SARS-CoV-2 infection and seropositivity among household contacts of laboratory confirmed cases of COVID-19 in residents of Delhi, India.

The transmission of respiratory pathogens, including SARS-CoV-2, is often facilitated through household contact. To better understand the transmission rate of COVID-19 among households and factors that affect viral clearance and seroconversion, a case-ascertained community-based prospective study was conducted between December 2020 and June 2021 on the urban population of the national capital region of India. The study collected nasopharyngeal swabs for SARS-CoV-2 RT-PCR on the 1st, 7th, 14th, and 28th day, and blood samples for antibody detection on the 1st, 14th, and 28th day from household contacts (HCs) of laboratory-confirmed COVID-19 cases. The study monitored the demographic data, symptoms, and outcomes of 417 participants, including 99 index cases and 318 contacts, for a period of 28 days. The results of the study showed that SARS-CoV-2 was easily spread within households, with a secondary infection rate of 44.3 %. In fact, almost 70 % of the contacts got infected within 1-2 days of identification of the index case, while 34 % remained asymptomatic. Sero-conversion was found in 35.6 % of the participants while 22.9 % did not produce antibodies after 28 days of infection. The study also revealed that females, spouses, older members, and primary care providers were at higher risk of getting infected in a home setting. However, approximately one-third of individuals in the younger age group managed to avoid infection. The study demonstrated that most infected individuals became RT-PCR negative within two weeks, although viral clearance was delayed in older patients and those with lower cycle threshold values in RT-PCR.

Phenotyping of lymphocyte subsets, Th-1/Th-2 cytokines and other parameters in high-risk contacts of SARS-CoV-2.

Background: The information on the pathophysiology of infection in high-risk contacts of SARS-CoV-2 is limited. Aims: The aim of the present study was to assess the various factors and their elucidation in the protection of SARS- CoV-2 infection in high-risk contacts. Settings and Design: Cross-sectional descriptive clinical study. Materials and Methods: A total of 136 subjects were recruited in the present study including 100 high-risk subjects and 36 control subjects. Out of 100 high-risk subjects, 44 subjects were found positive for SARS-CoV-2 RNA. Further, absolute blood counts of total T-cells (CD3+), T-helper cells (CD4+), T-cytotoxic cells (CD8+), B lymphocytes (CD19+) Natural Killer (NK) Cells (CD16+, CD56+), cytokines, and other parameters were measured in the samples of study subjects. Statistical Analysis Used: The continuous variables were analyzed by unpaired 't' test, analysis of variance and 'Tukey test' for multiple comparisons. Results: A significant reduction of total leukocyte counts and absolute lymphocyte count was found in the acute SARS-CoV-2 positive group as compared to control group (<0.05). Interestingly, IL-4 level was significantly elevated in SARS-CoV-2 negative high-risk subjects as compared to control and acute SARS-CoV-2 positive group (p < 0.05). A significant decrease of T-cytotoxic, B-cells, and NK cells were found in acute SARS-CoV-2 positive subjects as compared to control groups. Conclusion: The findings of this study may augment our knowledge about the pathogenesis of SARS-CoV-2 infection that could help in making future strategies to control its infection.

In Silico Guided Nanoformulation Strategy for Circumvention of Candida albicans Biofilm for Effective Therapy of Candidal Vulvovaginitis.

Candidal vulvovaginitis involving multispecies of Candida and epithelium-bound biofilm poses a drug-resistant pharmacotherapeutic challenge. The present study aims for a disease-specific predominant causative organism resolution for the development of a tailored vaginal drug delivery system. The proposed work fabricates a luliconazole-loaded nanostructured lipid carrier-based transvaginal gel for combating Candida albicans biofilm and disease amelioration. The interaction and binding affinity of luliconazole against the proteins of C. albicans and biofilm were assessed using in silico tools. A systematic QbD analysis was followed to prepare the proposed nanogel using a modified melt emulsification-ultrasonication-gelling method. The DoE optimization was logically implemented to ascertain the effect of independent process variables (excipients concentration; sonication time) on dependent formulation responses (particle size; polydispersity index; entrapment efficiency). The optimized formulation was characterized for final product suitability. The surface morphology and dimensions were spherical and ≤300 nm, respectively. The flow behavior of an optimized nanogel (semisolid) was non-Newtonian similar to marketed preparation. The texture pattern of a nanogel was firm, consistent, and cohesive. The release kinetic model followed was Higuchi (nanogel) with a % cumulative drug release of 83.97 ± 0.69% in 48 h. The % cumulative drug permeated across a goat vaginal membrane was found to be 53.148 ± 0.62% in 8 h. The skin-safety profile was examined using a vaginal irritation model (in vivo) and histological assessments. The drug and proposed formulation(s) were checked against the pathogenic strains of C. albicans (vaginal clinical isolates) and in vitro established biofilms. The visualization of biofilms was done under a fluorescence microscope revealing mature, inhibited, and eradicated biofilm structures.

Household transmission dynamics of COVID-19 among residents of Delhi, India: a prospective case-ascertained study.

Objective: The aim of this study was to observe the secondary infection rate and transmission dynamics of COVID-19 among household contacts, and their associations with various factors across four dimensions of interaction. Methods: This was a case-ascertained study among unvaccinated household contacts of a laboratory-confirmed COVID-19 case in New Delhi between December 2020 and July 2021. For this study, 99 index cases and their 316 household contacts were interviewed and sampled (blood and oro-nasal swab) on days 1, 7, 14, and 28. Results: The secondary infection rate among unvaccinated household contacts was 44.6% (95% confidence interval (CI) 39.1-50.1). The predictors of secondary infection among individual contact levels were: being female (odds ratio (OR) 2.13), increasing age (OR 1.01), symptoms at baseline (OR 3.39), and symptoms during follow-up (OR 3.18). Among index cases, age of the primary case (OR 1.03) and symptoms during follow-up (OR 6.29) were significantly associated with secondary infection. Among household-level and contact patterns, having more rooms (OR 4.44) and taking care of the index case (OR 2.02) were significantly associated with secondary infection. Conclusion: A high secondary infection rate highlights the need to adopt strict measures and advocate COVID-19-appropriate behaviors. A targeted approach for higher-risk household contacts would efficiently limit infections among susceptible contacts.

Genotypic characterization of vancomycin-resistant Enterococcus causing urinary tract infection in northern India.

Background & objectives: Infections caused by vancomycin-resistant Enterococci are difficult to treat given the limited therapeutic alternatives. Different gene clusters are known to confer vancomycin resistance. vanA and vanB genes are transferable and are clinically relevant. This cross-sectional study aimed to identify the vancomycin-resistant genotypes in the strains causing urinary tract infection and also to test the in vitro efficacy of linezolid and pristinamycin against the vancomycin-resistant isolates. Methods: Antimicrobial resistance profile of 118 enterococcal isolates was evaluated. Minimum inhibitory concentration of vancomycin, teicoplanin and high-level gentamicin (HLG) was determined by micro broth dilution. The vancomycin-resistant isolates were tested against linezolid and pristinamycin by micro-broth dilution and E strip method. The presence of vancomycin-resistant genes was detected by multiplex polymerase chain reaction and was sequenced and analyzed. Results: Most commonly isolated species were Enterococcus faecalis (76.9%) and Enterococcus faecium (16.9%). It was found that 43 per cent of the isolates were resistant to HLG and 16.9 per cent to vancomycin. Higher resistance was seen against fluoroquinolones, erythromycin, tetracycline and ß-lactam drugs. However, 5.08 per cent strains were resistant to tigecycline. All vancomycin-resistant strains were sensitive to pristinamycin and one was resistant to linezolid. vanA and vanB gene were found in 15 and five isolates, respectively. The gene sequences were submitted to NCBI gene bank and accession numbers were obtained. Interpretation & conclusions: The present study showed prevalence of vanA and vanB genes carrying Enterococcus in a tertiary care centre in north India. The emergence of resistance against drugs such as tigecycline and linezolid is a topic of concern as it will be a therapeutic challenge for physicians.

Efficacy of polyherbal formulations for prevention of COVID-19 infection in high-risk subjects: A randomized open-label controlled clinical trial.

COVID-19 is arguably the biggest health crisis the world has faced in the 21st century. Therefore, two of the polyherbal formulations, Infuza and Kulzam were assessed for the prevention of COVID-19 infection as a repurposed medication. Four hundred seven high-risk subjects were recruited in the present open-label randomized controlled clinical trial for eligibility. After assessment for eligibility, remaining 251 subjects were randomized to the test and control groups. Further, 52 high-risk subjects in Infuza, 51 in Kulzam, 51 in Infuza & Kulzam and 53 in control group completed the 14 days of intervention/assessment. The phenotyping of lymphocytes at baseline (0 day) and after 14 days of treatment was carried out by flow cytometry assays. A total of 15.09% high-risk subjects in control group turned positive as compared to only 7.69% in Infuza, 3.92% in Kulzam and 1.96% in Infuza & Kulzam groups. The rate of conversion to COVID-19 infection in Infuza & Kulzam group was minimal and statistically significant as compared to control group (p0.017). No significant changes in phenotype of lymphocytes (T, B, NK cells), absolute lymphocyte count and cytokine levels were found in study groups. However, there was a decreasing trend of hs-CRP level in high-risk subjects after intervention of polyherbal formulations for 14 days. The combination of Infuza and Kulzam may synergistically prevent COVID-19 infection in high-risk subjects of COVID-19.

High-level gentamicin resistance mediated by Aac(6')-Ie-aph(2")-Ia gene in Enterococcus species isolated from clinical samples in Northern India.

CONTEXT: Enterococci are known to cause life-threatening infections which are difficult to treat as the organism harbors innate resistance to many antibiotics and can amass resistance toward many others through plasmid-mediated genetic exchange. AIMS: The study evaluates the drug susceptibility profile of various Enterococcus species isolated from various patient specimens submitted for bacteriological analysis and check the incidence of aac(6') Ie-aph(2") Ia gene. SETTING AND DESIGN: This in vitro cross-sectional study was executed at bacteriology laboratory of a 470 bedded hospital in New Delhi. MATERIALS AND METHODS: Drug susceptibility testing was carried out on enterococcal isolates. High-level gentamicin-resistant (HLGR) isolates detected by micro broth dilution assay were then subjected to molecular detection of aac(6') Ie-aph(2") Ia gene. STATISTICAL ANALYSIS USED: The level of significance was established by Chi-square test. RESULTS: Among the 182 enterococcal stains detected, 76.9% were Enterococcus faecalis and 20.3% were Enterococcus faecium. 12.08% strains were vancomycin resistant. 39% expressed resistance toward high-level gentamicin (HLG) and this finding was significantly higher in E. faecium than E. faecalis. HLGR strains expressed a higher degree of resistance to other drugs in contrast to non-HLGR isolates. In 67 out of 71 HLGR isolates the bifunctional gene was detected. CONCLUSION: Considerable presence of HLG and vancomycin resistance in the clinical isolates is alarming and should be taken seriously. The study shows high dissemination of aac(6')-Ie-aph(2")-Ia gene among Enterococci isolated from the region.

Asymptomatic SARS-COV-2 carriage and sero-positivity in high risk contacts of COVID-19 cases'.

PURPOSE: Identifying asymptomatic SARS-COV-2 carriage is one of the crucial factors in controlling the COVID 19 pandemic. The relationship between the asymptomatic viral carriage and the rate of seroconversion needs better understanding. The present study was conducted to identify the asymptomatic COVID-19 infection and seropositivity in high-risk contacts in the southern district of Delhi, India. METHODS: Following the screening of 6961 subjects, a total of 407 asymptomatic high-risk subjects were selected. Demographic data, socioeconomic status, and history of COVID-19 related symptoms in the last 4 months were recorded. Blood samples and Nasopharyngeal/oropharyngeal swabs were collected for the detection of SARS-COV-2 RNA and anti-SARS-COV-2 antibodies. RESULTS: 55 asymptomatic high-risk subjects (13.5%) tested positive for SARS-COV-2 infection and among them, 70.9% remained asymptomatic throughout their course of infection. The seropositivity among the subjects was 28.9% (n â€‹= â€‹118) and was found significantly higher among lower-middle socioeconomic strata (p â€‹= â€‹0.01). The antibody levels were significantly higher (p â€‹= â€‹0.033) in individuals with a previous history of COVID-19 like symptoms as compared to the subjects, who had no such history. Asymptomatic healthcare workers showed a significantly increased rate of SARS-COV-2 infection (p â€‹= â€‹0.004) and seropositivity (p â€‹= â€‹0.005) as compared to the non-healthcare workers. Subjects, who were exposed to infection at their workplace (non-hospital setting) had the least RT-PCR positivity rate (p â€‹= â€‹0.03). CONCLUSIONS: A large proportion of SARS-COV-2 infection remains completely asymptomatic. The rate of asymptomatic carriage and seropositivity is significantly higher in healthcare workers as compared to the general population. The level of SARS-COV-2 antibodies is directly related to the appearance of symptoms. These observations may contribute to redefining COVID 19 screening, infection control, and professional health practice strategies.

TLCoV- An automated Covid-19 screening model using Transfer Learning from chest X-ray images.

The Coronavirus disease (Covid-19) has been declared a pandemic by World Health Organisation (WHO) and till date caused 585,727 numbers of deaths all over the world. The only way to minimize the number of death is to quarantine the patients tested Corona positive. The quick spread of this disease can be reduced by automatic screening to cover the lack of radiologists. Though the researchers already have done extremely well to design pioneering deep learning models for the screening of Covid-19, most of them results in low accuracy rate. In addition, over-fitting problem increases difficulties for those models to learn on existing Covid-19 datasets. In this paper, an automated Covid-19 screening model is designed to identify the patients suffering from this disease by using their chest X-ray images. The model classifies the images in three categories - Covid-19 positive, other pneumonia infection and no infection. Three learning schemes such as CNN, VGG-16 and ResNet-50 are separately used to learn the model. A standard Covid-19 radiography dataset from the repository of Kaggle is used to get the chest X-ray images. The performance of the model with all the three learning schemes has been evaluated and it shows VGG-16 performed better as compared to CNN and ResNet-50. The model with VGG-16 gives the accuracy of 97.67%, precision of 96.65%, recall of 96.54% and F1 score of 96.59%. The performance evaluation also shows that our model outperforms two existing models to screen the Covid-19.

Biofilm synthesis and other virulence factors in multidrug-resistant uropathogenic enterococci isolated in Northern India.

Purpose: Enterococci express high degree of resistance towards wide range of antibiotics. Production of biofilm and many virulence factors along with drug resistance makes it difficult to eradicate the infection from urinary tract. The present study detected the expression of such factors including biofilm production by multidrug-resistant (MDR) enterococci. Materials and Methods: Drug susceptibility of 103 uropathogenic enterococci was performed followed by estimation of minimum inhibitory concentration of high-level gentamicin and vancomycin by microbroth dilution method. Vancomycin-resistant genes were detected by multiplex polymerase chain reaction. Production of virulence factors such as haemagglutination, caseinase, lipase, gelatinase, haemolysin and ß-lactamase was detected by phenotypic methods in MDR strains. Biofilm production was detected by calcofluor-white fluorescence staining and semi-quantitative adherence assay. Results: 45% and 18.4% of the isolates were high-level gentamicin-resistant and vancomycin-resistant enterococci (VRE), respectively. vanA gene was detected in 14 and vanB gene in 5 strains. Biofilm, caseinase and gelatinase were the most expressed virulence factor. Expression of caseinase, gelatinase and lipase was significantly higher in Enterococcus faecalis (P < 0.05). Expression of haemagglutination, gelatinase and haemolysin among the vancomycin-resistant isolates was significantly higher (P < 0.05). Conclusion: VanA and vanB are the prevalent genotypes responsible for vancomycin resistance. The high prevalence of MDR enterococcal strains producing biofilm and virulence determinants raises concern. asa1, hyl, esp, gelE, cyl and other genes are known to express these factors and contribute to biofilm formation. Most uropathogenic enterococci expressed biofilm at moderate level and can be detected effectively by calcofluor-white staining. No correlation was noted between vancomycin resistance and biofilm production.

Synthesis, biological evaluation and molecular docking of some substituted pyrazolines and isoxazolines as potential antimicrobial agents.

A series of substituted pyrazolines (2a-e, 3a-h and 6a-c) and isoxazolines (4a-e) were synthesized and their structures were established on the basis of IR, (1)H NMR, (13)C NMR and mass spectra. All the synthesized compounds were tested against two bacterial and four fungal strains and found to exhibit moderate to potent antifungal activity. Compounds 2b, 4c, 4d and 6a-c exhibited significant activity against all tested fungal strains. MIC values of all the active compounds were comparable with standard drug fluconazole. The results of the in silico molecular docking study supported the antifungal activity of the synthesized compounds.

Isolation of Aeromonas salmonicida from Human Blood Sample: A Case Report.

Aeromonas salmonicida belonging to the genus Aeromonas, is a common pathogen that causes furunculosis and septicaemia in variety of fishes. It infects cold blooded vertebrates living at low temperatures mainly salmonid fish hence named salmonicida. Untill recently Aeromanas salmonicida is considered to be a fish pathogen. A. salmonicida is considered to be non-pathogenic for humans as it cannot grow at 37ºC. "However, In our laboratory culture plates and broths were incubated twice at 37ºC and each time same type of colonies were isolated which were identified as A. samonicida by Vitek 2 compact system bioMerieux, Inc. (Durham, N.C.)". By far no report has been received regarding its isolation from humans biological sample. Here we present the first report of A. salmonicida isolated from the human blood.

The incidence of nocardiosis at pulmonary and extra - pulmonary sites.

Nocardiosis is a rare but well-established opportunistic infection. We are presenting two cases of Nocardiosis diagnosed in the microbiology laboratory, one in an immuno-competent elderly patient and the other in a immunocompromised patient with AIDS. The first case was of pulmonary Nocardiosis which was caused by the Nocardia asteroides complex and concomitant infections with Staphylococcus aureus and Blastoschizomyces capitatus. In the second case, Nocardia brasiliensis was isolated from the pus which was extracted from an HIV positive patient, with lymphoadenopathy in the neck, at the upper right clavicular region. Interestingly, in both the cases, the primary identification Was done using 20% H2SO4 as decolourizer for ZN staining method.

Community Acquired Bacteremia by Sphingomonas paucimobilis: Two Rare Case Reports.

S.paucimobilis has a diverse nutritional substrate spectrum and found in both environmental and hospital settings. Sphingomonas paucimobilis is rarely isolated from clinical specimen. This low virulence organism since has been reported to cause a variety of diseases since 1979. It has been reported to be associated with both community acquired and nosocomial diseases including bacteremia, catheter related sepsis, diarrhoeal diseases, peritonitis, meningitis, cutaneous infections, endopthalmitis, visceral infections , urinary tract infections etc. We report two cases of community acquired primary bacteremia by Sphingomonas paucimobilis. One of the patients was 55-year-old female who had gallbladder carcinoma and the other was a 2-year-old healthy male who had no history of any underlying disease. Both got admission in hospital with complaints of pyrexia. Blood culture yielded S.paucimobilis which was found to be sensitive to quinolones, chloramphenicol, carbapenems, aminoglycosides and beta lactams except penicillin and amoxicillin.

Assessment of different tests to detect methicillin resistant Staphylococcus aureus.

The heterogeneous expression of methicillin resistance in Staphylococcus aureus affects the efficiency of tests available to detect it. Not all laboratories have access to accurate molecular tests used for this purpose. This study compares the performances of four phenotypic tests used to detect methicillin resistant S. aureus (MRSA) with the mecA gene polymerase chain reaction. Two hundred thirty-seven S. aureus isolates were isolated from different patients visiting Sir Sundar Lal Hospital, Banaras Hindu University, Varanasi, India and subjected to cefoxitin and oxacillin disc diffusion tests, oxacillin minimum inhibitory concentration (MIC) test, and oxacillin screen agar test. The tests showed the following sensitivities and specificities, respectively: cefoxitin disc diffusion (98.5% and 100%), oxacillin disc diffusion (77.3% and 84.6%), oxacillin MIC (89.4% and 87.2%), and oxacillin screen agar (87.9% and 94.9%). The cefoxitin disc diffusion test can be the best method for routine detection of MRSA when molecular techniques are not available. We recommend the Clinical Laboratory Standards Institute (CLSI) cut-off point for determining cefoxitin resistance be reexamined to see if it should be revised from < or = 19 mm to < or = 20 mm.

Methicillin resistant Staphylococcus aureus: prevalence and antibiogram in a tertiary care hospital in western Nepal.

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community infections. Its prevalence varies with country and with hospitals within a country. The current study estimates the prevalence of MRSA strains and investigates their antibiogram in western Nepal. METHODOLOGY: A total of 162 S. aureus strains were isolated from various clinical specimens, and antibiotic susceptibility tests were performed using disc diffusion, growth on oxacillin screen agar, and oxacillin minimum inhibitory concentration (MIC). RESULTS: One hundred and twelve (69.1%) strains were found to be MRSA, of which 37 (33.1%) were community acquired and 75 (66.9%) were hospital acquired. Of 112 MRSA strains, 45 (40.1%) were multi-drug resistant. All MRSA strains were found resistant to penicillin, and 91.9%, 87.4%, 77%, and 55.5% were resistant to amoxicillin, ampicillin, trimethoprim/sulfamethoxazole, and cephalexin, respectively. However, low resistance was observed with amikacin (19%), ciprofloxacin (26.5%), and norfloxacin (30.6%). All strains were sensitive to vancomycin. CONCLUSION: The reported rate of MRSA prevalence is alarming. Given the ability of MRSA to spread from person to person, it is necessary to adhere to rational use of antibiotics and to raise awareness among the concerned communities and tourists who visit this area.