Browsing by Author "Arghya Das"

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Adaptations of carbapenem resistant Acinetobacter baumannii (CRAB) in the hospital environment causing sustained outbreak
(Microbiology Society, 2021) Swati Sharma; Arghya Das; Tuhina Banerjee; Hiranmay Barman; Ghanshyam Yadav; Ashok Kumar
Introduction. Carbapenem resistance in Acinetobacter baumannii (A. baumannii) is an emerging global threat. Gap statement. The adaptation strategies of A. baumannii for this emergence as a nosocomial pathogen has been less studied. Aim. This prospective study analysed a sustained outbreak of carbapenem resistant Acinetobacter baumannii (CRAB) in the intensive care unit (ICU) with reference to antimicrobial resistance and virulence in the colonizing and pathogenic isolates under carbapenem stress. Results. The CRAB isolates from initial and sustained outbreak were found harbouring multiple carbapenemase genes. These genes included blaOXA-23,blaIMP, blaVIM and blaNDM. From NICU environment three phenotypically carbapenem susceptible isolates were found carrying blaOXA-23, blaIMP, blaVIM genes. Prior imipenem therapy was one of the risk factors (P=0.0016). The outbreak was polyclonal. Under imipenem stress, outbreak isolates showed no loss of carbapenemase genes against stress free conditions (23.7±1.33 days). Biofilm formation increased with imipenem concentration, with outbreak isolates producing highest biomass. While the pathogens showed a slow growth rate on imipenem exposure, the colonisers grew rapidly (P <0.0001). Methods. Sustained outbreak of CRAB was identified in the ICU (July 2015 to December 2017). Risk factors for acquisition of CRAB was studied. A. baumannii isolates were also collected from the environments of ICU and neonatal ICU (NICU) and blood cultures of septic neonates. Isolates were characterized based on antimicrobial susceptibility, genetic profile, integrons carriage and clonality. Biofilm formation and growth kinetics were studied under varying carbapenem stress. Conclusion. Intense carbapenem exposure in the ICU facilitates persistence of CRAB by several adaptations causing sustained outbreaks. © 2021 The Authors.
Designing New Magic Bullets to Penetrate the Mycobacterial Shield: An Arduous Quest for Promising Therapeutic Candidates
(Mary Ann Liebert Inc., 2023) Anwita Mishra; Arghya Das; Tuhina Banerjee
Mycobacterium spp. intimidated mankind since time immemorial. The triumph over this organism was anticipated with the introduction of potent antimicrobials in the mid-20th century. However, the emergence of drug resistance in mycobacteria, Mycobacterium tuberculosis, in particular, caused great concern for the treatment. With the enemy growing stronger, there is an immediate need to equip the therapeutic arsenal with novel and potent chemotherapeutic agents. The task seems intricating as our understanding of the dynamic nature of the mycobacteria requires intense experimentation and research. Targeting the mycobacterial cell envelope appears promising, but its versatility allows it to escape the lethal effect of the molecules acting on it. The unique ability of hiding (inactivity during latency) also assists the bacterium to survive in a drug-rich environment. The drug delivery systems also require upgradation to allow better bioavailability and tolerance in patients. Although the resistance to the novel drugs is inevitable, our commitment to the research in this area will ensure the discovery of effective weapons against this formidable opponent. Copyright © 2023 Mary Ann Liebert, Inc.
Evaluation of Xpert MTB/RIF Assay for Diagnosis of Tuberculosis in Children
(Oxford University Press, 2019) Arghya Das; Shampa Anupurba; Om P. Mishra; Tuhina Banerjee; Rajneesh Tripathi
Introduction Childhood tuberculosis (TB) is now a global priority. With the advent of Xpert MTB/RIF, more TB cases in children are being reported. This study was undertaken to evaluate the performance of Xpert in diagnosis of pulmonary and extra-pulmonary TB in children. Methods Specimens from 171 suspected TB cases in children aged <15 years were tested with Xpert, culture and smear microscopy in the Department of Microbiology, Institute of Medical Sciences, India. Results The specimens included 106 gastric aspirates, 51 cerebrospinal fluids, 8 induced sputum and 6 lymph node aspirates. Xpert detected Mycobacterium tuberculosis in 19 cases (14 pulmonary and 5 extra-pulmonary), 7 of which were rifampicin-resistant. Sensitivity, specificity, positive predictive value and negative predictive value of Xpert compared with culture were 88.89, 98.04, 84.21 and 98.68%, respectively. The sensitivity was 100% in children aged 1-5 years and 6-10 years and in gastric aspirates. Conclusion Xpert is an efficient diagnostic tool in childhood tuberculosis. © 2018 The Author(s).
Hidden burden of chikungunya in North India; A prospective study in a tertiary care centre
(Elsevier Ltd, 2018) Anju Dinkar; Jitendra Singh; Pradyot Prakash; Arghya Das; Gopal Nath
Background: Arboviral diseases, such as chikungunya, dengue and now zika represent a public health problem, especially in tropical countries. Epidemiology of chikungunya and dengue is well known, including its social and climatic factors associated, but only few data and reports of chikungunya are available from North India. The clinical differentiation of chikungunya from dengue is no doubt challenging since both diseases can share clinical signs and symptoms leading to potential misdiagnosis of chikungunya in areas where dengue is endemic. The aim of this study was to know the seroprevalence, seasonal trends, clinical presentations of chikungunya and its co-infection with dengue virus. Methods: This was a prospective study conducted in Varanasi, from January to December 2016. All serum samples were tested for both chikungunya and dengue IgM antibodies by MAC ELISA test. Results: Total of 186 samples, out of which 108 (58%) samples were total seropositive, 23 (12.37%) samples positive for chikungunya IgM antibodies, 57 (30.65%) samples positive for dengue and 28 (15.05%) samples positive for both chikungunya and dengue. The most affected age group was 20-30 years and males were more affected than females. A seasonal peak for chikungunya and its co-infection with dengue were seen in November. Conclusion: In India, the seroprevalence of chikungunya is increasing. India is a rapidly developing country where adequate sanitation is required. More aggressive intervention and vigilance by health authorities is needed to decrease vector born diseases. © 2017 The Authors
Implementation of infection prevention and control practices in an upcoming COVID-19 hospital in India: An opportunity not missed
(Public Library of Science, 2022) Arghya Das; Rahul Garg; E. Sampath Kumar; Dharanidhar Singh; Bisweswar Ojha; H. Larikyrpang Kharchandy; Bhairav Kumar Pathak; Pushkar Srikrishnan; Ravindra Singh; Immanuel Joshua; Sanket Nandekar; J. Vinothini; Reenu Reghu; Nikitha Pedapanga; Tuhina Banerjee; Kamal Kumar Yadav
Infection prevention and control (IPC) program is obligatory for delivering quality services in any healthcare setup. Lack of administrative support and resource-constraints (under-staffing, inadequate funds) were primary barriers to successful implementation of IPC practices in majority of the hospitals in the developing countries. The Coronavirus Disease 2019 (COVID-19) brought a unique opportunity to improve the IPC program in these hospitals. A PDSA (Plan—Do—Study- Act) model was adopted for this study in a tertiary care hospital which was converted into a dedicated COVID-19 treatment facility in Varanasi, India. The initial focus was to identify the deficiencies in existing IPC practices and perceive the opportunities for improvement. Repeated IPC training (induction and reinforce) was conducted for the healthcare personnel (HCP) and practices were monitored by direct observation and closed-circuit television. Cleaning audits were performed by visual inspection, review of the checklists and qualitative assessment of the viewpoints of the HCP was carried out by the feedbacks received at the end of the training sessions. A total of 2552 HCP and 548 medical students were trained in IPC through multiple offline/onsite sessions over a period of 15 months during the ongoing pandemic. Although the overall compliance to surface disinfection and cleaning increased from 50% to >80% with repeated training, compliance decreased whenever newly recruited HCP were posted. Fear psychosis in the pandemic was the greatest facilitator for adopting the IPC practices. Continuous wearing of personal protective equipment for long duration, dissatisfaction with the duty rosters as well as continuous posting in high-risk areas were the major obstacles to the implementation of IPC norms. Recognising the role of an infection control team, repeated training, monitoring and improvisation of the existing resources are keys for successful implementation of IPC practices in hospitals during the COVID-19 pandemic. © 2022 Das et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In vitro susceptibility of dermatophytes to oral antifungal drugs and amphotericin B in Uttar Pradesh, India
(Wolters Kluwer Medknow Publications, 2019) Satyendra Kumar Singh; Dheeraj Kumar Patwa; Ragini Tilak; Arghya Das; Tej Bali Singh
Background: Dermatophytosis is a major public health problem in our country. Although resistance to conventional oral and topical antifungal agents is being increasingly encountered, the sensitivity pattern of dermatophytes has not been systematically analysed. Aims: We aimed to determine the sensitivity pattern of dermatophyte isolates to amphotericin B and six oral antifungal drugs. Materials and Methods: Patients with dermatophytosis attending the outpatient department of dermatology were enrolled in the study. Samples were collected for mycological examination and in vitro antifungal sensitivity testing was done by broth microdilution as per the Clinical and Laboratory Standard Institute M38-A standards. Results: A total of 804 patients were enrolled. Specimens from 185 patients (23%) were both KOH and culture positive, and 44 of these isolates (41 Trichophyton mentagrophytes and 3 Trichophyton rubrum) were subjected to sensitivity testing. Minimum inhibitory concentrations (MIC) of itraconazole, ketoconazole, voriconazole and amphotericin B were comparable. The median MIC to fluconazole was higher than the other tested drugs. Dermatophytes were most susceptible to ketoconazole and voriconazole, followed by itraconazole, amphotericin B, fluconazole and griseofulvin. A high incidence of resistance was found to terbinafine and the difference was statistically significant in comparison to fluconazole, itraconazole, voriconazole, ketoconazole (P = 0.001) and griseofulvin (P = 0.003). The strains were more sensitive to amphotericin B as compared to griseofulvin (P = 0.02) and terbinafine (P < 0.001). Limitations: This was a hospital-based study and may not reflect the true pattern in the community. Only a few of the isolates were selected for study. The clinical response of patients, whose isolates were studied for in vitro sensitivity of the antifungals, was not studied. Conclusions: The sensitivity pattern of dermatophytes to various antifungals including amphotericin B, ketoconazole, voriconazole and itraconazole were determined. The studied isolates were least susceptible to terbinafine. © 2019 Indian Journal of Dermatology, Venereology and Leprology.
Predominance of ancylostoma duodenale species among hookworm infected patients from a tertiary care hospital in Varanasi, India
(Indian Society for Malaria and Communicable Diseases, 2016) Arghya Das; Tuhina Banerjee
[No abstract available]
Reservoir of Carbapenem-Resistant Acinetobacter baumannii in the Hospital Environment and Colonization Pressure: A Surveillance-Based Study in Indian Intensive Care Unit
(Mary Ann Liebert Inc., 2022) Swati Sharma; Arghya Das; Rahul Garg; Sangita Pramanik; Pooja Marndi; Ravindra Singh; Tuhina Banerjee; Ghanshyam Yadav; Ashok Kumar
The endemicity of Acinetobacter baumannii in intensive care units (ICUs) is a serious concern. We studied the reservoirs of A. baumannii in the ICU and their effects on colonization pressure and transmission. A prospective surveillance (6 months) was conducted. Screening culture (rectal and axillary) swabs were collected within 48 hours admission and in 120 hours. Surveillance cultures from patients' surroundings, health care workers (HCWs), and hospital sewage were collected. A. baumannii was identified by phenotypic and genotypic methods. Carbapenem resistance and insertion sequence element were detected. Typing was done by repetitive extragenic palindromic-polymerase chain reaction and multilocus sequence typing. Colonization pressure was calculated and compared with environment colonizers. Of the 87 patients, 21.83% (19) were colonized with A. baumannii, 73.68% (14/19) were imported, and 26.31% (5/19) acquired carriers. Axilla was the commonest site. From the environment (15), bed rails 33.33% (5/15) and suction tubes 26.66% (4/15) were the common sites. HCWs showed 7.5% (3/40) carriage. Carbapenem resistance with blaOXA-51, blaOXA-23, and ISAba1 were 91.89% (34/37). Strong correlation between colonization pressures and environmental colonizers was seen (r2 = 0.719, p = 0.032). Carbapenem and polymyxin B were (p ≤ 0.05) significant exposures. Sequence type 623 was the predominant cluster with isolates from carriers, HCWs, and environment. Colonization pressure of carbapenem-resistant A. baumannii depends on their presence in the hospital. Hands of HCWs were an important vehicle for transmission. Infection control measure should consider reducing the environmental reservoir. © Copyright 2022, Mary Ann Liebert, Inc., publishers 2022.
Standardization and classification of in vitro biofilm formation by clinical isolates of Staphylococcus aureus
(Medknow Publications, 2017) Ashish Singh; Pradyot Prakash; Arvind Achra; Gyan Singh; Arghya Das; Rakesh Singh
Background: Staphylococcus aureus is Gram-positive bacterium commonly associated with nosocomial infections. The development of biofilm exhibiting drug resistance especially in foreign body associated infections has enabled the bacterium to draw considerable attention. However, till date, consensus guidelines for in vitro biofilm quantitation and categorization criterion for the bacterial isolates based on biofilm-forming capacity are lacking. Therefore, it was intended to standardize in vitro biofilm formation by clinical isolates of S. aureus and then to classify them on the basis of their biofilm-forming capacity. Materials and Methods: A study was conducted for biofilm quantitation by tissue culture plate (TCP) assay employing 61 strains of S. aureus isolated from clinical samples during May 2015- December 2015 wherein several factors influencing the biofilm formation were optimized. Therefore, it was intended to propose a biofilm classification criteria based on the standard deviation multiples of the control differentiating them into non, low, medium, and high biofilm formers. Results: Brain-heart infusion broth was found to be more effective in biofilm formation compared to trypticase soy broth. Heat fixation was more effective than chemical fixation. Although, individually, glucose, sucrose, and sodium chloride (NaCl) had no significant effect on biofilm formation, a statistically significant increase in absorbance was observed after using the supplement mix consisting of 222.2 mM glucose, 116.9 mM sucrose, and 1000 mM NaCl (P = 0.037). Conclusions: The present study puts forth a standardized in vitro TCP assay for biofilm biomass quantitation and categorization criteria for clinical isolates of S. aureus based on their biofilm-forming capacity. The proposed in vitro technique may be further evaluated for its usefulness in the management of persistent infections caused by the bacterium. © 2017 Journal of Global Infectious Diseases | Published by Wolters Kluwer - Medknow.
Strictly adhering to infection control practices is the key to safe surgical procedures amidst the COVID-19 crisis
(Journal of Pure and Applied Microbiology, 2020) Rahul Garg; Arghya Das; Tuhina Banerjee
Currently, the world is facing a challenge to curb the outbreak of the highly contagious COviD-19, which has significantly impacted many lives and is affecting the practice of healthcare professionals as well. During this containment phase, an influx of COVID-19 patients requiring surgical interventions is expected. To combat the situation, every health care staff must implement and adhere to various infection prevention and control measures. In this article, we have addressed the importance of basic infection prevention and control practices required for handling COVID-19 cases, especially, those requiring acute surgical care. On one hand, certain non-emergency procedures need to be delayed, on the other hand, all surgeries during this period need to be proactively performed with appropriate infection control precautions regardless of the COVID-19 status of the patient. Prudent decisions and a conservative approach while making the best choices regarding surgeries will not only ensure personal protection but will also preserve important resources, manpower, hospital beds, and equipment for repurposing during this urgent crisis. © The Author(s) 2020.
Susceptibility of Nitrofurantoin and Fosfomycin against Outpatient Urinary Isolates of Multidrug-Resistant Enterococci over a Period of 10 Years from India
(Mary Ann Liebert Inc., 2020) Arghya Das; Tuhina Banerjee; Shampa Anupurba
With the increasing emergence of drug resistance in enterococci, there have been very limited data on the efficacy of orally available nitrofurantoin and fosfomycin on enterococci causing urinary tract infections (UTIs), particularly for multidrug-resistant (MDR) strains. This study aimed to determine the in vitro effectiveness of these two drugs against the MDR enterococci. A total of 514 phenotypically and genotypically confirmed isolates of enterococci (239, 46.5% Enterococcus faecalis and 275, 53.5% Enterococcus faecium) showed E. faecalis as significantly more resistant (p < 0.05) to ciprofloxacin and high strength gentamicin. Vancomycin resistance was seen in 37 (7.2%) isolates. Of these, 114 (22.18%) isolates (51, 44.73% E. faecalis and 63, 55.26% E. faecium) were MDR. Nitrofurantoin minimum inhibitory concentrations (MICs) for the MDR enterococci varied from 1 to 128 μg/mL (MIC50 8 μg/mL, MIC90 64 μg/mL for E. faecalis), while fosfomycin MICs for the MDR E. faecalis, including vancomycin resistant enterococci (VRE) were in susceptible range (≤64 μg/mL, MIC50 8 μg/mL, MIC90 16 μg/mL). An efficacy ratio of ≥8 for nitrofurantoin was observed in the 39 (76.5%) MDR E. faecalis and 44 (69.8%) MDR E. faecium isolates as against the 50 (98%) E. faecalis isolates for fosfomycin. Although nitrofurantoin has been widely prescribed for the treatment of UTIs for the past several years, it was still found to be active in vitro against the urinary isolates of MDR enterococci, including VRE. As for fosfomycin, it holds robust potential to be used against the urinary MDR enterococci and VRE (E. faecalis). © 2020, Mary Ann Liebert, Inc., publishers 2020.
The microflora of chronic diabetic foot ulcers based on culture and molecular examination: A descriptive study
(HMP Communications, 2019) Tuhina Banerjee; Arghya Das; Aradhana Singh; Rajan Bansal; Somprakas Basu
Infection of chronic diabetic foot ulcers (DFUs) is a major concern in patients with diabetes mellitus. PURPOSE: This prospective, descriptive study was conducted to evaluate clinical wound parameters and to determine the aerobic and anaerobic microflora of DFUs with 1 or more clinical signs of infection using culture and molecular methods. METHODS: Patients with a DFU and clinical signs of infection receiving care at a tertiary care hospital in Varanasi, India, were consecutively enrolled. Patient and wound characteristics were assessed, and the cultures obtained were analyzed quantitatively to detect aerobes/ facultative anaerobes and by polymerase chain reaction for common anaerobes. If no organisms were found using these methods, sequence analysis of bacterial 16S ribosomal RNA (16SrRNA) was used. Clinical, demographic, and microbial flora variables were compared using the chi-squared test, and predictors of culture results were ascertained using multiple logistic regressions. RESULTS: Forty (40) patients participated. Of those, 30 (75%) had positive culture results with a total of 64 isolates (2.13 isolates/ulcer). The ratio of aerobes to anaerobes was 1.24:1 (35/29); Peptococcus spp was the most frequent isolate (15, 23.4%). Proteobacteria and Firmicutes were detected by 16SrRNA in 6 of the 10 samples (60%), their presence not detected by other methods. Ulcer size <11.84 cm2 (OR: 4.71; 95% CI: 0.93-23.68) and ulcer on the dorsum of the foot (OR: 0.92; 95% CI: 0.05-16.42) were significantly associated (P <.05) with monomicrobial microflora. CONCLUSION: Gram-negative aerobic/facultative anaerobes predominated in the 30 DFUs that exhibited clinical signs of infection. Further experimental studies are required to understand the diverse microorganisms present in DFUs and their potential role in wound infections. © 2019 HMP Communications. All rights reserved.