18 research outputs found
Vancomycin and/or multidrug-resistant Citrobacter Freundii altered the metabolic pattern of soil microbial community
Despite many studies, our knowledge on the impact of antibiotics and antibiotic-resistant bacteria on the metabolic activity of soil microbial communities is still limited. To ascertain this impact, the community level physiological profiles (CLPPs) and the activity of selected enzymes (dehydrogenase, urease, and phosphatases) in soils treated with vancomycin (VA) and/or multidrug resistant Citrobacter freundii were determined during a 90-day experiment. A multivariate analysis and the resistance (RS)/resilience (RL) concept were used to assess the potential of native microorganisms to maintain their catabolic activity under exposure of VA and/or a high level of C. freundii. In addition, the dissipation rate of VA was evaluated in non-sterile (nsS) and sterile (sS) soils. The results revealed a negative impact of VA on the metabolic activity of soil microorganisms on days 1, 15, and 30 as was showed by a decrease in the values of the CLPP indices (10-69%) and the enzyme activities (6-32%) for treated soils as compared to the control. These observations suggested a low initial resistance of soil microorganisms to VA and/or C. freundii but they were resilient in the long term. Considering the mean values of the RS index, the resistance of measured parameters was categorized in the following order: alkaline phosphatase (0.919) > acid phosphatase (0.899) > dehydrogenase (0.853) > the evenness index (0.840) > urease (0.833) > the Shannon-Wiener index (0.735) > substrate richness (0.485) > the AWCD (0.301). The dissipation process of VA was relatively fast and independent of the concentration used. The DT50 values for VA applied at both concentrations were about 16 days. In addition, the dissipation of VA in nsS was three times faster compared to the dissipation of antibiotic in sS. In conclusion, both CLPP and enzyme activities assays appeared to be useful tool for the determination of disturbances within soil microbial communities and used together may be helpful to understand the changes in their catabolic features. The entry of large quantities of VA and/or C. freundii into soil may temporarily change microbial activity thus pose a potential risk for soil functioning
Identification of novel risk loci and causal insights for sporadic Creutzfeldt-Jakob disease: a genome-wide association study
Background: Human prion diseases are rare and usually rapidly fatal neurodegenerative disorders, the most common being sporadic Creutzfeldt-Jakob disease (sCJD). Variants in the PRNP gene that encodes prion protein are strong risk factors for sCJD but, although the condition has similar heritability to other neurodegenerative disorders, no other genetic risk loci have been confirmed. We aimed to discover new genetic risk factors for sCJD, and their causal mechanisms.
Methods: We did a genome-wide association study of sCJD in European ancestry populations (patients diagnosed with probable or definite sCJD identified at national CJD referral centres) with a two-stage study design using genotyping arrays and exome sequencing. Conditional, transcriptional, and histological analyses of implicated genes and proteins in brain tissues, and tests of the effects of risk variants on clinical phenotypes, were done using deep longitudinal clinical cohort data. Control data from healthy individuals were obtained from publicly available datasets matched for country.
Findings: Samples from 5208 cases were obtained between 1990 and 2014. We found 41 genome-wide significant single nucleotide polymorphisms (SNPs) and independently replicated findings at three loci associated with sCJD risk; within PRNP (rs1799990; additive model odds ratio [OR] 1·23 [95% CI 1·17-1·30], p=2·68 × 10-15; heterozygous model p=1·01 × 10-135), STX6 (rs3747957; OR 1·16 [1·10-1·22], p=9·74 × 10-9), and GAL3ST1 (rs2267161; OR 1·18 [1·12-1·25], p=8·60 × 10-10). Follow-up analyses showed that associations at PRNP and GAL3ST1 are likely to be caused by common variants that alter the protein sequence, whereas risk variants in STX6 are associated with increased expression of the major transcripts in disease-relevant brain regions.
Interpretation: We present, to our knowledge, the first evidence of statistically robust genetic associations in sporadic human prion disease that implicate intracellular trafficking and sphingolipid metabolism as molecular causal mechanisms. Risk SNPs in STX6 are shared with progressive supranuclear palsy, a neurodegenerative disease associated with misfolding of protein tau, indicating that sCJD might share the same causal mechanisms as prion-like disorders.
Funding: Medical Research Council and the UK National Institute of Health Research in part through the Biomedical Research Centre at University College London Hospitals National Health Service Foundation Trust
Neuro-COVID-19: an insidious virus in action
Introduction: The punishing effect of the pandemic outbreak of the disease termed COVID-19 (coronavirus disease-19) caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) impelled the author to gather the facts about the nature of this new pathogen. The aim of this paper was to discuss the mechanisms involved in the pathogenesis of neurological complications during the course of COVID-19.State of the art: Neurological symptoms, such as impairment of taste or smell, headache, nausea and/or altered consciousness, are commonly described in COVID-19 patients, although there are emerging clinical reports of more serious conditions such as acute cerebrovascular accidents, encephalitis and demyelinating disease. Whether these manifestations are the direct consequence of viral invasion of the central nervous system, or are caused by indirect mechanisms, is yet to be established. Studies to date have indicated that neurological lesions found in the brains of COVID-19 patients are a combination of direct cytopathic effects caused by SARS-CoV-2 replication and indirect effects due to hypoxia, excessive cytokine reaction, impairedimmune response, and cerebrovascular injury induced by viral infection. Studies are still pending into possible routes of SARS-CoV-2 neuroinvasion encompassing the haematopoietic pathway via the blood-brain barrier and retrograde axonal transport through the cranial nerves.Clinical implications: A thorough understanding of SARS-CoV-2 involvement in neurological complications is still lacking. However, our knowledge about SARS-CoV-2 virulence is rapidly expanding, and that has inclined the author to prepare this comprehensive review in the hope that it will improve understanding about the molecular mechanisms underlying neurological abnormalities associated with COVID-19.Future directions: A future detailed study should explore the diagnostics and disease mechanisms so as to enable the development of better therapeutic strategies to reduce the severity of COVID-19 neurological complications
Borna disease
Borna disease (the name stem from a small village in Saxony, Germany where the disease became epidemic in 1895) is caused by atypical virus (Borna disease virus, BDV). BDV is prototypic virus of the family Bornaviridae, within the order Mononegavirales within which viruses of Ebola and Mahrburg, an Rhabdoviridae are also classified. Noteworthy, all attempts to isolate BDV with methods of classical virology failed and the virus was only molecularly cloned in the late eighties of the XX century. BDV occur epidemically in Germany, Switzerland, North America, Japan and Israel. It seems that, analogously to rabies virus, it may infect all the vertebrates including horses, primates, ships, lamas, hippos, cats and cattle but also birds (ostrich). The virus reservoir are probably small rodents. The problem of BDV infection in humans is still open to debate.Choroba Borna (której nazwa pochodzi od małego miasta Borna w dolnej Saksonii, gdzie wystąpiła epidemia choroby w 1895 roku) wywoływana jest przez nietypowy wirus (Borna disease virus, BDV). BDV jest prototypowym wirusem rodziny Bornaviridae, w obrębie rzędu Mononegavirales, do którego należą także wirusy Ebola i Marburg oraz Rhabdoviridae. Warto podkreślić, że BDV próbowano latami wyizolować klasycznymi metodami wirusologii, bezskutecznie; udało się go sklonować metodami biologii molekularnej dopiero w końcu lat osiemdziesiątych XX wieku. BDV występuje endemicznie w Niemczech, Szwajcarii, Ameryce Północnej oraz części Azji (Japonia) i w Izraelu. Wydaje się, że podobnie jak wirus wścieklizny BDV może zakażać wszystkie ciepłokrwiste zwierzęta (konie, naczelne, owce, hipopotamy, lamy, koty i bydło), a także ptaki (strusie). Rezerwuarem BDV są prawdopodobnie małe gryzonie. Kwestia, czy u człowieka w ogóle występuje manifestujące się klinicznie zakażenie, jest nadal przedmiotem kontrowersji
Paramyxoviruses
We review here syndromes caused by viruses belonging to Paramyxoviridae family: mumps causing meningoencephalitis and, rarely, ADEM (acute disseminated encephalomyelitis) and measles. Neurological sequelae in the cause of measles comprise acute disseminated measles encephalitis (ADAM), measles inclusion-body encephalitis (MIBE), subacute sclerosing panencephalitis (SSPE) and post-infectious encephalitis (PIE). The sequence of those encephalitides following measles infection is as follows: acute measles encephalitis comes first, follows by MIBE (1-9 months) and SSPE (3-15 years). The measles encephalitis in the course of HIV infection is a separate phenomenon.W pracy omawiamy choroby układu nerwowego wywołane przez wirusy z rodziny Paramyxoviridae: świnkę będącą przyczyną zapalenia opon mózgowo-rdzeniowych i mózgu u dzieci i, w przebiegu AIDS, ADEM (acute disseminated encephalomyelitis) oraz odrę. Komplikacje neurologiczne w następstwie zakażenia wirusem odry występują pod postacią ostrego rozsianego zapalenia mózgu (ang. acute disseminated measles encephalitis, ADAM), wtrętowego zapalenia mózgu (ang. measles inclusion body encephalitis, MIBE), podostrego stwardniającego zapalenia mózgu (ang. subacute sclerosing panencephalitis, SSPE) oraz przyzakaźnego zapalenia mózgu (ang.post-infectious encephalitis, PIE). Obserwuje się typową sekwencję pojawiania się komplikacji neurologicznych: ostre zapalenie mózgu w przebiegu odry jest zjawiskiem rzadkim, natomiast pleocytoza w płynie mózgowo-rdzeniowym i zmiany w EEG są częste. PIE pojawia się w 7-14 dni po infekcji, MIBE - w 1-9 miesięcy, a SSPE - po upływie trzech, a nawet kilkunastu lat. Na odrębne omówienie zasługuje odrowe zapalenie mózgu w przebiegu AIDS
Herpesvirus
We review here infections of both peripheral and central nervous system caused by herpes viruses. To the most important entities one should classify: herpetic encephalitides caused by Herpes simplex virus type I and II, encephalitides caused by varicella-zoster virus, encephalitis in the course of infectious mononucleosis (the Epstein- Barr virus) and encephalitides caused by cytomegalia wirus and herpes B virus. In particular, we covered herpes viruses infections as complications of AIDS.W pracy omówiono zakażenia ośrodkowego i obwodowego układu nerwowego wywołane przez herpeswirusy. Do najważniejszych jednostek chorobowych należą: opryszczkowe zapalenie mózgu wywołane przez Herpes simplex virus typu 1. i 2., zapalenia mózgu wywołane przez wirus ospy wietrznej - półpaśca, półpasiec, zapalenie mózgu w przebiegu mononukleozy zapalnej, neuralgia postherpetyczna oraz zapalenia mózgu wywołane wirusem herpes typu B i cytomegalii. Zwrócono szczególną uwagę na herpesowe zapalenie mózgu w przebiegu AIDS
Rabies
Rabies is a fatal disease (50 000 death in the third Word countries) caused by a virus from a family Rhabdoviridae (from a Greek noun rhabdos – a rod). A virus, cause rabies, demonstrated a characteristic bullet-like shape. Human beings are infected by rabid animal bite (dogs or foxes); there is a possibility of infection through the aerosols in caves invested by carnivorous bats. The virus is ubiquitous; the exceptions are: Antarctic, the British Isles, Ireland, Island, New Zealand, Hawaii, Bahamas and Bermudas. In the Western countries and the USA, also in Poland, the prevalence of rabies is low (1 case in the USA in 1998 and 4 in 1997), but in countries like India or Mexico, the prevalence is in a range of 3.3/105 and thousand of deaths every year (mainly in India). About 50% of cases of rabies is diagnosed in boys under 15. Neuropathologic study reveals features of encephalitis; cytoplasmic Negri bodies are present within the neurons.Wścieklizna to śmiertelna choroba (rocznie około 50 000 zgonów w krajach Trzeciego Świata) wywoływana przez wirus z rodziny Rhabdoviridae (od greckiego rzeczownika rhabdos - pałeczka), o charakterystycznym wirionie (cząsteczce wirusa) w kształcie pocisku. Człowiek zakaża się zwykle od ugryzienia przez chorego psa lub zwierzęta dzikie (w Polsce lisy). Istnieje również możliwość zakażenia od zainfekowanych nietoperzy, wyjątkowo rzadko zakażenie następuje drogą kropelkową. Wirus występuje na całym świecie, z wyjątkiem Antarktyki oraz Wysp Brytyjskich, Irlandii, Islandii, Hawajów, Nowej Zelandii, wysp Bahama i Bermudów. W krajach Europy Zachodniej i USA, także w Polsce, częstość występowania wścieklizny jest bardzo mała (1 przypadek w USA w 1998 i 4 w 1997 roku), natomiast w krajach takich jak Indie czy Meksyk wynosi ona około 3,3/105, a każdego roku odnotowuje się w nich wiele tysięcy zgonów (głównie w Indiach) z powodu tej choroby. Około 50% przypadków wścieklizny rozpoznaje się u chłopców poniżej 15. roku życia. Badanie neuropatologiczne wykazuje cechy zapalenia mózgu, w neuronach obserwuje się cytoplazmatyczne ciała Negriego
Arboviruses
In this review we covered encephalitides and other sequelae of arbovirus infections. A family Flaviviridae along with families Togaviridae, Bunyaviridae, Reoviridae and Arenaviridae had been previously classified as Arboviridae (arthropod-borne). In spite of a significant diversity of viruses of the Arboviridae group, the term “arboviruses” is still useful and widely used. Here we covered viruses spread by ticks: tick-borne encephalitis virus, Powassan, Russian spring summer encephalitis virus, Kyasanur forest disease virus, Omsk hemorrhagic fever virus, louping ill and by mosquitos: yellow fever virus, Wesselsbron virus, Ilheus virus, Japanese B encephalitis virus, Murray Valley encephalitis virus, St. Louis encephalitis virus, West Nile virus and Dengue hemorrhagic fever virus as well as a Modoc group. Togaviruses comprise Eastern, Western and Venezuelan equine encephalitis virus while fleboviruses, Rift Valley virus. Coltiviruses comprise Colorado thick fever virus.W pracy omówiono powikłania ze strony układu nerwowego po zakażeniu arbowirusami. Rodzina Flaviviridae dawniej była zaklasyfikowana, wraz z rodzinami Togaviridae, Bunyaviridae, Reoviridae i Arenaviridae, do grupy zwanej Arboviridae. Grupa ta obejmowała wirusy przenoszone przez stawonogi (arthropod-borne). Pomimo dużego zróżnicowania wirusów należących do grupy Arboviridae określenie „arbowirusy” jest nadal przydatne i często stosowane. Omówiono wirusy przenoszone przez kleszcze: wirusy kleszczowego zapalenia mózgu, Powassan, rosyjskiego wiosenno-letniego zapalenia mózgu, choroby lasu Kyasanur, omskiej gorączki krwotocznej, louping ill („skaczących” owiec) oraz wirusy przenoszone przez komary: grupę żółtej gorączki, wirus Wesselsbron, Ilheus i Rocio, grupę japońskiego zapalenia mózgu, wirus zapalenia mózgu doliny Murray, wirus zapalenia mózgu St. Louis, wirus zachodniego Nilu, wirus gorączki krwotocznej dengi i grupę Modoc. Do omówionych togawirusów należą: wirusy wschodniego, zachodniego i wenezuelskiego końskiego zapalenia mózgu. Do rodzaju Bunyavirus należą: grupa Modoc i wirus gorączki doliny Rift; do koltiwirusów: wirus gorączki kleszczowej Kolorado