Epidemiological, clinical, and laboratory characteristics of human granulocytic anaplasmosis in North India.

Human granulocytic anaplasmosis (HGA) is an emerging, rickettsial tick-borne disease caused by Anaplasma phagocytophilum. Sero-epidemiological data demonstrate that this pathogen has a worldwide distribution. The diagnosis of HGA requires a high index of clinical suspicion, even in endemic areas. In recent years, HGA has increasingly been reported from Asia and described in China, Japan, and Korea. We serologically and molecularly screened 467 patients with clinical suspicion of Anaplasmosis. The present study describes the epidemiology, clinical, and laboratory details of 6 confirmed and 43 probable cases of human granulocytic anaplasmosis. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection. The HGA patients without severe complications had excellent treatment responses to doxycycline. The emergence of this newly recognized tick-borne zoonotic HGA in North India is a significant concern for public health and is likely underdiagnosed, underreported, and untreated. Hence, it is also essential to establish a well-coordinated system for actively conducting tick surveillance, especially in the forested areas of the country.IMPORTANCEThe results of the present study show the clinical and laboratory evidence of autochthonous cases of Anaplasma phagocytophilum in North India. The results suggest the possibility of underdiagnosis of HGA in this geographical area. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection.

Small molecule bio-signature in childhood intra-thoracic tuberculosis identified by metabolomics.

The diagnosis of pediatric tuberculosis (TB) remains a major challenge, hence the evaluation of new tools for improved diagnostics is urgently required. We investigated the serum metabolic profile of children with culture-confirmed intra-thoracic TB (ITTB) (n = 23) and compared it with those of non-TB controls (NTCs) (n = 13) using proton NMR spectroscopy-based targeted and untargeted metabolomics approaches. In targeted metabolic profiling, five metabolites (histidine, glycerophosphocholine, creatine/phosphocreatine, acetate, and choline) differentiated TB children from NTCs. Additionally, seven discriminatory metabolites (N-α-acetyl-lysine, polyunsaturated fatty acids, phenylalanine, lysine, lipids, glutamate + glutamine, and dimethylglycine) were identified in untargeted metabolic profiling. The pathway analysis revealed alterations in six metabolic pathways. The altered metabolites were associated with impaired protein synthesis, hindered anti-inflammatory and cytoprotective mechanisms, abnormalities in energy generation processes and membrane metabolism, and deregulated fatty acid and lipid metabolisms in children with ITTB. The diagnostic significance of the classification models obtained from significantly distinguishing metabolites showed sensitivity, specificity, and area under the curve of 78.2%, 84.6%, and 0.86, respectively, in the targeted profiling and 92.3%, 100%, and 0.99, respectively, in the untargeted profiling. Our findings highlight detectable metabolic changes in childhood ITTB; however, further validation is warranted in a large cohort of the pediatric population.

Tick-tock, beat the clock: comparative analysis of disc diffusion testing with 6-, 10-, and 24-h growth for accelerated antimicrobial susceptibility testing and antimicrobial stewardship.

Disc diffusion testing by Kirby-Bauer technique is the most used method for determining antimicrobial susceptibility in microbiological laboratories. The current guidelines by The Clinical and Laboratory Standards Institute (CLSI) 2022 specify using an 18- to 24-h growth for testing by disc diffusion. We aim to determine if using an early growth (6 h and 10 h) would produce comparable results, thus ultimately leading to reduced turnaround time. Six-hour, 10-h, and 24-h growths of 20 quality control strains and 6-h and 24-h growths of 48 clinical samples were used to perform disc diffusion testing using a panel of appropriate antimicrobial agents. Disc diffusion zone sizes were interpreted for all and comparative analyses were performed to determine categorical agreement, minor errors (mE), major errors (ME), and very major errors (VME) according to CLSI guidelines. On comparing with the standard 24 h of incubation, disc diffusion from 6-h and 10-h growths of quality control strains showed 94.38% categorical agreement, 5.10% mE, 0.69% MEs, and no VMEs. Disc diffusion testing for the additional 40 clinical samples yielded a similarly high level of categorical agreement (98.15%) and mE, ME, and VME of 1.29%, 1.22%, and 0% respectively. Disc diffusion testing using early growth is a simple and accurate method for susceptibility testing that can reduce turnaround time and may prove to be critical for timely patient management.

Bacteriophages as therapeutic & disinfectant agents to tackle multidrug-resistant Acinetobacter baumannii.

Background & objectives: Multidrug-resistant (MDR) Acinetobacter baumannii is a serious threat for human health worldwide. The studies on agents targeting A. baumannii are imperative due to identified A. baumannii co-infections in COVID-19. Bacteriophages are promising antibacterial agents against drug-resistant bacteria. This study intended to isolate bacteriophages against MDR A. baumannii from the water of river Ganga, to be used potentially as therapeutic and disinfectant particles. Methods: Acinetobacter phages were isolated from the Ganga water collected from Kanpur and further tested on 50 MDR A. baumannii isolates to determine host range. The phages were morphologically characterized by transmission electron microscopy. The disinfectant property of the isolated phages was tested by spraying of bacteriophage cocktail on MDR A. baumannii contaminated plastic surface, analyzed by colony-forming unit (CFU) and bioluminescence assay (adenosine triphosphate monitoring). Results: A total of seven bacteriophages were isolated against MDR A. baumannii. The bacteriophages lysed three MDR A. baumannii isolates out of 50 tested, showing narrow host range. Electron microscopy revealed hexagonal heads and long tails of bacteriophages, belonging to order Caudovirales. The bacteriophage cocktail reduced the MDR A. baumannii load efficiently on plastic surface, evidenced by reduction in CFUs and bioluminescence. Interpretation & conclusions: The findings of this study suggest that the isolated bacteriophages are potential lytic agents for MDR A. baumannii clinical isolates, and may be used as potential therapeutic agents as well as disinfectant to combat MDR A. baumannii with due consideration to phage host specificity, with further characterization.

Evaluation of SARS-CoV-2 Specific IgG Antibodies in Individuals Vaccinated with Covaxin (BBV152): An Independent Assessment.

Post vaccination with Covaxin (BBV152), Serum from healthcare professionals of Microbiology Department at apex tertiary referral hospital of India were tested for SARS-CoV-2 specific IgG antibodies. 70% individuals at 14-30 days, 63.1% individuals at 30-60 days but only 36.8% individuals at 60-90 days after second dose of vaccine had detectable SARS-CoV-2 spike protein specific IgG antibodies. However, 80% individuals at 14-30 days, 89.4% individuals at 30-60 days while 94.7% individuals at 60-90 days after second dose of vaccine had detectable SARS-CoV-2 whole cell antigen specific IgG antibodies. Males were lacking SARS-CoV-2 spike protein specific IgG antibodies in higher proportion than females and had lower index wherever detected. Age and co-morbidities were non-significant factors for post vaccination IgG response but not in breakthrough infection. 8.3% individuals developed mild COVID-19 symptoms post 14-90 days of second dose and none had severe COVID-19. SARS-CoV-2 spike protein specific IgG antibodies induced by Covaxin are drastically reduced in 60-90 days among fully vaccinated individuals which could be a potential risk for breakthrough SARS-CoV-2 infection, if not severe COVID-19. It may be essential to have additional antigenic stimulations/boosters for continued protection.

Virulence gene mutations as a differentiator of clinical phenotypes: insights from community-acquired uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) remains an important cause of urinary tract infection during pregnancy. Multiple molecular virulence determinants and antibiotic resistant genes facilitate its pathogenesis and virulence phenotype. Hence it is hypothesized that there will be considerable variation in genes among the isolates from symptomatic as well as asymptomatic bacteriuria (ABU) during pregnancy. The aim of this study was to decipher the genetic variation among the two phenotypes. Six different UPEC isolates collected from urine specimens of consecutive pregnant females (five, symptomatic bacteriuria and one, ABU) were tested for their growth kinetics, and biofilm formation. A total of 87 virulence determinants and 56 antibiotic resistance genes were investigated using whole-genome sequencing, to identify putative drives of virulence phenotype. In this analysis, we identified eight different types of fully functional toxin antitoxin (TA) systems [HipAB, YefM-YoeB, YeeU-YeeV (CbtA), YhaV-PrlF, ChpBS, HigAB, YgiUT and HicAB] in the isolates from symptomatic bacteriuria; whereas partially functional TA system with mutations were observed in the asymptomatic one. Isolates of both the groups showed equivalent growth characteristics and biofilm-formation ability. Genes for an iron transport system (Efe UOB system, Fhu system except FhuA) were observed functional among all symptomatic and asymptomatic isolates, however functional mutations were observed in the latter group. Gene YidE was observed predominantly associated with the biofilm formation along with few other genes (BssR, BssS, YjgK, etc.). This study outlines putative critical relevance of specific variations in the genes for the TA system, biofilm formation, cell adhesion and colonization among UPEC isolates from symptomatic and asymptomatic bacteriuria among pregnant women. Further functional genomic study in the same cohort is warranted to establish the pathogenic role of these genes.

HIV testing & diagnosis in 2020 at the apex tertiary referral hospital of India: impact of COVID-19 pandemic.

Timely HIV testing and diagnosis are necessary to prevent the development of AIDS and interrupt its transmission in society. We collected the data on HIV testing and diagnosis in 2020 and compared it with preceding years to examine how COVID-19 pandemic-related restrictions impacted HIV services. The number of people who underwent HIV testing at the apex tertiary referral hospital of India in 2020 reduced by 57% compared to 2019 or the average/year during 2019-2016. Hence, the diagnosis of new HIV infections decreased by 52% compared to 2019 and 54% compared to the average/year during 2019-2016. Provider-initiated testing and diagnosis were more affected than client-initiated. There was a non-significant change in the rate of HIV detection among tested individuals. The male testing saw a more notable drop than female testing. HIV testing between ≥50 years and ≤14 years was more affected than other age groups. The transmission via regular partner/spouse increased, whereas it decreased via heterosexual commercial sex workers.

Antibiotic resistance of uropathogens among the community-dwelling pregnant and nonpregnant female: a step towards antibiotic stewardship.

BACKGROUND: Indiscriminate and widespread use of antibiotics has resulted in emergence of many antibiotic-resistant organisms. Antibiotic administration during pregnancy is mostly avoided, unless there is compelling medical condition. We hypothesized that the uropathogens isolated from pregnant women would be more susceptible to antibiotics compared to those isolated from nonpregnant women, thus will be helpful in formulating separate empiric guideline for pregnant women based on the resistance pattern. METHODS: This was a prospective cross-sectional study conducted over a period of 2 years in which females with the clinical diagnosis of either cystitis or asymptomatic bacteriuria during pregnancy were included from the community settings. Uropathogen species and their antimicrobial resistance pattern were compared between the pregnant and nonpregnant groups. After accounting for centre-to-centre variation and adjusting for age and socio-economic status, the adjusted odds ratio for antibiotic resistance was calculated and compared between pregnant and nonpregnant women using logistic regression analysis. RESULTS: A total of 1758 women (pregnant: 43.3%; nonpregnant: 56.6%) were screened in the study over a period of 2 years, out of which 9.3% (163/1758) were having significant bacteriuria. Escherichia coli and Klebsiella pneumoniae were the two commonest uropathogen in both the groups; their prevalence being 83.6% in pregnant women and 85.2% in nonpregnant women, respectively. Resistance against ampicillin, cefixime, cefoxitin, ceftazidime, ceftriaxone and amoxicillin-clavulanic acid were found significantly lower in the pregnant women compared to nonpregnant. After adjusting the age and socio-economic status accounting for centre-to-centre variation, the odds of resistance for cefixime, amoxicillin-clavulanic acid and co-trimoxazole were found lower and statistically significant among the pregnant women group. CONCLUSIONS: The antimicrobial resistance was significantly higher among the community-dwelling nonpregnant women compared to pregnant women in case of few antibiotics. The study highlighted the need of building local antibiogram that could help to initiate the empirical treatment and thus prevent emergence of antimicrobial resistance.

An insight into the therapeutic potential of a novel lytic Pseudomonas phage isolated from the river Ganga.

AIM: Bacteriophages are effective natural antimicrobial agents against drug-resistant pathogens. Therefore, identification and detailed characterization of bacteriophages become essential to explore their therapeutic potential. This study aims to isolate and characterize a lytic bacteriophage against drug-resistant Pseudomonas aeruginosa. METHODS AND RESULTS: The Pseudomonas phage AIIMS-Pa-A1, isolated from the river Ganga water against drug-resistant P. aeruginosa, showed a clear lytic zone on spot assay. The phage revealed an icosahedral head (58.20 nm diameter) and a small tail (6.83 nm) under a transmission electron microscope. The growth kinetics showed an adsorption constant of 1.5 × 10-9 phage particles cell-1 ml-1 min-1 and a latent period of approximately 15 min with the burst size of 27 phages per infected cell. The whole-genome sequencing depicted a GC-rich genome of 40.97 kb having a lysis cassette of holin, endolysin and Rz protein, with features of the family Autographiviridae. The comparative genome analysis, Ortho-average nucleotide identity value, and phylogenetic analysis indicated the novelty of the phage AIIMS-Pa-A1. CONCLUSIONS: The study concludes that the Pseudomonas phage AIIMS-Pa-A1 is a novel member of the Autographiviridae family, truly lytic in nature for drug-resistant P. aeruginosa. SIGNIFICANCE AND IMPACT OF THE STUDY: The Pseudomonas phage AIIMS-Pa-A1 is having promising potential for future therapeutic intervention to treat drug-resistant P. aeruginosa infections.

Th1/Th2/Th17 Cytokine Profile among Different Stages of COVID-19 Infection.

Aim: To characterize Th1/Th2/Th17 cytokine profile (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) among different stages of COVID-19 infection. Methods: This was a cross-sectional study which included six healthy individuals and 68 patients who were admitted with COVID-19 in the Department of Medicine, at All India Institute of Medical Sciences, New Delhi, from July 2020 to September 2020. Patients were categorized into mild, moderate, and severe COVID-19 groups, and serum samples were drawn for the measurement of Th1/Th2/Th17 cytokines (IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) which was done by BD™ Cytometric Bead Array. Results: All the cytokines showed dynamic expression in the COVID-19 group, of which only IL-6 was statistically significant. Among the three severity groups of COVID-19, increased severity did not transform into increased cytokine level, with the exception for IL-6, which was statistically significant. Conclusions: In our small sample study, six cytokines expressions were evaluated however most of them were elevated in COVID-19 patients but were not statistically significant except IL-6.

Exploring the clinical variables among drug-dependent HIV-Positive patients: Implications for treatment strategies.

This study explored the profile of HIV positive patients seeking treatment at a tertiary care addiction treatment facility. A retrospective study was done to collet detailed information on clinical characteristics: drug use (type, age of initiation, duration), general medical condition and past treatment history. The study included 138 patients with mean (SD) age 30.2 (8.3) years. Opioid dependence with injecting drug use (IDU) was diagnosed in 97% of the patients. The median age of injecting onset was 24.5 years (IQR 20-31 years). The most frequently injected substances were pheniramine (60.1%) and buprenorphine (59.4%). Past treatment seeking was reported by 57% patients and interestingly they were less likely to present any medical condition (2 =69.611, p < 0.001). Variability in the age of onset of drug use indicates the need for broad based approach to prevent IDU and motivation to seek treatment may lead to better health conditions.

A Rare Mutation in an Infant-Derived HIV-1 Envelope Glycoprotein Alters Interprotomer Stability and Susceptibility to Broadly Neutralizing Antibodies Targeting the Trimer Apex.

The envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) is the sole target of broadly neutralizing antibodies (bnAbs). Several mechanisms, such as the acquisition of mutations, variability of the loop length, and alterations in the glycan pattern, are employed by the virus to shield neutralizing epitopes on Env to sustain survival and infectivity within the host. The identification of mutations that lead to viral evasion of the host immune response is essential for the optimization and engineering of Env-based trimeric immunogens. Here, we report a rare leucine-to-phenylalanine escape mutation (L184F) at the base of hypervariable loop 2 (population frequency of 0.0045%) in a 9-month-old perinatally HIV-1-infected infant broad neutralizer. The L184F mutation altered the trimer conformation by modulating intramolecular interactions stabilizing the trimer apex and led to viral escape from autologous plasma bnAbs and known N160 glycan-targeted bnAbs. The L184F amino acid change led to the acquisition of a relatively open trimeric conformation, often associated with tier 1 HIV-1 isolates and increased susceptibility to neutralization by polyclonal plasma antibodies of weak neutralizers. While there was no impact of the L184F mutation on free virus transmission, a reduction in cell-to-cell transmission was observed. In conclusion, we report a naturally selected viral mutation, L184F, that influenced a change in the conformation of the Env trimer apex as a mechanism of escape from contemporaneous plasma V2 apex-targeted nAbs. Further studies should be undertaken to define viral mutations acquired during natural infection, to escape selection pressure exerted by bnAbs, to inform vaccine design and bnAb-based therapeutic strategies.IMPORTANCE The design of HIV-1 envelope-based immunogens capable of eliciting broadly neutralizing antibodies (bnAbs) is currently under active research. Some of the most potent bnAbs target the quaternary epitope at the V2 apex of the HIV-1 Env trimer. By studying naturally circulating viruses from a perinatally HIV-1-infected infant with plasma neutralizing antibodies targeted to the V2 apex, we identified a rare leucine-to-phenylalanine substitution, in two out of six functional viral clones, that destabilized the trimer apex. This single-amino-acid alteration impaired the interprotomeric interactions that stabilize the trimer apex, resulting in an open trimer conformation and escape from broadly neutralizing autologous plasma antibodies and known V2 apex-directed bnAbs, thereby favoring viral evasion of the early bnAb response of the infected host. Defining the mechanisms by which naturally occurring viral mutations influence the sensitivity of HIV-1 to bnAbs will provide information for the development of vaccines and bnAbs as anti-HIV-1 reagents.

Clinical and molecular epidemiology of vancomycin-resistant Enterococcus faecium bacteremia from an Indian tertiary hospital.

We determined the clinical and molecular epidemiology of emerging nosocomial vancomycin-resistant Enterococcus faecium (VREfm)-causing serious bloodstream infections (BSIs) and the correlations between antibiotic resistance and virulence determinants among isolates. All isolates were confirmed by molecular methods (16SrRNA and E. faecium ddl genes) and tested for disk diffusion. PCR was used to detect aac(6')-aph(2″), vanA and vanB resistance genes, and asa1, cylA, ace, esp, gelE and hyl virulence genes. VREfm and high-level gentamicin-resistant (HLGR) representative isolates were selected to characterize by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Of 173 isolates, 73 (42.2%), 146 (84.4%), and 0 (0.0%) were vanA-containing VREfm, aac(6')-aph(2″)-positive HLGR, and vanB-positive. Independent predictors of VREfm infection were hematological malignancies (P = 0.001) and previous hospitalizations (P = 0.007). Observed mortality rate was 34.7%. Independent predictors of BSI-related mortality were endotracheal intubations (P < 0.001), gastrointestinal diseases (P = 0.002), and pulmonary disease (P < 0.001). All VREfm were resistant to vancomycin, teicoplanin, ciprofloxacin, and erythromycin. The esp, hyl, ace, asa1, cylA, and gelE genes were detected at 55.9, 22.5, 2.9, 2.3, 1.7, and 1.2%, respectively. The esp gene was significantly associated with VREfm compared to VSEfm (P = 0.001). PFGE analysis revealed 23 clones, with 7 major clones. The MLST analysis revealed the following five sequence types: ST80, ST17, ST117, ST132, and ST280, all belonging to CC17. The emergence and expansion of VREfm CC17 with limited antibiotic options in our hospital present a serious public health menace and represent challenges to infection control.

Coronin-1 levels in patients with tuberculosis.

Background & objectives: Despite advances in diagnostics and therapeutics, tuberculosis (TB) is widely prevalent and contributes to a significant burden of illness in both developing and developed nations. The present study was aimed to assess the role of coronin in TB patients and healthy controls. Coronin is a leucocyte-specific protein that is actively recruited in mycobacterial phagolysosomes, where it inhibits lysosomal delivery of Mycobacterium by activating a calcium-dependent phosphatase-calcineurin. Methods: In the study, 100 newly diagnosed cases of TB (pulmonary and extra-pulmonary) and healthy controls were prospectively enrolled over one year and the levels of coronin-1a in these patients and controls were measured by quantitative PCR (qPCR). Results: A total of 100 TB patients and 100 healthy individuals as controls were assessed. There were 59 patients with extra-pulmonary TB (EPTB) and 41 of pulmonary TB (PTB). In 47 per cent of patients, corroborative histopathological evidence of TB was also available. Significantly higher values of coronin-1a were observed in TB patients (19.94±2.61) than in healthy controls (16.09±1.91) (P<0.001). Interpretation & conclusions: Coronin 1a appears to play an important role in the TB disease pathophysiology and agents developed against coronin may have a role in the treatment of TB. Further studies are required to assess if coronin-1a levels are elevated in non-tubercular infective a etiologies and whether these can be a potential drug target in patients with TB.

Multilocus Sequence Typing of Clinical Isolates of Cryptococcus from India.

Cryptococcosis is a life-threatening infection caused by Cryptococcus neoformans and C. gattii species complex. In the present study, to understand the molecular epidemiology of 208 clinical isolates of Cryptococcus from different parts of India, multilocus sequence typing (MLST) using ISHAM MLST consensus scheme for C. neoformans/C. gattii species complex was used. MLST analysis yielded a total of 10 Sequence Types (STs)-7 STs for C. neoformans and 3 for C. gattii species complex. The majority of isolates identified as C. neoformans belonged to molecular type VNI with predominant STs 31 and 93. Only 3 isolates of C. gattii species complex were obtained, belonging to ST58 and ST215 of VGI and ST69 of VGIV. Phylogenetic analysis revealed less diversity among the clinical Indian isolates compared to the global MLST database. No association between prevalent STs and HIV status, geographical origin or minimum inhibitory concentration (MIC) could be established.

Effect of combination antiretroviral therapy on human immunodeficiency virus 1 specific antibody responses in subtype-C infected children.

Protective antibody responses to human immunodeficiency virus (HIV)-1 infection evolve only in a fraction of infected individuals by developing broadly neutralizing antibodies (bnAbs) and/or effector functions such as antibody-dependent cellular cytotoxicity (ADCC). HIV-1 chronically infected adults and children on combination antiretroviral therapy (cART) showed a reduction in ADCC activity and improvement in HIV-1 specific neutralizing antibody (nAb) responses. Early initiation of cART in infected adults is found to be beneficial in reducing the viral load and delaying disease progression. Herein, we longitudinally evaluated the effect of cART on HIV-1 specific plasma ADCC and nAb responses in a cohort of 20 perinatally HIV-1 subtype-C infected infants and children ≤2 years of age, pre-cART and up to 1 year post-cART initiation. Significant reductions in HIV-1 specific plasma ADCC responses to subtype-C and subtype-B viruses and improvement in HIV-1 neutralization were observed in HIV-1 infected children 1 year post-cART initiation. A positive correlation between reduction in viral load and the loss of ADCC response was observed. This study provides information aiding the understanding of the effects of early initiation of cART on antibody effector functions and viral neutralization in HIV-1 infected children, which needs to be further evaluated in large cohorts of HIV-1 infected children on cART to plan future intervention strategies.

Viral Characteristics Associated with Maintenance of Elite Neutralizing Activity in Chronically HIV-1 Clade C-Infected Monozygotic Pediatric Twins.

Broad and potent neutralizing antibodies (bnAbs) with multiple epitope specificities evolve in HIV-1-infected children. Herein, we studied two antiretroviral-naive chronically HIV-1 clade C-infected monozygotic pediatric twins, AIIMS_329 and AIIMS_330, with potent plasma bnAbs. Elite plasma neutralizing activity was observed since the initial sampling at 78 months of age in AIIMS_330 and persisted throughout, while in AIIMS_329 it was seen at 90 months of age, after which the potency decreased over time. We evaluated potential viral characteristics associated with the varied immune profiles by generating single genome-amplified pseudoviruses. The AIIMS_329 viruses generated from the 90-month time point were neutralization sensitive to bnAbs and contemporaneous plasma antibodies, while viruses from the 112-month and 117-month time points were resistant to most bnAbs and contemporaneous plasma. AIIMS_329 viruses developed resistance to plasma neutralizing antibodies (nAbs) plausibly by N160 glycan loss and V1 and V4 loop lengthening. The viruses generated from AIIMS_330 (at 90 and 117 months) showed varied susceptibility to bnAbs and autologous contemporaneous plasma antibodies, while the viruses of the 112-month time point, at which the plasma nAb specificities mapped to the V2 glycan, V3 glycan, and CD4 binding site (CD4bs), were resistant to contemporaneous plasma antibodies as well as to most bnAbs. Chimeric viruses were constructed from 90-month-time-point PG9-sensitive AIIMS_329 and AIIMS_330 viruses with swapped V1V2 regions of their respective evolved viruses (at 112 and 117 months), which led to higher resistance to neutralization by PG9 and autologous plasma antibodies. We observed the evolution of a viral pool in the AIIMS_330 donor comprising plasma antibody neutralization-sensitive or -resistant diverse autologous viruses that may have contributed to the development and maintenance of elite neutralizing activity.IMPORTANCE Herein, we report the longitudinal development of bnAbs in a pair of chronically HIV-1 clade C-infected monozygotic pediatric twins, AIIMS_329 and AIIMS_330, who acquired the infection by vertical transmission. The plasma from both donors, sharing a similar genetic makeup and infecting virus, showed the evolvement of bnAbs targeting common epitopes in the V2 and V3 regions of the envelope, suggesting that bnAb development in these twins may perhaps be determined by specific sequences in the shared virus that can guide the development of immunogens aimed at eliciting V2 and V3 bNAbs. Characterization of the neutralization-sensitive and -resistant viruses coevolving with bNAbs in the contemporaneous AIIMS_330 plasma provides information toward understanding the viral alterations that may have contributed to the development of resistance to bnAbs. Further longitudinal studies in more monozygotic and dizygotic twin pairs will help in delineating the role of host and viral factors that may contribute to the development of bnAbs.

Structure based drug discovery and in vitro activity testing for DNA gyrase inhibitors of Salmonella enterica serovar Typhi.

The emerged resistance in Typhoidal Salmonella has limited the treatment options for typhoid fever. In this scenario, there is a need to find alternate treatment modalities against this pathogen. Amongst the therapeutic agents currently being used to treat enteric fever, quinolones have enjoyed considerable success since past three decades. These drugs act upon DNA gyrase and the acquired resistance is due to mutations at Ser83 and Asp87 of gyrase A subunit. In the present study DNA gyrase enzyme was targeted to seek out potential new inhibitors which are not affected by these mutations. Molecular modelling and docking studies were performed in Schrödinger's molecular modelling software. Homology model of DNA gyrase-DNA complex was built using templates 1AB4 and 3LTN. Molecular dynamic simulations were performed in SPC solvent for 100 ns. Total 17,900,742 drug like molecules were downloaded from ZINC library of chemical compounds. The Glide XP score of the compounds ranged from -5.285 to -13.692. All the ligands bound at the four base pair staggered nick in the DNA binding groove of DNA gyrase enzyme with their aromatic rings intercalating between the bases of two successive nucleotides stabilized by π - π stacking interactions. The binding pocket of DNA gyrase B comprising conserved residues Lys 447, Gly 448, Lys 449, Ile 450, Leu 451, Gln 465 and Val 467 interacts with the ligand molecules through van der Waals interactions. The MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration) and IC50 of the tested compounds ranged from 500 to 125 mg/L, 750 to 500 mg/L and 100 to 12.5 mg/L, respectively. The selected hits bind to quinolone binding pocket, but their mode of binding and conformation is different to fluoroquinolones, and hence, their binding is not affected by mutations at Ser83 or Asp87 positions. These lead compounds can be further explored as a scaffold to design inhibitors against DNA gyrase to bypass quinolone resistance.

Effect of Withania somnifer on CD38 expression on CD8+ T lymphocytes among patients of HIV infection.

CD38 on CD8 + T cells is considered a reliable marker of HIV disease progression. Withania somnifer, a traditional ayurvedic medicine, has Th1 immunomodulatory properties. PBMCs from 38 HIV patients were exposed to Withania somnifer root extract at standardized concentration. An overall decline in the percentage of CD38 expressing CD8 + T lymphocytes was observed, though the statistical significance was varied with different categories of HIV patients. Withania somnifer could have promising impact on HIV disease and therefore warrants a further study on larger parameters.

Current antibiotic use in the treatment of enteric fever in children.

Background & objectives: Antimicrobial resistance is a major challenge in the treatment of typhoid fever with limited choices left to empirically treat these patients. The present study was undertaken to determine the current practices of antibiotic use in children attending a tertiary care hospital in north India. Methods: This was a descriptive observational study in children suffering from enteric fever as per the case definition including clinical and laboratory parameters. The antibiotic audit in hospitalized children was measured as days of therapy per 1000 patient days and in outpatient department (OPD) as antibiotic prescription on the treatment card. Results: A total of 128 children with enteric fever were included in the study, of whom, 30 were hospitalized and 98 were treated from OPD. The mean duration of fever was 9.5 days at the time of presentation. Of these, 45 per cent were culture positive with Salmonella Typhi being aetiological agent in 68 per cent followed by S. Paratyphi A in 32 per cent. During hospitalization, the average length of stay was 10 days with mean duration of defervescence 6.4 days. Based on antimicrobial susceptibility ceftriaxone was given to 28 patients with mean duration of treatment being six days. An additional antibiotic was needed in six patients due to clinical non-response. In OPD, 79 patients were prescribed cefixime and additional antibiotic was needed in five during follow up visit. Interpretation & conclusions: Based on our findings, ceftriaxone and cefixime seemed to be the first line of antibiotic treatment for typhoid fever. Despite susceptibility, clinical non-response was seen in around 10 per cent of the patients who needed combinations of antibiotics.