targeting select host cell proteins for HIV therapy. We will review the role of the cellular proteins PDI, defensins and cytoskeletal proteins in facilitating the fusion reaction. As our understanding of the HIV fusion process increases, the identification of targets for developing entry inhibitors becomes more diverse. Given the rapid resistance of HIV to any selective pressure this is an important avenue in the advancement of drug therapy.

The clinical potential of sphingolipid-based therapeutics.

The era of sphingolipid-based therapeutics is upon us. A large body of work has been accumulating that demonstrates the distinct biological roles of sphingolipids in maintaining a homeostatic environment and in responding to environmental stimuli to regulate cellular processes. It is thus necessary to further investigate alterations in sphingolipid-metabolism in pathological conditions and, in turn, try to exploit altered sphingolipid-metabolizing enzymes and their metabolites as therapeutic targets. This review will examine how advances in the fields of drug delivery, drug discovery, synthetic chemistry, enzyme replacement therapy, immunobiology, infectious disease and nanotechnology have delivered the potential and promise of utilizing and/or targeting sphingolipid metabolites as therapies for diverse diseases.

The effect of species models on estimates of within-lineage variation in integration.

Species may be modeled as comprised of individuals, populations or a virtual code. A virtual code can be understood as general potential that appears as actualization within specific environmental, both internal and external, contexts. These general potentials form a capacity to network that allows potentials to be expressed and offers robustness through its interconnections. In the present work, the degree of within-lineage variation in integration was not strongly model-dependent. However, the relationships among model-dependent estimates of such variation and within-lineage phyletic variation were not equal. The strongest relationship was between within-lineage variation in integration, when species were modeled as a virtual code, and within-lineage phyletic variation. The second strongest, and only other statistically significant relationship, was between variation in integration when species were modeled as a virtual code and as a collection of populations. The last result argues for a strong ontogenetic and micro-environmental effect on the expression of features in an individual. If species were a virtual code they would evolve by incorporation of all attributes, ontogenetic, environmental and genetic into that code until it becomes unstable and bifurcates. Species as a virtual code, an approach that explicitly incorporates developmental change into evolution, is a non-material representation of species as a complex information system, incorporating, if we refer to mathematical analysis, both the real and the imaginary. If one wished to stress the material, this study could be seen as empirical documentation of species as information systems.

Detection and strain differentiation of European bat lyssaviruses using in situ hybridisation.

A protocol suitable for the detection of rabies virus and the related European bat lyssaviruses type 1 and 2 is described. In situ hybridisation, employing digoxigenin labelled riboprobes was used for the detection of lyssavirus RNA in mouse-infected brain tissue. The principal advantage of this technique, compared to routine methods used for histopathology, is that this method is robust, highly sensitive, and specific for assessing the presence of RNA in different tissues. An additional advantage is that there is no longer any requirement for high laboratory bio-containment, once the tissue under investigation has been safely fixed. Using this method, both genomic and messenger RNA were detected. The ability to detect messenger RNA is indicative of the presence of replicating virus and therefore, this technique is a powerful diagnostic tool for the routine detection of strains of rabies virus including the European bat lyssaviruses.