CSNK2 suppresses autophagy by activating FLN-NHL-containing TRIM proteins

Macroautophagy/autophagy is a tightly regulated cellular process integral to homeostasis and innate immunity. As such, dysregulation of autophagy is associated with cancer, neurodegenerative disorders, and infectious diseases. While numerous factors that promote autophagy have been characterized, the key mechanisms that prevent excessive autophagy are less well understood. Here, we identify CSNK2/CK2 (casein kinase 2) as a negative regulator of autophagy. Pharmacological inhibition of CSNK2 activity or siRNA-mediated depletion of CSNK2 increased basal autophagic flux in cell lines and primary human lung cells. Vice versa, ectopic expression of CSNK2 reduced autophagic flux. Mechanistically, CSNK2 interacted with the FLN (filamin)-NHL domain-containing tripartite motif (TRIM) family members TRIM2, TRIM3 and TRIM71. Our data show that recruitment of CSNK2 to the C-terminal NHL domain of TRIM3 lead to its robust phosphorylation at serine 661 by CSNK2. A phosphorylation-defective mutant of TRIM3 was unable to reduce autophagosome numbers indicating that phosphorylation by CSNK2 is required for TRIM-mediated autophagy inhibition. All three TRIMs facilitated inactivation of the ULK1-BECN1 autophagy initiation complex by facilitating ULK1 serine 757 phosphorylation. Inhibition of CSNK2 promoted autophagy upon influenza A virus (IAV) and measles virus (MeV) infection. In line with this, targeting of CSNK2 or depletion of TRIM2, TRIM3 or TRIM71 enhanced autophagy-dependent restriction of IAV, MeV and human immunodeficiency virus 1 (HIV-1). Thus, our results identify the CSNK2-TRIM2, -TRIM3, -TRIM71 axis as a key regulatory pathway that limits autophagy. Targeting this axis may allow for therapeutic induction of autophagy against viral infections and in diseases associated with dysregulated autophagy.

Acetylation of the NS3 helicase by KAT5γ is essential for flavivirus replication

Direct targeting of essential viral enzymes such as proteases, polymerases, and helicases has long been the major focus of antiviral drug design. Although successful for some viral enzymes, targeting viral helicases is notoriously difficult to achieve, demanding alternative strategies. Here, we show that the NS3 helicase of Zika virus (ZIKV) undergoes acetylation in its RNA-binding tunnel. Regulation of the acetylated state of K389 in ZIKV NS3 modulates RNA binding and unwinding and is required for efficient viral replication. NS3 acetylation is mediated by a specific isoform of the host acetyltransferase KAT5 (KAT5γ), which translocates from the nucleus to viral replication complexes upon infection. NS3 acetylation by KAT5γ and its proviral role are also conserved in West Nile virus (WNV), dengue virus (DENV), and yellow fever virus (YFV). Our study provides molecular insight into how a cellular acetyltransferase regulates viral helicase functions, unveiling a previously unknown target for antiviral drug development.

Co-Circulation of Dengue Virus Serotypes 1, 2, and 3 during the 2022 Dengue Outbreak in Nepal: A Cross-Sectional Study

The largest dengue outbreak in the history of Nepal occurred in 2022, with a significant number of casualties. It affected all 77 districts, with the nation's capital, Kathmandu (altitude 1300 m), being the hardest hit. However, the molecular epidemiology of this outbreak, including the dengue virus (DENV) serotype(s) responsible for this epidemic, remain unknown. Here, we report the epidemic trends, clinico-laboratory features, and virus serotypes and their viral load profiles that are associated with this outbreak in Nepal. Dengue-suspected febrile patients were investigated by routine laboratory, serological, and molecular tools, including a real-time quantitative polymerase chain reaction (qRT-PCR). Of the 538 dengue-suspected patients enrolled, 401 (74.5%) were diagnosed with dengue. Among these dengue cases, 129 (32.2%) patients who required hospital admission had significant associations with myalgia, rash, diarrhea, retro-orbital pain, bleeding, and abdominal pain. DENV-1, -2, and -3 were identified during the 2022 epidemic, with a predominance of DENV-1 (57.1%) and DENV-3 (32.1%), exhibiting a new serotype addition. We found that multiple serotypes circulated in 2022, with a higher frequency of hospitalizations, more severe dengue, and more deaths than in the past. Therefore, precise mapping of dengue and other related infections through integrated disease surveillance, evaluation of the dynamics of population-level immunity and virus evolution should be the urgent plans of action for evidence-based policy-making for dengue control and prevention in the country.

Antibody-Dependent Enhancement Activity of a Plant-Made Vaccine against West Nile Virus

West Nile virus (WNV) causes annual outbreaks globally and is the leading cause of mosquito-borne disease in Unite States. In the absence of licensed therapeutics, there is an urgent need to develop effective and safe human vaccines against WNV. One of the major safety concerns for WNV vaccine development is the risk of increasing infection by related flaviviruses in vaccinated subjects via antibody-dependent enhancement of infection (ADE). Herein, we report the development of a plant-based vaccine candidate that provides protective immunity against a lethal WNV challenge mice, while minimizes the risk of ADE for infection by Zika (ZIKV) and dengue (DENV) virus. Specifically, a plant-produced virus-like particle (VLP) that displays the WNV Envelope protein domain III (wDIII) elicited both high neutralizing antibody titers and antigen-specific cellular immune responses in mice. Passive transfer of serum from VLP-vaccinated mice protected recipient mice from a lethal challenge of WNV infection. Notably, VLP-induced antibodies did not enhance the infection of Fc gamma receptor-expressing K562 cells by ZIKV or DENV through ADE. Thus, a plant-made wDIII-displaying VLP presents a promising WNV vaccine candidate that induces protective immunity and minimizes the concern of inducing ADE-prone antibodies to predispose vaccinees to severe infection by DENV or ZIKV.

GTF3A mutations predispose to herpes simplex encephalitis by disrupting biogenesis of the host-derived RIG-I ligand RNA5SP141

Herpes simplex virus 1 (HSV-1) infects several billion people worldwide and can cause life-threatening herpes simplex encephalitis (HSE) in some patients. Monogenic defects in components of the type I interferon system have been identified in patients with HSE, emphasizing the role of inborn errors of immunity underlying HSE pathogenesis. Here, we identify compound heterozygous loss-of-function mutations in the gene GTF3A encoding for transcription factor IIIA (TFIIIA), a component of the RNA polymerase III complex, in a patient with common variable immunodeficiency and HSE. Patient fibroblasts and GTF3A gene-edited cells displayed impaired HSV-1-induced innate immune responses and enhanced HSV-1 replication. Chromatin immunoprecipitation sequencing analysis identified the 5S ribosomal RNA pseudogene 141 (RNA5SP141), an endogenous ligand of the RNA sensor RIG-I, as a transcriptional target of TFIIIA. GTF3A mutant cells exhibited diminished RNA5SP141 expression and abrogated RIG-I activation upon HSV-1 infection. Our work unveils a crucial role for TFIIIA in transcriptional regulation of a cellular RIG-I agonist and shows that GTF3A genetic defects lead to impaired cell-intrinsic anti-HSV-1 responses and can predispose to HSE.

Actin cytoskeleton remodeling primes RIG-I-like receptor activation

The current dogma of RNA-mediated innate immunity is that sensing of immunostimulatory RNA ligands is sufficient for the activation of intracellular sensors and induction of interferon (IFN) responses. Here, we report that actin cytoskeleton disturbance primes RIG-I-like receptor (RLR) activation. Actin cytoskeleton rearrangement induced by virus infection or commonly used reagents to intracellularly deliver RNA triggers the relocalization of PPP1R12C, a regulatory subunit of the protein phosphatase-1 (PP1), from filamentous actin to cytoplasmic RLRs. This allows dephosphorylation-mediated RLR priming and, together with the RNA agonist, induces effective RLR downstream signaling. Genetic ablation of PPP1R12C impairs antiviral responses and enhances susceptibility to infection with several RNA viruses including SARS-CoV-2, influenza virus, picornavirus, and vesicular stomatitis virus. Our work identifies actin cytoskeleton disturbance as a priming signal for RLR-mediated innate immunity, which may open avenues for antiviral or adjuvant design.

Herpesvirus-mediated stabilization of ICP0 expression neutralizes restriction by TRIM23

Herpes simplex virus (HSV) infection relies on immediate early proteins that initiate viral replication. Among them, ICP0 is known, for many years, to facilitate the onset of viral gene expression and reactivation from latency. However, how ICP0 itself is regulated remains elusive. Through genetic analyses, we identify that the viral γ134.5 protein, an HSV virulence factor, interacts with and prevents ICP0 from proteasomal degradation. Furthermore, we show that the host E3 ligase TRIM23, recently shown to restrict the replication of HSV-1 (and certain other viruses) by inducing autophagy, triggers the proteasomal degradation of ICP0 via K11- and K48-linked ubiquitination. Functional analyses reveal that the γ134.5 protein binds to and inactivates TRIM23 through blockade of K27-linked TRIM23 autoubiquitination. Deletion of γ134.5 or ICP0 in a recombinant HSV-1 impairs viral replication, whereas ablation of TRIM23 markedly rescues viral growth. Herein, we show that TRIM23, apart from its role in autophagy-mediated HSV-1 restriction, down-regulates ICP0, whereas viral γ134.5 functions to disable TRIM23. Together, these results demonstrate that posttranslational regulation of ICP0 by virus and host factors determines the outcome of HSV-1 infection.

Novel Coronavirus Disease (COVID-19): Social Distancing, Isolation and Quarantine are Key Success Factors of Nepal's Public Health Practices or Something Else?

Novel Coronavirus Disease (COVID-19) is an infectious disease similar form of pneumonia/ SARS-CoV-2- impacting deadly globally. The main objective of this article is to analyze the studies and gather of the current information aimed at COVID-19 and analyze the situation of Nepal. We summarized the published articles from the web pages, Journals, Google search engine. It is declared as a public health emergency. However, why COVID-19 does not register in developing counties (Nepal) rather than China, Europe and North America it is unknown. Nepal has lower experiences of the COVID-19 where only 49 death cases registered and total cases 19,237 cases throughout the country (till 08/1/2020). Nepalese health services need to maintain up than today and follow lockdown, isolation, social distance and an advance screening test kit around the country.

Interleukin-17A Facilitates Chikungunya Virus Infection by Inhibiting IFN-α2 Expression

Interferons (IFNs) are the key components of innate immunity and are crucial for host defense against viral infections. Here, we report a novel role of interleukin-17A (IL-17A) in inhibiting IFN-α2 expression thus promoting chikungunya virus (CHIKV) infection. CHIKV infected IL-17A deficient (Il17a^-/- ) mice expressed a higher level of IFN-α2 and developed diminished viremia and milder footpad swelling in comparison to wild-type (WT) control mice, which was also recapitulated in IL-17A receptor-deficient (Il17ra^-/- ) mice. Interestingly, IL-17A selectively blocked IFN-α2 production during CHIKV, but not West Nile virus (WNV) or Zika virus (ZIKV), infections. Recombinant IL-17A treatment inhibited CHIKV-induced IFN-α2 expression and enhanced CHIKV replication in both human and mouse cells. We further found that IL-17A inhibited IFN-α2 production by modulating the expression of Interferon Regulatory Factor-5 (IRF-5), IRF-7, IFN-stimulated gene 49 (ISG-49), and Mx1 expression during CHIKV infection. Neutralization of IL-17A in vitro leads to the increase of the expression of these antiviral molecules and decrease of CHIKV replication. Collectively, these results suggest a novel function of IL-17A in inhibiting IFN-α2-mediated antiviral responses during CHIKV infection, which may have broad implications in viral infections and other inflammatory diseases.

ISG15-dependent Activation of the RNA Sensor MDA5 and its Antagonism by the SARS-CoV-2 papain-like protease

Activation of the RIG-I-like receptors, RIG-I and MDA5, establishes an antiviral state by upregulating interferon (IFN)-stimulated genes (ISGs). Among these is ISG15 whose mechanistic roles in innate immunity still remain enigmatic. Here we report that ISGylation is essential for antiviral IFN responses mediated by the viral RNA sensor MDA5. ISG15 conjugation to the caspase activation and recruitment domains of MDA5 promotes the formation of higher-order assemblies of MDA5 and thereby triggers activation of innate immunity against a range of viruses including coronaviruses, flaviviruses and picornaviruses. The ISG15-dependent activation of MDA5 is antagonized through direct de-ISGylation mediated by the papain-like protease (PLpro) of SARS-CoV-2, a recently emerged coronavirus that causes the COVID-19 pandemic. Our work demonstrates a crucial role for ISG15 in the MDA5-mediated antiviral response, and also identifies a novel immune evasion mechanism of SARS-CoV-2, which may be targeted for the development of new antivirals and vaccines to combat COVID-19.

In vitro and in vivo efficacy of anti-chikungunya virus monoclonal antibodies produced in wild-type and glycoengineered Nicotiana benthamiana plants

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus, and its infection can cause long-term debilitating arthritis in humans. Currently, there are no licensed vaccines or therapeutics for human use to combat CHIKV infections. In this study, we explored the feasibility of using an anti-CHIKV monoclonal antibody (mAb) produced in wild-type (WT) and glycoengineered (∆XFT) Nicotiana benthamiana plants in treating CHIKV infection in a mouse model. CHIKV mAb was efficiently expressed and assembled in plant leaves and enriched to homogeneity by a simple purification scheme. While mAb produced in ∆XFT carried a single N-glycan species at the Fc domain, namely GnGn structures, WT produced mAb exhibited a mixture of N-glycans including the typical plant GnGnXF3 glycans, accompanied by incompletely processed and oligomannosidic structures. Both WT and ∆XFT plant-produced mAbs demonstrated potent in vitro neutralization activity against CHIKV. Notably, both mAb glycoforms showed in vivo efficacy in a mouse model, with a slight increased efficacy by the ∆XFT-produced mAbs. This is the first report of the efficacy of plant-produced mAbs against CHIKV, which demonstrates the ability of using plants as an effective platform for production of functionally active CHIKV mAbs and implies optimization of in vivo activity by controlling Fc glycosylation.

Zika Virus NS3 Mimics a Cellular 14-3-3-Binding Motif to Antagonize RIG-I- and MDA5-Mediated Innate Immunity

14-3-3 protein family members facilitate the translocation of RIG-I-like receptors (RLRs) to organelles that mediate downstream RLR signaling, leading to interferon production. 14-3-3ϵ promotes the cytosolic-to-mitochondrial translocation of RIG-I, while 14-3-3η facilitates MDA5 translocation to mitochondria. We show that the NS3 protein of Zika virus (ZIKV) antagonizes antiviral gene induction by RIG-I and MDA5 by binding to and sequestering the scaffold proteins 14-3-3ϵ and 14-3-3η. 14-3-3-binding is mediated by a negatively charged RLDP motif in NS3 that is conserved in ZIKV strains of African and Asian lineages and is similar to the one found in dengue and West Nile viruses. ZIKV NS3 is sufficient to inhibit the RLR-14-3-3ϵ/η interaction and to suppress antiviral signaling. Mutational perturbation of 14-3-3ϵ/η binding in a recombinant ZIKV leads to enhanced innate immune responses and impaired growth kinetics. Our study provides molecular understanding of immune evasion functions of ZIKV, which may guide vaccine and anti-flaviviral therapy development.

Tuberculosis in Nepal: Situation, Challenges and Ways Forward

Introduction: Globally, tuberculosis is a major public health problem. Moreover, the emergence of drug resistant forms of TB has threatened TB prevention and treatment efforts. Despite the long history of tuberculosis prevention efforts, tuberculosis still ranks among the top ten causes of deaths in Nepal. Furthermore, Nepal being land locked with two high TB burden countries i.e. India and China, it has added difficulties to National Tuberculosis program. Hence this study aims to review the situation of National Tuberculosis Program in Nepal and explore the possible challenges and ways forward for NTP to strengthen the TB diagnostics and treatment services in Nepal. Methods: This study is based on the review of available literatures and data sources related to tuberculosis prevention, care and control. Secondary data published by National Tuberculosis Program in the annual report for the year 2015, 2016 and 2017 were considered for the situation analysis of tuberculosis in Nepal. We used different platforms like Google scholar, PubMed to search relevant literatures. Results: This has been a huge gap between WHO TB estimates and TB cases notification by the national system. It was 22% in 2015, 27% in 2016 and 29% in 2017. However National Tuberculosis Program has maintained treatment success rate consistently above 90%. Tuberculosis program has yet not achieved universal HIV testing, although HIV testing among TB patients has increased rapidly. Similarly, only 75%, 1994 received DST out of 2601 retreatment TB cases have received DST in 2017 despite guideline suggest mandatory drug susceptibility testing for retreatment TB cases. Conclusion: Case notification has reduced gradually. It is difficult to achieve the target envisioned by NSP 2016-21 if the current case notification trend persists. NTP needs to expand service sites ensuring minimum quality standards as well as scale up targeted intervention addressing human right issues to identify the missing TB cases. NTP needs to regulate the quality of diagnosis and treatment TB services offered by private sector.  

Congenital Zika Virus Infection in Immunocompetent Mice Causes Postnatal Growth Impediment and Neurobehavioral Deficits

A small percentage of babies born to Zika virus (ZIKV)-infected mothers manifest severe defects at birth, including microcephaly. Among those who appeared healthy at birth, there are increasing reports of postnatal growth or developmental defects. However, the impact of congenital ZIKV infection in postnatal development is poorly understood. Here, we report that a mild congenital ZIKV-infection in pups born to immunocompetent pregnant mice did not display apparent defects at birth, but manifested postnatal growth impediments and neurobehavioral deficits, which include reduced locomotor and cognitive deficits that persisted into adulthood. We found that the brains of these pups were smaller, had a thinner cortical layer 1, displayed increased astrogliosis, decreased expression of microcephaly- and neuron development- related genes, and increased pathology as compared to mock-infected controls. In summary, our results showed that even a mild congenital ZIKV infection in immunocompetent mice could lead to postnatal deficits, providing definitive experimental evidence for a necessity to closely monitor postnatal growth and development of presumably healthy human infants, whose mothers were exposed to ZIKV infection during pregnancy.

Assessment of Critical Knowledge on Maternal and Newborn care Services among Primary Level Nurse Mid-wives in Kapilvastu District of Nepal

Background Despite greater emphasis on maternal and neonatal health through policy and programming in Nepal, maternal and neonatal health is still not impressive. Health care providers' knowledge assessment on maternal and neonatal care has been well documented elsewhere, but it is very little understood in Nepal. Objective The primary objective of this study was to assess the critical knowledge of primary level nurse- midwives on maternal and newborn care in Kapilvastu District of Nepal. Method This was an Institution based cross-sectional study, conducted in Kapilvastu district, Nepal among sixty eight nurse-midwives. The participants were selected using simple random sampling technique. For collecting the data, health institutions were visited by enumerators for a month from 1st October to 1st November 2012. Data were entered into Microsoft Excel, cleaned and analyzed using SPSS version 17.0. Result More than 3/4th of the nurse-midwives had 10-20 years of experience. Majority of them (89.7%) had poor knowledge in taking action to prevent mother to child transmission for HIV positive women. More than half of them (54.4%) had some knowledge in performing the active management of third stage of labor whereas almost half (51.5%) had poor knowledge to actions needed on post-partum haemorrhage (PPH). Similarly, more than two third (69.1%) had poor knowledge in newborn care. Conclusion Majority of the nurse-midwives were found to have either poor or some level of knowledge in most of the components of maternal and newborn care services. So, greater emphasis should be given to upgrade the knowledge of nurse mid-wives.

Osteopontin facilitates West Nile virus neuroinvasion via neutrophil "Trojan horse" transport

West Nile virus (WNV) can cause severe human neurological diseases including encephalitis and meningitis. The mechanisms by which WNV enters the central nervous system (CNS) and host-factors that are involved in WNV neuroinvasion are not completely understood. The proinflammatory chemokine osteopontin (OPN) is induced in multiple neuroinflammatory diseases and is responsible for leukocyte recruitment to sites of its expression. In this study, we found that WNV infection induced OPN expression in both human and mouse cells. Interestingly, WNV-infected OPN deficient (Opn ^-/-) mice exhibited a higher survival rate (70%) than wild type (WT) control mice (30%), suggesting OPN plays a deleterious role in WNV infection. Despite comparable levels of viral load in circulating blood cells and peripheral organs in the two groups, WNV-infected polymorphonuclear neutrophil (PMN) infiltration and viral burden in brain of Opn ^-/- mice were significantly lower than in WT mice. Importantly, intracerebral administration of recombinant OPN into the brains of Opn ^-/- mice resulted in increased WNV-infected PMN infiltration and viral burden in the brain, which was coupled to increased mortality. The overall results suggest that OPN facilitates WNV neuroinvasion by recruiting WNV-infected PMNs into the brain.

Effect of Maternal Socio-demographic Factors and Child Feeding Practice on Wasting Among Under Five Years Children in Slum Area of Rupandehi District in Nepal

INTRODUCTION

Childhood wasting although well studied elsewhere, it has not been well understood about in slum area of Nepal. This study aimed to assess effect of socio-demographic factors and child feeding practice in the determination of wasting among the children under five years of age in slum area of Nepal.

METHODS

A community based cross-sectional study was performed among 150 children under five years of age from the slum area of Nepal between 1st January and 28th February 2013 using simple random sampling techniques. Multivariate analyses were performed to determine factors associated with wasting controlling the potential confounders.

RESULTS

In a total of 150 under five years children, the prevalence of wasting was 56 (37.33%). The current study demonstrated that children of mothers from dalit Adjusted Odds Ratio (OR) 11.5; 95% CI: 03.1 - 41.3), aadibasi/janajati (AOR 4.6; 95% CI: 1.2 - 17.0), illiterate mothers (AOR 3.6; 95% CI: 1.1 - 13.6), laborer mothers (AOR 2.1; 95% CI: 1.1-9.4), child age group 25-36 months (AOR 2.8; 95% CI: 1.5-5.3), multiple child birth order (AOR 10.0; 95% CI: 2.5-25.0), children who were not fed colostrums (AOR 15.0; 95% CI: 1.25-10.0) were more likely to develop wasting compared to their counterparts.

CONCLUSIONS

As incremental childhood wasting is associated with maternal socio-demographic factors and child feeding practice, health promotion strategies should focus maternal socio-demographic factors, age of children and early initiation of breast feeding for the improved child nutrition in slum area of Nepal.

The Molecular Basis for the Lack of Inflammatory Responses in Mouse Embryonic Stem Cells and Their Differentiated Cells

We reported previously that mouse embryonic stem cells do not have a functional IFN-based antiviral mechanism. The current study extends our investigation to the inflammatory response in mouse embryonic stem cells and mouse embryonic stem cell-differentiated cells. We demonstrate that LPS, TNF-α, and viral infection, all of which induce robust inflammatory responses in naturally differentiated cells, failed to activate NF-κB, the key transcription factor that mediates inflammatory responses, and were unable to induce the expression of inflammatory genes in mouse embryonic stem cells. Similar results were obtained in human embryonic stem cells. In addition to the inactive state of NF-κB, the deficiency in the inflammatory response in mouse embryonic stem cells is also attributed to the lack of functional receptors for LPS and TNF-α. In vitro differentiation can trigger the development of the inflammatory response mechanism, as indicated by the transition of NF-κB from its inactive to active state. However, a limited response to TNF-α and viral infection, but not to LPS, was observed in mouse embryonic stem cell-differentiated fibroblasts. We conclude that the inflammatory response mechanism is not active in mouse embryonic stem cells, and in vitro differentiation promotes only partial development of this mechanism. Together with our previous studies, the findings described in this article demonstrate that embryonic stem cells are fundamentally different from differentiated somatic cells in their innate immunity, which may have important implications in developmental biology, immunology, and embryonic stem cell-based regenerative medicine.

Factors Associated with Smokeless Tobacco Use among Pregnant Women in Rural Areas of the Southern Terai, Nepal

BACKGROUND

Tobacco use among women during pregnancy leading to poor maternal and child health outcomes has been well documented. However, factors influencing use of smokeless tobacco in Nepal has not yet been well established. This study aims at exploring the factors related to smokeless tobacco use among pregnant women in rural southern Terai of Nepal.

METHODS

A community-based cross-sectional study was performed at 52 wards within 6 Village Development Committee in Dhanusha district of Nepal. A total of 426 expectant mothers in their second trimester were selected using a multistage cluster sampling method. Descriptive and regression analyses were done to explore the factors that influence smokeless tobacco use.

RESULTS

In a total of 426 pregnant mothers, one in five used tobacco in any form. Among the users, 13.4% used smokeless tobacco. Pregnant mothers who were smoking tobacco (AOR 6.01; 95% CI (1.88-19.23), having alcohol consumption (AOR 3.86; 95% CI (1.23-12.08), stressed (AOR 5.04; 95% CI (1.81-14.03), non-vegetarian (AOR 3.31;(1.84-13.03), not attending regular mothers' group meetings (AOR 4.63; (1.41-15.19), and not-exposed to mass media (AOR 5.02; (1.89-13.33) were significantly associated with smokeless tobacco use. Similarly, mothers of age group 20-34 years, dalit, aadibasi and janajati, hill origin, no education and primary education were more likely to use smokeless tobacco than their counterparts.

CONCLUSIONS

Factors such as smoking tobacco, alcohol consumption, stress, and poor education were found to be significantly associated with smokeless tobacco use among pregnant women in southern Terai of Nepal. This requires an immediate attention develop an effective strategy to prevent and control smokeless tobacco use among pregnant women in southern Terai of Nepal.

TLR8 Couples SOCS-1 and Restrains TLR7-Mediated Antiviral Immunity, Exacerbating West Nile Virus Infection in Mice

West Nile virus (WNV) is a neurotropic ssRNA flavivirus that can cause encephalitis, meningitis, and death in humans and mice. Human TLR7 and TLR8 and mouse TLR7 recognize viral ssRNA motifs and induce antiviral immunity. However, the role of mouse TLR8 in antiviral immunity is poorly understood. In this article, we report that TLR8-deficient (Tlr8^-/-) mice were resistant to WNV infection compared with wild-type controls. Efficient WNV clearance and moderate susceptibility to WNV-mediated neuronal death in Tlr8^-/- mice were attributed to overexpression of Tlr7 and IFN-stimulated gene-56 expression, whereas reduced expression of the proapoptotic gene coding Bcl2-associated X protein was observed. Interestingly, suppressor of cytokine signaling (SOCS)-1 directly associated with TLR8, but not with TLR7, indicating a novel role for TLR8 regulation of SOCS-1 function, whereas selective small interfering RNA knockdown of Socs-1 resulted in induced IFN-stimulated gene-56 and Tlr7 expression following WNV infection. Collectively, we report that TLR8 coupling with SOCS-1 inhibits TLR7-mediated antiviral immunity during WNV infection in mice.

Knowledge of Maternal and Newborn Care Among Primary Level Health Workers in Kapilvastu District of Nepal

BACKGROUND

Higher maternal and neonatal deaths are common in low- and middle-income countries; due to less access to skilled help. Adequate knowledge and skills on maternal and newborn care (MNC) of community health workers can improve maternal and newborn health.

AIMS

To identify the knowledge of primary level health workers on some components of MNC.

SUBJECTS AND METHODS

Respondents were selected using simple random sampling method. For collecting the data, enumerators visited health institutions for 2 months from 1(st) October to 31(st) November 2012, and structured interview schedule was used to gather the information. A cross-sectional study was conducted in a total of one hundred and thirty-seven primary level health workers in Kapilvastu district, Nepal. The Chi-square test was employed to examine the association between the knowledge of health workers on MNC and designation and work experience. Data were analyzed using SPSS version 17.

RESULTS

In a total of 137 primary level health workers, more than half 53.2% (73/137) were senior auxiliary health workers/health assistant. Health workers having correct knowledge on contents of MNC were-registration 32.1% (44/137), major components of antenatal care 57.7% (79/137), danger signs of pregnancy 39.4% (54/137), five cleans 59.1% (81/137), postnatal health problems 54.0% (74/137), majority to health action to newborn care, newborn bath and meaning of exclusive breastfeeding. There was a statistical association between designation of health workers and above-mentioned components of MNC (P < 0.05).

CONCLUSIONS

The differentials in the knowledge of MNC among primary level health suggest improving knowledge of the grass root level health workers with appropriate training and development programs.

A novel role for Osteopontin in facilitating West Nile virus neuroinvasion

West Nile virus (WNV) is a positive sense, single-stranded RNA flavivirus that can cause human neuroinvasive diseases, including encephalitis and meningitis. The mechanisms by which WNV enters the central nervous system (CNS) and the host-factors that are involved in WNV neuroinvasion are not completely understood. In this study, we found increased production of soluble osteopontin (OPN) in human plasma following WNV infection compared to uninfected controls, indicating a role for OPN in WNV pathogenesis. In a mouse model, after challenge with WNV (2000 plaque forming units, PFU), OPN deficient (Opn−/−) mice exhibited a higher survival percentage (80%) than wild-type (WT) mice (20%). However, both groups had comparable levels of virus in circulating blood and peripheral organs. Interestingly, viral burden in the brains of Opn−/− mice were significantly lower than WT mice, which was coupled to reduced polymorphonuclear neutrophil (PMN) infiltration. Soluble OPN has been previously described as a chemokine for PMN recruitment, and intracerebral supplement of recombinant OPN (50 ng/mouse) followed by an intraperitoneal challenge of WNV (2000 PFU), resulted in increased PMN infiltration and WNV load within the CNS. Furthermore, we also confirmed that infected-PMNs carried WNV into the CNS. Together, these data suggest OPN plays a negative role in recruiting WNV-infected PMNs into the CNS, thus mediating WNV neuroinvasion.

Development of Antiviral Innate Immunity During In Vitro Differentiation of Mouse Embryonic Stem Cells

The innate immunity of embryonic stem cells (ESCs) has recently emerged as an important issue in ESC biology and in ESC-based regenerative medicine. We have recently reported that mouse ESCs (mESCs) do not have a functional type I interferon (IFN)-based antiviral innate immunity. They are deficient in expressing IFN in response to viral infection and have limited ability to respond to IFN. Using fibroblasts (FBs) as a cell model, the current study investigated the development of antiviral mechanisms during in vitro differentiation of mESCs. We demonstrate that mESC-differentiated FBs (mESC-FBs) share extensive similarities with naturally differentiated FBs in morphology, marker expression, and growth pattern, but their development of antiviral mechanisms lags behind. Nonetheless, the antiviral mechanisms are inducible during mESC differentiation as demonstrated by the transition of nuclear factor kappa B (NFκB), a key transcription factor for IFN expression, from its inactive state in mESCs to its active state in mESC-FBs and by increased responses of mESC-FBs to viral stimuli and IFN during their continued in vitro propagation. Together with our previously published study, the current data provide important insights into molecular basis for the deficiency of IFN expression in mESCs and the development of antiviral innate immunity during mESC differentiation.

Loss of Glycosaminoglycan Receptor Binding after Mosquito Cell Passage Reduces Chikungunya Virus Infectivity

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that can cause fever and chronic arthritis in humans. CHIKV that is generated in mosquito or mammalian cells differs in glycosylation patterns of viral proteins, which may affect its replication and virulence. Herein, we compare replication, pathogenicity, and receptor binding of CHIKV generated in Vero cells (mammal) or C6/36 cells (mosquito) through a single passage. We demonstrate that mosquito cell-derived CHIKV (CHIKV_mos) has slower replication than mammalian cell-derived CHIKV (CHIKV_vero), when tested in both human and murine cell lines. Consistent with this, CHIKV_mos infection in both cell lines produce less cytopathic effects and reduced antiviral responses. In addition, infection in mice show that CHIKV_mos produces a lower level of viremia and less severe footpad swelling when compared with CHIKV_vero. Interestingly, CHIKV_mos has impaired ability to bind to glycosaminoglycan (GAG) receptors on mammalian cells. However, sequencing analysis shows that this impairment is not due to a mutation in the CHIKV E2 gene, which encodes for the viral receptor binding protein. Moreover, CHIKV_mos progenies can regain GAG receptor binding capability and can replicate similarly to CHIKV_vero after a single passage in mammalian cells. Furthermore, CHIKV_vero and CHIKV_mos no longer differ in replication when N-glycosylation of viral proteins was inhibited by growing these viruses in the presence of tunicamycin. Collectively, these results suggest that N-glycosylation of viral proteins within mosquito cells can result in loss of GAG receptor binding capability of CHIKV and reduction of its infectivity in mammalian cells.

Chikungunya virus (CHIKV) is a chronic arthritis-causing pathogen in humans, for which no licensed vaccine or specific antiviral drug is currently available. Due to the global spread of its mosquito vectors, CHIKV is now becoming a public health threat worldwide. CHIKV can replicate in both mammalian and mosquito cells, however it does not cause apparent damage to mosquito cells, yet it rapidly kills mammalian cells within a day after infection. In addition, mosquito and mammalian cells have different mechanism of protein glycosylation, which can result in different glycan structures of viral glycoproteins. In this study, we report that mosquito cell-generated CHIKV has lower infectivity in cell culture and causes less severe disease in mice, when compared to mammalian cell-generated CHIKV. We demonstrate that only mammalian cell-generated CHIKV, but not mosquito-cell generated CHIKV, binds to mammalian cell surface glycosaminoglycan receptors. Interestingly, mosquito-cell generated CHIKV can re-acquire glycosaminoglycan receptor binding capability after a single passage in mammalian cells and replicate at similar levels with mammalian cell-generated CHIKV, suggesting that passage of CHIKV in mosquito cells can reduce its infectivity.

Attenuated Innate Immunity in Embryonic Stem Cells and Its Implications in Developmental Biology and Regenerative Medicine

Embryonic stem cells (ESCs) represent a promising cell source for regenerative medicine. Intensive research over the past 2 decades has led to the feasibility of using ESC-differentiated cells (ESC-DCs) in regenerative medicine. However, increasing evidence indicates that ESC-DCs generated by current differentiation methods may not have equivalent cellular functions to their in vivo counterparts. Recent studies have revealed that both human and mouse ESCs as well as some types of ESC-DCs lack or have attenuated innate immune responses to a wide range of infectious agents. These findings raise important concerns for their therapeutic applications since ESC-DCs, when implanted to a wound site of a patient, where they would likely be exposed to pathogens and inflammatory cytokines. Understanding whether an attenuated immune response is beneficial or harmful to the interaction between host and grafted cells becomes an important issue for ESC-based therapy. A substantial amount of recent evidence has demonstrated that the lack of innate antiviral responses is a common feature to ESCs and other types of pluripotent cells. This has led to the hypothesis that mammals may have adapted different antiviral mechanisms at different stages of organismal development. The underdeveloped innate immunity represents a unique and uncharacterized property of ESCs that may have important implications in developmental biology, immunology, and in regenerative medicine.

Toll-like receptor 8 signaling facilitates West Nile virus infection in mice (VIR9P.1161)

West Nile virus (WNV) is a neurotropic virus that can cause encephalitis, meningitis or possible death in humans. Human and mouse Toll-like receptor 7 (h/mTLR7) and human Toll-like receptor 8 (hTLR8) detect viral single-stranded (ss)RNA motifs. Importantly, mTLR7 recognizes WNV, as TLR7-/- mice are susceptible to lethal WNV infection. However, the role of TLR8 in WNV pathogenesis is not clear. In this study, we found that mice deficient in TLR8 (TLR8-/-) infected with WNV (2,000 plaque forming units) had improved percentage survival (65%) compared to wild-type (WT) controls (25%), which was coupled to reduced viral burden in the brains of TLR8-/- mice. These data suggest that TLR8 signaling facilities WNV infection in mice. Further mechanistic studies showed that expression of TLR7 and the interferon-induced anti-viral gene Isg-56 (IFIT-1) were significantly increased in TLR8-/- mice whole-brain samples and mixed neuronal cultures following WNV infection, compared to WT controls. These results indicate that TLR8 signaling may down-regulate TLR7 and Isg-56 expression, thus promoting WNV-induced neuroinvasive disease.

In vitro Temocillin efficacy against extended spectrum β-lactamase producing multidrug resistant gram negative bacterial isolates from Nepal

Temocillin is relatively more stable against most β-lactamases and requires re-evaluation to include it in common clinical practice as a therapeutic alternative. At the National Reference Laboratory of Nepal, we evaluated multidrug resistance (MDR) and extended spectrum β-lactamase (ESBL) phenotypes among 292 gram-negative clinical bacterial isolates of 18 different genera during 2009/2010 by Kirby-Bauer disc diffusion method following CLSI guidelines. ESBL screen positive isolates were tested for Temocillin efficacy by disc diffusion method following British Society of Antimicrobial Chemotherapy (BSAC) guidelines and other antibiotics following Clinical and Laboratory Standards Institute (CLSI) guidelines. Of the 292 isolates, 75.0% isolates were MDR, among which 61.6% were primarily screened positive for ESBL production but only 38.8% were confirmed as ESBL producers. We report relatively lower Temocillin resistance of 28.9% and 15.6% among MDR and ESBL positive populations, respectively. Among ESBL positive isolates, no Proteus mirabilis, 19.7% Escherichia coli and 33.3% Klebsiella oxytoca showed resistance to Temocillin, although such resistance was higher among Acinetobacter spp. (66.7%) and K. pneumoniae 50.0%. Among ESBL negative isolates, none of the K. oxytoca and few (13.3%) Acinetobacter spp. were resistant to Temocillin, while all Citrobacter freundii, Pseudomonas aeruginosa (85.7%) and K. pneumoniae (66.7%) showed Temocillin resistance. Only 14.8% and 3.0% of total MDR isolates were resistant to Imipenem and Meropenem, respectively. However, Imipenem resistance was remarkably high (86.7%) among ESBL negative Acinetobacter spp. than Meropenem (13.3%). Temocillin showed comparable efficacy against MDR and ESBL producing bacterial isolates and could be a next therapeutic option.

Antiviral responses in mouse embryonic stem cells: differential development of cellular mechanisms in type I interferon production and response

We have recently reported that mouse embryonic stem cells (mESCs) are deficient in expressing type I interferons (IFNs) in response to viral infection and synthetic viral RNA analogs (Wang, R., Wang, J., Paul, A. M., Acharya, D., Bai, F., Huang, F., and Guo, Y. L. (2013) J. Biol. Chem. 288, 15926-15936). Here, we report that mESCs are able to respond to type I IFNs, express IFN-stimulated genes, and mediate the antiviral effect of type I IFNs against La Crosse virus and chikungunya virus. The major signaling components in the IFN pathway are expressed in mESCs. Therefore, the basic molecular mechanisms that mediate the effects of type I IFNs are functional in mESCs; however, these mechanisms may not yet be fully developed as mESCs express lower levels of IFN-stimulated genes and display weaker antiviral activity in response to type I IFNs when compared with fibroblasts. Further analysis demonstrated that type I IFNs do not affect the stem cell state of mESCs. We conclude that mESCs are deficient in type I IFN expression, but they can respond to and mediate the cellular effects of type I IFNs. These findings represent unique and uncharacterized properties of mESCs and are important for understanding innate immunity development and ESC physiology.

Delivery of antiviral small interfering RNA with gold nanoparticles inhibits dengue virus infection in vitro

Dengue virus (DENV) infection in humans can cause flu-like illness, life-threatening haemorrhagic fever or even death. There is no specific anti-DENV therapeutic or approved vaccine currently available, partially due to the possibility of antibody-dependent enhancement reaction. Small interfering RNAs (siRNAs) that target specific viral genes are considered a promising therapeutic alternative against DENV infection. However, in vivo, siRNAs are vulnerable to degradation by serum nucleases and rapid renal excretion due to their small size and anionic character. To enhance siRNA delivery and stability, we complexed anti-DENV siRNAs with biocompatible gold nanoparticles (AuNPs) and tested them in vitro. We found that cationic AuNP-siRNA complexes could enter Vero cells and significantly reduce DENV serotype 2 (DENV-2) replication and infectious virion release under both pre- and post-infection conditions. In addition, RNase-treated AuNP-siRNA complexes could still inhibit DENV-2 replication, suggesting that AuNPs maintained siRNA stability. Collectively, these results demonstrated that AuNPs were able to efficiently deliver siRNAs and control infection in vitro, indicating a novel anti-DENV strategy.

Preliminary anti-cancer photodynamic therapeutic in vitro studies with mixed-metal binuclear ruthenium(II)-vanadium(IV) complexes

We report the synthesis and characterisation of mixed-metal binuclear ruthenium(II)-vanadium(IV) complexes, which were used as potential photodynamic therapeutic agents for melanoma cell growth inhibition. The novel complexes, [Ru(pbt)2(phen2DTT)](PF6)2·1.5H2O 1 (where phen2DTT = 1,4-bis(1,10-phenanthrolin-5-ylsulfanyl)butane-2,3-diol and pbt = 2-(2'-pyridyl)benzothiazole) and [Ru(pbt)2(tpphz)](PF6)2·3H2O 2 (where tpphz = tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]phenazine) were synthesised and characterised. Compound 1 was reacted with [VO(sal-L-tryp)(H2O)] (where sal-L-tryp = N-salicylidene-L-tryptophanate) to produce [Ru(pbt)2(phen2DTT)VO(sal-L-tryp)](PF6)2·5H2O 4; while [VO(sal-L-tryp)(H2O)] was reacted with compound 2 to produce [Ru(pbt)2(tpphz)VO(sal-L-tryp)](PF6)2·6H2O 3. All complexes were characterised by elemental analysis, HRMS, ESI MS, UV-visible absorption, ESR spectroscopy, and cyclic voltammetry, where appropriate. In vitro cell toxicity studies (with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay) via dark and light reaction conditions were carried out with sodium diaqua-4,4',4'',4''' tetrasulfophthalocyaninecobaltate(II) (Na4[Co(tspc)(H2O)2]), [VO(sal-L-tryp)(phen)]·H2O, and the chloride salts of complexes 3 and 4. Such studies involved A431, human epidermoid carcinoma cells; human amelanotic malignant melanoma cells; and HFF, non-cancerous human skin fibroblast cells. Both chloride salts of complexes 3 and 4 were found to be more toxic to melanoma cells than to non-cancerous fibroblast cells, and preferentially led to apoptosis of the melanoma cells over non-cancerous skin cells. The anti-cancer property of the chloride salts of complexes 3 and 4 was further enhanced when treated cells were exposed to light, while no such effect was observed on non-cancerous skin fibroblast cells. ESR and (51)V NMR spectroscopic studies were also used to assess the stability of the chloride salts of complexes 3 and 4 in aqueous media at pH 7.19. This research illustrates the potential for using mixed-metal binuclear ruthenium(II)-vanadium(IV) complexes to fight skin cancer.

Mouse embryonic stem cells are deficient in type I interferon expression in response to viral infections and double-stranded RNA

Embryonic stem cells (ESCs) are considered to be a promising cell source for regenerative medicine because of their unlimited capacity for self-renewal and differentiation. However, little is known about the innate immunity in ESCs and ESC-derived cells. We investigated the responses of mouse (m)ESCs to three types of live viruses as follows: La Crosse virus, West Nile virus, and Sendai virus. Our results demonstrated mESCs were susceptible to viral infection, but they were unable to express type I interferons (IFNα and IFNβ, IFNα/β), which differ from fibroblasts (10T1/2 cells) that robustly express IFNα/β upon viral infections. The failure of mESCs to express IFNα/β was further demonstrated by treatment with polyIC, a synthetic viral dsRNA analog that strongly induced IFNα/β in 10T1/2 cells. Although polyIC transiently inhibited the transcription of pluripotency markers, the stem cell morphology was not significantly affected. However, polyIC can induce dsRNA-activated protein kinase in mESCs, and this activation resulted in a strong inhibition of cell proliferation. We conclude that the cytosolic receptor dsRNA-activated protein kinase is functional, but the mechanisms that mediate type I IFN expression are deficient in mESCs. This conclusion is further supported by the findings that the major viral RNA receptors are either expressed at very low levels (TLR3 and MDA5) or may not be active (retinoic acid-inducible gene I) in mESCs.

Ciprofloxacin susceptibility of Salmonella enteric serovar Typhi and Paratyphi A from blood samples of suspected enteric fever patients

INTRODUCTION: Enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi A is the common clinical diagnosis among febrile patients presenting to hospital in Nepal. The aim of this study was to evaluate the ciprofloxacin (CIP) and other antibiotics susceptibility patterns of Salmonella enterica serovars Typhi and Paratyphi A from blood samples of suspected enteric fever patients visiting KIST Medical College, Kathmandu. MATERIALS AND METHODS: Antibiotic susceptibility test was performed by Kirby Bauer disc diffusion method as per CLSI guidelines whereas MIC determination of ciprofloxacin was performed by agar dilution method. RESULTS: Altogether 64 presumptive Salmonella spp. were isolated from 840 blood samples of suspected enteric fever patients, of which 41 were S. Typhi and 23 were S. Paratyphi A. All Salmonella spp. isolates were sensitive to ceftriaxone and ofloxacin whereas 4 isolates were resistant to ciprofloxacin. One isolates each of S. Typhi and S. Paratyphi A were multidrug resistant. Fifty five isolates of Salmonella spp. were resistant to nalidixic acid (NA) with higher rate in S. Paratyphi A (91.3%) compared to S. Typhi (82.9%). MIC determination of ciprofloxacin revealed that majority of the isolates were resistant to ciprofloxacin and 2 isolates were resistant with MIC value of 4 µg/ml and 8 µg/ml. Importantly, we found simultaneous presence of NA resistance and decreased susceptibility to CIP suggesting that resistance to NA is a reliable indicator of decreased CIP susceptibility. CONCLUSIONS: Disc diffusion test failed to detect the reduced susceptibility of ciprofloxacin. Hence the MIC determination of ciprofloxacin against Salmonella spp. isolates would be important.  DOI: http://dx.doi.org/10.3126/ijim.v1i1.6938Int J Infect Microbiol 2012;1(1):9-13

Current fluoroquinolone susceptibility criteria for Salmonella needs re-evaluation

BACKGROUND

Disc diffusion technique is the routine susceptibility testing procedure for isolates of enteric fever, the most common clinical diagnosis among febrile patients in Nepal.

OBJECTIVE

To evaluated the current fluoroquinolones (FQs) susceptibility criteria and nalidixic acid screening test in Salmonella enterica serovar Typhi and Paratyphi A.

METHODS

S. Typhi and Paratyphi A strains isolated from 443 suspected enteric fever patients visiting National Public Health Laboratory (NPHL) during April through October 2008 were analyzed. All isolates were confirmed by standard microbiological procedures including serotyping. Antibiotic susceptibility testing was performed by using Kirby Bauer disc diffusion method and Clinical and Laboratory Standards Institute (CLSI) approved interpretive criteria. Agar dilution method was used to determine Minimum Inhibitory Concentration (MIC) of ciprofloxacin, ofloxacin and nalidixic acid.

RESULT

Out of 41 Salmonella isolates, 80.49% were nalidixic acid resistant, with S. Paratyphi A showing higher resistance rate (88.23%) compared to S. Typhi (75%). The difference in both MIC and zone diameter in nalidixic acid susceptible and nalidixic acid resistant isolates was found to be significant (P < 0.001) and decreased susceptibility to FQs was strongly correlated (sensitivity and specificity of 100%) with resistance to nalidixic acid. Regression analysis of MIC against zone diameter based on the current CLSI recommended guidelines suggests that accommodation of current susceptible and resistant MIC requires increase in the zone diameter of ciprofloxacin and ofloxacin.

CONCLUSION

Before using these drugs for management of enteric fever, appropriate identification of Salmonella isolates with reduced susceptibility to FQs is essential to limit the possible treatment failure and development of highly resistant strains. The current FQs susceptibility break point criteria for Salmonella need re-evaluation.

Diagnostic dilemma of the single screening test used in the diagnosis of syphilis in Nepal

Syphilis screening by the nontreponemal rapid plasma reagin (RPR) test is not usually followed up by specific treponemal tests in most of the resource poor healthcare settings of Nepal. We analyzed serum specimens of 504 suspected syphilis cases at the immunology department of the national reference laboratory in Nepal during 2007-2009 using RPR test and Treponema pallidum hemagglutination assay (TPHA). In overall, 35.7% were positive by both methods (combination) while 13.1% were RPR positive and TPHA negative, 8.7% were positive by TPHA only and 42.5% were negative by both methods. Among the RPR reactive (n = 246), 73.2% were positive by TPHA. Non-specific agglutination in RPR testing was relatively higher (26.8%) compared to TPHA (19.6%). Although TPHA was found more specific than RPR test, either of the single tests produced inaccurate diagnosis. Since the single RPR testing for syphilis may yield false positive results, specific treponemal test should be routinely used as confirmatory test to rule out false RPR positive cases. More attention needs to be paid on formulation of strict policy on the implementation of the existing guidelines throughout the country to prevent misdiagnosis in syphilis with the use of single RPR test.

Salmonella enterica serovar Paratyphi A: an emerging cause of febrile illness in Nepal

With an aim to evaluate the isolation rate and antibiotic susceptibility pattern in Salmonella enterica serovar Typhi and S. Paratyphi A, 656 blood samples collected from clinically diagnosed enteric fever patients at National Public Health Laboratory, Nepal during January through December 2008 were processed. Isolates were identified by standard microbiological procedures including serotyping. Antibiotic susceptibility testing was performed by disc diffusion method and minimum inhibitory concentration (MIC) to ciprofloxacin, ofloxacin and nalidixic acid was determined by agar dilution method following CLSI guidelines. Altogether 59 isolates of S. Typhi (49.15%) and S. Paratyphi A (50.85%) were recovered. A total of 80% isolates were resistant to nalidixic acid with S. Paratyphi A (93%) showing significantly higher resistance (P < 0.05) compared to S. Typhi (66%). The nalidixic acid resistant S. Paratyphi A strains required significantly higher MICs (P < 0.001) to quinolone (MIC expressed as mean +/- SD for nalidixic acid 477.87 +/- 87.02 microg/mL, ofloxacin 1.8 +/- 0.63 microg/mL, ciprofloxacin 0.62 +/- 0.3 microg/mL) compared with that of S. Typhi (nalidixic acid 173.18 +/- 72.03 microg/mL, ofloxacin 0.43 +/- 0.11 microg/mL, ciprofloxacin 0.25 microg/mL). Increased MIC of fluoroquinolone (FQ) is of particular concern in emerging strains of S. Paratyphi A as exposure to these drugs fuels up further development of full FQ resistant populations. Use of FQs as the first-line drugs for empirical therapy and management of enteric fever in areas where these strains are prevalent is questionable and requires an urgent review.

Resistotypes of Vibrio cholerae 01 Ogawa Biotype El Tor in Kathmandu, Nepal

Cholera continued to be a major diarrheal illness in Nepal and antibiotic resistance has appeared as a serious problem in cholera management. The study aimed at analyzing the distribution pattern of the resistotypes (R-types) of Vibrio cholerae in the Kathmandu valley, Nepal. During June 2008 to January 2009, 210 diarrheal specimens received at National Public Health Laboratory from suspected cholera patients were subjected to standard bacteriological investigation including biotyping and serotyping. Antimicrobial susceptibility pattern of V. cholerae isolates was determined by Kirby Bauer disc diffusion method following CLSI guidelines. A total of 57 (27%) V. cholerae isolated were recovered, all of which belonged to 01 Ogawa Biotype EL Tor. Based on antibiogram, V. cholerae isolates in our study revealed three distinct R-types: R-type I, R-type II and R-type III. All three R types showed resistance to furazolidone, nalidixic acid and cotrimoxazole while sensitive to ciprofloxacin and tetracycline. Additional resistance to ampicillin and erythromycin was observed respectively in R-type II and III. Different R-types showed unique month wise variations (P < 0.05). Differentiation of V. cholerae strains into R-types is an important tool. In addition to direct patient management, it may have implication in identifying the source and spread of infection, and understanding the distribution pattern in a particular geographical region.

Asymptomatic throat carriage rate and antimicrobial resistance pattern of Streptococcus pyogenes in Nepalese school children

BACKGROUND

Streptococcus pyogenes or Group A streptococcus (GAS) causes several suppurative and non suppurative infections. In addition to pharyngitis and skin infections, GAS are also the causative agent of post-streptococcal infection syndromes such as acute rheumatic fever (ARF) and post-streptococcal glumerulonephritis (PSG). GAS frequently colonises in the throat of an asymptomatic person. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons.

OBJECTIVES

We carried out this preliminary study to determine the throat carriage rate and antimicrobial resistance trend of Streptococcus pyogenes or Group A streptococcus (GAS) among the Nepalese school children.

MATERIALS AND METHODS

Four schools situated at different locations of Kathmandu valley were included in the study. Throat swabs from 350 students of age group 5-15 years were collected, immediately transported to the laboratory and were processed for S. pyogenes following standard microbiological procedures. Antimicrobial susceptibility testing of the isolates was performed by Kirby Bauer disc diffusion method following CLSI guidelines.

RESULTS

S. pyogenes was isolated from 10.9% (38/350) of the screened children. The GAS colonisation rate was statistically insignificant (P>0.05) with sex and age sub-groups, although the rate was slightly higher among girls and age sub-group 9-12 years. No significant difference in carrier rate was observed among different schools (P>0.05). All isolates were susceptible to azithromycin. No resistance was detected for penicillin and its derivative antibiotic ampicillin. Highest resistance rate was observed for cotrimoxazole (71.0%) followed by chloramphenicol (7.8%), ciprofloxacin (5.2%) and erythromycin (5.2%).

CONCLUSION

Antibiotic resistant GAS isolated from asymptomatic Nepalese school children is a public health concern. When screened and appropriately treated with antibiotics, carriers can be prevented from spreading of streptococcal infections in the school environment and the community. Preventing cross infections would ultimately reduce the incidence of life-threatening sequelae which are debilitating and difficult to treat. It is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimise GAS carriage/infections and resistance.

Prevalence of goitre among school children in Belgaum district

OBJECTIVE

A school survey was conducted to estimate the prevalence of goitre among schoolchildren in Belgaum district.

METHODS

A cross-sectional study was conducted in primary, middle and high schools of villages selected. All the children of the selected schools were examined for the presence of goitre and the salt samples obtained from their homes were tested for iodine content.

RESULTS

Overall prevalence of goitre was 16.7%. Prevalence of palpable goitre was 16.4 % and visible goitre was very low (0.3%). Higher prevalence was found among females (21.1%) when compared to that of male children (12.8 %). Prevalence of goitre increased significantly with advancement of age until 16-yr. 72.1 % children were consuming rock salt and only 27.9 % were consuming powdered salt at their homes. Estimation of Iodine content in the salt samples showed that 68.7 % of the sample had inadequate iodine content. Prevalence of goitre was significantly high among children who consumed rock salt (16.2%) as compared to those who used powdered salt (11%)

CONCLUSION

Strict implementation of salt codization and marketing in rural area is desired. Also health education programme be showed.