Antibacterial substances produced by pathogen inhibitory gut bacteria in Labeo rohita: Physico-chemical characterization, purification and identification through MALDI-TOF mass spectrometry.

Application of antibiotics to combat bacterial diseases in fish has been criticized due to likely emergence of drug resistance. Therefore, investigation of new bioactive compounds from natural sources has been taken into account. This study was designed to purify and characterize the bioactive compound in the cell free supernatant (CFSs) of autochthonous gut bacteria (Bacillus methylotrophicus KU556164, B. amyloliquefaciens KU556165, Pseudomonas fluorescens KU556166 and B. licheniformis KU556167) isolated from rohu, Labeo rohita. CFSs were antagonistic to fish pathogenic Aeromonas spp., moderately thermo-tolerant and active in wide range of pH (5-11). Antibacterial activity of the CFSs was reduced by the action of proteases (e.g., Proteinase K and Trypsin), indicating proteinaceous nature of the bioactive compound like the bacteriocins. Three-step purification procedure resulted in recovery of 16.97%, 18.04%, 33.33% and 6.38% activity of the antimicrobial protein produced by B. methylotrophicus, B. amyloliquefaciens, P. fluorescens and B. licheniformis, respectively. Purification at each step revealed decrease in protein content with gradual increase in the specific activity of the antimicrobial protein. The purified antibacterial compound ranged between 18.2 and 25.6 kDa. Identification through MALDI-TOF MS/MS and database search through Mascot search engine predicted that the bactericidal compound belonged to either alkaline proteases, or, transcriptional regulator and some hypothetical proteins. Apart from potential technological application of the antibacterial compound, the present study might show promise for application of gut-associated bacteriocinogenic bacteria to control diseases in fish caused by pathogenic bacteria.

A scattered volume emitter micropixel architecture for ultra efficient light extraction from DUV LEDs.

Deep ultraviolet light-emitting diodes (DUV LEDs) typically suffer from strong parasitic absorption in the p-epitaxial layer and rear metal contact/mirror. This problem is exacerbated by a substantial portion of the multiple quantum well (MQW) emissions having a strong out-of-plane dipole component, contributing to emission in widely oblique directions outside the exit cone of the front semiconductor emitting surface. To address this, we propose an architecture that leverages such a heavily oblique angular emission profile by utilizing spaced-apart or scattered volume emitter micropixels that are embedded in a low-index dielectric buffer film with a patterned top surface. This approach achieves high light extraction efficiency at the expense of enlarging the effective emission area, however, it does not require a high-index (e.g., sapphire) substrate or a lens or a nanotextured epi for outcoupling purposes. Hybrid wave and ray optical simulations demonstrated a remarkable larger than three to sixfold increase in light extraction efficiency as compared to that of a conventional planar LED design with a sapphire substrate depending on the assumed epi layer absorption, pixel size, and ratio of light emission area to the MQW active area. An extraction efficiency three times greater than that of a recent nanotextured DUV LED design was also demonstrated. This architecture paves the way for DUV LEDs to have a plug efficiency comparable to that of mercury lamps while being significantly smaller.

Genital Chlamydia trachomatis: an update.

Chlamydia trachomatis is the most common cause of curable bacterial sexually transmitted infection (STI) worldwide. It manifests primarily as urethritis in males and endocervicitis in females. Untreated chlamydial infection in man can cause epididymitis and proctitis. Though most women with Chlamydia infection are asymptomatic or have minimal symptoms, some develop salpingitis, endometritis, pelvic inflammatory disease (PID), ectopic pregnancy and tubal factor infertility. It is associated with an increased risk for the transmission or acquisition of HIV and is also attributed to be a risk factor for the development of cervical carcinoma. Early diagnosis and treatment of infected individuals is required to prevent the spread of the disease and severe sequelae. Traditionally, tissue culture was considered the gold standard for the diagnosis. However, with the availability of newer diagnostic techniques particularly molecular methods which are not only highly sensitive and specific but are cost-effective also, the diagnosis has became fast and easy. The purpose of this review is to study the various aspects of genital C. trachomatis infection. Also the advances related to the clinical picture, various diagnostic modalities, prevention, treatment, drug resistance and control measures will be dealt with.

Isolation & characterization of Bartonella sp. from optic neuritis patients.

BACKGROUND & OBJECTIVES: Optic neuritis (ON) is characterized by sudden and rapid impairment of vision. Bartonella henselae is a known aetiological agent of cat scratch disease (CSD), which is a common cause of neuroretinitis, the least common type of optic neuritis. The present study was carried out to determine the microbiological aetiology of optic neuritis in patients attending a tertiary care eye hospital in north India, which was later confirmed with molecular characterization. METHODS: Of the 50 patients suffering from optic neuritis reported to the Ophthalmology OPD of a tertiary care eye hospital in New Delhi, India, 29 were included in the study. Blood culture from these patients were processed for aerobic and anerobic cultures to rule out infective aetiology. Subsequently, PCR was done on archive, glycerol-stocked cultures. RESULTS: Gram-negative pleomorphic coccobacilli grew in four of 29 patients tested. Characterization of these revealed Bartonella like organism as tested by the API 20E, API Staph, API Strept and RapID ANA systems. Electron microscopy revealed presence of polar flagella and bleb like projection all over the bacterial surface. PCR performed on preserved culture confirmed these as Bartonella sp. INTERPRETATION & CONCLUSIONS: Infections with Bartonella like organisms have not been demonstrated from India in cases of optic neuritis or in any of the other clinical syndromes in the past. The present study shows the isolation and characterization of Bartonella like organisms from optic neuritis patients. From clinical point of view it will be important to look for these organisms as aetiological agents in ON cases in order to treat with appropriate antibiotics.

Interval-Valued Intuitionistic Fuzzy Soft Rough Approximation Operators and Their Applications in Decision Making Problem.

It has been found that fuzzy sets, rough sets and soft sets are closely related concepts. Many complicated problems in economics, engineering, social sciences, medical science and many other fields involve uncertain data. These problems, which one comes in real life, cannot be solved using classical mathematical methods. There are several well-known theories to describe uncertainty, for instance, fuzzy set theory, rough set theory, and other mathematical tools. But all of these theories have their inherit difficulties as pointed out by D. Molodtsov. In 1999, D. Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainties. The concept of rough sets, proposed by Z. Pawlak as a framework for the construction of approximations of concepts. It is a formal tool for modeling and processing insufficient and incomplete information. Zhou and Wu first proposed the concept of intuitionistic fuzzy rough sets (IFrough sets). The aim of this paper is to introduce the concept of interval-valued intuitionistic fuzzy soft rough sets (IVIFS rough sets). We also investigate some properties of IVIFS rough approximation operators. Some basic operations and properties are studied. Lastly applications have been shown in decision making problems.

Application of Neutrosophic Similarity Measures in Covid-19.

The contemporary situation of the world is very pathetic due to the spread of COVID-19. In this article, we have prepared a decision making model on COVID-19 pandemic patients with the help of the neutrosophic similarity measures. The model is to predict the COVID-19 patents for testing positive and testing negative. The decision making is based on the testing result of the COVID-19 cases. We have used the neutrosophic similarity measure theory and the distance function. We have used the C-programming for finding the result of the suspected patients.

Single GaAs Nanowire/Graphene Hybrid Devices Fabricated by a Position-Controlled Microtransfer and an Imprinting Technique for an Embedded Structure.

We developed a new technique to fabricate single nanowire devices with reliable graphene/nanowire contacts using a position-controlled microtransfer and an embedded nanowire structure in a planar junction configuration. A thorough study of electrical properties and fabrication challenges of single p-GaAs nanowire/graphene devices was carried out in two different device configurations: (1) a graphene bottom-contact device where the nanowire-graphene contact junction is formed by transferring a nanowire on top of graphene and (2) a graphene top-contact device where the nanowire-graphene contact junction is formed by transferring graphene on top of an embedded nanowire. For the graphene top-contact devices, graphene-nanowire-metal devices, where graphene is used as one electrode and metal is the other electrode to a nanowire, and graphene-nanowire-graphene devices, where both electrodes to a nanowire are graphene, were investigated and compared with conventional metal/p-GaAs nanowire devices. Conventional metal/p-GaAs nanowire contact devices were further investigated in embedded and nonembedded nanowire device configurations. A significantly improved current in the embedded device configuration is explained with a "parallel resistors model" where the high-resistance parts with the metal-semiconductor Schottky contact and the low-resistance parts with noncontacted facets of the hexagonal nanowires are taken into consideration. Consistently, the nonembedded nanowire structure is found to be depleted much easier than the embedded nanowires from which an estimation for a fully depleted condition has also been established.

Potential probiotics from Indian major carp, Cirrhinus mrigala. Characterization, pathogen inhibitory activity, partial characterization of bacteriocin and production of exoenzymes.

The study explored antagonistic activity of the cellular components of potential probiotic bacteria from mrigal (Cirrhinus mrigala) against fish pathogens with a basic insight of the chemical nature of the antagonistic compound. Totally 208 autochthonous gut bacteria were isolated, of which 22 strains revealed antagonism towards ≥2 of the six common fish pathogens. Zones of inhibition (halo diameter) were presented as score and the four most promising strains were selected as putative probiotics based on the cumulative score assigned. Further, evaluation of different cellular components exhibited bactericidal activity against the fish pathogens. Verification of other probiotic properties revealed that each of the selected strains produced diverse extra-cellular enzymes. The selected strains grew better in intestinal mucus than skin mucus, were resistant to diluted bile juice (2-20%) and safe for the target fish. The extracellular product used as crude bacteriocin revealed thermostability (up to 90°C) and activity over wide pH range (4-9). Partial loss of activity through treatment with proteinase-K and trypsin indicated proteinaceous nature of the antibacterial compound produced by the probiotic strains. 16S rRNA partial gene sequencing revealed that the four strains CM1FG7, CM1HG5, CM3FG19 and CM3HG10 were similar to Bacillus stratosphericus (KM277362), Bacillus aerophilus (KM277363), Bacillus licheniformis (KM277364) and Solibacillus silvestris (KM277365), respectively.

Postcataract surgery endophthalmitis caused by acinetobacter lwoffii.

Acinetobacter lwoffii is a rare cause of endophthalmitis. We report a case of acute postoperative endophthalmitis in a female, who was treated successfully with pars plana vitrectomy and intravitreal antibiotics.

Aspergillus terreus endogenous endophthalmitis: report of a case and review of literature.

We report a rare case of Aspergillus terreus endogenous endophthalmitis in an immunocompetent patient with subretinal abscess and also review the reported cases. A 50-year-old healthy male presented with sudden painful loss of vision in right eye. He was diagnosed with endogenous endophthalmitis and underwent urgent vitrectomy. Aspergillus terreus growth was obtained in culture. At final follow-up, there was complete resolution of the infection but visual acuity was poor due to macular scar. Aspergillus terreus is a rare cause of endophthalmitis with usually poor outcomes. Newer antifungals like Voriconazole can be sometimes associated with better prognosis.

Cytomegalovirus reactivation following hematopoietic stem cell transplantation.

INTRODUCTION: There is a high prevalence of cytomegalovirus (CMV) seropositivity in developing countries. An apparent risk of CMV reactivation increases following hematopoeitic stem cell transplantation. With effective surveillance and timely treatment using anti-viral therapy, morbidity and mortality associated with CMV reactivation can be reduced. OBJECTIVES: To evaluate the incidence and morbidity associated with CMV reactivation following hematopoeitic stem cell transplantation. METHODOLOGY: We retrospectively analysed 136 hematopoeitic stem cell transplant recipients at our centre for CMV reactivation and their complications. Quantification of CMV-DNA was done by PCR. CMV disease was confirmed histologically via CMV inclusion bodies or immunostaining of biopsy of the affected organ, mainly the gastrointestinal tract. RESULTS: A total of 13 out of 136 patients (9.56%) had CMV reactivation. 6 out of 13 patients had CMV disease, 3 of which died (23.1% of patients with CMV reactivation). CMV reactivation occurred at a median duration of 52.5 days post transplantation (range 35-178 days). The gastrointestinal tract was the organ most commonly affected by CMV. The median follow-up was 14 months (range 6 - 64 months). CONCLUSION: Through a higher rate of sero-prevalance in developing countries, the incidence of CMV infection following hematopoeitic stem cell transplantation is comparable to that reported in Western literature. Oral valganciclovir was an effective pre-emptive therapy for CMV disease.

A pilot study for diagnosis of genital Chlamydia trachomatis infections by polymerase chain reaction among symptomatic Indian women.

BACKGROUND: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. AIM: A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. METHODS: 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. RESULTS: Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. CONCLUSIONS: In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.

Coexisting pulmonary tuberculosis and mucormycosis in a patient with aplastic anemia post allogenic stem cell transplantation.

Infections are the most common cause of morbidity and mortality in allogenic stem cell transplant recipients. Survival of the patient depends on the accurate diagnosis of the infectious agents and prompt and effective management of the infection alongwith maintenance of adequate immunosuppression post transplantation. We here reported a case of aplastic anemia who developed left upper lobe consolidation post allogenic stem cell transplantation and was found to have combined infection with tuberculosis and mucormycosis. This is the first case of combined infection with tuberculosis and mucormycosis reported in such a host, with a favourable outcome.