23 research outputs found

    Phylogenetic analysis of Newcastle disease viruses isolated from waterfowl in the Upper Midwest Region of the United States

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    <p>Abstract</p> <p>Background</p> <p>This study was conducted to characterize Newcastle disease virus (NDV) isolates obtained from waterfowl from the Upper Midwest region of the United States. A total of 43 NDVs were isolated by inoculation of cloacal samples in embryonated chicken eggs. These isolates were obtained from 24 mallards, seven American green-winged teals, six northern pintails, four blue-winged teals, and two wood ducks. Partial sequences of fusion gene were analyzed to determine the pathotypes and genotypes involved.</p> <p>Results</p> <p>Deduced amino acid sequence of the cleavage site of fusion (F) protein revealed that all isolates had avirulent motifs. Of the 43 isolates, 23 exhibited sequence motif of <sup>111</sup>GGKQGRL<sup>117 </sup>at the cleavage site, 19 exhibited <sup>111</sup>GEKQGRL<sup>117 </sup>while one isolate showed <sup>111</sup>GERQGRL<sup>117</sup>. Phylogenetic analysis based on comparison with different classes of NDVs revealed that all 43 isolates clustered with class II NDVs and none with class I NDVs. Within class II, five isolates were phylogenetically close to genotype I NDVs while the remaining 38 were close to genotype II.</p> <p>Conclusion</p> <p>We conclude that more than one genotype of NDV circulates in waterfowl in the Upper Midwest region of the US. Continuous surveillance may help better understand the epidemiology of NDVs maintained in wild bird populations and their relationship to NDVs in domestic poultry, if any.</p

    Corrigendum: A Meta-Analysis of the Effect of Bacillus Calmette-Guérin Vaccination Against Bovine Tuberculosis:Is Perfect the Enemy of Good?

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    More than 50 million cattle are likely exposed to bovine tuberculosis (bTB) worldwide, highlighting an urgent need for bTB control strategies in low- and middle-income countries (LMICs) and other regions where the disease remains endemic and test-and-slaughter approaches are unfeasible. While Bacillus Calmette-Guérin (BCG) was first developed as a vaccine for use in cattle even before its widespread use in humans, its efficacy against bTB remains poorly understood. To address this important knowledge gap, we conducted a systematic review and meta-analysis to determine the direct efficacy of BCG against bTB challenge in cattle, and performed scenario analyses with transmission dynamic models incorporating direct and indirect vaccinal effects (“herd-immunity”) to assess potential impact on herd level disease control. The analysis shows a relative risk of infection of 0.75 (95% CI: 0.68, 0.82) in 1,902 vaccinates as compared with 1,667 controls, corresponding to a direct vaccine efficacy of 25% (95% CI: 18, 32). Importantly, scenario analyses considering both direct and indirect effects suggest that disease prevalence could be driven down close to Officially TB-Free (OTF) status (<0.1%), if BCG were introduced in the next 10-year time period in low to moderate (<15%) prevalence settings, and that 50–95% of cumulative cases may be averted over the next 50 years even in high (20–40%) disease burden settings with immediate implementation of BCG vaccination. Taken together, the analyses suggest that BCG vaccination may help accelerate control of bTB in endemic settings, particularly with early implementation in the face of dairy intensification in regions that currently lack effective bTB control programs

    Titanium dioxide-reduced graphene oxide hybrid as negative electrode additive for high performance lead-acid batteries

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    Sulfation at the negative electrode is one of the major failure modes of lead-acid batteries. To overcome the issues of sulfation, we herein report solvothermal synthesis of titanium dioxide- reduced graphene oxide hybrid as negative electrode additive in lead acid cell. The presence of titanium dioxide-reduced graphene oxide hybrid additive (0.5 wt. %) provides high interfacial stability, slows down hard sulfation, high active material utilization by occupying pores on the negative plate. 0.5 wt. % of titanium dioxide-reduced graphene oxide hybrid (3:1 wt. ratio) additive to the negative active mass delivers 85% increase in capacity during the first formation cycle, and thereby increases the formation efficiency from 3 cycles to 1 cycle; >20% and ∼200% increase in capacity at low discharge rates of C/20 and high rates of discharge (2C), respectively as compare to conventional lead acid cell. Besides, 3:1 wt. ratio titanium dioxide-reduced graphene oxide hybrid additive cells show ∼200% increase in high rate partial state of charge cycle life in relation to conventional cell. Titanium dioxide-reduced graphene oxide hybrid additives to the negative active mass provides increase in conductivity, controls the crystallization of lead sulphate growth, acts as a capacitor, decreases the hydrogen evolution and hence enhances the electrochemical performance

    Prevalence and epidemiology of Salmonella enterica serovar Gallinarum from poultry in some parts of Haryana, India

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    Aim: The present study was investigated to ascertain the epidemiological status of fowl typhoid (FT) in broilers in some parts of Haryana during January 2011 to December 2013. Materials and Methods: To elucidate the epidemiological status of FT in broiler chickens for the 3 years (2011-2013) and to study the prevalence of various Salmonella serovars in poultry on the basis of culture characteristics, biochemical features, serotyping, and their antibiogram profile from some parts of Haryana (India). Results: A total of 309 outbreaks of FT were recorded in chickens during this period. Overall percent morbidity, mortality, case-fatality rate (CFR) in broiler chicks due to FT during this period was 9.45, 6.77, and 71.55. The yearly observations were divided into quarters A (January-March), B (April-June), C (July-September) and D (October-December). Maximum number of outbreaks - 106 (34.3%) was recorded in quarter D followed by quarters B - 84 (27.3%), C - 64 (20.7%), and A - 55 (17.7%). Salmonella isolates (253) were recovered from disease outbreaks in broilers from different parts of Haryana. Typical morphology and colony characters on MacConkeys Lactose Agar and Brilliant Green agar, biochemical reactions, serotyping along with antibiogram profiles were able to group these isolates into 3 groups namely Salmonella Gallinarum (183), Salmonella Enteritidis (41) and Salmonella Typhimurium (29). The antibiogram pattern of 183 isolates of S. Gallinarum revealed that most of the isolates were sensitive to gentamicin (76%) followed by amikacin (72%), kanamycin (71%). Conclusion: FT is prevalent in commercial broiler flocks in different parts of Haryana and is responsible for considerably high morbidity and mortality in affected flocks. Isolation of S. Gallinarum (9, 12:183) from FT cases suggest it to be the primary pathogen, however, isolation of S. Typhimurium and S. Enteritidis from these cases is a major concern. The detection of S. Enteritidis and S. Typhimurium from FT cases assumes significance from public health point of view

    Carriage of Class 1 integrons and molecular characterization of intI1 gene in multidrug-resistant Salmonella spp. isolates from broilers

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    Aim: The present study was conducted with the following aims: (i) To screen the Salmonella spp. isolates recovered from suspected cases of fowl typhoid for carriage of Class 1 integrons and analyze their association with antimicrobial resistance and (ii) to carry out molecular characterization and phylogenetic analysis of Class 1 integron-integrase (intI1) gene. Materials and Methods: A total of 43 Salmonella isolates were subjected to polymerase chain reaction (PCR) assay to determine the presence of Class1 intI1. Differences between different serotypes in relation to their carriage of integrons and the differences between strains containing or not containing an integron and being resistant to different antimicrobials were analyzed by Fisher exact test using STATA™ (StataCorp, College Station, TX). Phylogenetic analysis was carried out using MEGA6 software. Results: Out of 43 isolates, 40 (93.02%) were found positive for Class 1 integrons. 35/40 (87.5%) intI1-positive isolates were multidrug resistance (MDR) (resistant to ≥4 antibiotics), which support the hypothesis of an association between the presence of Class 1 integrons and emerging MDR in Salmonella. There was no significant difference among isolates resistant to different antimicrobials in Class 1 integron carrying isolates and the Class 1 integron negative isolates (p<0.05). Further, there was no significant difference among different serotypes in respect of their carriage of Class 1 integrons. Conclusion: It can be concluded that the high prevalence of Class 1 integrons indicates a high potential of Salmonella isolates for horizontal transmission of antimicrobial genes, especially among Gram-negative organisms

    Molecular epidemiology, antibiogram profile and risk factor analysis of pathogenic Escherichia coli associated with pre-weaning diarrhoea in piglets from Haryana, India

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    Background: Piglet diarrhoea is a multifactorial disease with serious implications for the swine industry worldwide, including India. The Escherichia coli (E. coli) pathotypes, i.e., enterotoxigenic E. coli (ETEC) and Shiga toxin-producing E. coli (STEC) are among the major bacterial agents attributed as causative agent for piglet diarrhoea, but studies related to genetic diversity, antibiogram profile and their correlation with risk factors of these pathogens are sparse. Material and methods: A total of 104 faecal swab samples were collected from 32 different piggery units of Haryana, India and confirmed as E. coli by standard microbiological methods. The identified E. coli were characterized as ETEC and/or STEC using PCR assays and were studied for their genetic diversity by phylogenetic analysis of the sequences. All the isolates were subjected to antimicrobial susceptibility testing. Further, the correlation of variables with presence or absence of ETEC and/or STEC was also investigated by using Fisher’s exact test. Results: Microbiological isolation led to identification of 208 E. coli isolates. A total of 17.3% (31/208) isolates were characterized as ETEC and 4.8% (10/208) isolates as STEC, whereas 2.4% (5/208) isolates exhibited both ETEC and STEC pathotype. Of the total studied piggery units (n = 32), ETEC were isolated from fourteen and both ETEC and STEC from eight farms. The phylogenetic analysis of Stx2 gene revealed 100% homology with Stx2eA variant from Germany, while analysis of STII gene revealed a distinct nucleotide and amino acid substitution when compared with standard strains. The antibiotic susceptibility testing revealed maximum resistance to moxifloxacin (71.9%) followed by tetracycline (58.1%) and amoxicillin with a total of 41.8% (87/208) E. coli isolates designated as multi-drug resistant (MDR). The multiple antibiotic resistance index varied from 0.05 to 0.75. The statistical analysis suggested three factors viz., number of farm worker(s), frequency of using disinfectant for floor cleaning and use of antibiotic in feed as risk factors significantly associated (p < 0.05) with ETEC associated diarrhoea at piggeries under study. Conclusion: Current study warrants a need for systematic studies on the ETEC/STEC associated diarrhea and antibiotic resistance among these isolates to understand the mechanisms of origin and dissemination of drug resistant pathogens and to design suitable prevention and control measures to curb emergence of antibiotic resistance in the farm settings
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