BackgroundIn resource limited settings acute febrile illnesses are often treated empirically due to a lack of reliable, rapid point-of-care diagnostics. This contributes to the indiscriminate use of antimicrobial drugs and poor treatment outcomes. The aim of this comprehensive review was to summarize the diagnostic performance of host biomarkers capable of differentiating bacterial from non-bacterial infections to guide the use of antibiotics.MethodsOnline databases of published literature were searched from January 2010 through April 2015. English language studies that evaluated the performance of one or more host biomarker in differentiating bacterial from non-bacterial infection in patients were included. Key information extracted included author information, study methods, population, pathogens, clinical information, and biomarker performance data. Study quality was assessed using a combination of validated criteria from the QUADAS and Lijmer checklists. Biomarkers were categorized as hematologic factors, inflammatory molecules, cytokines, cell surface or metabolic markers, other host biomarkers, host transcripts, clinical biometrics, and combinations of markers.FindingsOf the 193 citations identified, 59 studies that evaluated over 112 host biomarkers were selected. Most studies involved patient populations from high-income countries, while 19% involved populations from low- and middle-income countries. The most frequently evaluated host biomarkers were C-reactive protein (61%), white blood cell count (44%) and procalcitonin (34%). Study quality scores ranged from 23.1% to 92.3%. There were 9 high performance host biomarkers or combinations, with sensitivity and specificity of ≥85% or either sensitivity or specificity was reported to be 100%. Five host biomarkers were considered weak markers as they lacked statistically significant performance in discriminating between bacterial and non-bacterial infections.DiscussionThis manuscript provides a summary of host biomarkers to differentiate bacterial from non-bacterial infections in patients with acute febrile illness. Findings provide a basis for prioritizing efforts for further research, assay development and eventual commercialization of rapid point-of-care tests to guide use of antimicrobials. This review also highlights gaps in current knowledge that should be addressed to further improve management of febrile patients.

Human cytomegalovirus (HCMV), a herpesvirus, is an obligate parasite whose life cycle requires an intricate set of interactions between the virus and the host that optimize the environment for viral replication and assembly (for a review, see reference 14). Intertwined with this subversion of the host cell is a defined temporal order of viral gene expression that has been loosely divided into three phases-immediate early (IE), early, and late. The IE gene products are synthesized soon after infection and rely primarily on host factors for their expression, although proteins carried in the viral particle clearly contribute to the process. Several of the viral IE proteins serve as essential transactivators of the next class of gene products, the early genes. Included in the early class are those viral proteins required to "activate" the cell to a metabolic state most conducive for viral DNA synthesis and those proteins involved in the actual replication process itself. Late genes, which constitute the majority of the viral genome and encode primarily structural and maturation proteins, are transcribed in abundance only after the onset of viral DNA replication.Upon infection, the viral DNA enters the nucleus and a subset of HCMV genomes are deposited at nuclear structures referred to variously as nuclear domain 10 (ND10) structures or promyelocytic leukemia protein (PML) oncogenic domains (PODs), where viral RNA synthesis begins (21,22). The HCMV tegument protein pp71 interacts with POD-associated Daxx, which may contribute to the initiation of transcription at POD sites (9,20,23,28). The proximity of the PODs to the spliceosome assembly factor SC35 domains may aid in rapid expression of IE genes, which are often multiply spliced (22). A major region of viral IE transcription includes two genetic units, IE1 and IE2 (for reviews, see references 15 and 31). The predominant IE RNA (IE1) consists of four exons; a single open reading frame (ORF) (UL123) initiates in exon 2 and specifies a 72-kDa nuclear protein designated IE1-72. The IE2 gene product, IE2-86 (ORF UL122), is an 86-kDa protein that is encoded by an alternatively spliced RNA that contains the first three exons of IE1 and a different terminal exon. Another region of IE gene expression is UL36-38, which includes at least five transcripts directed by three promoters (1,26,49,50). One of the promoters directs the synthesis of several spliced 3.2-to 3.4-kb RNAs (UL37 and UL37 M ORFs) that are present in small amounts only at IE times as well as an abundant 1.7-kb unspliced RNA that encodes the UL37 exon 1 (UL37X1) gene product.Newly synthesized IE1-72 and IE2-86 localize to the PODs. While the punctate pattern of the IE2-86 protein persists, at 3 to 6 h postinfection (p.i.), both IE1-72 and POD-associated proteins become dispersed throughout the nucleus (5,22,24,25). Several studies have shown that IE2-86 is able to localize to the PODs in the absence of IE1-72 but is not able to disrupt

We previously reported that defined components of the host transcription machinery are recruited to human cytomegalovirus immediate-early (IE) transcription sites, including cdk9 and cdk7 (S. Tamrakar, A. J. Kapasi, and D. H. Spector, J. Virol. 79:15477-15493, 2005). In this report, we further document the complexity of this site, referred to as the transcriptosome, through identification of additional resident proteins, including viral UL69 and cellular cyclin T1, Brd4, histone deacetylase 1 (HDAC1), and HDAC2. To examine the role of cyclin-dependent kinases (cdks) in the establishment of this site, we used roscovitine, a specific inhibitor of cdk1, cdk2, cdk7, and cdk9, that alters processing of viral IE transcripts and inhibits expression of viral early genes. In the presence of roscovitine, IE2, cyclin T1, Brd4, HDAC1, and HDAC2 accumulate at the transcriptosome. However, accumulation of cdk9 and cdk7 was specifically inhibited. Roscovitine treatment also resulted in decreased levels of cdk9 and cdk7 RNA. There was a corresponding reduction in cdk9 protein but only a modest decrease in cdk7 protein. However, overexpression of cdk9 does not compensate for the effects of roscovitine on cdk9 localization or viral gene expression. Delaying the addition of roscovitine until 8 h postinfection prevented all of the observed effects of the cdk inhibitor. These data suggest that IE2 and multiple cellular factors needed for viral RNA synthesis accumulate within the first 8 h at the viral transcriptosome and that functional cdk activity is required for the specific recruitment of cdk7 and cdk9 during this time interval.

Objectives To compare genotypes of Mycobacterium bovis strains from humans in Southern California with genotypes of M. bovis strains in cattle in Mexico and the USA to explore the possible origins of human infections. Methods We conducted a descriptive analysis of M. bovis genotypes from a binational population of humans and cattle using spacer oligonucleotide typing (spoligotyping). Results One hundred six human M. bovis spoligotypes were compared to spoligotypes from 496 Mexican cattle and 219 US cattle. Twelve spoligotype patterns were identified among human cases and 126 spoligotype patterns were detected in cattle. Over 91% (97/106) of the human M. bovis isolates had spoligotypes that were identical to those found in Mexican cattle. Four human cases had spoligotypes that matched both cattle born in Mexico and in the USA. Nine human cases had spoligotypes that did not match cattle born in Mexico or the USA. Conclusions Our data indicate that the population of M. bovis strains causing human TB disease in Southern California is closely related to the M. bovis strain population found in Mexican cattle and supports existing epidemiological evidence that human M. bovis disease in San Diego likely originated from Mexican cattle.

Human cytomegalovirus (HCMV) infection results in the formation of nuclear viral transcriptosomes, which are sites dedicated to viral immediate-early (IE) transcription. At IE times of the infection, viral and cellular factors, including several components of transcription such as cyclin-dependent kinase 9 (cdk9), localize at these sites. To determine the mechanism and requirements of specific recruitment of cdk9 to the viral transcriptosomes, infection in the presence of inhibitor drugs and infection of cell lines expressing exogenous mutant cdk9 were performed. We found that cdk9 localization to the viral transcriptosomes requires de novo protein synthesis. In addition, active transcription is required for recruitment and maintenance of cdk9 at the viral transcriptosomes. In cells infected with a recombinant IE2 HCMV (IE2 86 ⌬SX virus) in which IE2 gene expression is greatly reduced, cdk9 localization at the transcriptosome is delayed and corresponds to the kinetics of accumulation of the IE2 protein at these sites. Infection in the presence of the cdk9 inhibitors Flavopiridol and DRB (5,6-dichloro-1-␤-D-ribofuranosylbenzimidazole) allowed cdk9 localization to the viral transcriptosomes. A kinase-inactive cdk9 (D167N) expressed during the infection also localizes to the viral transcriptosomes, indicating that kinase activity of cdk9 is not a requirement for its localization to the sites of IE transcription. Exogenous expression of additional cdk9 mutants indicates that binding of Brd4 to the cdk9 complex is not required but that efficient binding to cyclin T1 is essential.Human cytomegalovirus (HCMV) is a member of the Herpesviridae family and is of clinical concern in immunocompromised patients, organ transplant recipients, and the developing fetus (for a review, see reference 34). Congenital HCMV is the major viral cause of birth defects and can lead to permanent disabilities such as hearing and vision loss, mental disabilities, and even death. At present, there is no cure or available vaccine for treatment of HCMV.Immediately after the viral particles contact the cellular plasma membrane, many host functions are altered. It is a combination of the interactions between the virus and host that are established and the disruption of cellular functions that creates an optimal environment for viral replication (for a review, see reference 17). Viral gene expression is temporally regulated, beginning with the immediate-early (IE) genes. The IE genes do not require de novo cellular or viral protein synthesis for expression and can be classified as the set of viral transcripts that accumulate in the presence of cycloheximide (CHX). The IE gene products activate the expression of viral early genes, which in turn initiate and regulate viral DNA synthesis. After the onset of viral DNA synthesis, the late viral genes, which primarily encode structural proteins, are expressed, and that expression leads to the eventual release of virus from the cell.HCMV utilizes cellular RNA polymerase II (RNAP II) and the accompanying h...