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1.
Gut Pathog ; 16(1): 36, 2024 Jul 07.
Article in English | MEDLINE | ID: mdl-38972985

ABSTRACT

BACKGROUND: Enteropathogenic E. coli (EPEC) causes acute infantile diarrhea accounting for significant morbidity and mortality in developing countries. EPEC uses a type three secretion system to translocate more than twenty effectors into the host intestinal cells. At least four of these effectors, namely EspF, Map, EspG1/G2 and NleA, are reported to disrupt the intestinal tight junction barrier. We have reported earlier that the expression of EspF and Map in MDCK cells causes the depletion of the TJ membrane proteins and compromises the integrity of the intestinal barrier. In the present study, we have examined the role of the proline-rich repeats (PRRs) within the C-terminus of EspF in the depletion of the tight junction membrane proteins and identified key endocytosis markers that interact with EspF via these repeats. RESULTS: We generated mutant EspF proteins which lacked one or more proline-rich repeats (PRRs) from the N-terminus of EspF and examined the effect of their expression on the cellular localization of tight junction membrane proteins. In lysates derived from cells expressing the mutant EspF proteins, we found that the C-terminal PRRs of EspF are sufficient to cause the depletion of TJ membrane proteins. Pull-down assays revealed that the PRRs mediate interactions with the TJ adaptor proteins ZO-1 and ZO-2 as well as with the proteins involved in endocytosis such as caveolin-1, Rab5A and Rab11. CONCLUSIONS: Our study demonstrates the direct role of the proline-rich repeats of EspF in the depletion of the TJ membrane proteins and a possible involvement of the PRRs in the endocytosis of host proteins. New therapeutic strategies can target these PRR domains to prevent intestinal barrier dysfunction in EPEC infections.

2.
Pediatr Infect Dis J ; 43(2): e67-e70, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38758207

ABSTRACT

We evaluated whether the quantification of IgG to pneumococcal capsular polysaccharides is an accurate diagnostic test for pneumococcal infection in children with pneumonia in Nepal. Children with pneumococcal pneumonia did not have higher convalescent, or higher fold change, IgG to pneumococcal polysaccharides than children with other causes of pneumonia. Caution is needed in interpreting antibody responses in pneumococcal infections.


Subject(s)
Antibodies, Bacterial , Community-Acquired Infections , Immunoglobulin G , Pneumonia, Pneumococcal , Polysaccharides, Bacterial , Streptococcus pneumoniae , Humans , Antibodies, Bacterial/blood , Child, Preschool , Polysaccharides, Bacterial/immunology , Immunoglobulin G/blood , Infant , Streptococcus pneumoniae/immunology , Pneumonia, Pneumococcal/diagnosis , Pneumonia, Pneumococcal/immunology , Community-Acquired Infections/diagnosis , Community-Acquired Infections/immunology , Male , Female , Child , Nepal , Bacterial Capsules/immunology
3.
Vaccine ; 42(19): 4066-4071, 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-38789369

ABSTRACT

BACKGROUND: Carriage studies are an efficient means for assessing pneumococcal conjugate vaccine effect in settings where pneumococcal disease surveillance programmes are not well established. In this study the effect of 10-valent pneumococcal conjugate vaccine (PCV10) introduction on pneumococcal carriage and density among Nepalese children using a bacterial microarray and qPCR was examined. METHODS: PCV10 was introduced into the Nepalese infant immunisation schedule in August 2015. Nasopharyngeal swabs were collected from healthy Nepalese children in Kathmandu between April 2014 and December 2021. Samples were plated on blood agar, incubated overnight, and DNA extracted from plate sweeps. Pneumococcal serotyping was done using the Senti-SPv1.5 microarray (BUGS Bioscience, UK). DNA was extracted from swab media and qPCR performed for pneumococcal autolysin (lytA). RESULTS: A significant decline in prevalence of PCV10 serotypes was observed when comparing pre-PCV10 with post-PCV10 collection periods (36.5 %, 454/1244 vs 10.3 %, 243/2353, p < 0.0001). Multiple-serotype carriage was also observed to significantly decline when comparing pre-PCV10 with post-PCV10 periods (31.4 %, 390/1244 vs 22.2 %, 522/2353, p < 0.0001). Additionally, a significant decline in median pneumococcal density was observed when comparing pre-PCV10 with post-PCV10 periods (3.3 vs 3.25 log10 GE/ml, p = 0.0196). CONCLUSIONS: PCV10 introduction was associated with reduced, prevalence of all PCV10 serotypes, multiple serotype carriage, and pneumococcal carriage density.


Subject(s)
Carrier State , Pneumococcal Infections , Pneumococcal Vaccines , Serogroup , Streptococcus pneumoniae , Humans , Pneumococcal Vaccines/administration & dosage , Pneumococcal Vaccines/immunology , Nepal/epidemiology , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/isolation & purification , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/genetics , Carrier State/epidemiology , Carrier State/microbiology , Pneumococcal Infections/prevention & control , Pneumococcal Infections/epidemiology , Pneumococcal Infections/microbiology , Infant , Male , Female , Child, Preschool , Serotyping , Prevalence , Nasopharynx/microbiology
4.
Sensors (Basel) ; 22(12)2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35746302

ABSTRACT

The hybrid combination between underwater optical wireless communication (UOWC) and radio frequency (RF) is a vital demand for enabling communication through the air-water boundary. On the other hand, non-orthogonal multiple access (NOMA) is a key technology for enhancing system performance in terms of spectral efficiency. In this paper, we propose a downlink NOMA-based dual-hop hybrid RF-UOWC with decode and forward (DF) relaying. The UOWC channels are characterized by exponential-generalized Gamma (EGG) fading, while the RF channel is characterized by Rayleigh fading. Exact closed-form expressions of outage probabilities and approximated closed-form expressions of ergodic capacities are derived, for each NOMA individual user and the overall system as well, under the practical assumption of imperfect successive interference cancellation (SIC). These expressions are then verified via Monte-Carlo simulation for various underwater scenarios. To gain more insight into the system performance, we analyzed the asymptotic outage probabilities and the diversity order. Moreover, we formulated and solved a power allocation optimization problem to obtain an outage-optimal performance. For the sake of comparison and to highlight the achievable gain, the system performance is compared against a benchmark orthogonal multiple access (OMA)-based system.

5.
Pediatr Infect Dis J ; 41(3): 192-198, 2022 03 01.
Article in English | MEDLINE | ID: mdl-34955523

ABSTRACT

BACKGROUND: Invasive bacterial disease (IBD; including pneumonia, meningitis, sepsis) is a major cause of morbidity and mortality in children in low-income countries. METHODS: We analyzed data from a surveillance study of suspected community-acquired IBD in children <15 years of age in Kathmandu, Nepal, from 2005 to 2013 before introduction of pneumococcal conjugate vaccines (PCV). We detailed the serotype-specific distribution of invasive pneumococcal disease (IPD) and incorporated antigen and PCR testing of cerebrospinal fluid (CSF) from children with meningitis. RESULTS: Enhanced surveillance of IBD was undertaken during 2005-2006 and 2010-2013. During enhanced surveillance, a total of 7956 children were recruited of whom 7754 had blood or CSF culture results available for analysis, and 342 (4%) had a pathogen isolated. From 2007 to 2009, all 376 positive culture results were available, with 259 pathogens isolated (and 117 contaminants). Salmonella enterica serovar Typhi was the most prevalent pathogen isolated (167 cases, 28% of pathogens), followed by Streptococcus pneumoniae (98 cases, 16% pathogens). Approximately, 73% and 78% of pneumococcal serotypes were contained in 10-valent and 13-valent PCV, respectively. Most cases of invasive pneumococcal disease (IPD) were among children ≥5 years of age from 2008 onward. Antigen and PCR testing of CSF for pneumococci, Haemophilus influenzae type b and meningococci increased the number of these pathogens identified from 33 (culture) to 68 (culture/antigen/PCR testing). CONCLUSIONS: S. enterica serovar Typhi and S. pneumoniae accounted for 44% of pathogens isolated. Most pneumococcal isolates were of serotypes contained in PCVs. Antigen and PCR testing of CSF improves sensitivity for IBD pathogens.


Subject(s)
Bacterial Infections/epidemiology , Streptococcus pneumoniae , Antigens, Bacterial , Bacterial Infections/blood , Bacterial Infections/cerebrospinal fluid , Bacterial Infections/microbiology , Child, Preschool , Female , Haemophilus influenzae type b , Humans , Infant , Male , Meningitis, Pneumococcal/epidemiology , Microbial Sensitivity Tests , Neisseria meningitidis , Nepal/epidemiology , Pneumococcal Infections/blood , Pneumococcal Infections/cerebrospinal fluid , Pneumococcal Infections/epidemiology , Pneumococcal Vaccines , Polymerase Chain Reaction , Serogroup , Serotyping , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/isolation & purification , Vaccines, Conjugate
6.
Semin Cancer Biol ; 83: 570-583, 2022 08.
Article in English | MEDLINE | ID: mdl-33421620

ABSTRACT

The understanding of the relationship between epigenetic alterations, their effects on gene expression and the knowledge that these epigenetic alterations are reversible, have opened up new therapeutic pathways for treating various diseases, including cancer. This has led the research for a better understanding of the mechanism and pathways of carcinogenesis and provided the opportunity to develop the therapeutic approaches by targeting such pathways. Epi-drugs, DNA methyl transferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors are the best examples of epigenetic therapies with clinical applicability. Moreover, precise genome editing technologies such as CRISPR/Cas has proven their efficacy in epigenome editing, including the alteration of epigenetic markers, such as DNA methylation or histone modification. The main disadvantage with DNA gene editing technologies is off-target DNA sequence alteration, which is not an issue with epigenetic editing. It is known that cancer is linked with epigenetic alteration, and thus CRISPR/Cas system shows potential for cancer therapy via epigenome editing. This review outlines the epigenetic therapeutic approach for cancer therapy using CRISPR/Cas, from the basic understanding of cancer epigenetics to potential applications of CRISPR/Cas in treating cancer.


Subject(s)
CRISPR-Cas Systems , Neoplasms , CRISPR-Cas Systems/genetics , DNA Methylation , Epigenesis, Genetic , Epigenome/genetics , Epigenomics , Gene Editing , Humans , Neoplasms/genetics , Neoplasms/therapy
7.
Biomaterials ; 275: 120953, 2021 08.
Article in English | MEDLINE | ID: mdl-34218051

ABSTRACT

Designing grafted biodegradable polymers with tailored multi-functional properties is one of the most researched fields with extensive biomedical applications. Among many biodegradable polymers, polycarbonates have gained much attention due to their ease of synthesis, high drug loading, and excellent biocompatibility profiles. Among various monomers, 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) derived cyclic carbonate monomers have been extensively explored in terms of their synthesis as well as their polymerization. Since the late 90s, significant advancements have been made in the design of bis-MPA derived cyclic carbonate monomers as well as in their reaction schemes. Currently, bis-MPA derived polycarbonates have taken a form of an entire platform with a multitude of applications, the latest being in the field of nanotechnology, targeted drug, and nucleic acid delivery. The present review outlines an up to date developments that have taken place in the last two decades in the design, synthesis, and biomedical applications of bis-MPA derived cyclic carbonates and their (co)polymers.


Subject(s)
Pharmaceutical Preparations , Polymers , Carbonates , Polycarboxylate Cement , Propionates
8.
Pediatr Infect Dis J ; 40(10): 937-943, 2021 10 01.
Article in English | MEDLINE | ID: mdl-34292271

ABSTRACT

BACKGROUND: The pneumococcal conjugate vaccine has had a substantial impact on invasive pneumococcal disease. Previously, we compared immunity following vaccination with the 10-valent pneumococcal conjugate vaccine (PCV10) administered at 2 slightly different schedules: at 6 and 10 weeks of age, and at 6 and 14 weeks of age, both followed by a 9-month booster. In this study, we followed up those participants to evaluate the medium-term persistence of serotype-specific pneumococcal immunity at 2-3 years of age. METHOD: Children from the previous studies were contacted and after taking informed consent from their parents, blood samples and nasopharyngeal swabs were collected. Serotype-specific IgG antibody concentrations were determined by enzyme-linked immunosorbent assay, for the 10 vaccine serotypes, at a WHO pneumococcal serology reference laboratory. FINDINGS: Two hundred twenty of the 287 children who completed the primary study returned at 2-3 years of age to provide a blood sample and nasopharyngeal swab. The nasopharyngeal carriage rate of PCV10 serotypes in the 6 + 14 group was higher than the 6 + 10 group (13.4% vs. 1.9%). Nevertheless, the proportion of toddlers with serum pneumococcal serotype-specific IgG greater than or equal to 0.35 µg/mL was comparable for all PCV10 serotypes between the 6 + 10 week and 6 + 14 week groups. Similarly, the geometric mean concentrations of serum pneumococcal serotype-specific IgG levels were similar in the 2 groups for all serotypes, except for serotype 19F which was 32% lower in the 6 + 10 group than the 6 + 14 group. CONCLUSION: Immunization with PCV10 at 6 + 10 weeks or 6 + 14 weeks, with a booster at 9 months in each case, results in similar persistence of serotype-specific antibody at 2-3 years of age. Thus, protection from pneumococcal disease is expected to be similar when either schedule is used.


Subject(s)
Antibodies, Bacterial/blood , Immunization Schedule , Pneumococcal Vaccines/administration & dosage , Pneumococcal Vaccines/immunology , Serogroup , Vaccination/methods , Carrier State/microbiology , Child, Preschool , Cross-Sectional Studies , Follow-Up Studies , Humans , Immunoglobulin G/blood , Nasopharynx/microbiology , Nepal , Pneumococcal Infections/immunology , Pneumococcal Infections/prevention & control , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/immunology , Vaccines, Conjugate/immunology
9.
BMC Infect Dis ; 21(1): 546, 2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34107906

ABSTRACT

BACKGROUND: Sepsis is an overwhelming and life-threatening response to bacteria in bloodstream and a major cause of neonatal morbidity and mortality. Understanding the etiology and potential risk factors for neonatal sepsis is urgently required, particularly in low-income countries where burden of infection is high and its epidemiology is poorly understood. METHODS: A prospective observational cohort study was conducted between April 2016 and October 2017 in a level three NICU at a tertiary care hospital in Nepal to determine the bacterial etiology and potential risk factors for neonatal sepsis. RESULTS: Among 142 NICU admitted neonates, 15% (21/142) and 32% (46/142) developed blood culture-positive and -negative neonatal sepsis respectively. Klebsiella pneumoniae (34%, 15/44) and Enterobacter spp. (25%, 11/44) were the most common isolates. The antimicrobial resistance of isolates to ampicillin (100%, 43/43), cefotaxime (74%, 31/42) and ampicillin-sulbactam (55%, 21/38) were the highest. BlaTEM (53%, 18/34) and blaKPC (46%, 13/28) were the commonest ESBL and carbapenemase genes respectively. In univariate logistic regression, the odds of sepsis increased with each additional day of use of invasive procedures such as mechanical ventilation (OR 1.086, 95% CI 1.008-1.170), umbilical artery catheter (OR 1.375, 95% CI 1.049-1.803), intravenous cannula (OR 1.140, 95% CI 1.062-1.225); blood transfusion events (OR 3.084, 95% CI 1.407-6.760); NICU stay (OR 1.109, 95% CI 1.040-1.182) and failure to breast feed (OR 1.130, 95% CI 1.060-1.205). Sepsis odds also increased with leukopenia (OR 1.790, 95% CI 1.04-3.082), increase in C-reactive protein (OR 1.028, 95% CI 1.016-1.040) and decrease in platelets count (OR 0.992, 95% CI 0.989-0.994). In multivariate analysis, increase in IV cannula insertion days (OR 1.147, 95% CI 1.039-1.267) and CRP level (OR 1.028, 95% CI 1.008-1.049) increased the odds of sepsis. CONCLUSIONS: Our study indicated various nosocomial risk factors and underscored the need to improve local infection control measures so as to reduce the existing burden of sepsis. We have highlighted certain sepsis associated laboratory parameters along with identification of antimicrobial resistance genes, which can guide for early and better therapeutic management of sepsis. These findings could be extrapolated to other low-income settings within the region.


Subject(s)
Neonatal Sepsis/epidemiology , Neonatal Sepsis/microbiology , Cohort Studies , Humans , Infant, Newborn , Intensive Care Units, Neonatal , Nepal/epidemiology , Prospective Studies , Risk Factors , Tertiary Care Centers
10.
J Coll Physicians Surg Pak ; 29(12): S160-S162, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31779776

ABSTRACT

We report a case of a mature cystic teratoma of urinary bladder in a 17-year female, which is extremely rare. The patient presented with pain in suprapubic region for one year. On computerized tomography (CT) of abdomen and pelvis, a welldefined, enhancing heterogeneous soft tissue density lesion measuring 2.5x2.3x3 cm with mean density of 48 Hounsfield unit was found originating from the superior wall of the urinary bladder and projecting into the lumen. Cystoscopy showed a 2X2 cm growth containing concretions. Resection of the lesion was done with wide margin by transurethral resection of bladder tumor (TURBT). Histopathological examination showed fragments of skin, sebaceous glands, fat and muscle cells, confirming mature cystic teratoma.


Subject(s)
Cystectomy/methods , Cystoscopy/methods , Neoplasm Staging , Teratoma/diagnosis , Urinary Bladder Neoplasms/diagnosis , Adolescent , Biopsy , Female , Humans , Teratoma/surgery , Tomography, X-Ray Computed/methods , Urinary Bladder Neoplasms/surgery
11.
Lancet Infect Dis ; 19(2): 156-164, 2019 02.
Article in English | MEDLINE | ID: mdl-30635252

ABSTRACT

BACKGROUND: Nepalese infants receive ten-valent pneumococcal conjugate vaccine (PCV10) with a 1 month interval between priming doses for programmatic reasons. We aimed to investigate whether immune responses to PCV10 serotypes were non-inferior if the second priming dose of PCV10 was delivered at a 1 month interval as opposed to a 2 month interval. METHODS: We did an open-label, randomised, parallel group trial in healthy Nepalese infants aged 40-60 days at Patan Hospital, Kathmandu, Nepal. Children were eligible for inclusion if they were healthy, were born at more than or equal to 37 weeks' gestation, were residing in Kathmandu, and had not had any previous vaccinations other than BCG, and oral polio vaccine. Participants were randomly assigned (1:1) by means of a computer-generated list with randomly varying permuted block sizes accessed through a validated web-based interface, to receive PCV10 either at 6 weeks and 10 weeks of age (6 + 10 group) or at 6 weeks and 14 weeks of age (6 + 14 group), with both groups receiving a booster at 9 months of age. Laboratory staff, masked to study intervention, analysed serum samples for antibodies against PCV10 serotypes by ELISA. The primary outcome was to determine whether the 6 + 10 schedule was non-inferior to the 6 + 14 schedule at 9 months of age, on the basis of the proportion of infants with serotype-specific IgG greater than or equal to 0·35 µg/mL. Non-inferiority was established with a 10% margin, and the primary endpoint was measured in a modified intention-to-treat population, which included only participants who successfully had a blood sample collected. This trial is registered at ClinicalTrials.gov, number NCT02385513. FINDINGS: Between Aug 21, 2015, and April 4, 2016, 304 Nepalese children were randomly assigned to either the 6 + 10 group (n=152) or the 6 + 14 group (n=152). At 9 months of age, the 6 + 10 schedule was non-inferior for serotype 5 (79 [55·2%] of 143 vs 78 [53·4%] of 146, difference 1·82% [95% CI -9·6 to 13·25], p=0·021), serotype 9V (66 [46·1%] of 143 vs 55 [37·6%] of 146, difference 8·48% [-2·84 to 19·8], p=0·001), serotype 14 (110 [77·4%] of 142 vs 110 [74·8%] of 147, difference 2·63% [-7·27 to 12·54], p=0·006), and serotype 19F (135 [95%] of 142 vs 146 [100%] of 146, difference -4·92% [-9·86 to 0], p=0·022). At the same timepoint, non-inferiority was not shown for serotype 1 (36 [25·1%] of 143 vs 42 [28·5%] of 147, difference -3·39% [95% CI -13·56 to 6·77], p=0·102), serotype 4 (70 [48·9%] of 143 vs 87 [59·1%] of 147, difference -10·23% [-21·64 to 1·18], p=0·516), serotype 6B (96 [67·1%] of 143 vs 114 [77·5%] of 147, difference -10·41% [-20·65 to -0·18], p=0·532), serotype 7F (99 [69·2%] of 143 vs 109 [74·1%] of 147, difference -4·91% [-15·26 to 5·42], p=0·168), serotype 18C (89 [62·2%] of 143 vs 114 [77·5%] of 147, difference -15·31% [-25·78 to -4·83], p=0·840), and serotype 23F (37 [25·8%] of 143 vs 41 [27·8%] of 147, difference -2·01% [-12·19 to 8·16], p=0·062). After the booster dose, at 10 months of age, there were no significant differences in immunogenicity (proportion of children with antibody greater than or equal to 0.35 µg/mL) for any of the ten serotypes, when comparing the two schedules. Serious adverse events occurred in 32 participants, 11 (7%) of 152 in the 6 + 10 group and 21 (14%) of 152 in the 6  +  14 group. INTERPRETATION: The 6 week, 14 week, and 9 month schedule should be implemented where possible. However, post-booster responses, which are thought to drive herd immunity, were similar in the two schedules. Therefore, the 6 week, 10 week, and 9 month schedule is an alternative that can be used when logistically necessary, and is expected to provide herd protection. FUNDING: Gavi, the Vaccine Alliance.


Subject(s)
Immunization Schedule , Immunization, Secondary/methods , Pneumococcal Infections/epidemiology , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/therapeutic use , Streptococcus pneumoniae/immunology , Vaccines, Conjugate/therapeutic use , Antibodies, Bacterial/blood , Female , Humans , Immunity, Herd , Immunogenicity, Vaccine , Immunoglobulin G/blood , Infant , Male , Nepal/epidemiology , Pneumococcal Infections/microbiology , Pneumococcal Vaccines/immunology , Serogroup , Treatment Outcome , Vaccines, Conjugate/immunology
12.
Article in English | MEDLINE | ID: mdl-32039044

ABSTRACT

New diagnostic tests for the etiology of childhood pneumonia are needed. We evaluated the antibody-in-lymphocyte supernatant (ALS) assay to detect immunoglobulin (Ig) G secretion from ex vivo peripheral blood mononuclear cell (PBMC) culture, as a potential diagnostic test for pneumococcal pneumonia. We enrolled 348 children with pneumonia admitted to Patan Hospital, Kathmandu, Nepal between December 2015 and September 2016. PBMCs sampled from participants were incubated for 48 h before harvesting of cell culture supernatant (ALS). We used a fluorescence-based multiplexed immunoassay to measure the concentration of IgG in ALS against five conserved pneumococcal protein antigens. Of children with pneumonia, 68 had a confirmed etiological diagnosis: 12 children had pneumococcal pneumonia (defined as blood or pleural fluid culture-confirmed; or plasma CRP concentration ≥60 mg/l and nasopharyngeal carriage of serotype 1 pneumococci), and 56 children had non-pneumococcal pneumonia. Children with non-pneumococcal pneumonia had either a bacterial pathogen isolated from blood (six children); or C-reactive protein <60 mg/l, absence of radiographic consolidation and detection of a pathogenic virus by multiplex PCR (respiratory syncytial virus, influenza viruses, or parainfluenza viruses; 23 children). Concentrations of ALS IgG to all five pneumococcal proteins were significantly higher in children with pneumococcal pneumonia than in children with non-pneumococcal pneumonia. The concentration of IgG in ALS to the best-performing antigen discriminated between children with pneumococcal and non-pneumococcal pneumonia with a sensitivity of 1.0 (95% CI 0.73-1.0), specificity of 0.66 (95% CI 0.52-0.78) and area under the receiver-operating characteristic curve (AUROCC) 0.85 (95% CI 0.75-0.94). Children with pneumococcal pneumonia were older than children with non-pneumococcal pneumonia (median 5.6 and 2.0 years, respectively, p < 0.001). When the analysis was limited to children ≥2 years of age, assay of IgG ALS to pneumococcal proteins was unable to discriminate between children with pneumococcal pneumonia and non-pneumococcal pneumonia (AUROCC 0.67, 95% CI 0.47-0.88). This method detected spontaneous secretion of IgG to pneumococcal protein antigens from cultured PBMCs. However, when stratified by age group, assay of IgG in ALS to pneumococcal proteins showed limited utility as a test to discriminate between pneumococcal and non-pneumococcal pneumonia in children.


Subject(s)
Immunologic Tests/methods , Lymphocytes/immunology , Pneumonia, Pneumococcal/diagnosis , Pneumonia, Pneumococcal/immunology , Streptococcus pneumoniae/immunology , Adolescent , Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Bacterial Proteins/immunology , C-Reactive Protein/analysis , Child , Child, Preschool , Diagnostic Tests, Routine/methods , Female , Humans , Immunoglobulin G/blood , Infant , Leukocytes, Mononuclear/immunology , Male , Nepal , Prospective Studies , Sensitivity and Specificity , Streptococcus pneumoniae/isolation & purification
13.
PLoS Negl Trop Dis ; 12(4): e0006408, 2018 04.
Article in English | MEDLINE | ID: mdl-29684021

ABSTRACT

BACKGROUND: Children are substantially affected by enteric fever in most settings with a high burden of the disease, including Nepal. However pathogen population structure and transmission dynamics are poorly delineated in young children, the proposed target group for immunization programs. Here we present whole genome sequencing and antimicrobial susceptibility data on 198 S. Typhi and 66 S. Paratyphi A isolated from children aged 2 months to 15 years of age during blood culture surveillance at Patan Hospital, Nepal, 2008-2016. PRINCIPAL FINDINGS: S. Typhi was the dominant agent and comprised several distinct genotypes, dominated by 4.3.1 (H58). The heterogeneity of genotypes in children under five was reduced compared to data from 2005-2006, attributable to ongoing clonal expansion of H58. Most isolates (86%) were non-susceptible to fluoroquinolones, associated mainly with S. Typhi H58 lineage II and S. Paratyphi A harbouring mutations in the quinolone resistance-determining region (QRDR); non-susceptible strains from these groups accounted for 50% and 25% of all isolates. Multi-drug resistance (MDR) was rare (3.5% of S. Typhi, 0 S. Paratyphi A) and restricted to chromosomal insertions of resistance genes in H58 lineage I strains. Temporal analyses revealed a shift in dominance from H58 Lineage I to H58 Lineage II, with the latter being significantly more common after 2010. Comparison to global data sets showed the local S. Typhi and S. Paratyphi A strains had close genetic relatives in other South Asian countries, indicating regional strain circulation. Multiple imports from India of ciprofloxacin-resistant H58 lineage II strains were identified, but these were rare and showed no evidence of clonal replacement of local S. Typhi. SIGNIFICANCE: These data indicate that enteric fever in Nepal continues to be a major public health issue with ongoing inter- and intra-country transmission, and highlights the need for regional coordination of intervention strategies. The absence of a S. Paratyphi A vaccine is cause for concern, given its prevalence as a fluoroquinolone resistant enteric fever agent in this setting.


Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Bacterial , Salmonella typhi/immunology , Typhoid Fever/epidemiology , Typhoid-Paratyphoid Vaccines , Adolescent , Child , Child, Preschool , Ciprofloxacin/therapeutic use , Female , Fluoroquinolones/therapeutic use , Genotype , Humans , Infant , Male , Nepal/epidemiology , Salmonella typhi/genetics , Salmonella typhi/isolation & purification , Salmonella typhi/physiology , Typhoid Fever/microbiology , Typhoid Fever/prevention & control
14.
Sci Rep ; 8(1): 3719, 2018 02 27.
Article in English | MEDLINE | ID: mdl-29487356

ABSTRACT

Enteropathogenic E. coli infection is characterized by rapid onset of diarrhea but the underlying mechanisms are not well defined. EPEC targets the tight junctions which selectively regulate the permeability of charged and uncharged molecules. Cooperative actions of the EPEC effectors EspF and Map have been reported to mediate tight junction disruption. To analyze the individual contributions of EspF and Map, we generated in vitro models where EspF and Map, derived from the EPEC strain E2348/69, were constitutively expressed in epithelial cells. Here we report that tight junction disruption by EspF and Map is caused by the inhibition of the junctional recruitment of proteins during tight junction assembly. Constitutive expression of EspF and Map depleted the levels of tight junction proteins. EspF down-regulated the transcript levels of claudin-1, occludin and ZO-1, while Map down-regulated only claudin-1 transcripts. Both effectors also caused lysosomal degradation of existing tight junction proteins. We also identified a novel interaction of Map with non-muscle myosin II. Consistent with earlier studies, EspF was found to interact with ZO-1 while actin was the common interacting partner for both effectors. Our data provides evidence for the distinct roles of Map and EspF in tight junction disruption through non-synergistic functions.


Subject(s)
Enteropathogenic Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Tight Junctions/metabolism , Tight Junctions/microbiology , Carrier Proteins/genetics , Carrier Proteins/metabolism , Cell Line , Enteropathogenic Escherichia coli/genetics , Epithelial Cells/metabolism , Escherichia coli Infections/microbiology , Escherichia coli Proteins/genetics , Humans , Intestinal Mucosa/cytology , Intracellular Signaling Peptides and Proteins
16.
BMC Pharmacol Toxicol ; 18(1): 56, 2017 07 10.
Article in English | MEDLINE | ID: mdl-28693558

ABSTRACT

BACKGROUND: An estimated 2.7 of the 5.9 million deaths in children under 5 years of age occur in the neonatal period. Severe infections contribute to almost a quarter of these deaths. Mortality due to severe infections in developing country settings is substantial despite antibiotic therapy. Effective interventions that can be added to standard therapy for severe infections are required to reduce case fatality. METHODS/DESIGN: This is a double-blind randomized placebo-controlled parallel group superiority trial to investigate the effect of zinc administered orally as an adjunct to standard therapy to infants aged 3 days up to 2 months (59 days) hospitalized with clinical severe infection, that will be undertaken in seven hospitals in Delhi, India and Kathmandu, Nepal. In a 1:1 ratio, we will randomly assign young infants to receive 10 mg of elemental zinc or placebo orally in addition to the standard therapy for a total of 14 days. The primary outcomes hospital case fatality, which is death due to any cause and at any time after enrolment while hospitalized for the illness episode, and extended case fatality, which encompasses the period until 12 weeks after enrolment. DISCUSSION: A previous study showed a beneficial effect of zinc in reducing the risk of treatment failure, as well as a non-significant effect on case fatality. This study was not powered to detect an effect on case fatality, which this current study is. If the results are consistent with this earlier trial, we would have provided strong evidence for recommending zinc as an adjunct to standard therapy for clinical severe infection in young infants. TRIAL REGISTRATION: Universal Trial Number: U1111-1187-6479, Clinical Trials Registry - India: CTRI/2017/02/007966 : Registered on February 27, 2017.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Hospital Mortality , Zinc/therapeutic use , Anti-Bacterial Agents/adverse effects , Chemotherapy, Adjuvant , Double-Blind Method , Humans , Infant , Infant, Newborn , Treatment Outcome , Zinc/adverse effects
17.
PLoS One ; 12(6): e0179233, 2017.
Article in English | MEDLINE | ID: mdl-28604801

ABSTRACT

Young children are at greatest risk of exposure to lead and its effects. Although lead is one of the most widely used elements with known health hazard, there is little data on the blood lead level (BLL) of children in the Kathmandu Valley. Thus, this study aimed to assess factors associated with high BLL in children who were 6-36 months of age and resided in the Kathmandu Valley. In this hospital-based cross-sectional study 6-36 month-old children visiting the Paediatrics Outpatient Department of Tribhuvan University Teaching Hospital, Patan Hospital, and Siddhi Memorial Hospital were enrolled. All three hospitals are located in different areas inside the Kathmandu Valley. Written informed consent was obtained from the parents, and exposure data were collected using a structured questionnaire. Portable Anodic Stripping Voltammetry (ASV) was used to determine BLLs in children. Data were analyzed using SPSS version 16. Of 312 children enrolled in the study, 64.4% had BLLs ≥5µg/dl. A significant association was found between BLL and exposure to enamel paints in the household in the form of painting materials used in different parts of the house like walls, windows and doors (p = 0.001). Furthermore, multivariate analyses showed that BLLs were 4.5 times higher in children playing with dirt and dust (p = 0.006) and that children belonging to the community of lower caste/ethnicity groups had significantly higher BLLs compared to those from the upper caste groups (p = 0.02). Our study demonstrated that children living in households that have used enamel paints, children belonging to lower caste/ethnic groups, and children frequently playing with dirt and dust had significantly higher BLLs. The results of this study highlight the importance of policy decisions to limit environmental lead contamination, and to roll out awareness building measures designed to limit lead exposure and break the poverty cycle associated with chronic lead poisoning.


Subject(s)
Lead/blood , Public Health Surveillance , Child, Preschool , Cross-Sectional Studies , Environmental Exposure , Female , Humans , Infant , Lead Poisoning/blood , Lead Poisoning/epidemiology , Male , Nepal/epidemiology , Odds Ratio , Risk Factors
18.
Indian J Otolaryngol Head Neck Surg ; 66(4): 455-9, 2014 Dec.
Article in English | MEDLINE | ID: mdl-26396961

ABSTRACT

Auditory neuropathy (AN) describes patients with dysfunction of the auditory nerve in the presence of preserved cochlear outer hair-cell receptor functions in presence of normal otoacoustic emissions and/or cochlear microphonics. In individuals with auditory neuropathy speech are disproportionate to their hearing sensitivity and reported to be dependent on cortical evoked potentials. In individuals with AN, who have normal cortical potentials have better speech identification scores when compared to those with abnormal cortical potentials reflect relation between the cortical potentials and the speech identification scores. One group comparison research design was used for present study. The purpose of the study was to compare shift in latency of LLR peaks at different sensation level in subjects with auditory neuropathy and age matched normal individuals. 6 subjects (11 ears) diagnosed as having auditory neuropathy and 6 subjects (12 ears) with normal hearing Sensitivity participated for the study. Pure tone audiometry, immittance, reflexometry and otoacoustic emissions were administered. ABR was recorded for all the subjects at a repetition rate of 11.1 at an intensity of 90 dB nHL. LLR was carried out at different intensity levels for/da/speech stimulus at an intensity of 90 dB nHL. Latency of N1 and P2 of LLR was calculated at different sensation levels for both the groups. Descriptive analysis was carried out to find out the mean and standard deviation for latency of N1 and P2 for both, AN and normal hearing group. There was delay in latency of N1 and P2 for individuals with auditory neuropathy.

19.
BMC Infect Dis ; 11: 294, 2011 Oct 28.
Article in English | MEDLINE | ID: mdl-22035278

ABSTRACT

BACKGROUND: Acute encephalitis syndrome (AES) is commonly seen among hospitalized Nepali children. Japanese Encephalitis (JE) accounts for approximately one-quarter of cases. Although poor prognostic features for JE have been identified, and guide management, relatively little is reported on the remaining three-quarters of AES cases. METHODS: Children with AES (n = 225) were identified through admission records from two hospitals in Kathmandu between 2006 and 2008. Patients without available lumbar puncture results (n = 40) or with bacterial or plasmodium infection (n = 40) were analysed separately. The remaining AES patients with suspected viral aetiology were classified, based on positive IgM antibody in serum or cerebral spinal fluid, as JE (n = 42) or AES of unknown viral aetiology (n = 103); this latter group was sub-classified into Non-JE (n = 44) or JE status unknown (n = 59). Bad outcome was defined as death or neurological sequelae at discharge. RESULTS: AES patients of suspected viral aetiology more frequently had a bad outcome than those with bacterial or plasmodium infection (31% versus 13%; P = 0.039). JE patients more frequently had a bad outcome than those with AES of unknown viral aetiology (48% versus 24%; P = 0.01). Bad outcome was independently associated in both JE and suspected viral aetiology groups with a longer duration of fever pre-admission (P = 0.007; P = 0.002 respectively) and greater impairment of consciousness (P = 0.02; P < 0.001). A higher proportion of JE patients presented with a focal neurological deficit compared to patients of unknown viral aetiology (13/40 versus 11/103; P = 0.005). JE patients weighed less (P = 0.03) and exhibited a higher respiratory rate (P = 0.003) compared to Non-JE patients. CONCLUSIONS: Nepali children with AES of suspected viral aetiology or with JE frequently suffered a bad outcome. Despite no specific treatment, patients who experienced a shorter duration of fever before hospital admission more frequently recovered completely. Prompt referral may allow AES patients to receive potentially life-saving supportive management. Previous studies have indicated supportive management, such as fluid provision, is associated with better outcome in JE. The lower weight and higher respiratory rate among JE patients may reflect multiple clinical complications, including dehydration. The findings suggest a more systematic investigation of the influence of supportive management on outcome in AES is warranted.


Subject(s)
Encephalitis/complications , Encephalitis/pathology , Nervous System Diseases/epidemiology , Adolescent , Antibodies, Viral/blood , Antibodies, Viral/cerebrospinal fluid , Bacteria/isolation & purification , Child , Child, Preschool , Encephalitis/etiology , Encephalitis/mortality , Female , Hospitals , Humans , Immunoglobulin M/blood , Immunoglobulin M/cerebrospinal fluid , Infant , Male , Nepal , Nervous System Diseases/etiology , Plasmodium/isolation & purification , Prognosis , Retrospective Studies , Spinal Puncture , Survival Analysis , Treatment Outcome
20.
J Med Case Rep ; 2: 57, 2008 Feb 23.
Article in English | MEDLINE | ID: mdl-18294388

ABSTRACT

INTRODUCTION: Systemic hypersensitivity reactions to topical ophthalmic treatment occur rarely, but when they do they can be severe as highlighted by this case. CASE PRESENTATION: A post-operative cataract surgery patient developed a severe and generalised hypersensitivity reaction following topical treatment with Maxitrol (Dexamethasone and Neomycin) eye drops. The patient reported a previous allergic reaction to Neomycin. CONCLUSION: This case report emphasises the importance of a thorough drug and allergy history when patients are seen at pre-assessment or clerked in for surgery.

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