Different Efflux Pump Systems in Acinetobacter baumannii and Their Role in Multidrug Resistance.

Several infections, such as pneumonia, urinary tract infections (UTIs), as well as bloodstream, skin, and soft tissue infections, are caused by Acinetobacter baumannii, a nosocomial pathogen and Gram-negative coccobacillus. Due to its resistance to a variety of medications, multidrug therapy, and occasionally pan therapies, this bacterium is a huge public health concern. Drug resistance is a big worry not only in A. baumannii, but it is also a major challenge in many other diseases. Antibiotic resistance, biofilm development, and genetic alterations are all linked to variables like the efflux pump. Efflux pumps are transport proteins involved in the extrusion of hazardous substrates from within cells into the external environment (including nearly all types of therapeutically relevant antibiotics). Both Gram-positive and Gram-negative bacteria, as well as eukaryotic organisms, contain these proteins. Efflux pumps may be specialized for a single substrate or can transport a variety of structurally dissimilar molecules (including antibiotics of many classes); these pumps have been linked to multiple drug resistance (MDR). There are five primary families of efflux transporters in the prokaryotic kingdom: MF (major facilitator), MATE (multidrug and toxic efflux), RND (resistance-nodulation-division), SMR (small multidrug resistance), and ABC (ATP-binding cassette). The efflux pumps and their types as well as the mechanisms of an efflux pump involved in multidrug resistance in bacteria have been discussed here. The main focus is on the variety of efflux pumps commonly found in A. baumannii, along with their mechanism by which they make this bacteria drug resistant. The efflux-pump-inhibitor-based strategies that are significant in targeting efflux pumps in A. baumannii have also been discussed. The connection of biofilm and bacteriophage with the efflux pump can prove as an efficient strategy for targeting efflux-pump-based resistance in A. baumannii.

Antipersister strategies against stress induced bacterial persistence.

The increase in antibiotic non-responsive bacteria is the leading concern in current research oriented to eliminate pathogens. Nowadays, the excess use of antibiotics without specifically understanding the potentiality of killing pathogens and bacterial survival patterns has helped bacteria emerge indefatigably. Bacteria use various mechanisms such as resistance, persistence, and tolerance to ensure survival. Among these, persistence is a mechanism by which bacteria reside in their dormant state, bypassing the effects of treatments, making it crucial for bacterial survival. Persistent bacterial cells arise from the normal bacterial population as a slow-growing subset of bacteria with no metabolic flux. This behavior renders it to survive for a longer duration and at higher concentrations of antibiotics. They are one of the underlying causes of recurrence of bacterial infections. The present article explains the detailed molecular mechanisms and strategies of bacterial persistence, including the toxin-antitoxin modules, DNA damage, the formation of inactive ribosomal complexes, (p)ppGpp network, antibiotic-induced persistence, which are triggered by drug-induced stress. The article also comprehensively covers the epigenetic memory of persistence in bacteria, and anti-persistent therapeutics like antimicrobial molecules, synthetic peptides, acyldepsipeptide antibiotics, and endolysin therapy to reduce persister cell formation and control their frequency. These strategies could be utilized in combating the pathogenic bacteria undergoing persistence.

Co-infection with Campylobacter and rotavirus in less than 5 year old children with acute gastroenteritis in Nepal during 2017-2018.

BACKGROUND: Diarrhoea, although easily curable, is a global cause of death for a half million children every year. Rotavirus and Campylobacter are the most common etiological agents of diarrhoea in children less than 5 years of age. However, in Nepal, these causative agents are not routinely examined for the diagnosis and treatment. The main objective of this study was to determine Campylobacter co-infection associated with rotavirus diarrhoea in children less than 5 years of age. METHODS: A cross-sectional study was conducted at Kanti Children's Hospital (KCH), Kathmandu, Nepal from November 2017 to April 2018. A total of 303 stool specimens from children affected with diarrhoea were processed to detect rotavirus using a rapid rotavirus antigen detection test kit, and Campylobacter by microscopy, culture and biochemical tests. Antibiotic susceptibility tests of Campylobacter isolates were performed according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines 2015. RESULTS: Of 303 samples, 91 (30.0%) were positive for co-infection with rotavirus and Campylobacter. Rotavirus mono-infection was detected in 61 (20.1%), and Campylobacter mono-infection was detected in 81 (26.7%) samples. Patient's age, month of infection, untreated water and frequent soil contact were the major risk factors for infections. Clinical features such as > 9 loose motions per day, fever, vomiting, mild to moderate dehydration, diarrhea persisting 6-9 days and presence of mucus in stool were significant (p < 0.05) clinical features, and were more severe in coinfection compared to mono-infections in multivariate analysis. CONCLUSION: The study shows a high rate of rotavirus and Campylobacter coinfection in children with diarrhoea. Diagnosis based management of diarrhoeal cases can guide the specific treatment.

Characterisation of the impact of dissolved organic matter on iron, manganese, and arsenic mobilisation during bank filtration.

Bank filtration (BF) has been used for many years as an economical technique for providing high-quality drinking water. However, under anaerobic conditions, the aquifer release of undesirable metal(loid)s, such as iron manganese, and arsenic, reduces the bank filtrate quality and thus restricts the application of this technique. This study investigates the impact of the organic-matter composition of source water on the mobilisation of Fe, Mn, and As during the anaerobic BF process. A laboratory-scale column study was conducted at a controlled-temperature (30 ± 2 °C) using different feed water sources. The organic matter characteristics of the feed water were elucidated using excitation-emission spectroscopy techniques integrated with parallel factor framework clustering analysis (PFFCA) model. The experiment was performed at redox conditions between 66 mv and -185 mv. Moreover, batch studies were implemented to study the effect of natural organic matter type (humic, fulvic and tyrosine) and concentration on the mobilisation of the selected metal(loids). The laboratory experiments demonstrated that the mobilisation of Fe, Mn and As during the BF are varied with the organic water concentration and composition of the source water. The fluorescence results revealed that terrestrial and condensed structure humic compounds are more capable to release Fe into the filtrate water. In contrast, Mn exhibited an equal tendency of mobilisation towards all the humic compounds regardless of its origin and structure. However, at a humic concentration higher than 5 mg-C/L, Mn showed more affinity towards lower molecular weight humic compounds. Arsenic was found to be the least impacted by the alteration in the source water organic matter composition; its mobilisation was highly correlated with iron releasing process. On the other hand, the biodegradable organic matter at high concentration (>10 mg-C/L) was found to be highly effective to turn the infiltration area into Fe-reducing environment and thereby elevating Fe and As concentrations in the pumped water. In conclusion, this study revealed that the DOM composition and concentration of the raw water could play an important role in the mobilisation of metal(loids) during the BF processes.

Sewage-fed aquaculture: a sustainable approach for wastewater treatment and reuse.

This study assesses the long-term sustainability for operation and maintenance (O&M) of sewage-fed aquaculture-based sewage treatment system. The study focused on the integrated assessment of an engineered pond system of 8 million liters per day capacity in the city of Karnal, the State of Haryana, northern India. Major areas during the assessment included health, environmental, societal and institutional views aspects as well as the quality of treated effluent subjected for reuse. The treatment facility met the Indian regulatory standards (downstream reuse and discharge into the legally permitted water bodies) in terms of physical-chemical parameters. The total coliform and faecal coliform removal were up to 2-3 log units; nevertheless, it was not capable to come across the bacterial count requirement (<1,000 per 100 mL to minimise human health risk in aquaculture practices). The system was able to generate sufficient net income required for routine O&M. Annual revenue collected by the Municipal Corporation from the lease of the facility as well as selling of treated wastewater was $3,077 and $16,667-$25,000, respectively. The additional benefit from the facility for the farmers included the saving of fertilizers and cheapest source of water available for irrigation. Recycling of treated sewages for irrigation is also returned nutrients to the surrounding farms in Karnal. This exercise has saved significant quantities of chemical fertilizer (26-41 Ton of nitrogen, 10-18 Ton of phosphorous and 38-58 Ton of potassium per year) and the overall benefit for farmers during cultivation of one acre of crop was calculated to be approximately $133 per year.

Polyvinylpyrrolidone capped silver nanoparticles enhance the autophagic clearance of Acinetobacter baumannii from human pulmonary cells.

Acinetobacter baumannii, an opportunistic pathogen has shown an upsurge in its multi-drug resistant isolates. OmpA of A. baumannii induces incomplete autophagy and apoptosis in host cells. Various therapeutic alternatives are under investigation against A. baumannii. Here, the major emphasis has been laid on comparing the efficacy of AgNP with different capping agents. OmpA targeted lead, Ivermectin capped AgNP (IVM-AgNP) has been compared with the antibacterial polyvinylpyrrolidone capped AgNP (PVP-AgNP) for their role in the modulations of host autophagy. Upregulation of p62 and LC3B confirmed by real-time PCR analysis indicated an increased autophagic flux upon the treatment with AgNPs. The elongation and closure of autophagic vacuoles was also supported by upregulated Atg genes (Atg4, Atg3, Atg5) in A. baumannii infected cells after treatment with AgNP. Autophagic flux increased on treatment with PVP-AgNP as suggested by the rise in mcherryLC3B fluorescence in A549 cells treated with PVP-AgNP as compared to the GFP-LC3B of IVM-AgNP. This suggests that PVP-AgNP treatment more effectively promotes the elongation and maturation stages of autophagy by increasing autophagic flux. These results indicate that capped AgNPs have the efficiency to revert the incomplete autophagy induced by A. baumannii back to normal autophagic levels.

Design and Fabrication of Broad-Spectrum Antimicrobial Porous Metallo-Polymeric Microsphere for Water Disinfection.

An expedient and efficient approach is used to synthesize a new class of metallo-polymeric microspheres (MPMs) as antimicrobials to succumb the wide range of bacteria from water. Three types of MPMs, that is, poly[Silver (I)-methacrylate-co-methylmethacrylate] (pAgMA), poly[Copper (II)-methacrylate-co-methyl methacrylate] (pCuMA), and poly[Nickel (II)-methacrylate-co-methylmethacrylate] (pNiMA), are prepared via radical suspension polymerization technique in 3D shape with porous texture. The structural and morphological characterization of the prepared microspheres are examined by analytical techniques. The antimicrobial potentialities of prepared MPMs are investigated at the laboratory scale study, revealing that the MPMs exhibit strong antibacterial activity (≈99.9% killing) against Gram-negative and Gram-positive bacteria [Enterobacter hormaechei (EH), Bacillus megatarium (BM), and Bacillus bataviensis (BB)]. The MacConkey agar medium test reveals that MPMs have substantial biocidal efficacy against broad-spectrum Gram-negative bacteria present in tap water. The MPMs exhibit significant antimicrobial efficacy via contact killing owe to the presence of integrated biocidal metal moiety, which represents that the MPMs are safe for water disinfection.

Multi-element Contamination and Health Risks in Green Leafy Vegetables from Ambagarh Chowki, Chhattisgarh, India.

Leafy plants are commonly consumed as vegetables in India due to their high nutrient and vitamin content. This study, conducted in Ambagarh Chowki (India), investigated the accumulation potential of 52 elements (including Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Sr, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn) in seven leafy vegetable species, namely Amaranthus tricolor L., Corchorus olitorius L., Cordia myxa L., Hibiscus sabdariffa L., Ipomoea batatas (L.) Lam., Moringa oleifera Lam., and Spinacia oleracea L. Technique: Inductively coupled plasma mass spectrometry (ICP-MS) was employed for analysis. The maximum concentrations of elements such as Al, Ba, Be, Bi, Cd, Co, Cr, Fe, Ga, Ge, Li, Mn, Ni, Pb, Sb, Th, Tl, U, V, W, and REEs were observed in S. oleracea leaves, indicating their highest accumulation potential. In contrast, the maximum concentrations of As were found in H. sabdariffa leaves; Ca and Si in M. oleifera leaves; Mg, Sr, and Mo in A. tricolor leaves; and P, K, Cu, and Zn in C. myxa leaves, respectively. Twenty-one elements (Cr, Cd, Pb, Ni, Co, V, Cu, Zn, Fe, Mn, Th, Sb, Ba, Be, Li, Sr, Tl, U, Se, Sn, and REEs) exceeded permissible limits set by the WHO. The elevated hazard index values indicated significant non-carcinogenic effects. The sources of these elements could be attributed to a combination of geological factors and agricultural practices. This study highlights the need for further investigation into the potential health implications of consuming these vegetables in the aforementioned region.

Contamination, speciation, and health risk assessment of arsenic in leafy vegetables in Ambagarh Chowki (India).

Green leafy vegetables are essential for a balanced diet, providing vital nutrients for overall well-being. However, concerns arise due to contamination with toxic substances, such as arsenic, posing risks to food safety and human health. This study analyzes inorganic (iAs), monomethyl (MMA), and dimethyl arsenic (DMA) in specific leafy vegetables (Amaranthus tricolor L., Corchorus olitorius L., Cordia myxa L., Hibiscus sabdariffa L., Ipomoea batatas (L.) Lam., Moringa oleifera Lam., and Spinacia oleracea L.) grown in the heavily polluted Ambagarh Chouki region, Chhattisgarh, India. Concentrations of DMA, MMA, and iAs ranged from 0 to 155, 0 to 7, and 131 to 3579 mg·kg-1, respectively. The health quotient (HQ) for iAs ranged between 0.37 and 3.78, with an average value of 2.58 ± 1.08.

Dietary supplementation with omega-3 polyunsaturated fatty acids ameliorates acute pneumonia induced by Klebsiella pneumoniae in BALB/c mice.

The immune benefits associated with the optimal intake of dietary fatty acids are widely known. The objective of the present investigation was to elucidate the role of omega-3 polyunsaturated fatty acids (n-3 PUFA) food source on acute pneumonia induced by Klebsiella pneumoniae. Three different n-3 PUFA preparations (cod liver oil, Maxigard, and flaxseed oil) were orally supplemented and infection was induced in different groups of experimental mice. Mice fed olive oil and normal saline served as oil and saline controls, respectively. After 2 weeks of fatty acid feeding, no effect on the establishment of infection was observed when acute pneumonia was induced in animals. On the other hand, 6 weeks of n-3 PUFA administration was found to improve resistance in mice, as reduced lung bacterial load coupled with significant improvement in pathology was seen in infected mice. Alveolar macrophages collected from all 3 groups of mice fed n-3 PUFA exhibited a significant decrease in the level of apoptosis following infection with K. pneumoniae and an enhanced in vitro phagocytic potential for the pathogen. Lower lung levels of nitric oxide, malondialdehyde, and lactate dehydrogenase were associated with a decrease in the severity of tissue damage. There was a significant increase in the lung levels of pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß)). No significant change was observed in the levels of interleukin-10 (IL-10). This study highlights that dietary n-3 PUFA supplementation exerts an overall beneficial effect against acute experimental pneumonia. This mechanism is operative through upregulation of nonspecific and specific immune defenses of the host.

Impact of hydraulic loading rate and media type on removal of bulk organic matter and nitrogen from primary effluent in a laboratory-scale soil aquifer treatment system.

The effect of hydraulic loading rate (HLR) and media type on the removal of bulk organic matter and nitrogen from primary effluent during soil aquifer treatment was investigated by conducting laboratory-scale soil column studies. Two soil columns packed with silica sand were operated at HLRs of 0.625 and 1.25 m/d, while a third column was packed with dune filtering material and operated at HLR of 1.25 m/d. Bulk organic matter was effectively removed by 47.5 ± 1.2% and 45.1 ± 1.2% in silica sand columns operated at 0.625 and 1.25 m/d, respectively and 57.3 ± 7.6% in dune filtering material column operated at 1.25 m/d. Ammonium-nitrogen reduction of 74.5 ± 18.0% was achieved at 0.625 m/d compared to 39.1 ± 4.3% at 1.25 m/d in silica sand columns, whereas 49.2 ± 5.2% ammonium-nitrogen reduction was attained at 1.25 m/d in the dune filtering material column. Ammonium-nitrogen reduction in the first 3 m was assumed to be dominated by nitrification process evidenced by corresponding increase in nitrate. Part of the ammonium-nitrogen was adsorbed onto the media, which was observed at higher rates between 3 and 5 m in silica sand column operated at HLR of 0.625 m/d and dune filtering material column operated at 1.25 m/d compared to 1.25 m/d silica.

Thin film poly(vinyl alcohol)-polysulfone composite membranes based on recycled polysulfone: salt separation performances.

Poly(vinyl alcohol) (PVA)-coated membranes on polysulfone (Ps) (Memb-Pv) were cross-linked using the dibasic maleic acid. The tailoring of membrane properties (viz. hydrophilicity, permeability) develops through the ester linkage due to cross-linking of PVA and maleic acid (MA). Series of Ps asymmetric membranes were prepared using the successive stages of phase inversion of Ps materials. The recyclability approaches of polysulfone (Ps) pertained. The characteristics and transport properties of all the membranes are evaluated. FTIR-ATR, scanning electron (SEM), and atomic force microscopy (AFM) are used for the structural characterization of the membranes. The salient features of Memb-Pv composite membranes support promising results in desalination. The work aimed to highlight the trade-off between the flux and selectivity of composite membranes' salts (bi-/monovalent) through the recycled Ps matrix. The number of recycling stages influences the salt separation performance. The sulfate rejection differs from Memb-IPv (93.26%) to Memb-IVPv (86.70%) for water-I matrix using 2500 mg/L. The defluoridation potential of the membranes is also convincing. The defluoridation performance of Memb-IPv is 87% for 10 mg/L. A significant dimension is added regarding salt separation performance's dependence on the water matrices' nature. The decrease in fluoride separation is ~ 1-3% for the water-2 matrix as the TDS increases.

Reverse vaccinology approach to design a vaccine targeting membrane lipoproteins of Salmonella typhi.

Typhoid fever caused by Salmonella is one of the major health issues worldwide, resulting in millions of cases and has very high rates of morbidities. The therapeutic approaches need to be updated for the effective elimination of the bacterial pathogen. The designing of the multiepitope vaccine against Salmonella using comparative proteomics and reverse vaccinology has covered up all the epitopes that induce sufficient immune responses in the host body. Out of the 4293 proteins, 15 outer membrane proteins have been selected based on their antigenicity, low transmembrane helix (<1), and virulence-associated factors. With the help of the reverse vaccinology approach, the epitopes of MHC Class I, Class II, and B-cell with antigenic, low toxicity, and that have the potential to generate immunogenic response have been identified. Based on the comparative analysis of all the epitopes, a multiepitope-based construct has been designed. Based on physicochemical properties and docking scores for HLA and TLR4, the VC5 construct has been selected, and the molecular dynamic simulation studies have confirmed their interaction. The dissociation constant of the VC5 and TLR4 was found to be 3.1 x 10-9. Different immune cell activation has been analyzed, representing the potentiality of the VC5 construct as an effective vaccine target. In silico cloning of VC5 in pET28a has also been performed, which requires experimental validation. Therefore, the present study designs a multi-epitope vaccine VC5 targeted to the membrane lipoproteins of Salmonella typhi.Communicated by Ramaswamy H. Sarma.

One-pot facile approach to design an efficient macro-porous polymeric matrix to remediate Hg(II)and Pb(II) from aqueous medium and its performance evaluation study by mathematical modelling.

In the present scenario discharge of heavy-metal ions into water bodies is a global threat that is causing serious health hazards even in low concentrations. Thus, in order to remediate the heavy-metal [Hg(II) and Pb(II)] toxicity, an organic-inorganic hybrid functional porous metallo-polymeric network i. e, poly(Zirconyl methacrylate-co-1-vinyl imidazole) (pZrVIm) was fabricated via one-pot facile synthesis approach. The pZrVIm architecture has shown high removal efficiency for Hg(II) and Pb(II) aqueous medium even in extremely low quantities. Advanced instrumental techniques were used to characterize the structural and morphological characteristics of pZrVIm. Different experimental variables i.e., reaction time, pH, initial feed concentration, co-ion effects etc. were explored to examine adsorption behaviour. The maximum adsorption capacities (qmax) of pZrVIm5 were calculated as 168.06 and 162.34 mg g-1 for Hg(II) and Pb(II) respectively by the Langmuir isotherm model. Data from isotherms showed that monolayer adsorption on a homogeneous surface is the rate-limiting stage and followed pseudo-second-order kinetic process. The Artificial Neural Network (ANN) modelling was used to validate kinetics and isotherm data which revealed high accuracy of the model with correlation coefficient values (R = 0.99). Various types of isotherm models such as Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Redlich-Peterson, Toth and Koble-Corigen have been studied to determine the adsorption phenomena. The pore diffusion model revealed breakthrough time of 91 h and 84 h, Hg(II) and Pb(II) with the feed concentration of 15 mg L-1 respectively. The study revealed that pZrVIm5 has great potential for heavy metal ions remediation for water treatment.

Construction of arsenic selective chelating resin with iron precursor for removal of low-concentration arsenic: Breakthrough modeling and field deployment.

The presence of exorbitant arsenic contamination in the aquatic environment causes astronomically immense health quandaries affecting millions of people, which may lead to death in the case of prolonged indigestion of arsenic-containing drinking water. Herein, we are reporting porous chelating resin with an iron precursor for the removal of arsenic ions from water. Weak acid cation resin was functionalized under varying experimental conditions to get a suitable resin with high arsenic uptake. The theoretical results revealed that the maximum Langmuir adsorption capacities of 3.27 mg g-1 and 1.13 mg g-1 were achieved for As(V) and As(III), respectively. The kinetics of adsorption followed the pseudo-second-order (PSO) model with a high determination coefficient (R2) of 0.9963 and 0.9895 for As(V) and As(III), respectively. The Adams-Bohart, Thomas, Yoon-Nelson, and Pore diffusion models were used to identify the breakthrough curve in the fixed bed adsorption column. The column performance improved with a larger bed height (55 cm), low concentration of influent (0.25 mg L-1), and low flow rate of influent (80 mL min-1). Under this condition, the breakthrough time and exhaustion time were 314 min and 408 min for As(V) and 124 min and 185 min for As(III), respectively.

Nerve fibre morphometry with transmission electron microscopy: Application of the nucleator probe in ImageJ.

Stereology and semiautomated binary image histomorphometry are two common methods used for morphometry of nerve fibres. Nucleator probe can be used for the estimation of morphometric parameters like diameter, perimeter, area and volume of a structure that is approximately either a circle or a sphere. In this study, we estimated these parameters with the help of ImageJ software on calibrated transmission electron micrographs. We procured samples of the cochlear nerve (CN) during winter months, within 6-12 hours of death, to reduce post-mortem autolytic changes. The temporal bones containing the CN were fixed by immersion in chilled paraformaldehyde. After dissecting out from the petrous part of the temporal bone, the CN were osmicated and processed for embedding in resin. From the resin blocks, silver coloured (70 nm) ultrathin sections were cut and picked on 300-mesh copper grids, stained with uranyl acetate and lead citrate and viewed under Tecnai G2-20 transmission electron microscope. The transmission electron micrographs had scale bars embedded into them by the software at the time of imaging, and the morphometric parameters of randomly selected nerve fibres were measured using the ImageJ software. The ImageJ software could become a low-cost and dependable tool for nerve fibre morphometry.•Nucleator probe is used for the estimation of morphometric parameters like diameter, perimeter, area or volume•Morphometric parameters were estimated by the ImageJ software on calibrated transmission electron micrographs•The ImageJ software could become a low-cost and dependable tool for nerve fibre morphometry.

Kinetics of Severe Acute Respiratory Syndrome Corona Virus-2 Specific Antibody in Corona Virus Diease 2019.

BACKGROUND: Severe Acute Respiratory Syndrome Corona Virus 2019, a novel coronavirus first reported from China in 2019, is the causative agent of pandemic corona virus disease 2019. Antibody response and its dynamics may provide information about natural immunity conferred upon by corona virus disease 2019. METHODS: A health-center-based follow up study of confirmed Severe Acute Respiratory Syndrome Corona Virus-2 infected patients was conducted from December 2020 to June 2021. Patients were followed up to period of 28 weeks during the study. An electrochemiluminescence immunoassay was used to test antibodies elicited by Severe Acute Respiratory Syndrome Corona Virus-2. Socio-demographic and clinical information was collected from each patient. RESULTS: A total of 40 patients (18 males and 22 females) were enrolled in the study, with 90 % seropositivity of SARS-CoV-2 antibody. Antibody level was tracked up to 28 weeks following the infection, and persistence was observed till the end. Antibody level peaked on the 3rd to 4th month, after symptom onset. The male population was found to have higher antibody levels compared to females. Age-wise trend analysis showed lower antibody levels in the younger people (15-30 years) than those older (31-60 years). CONCLUSIONS: We demonstrated that Severe Acute Respiratory Syndrome Corona Virus-2 specific antibodies in corona virus disease 2019 patients persist for at least 28 weeks, peaking at 13 to 20 weeks. Statistically, there was no correlation of antibody levels with the age and sex of individuals. Further study on a larger population is needed for determining long-term immunity.

Synchronous Removal of Arsenic and Fluoride from Aqueous Solution: A Facile Approach to Fabricate Novel Functional Metallopolymer Microspheres.

Concurrence of arsenic (As) and fluoride (F-) ions in groundwater is a serious concern due to their fatal effects. Herein, an attempt was made to fabricate quaternized poly(zirconyl dimethacrylate-co-vinylbenzyl chloride)] (ZrVBZ), a metallopolymeric microsphere in three-dimensional shape with a porous texture. The synthesized ZrVBZ was utilized for the synchronal removal of As and F- from water. Techniques such as Fourier transform infrared spectroscopy, 13C-nuclear magnetic resonance, scanning electron microscopy, and Brunauer-Emmett-Teller surface area were used to characterize the ZrVBZ. The maximum adsorption capacity of ZrVBZ for both fluoride and arsenic (q max F-: 116.5 mg g-1, q max As(V): 7.0 mg g-1, and q max As(III): 6.5 mg g-1) at given experimental conditions (adsorbents' dose: 0.250 g L-1, feed of F-: 50 mg L-1, As(V)/As(III): 2000 µg L-1, and pH: 7.0 ± 0.2) was ascribed to the porous spherical architecture with dual functional sites to facilitate adsorption. The adsorption followed pseudo-second-order kinetics with a correlation coefficient of 0.996, 0.997, and 0.990 for F-, As(V), and As(III), respectively. The isotherm data fitted to the Langmuir isotherm model, and the maximum capacity was 121.5, 7.246, and 6.68 mg g-1 for F-, As(V), and As(III), respectively. The results of this study indicated that ZrVBZ could be used as an effective adsorbent for the simultaneous removal of F-, As(V), and As(III) from an aqueous medium.

The ultrastructural study of human cochlear nerve at different ages.

Ultrastructural and molecular changes in the myelin of the cochlear nerve (CN) have been associated with decreased hearing-acuity with increasing age. But most of these are animal studies or with very few human samples. Hence, we studied the ultrastructure of the human CN at different ages. We obtained samples of CN from persons, who at the time of death belonged to young, middle or old age-groups; defined as ≤ 30, 31 to 50, and ≥ 51 years of age, respectively. These were processed for viewing under a transmission electron microscope (TEM). Morphology and morphometry were assessed after blinding the observer. Measurements of diameter (whole nerve fibre, axon), myelin thickness and calculation of G-ratio were made on calibrated images using ImageJ software. K-Means cluster analysis was performed based on total and inner nerve fibre area. Middle and old age CN showed degenerating axons, splitting of myelin sheath and myelin balloons. Between the middle and old age groups there was significant decrease in axon diameter (p<0.001), inner nerve fibre area (p<0.001), myelin thickness (p<0.001), nerve fibre diameter (p<0.001), and G-ratio (p<0.001). By clustering, we identified three distinct populations of myelinated nerve fibres: large, medium and small. The large fibres (by size), seen in the young, disappeared in the old age-group. We were unable to find any unmyelinated nerve fibres in this study. The morphological deterioration CN fibres may be a visible sign of molecular degeneration and contribute to decreased hearing-acuity.

A comparative study of induction of pneumonia in mice with planktonic and biofilm cells of Klebsiella pneumoniae.

In the present study, the course of acute pneumonia in normal BALB/c mice infected by intranasal inoculation of planktonic and preformed biofilm cells (3 days old) of Klebsiella pneumoniae B5055 was studied and compared. With both cell forms the peak of infection was observed on the third post infection day, as assessed on the basis of lung bacterial load and corresponding pathology. There was an intense neutrophil infiltration in bronchoalveolar lavage fluid. Tissue damage was assessed on the basis of increased amounts of nitrite, malondialdehyde and lactate dehydrogenase in lung homogenates. The phagocytic potential of alveolar macrophages was lower in biofilm cell-induced infection than in that induced by planktonic cells. Biofilm cell induced infection generated significantly greater production of tumor necrosis factor-α and interleukin-1ß on the third and fifth days of infection, respectively. Production of interleukin-10 was, however, variable. There was no significant difference in the ability of planktonic and biofilm cell forms of K. pneumoniae to induce acute pneumonia in mice in terms of bacterial counts and histopathological changes. However, biofilm cell-induced infection showed delayed clearance as compared to infection induced with the planktonic form.