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1.
Microbiol Spectr ; 12(4): e0325823, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38421193

RESUMO

The growing emergence of resistance to current anti-theilerial agents necessitates the exploration of alternative approaches to drug discovery. This study evaluated the antiparasitic efficacy of 148 compounds derived from an epigenetic inhibitor library against the schizont stage of a Theileria annulata-infected cell line. Initial screening at a concentration of 10 µM identified 27 compounds exhibiting promising anti-theilerial activity. Further investigation, including determination of the 50% inhibitory concentration (IC50) and host cell cytotoxicity assay, highlighted seven highly effective compounds (SAHA, BVT-948, Trichostatin A, Methylstat, Plumbagin, Ryuvidine, and TCE-5003) against T. annulata-infected cells. Analysis of the active compounds revealed their inhibitory action against various human targets, such as HDAC (SAHA and Trichostatin A), SET domain (Ryuvidine), PRMT (BVT-948 and TCE-5003), histone demethylase (Methylstat), and ROS/apoptosis inducer (Plumbagin). We identified gene orthologs of these targets in Theileria and conducted molecular docking studies, demonstrating effective binding of the compounds with their respective targets in the parasite, supported by in vitro data. Additionally, we performed in silico ADME/T predictions, which indicated potential mutagenic and hepatotoxic effects of Plumbagin, Methylstat, and TCE-5003, rendering them unsuitable for drug development. Conversely, SAHA, Trichostatin A, and BVT-948 showed promising characteristics and may represent potential candidates for future development as chemotherapeutic agents against tropical theileriosis. These findings provide valuable insights into the search for novel anti-theilerial drugs and offer a basis for further research in this area.IMPORTANCETheileria annulata is a protozoan parasite responsible for tropical theileriosis, a devastating disease affecting cattle. Traditional chemotherapy has limitations, and the study explores the potential of epidrugs as an alternative treatment approach. Epidrugs are compounds that modify gene expression without altering the underlying DNA sequence, offering a novel way to combat parasitic infections. This research is pivotal as it addresses the urgent need for innovative therapies against T. annulata, contributing to the development of more effective and targeted treatments for infected livestock. Successful implementation of epidrugs could not only enhance the well-being of cattle but also have broader implications for the control of parasitic diseases, showcasing the paper's significance in advancing veterinary science and improving livestock health globally.


Assuntos
Doenças dos Bovinos , Ácidos Hidroxâmicos , Naftalenos , Naftoquinonas , Parasitos , Theileria annulata , Theileriose , Humanos , Animais , Bovinos , Theileria annulata/química , Theileria annulata/genética , Theileria annulata/metabolismo , Theileriose/tratamento farmacológico , Theileriose/parasitologia , Simulação de Acoplamento Molecular , Esquizontes/química , Doenças dos Bovinos/prevenção & controle
2.
Colloids Surf B Biointerfaces ; 231: 113531, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37742363

RESUMO

Bacterial infections are considered as one of the major health threats to the global population. The advent of bacterial species with antibiotic resistance has attracted significant efforts to develop novel materials and strategies to effectively avoid the resistance with enhanced antibacterial potential. In this work, we have developed oxidase-mimetic cerium oxide nanoparticles (CeO2 NPs), which exhibit nanozyme activity at physiological pH in the presence of adenosine triphosphate (ATP). The oxidase-mimetic activity was confirmed to involve superoxide radicals using p-benzoquinone and dihydroethidium. Using indole propionic acid, ethanol, and terephthalic acid, it was confirmed that the oxidase-mimetic activity of CeO2 NPs with ATP does not involve the formation of hydroxyl radicals. CeO2 NPs with ATP produced a strong antibacterial activity against Staphylococcus aureus and Escherichia coli within 3 - 6 hrs. The bacterial cell morphology analysis suggested that superoxide radicals generated during the oxidase-mimetic activity of CeO2 NPs with ATP cause distortion of paired and tetrad arrangement (Staphylococcus aureus), loss of cytoplasmic content, damage, and pore formation in the cell wall (Escherichia coli) that led to the death of bacteria. Further, the live/dead assay also concludes the time-dependent death of bacterial cells with the highest death in the cell population exposed to CeO2 NPs and ATP. Thus, the antibacterial activity at physiological pH by superoxide radical generating oxidase-mimetic CeO2 NPs could be further extended to other pathogenic bacterial species.


Assuntos
Cério , Nanopartículas Metálicas , Nanopartículas , Superóxidos , Oxirredutases/metabolismo , Trifosfato de Adenosina/metabolismo , Nanopartículas/química , Cério/farmacologia , Cério/química , Escherichia coli/metabolismo , Bactérias/metabolismo , Antibacterianos/química , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química
3.
Cell Commun Signal ; 21(1): 78, 2023 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-37069625

RESUMO

BACKGROUND: Bovine theileriosis caused by the eukaryotic parasite Theileria annulata is an economically important tick-borne disease. If it is not treated promptly, this lymphoproliferative disease has a significant fatality rate. Buparvaquone (BPQ) is the only chemotherapy-based treatment available right now. However, with the emergence of BPQ resistance on the rise and no backup therapy available, it is critical to identify imperative drugs and new targets against Theileria parasites. METHODS: Artemisinin and its derivatives artesunate (ARS), artemether (ARM), or dihydroartemisinin (DHART) are the primary defence line against malaria parasites. This study has analysed artemisinin and its derivatives for their anti-Theilerial activity and mechanism of action. RESULTS: ARS and DHART showed potent activity against the Theileria-infected cells. BPQ in combination with ARS or DHART showed a synergistic effect. The compounds act specifically on the parasitised cells and have minimal cytotoxicity against the uninfected host cells. Treatment with ARS or DHART induces ROS-mediated oxidative DNA damage leading to cell death. Further blocking intracellular ROS by its scavengers antagonised the anti-parasitic activity of the compounds. Increased ROS production induces oxidative stress and DNA damage causing p53 activation followed by caspase-dependent apoptosis in the Theileria-infected cells. CONCLUSIONS: Our findings give unique insights into the previously unknown molecular pathways underpinning the anti-Theilerial action of artemisinin derivatives, which may aid in formulating new therapies against this deadly parasite. Video abstract.


Assuntos
Artemisininas , Theileria annulata , Animais , Bovinos , Theileria annulata/genética , Caspases , Espécies Reativas de Oxigênio , Artemisininas/farmacologia , Artesunato , Apoptose , Dano ao DNA , Estresse Oxidativo
4.
Pathogens ; 12(2)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36839568

RESUMO

Accurate quantification based on nucleic acid amplification is necessary to avoid the spread of pathogens, making early diagnosis essential. Droplet digital PCR (ddPCR) stands out for absolute parasite quantification because it combines microfluidics with the TaqMan test. This helps deliver maximum accuracy without needing a reference curve. This study assessed the efficacy of ddPCR as a detection tool for the bovine theileriosis (BT) caused by Theileria parasites. We developed and validated a duplex ddPCR method that detects and quantifies the Theileria genus (18S rRNA) and identifies clinically significant Theileria annulata parasites (TaSP) in experimental and clinical samples. ddPCR was shown to be as effective as qPCR throughout a 10-fold sample dilution range. However, ddPCR was more sensitive than qPCR at lower parasite DNA concentrations and reliably assessed up to 8.5 copies/µL of the TaSP gene in the infected DNA (0.01 ng) samples. The ddPCR was very accurate and reproducible, and it could follow therapeutic success in clinical cases of theileriosis. In conclusion, our ddPCR assays were highly sensitive and precise, providing a valuable resource for the study of absolute parasite quantification, drug treatment monitoring, epidemiological research, large-scale screening, and the identification of asymptomatic parasite reservoirs in the pursuit of BT eradication.

5.
Microorganisms ; 10(4)2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35456882

RESUMO

Staphylococcus aureus is an opportunistic bacterium known to cause severe infections in humans and animals. It is one of the major bacteria causing subclinical and clinical mastitis, leading to significant economic losses in livestock industry. In this study, we have isolated and characterized 80 S. aureus clinical isolates from mastitis-infected animals. The analysis of antimicrobial susceptibility, molecular typing, biofilm production and genetic determinants was performed to understand molecular and phenotypic features of the prevalent pathogen. Our antibiotic susceptibility assays showed the majority (57.5%) of isolates to be multidrug-resistant (MDR), 38.75% resistant and 3.75% sensitive. We found 25% isolates to be methicillin-resistant S. aureus (MRSA) based on oxacillin susceptibility assays. In the MRSA group, maximum isolates (95%) were MDR compared to 45% in MSSA. Multilocus sequence typing (MLST) revealed 15 different STs; ST-97 was the most common ST, followed by ST-2459, ST-1, ST-9 and ST-72. The agr typing showed agr-I as the most common type, followed by type II and III. Most isolates developed biofilms, which ranged in intensity from strong to weak. The presence or absence of lukS, a virulence-related gene, was found to have a substantial relationship with the biofilm phenotype. However, no significant association was found between biofilm formation and antimicrobial resistance or other virulence genes. We also found four MRSA isolates that were mecA negative based on molecular assays. Our findings reveal the prevalence of multidrug-resistant S. aureus clinical isolates in India that are biofilm positive and have critical genetic factors for disease pathogenesis causing bovine mastitis. This study emphasizes the need for the comprehensive surveillance of S. aureus and other mastitis-causing pathogens to control the disease effectively.

6.
Front Microbiol ; 12: 759817, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34867888

RESUMO

The apicomplexan parasite, Theileria annulata, is the most prevalent hemoprotozoan in livestock, causing significant economic losses worldwide. It is essential to develop new and improved therapeutics, as current control measures are compromised by the development of resistance against the only available antitheilerial drug, buparvaquone (BPQ). Histone deacetylase inhibitors (HDACi) were shown to treat cancer effectively and revealed in vitro antiparasitic activity against apicomplexan parasites such as Plasmodium and Toxoplasma. In this study, we investigated the antitheilerial activity of the four anti-cancer HDACi (vorinostat, romidepsin, belinostat, and panobinostat) against the schizont stage of T. annulata parasites. All four HDACi showed potent activity and increased hyperacetylation of the histone-4 protein. However, based on the low host cell cytotoxicity and IC50 values, vorinostat (0.103 µM) and belinostat (0.069 µM) were the most effective showing antiparasitic activity. The parasite-specific activities of the HDACi (vorinostat and belinostat) were evaluated by western blotting using parasite-specific antibodies and in silico analysis. Both vorinostat and belinostat reduced the Theileria infected cell viability by downregulating anti-apoptotic proteins and mitochondrial dysfunction, leading to caspase-dependent cell apoptosis. The HDACi caused irreversible and antiproliferative effects on the Theileria infected cell lines. Our results collectively showed that vorinostat and belinostat could be used as an alternative therapy for treating Theileria parasites.

8.
Front Microbiol ; 11: 579929, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33552006

RESUMO

Background: Apicomplexan parasite Theileria annulata causes significant economic loss to the livestock industry in India and other tropical countries. In India, parasite control is mainly dependent on the live attenuated schizont vaccine and the drug buparvaquone. For effective disease control, it is essential to study the population structure and genetic diversity of the Theileria annulata field isolates and vaccine currently used in India. Methodology/Results: A total of 125 T. annulata isolates were genotyped using 10 microsatellite markers from four states belonging to different geographical locations of India. Limited genetic diversity was observed in the vaccine isolates when compared to the parasites in the field; a level of geographical substructuring was evident in India. The number of genotypes observed per infection was highest in India when compared to other endemic countries, suggesting high transmission intensity and abundance of ticks in the country. A reduced panel of four markers can be used for future studies in these for surveillance of the T. annulata parasites in India. Conclusion: High genetic variation between the parasite populations in the country suggests their successful spread in the field and could hamper the disease control programs. Our findings provide the baseline data for the diversity and population structure of T. annulata parasites from India. The low diversity in the vaccine advocates improving the current vaccine, possibly by increasing its heterozygosity. The reduced panel of the markers identified in this study will be helpful in monitoring parasite and its reintroduction after Theileria eradication.

9.
Sci Rep ; 9(1): 16028, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690794

RESUMO

Methicillin-Resistant Staphylococcus aureus (MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of S. aureus causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive S. aureus (MSSA, n = 48) and oxacillin susceptible mecA positive S. aureus (OS-MRSA, n = 11) based on oxacillin susceptibility, mecA gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of fem XAB gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the fem XAB genes revealed mutations in fem × (K3R, H11N, N18H and I51V) and fem B (L410F) genes. The fem XAB genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.


Assuntos
Proteínas de Bactérias/genética , Biofilmes , Staphylococcus aureus Resistente à Meticilina/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Regulação para Baixo , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/fisiologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fenótipo , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia
10.
Front Physiol ; 10: 673, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31231237

RESUMO

Tropical theileriosis caused by Theileria annulata infection is a significant livestock disease affecting cattle health and productivity resulting in substantial monetary losses in several countries. Despite the use of an effective vaccine for disease control still, a high incidence of infection is reported from India. One of the many reasons behind the ineffective disease control can be the existence of genetically diverse T. annulata parasite population in India. Therefore, studies focusing on understanding the genotypes are warranted. In this study, we have performed a genetic analysis of the Indian T. annulata field cell lines and the vaccine line using microsatellite markers, Genotyping based sequencing (GBS) and tams1 gene polymorphism. The degree of allelic diversity and multiplicity of the infection was determined to be high in the Indian population. No geographical sub-structuring and linkage disequilibrium were observed in the population. High population diversity was found which were similar with countries like Oman, Tunisia, and Turkey in contrast to Portugal and China. The presence of multiple genotypes as determined by microsatellite marker genotyping, GBS analysis and tams1 gene polymorphism point toward a panmictic parasite population in India. These findings are the first report from India which would help in understanding the evolution and diversity of the T. annulata population in the country and can help in designing more effective strategies for controlling the disease.

11.
Biosens Bioelectron ; 133: 24-31, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30903938

RESUMO

Chemiresistive platforms are best suited for developing DNA hybridization detection systems, owing to their ease of fabrication, simple detection methodology and amenability towards electronics. In this work, we report development of a generic, robust, electrospun nanofiber based interdigitated chemiresistive platform for DNA hybridization detection. The platform comprises of interdigitated metal electrodes decorated with electrospun nanofibers on the top. Two approaches viz., drop casting of graphene doped Mn2O3 nanofibers (GMnO) and direct electrospinning of polyaniline/polyethylene oxide (PANi/PEO) composite nanofibers, have been utilized to decorate these electrodes. In both approaches, inter-device variability, a key challenge for converting this proof-of-concept into a tangible prototype/product, has been addressed using a shadow masking technique. Consequently, the relative standard deviation for multiple PANi/PEO nanofiber based chemiresistors has been brought down from 17.82% (without shadow masking) to 4.41% (with shadow masking). The nanofibers are further modified with single-stranded probe DNAs, to capture a desired hybridization event. To establish the generic nature of the platform, detection of multiple target DNAs has been successfully demonstrated. These targets include dengue virus specific consensus primer (DENVCP) and four DNAs corresponding to Staphylococcus aureus specific genes, namely nuc, mecA, vanA and protein A. The chemiresistive detection of DENVCP has been performed in the concentration range of 10 fM - 1 µM, whereas the detection of the other targets has been carried out in the range of 1 pM - 1 µM. Using a 3σ method, we have estimated the limit of detection for the chemiresistive detection of DENVCP to be 1.9 fM.


Assuntos
Técnicas Biossensoriais , DNA de Cadeia Simples/química , DNA/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Carbono-Oxigênio Ligases/genética , Carbono-Oxigênio Ligases/isolamento & purificação , DNA/química , DNA de Cadeia Simples/genética , Grafite/química , Humanos , Nuclease do Micrococo/genética , Nuclease do Micrococo/isolamento & purificação , Nanofibras/química , Hibridização de Ácido Nucleico , Proteínas de Ligação às Penicilinas/isolamento & purificação , Proteína Estafilocócica A/genética , Proteína Estafilocócica A/isolamento & purificação , Staphylococcus aureus/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-30406042

RESUMO

There has been an alarming increase in infections caused by antimicrobial-resistant pathogens. These infections are responsible for more than half a million deaths globally each year. Staphylococcus aureus is one of the deadliest bacterial pathogen responsible for nosocomial and community acquired infections. The open-access Pathogen Box (PBox) provides a potential platform to identify new treatment options against antibiotic-resistant bacteria by repurposing it. In this study, we have screened the PBox library comprised of ~400 compounds to identify novel anti-staphylococcal compounds. in vitro antimicrobial screening using S. aureus isolates, ATCC 29213 (methicillin-sensitive) and ATCC 700699 (methicillin-resistant) revealed 13 compounds which showed highly potent antibacterial activity against both planktonic and biofilm state. The 13 compounds were not found cytotoxic to mouse macrophage cell line, RAW264.7. Out of the 13 compounds, only MMV687251 and MMV676477 revealed structural similarity with vancomycin by comparing their atomic pair fingerprints using Tanimoto coefficient method. The structural similarities may indicate similar mode of action like vancomycin for the two compounds. Our result showed that PBox compounds offer a promising lead for the development of new anti-staphylococcal treatment options.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Reposicionamento de Medicamentos , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7/efeitos dos fármacos
13.
Sci Rep ; 8(1): 15441, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30337565

RESUMO

Theileria annulata is an intracellular parasite that causes active and latent forms of bovine theileriosis. Diagnosis of the disease is primarily based on traditional methods such as microscopy, however, PCR based methods have proven to be superior in the absence of clear disease symptoms. However, diagnosis is difficult in cases of lower parasitaemia by conventional PCR. Hence, a rapid and sensitive method which can detect early infection and low parasite load is required. Therefore, we have developed an absolute quantification based real-time PCR (qPCR) assay. Reference standard curve using recombinant plasmids of a host (hprt) and a parasite gene (tasp) was constructed, and the assay was initially standardised using in vitro T. annulata cell lines. Further, 414 blood samples from suspected theileriosis cases were also evaluated using qPCR. The assay can estimate host to parasite ratios, calculate parasitaemia and treatment effectiveness in the clinical cases of theileriosis. In comparison with the conventional PCR results, 44 additional positive cases were found. Therefore, the assay holds importance in a clinical setting due to its ability to quantify the parasite load in clinical samples. It may be further used in distinguishing active and latent theileriosis infections and detection of drug resistance in the field.


Assuntos
Bovinos/parasitologia , Interações Hospedeiro-Parasita/genética , Parasitemia/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Linfócitos T/parasitologia , Theileria annulata/genética , Theileriose/parasitologia , Animais , Células Cultivadas , Carga Parasitária , Parasitemia/parasitologia , Theileria annulata/isolamento & purificação , Theileriose/epidemiologia
14.
Sci Rep ; 8(1): 8050, 2018 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-29795120

RESUMO

Multidrug-resistant pathogens causing nosocomial and community acquired infections delineate a significant threat to public health. It had urged to identify new antimicrobials and thus, generated interest in studying macrocyclic metal complex, which has been studied in the past for their antimicrobial activity. Hence, in the present study, we have evaluated the antimicrobial activity of the hexadentated macrocyclic complex of copper (II) (Cu Complex) derived from thiosemicarbazide against Gram-positive and Gram-negative bacteria. We observed increased susceptibility against standard isolates of Staphylococcus aureus with a minimum inhibitory concentration (MIC) range of 6.25 to 12.5 µg/mL. Similar activity was also observed towards methicillin resistant and sensitive clinical isolates of S. aureus from human (n = 20) and animal (n = 20) infections. The compound has rapid bactericidal activity, and we did not observe any resistant mutant of S. aureus. The compound also exhibited antibiofilm activity and was able to disrupt pre-formed biofilms. Cu complex showed increased susceptibility towards intracellular S. aureus and was able to reduce more than 95% of the bacterial load at 10 µg/mL. Overall, our results suggest that Cu complex with its potent anti-microbial and anti-biofilm activity can be used to treat MRSA infections and evaluated further clinically.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cobre/farmacologia , Compostos Organometálicos/farmacologia , Semicarbazidas/química , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Animais , Permeabilidade da Membrana Celular , Proliferação de Células , Células Cultivadas , Humanos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia
15.
Front Immunol ; 8: 1261, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29081773

RESUMO

Plasmodium, Toxoplasma, Cryptosporidium, Babesia, and Theileria are the major apicomplexan parasites affecting humans or animals worldwide. These pathogens represent an excellent example of host manipulators who can overturn host signaling pathways for their survival. They infect different types of host cells and take charge of the host machinery to gain nutrients and prevent itself from host attack. The mechanisms by which these pathogens modulate the host signaling pathways are well studied for Plasmodium, Toxoplasma, Cryptosporidium, and Theileria, except for limited studies on Babesia. Theileria is a unique pathogen taking into account the way it modulates host cell transformation, resulting in its clonal expansion. These parasites majorly modulate similar host signaling pathways, however, the disease outcome and effect is different among them. In this review, we discuss the approaches of these apicomplexan to manipulate the host-parasite clearance pathways during infection, invasion, survival, and egress.

16.
Front Microbiol ; 8: 1446, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28824577

RESUMO

Methicillin resistant Staphylococcus aureus causing bovine mastitis has been very well investigated worldwide. However, there are only limited reports on the characterization of methicillin resistant and sensitive coagulase negative staphylococci (CoNS) across the globe. Hence, in the present study, we aim to determine the phenotypic traits based on antimicrobial susceptibility profile and genotypic characterization by verifying the presence of resistance determinants, virulence and toxin genes present in the CoNS causing clinical mastitis. We obtained 62 CoNS isolates from 167 mastitic milk samples collected from three different states of India. The 62 isolates comprises of 10 different CoNS species S. sciuri, S. haemolyticus, S. chromogenes, S. saprophyticus, S. xylosus, S. simulans, S. agnetis, S. epidermidis, S. gallinarum, and S. cohinii. Susceptibility screening against 11 antibiotics determined 45.16% isolates as multidrug resistant (resistant to more than two class of antibiotic), 46.74% resistant (one or two antibiotic class) and 8.06% isolates were pan-sensitive (sensitive to all drugs). High resistance was observed against oxacillin and cefoxitin, whereas all isolates were susceptible toward vancomycin and linezolid. Fifty three isolates were methicillin resistant and 9 isolates were sensitive as determined by oxacillin susceptibility assay. The methicillin resistance gene, mecA was found in 95.16% isolates and staphylococcal cassette chromosome mec (SCCmec) typing predominantly revealed Type III (n = 34) and Type V (n = 18). Interestingly, 11.9% of mecA positive isolates were oxacillin susceptible and referred as oxacillin susceptible mecA positive staphylococci (OS-MRS). Additionally, genes encoding for enterotoxin, (sea, seb, seh, see) toxic shock syndrome (tsst), exfoliatin (eta, etb, etd) and virulence (pvl, Y-hlg) were also screened. Of all the genes examined, 67.74% of isolate were positive for the Y-hlg gene, followed by the sea gene in 25.8% whereas in none of the isolates the eta and the etb gene was amplified. The study also highlights the incidence of clinical isolates of CoNS, which are harboring the toxin and the virulence genes rendering them as a more potential threat. This is the first report of animal origin OS-MRS from India, which emphasizes on the inclusion of both the genetic and phenotypic test for proper characterization of CoNS and preventing resistant strain misidentification.

17.
Infect Genet Evol ; 48: 71-75, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27939332

RESUMO

Anaplasma marginale is a tick borne rickesttsial parasite known to cause bovine anaplasmosis. There are prevalence reports from different parts of India, however, information regarding genetic diversity and phylogenetic association of the Indian strains are unknown. In the current study, 965 cattle blood samples from two states of India, Seemandhra and Telangana, were investigated for the presence of A. marginale by PCR using major surface protein 4 gene (msp4). We found an overall infection of 16.4%, with 3.4% prevalence in Seemandhra and 22.2% in Telangana. Sequence analysis of the 24 cloned msp4 gene indicated genetic diversity among Indian clinical strains of A. marginale which may be due to evolutionary pressure or migration of strains. Phylogenetic association analysis revealed that most of the strains showed close proximity with strains from Mexico and other strains showed closeness to strains reported from countries like Brazil, Zimbabwe, Prico and Hungary. This is the first report from India, identifying heterogeneous population of A. marginale strains causing anaplasmosis, and such data can play an important role in designing new control policies.


Assuntos
Anaplasma marginale/genética , Anaplasmose/microbiologia , Doenças dos Bovinos/microbiologia , Anaplasmose/epidemiologia , Animais , Proteínas de Bactérias/genética , Bovinos , Doenças dos Bovinos/epidemiologia , Genes Bacterianos , Variação Genética , Genótipo , Índia/epidemiologia , Filogenia , Análise de Sequência de DNA
18.
PLoS One ; 11(9): e0162256, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27603123

RESUMO

Bovine mastitis caused by multidrug resistant Staphylococcus aureus is a huge problem reported worldwide, resulting in prolonged antibiotic treatment and death of livestock. The current study is focused on surveillance of antibiotic susceptibility along with genotypic and phenotypic characterization of the pathogenic S. aureus strains causing mastitis in India. One hundred and sixty seven milk samples were collected from mastitis-affected cows from different farms in India resulting in thirty nine isolated S. aureus strains. Antibiotic sensitivity profiling revealed the majority of the strains (n = 24) to be multidrug resistant and eleven strains showed reduced susceptibility to vancomycin (MICs = 2µg/ml). All strains were oxacillin sensitive, but 19 strains were positive for the mecA gene, which revealed the occurrence of oxacillin susceptible mecA positive strains (OS-MRSA) for the first time from India. Additionally, 32 strains were positive for the pvl gene, a virulence determinant; of these 17 were also OS-MRSA strains. Molecular characterization based on multilocus sequence typing (MLST), spa typing, agr typing and SCCmec classification revealed strains belonging to different groups. Moreover, strains showed spa types (t2526, t9602) and MLST sequence types, ST-72, ST-88 and ST-239 which have been earlier reported in human infections. The prevalence of OS-MRSA strains indicates the importance of including both the genetic and phenotypic tests in characterizing S. aureus strains. Increased genotypic variability with strain related to human infections and pvl positive isolates indicates a worrisome situation with the possibility of bilateral transfer.


Assuntos
Mastite Bovina/microbiologia , Oxacilina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Bovinos , Feminino , Amplificação de Genes , Genes Bacterianos , Genótipo , Mastite Bovina/patologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Proteínas de Ligação às Penicilinas/metabolismo , Fenótipo , Prevalência , Staphylococcus aureus/genética
19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 6046-6049, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28269631

RESUMO

In this paper we introduce Shape Memory Alloy (SMA) for designing the tibial part of Total Knee Arthroplasty (TKA) by exploiting the shape-memory and pseudo-elasticity property of the SMA (e.g. NiTi). This would eliminate the drawbacks of the state-of-the art PMMA based knee-spacer including fracture, sustainability, dislocation, tilting, translation and subluxation for tackling the Osteoarthritis especially for the aged people of 45-plus or the athletes. In this paper a Computer Aided Design (CAD) model using SolidWorks for the knee-spacer is presented based on the proposed SMA adopting the state-of-the art industry-standard geometry that is used in the PMMA based spacer design. Subsequently Ansys based Finite Element Analysis is carried out to measure and compare the performance between the proposed SMA based model with the state-of-the art PMMA ones. 81% more bending is noticed in the PMMA based spacer compared to the proposed SMA that would eventually cause fracture and tilting or translation of spacer. Permanent shape deformation of approximately 58.75% in PMMA based spacer is observed compared to recoverable 11% deformation in SMA when same load is applied on both separately.


Assuntos
Desenho Assistido por Computador , Articulação do Joelho/fisiologia , Prótese do Joelho , Níquel , Desenho de Prótese/métodos , Titânio , Análise de Elementos Finitos , Humanos , Níquel/química , Níquel/uso terapêutico , Titânio/química , Titânio/uso terapêutico
20.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 2456-2459, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28268821

RESUMO

In this paper we propose an on-the-fly reconfigurable hardware-software codesign based reconfigurable solution for real-time protein identification. Reconfigurable string matching is performed in the disciplines of protein identification and biomarkers discovery. With the generation of plethora of sequenced data and number of biomarkers for several diseases, it is becoming necessary to have an accelerated processing and on-the-fly reconfigurable system design methodology to bring flexibility to its usage in the medical science community without the need of changing the entire hardware every time with the advent of new biomarker or protein. The proteome database of human at UniProtKB (Proteome ID up000005640) comprising of 42132 canonical and isoform proteins with variable database-size are used for testing the proposed design and the performance of the proposed system has been found to compare favorably with the state-of-the-art approaches with the additional advantage of real-time reconfigurability.


Assuntos
Computadores , Proteínas/análise , Software , Bases de Dados de Proteínas , Humanos , Fatores de Tempo
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