83 research outputs found
Neuroimmunopathology in Toxoplasmic Encephalitis
Toxoplasma gondii is a zoonotic protozoan parasite that causes mortality because of significant neuropathology. It is widespread in neonatal infections. Although the neuroimmunopathogenesis of toxoplasmic encephalitis (TE) has been studied for many years, it is still not completely understood, showing the diseaseâs severity. The urge to write this chapter comes at this stage. The sections covered in this chapter show the pathogenesis that has been established and characterized so far. The involvement of astrocytes and microglia in the development of neuropathology, which begins with tachyzoites crossing the blood-brain barrier during acute infection, has been explored. The molecular mechanism between schizophrenia and TE has been thoroughly proven. Uncovering the molecular pathogenesis of TE is critical for both understanding neuropathology and elucidating the link between neuropsychiatric diseases. Each part covered here is expected to contribute to developing novel therapeutic agents for the treatment and maybe prevention of neuropathology. The pathogenesis of the steady progression of encephalitis has been meticulously revealed. Thus, this chapter will offer significant insight into developing novel treatments for all organisms suffering from this disease
Molecular profiling and antimicrobial resistance of Shiga toxin-producing Escherichia coli O26, O45, O103, O121, O145 and O157 isolates from cattle on cow-calf operations in South Africa
In this study, 140 cattle STEC isolates belonging to serogroups O157, O26, O145, O121, O103 and O45
were characterized for 38 virulence-associated genes, antimicrobial resistance profiles and genotyped
by PFGE. The majority of isolates carried both stx1 and stx2 concurrently, stx2c, and stx2d; plasmidencoded
genes ehxA, espP, subA and saa but lacked katP and etpD and eaeA. Possession of eaeA was
significantly associated with the presence of nle genes, katP, etpD, ureC and terC. However, saa and
subA, stx1c and stx1d were only detected in eaeA negative isolates. A complete OI-122 and most non-
LEE effector genes were detected in only two eaeA positive serotypes, including STEC O157:H7 and
O103:H2. The eaeA gene was detected in STEC serotypes that are commonly implicated in severe
humans disease and outbreaks including STEC O157:H7, STEC O145:H28 and O103:H2. PFGE revealed
that the isolates were highly diverse with very low rates of antimicrobial resistance. In conclusion, only
a small number of cattle STEC serotypes that possessed eaeA, had the highest number of virulenceassociated
genes, indicative of their high virulence. Further characterization of STEC O157:H7, STEC
O145:H28 and O103:H2 using whole genome sequencing will be needed to fully understand their
virulence potential for humans.This manuscript is part a
dissertation submitted in the Veterinary Public Health section, Department of Paraclinical Sciences, University
of Pretoria, in partial fulfilment of the requirements for the degree of Master of Science (Veterinary Science). (http://hdl.handle.net/2263/65499)The Gauteng Department of Agriculture and Rural Development (GDARD) (Grant
No. FY 2013/14âA0W907), the Global Disease Detection (GDD) Program of the Centers for Disease Control
and Prevention (CDC) (Grant No. 1U2GGH001874â01) and the National Research Foundation (NRF) of South
Africa Thuthuka (TTK13062619943), Research Technology (RTF14012762427) Funds.https://www.nature.com/srepam2019Paraclinical Science
Compositions and methods of enhancing immune responses to Eimeria
Vaccines comprising TRAP polypeptides and Salmonella enteritidis vectors comprising TRAP polypeptides are provided. The vaccines may also include a CD154 polypeptide capable of binding to CD40. Also provided are methods of enhancing an immune response against Apicomplexan parasites and methods of reducing morbidity associated with infection with Apicomplexan parasites
Compositions and methods of enhancing immune responses to Eimeria
Vaccines comprising TRAP polypeptides and Salmonella enteritidis vectors comprising TRAP polypeptides are provided. The vaccines may also include a CD154 polypeptide capable of binding to CD40. Also provided are methods of enhancing an immune response against Apicomplexan parasites and methods of reducing morbidity associated with infection with Apicomplexan parasites
Evolution and antimicrobial resistance of enterococci isolated from Pecorino and goat cheese manufactured on-farm in an area facing constraints as per EU Regulation 1305/2013 in Umbria, Italy
The latest EU regulation on geographical indications (EU Regulation No. 1151/2012) has introduced a set of new tools for the protection and enhancement of food products in rural areas, under the group name of optional quality term (OQT). The Commission Delegated EU Regulation, No. 665/2014, regulated the conditions for the use of the optional quality term mountain product (MP), to support the implementation of a mountain value chain. This new tool is aimed at promoting local development, maintaining the economic activities in mountain areas, and redistributing wealth, whilst, at the same time, promoting the territory. Pecorino and goat cheeses are typical Italian cheeses made usually with whole raw eweâs or raw goatâs milk, without starter culture addition. In an attempt to characterize these productions, the aim of this study was to investigate the evolution of enterococci during the production and ripening of Pecorino cheese made in three different farms, located in Umbria, Italy in areas facing natural or other specific constraints as stipulated by Regulation 1305/2013 on support for rural development by the European Agricultural Fund for Rural Development (EAFRD). Enterococci are enteric organisms which are commonly isolated from ewe and goatâs milk production in Umbria, Italy. Counts of enterococci in raw milk ranged from 1.75 for ovine milk to 3.62 for ewe milk and a marked reduction was observed after thermization especially in ovine milk. Out of 100 isolates, 69 were E. faecium, 23 E. durans, 8 E. faecalis and 2 E. casseliflavus and the distribution of species between farms and between samples showed a prevalence of E. faecium in ovine farms and E. durans in ewes farms, with an equal distribution between samples. High percentages of susceptible isolates were found for amoxicillin/clavulanic acid, ampicillin, chloramphenicol, sulphamethoxazole, sulphamethoxazole/trimethoprim, ticarcillin, vancomycin. A high prevalence of resistant strains (>30%) was observed for amikacin, ciprofloxacin, ceftriaxone, kanamycin, tetracycline. A comparison of this results with those of previous works on similar dairy products revealed high levels of resistance to antimicrobials which needs to be addressed.European Food Safety Authority (EFSA).https://www.pagepressjournals.org/index.php/ijfsam2023Paraclinical Science
Two screening assays to detect vancomycin-resistant Enterococcus spp.
Enterococci have become major nosocomial pathogens. An increasing number of these
infections are as a result of vancomycin-resistant enterococci. Accurate detection of vancomycinresistant
enterococci (VRE) is important, so that appropriate therapy and infection control measures
may be instituted, including veterinary surveillance. Two screening assays to detect vancomycin
resistance in enterococci are proposed. Barnes Basal Medium agar (Ba) and Brain Heart Infusion (BHI)
broth (plus 1% TTC-2,3,5-triphenyltetrazolium chloride) with several concentrations of vancomycin
were used in this work. Five Enterococcus casseliflavus strains with low-level resistance to vancomycin
(4 g/mL) were used. Both media were able to quickly detect the breakpoint of the vancomycinresistant
strains used in this work, and also provided insight into the dynamics of the antibiotic effect
at a low concentration on the tested bacterial suspensions.European Food Safety Authority (EFSA).https://www.mdpi.com/journal/microbiolresam2023Paraclinical Science
Time-delayed effects of a single application of AgNPs on structure of testes and functions in Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae)
Silver nanoparticles (AgNPs) are currently themost frequently used engineered nanoparticles. The penetration of
AgNPs into ecosystems is undeniable, and their adverse effects on organismreproduction are of fundamental importance
for ecosystem stability. In this study, the survival time of the Egyptian beetle Blaps polychresta Forskal,
1775 (Coleoptera: Tenebrionidae), after a single application of 7 different doses,was calculated for 30 days. Then,
for the group for which the effect on mortality was calculated as LOAEL - the Lowest Observed Adverse Effect
Level, namely, 0.03 mg AgNPs/g body weight (b.w.t.), the following were assessed: structure and ultrastructure
of gonads by TEM and SEM, cell viability by cytometry, DNA damage by the comet assay, and a variety of stress
markers by spectrophotometric methods. A dose-dependent reduction in the survival time of the insects wa
Metabolomic analysis reveals spermatozoa and seminal plasma differences between Duroc and Liang guang Small-spotted pig
The Liang guang Small-spotted pig is a well-known Chinese indigenous pig that is valued for its exceptional meat quality. However, the Liang guang Small-spotted pig has a lower semen storage capacity, shorter storage time and worse semen quality compared to Duroc. Pig sperm used for artificial insemination (AI) loses part of vitality and quality when being stored in commercial solutions. Serious vitality losses and short shelf life of the semen are particularly prominent in Liang guang Small-spotted pig. In this study, the metabolites in seminal plasma and spermatozoa of Duroc and Liang guang Small-spotted pigs were identified using UHPLCâQ-TOF/MS technology. The findings indicated forty distinct metabolites concentrating on energy metabolic substrates and antioxidant capacity in Liang guang Small-spotted pig and Duroc seminal plasma, including D-Fructose, succinate, 2-dehydro-3-deoxy-d-gluconate, alanine betaine, citrate, carnitine, acetylcarnitine and so on. Seventeen different metabolites were explored, with a focus on glycerophospholipid metabolism in Liang guang Small-spotted pig and Duroc spermatozoa, primarily including glycerol 3-phosphate, acetylcarnitine, phosphatidylcholine (PC) 16:0/16:0, palmitoyl sphingomyelin, acetylcholine, choline, glycerophosphocholine, betaine, L-carnitine, creatinine and others. This study reveals the metabolite profile of spermatozoa and seminal plasma among different pig breeds and might be valuable for understanding the mechanisms that lead to sperm storage capacity. Metabolites involved in energy metabolism, antioxidant capacity and glycerophospholipid metabolism might be key to the poor sperm storage capacity in Liang guang Small-spotted pig
Hygienic characteristics and detection of antibiotic resistance genes in crickets (Acheta domesticus) breed for flour production
During the last ten years, the worldwide interest in using insects as food and feed has
surged. Edible insects fall within the category of novel foods, i.e., the category of food not consumed
in significant amounts in the European Union before 15 May 1997 (the date of entry into force of
Regulation (EC) No. 258/1997, later repealed by Regulation (EU) No. 2283/2015). One of the most
promising insect species to be raised for food is the house cricket (Acheta domesticus). In this study,
the rearing of a stock of house crickets was studied over a period of four months. The microbiological
quality of the farm was studied using swabs on the surface of the rearing boxes to analyze the
trend over time of different populations of microorganisms (total aerobic mesophilic microbiota,
Lactobacillus spp., enterococci, Staphylococcus spp., Enterobacteriaceae, total coliforms, Pseudomonas
spp. and molds). The presence of four antimicrobial resistance genes (aph, blaZ, sul1, and tetM) was
investigated by polymerase chain reaction. A production scheme was also developed in order to
obtain a cricket-based flour, which was analyzed for its microbiological and chemical-centesimal
profile. The results obtained in this study demonstrate that the contamination increases with time
and that a proper management of the farming system for insects is of the utmost importance, as it is
for conventional farm animals such as ungulates, poultry, and rabbits. The old-fashioned adage âall
full, all emptyâ for the farming system summarizes the need for proper cleaning and disinfection of
the structures at the end of each production cycle.European Food Safety Authority (EFSA)https://www.mdpi.com/journal/microbiolresam2022Paraclinical Science
Virulence characteristics and antimicrobial resistance profiles of Shiga toxin-producing escherichia coli isolates from humans in South Africa : 2006â2013
Shiga toxin-producing Escherichia coli (STEC) isolates (N = 38) that were incriminated in
human disease from 2006 to 2013 in South Africa were characterized by serotype, virulence-associated
genes, antimicrobial resistance and pulsed-field gel electrophoresis (PFGE). The isolates belonged
to 11 O:H serotypes. STEC O26:H11 (24%) was the most frequent serotype associated with human
disease, followed by O111:H8 (16%), O157:H7 (13%) and O117:H7 (13%). The majority of isolates were
positive for key virulence-associated genes including stx1 (84%), eaeA (61%), ehxA (68.4%) and espP
(55%), but lacked stx2 (29%), katP (42%), etpD (16%), saa (16%) and subA (3%). stx2 positive isolates
carried stx2c (26%) and/or stx2d (26%) subtypes. All pathogenicity island encoded virulence marker
genes were detected in all (100%) isolates except nleA (47%), nleC (84%) and nleD (76%). Multidrug
resistance was observed in 89% of isolates. PFGE revealed 34 profiles with eight distinct clusters that
shared 80% intra-serotype similarity, regardless of the year of isolation. In conclusion, STEC isolates
that were implicated in human disease between 2006 and 2013 in South Africa were mainly non-O157
strains which possessed virulence genes and markers commonly associated with STEC strains that
have been incriminated in mild to severe human disease worldwide. Improved STEC monitoring and
surveillance programs are needed in South Africa to control and prevent STEC disease in humans.The National Research Foundation (NRF) of South Africa: Thuthuka (TTK13062619943),
Research Technology Fund (RTF14012762427), the Gauteng Department of Agriculture and Rural Development
(GDARD Grants-2013-2015) and the South African Medical Research Council (Self-Initiated Research 2017-2019).https://www.mdpi.com/journal/toxinsam2019Paraclinical Science
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