Papers by Upendra Thapa Shrestha
Research Square (Research Square), May 30, 2024
medRxiv (Cold Spring Harbor Laboratory), Jun 29, 2023
Infectious diseases, 2021
Infection stems from complex interactions between a host, pathogen, and the environment. 1 Among ... more Infection stems from complex interactions between a host, pathogen, and the environment. 1 Among various infections, cardiac infections are life threatening and can affect all parts of the heart including its valves, endocardium, myocardium, and pericardium. 2 Nosocomial infections are the main cause of morbidity and mortality among the patients undergoing cardiac surgery. 3 Major causes of nosocomial infections in patients undergoing cardiac surgery are the presence of major surgical wounds and frequent use of invasive monitoring devices, which affect the normal host defense mechanisms. 4 The most common pathogens involved in cardiac infections are S. aureus, viridians streptococci, coagulase negative staphylococci, and gram-negative bacilli. 5,6 Sternal infections are caused by coagulase-negative staphylococci (CONS). 7 The other predominant aerobic Gram-positive bacteria in cardiovascular infections is S. aureus. 8,9 S. aureus is the most common pathogen in both community and hospital-associated infections. 10 After major heart surgery, S. aureus is the main cause of surgical site infection (SSI) with the patient's endogenous microbiota as the principal source. 11 MRSA is a special strain of the S. aureus that has developed antibiotic resistance, first to penicillin since 1948s, and later to methicillin and related anti staphylococcal drugs (such as flucloxacillin, nafcillin, and oxacillin). MRSA are resistant to penicillins, cephalosporins, monobactams, and carbapenems, cephems, and β-lactams and β-lactamase inhibitor
Animals, Nov 7, 2020
The poultry industry is one of the top agribusinesses in Nepal. However, despite the government's... more The poultry industry is one of the top agribusinesses in Nepal. However, despite the government's restriction on the use of antibiotics as growth promotors in animals, the overuse and misuse of antibiotics can be seen all over the country. Such inappropriate use of antibiotics has led to the rise of antibiotic resistance among treatment options for both human and animal pathogens. Several findings suggest the failure of colistin, a polymyxin E antibiotic (once regarded as the last resort drug), in the treatment of human bacterial infections is due to the emergence and spread of the plasmid-mediated colistin resistance gene (mcr-1) among Gram-negative bacterial pathogens. The emergence and rapid transfer of resistant strains in poultry farms are associated with unwanted loss of livestock, economic burden and spread of drug-resistance to other animals, humans and the environment, as well. In this study, we characterized the mcr-1 gene from infected chicken livers, where prevalence was found to be alarmingly high. This study identifies the result of regulatory failures. Therefore, this report provides valuable reference to the policy makers so that a more effective policy can be formulated and implemented to curb the spread of drug-resistant pathogens.
BMC Pediatrics
Background Acute respiratory infections (ARIs) are one of the most common causes of mortality and... more Background Acute respiratory infections (ARIs) are one of the most common causes of mortality and morbidity worldwide. Every year millions of children suffer from viral respiratory tract infections (RTIs) ranging from mild to severe illnesses. Human Metapneumovirus (HMPV) is among the most frequent viruses responsible for RTIs. However, HMPV infections and their severity among children have not been explored yet in Nepal. Purpose Therefore, the study was focused on HMPV infections and other potential viral etiologies or co-infections using multiplex PCR among children attending Kanti Children’s Hospital and assessed the clinical characteristics of the infections as well as found the co-infections. A hospital-based cross-sectional study was designed and a convenience sampling method was used to enroll children of less than 15 years with flu-like symptoms from both outpatients and inpatients departments over three months of the study period. Results HMPV infection (13.3%) was the most...
Infectious Disease Reports, Apr 21, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Microbiology Insights
Purpose: Methicillin-resistant Staphylococcus aureus, a common bacterial pathogen causes various ... more Purpose: Methicillin-resistant Staphylococcus aureus, a common bacterial pathogen causes various infections. The acquisition of various antimicrobial-resistant genes in S. aureus has led to the transformation of this bacterium into a superbug. Vancomycin resistance among MRSA isolates is an emerging threat in empirical therapy of various infections. The study was hence aimed to find out the susceptibility status of S. aureus isolates toward vancomycin and detect mecA, vanA, and vanB genes among the isolates. Methods: A total of 1245 clinical samples from the participants attending a tertiary care hospital in Kathmandu were processed. S. aureus isolated from the samples were subjected to antibiotic susceptibility patterns using the modified Kirby-Bauer disk diffusion method. Agar dilution method was used to determine the minimum inhibitory concentration of vancomycin. The antibiotic-resistant genes such as mecA, vanA, and vanB among S. aureus isolates were screened by a conventional ...
Additional file 4. Characteristics of focus group participants.
Additional file 3. Comparison of number of cases imported and total number of cases in 2016 repor... more Additional file 3. Comparison of number of cases imported and total number of cases in 2016 reported through case-based surveillance and the World Malaria Report (WMR).
Diseases
Background: Antimicrobial resistance (AMR) among Gram-negative pathogens, predominantly ESBL-prod... more Background: Antimicrobial resistance (AMR) among Gram-negative pathogens, predominantly ESBL-producing clinical isolates, are increasing worldwide. The main aim of this study was to determine the prevalence of ESBL-producing clinical isolates, their antibiogram, and the frequency of ESBL genes (blaTEM and blaCTX-M) in the clinical samples from patients. Methods: A total of 1065 clinical specimens from patients suspected of heart infections were collected between February and August 2019. Bacterial isolates were identified on colony morphology and biochemical properties. Thus, obtained clinical isolates were screened for antimicrobial susceptibility testing (AST) using modified Kirby–Bauer disk diffusion method, while ESBL producers were identified by using a combination disk diffusion method. ESBL positive isolates were further assessed using conventional polymerase chain reaction (PCR) to detect the ESBL genes blaTEM and blaCTX-M. Results: Out of 1065 clinical specimens, 17.8% (190...
ABSTRACTBackgroundAcute Respiratory Tract Infection (ARI) is one of the most common causes of mor... more ABSTRACTBackgroundAcute Respiratory Tract Infection (ARI) is one of the most common causes of mortality and morbidity worldwide. Every year millions of children suffer from viral Respiratory Tract Infections (RTIs) ranging from mild to severe illnesses. Human Metapneumovirus (HMPV) is among the most frequent viruses responsible for RTIs. However, HMPV infections and their severity among children have not been explored yet in Nepal. Therefore, the study aimed to determine the incidence of HMPV among children attending Kanti Children’s Hospital and assess the clinical characteristics of the infections as well as find out the co-infections.MethodsA hospital-based cross-sectional study was carried out from September 2018 to April 2019. A total of 105 throat swabs were collected from children clinically suspected of ARIs. The collected samples were tested for the presence of HMPV RNA by Multiplex Real-time PCR (RT-PCR) assay.ResultsThe incidence of HMPV in children in Kanti Children’s Ho...
Scientific Reports, 2021
Nepal suffers from high burden of antimicrobial resistance (AMR) due to inappropriate use of anti... more Nepal suffers from high burden of antimicrobial resistance (AMR) due to inappropriate use of antibiotics. The main objective of this study was to explore knowledge, attitude and practices of antibiotics uses among patients, healthcare workers, laboratories, drug sellers and farmers in eight districts of Nepal. A cross-sectional survey was conducted between April and July 2017. A total of 516 individuals participated in a face-to-face interview that included clinicians, private drug dispensers, patients, laboratories, public health centers/hospitals and, livestock and poultry farmers. Out of 516 respondents, 62.8% (324/516) were patients, 16.9% (87/516) were clinicians, 6.4% (33/516) were private drug dispensers. A significant proportion of patients (42.9%; 139/324) thought that fever could be treated with antibiotics. Majority (79%; 256/324) of the patients purchased antibiotics over the counter. The knowledge of antibiotics used among patients increased proportionately with the lev...
Microbiology Research, 2021
Klebsiella spp. are associated with several nosocomial and opportunistic infections. Increasing a... more Klebsiella spp. are associated with several nosocomial and opportunistic infections. Increasing antimicrobial resistance of Klebsiella species is aggravated by a number of intrinsic and extrinsic factors. The main aim of this study is to determine antimicrobial resistance due to production of β-lactamase enzymes, extended spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL) and AmpC and Klebsiella pneumoniae carbapenemase (KPC) and biofilm formation in Klebsiella isolates. A total of 2197 non-duplicate specimens of urine, sputum and pus were obtained from the National Public Health Laboratory (NPHL), Kathmandu, Nepal, between February and August 2019. Klebsiella species were isolated, identified and screened for antimicrobial susceptibility testing with the disk diffusion method. Phenotypic detection of ESBL, MBL, KPC and AmpC production was observed and biofilm production was detected by the microtiter plate method. Out of a total of 2197 clinical specimens, bacterial growt...
Tribhuvan University Journal of Microbiology
Objectives: This study was aimed to evaluate antibiotic resistance pattern and biofilm formation ... more Objectives: This study was aimed to evaluate antibiotic resistance pattern and biofilm formation in K. pneumoniae strains isolated from different clinical specimens and to study on association of drug resistance pattern with biofilm formation. Methods: A total of 944 clinical samples from patients attending Sahid Gangalal National Heart Center were processed from September 2019 to March 2020 to identify possible bacterial pathogens following standard microbiological procedures. K. pneumonaie isolates were further subjected to antibiotic susceptibility testing using modified Kirby Bauer disc diffusion technique. Biofilm formation was evaluated by tissue culture plate technique. Results: Of the total 944 samples, 15.47% (146) samples showed bacterial growth, among which 23.97% (35) were K. pneumoniae. Out of 35 K. pneumoniae isolates, 45.71% (16) were multidrug-resistant and 42.86% (15) were extensively drug-resistant. Sixty percent (21) of K. pneumoniae feebly produced biofilm. Signi...
ABSTRACTBackgroundWith extensive use of antimicrobial agents in poultry production to prevent and... more ABSTRACTBackgroundWith extensive use of antimicrobial agents in poultry production to prevent and treat diseases and as growth promoters, there has been an increase in antibiotic residue in the poultry meat and eggs. Quinolones are one of the highly prioritized, critically important drugs, whose residue in poultry can cause transmission of resistant zoonotic pathogens to humans. This study was conducted to assess the qualitative and quantitative residue of the quinolone in meat and eggs supplied to Kathmandu Valley, Nepal.MethodsA standard questionnaire was used to identify the trend of antibiotic application in the poultry industry. Epicollect+ android application was used for the survey. A total of 120 meat samples and 120 egg samples were collected from the specified five sectors. Enzyme Linked Immuno Sorbant Assay was employed to screen antimicrobial residues in the samples. Only the samples with antimicrobial residues above maximum residual limit value were quantified with High...
Tribhuvan University Journal of Microbiology
Objectives: To determine the prevalence of Gram-negative bacteria in lower respiratory tract infe... more Objectives: To determine the prevalence of Gram-negative bacteria in lower respiratory tract infections and study the biofilm producing Pseudomonas aeruginosa. Methods: This study was conducted at B & B Hospital Pvt. Ltd., Lalitpur, Nepal from February to September 2018. The samples were collected from the patients (n=420) with signs and symptoms suggestive of LRTIs. The isolated organisms were identified and antimicrobial sensitivity was performed. Among all the isolates, P. aeruginosa isolates were subjected for biofilm detection by microtitre plate method. Results: Out of 420 specimens, 90 (21.6%) were culture positive. Klebsiella pneumoniae (42.9%) was found to be the predominant organism with higher rate of resistance to antibiotics. A total of 25 isolates of P. aeruginosa were isolated among which 15 (60%) were biofilm producers. Biofilm-producing isolates of P. aeruginosa were found more resistant to the tested antibiotics. Conclusion: Gram-negative bacteria were found to be ...
Clinical Microbiology: Open Access, 2014
Introduction: Enteric fever continues to be a major health problem in under developed countries i... more Introduction: Enteric fever continues to be a major health problem in under developed countries including south Asian nations. In this study, we evaluate the prevalence and susceptibility pattern of Salmonella enteric (Serotype typhi, Paratyphi A and Paratyphi B). Methods: Blood samples were obtained from 3210 patients, suspected with enteric fever. The sample was processed on BACTEC 9050 and isolates obtained from subculture were serotyped and antibiotic susceptibility testing was carried out using disk diffusion (Kirby-Bauer). Result: Out of 3120 samples 370 isolates of S. enterica were isolated. The prevalence of Salmonella enterica was 11.8 % where 78.4% of these isolates were S. enteric serotype Typhi, 20.8% were S. enteric serotype Paratyphi A and0.8% were S. enteric serotype Paratyphi B. The isolates demonstrated poor susceptibility to oral antibiotics including Nalidixic acid, Ciprofloxacin, Ofloxacin, Azithromycin ,Amoxycillin, Tetracycline, Ceftriaxoneand Trimethoprim-sulfamethoxazole whereas all of the isolates of S. enterica demonstrated 100% susceptibility to Chloramphenicol. Conclusion: There was grater prevalence of Salmonella enterica serotype typhi isolates resistant to fluoroquinolones (Nalidixic acid, Ofloxacin and Ciprofloxacin). However Chloramphenicol was sensitive to all isolates. This study suggests Chloramphenicol as a drug of choice for enteric fever and further monitoring of efficacy of older and newer antibiotics are desirable.
Tribhuvan University Journal of Microbiology
Objectives: The study was aimed to identify potential bacterial pathogens from the panipuri sampl... more Objectives: The study was aimed to identify potential bacterial pathogens from the panipuri samples collected from different vendors of Bhaktapur district and determine their antibiogram patterns. Methods: Altogether 120 (40 puri, 40 stuffing and 40 pani) samples of panipuri were collected from different vendors of Bhaktapur district in a cold chain and were transported to the microbiology laboratory. Puri and stuffing were then pre-enriched, enriched and cultured while pani samples were processed using the MPN method. All the isolates were identified following standard microbiological procedure and subjected to antibiotic susceptibility testing following CLSI guidelines. Results: The result revealed contamination of 77.5% stuffing, 67.5% puri and 52.5% pani samples with pathogenic bacteria. Among bacterial pathogens, the highest number was Staphylococcus aureus followed by Escherichia coli and Salmonella spp. 100% of S. aureus were found to be resistant to ampicillin and novobiocin...
Tribhuvan University Journal of Microbiology, 2018
Objectives: This study aimed to identify the microbiological profile of various catheter tips, an... more Objectives: This study aimed to identify the microbiological profile of various catheter tips, and multidrug resistance pattern of extended spectrum β-lactamase (ESBL) producing E. coli and Klebsiella spp. isolates. Methods: A descriptive analysis of 263 catheter tip specimens processed for culture and antimicrobial susceptibility testing was carried out in B&B Hospital, Lalitpur. Five different types of catheter tips were analyzed for microbiological growth and antimicrobial susceptibility testing. Results: Among catheter tips, the highest percentage of microbial growth was observed in tracheostomy tip. Monomicrobial growth was recorded in 82.9% catheter tips and polymicrobial growth was observed in 17.1% tip samples. Of 180 isolates, gram negative rods (76.6%) followed by yeast (19.4%) and gram-positive cocci (3.9%) were isolated. Gram negative Acinetobacter spp. (25%) and Pseudomonas spp. (23.3%) and gram-positive Enterococcus spp. (2.2%) were the most frequently isolated bacteri...
BMC Microbiology, 2022
Background The management of enteric fever through antibiotics is difficult these days due to the... more Background The management of enteric fever through antibiotics is difficult these days due to the emerging resistance of Salmonella to various antimicrobial agents. The development of antimicrobial resistance is associated with multiple factors including mutations in the specific genes. To know the current status of mutation-mediated fluoroquinolone-resistance among Salmonella enterica serovars; Typhi, Paratyphi A, B and C, this study was focused on detecting gyrA ser83 mutation by restriction digestion analysis of gyrA gene using HinfI endonuclease. Results A total of 948 blood samples were processed for isolation of Salmonella spp. and 3.4% of them were found to be positive for Salmonella growth. Out of the 32 Salmonella isolates, 2.2% were S. Typhi and 1.2% were S. Paratyphi A. More interestingly, we observed less than 5% of isolates were resistant to first-line drugs including chloramphenicol, cotrimoxazole and ampicillin. More than 80% of isolates were resistant to fluoroquinol...
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Papers by Upendra Thapa Shrestha