The genome and proteome of a virulent Escherichia coli O157:H7 bacteriophage closely resembling Salmonella phage Felix O1

Based upon whole genome and proteome analysis, Escherichia coli O157:H7-specific bacteriophage (phage) wV8 belongs to the new myoviral genus, "the Felix O1-like viruses" along with Salmonella phage Felix O1 and Erwinia amylovora phage φEa21-4. The genome characteristics of phage wV8 (size 88.49 kb, mol%G+C 38.9, 138 ORFs, 23 tRNAs) are very similar to those of phage Felix O1 (86.16 kb, 39.0 mol%G+C, 131 ORFs and 22 tRNAs) and, indeed most of the proteins have their closest homologs within Felix O1. Approximately one-half of the Escherichia coli O157:H7 mutants resistant to phage wV8 still serotype as O157:H7 indicating that this phage may recognize, like coliphage T4, two different surface receptors: lipopolysaccharide and, perhaps, an outer membrane protein

Examination of animal and zoonotic pathogens using microarrays

The advancement in functional genomics, such as DNA microarrays along with the genome availability of important pathogens as well as of human and livestock species has allowed scientists to study the expression of thousands of genes in a single step. In the past decade, DNA arrays have been employed to study infectious processes of pathogens, in diagnostics, and to study host-pathogen interactions. The generation of enormous data sets by microarray experiments also stimulated the growth of a new generation of analytical software. The information provided by microarray experiments has been useful in generating new hypotheses for future research. The concept of DNA array technology has been utilized in the development of novel diagnostic methods. This review highlights the application of microarrays in the field of veterinary research

Identification of Actinobacillus suis Genes Essential for the Colonization of the Upper Respiratory Tract of Swine

Actinobacillus suis has emerged as an important opportunistic pathogen of high-health-status swine. A colonization challenge method was developed, and using PCR-based signature-tagged transposon mutagenesis, 13 genes belonging to 9 different functional classes were identified that were necessary for A. suis colonization of the upper respiratory tract of swine

Epidemiological and clinical characteristics of central nervous system infections in a tertiary center: A retrospective study

Abstract Background and Aims Central nervous system (CNS) infection is one of the most common causes of morbidity, mortality, and hospital admission worldwide. The natural history of CNS infection is quite fatal. Early diagnosis and treatment have been proven to have a crucial role in patients' survival. The aim of this study was to identify the epidemiological and clinical patterns of patients diagnosed with CNS infections. Methods This study is a retrospective study conducted in a tertiary level hospital in Nepal in which patient diagnosed with CNS infections (September 2019 to 2021) were included. Data were collected and analyzed in SPSS. Results The mean age of the 95 patients included in the study was 45.18 ± 19.56. Meningoencephalitis (n = 44, 46.30%) was the most common infection diagnosed. Patients belonging to the age group 30−60 years had a higher frequency of focal neurological deficit, and other classical clinical features. All the patients who died during the treatment had associated comorbidities but no concurrent infections. Altered sensorium, fever, and headache were the common presenting symptoms in all the recovered patients. Conclusion To ensure optimum disease outcome, early diagnosis and prompt management are crucial. For this, recognizing the local disease patterns in terms of disease distribution, commonly implicated aetiologies, presenting symptoms, and prognostic factors is of utmost importance

Endemic bacteriophages: a cautionary tale for evaluation of bacteriophage therapy and other interventions for infection control in animals

<p>Abstract</p> <p>Background</p> <p>One of the most effective targets for control of zoonotic foodborne pathogens in the farm to fork continuum is their elimination in food animals destined for market. Phage therapy for <it>Escherichia coli</it> O157:H7 in ruminants, the main animal reservoir of this pathogen, is a popular research topic. Since phages active against this pathogen may be endemic in host animals and their environment, they may emerge during trials of phage therapy or other interventions, rendering interpretation of trials problematic.</p> <p>Methods</p> <p>During separate phage therapy trials, sheep and cattle inoculated with 10⁹ to 10¹⁰ CFU of <it>E. coli</it> O157:H7 soon began shedding phages dissimilar in plaque morphology to the administered therapeutic phages. None of the former was previously identified in the animals or in their environment. The dissimilar “rogue” phage was isolated and characterized by host range, ultrastructure, and genomic and proteomic analyses.</p> <p>Results</p> <p>The “rogue” phage (Phage vB_EcoS_Rogue1) is distinctly different from the administered therapeutic <it>Myoviridae</it> phages, being a member of the <it>Siphoviridae</it> (head: 53 nm; striated tail: 152 x 8 nm). It has a 45.8 kb genome which is most closely related to coliphage JK06, a member of the “T1-like viruses” isolated in Israel. Detailed bioinformatic analysis reveals that the tail of these phages is related to the tail genes of coliphage lambda. The presence of “rogue” phages resulting from natural enrichments can pose problems in the interpretation of phage therapeutic studies. Similarly, evaluation of any interventions for foodborne or other bacterial pathogens in animals may be compromised unless tests for such phages are included to identify their presence and potential impact.</p