Distribution of individual members of the mosquito Anopheles maculipennis complex in Germany identified by newly developed real-time PCR assays

Owing to their role as vectors of malaria parasites, species of the Anopheles maculipennis complex (Diptera: Culicidae) Meigen were intensively studied in the past, but with the disappearance of malaria in Germany in the middle of the last century, the interest in this field of research declined. A comprehensive ecological analysis of the current species distribution for Germany is lacking. Between 2010 and 2013, a total of 1445 mosquitoes of the An. maculipennis complex were collected at 72 different sites in Germany. The samples comprise 722 single individuals as well as 723 individuals in 90 pools of up to 25 mosquitoes. All samples were analysed with newly developed species-specific qPCR assays for the identification of the four German species using nucleotide differences within the internal transcribed spacer 2 (ITS2) ribosomal DNA. All gathered data were used for species distribution modelling. The overall prevalence of An. messeae s.l. was highest with 98.89% of all pools; An. daciae with 6.93% of all individuals and An. messeae s.s. with 69.53%. The prevalence of the other two species was relatively low: An. maculipennis s.s. with 13.30% of all individuals (6.67% of all pools) and An. atroparvus with 1.80% of all individuals (1.11% of all pools).

Isolation of atypical enteropathogenic Escherichia coli from chicken and chicken-derived products

Atypical enteropathogenic Escherichia coli (EPEC) strains from chicken and chicken-derived products were isolated and characterised. The strains presented a wide variety of serotypes, some have been reported in other animal species (O2:H40, O5:H40) and in children with diarrhoea (O8:H-). Most of the strains carried intimin β. The results indicate that chicken and chicken products are important sources of atypical EPEC strains that could be associated with human disease, and highlight the need to improve hygiene practices in chicken slaughtering and meat handling.

Genetic characterization of Shiga toxin-producing Escherichia coli O26:H11 strains isolated from animal, food, and clinical samples

The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx_1a or stx_2a subtypes. Interestingly, stx_2a-positive O26:H11 rarely isolated from cattle in other countries showed to be an important proportion of O26:H11 strains circulating in cattle and food in our region. Seventeen percent of the isolates harbored more than one gene associated with antimicrobial resistance. In addition to stx, all strains contained the virulence genes eae-β, tir, efa, iha, espB, cif, espA, espF, espJ, nleA, nleB, nleC, and iss; and all except one contained ehxA, espP, and cba genes. On the other hand, toxB and espI genes were exclusively observed in stx₂-positive isolates, whereas katP was only found in stx_1a-positive isolates. Our results show that O26:H11 STEC strains circulating in Argentina, including those isolated from humans, cattle, and meat products, present a high pathogenic potential, and evidence that cattle can be a reservoir of O26:H11 strains harboring stx_2a.

Radiographic contrast media alterate the localization of actin/band4.9 in the membrane cytoskeleton of human erythrocytes

Different radiographic contrast media (RCM) were shown to induce morphological changes of blood cells (e.g. erythrocytes or thrombocytes) and endothelial cells. The echinocytic shape change of erythrocytes, particularly, affords alterations of the membrane cytoskeleton. The cytoskeleton plays a crucial role for the shape and deformability of the red blood cell. Disruption of the interaction between components of the red blood cell membrane cytoskeleton may cause a loss of structural and functional integrity of the membrane. In this study band4.9 and actin as components of the cytoskeletal junctional complex were examined in human erythrocytes after suspension in autologous plasma or in plasma RCM mixtures (30% v/v Iodixanol-320 or Iopromide-370) followed by a successive double staining with TRITC-/FITC-coupled monoclonal antibodies. After adding Iopromide-370 to the plasma in practically none of the cells the rounded conformation of the membrane cytoskeleton - as it appeared in cells suspended in autologous plasma - was found. In addition, Iopromide-370 induced thin lines and coarse knob-like structures of band4.9 at the cell periphery while most cell centers were devoid of band4.9, and a box-like arrangement of bands of band4.9. A dissociation between colours red (actin) and green (band4.9) occurred as well. In contrast, erythrocytes suspended in a plasma/Iodixanol-320 mixture showed a membrane cytoskeleton comparable to cells suspended in autologous plasma, Similar results were found with respect to the distribution of actin. This study revealed for the first time RCM-dependent differences in band4.9 activities as possible pathophysiological mechanism for the chemotoxicity of radiographic contrast media.

Association between exploratory activity and social individuality in genetically identical mice living in the same enriched environment

We previously reported that inbred, genetically identical mice living in one enriched environment develop individual behavioral trajectories, indicating increasingly different levels of spatial exploratory behavior as quantified by roaming entropy. Cumulative roaming entropy (cRE) correlated positively with adult hippocampal neurogenesis, a type of plasticity involved in the flexible integration of new information into existing contexts (Freund et al., 2013). The study on which we report here was done in parallel to that first experiment, but here we acquired detailed observational data on the behavior of individual mice. Roaming entropy (RE) was again assessed in real-time with an antenna-based system over the entire experimental period of 3months. Compared to the least active mice in the enclosure (low number of antenna contacts), the most active animals showed tendencies of increased socially interactive behavior in the final observation block whereas least active mice displayed more self-related behavior (non-social local exploration and play). When looking at roaming behavior, we discovered that RE correlated negatively with latent factors representing social exploratory and non-social exploratory and play behavior. Adult neurogenesis could not be studied in the present cohort but we do know that under identical conditions, cumulative RE correlated positively with adult hippocampal neurogenesis. We can thus hypothesize that the mice with more exploratory experience in terms of areal coverage (as quantified by RE) and related greater levels of adult hippocampal plasticity, might also be the ones that were less involved in interactions within the group and, hence, more individualistic. While this remains to be confirmed experimentally, the present data suggest that the described mechanism of individualization, which has previously been shown to be hippocampus-dependent, has a social component.

[Mosquitoes as vectors for exotic pathogens in Germany]

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics.

Interaction of human umbilical vein endothelial cells (HUVEC) with platelets in vitro: Influence of platelet concentration and reactivity

Endothelialisation of polymer-based cardiovascular implants is one strategy to render biomaterials hemocompatible. The evaluation of the functionality and the confluence of an endothelial cell (EC) monolayer in vitro is therefore of crucial importance, because a non-functional or non-confluent EC monolayer can contribute to the failure of vascular grafts. Moreover, the comparison of different potential biomaterials regarding their ability to induce the formation of a functional confluent EC monolayer is of great value. Most of the currently reported in vitro studies focus on direct or indirect markers of EC behaviour. However, these studies still lack the final proof that the EC monolayer, which can be developed on polymers is confluent and functional. In this study, we investigated the suitability of an in vitro co-culture of human umbilical vein endothelial cells (HUVEC) with platelets to predict the functionality of an EC monolayer. The interaction of platelets with HUVEC was evaluated depending on the concentration of the platelets in the added plasma and of the reactivity of the platelets to pharmacological stimuli. For this purpose, HUVEC were seeded in a 24 well plate. After three days of cultivation, platelets were added to the HUVEC cell culture medium to final concentrations of 200, 2,000 or 20,000 platelets/μl (n = 7 each). The platelets were processed immediately after blood collection and added to the HUVEC culture after a 30 minutes resting period. As a first control, an EC monolayer just cultured with EC medium was used. As a second control EC supplemented with plasma without platelets were applied. The HUVEC monolayer was investigated microscopically after 1 hour of platelet exposition. The addition of thrombocytes to EC affected the EC adherence dependent on the initial cell seeding number of HUVEC, the platelet concentration and also on the reactivity of platelets added. In both controls no significant EC detachment was detected. The results demonstrated a significant influence of platelet concentration and reactivity on the adherence of EC in a static model.

Land-use impacts on fatty acid profiles of suspended particulate organic matter along a larger tropical river

Land-use change, such as agricultural expansion and urbanization, can affect riverine biological diversity and ecosystem functioning. Identifying the major stressors associated with catchment land-use change is a prerequisite for devising successful river conservation and restoration strategies. Here, we analyzed land-use effects on the fatty acid (FA) composition and concentrations in suspended particulate organic matter (SPOM) along a fourth-order tropical river, the Rio das Mortes. Thereby, we aimed at testing the potential of fatty acids in riverine suspended particulate organic matter (SPOM-FAs) as indicators of land-use change in tropical catchments, and at identifying major human impacts on the biochemical composition of SPOM, which represents an important basal energy and organic matter resource for aquatic consumers. River water SPOM and total FA concentrations ranged between 2.8 and 10.2mg dry weight(DW)L(-1) and between 130.6 and 268.2μg DW L(-1), respectively, in our study. Urbanization was the only land-use category correlating with both FA composition and concentrations, despite its low contribution to whole catchment (1.5-5.6%) and riparian buffer land cover (1.7-6.6%). Higher concentrations of saturated FAs, especially C16:0 and C18:0, which are the main components of domestic sewage, were observed at sampling stations downstream of urban centers, and were highly correlated to urbanization, especially within the 60m riparian buffer zone. Compared to water chemical characteristics (inorganic nutrients, dissolved oxygen, pH, and specific conductance) and river habitat structural integrity, FA variables exhibited a higher variability along the investigated river and were more strongly correlated to urban land use, suggesting that SPOM-FA profiles may be an efficient indicator of urban land-use impacts on larger tropical rivers. High total FA concentrations in the SPOM of urbanized tropical rivers may represent high-energy biochemical subsidies to food webs, potentially leading to changes in functional ecosystem characteristics, such as bacterial and suspension-feeder production.

Viability and function of primary human endothelial cells on smooth poly(ether imide) films

Poly(ether imide) (PEI) is being explored as potential biomaterial for cardiovascular applications. Different studies showed that human umbilical venous endothelial cells (HUVEC) are able to adhere and proliferate on PEI membranes (R(q) = 13.20 ± 1.58 nm). A recently published study revealed evidence for much lower platelet adhesion on very smooth PEI-films (R(q) = 2.37 ± 1.40 nm). Therefore, we explored whether primary human venous endothelial cells (HUVEC) are able to adhere and proliferate on such very smooth PEI-films compared to tissue-cultured polystyrene (TCP) as reference material. Cytotoxicity testing revealed that PEI had a slight cytotoxic effect on HUVEC accompanied by a marginal reduced integrity of the plasma membrane and a significant lower mitochondrial activity. However long-term seeding experiments up to eleven days exhibited that HUVEC were able to proliferate on the PEI-films till confluence (TCP 96,190 ± 18,289 cells/cm(2); PEI 91,590 ± 19,583 cells/cm(2)). Further studies are planned to monitor the influence of shear force on the endothelial cell monolayer in a dynamic test system to determine its stability in view of shear resistant endothelialization of PEI for cardiovascular devices.

[Atlas fracture due to aneurysmal bone cyst after minor trauma]

Aneurysmal bone cysts predominantly occur in young adults and the long bones, the lumbar spine and the pelvis are mainly affected. This article presents the case of a 22-year-old woman with the very rare localization of an aneurysmal bone cyst of the atlas and an atlas fracture after a minor trauma. The initial radiological diagnosis was a suspicted aneurysmal bone cyst which was confirmed histologically. Due to the unstable fracture it was decided to carry out surgical treatment with occipitocervical stabilization in combination with a transoral bone graft. After a period of 11 months the fracture had completely healed and the implants were removed without any complications.

Descriptions of members of theSimulium damnosumcomplex (Diptera: Simuliidae) from southern Africa, Ethiopia and Tanzania

This paper presents cytotaxonomic details of five populations of the Simulium damnosum complex from South Africa, Swaziland and Ethiopia. The 'Nkusi SW' and 'Pienaars' forms are newly designated members of the complex from South Africa, but the taxonomic rank of an isolate indistinguishable chromosomally from the 'Nkusi' cytoform remains unclear. From Ethiopia two cytoforms were identified, one of which shares two diagnostic chromosome inversions with the cytoform 'Kisiwani' from Tanzania. The second form belongs to S. kaffaense, and is the suspected local vector of Onchocerca volvulus. In addition, a re-analysis of the cytoform 'Kibwezi' from north-eastern Tanzania provided further insights into its population subdivision, and its genetic and morphological characteristics. Cytotaxonomic similarities between 'Kibwezi', S. mengense and S. pandanophilum, along with their biogeography, indicate a relict status of each of these taxa.

Incrimination ofSimulium thyolense(Diptera: Simuliidae) as the anthropophilic blackfly in the Thyolo focus of human onchocerciasis in Malawi

The sibling species of the Simulium damnosum complex that are potential vectors in the foci of human onchocerciasis found in southern Malawi (the southern-most foci in Africa) were identified, using a combination of cytotaxonomic and molecular techniques. Simulium thyolense was found to be the most abundant species within the foci (representing 91% of the larvae collected), whilst S. kilibanum and cytoforms of the 'Ketaketa' subcomplex were the dominant members of the complex found outside of the foci. As all 188 biting female flies collected from the Thyolo, Mwanza and Mulanje foci were identified as S. thyolense, this species is probably the only significant vector of Onchocerca volvulus in the area, and the other Simulium species collected are assumed to be zoophilic. The results confirm the diagnostic value of the size of the amplicon(s) produced in PCR based on the sequences coding for the internal-transcribed-spacer region of the nuclear ribosomal DNA (ITS-1 rDNA), with a characteristic 340bp amplicon for S. thyolense. Chromosomal polymorphisms within S. thyolense indicate some degree of geographical isolation of the 'Thyolo-Mulanje' focus from the Mwanza focus.

The cytotaxonomy and morphotaxonomy ofSimulium mengense(Diptera: Simuliidae)

Human onchocerciasis is hyper-endemic in south-western Cameroon and the island of Bioko. The vector on the island is the endemic 'Bioko' form of Simulium yahense. On the mainland, S. damnosum s.s., S. squamosum and S. mengense are recorded around Mount Cameroon but their contribution to transmission in the area is unclear. As elimination of onchocerciasis, through vector eradication, is a possibility on the island, it is important to be able to identify vector flies which might migrate to Bioko from the mainland. The morphologies of S. damnosum s.s. and S. squamosum are already well known. New cytotaxonomic and morphotaxonomic descriptions of S. mengense, a species which is less well known, are presented. Simulium mengense can be distinguished from the other cytospecies in the area by the presence of tufts of hair-like setae on the larval thorax, the presence of hairs on the subcostal vein of the adult female, and by the scutal pattern of the adult male. Although Vajime and Dunbar described seven fixed inversions in S. mengense, in 1977, nine were observed in the present study. Of the nine, three were the same as Vajime and Dunbar's but the other six were either missed or misinterpreted by them.

High failure rate of trochanteric fracture osteosynthesis with proximal femoral locking compression plate

INTRODUCTION

Stable reconstruction of proximal femoral (PF) fractures is especially challenging due to the peculiarity of the injury patterns and the high load-bearing requirement. Since its introduction in 2007, the PF-locking compression plate (LCP) 4.5/5.0 has improved osteosynthesis for intertrochanteric and subtrochanteric fractures of the femur. This study reports our early results with this implant.

METHODS

Between January 2008 and June 2010, 19 of 52 patients (12 males, 7 females; mean age 59 years, range 19-96 years) presenting with fractures of the trochanteric region were treated at the authors' level 1 trauma centre with open reduction and internal fixation using PF-LCP. Postoperatively, partial weight bearing was allowed for all 19 patients. Follow-up included a thorough clinical and radiological evaluation at 1.5, 3, 6, 12, 24, 36 and 48 months. Failure analysis was based on conventional radiological and clinical assessment regarding the type of fracture, postoperative repositioning, secondary fracture dislocation in relation to the fracture constellation and postoperative clinical function (Merle d'Aubigné score).

RESULTS

In 18 patients surgery achieved adequate reduction and stable fixation without intra-operative complications. In one patient an ad latus displacement was observed on postoperative X-rays. At the third month follow-up four patients presented with secondary varus collapse and at the sixth month follow-up two patients had 'cut-outs' of the proximal fragment, with one patient having implant failure due to a broken proximal screw. Revision surgeries were performed in eight patients, one patient receiving a change of one screw, three patients undergoing reosteosynthesis with implantation of a condylar plate and one patient undergoing hardware removal with secondary implantation of a total hip prosthesis. Eight patients suffered from persistent trochanteric pain and three patients underwent hardware removal.

CONCLUSIONS

Early results for PF-LCP osteosynthesis show major complications in 7 of 19 patients requiring reosteosynthesis or prosthesis implantation due to secondary loss of reduction or hardware removal. Further studies are required to evaluate the limitations of this device.