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1.
Eur J Clin Microbiol Infect Dis ; 43(6): 1205-1212, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38557925

RESUMEN

Acute encephalitis syndrome (AES) outbreaks in children of Eastern Uttar Pradesh (E-UP) region of India have been a longstanding public health issue, with a significant case fatality rate of 20-25%. Since past decade, a rise in chikungunya (CHIK) cases has been occurring, which is a reported etiology of AES. However, the burden of chikungunya virus (CHIKV) among pediatric AES (pAES) is unknown from E-UP. We included 238 hospitalized pAES cases. The presence of IgM antibodies for CHIKV, and Dengue virus (DENV) was tested, and RT-PCR was performed for CHIKV and DENV in serologically confirmed CHIKV and DENV pAES cases. Positive samples were sequenced using Sangers sequencing. Further, to check for co-infection, IgM antibodies for other AES etiologies including Japanese encephalitis virus (JEV), Leptospira and Orientia tsutsugamushi (OT) in serum were also investigated. IgM ELISA demonstrated 5.04% (12) positivity for CHIKV. Among CHIKV IgM positive, 3 (25%, 3/12) pAES patients died. CHIKV genome was detected in 3 pAES specimens. Among which, 2 CHIKV cases were also positive for OT DNA. Partially sequenced CHIKV were genotyped as ECSA. The overall finding indicates evidence of CHIKV infection with high case fatality among pAES patients from E-UP. This study advocates constant serological and molecular surveillance of CHIKV in AES endemic regions of India.


Asunto(s)
Encefalopatía Aguda Febril , Anticuerpos Antivirales , Fiebre Chikungunya , Virus Chikungunya , Inmunoglobulina M , Humanos , India/epidemiología , Fiebre Chikungunya/mortalidad , Fiebre Chikungunya/epidemiología , Niño , Masculino , Femenino , Preescolar , Virus Chikungunya/genética , Virus Chikungunya/inmunología , Anticuerpos Antivirales/sangre , Inmunoglobulina M/sangre , Encefalopatía Aguda Febril/epidemiología , Lactante , Adolescente , Coinfección/mortalidad , Coinfección/virología , Coinfección/epidemiología , Virus del Dengue/genética , Virus del Dengue/inmunología , Filogenia , Brotes de Enfermedades
2.
Arch Microbiol ; 205(5): 178, 2023 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-37029825

RESUMEN

Scrub typhus (ST) caused by Orientia tsutsugamushi (OT), has long been known to cause acute encephalitis syndrome (AES) and acute febrile illness (AFI). The immunodominant 56 kDa protein of OT, which is encoded by the 56 kDa gene (1600 bp encoding 516-541 amino acids) is a commonly studied antigen for genotype and serotype assignment. Previous studies from India have utilized partial type specific antigen (TSA) 56 kDa sequences for OT strain characterisation. On the other hand, understanding the antigenic diversity of current OT strains, is critical for developing specific diagnostic tests and vaccines against ST. As a result, the current study analyses antigenic variants using the entire TSA56 ORF of OT from AES cases. Phylogenetic investigation using complete TSA56 ORF sequences revealed Karp and Gilliam were the circulating predominant strains of OT. Furthermore, Immuno-informatical analysis demonstrated that the majority of high-binding affinity CD4 TCEs against the most prevalent Indian human leukocyte antigen alleles were present in the S-VDIII/IV and S-VDIV spacer regions of TSA56 ORF. TSA56 conserved spacer is crucial for OT immunological response investigations. Further, the pathophysiological effects of spacer domains in ST require further investigation. Furthermore, the characterization of the TSA56 spacer region of the OT from different parts of India is critical for developing region-specific ST diagnostic assays and vaccines.


Asunto(s)
Encefalopatía Aguda Febril , Orientia tsutsugamushi , Tifus por Ácaros , Humanos , Orientia tsutsugamushi/genética , Filogenia , Encefalopatía Aguda Febril/genética , Tifus por Ácaros/diagnóstico , Tifus por Ácaros/epidemiología , India
3.
Int J Mol Sci ; 23(11)2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35682737

RESUMEN

The early management, diagnosis, and treatment of emerging and re-emerging infections and the rising burden of non-communicable diseases (NCDs) are necessary. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system has recently acquired popularity as a diagnostic tool due to its ability to target specific genes. It uses Cas enzymes and a guide RNA (gRNA) to cleave target DNA or RNA. The discovery of collateral cleavage in CRISPR-Cas effectors such as Cas12a and Cas13a was intensively repurposed for the development of instrument-free, sensitive, precise and rapid point-of-care diagnostics. CRISPR/Cas demonstrated proficiency in detecting non-nucleic acid targets including protein, analyte, and hormones other than nucleic acid. CRISPR/Cas effectors can provide multiple detections simultaneously. The present review highlights the technical challenges of integrating CRISPR/Cas technology into the onsite assessment of clinical and other specimens, along with current improvements in CRISPR bio-sensing for nucleic acid and non-nucleic acid targets. It also highlights the current applications of CRISPR/Cas technologies.


Asunto(s)
Sistemas CRISPR-Cas , Ácidos Nucleicos , Sistemas CRISPR-Cas/genética , ADN , Ácidos Nucleicos/genética , ARN , ARN Guía de Sistemas CRISPR-Cas
4.
Indian J Microbiol ; 60(3): 388-391, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32647398

RESUMEN

Pesticide accumulation in agricultural soils is an environmental concern, often addressed through distinct bioremediation strategies. This study has tried to analyze various soil bioremediation options viz., biostimulation, bioaugmentation, and natural attenuation in terms of efficiency and the response of autochthonous microbial flora by using atrazine as a model contaminant. Soil mesocosms were established with 100 kg of soil simulating the field conditions. The soil previously exposed to the herbicide was used for the bioaugmentation strategy undertaken in this study. We have tried to analyze how the microbial community responds to a foreign compound, both in terms of taxonomic and functional capacities? To answer this, we have analyzed metagenome of the mesocosms at a time point when 90% atrazine was degraded. Bioaugmentation for bioremediation proved to be efficient with a DT90 value of 15.48 ± 0.79 days, in comparison to the natural attenuation where the DT90 value was observed to be 41.20 ± 1.95 days. Metagenomic analysis revealed the abundance of orders Erysipelotrichales, Selemonadales, Clostridiales, and Thermoanaerobacterales exclusively in SBS mesocosm. Besides Pseudomonas, bacterial genera such as Achromobacter, Xanthomonas, Stenotrophomonas, and Cupriavidus have emerged as the dominant members in various bioremediation strategies tested in this study. Inclusive results suggest that inherent microbial flora adjust their community and metabolic machinery upon exposure to the pollutant. The site under pollutant stress showed efficient microbial communities to bio-remediate the newly polluted terrestrial ecologies in relatively less time and by economic means.

5.
Artículo en Inglés | MEDLINE | ID: mdl-29038276

RESUMEN

Vancomycin-resistant Enterococcus faecium strains (VREfm) are critical public health concerns because they are among the leading causes of hospital-acquired bloodstream infections. Chlorhexidine (CHX) is a bisbiguanide cationic antiseptic that is routinely used for patient bathing and other infection control practices. VREfm are likely frequently exposed to CHX; however, the long-term effects of CHX exposure have not been studied in enterococci. In this study, we serially exposed VREfm to increasing concentrations of CHX for a period of 21 days in two independent experimental evolution trials. Reduced CHX susceptibility emerged (4-fold shift in CHX MIC). Subpopulations with reduced daptomycin (DAP) susceptibility were detected, which were further analyzed by genome sequencing and lipidomic analysis. Across the trials, we identified adaptive changes in genes with predicted or experimentally confirmed roles in chlorhexidine susceptibility (efrE), global nutritional stress response (relA), nucleotide metabolism (cmk), phosphate acquisition (phoU), and glycolipid biosynthesis (bgsB), among others. Moreover, significant alterations in membrane phospholipids were identified for some populations with reduced DAP susceptibility. Our results are clinically significant because they identify a link between serial subinhibitory CHX exposure and reduced DAP susceptibility. In addition, the CHX-induced genetic and lipidomic changes described in this study offer new insights into the mechanisms underlying the emergence of antibiotic resistance in VREfm.


Asunto(s)
Antibacterianos/farmacología , Clorhexidina/farmacología , Daptomicina/farmacología , Enterococos Resistentes a la Vancomicina/efectos de los fármacos , Enterococos Resistentes a la Vancomicina/genética , Antiinfecciosos Locales/farmacología , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Ligasas/genética , Pruebas de Sensibilidad Microbiana , Mutación , Fosfolípidos/genética , Fosfolípidos/metabolismo
6.
Antimicrob Agents Chemother ; 60(4): 2209-21, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26810654

RESUMEN

Chlorhexidine is a bisbiguanide antiseptic used for infection control. Vancomycin-resistantE. faecium(VREfm) is among the leading causes of hospital-acquired infections. VREfm may be exposed to chlorhexidine at supra- and subinhibitory concentrations as a result of chlorhexidine bathing and chlorhexidine-impregnated central venous catheter use. We used RNA sequencing to investigate how VREfm responds to chlorhexidine gluconate exposure. Among the 35 genes upregulated ≥10-fold after 15 min of exposure to the MIC of chlorhexidine gluconate were those encoding VanA-type vancomycin resistance (vanHAX) and those associated with reduced daptomycin susceptibility (liaXYZ). We confirmed thatvanAupregulation was not strain or species specific by querying other VanA-type VRE. VanB-type genes were not induced. ThevanHpromoter was found to be responsive to subinhibitory chlorhexidine gluconate in VREfm, as was production of the VanX protein. UsingvanHreporter experiments withBacillus subtilisand deletion analysis in VREfm, we found that this phenomenon is VanR dependent. Deletion ofvanRdid not result in increased chlorhexidine susceptibility, demonstrating thatvanHAXinduction is not protective against chlorhexidine. As expected, VanA-type VRE is more susceptible to ceftriaxone in the presence of sub-MIC chlorhexidine. Unexpectedly, VREfm is also more susceptible to vancomycin in the presence of subinhibitory chlorhexidine, suggesting that chlorhexidine-induced gene expression changes lead to additional alterations in cell wall synthesis. We conclude that chlorhexidine induces expression of VanA-type vancomycin resistance genes and genes associated with daptomycin nonsusceptibility. Overall, our results indicate that the impacts of subinhibitory chlorhexidine exposure on hospital-associated pathogens should be further investigated in laboratory studies.


Asunto(s)
Antiinfecciosos Locales/farmacología , Proteínas Bacterianas/agonistas , Clorhexidina/análogos & derivados , Enterococcus faecium/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica , Resistencia a la Vancomicina/efectos de los fármacos , Antibacterianos/farmacología , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Ligasas de Carbono-Oxígeno/genética , Ligasas de Carbono-Oxígeno/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Clorhexidina/farmacología , Daptomicina/farmacología , Enterococcus faecium/genética , Enterococcus faecium/crecimiento & desarrollo , Enterococcus faecium/metabolismo , Perfilación de la Expresión Génica , Pruebas de Sensibilidad Microbiana , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Vancomicina/farmacología , Resistencia a la Vancomicina/genética
7.
Appl Microbiol Biotechnol ; 100(2): 903-13, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26403923

RESUMEN

The Arthrobacter sp. strain AK-YN10 is an s-triazine pesticide degrading bacterium isolated from a sugarcane field in Central India with history of repeated atrazine use. AK-YN10 was shown to degrade 99 % of atrazine in 30 h from media supplemented with 1000 mg L(-1) of the herbicide. Draft genome sequencing revealed similarity to pAO1, TC1, and TC2 catabolic plasmids of the Arthrobacter taxon. Plasmid profiling analyses revealed the presence of four catabolic plasmids. The trzN, atzB, and atzC atrazine-degrading genes were located on a plasmid of approximately 113 kb.The flagellar operon found in the AK-YN10 draft genome suggests motility, an interesting trait for a bioremediation agent, and was homologous to that of Arthrobacter chlorophenolicus. The multiple s-triazines degradation property of this isolate makes it a good candidate for bioremediation of soils contaminated by s-triazine pesticides.


Asunto(s)
Arthrobacter/genética , Arthrobacter/metabolismo , Atrazina/metabolismo , Biodegradación Ambiental , Herbicidas/metabolismo , Microbiología del Suelo , Arthrobacter/efectos de los fármacos , Arthrobacter/aislamiento & purificación , Atrazina/farmacología , Secuencia de Bases , Genoma Bacteriano , India , Plásmidos , Reacción en Cadena de la Polimerasa , Saccharum/microbiología
8.
Cureus ; 16(5): e61430, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38947601

RESUMEN

This case report describes the care given to a 58-year-old male patient with severe upper jaw atrophy. The treatment strategy involved utilizing zygomatic implants in conjunction with endosteal implants to rehabilitate both the maxilla and mandible. Temporary prostheses were used during the healing phase, followed by the fabrication and placement of final prostheses. The utilization of zygomatic implants offers advantages such as immediate stabilization and function without the need for extensive bone grafting. This approach not only reduces treatment time and costs but also enhances patient outcomes. Furthermore, guided surgical techniques are increasingly employed to ensure precise implant placement, optimizing prosthetic support.

9.
Mol Biotechnol ; 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38366109

RESUMEN

Calanthe mild mosaic virus (CalMMV) infecting orchids is an important potyvirus which is known to cause mild leaf mosaic and flower colour-breaking symptoms in Calanthe and other orchid plants. The present study reports the production of polyclonal antibodies against CalMMV using bacterially expressed recombinant coat protein as immunogen, which in turn would be useful in routine indexing and screening of orchid germplasm. The coat protein (CP) gene (~ 807 bp) of CalMMV isolated from infected orchid sample was cloned in expression vector, pET-28a ( +) that yielded ~ 31 kDa fusion protein with Histidine tag (His6BP). The expression of fusion CP was confirmed through SDS-PAGE and Western blotting. The His6BP-CalMMV-CP obtained in soluble state after purification was used to immunize New Zealand white rabbit for the production of polyclonal antibodies (PAb). The PAb produced against the purified fusion protein successfully detected CAlMMV in the orchid samples at a dilution of 1:2000 in direct antigen-coated enzyme-linked immunosorbent assay (DAC-ELISA). This study presents the first report of Histidine tag (His6BP) fusion CalMMV-CP-based antibody production and its successful application in the identification of the virus in orchid plants. Outcome of this study will be helpful in routine certification programmes, screening of orchid germplasm and production of CalMMV-free planting materials of orchids.

10.
Indian J Anaesth ; 68(2): 189-195, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38435662

RESUMEN

Background and Aims: Adequate sedation is essential for children undergoing magnetic resonance imaging (MRI) console. Propofol is commonly used for sedation, but it has the drawback of upper airway collapse at higher doses, which may be overcome by ketamine. This study was designed to evaluate the beneficial effect of ketamine on propofol in preventing airway collapse. Methods: Fifty-eight children undergoing MRI were randomised to Group P (propofol bolus dose followed by infusion or Group KP (bolus dose of ketamine and propofol followed by propofol infusion). The primary aim is to compare the upper airway cross-sectional area (CSA) and diameters (transverse diameter [TD] and anteroposterior diameter [APD]) obtained from MRI during inspiration and expiration. Results: Upper airway collapse as measured by delta CSA in mean (SD) [95% confidence interval] was statistically more significant between the two groups [at the soft palate level, 16.9 mm2 (19.8) [9.3-24.4] versus 9.0 mm2 (5.50) [6.9-11.1] (P = 0.043); at the base of the tongue level, 15.4 mm2 (11.03) [11.2-19.6] versus 7.48 mm2 (4.83) [5.64-9.32] (P < 0.001); at the epiglottis level, 23.9 (26.05) [14.0-33.8] versus 10.9 mm2 (9.47) [7.35-14.5] (P = 0.014)]. A significant difference was obtained for TD at all levels and for APD at the soft palate and base of tongue level. Conclusion: Adding a single dose of ketamine to propofol reduced the upper airway collapse significantly, as evidenced by the MRI-based measurements of upper airway dimensions, compared to propofol alone.

11.
Infect Dis Now ; 54(2): 104865, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38350558

RESUMEN

OBJECTIVES: To identify the potential target genes for detection of Orientia tsutsugamushi (OT) in pediatric acute encephalitis syndrome (pAES). METHODS: DNA was extracted from whole blood of 100 pAES cases having tested positive (n = 41) and negative (n = 59) for scrub typhus (ST) by IgM ELISA. These samples were subjected to standard PCR for 56 kDa, 47 kDa, 16 s rRNA, groEL, traD genes and the newly identified 27 kDa gene. RESULTS: Among the selected gene targets, 56 kDa demonstrated its superiority for OT detection over the other tested genes. The presence of OT was confirmed via PCR targeting 56 kDa gene in 17 out of the 41 (41.4 %) IgM-positive ST AES cases and 38 out of the 59 (64.4 %) ST IgM negative cases. None of the other gene targets were amplified. CONCLUSION: Integration of serological diagnosis with molecular diagnostics targeting the 56 kDa gene for routine testing of AES patients would facilitate detection of OT in AES endemic regions.


Asunto(s)
Encefalopatía Aguda Febril , Tifus por Ácaros , Niño , Humanos , Tifus por Ácaros/diagnóstico , Encefalopatía Aguda Febril/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina M , Reacción en Cadena de la Polimerasa
12.
ACS Nano ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39158149

RESUMEN

Ferroelectric all-inorganic halide perovskite nanocrystals with both spontaneous polarization and visible light absorption are promising candidates for designing ferroelectric photovoltaic applications. It remains a challenge to realize ferroelectric photovoltaic devices with all-inorganic halide perovskites that can be operated in the absence of an external electric field. Here we report that a popular all-inorganic halide perovskite nanocrystal, CsPbBr3, exhibits a ferroelectricity-driven photovoltaic effect under visible light in the absence of an external electric field. Pristine CsPbBr3 nanocrystals exhibit intrinsic ferroelectric key properties with a notable saturated polarization of ∼0.15 µC/cm2 and a high Curie temperature of 462 K, driven by the stereochemical activity of the Pb(II) lone pair. Furthermore, application of an external electric field allows the photovoltaic effect to be enhanced and the spontaneous polarization to be switched with the direction of the electric field. CsPbBr3 nanocrystals exhibit a robust fatigue performance and a prolonged photoresponse under continuous illumination in the absence of an external electric field. These findings establish all-inorganic halide perovskite nanocrystals as potential candidates for designing photoferroelectric devices by coupling optical functionalities and ferroelectric responses.

13.
EXCLI J ; 22: 451-465, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37534220

RESUMEN

SARS-CoV-2 has mutated rapidly since its first case report in Wuhan, China, leading to the emergence of an indefinite number of variants. India has witnessed three waves of the COVID-19 pandemic. The country saw its first wave of SARS-CoV-2 illness from late January 2020 to February 2021. With a peak surge of cases in mid-September 2020, India recorded more than 11 million cases and a death toll of more than 0.165 million at this time. India faced a brutal second wave driven by the emergence of highly infectious SARS-CoV-2 variants B.1.617.2 (Delta variant) and the third wave with the leading cause of BA.2 (Omicron variant), which has led to an unprecedented rise in COVID-19 cases in the country. On September 14, 2022, India recorded a cumulative 44.51 million cases of COVID-19 with more than 0.528 million deaths. The discovery of common circulating mutants is facilitated by genome sequencing. The changes in the Spike surface glycoprotein recombinant binding domains served as the critical alterations, resulting in enhanced infectivity and transmissibility, with severe clinical effects. Further, the predominant mutation in the SARS-CoV-2 spike protein; the D614G strains served as a model for vaccine development. The mutation of the Wuhan strain to the Variant of Concern led to a significant increase in SARS-CoV-2 infections. In addition, there was a shift in the age group affected by SARS-CoV-2 variant infection. The current review summarized the COVID-19 pandemic's Variant of Concern and the advent of SARS-CoV-2 in India.

14.
Virology ; 587: 109872, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37657354

RESUMEN

Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detection of groundnut bud necrosis virus (GBNV) causing potato stem necrosis disease. The isothermal temperatures, reaction periods and concentrations of reaction mixture were optimized where, the assay worked well at 65 °C for 50 min, 6 U of WarmStart Bst 2.0 DNA polymerase, 1.4 mM dNTPs and 2.0 mM MgSO4. The optimized assay proved to be specific to GBNV with no cross reactivity to other viruses infecting potato in India. The specificity of RT-LAMP assay was found to be 100 fold more sensitive than that of RT-PCR. The developed assay was applied for the detection of GBNV from 80 potato leaf samples where 24 samples were found infected which was confirmed by RT-PCR. It was concluded that the RT-LAMP assay developed for detection of GBNV was specific, sensitive and suitable for its use in virus indexing under potato seed production programme.


Asunto(s)
Solanum tuberosum , Virus , Transcripción Reversa , Técnicas de Amplificación de Ácido Nucleico , Sensibilidad y Especificidad
15.
PeerJ ; 11: e14504, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36643644

RESUMEN

Dengue fever is an endemic disease in India, transmitted by an infected mosquito bite. In India, the number of concurrent infections and the circulation of multiple dengue virus (DENV) serotypes has increased in recent decades. Molecular surveillance among the DENV serotype is important to keep track of the circulating serotypes, evolutionary changes, and key mutations that can alter the diagnostics. The current study included patients admitted for dengue in the Eastern Uttar Pradesh (E-UP) region during 2018-2019. The genetic characterization of the circulating DENV was accomplished through partial CprM (511 bp) gene amplification via reverse transcriptase polymerase chain reaction and sequencing. Phylogenetic analysis revealed the circulation of all four DENV1-4 serotypes. DENV-2 was the most abundant serotype (44%, 27/61), followed by DENV-3 (32%, 20/61). DENV-1 had a 16% (10/61) predominance, while DENV-4 (6%, 4/61) was found to be the least abundant serotype. DENV-2 genotypes were distributed among lineages I (7.4%), II (85%) and III (7.4%) of genotype IV, DENV-3 to lineage III of genotype III, DENV-1 to genotype III; DENV-2 to lineage B (75%) and C (25%) of genotype I. This primary report on the co-circulation of DENV1-4 serotypes from the E-UP region highlights the requirement of continuous molecular surveillance for monitoring circulating DENV serotypes.


Asunto(s)
Virus del Dengue , Dengue , Humanos , Virus del Dengue/genética , Dengue/epidemiología , Serogrupo , Filogenia , India/epidemiología
16.
Biosensors (Basel) ; 13(12)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38131781

RESUMEN

Orientia tsutsugamushi is responsible for causing scrub typhus (ST) and is the leading cause of acute encephalitis syndrome (AES) in AES patients. A rapid and sensitive method to detect scrub typhus on-site is essential for the timely deployment of control measures. In the current study, we developed a rapid, sensitive, and instrument-free lateral flow assay (LFA) detection method based on CRISPR/Cas12a technology for diagnosing ST (named LoCIST). The method is completed in three steps: first, harnessing the ability of recombinase polymerase for isothermal amplification of the target gene; second, CRISPR/Cas12a-based recognition of the target; and third, end-point detection by LFA. The detection limit of LoCIST was found to be one gene copy of ST genomic DNA per reaction, and the process was complete within an hour. In 81 clinical samples, the assay showed no cross-reactivity with other rickettsial DNA and was 100% consistent with PCR detection of ST. LoCIST demonstrated 97.6% sensitivity and 100% specificity. Overall, the LoCIST offers a novel alternative for the portable, simple, sensitive, and specific detection of ST, and it may help prevent and control AES outbreaks due to ST. In conclusion, LoCIST does not require specialized equipment and poses a potential for future applications as a point-of-care diagnostic.


Asunto(s)
Orientia tsutsugamushi , Tifus por Ácaros , Humanos , Tifus por Ácaros/diagnóstico , Tifus por Ácaros/genética , Sistemas CRISPR-Cas , Sensibilidad y Especificidad , Orientia tsutsugamushi/genética , ADN
17.
Zoonoses Public Health ; 70(5): 403-410, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37086017

RESUMEN

The Eastern Uttar Pradesh region of India is known for its endemicity of acute encephalitis syndrome (AES). Decades of research have established that Orientia tsutsugamushi, a causative of scrub typhus, is a substantial contributor (>60%) for the AES cases besides other aetiology, but additional factors in the remaining proportion are still unidentified. Rickettsial infections are challenging to diagnose in clinical settings due to overlapping clinical symptoms, the absence of definitive indicators, a low index of suspicion, and the lack of low-cost, rapid diagnostic tools. Hence, the present study was designed to determine the load of rickettsial infections among AES cases. Furthermore, we aim to find out the prevalent rickettsial species in AES cases as well as in the vector population at this location. The study included the whole blood/cerebrospinal fluid of AES patients and arthropod specimens from rodents. The molecular identification was performed using the 23S-5S intergenic spacer region and ompB gene with genomic DNA obtained from studied specimens. We detected 5.34% (62/1160) of rickettsial infection in AES cases. Among these, phylogenetic analysis confirmed the presence of 54.8% Rickettsia conorii (n = 34) and 16.1% of Rickettsia felis (n = 10), while the rest proportion of the isolates was unidentified at the species level. Furthermore, R. felis was identified in one CSF sample from AES patients and three flea samples from Xenopsylla cheopis. Rickettsia spp. was also confirmed in one Ornithonyssus bacoti mite sample. The results of this investigation concluded the presence of spotted fever group Rickettsia spp. among AES identified cases as well as in the mite and flea vectors that infest rodents.


Asunto(s)
Encefalopatía Aguda Febril , Infecciones por Rickettsia , Rickettsia , Tifus por Ácaros , Rickettsiosis Exantemáticas , Animales , Encefalopatía Aguda Febril/epidemiología , Encefalopatía Aguda Febril/etiología , Encefalopatía Aguda Febril/veterinaria , Filogenia , Tifus por Ácaros/epidemiología , Tifus por Ácaros/veterinaria , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/veterinaria , Roedores , Rickettsiosis Exantemáticas/epidemiología , Rickettsiosis Exantemáticas/veterinaria , India/epidemiología
18.
PLoS One ; 16(4): e0249631, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33831063

RESUMEN

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that cause life-threatening infections. To control hospital-associated infections, skin antisepsis and bathing utilizing chlorhexidine is recommended for VRE patients in acute care hospitals. Previously, we reported that exposure to inhibitory chlorhexidine levels induced the expression of vancomycin resistance genes in VanA-type Enterococcus faecium. However, vancomycin susceptibility actually increased for VanA-type E. faecium in the presence of chlorhexidine. Hence, a synergistic effect of the two antimicrobials was observed. In this study, we used multiple approaches to investigate the mechanism of synergism between chlorhexidine and vancomycin in the VanA-type VRE strain E. faecium 1,231,410. We generated clean deletions of 7 of 11 pbp, transpeptidase, and carboxypeptidase genes in this strain (ponA, pbpF, pbpZ, pbpA, ddcP, ldtfm, and vanY). Deletion of ddcP, encoding a membrane-bound carboxypeptidase, altered the synergism phenotype. Furthermore, using in vitro evolution, we isolated a spontaneous synergy escaper mutant and utilized whole genome sequencing to determine that a mutation in pstB, encoding an ATPase of phosphate-specific transporters, also altered synergism. Finally, addition of excess D-lactate, but not D-alanine, enhanced synergism to reduce vancomycin MIC levels. Overall, our work identified factors that alter chlorhexidine and vancomycin synergism in a model VanA-type VRE strain.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Adenosina Trifosfatasas/metabolismo , Proteínas Bacterianas/metabolismo , Clorhexidina/farmacología , Sinergismo Farmacológico , Enterococcus faecium/efectos de los fármacos , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Ácido Láctico/metabolismo , Vancomicina/farmacología , Transportadoras de Casetes de Unión a ATP/genética , Adenosina Trifosfatasas/genética , Antibacterianos/farmacología , Antiinfecciosos Locales/farmacología , Proteínas Bacterianas/genética , Infecciones por Bacterias Grampositivas/genética , Infecciones por Bacterias Grampositivas/microbiología , Humanos
19.
Access Microbiol ; 3(3): 000214, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34151166

RESUMEN

Enterococcus faecalis and E. faecium are Gram-positive bacteria that normally inhabit the human gastrointestinal tract. They are also opportunistic pathogens and can cause nosocomial infection outbreaks. To prevent the spread of nosocomial infections, hospitals may rely on screening methods to identify patients colonized with multidrug-resistant organisms including vancomycin-resistant enterococci (VRE). Spectra VRE agar (Remel) contains vancomycin and other medium components that select for VRE and phenotypically differentiate between E. faecalis and E. faecium by colony colour. We obtained 66 de-identified rectal swab cultures on Spectra VRE agar that were obtained during routine patient admission surveillance at a hospital system in Dallas, Texas, USA. We analysed 90 presumptive VRE from 61 of the Spectra VRE agar cultures using molecular and culture methods. Using ddl typing, 55 were found to be E. faecium and 32 were found to be E. faecalis . While most of the E. faecium were positive for the vanA gene by PCR (52 of 55 strains), few of the E. faecalis were positive for either vanA or vanB (five of 32 strains). The 27 E. faecalis vanA- and vanB-negative strains could not be recultured on Spectra VRE agar. Overall, we found that Spectra VRE agar performed robustly for the identification of vancomycin-resistant E. faecium , but presumptive false positives were obtained for vancomycin-resistant E. faecalis .

20.
Curr Drug Deliv ; 18(4): 500-512, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32723271

RESUMEN

OBJECTIVE: The objective of the current research work was to prepare chewable tablets having Acacia catechu extract useful for mouth ulcers using a 32 factorial design. METHODS: Acacia catechu heartwood extract was prepared using a reported method with some modifications. The extract was characterized using TLC against the catechin marker. Then, drug-excipient interaction studies were carried out. The mixture of drug and excipients was evaluated for pre-compression parameters. With the application of 32 factorial design, chewable tablets were prepared using direct compression technique. Prepared tablets were evaluated for post-compression parameters. RESULTS: In vitro drug release study of the developed formulations was investigated both in intact and crushed form of tablets. Based on the in vitro performance, the best formulations were selected (F6, F7 & F8 from intact and F1, F5 & F9 from the crushed group) and subjected to various kinetic models and evaluated for Chewing Difficulty Index (CDI). CONCLUSION: The overall results revealed that the formulated chewable tablets complied with the standards and exhibited the satisfactory performance in terms of drug release, chewing difficulty index and other related parameters.


Asunto(s)
Acacia , Úlceras Bucales , Extractos Vegetales/administración & dosificación , Comprimidos , Acacia/química , Administración Oral , Excipientes , Úlceras Bucales/tratamiento farmacológico
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