bluuebunny/crossref_metadata_2025 huggingface dataset:
Human and Animal Dirofilariasis: the Emergence of a Zoonotic Mosaic
Authors: Simón Fernando , Siles-Lucas Mar , Morchón Rodrigo , González-Miguel Javier , Mellado Isabel , Carretón Elena , Montoya-Alonso Jose Alberto
Published: July 2012

Dirofilariasis represents a zoonotic mosaic, which includes two main filarial species (Dirofilaria immitisandD. repens) that have adapted to canine, feline, and human hosts with distinct biological and clinical implications. At the same time, bothD. immitisandD. repensare themselves hosts to symbiotic bacteria of the genusWolbachia, the study of which has resulted in a profound shift in the understanding of filarial biology, the mechanisms of the pathologies that they produce in their hosts, and issues related to dirofilariasis treatment. Moreover, because dirofilariasis is a vector-borne transmitted disease, their distribution and infection rates have undergone significant modifications influenced by global climate change. Despite advances in our knowledge ofD. immitisandD. repensand the pathologies that they inflict on different hosts, there are still many unknown aspects of dirofilariasis. This review is focused on human and animal dirofilariasis, including the basic morphology, biology, protein composition, and metabolism ofDirofilariaspecies; the climate and human behavioral factors that influence distribution dynamics; the disease pathology; the host-parasite relationship; the mechanisms involved in parasite survival; the immune response and pathogenesis; and the clinical management of human and animal infections.
Molecular Biology, Epidemiology, and Pathogenesis of Progressive Multifocal Leukoencephalopathy, the JC Virus-Induced Demyelinating Disease of the Human Brain
Authors: Ferenczy Michael W. , Marshall Leslie J. , Nelson Christian D. S. , Atwood Walter J. , Nath Avindra , Khalili Kamel , Major Eugene O.
Published: July 2012

Progressive multifocal leukoencephalopathy (PML) is a debilitating and frequently fatal central nervous system (CNS) demyelinating disease caused by JC virus (JCV), for which there is currently no effective treatment. Lytic infection of oligodendrocytes in the brain leads to their eventual destruction and progressive demyelination, resulting in multiple foci of lesions in the white matter of the brain. Before the mid-1980s, PML was a relatively rare disease, reported to occur primarily in those with underlying neoplastic conditions affecting immune function and, more rarely, in allograft recipients receiving immunosuppressive drugs. However, with the onset of the AIDS pandemic, the incidence of PML has increased dramatically. Approximately 3 to 5% of HIV-infected individuals will develop PML, which is classified as an AIDS-defining illness. In addition, the recent advent of humanized monoclonal antibody therapy for the treatment of autoimmune inflammatory diseases such as multiple sclerosis (MS) and Crohn's disease has also led to an increased risk of PML as a side effect of immunotherapy. Thus, the study of JCV and the elucidation of the underlying causes of PML are important and active areas of research that may lead to new insights into immune function and host antiviral defense, as well as to potential new therapies.
Combination Therapy for Treatment of Infections with Gram-Negative Bacteria
Authors: Tamma Pranita D. , Cosgrove Sara E. , Maragakis Lisa L.
Published: July 2012

Combination antibiotic therapy for invasive infections with Gram-negative bacteria is employed in many health care facilities, especially for certain subgroups of patients, including those with neutropenia, those with infections caused byPseudomonas aeruginosa, those with ventilator-associated pneumonia, and the severely ill. An argument can be made for empiric combination therapy, as we are witnessing a rise in infections caused by multidrug-resistant Gram-negative organisms. The wisdom of continued combination therapy after an organism is isolated and antimicrobial susceptibility data are known, however, is more controversial. The available evidence suggests that the greatest benefit of combination antibiotic therapy stems from the increased likelihood of choosing an effective agent during empiric therapy, rather than exploitation ofin vitrosynergy or the prevention of resistance during definitive treatment. In this review, we summarize the available data comparing monotherapy versus combination antimicrobial therapy for the treatment of infections with Gram-negative bacteria.
Construction and Immunological Evaluation of Dual Cell Surface Display of HIV-1 Gag and Salmonella enterica Serovar Typhimurium FliC in Lactobacillus acidophilus for Vaccine Delivery
Authors: Kajikawa Akinobu , Zhang Lin , Long Julie , Nordone Shila , Stoeker Laura , LaVoy Alora , Bumgardner Sara , Klaenhammer Todd , Dean Gregg
Published: July 2012

Oral vaccines that elicit a mucosal immune response may be effective against human immunodeficiency virus type 1 (HIV-1) because its transmission occurs mainly at the mucosa. The aim of this study was to construct recombinant
Lactobacillus
for oral delivery of oral vaccines against HIV-1 and to evaluate their immunogenicity. A recombinant
Lactobacillus acidophilus
strain expressing the HIV-1 Gag on the bacterial cell surface was established by fusion with the signal peptide and anchor motif of a mucus binding protein (Mub) from
L. acidophilus
with or without coexpression of
Salmonella enterica
serovar Typhimurium flagellin (FliC) fused to a different Mub signal peptide and anchor. Using HEK293 cells engineered to express Toll-like receptor 5 (TLR5), the biological activity of FliC on the bacterial cell surfaces was determined. The surface-exposed flagellin retained its TLR5-stimulating activity, suggesting that the recombinant strain with Gag and FliC dual display might provide a different immunopotency than the strain expressing only Gag. The immunological properties of the recombinant strains were assessed by coculture with human myeloid dendritic cells (DCs). The heterologous antigens on the cell surface affected maturation and cytokine responses of DCs. Acquired immune responses were also investigated by intragastric immunization of mice. The enzyme-linked immunosorbent spot assay showed induction of gamma interferon-producing cells at local mucosa after immunization of mice with the Gag-producing strain. Meanwhile, the immunization with
L. acidophilus
displaying both Gag and FliC resulted in an increase of Gag-specific IgA-secreting cells. These results suggested that the Gag-displaying
L. acidophilus
elicited specific immune responses and the coexistence of FliC conferred an adjuvant effect on local IgA production.
Controlled Inflammatory Responses in the Lungs Are Associated with Protection Elicited by a Pneumococcal Surface Protein A-Based Vaccine against a Lethal Respiratory Challenge with Streptococcus pneumoniae in Mice
Authors: Lima Fernanda A. , Ferreira Daniela M. , Moreno Adriana T. , Ferreira Patrícia C. D. , Palma Giovana M. P. , Ferreira Jorge M. C. , Raw Isaias , Miyaji Eliane N. , Ho Paulo L. , Oliveira Maria Leonor S.
Published: July 2012

Streptococcus pneumoniae
is a pathogen of great importance worldwide. We have previously described the efficacy of a nasal vaccine composed of the pneumococcal surface protein A and the whole-cell pertussis vaccine as an adjuvant against a pneumococcal invasive challenge in mice. Spread of bacteria to the bloodstream was probably prevented by the high levels of systemic antibodies induced by the vaccine, but bacteria were only cleared from the lungs 3 weeks later, indicating that local immune responses may contribute to survival. Here we show that a strict control of inflammatory responses in lungs of vaccinated mice occurs even in the presence of high numbers of pneumococci. This response was characterized by a sharp peak of neutrophils and lymphocytes with a simultaneous decrease in macrophages in the respiratory mucosa at 12 h postchallenge. Secretion of interleukin-6 (IL-6) and gamma interferon (IFN-γ) was reduced at 24 h postchallenge, and the induction of tumor necrosis factor alpha (TNF-α) secretion, observed in the first hours postchallenge, was completely abolished at 24 h. Before challenge and at 12 h postchallenge, vaccinated mice displayed higher numbers of CD4
+
T, CD8
+
T, and B lymphocytes in the lungs. However, protection still occurs in the absence of each of these cells during the challenge, indicating that other effectors may be related to the prevention of lung injuries in this model. High levels of mucosal anti-PspA antibodies were maintained in vaccinated mice during the challenge, suggesting an important role in protection.
Human Papillomavirus (HPV) L1 and L1-L2 Virus-Like Particle-Based Multiplex Assays for Measurement of HPV Virion Antibodies
Authors: Hernandez Brenda Y. , Ton Thien , Shvetsov Yurii B. , Goodman Marc T. , Zhu Xuemei
Published: July 2012

Humoral immunity to human papillomavirus (HPV) has not been fully characterized, and there is currently no standard serologic test for the measurement of HPV antibodies. Most HPV serologic assays developed to date are based on virus-like particles (VLPs) of the major HPV capsid protein, L1. We sought to compare the performance of a multiplex HPV L1 VLP-based serologic assay to that of an assay based on VLPs comprised of both L1 and the minor capsid, L2. We developed HPV L1 VLP and L1-L2 VLP-based multiplex seroassays for the detection of HPV type 16 (HPV16) and HPV18 virion binding antibodies using Luminex fluorescent bead technology. We compared the performance of these assays to that of established pseudovirion-based neutralization and L1 VLP-based enzyme-linked immunosorbent assays (ELISAs).A total of 391 serum specimens from unvaccinated adult males and females were tested. The L1 and L1-L2 VLP multiplex seroassays each demonstrated substantial agreement with both the neutralization assays and the ELISAs for the detection of HPV16 antibodies (κ = 0.60 to 0.64). However, the L1-L2 VLP seroassay demonstrated better agreement with neutralization assays for the detection of HPV18 antibodies than the L1 VLP seroassay (κ = 0.74 and 0.43, respectively). L1 and L1-L2 VLP seroassays showed excellent agreement with one another for the detection of HPV16 antibodies (κ = 0.86) but only moderate agreement for HPV18 antibodies (κ = 0.44). The HPV L1-L2 VLP seroassay performs well for the concurrent measurement of HPV16 and -18 antibodies in large numbers of samples and may be extended to include other HPV types.
Impaired Function of Antibodies to Pneumococcal Surface Protein A but Not to Capsular Polysaccharide in Mexican American Adults with Type 2 Diabetes Mellitus
Authors: Mathews Christine E. , Brown Eric L. , Martinez Perla J. , Bagaria Upasana , Nahm Moon H. , Burton Robert L. , Fisher-Hoch Susan P. , McCormick Joseph B. , Mirza Shaper
Published: July 2012

The goal of the study was to determine baseline protective titers of antibodies toStreptococcus pneumoniaesurface protein A (PspA) and capsular polysaccharide in individuals with and individuals without type 2 diabetes mellitus. A total of 561 individuals (131 individuals with diabetes and 491 without) were screened for antibodies to PspA using a standard enzyme-linked immunosorbent assay (ELISA). A subset of participants with antibodies to PspA were retested using a WHO ELISA to determine titers of antibodies to capsular polysaccharide (CPS) (serotypes 4, 6B, 9V, 14, 18C, 19A, 19F, and 23F). Functional activity of antibodies was measured by assessing their ability to enhance complement (C3) deposition on pneumococci and promote killing of opsonized pneumococci. Titers of antibodies to protein antigens (PspA) were significantly lower in individuals with diabetes than controls without diabetes (P= 0.01), and antibodies showed a significantly reduced complement deposition ability (P= 0.02). Both antibody titers and complement deposition were negatively associated with hyperglycemia. Conversely, titers of antibodies to capsular polysaccharides were either comparable between the two groups or were significantly higher in individuals with diabetes, as was observed for CPS 14 (P= 0.05). The plasma specimens from individuals with diabetes also demonstrated a higher opsonophagocytic index against CPS serotype 14. Although we demonstrate comparable protective titers of antibodies to CPS in individuals with and individuals without diabetes, those with diabetes had lower PspA titers and poor opsonic activity strongly associated with hyperglycemia. These results suggest a link between diabetes and impairment of antibody response.
Immunostimulatory Effects of Recombinant Erysipelothrix rhusiopathiae Expressing Porcine Interleukin-18 in Mice and Pigs
Authors: Ogawa Yohsuke , Minagawa Yu , Shi Fang , Eguchi Masahiro , Muneta Yoshihiro , Shimoji Yoshihiro
Published: July 2012

Interleukin-18 (IL-18), which was originally called gamma interferon (IFN-γ)-inducing factor, has been shown to play an important role in innate and acquired immune responses. In this study, attenuatedErysipelothrix rhusiopathiaestrains were engineered to produce porcine IL-18 (poIL-18) and evaluated for their potential immunostimulatory effect in animals. Recombinant poIL-18 was successfully expressed in the recombinantE. rhusiopathiaestrains YS-1/IL-18 and KO/IL-18. The culture supernatant of YS-1/IL-18 was confirmed to induce IFN-γ production in murine splenocytesin vitro, and this production was inhibited by incubation with anti-poIL-18 monoclonal antibodies. Furthermore, more IFN-γ production was induced upon stimulation of splenocytes with concanavalin A for splenocytes from mice that were intraperitoneally inoculated with YS-1/IL-18 than for splenocytes from control mice inoculated with the parent strain YS-1. Peritoneal macrophages from mice preinoculated with YS-1/IL-18 exhibited enhanced phagocytosis ofSalmonella entericasubsp.entericaserovar Typhimurium compared with peritoneal macrophages from control mice preinoculated with YS-1. We also confirmed the immunostimulatory effect on humoral immune responses against antigens ofE. rhusiopathiaeandMycoplasma hyopneumoniaein gnotobiotic pigs that were orally preinoculated with KO/IL-18. Thus, these results provide evidence thatE. rhusiopathiaeis a promising vector for the expression of host cytokines and suggest the potential utility ofE. rhusiopathiaevector-encoded cytokines in the activation of host innate and acquired immune responses.
Oral and Airway Microbiota in HIV-Infected Pneumonia Patients
Authors: Iwai Shoko , Fei Matthew , Huang Delphine , Fong Serena , Subramanian Anuradha , Grieco Katherine , Lynch Susan V. , Huang Laurence
Published: July 2012

Despite the increased frequency of recurrent pneumonia in HIV-infected patients and recent studies linking the airway bacterial community (microbiota) to acute and chronic respiratory infection, little is known of the oral and airway microbiota that exist in these individuals and their propensity to harbor pathogens despite antimicrobial treatment for acute pneumonia. This pilot study compared paired samples of the oral and airway microbiota from 15 hospitalized HIV-infected patients receiving antimicrobial treatment for acute pneumonia. Total DNA was extracted, bacterial burden was assessed by quantitative PCR, and amplified 16S rRNA was profiled for microbiome composition using a phylogenetic microarray (16S rRNA PhyloChip). Though the bacterial burden of the airway was significantly lower than that of the oral cavity, microbiota in both niches were comparably diverse. However, oral and airway microbiota exhibited niche specificity. Oral microbiota were characterized by significantly increased relative abundance of multiple species associated with the mouth, including members of the
Bacteroides
,
Firmicutes
, and TM7 phyla, while airway microbiota were primarily characterized by a relative expansion of the
Proteobacteria
. Twenty-two taxa were detected in both niches, including
Streptococcus bovis
and
Chryseobacterium
species, pathogens associated with HIV-infected populations. In addition, we compared the airway microbiota of five of these patients to those of five non-HIV-infected pneumonia patients from a previous study. Compared to the control population, HIV-infected patients exhibited relative increased abundance of a large number of phylogenetically distinct taxa, which included several known or suspected pathogenic organisms, suggesting that recurrent pneumonia in HIV-infected populations may be related to the presence of these species.
Emergence of High-Level Mupirocin Resistance in Coagulase-Negative Staphylococci Associated with Increased Short-Term Mupirocin Use
Authors: Bathoorn Erik , Hetem David J. , Alphenaar Jeriela , Kusters Johannes G. , Bonten Marc J. M.
Published: July 2012

In our hospital, mupirocin has increasingly been used for peri-operative decolonization of
Staphylococcus aureus
. The target for mupirocin is isoleucyl tRNA synthetase (
ileS
). High-level resistance to mupirocin is conferred by acquisition of plasmids expressing a distinct
ileS
gene (
ileS2
). Here we evaluated the longitudinal trends in high-level mupirocin resistance in coagulase-negative staphylococci (CoNS) and linked this to the presence of
ileS2
genes and mupirocin use. We assessed mupirocin resistance in CoNS bloodstream isolates from 2006 to 2011 tested by Phoenix automated testing (PAT). We evaluated the reliability of PAT results using Etest. PAT species determination was confirmed by MALDI-TOF (matrix-assisted laser desorption ionization–time of flight) mass spectrometry. We investigated the presence of
ileS2
in the first 100 consecutive CoNS bloodstream isolates of each year using RT-PCR. Mupirocin use increased from 3.6 kg/year in 2006 to 13.3 kg/year in 2010 and correlated with the increase in the percentage of CoNS isolates carrying
ileS2
(8% in 2006 to 22% in 2011; Spearman's rho, 0.137;
P
= 0.01). The sensitivity and specificity of PAT for detecting high-level mupirocin resistance were 0.97 and 0.97, respectively.
ileS2
was detected in 81 of 82 phenotypically highly mupirocin-resistant strains and associated with resistance to ciprofloxacin, erythromycin, and clindamycin. In conclusion, we found a rapid increase in high-level resistance to mupirocin and resistance to other antibiotics in CoNS associated with an increase in mupirocin use. The associated resistance to other antibiotics may result in a reduction of oral antibiotic options for prolonged treatment of prosthetic infections with CoNS.
Evaluation of Two Novel Rapid rKE16 Antigen-Based Tests for Diagnosis of Visceral Leishmaniasis in India
Authors: Vaish Manisha , Sharma Smriti , Chakravarty Jaya , Sundar Shyam
Published: July 2012

We compared the two formats of rKE16 antigen-based rapid tests, a flowthrough test (KEFT) and a lateral flow test (KELF), with the rK39 rapid test for the diagnosis of visceral leishmaniasis. Sensitivities with KEFT (99%, 198/200) and rK39 (99.5%, 199/200) were comparable and higher than that with KELF (95.5%, 191/200). In the control groups comprising subjects with diseases from areas of nonendemicity or endemicity and subjects with different diseases, the specificities were comparable for all three rapid tests, except that specificity was higher with KELF in the controls from areas of endemicity.
Molecular Typing of Mycobacterium abscessus Based on Tandem-Repeat Polymorphism
Authors: Wong Y. L. , Ong C. S. , Ngeow Y. F.
Published: July 2012

A variable-number tandem-repeat (VNTR) typing assay for the differentiation of
Mycobacterium abscessus
strains was developed. This assay showed complete reproducibility, locus stability, and a discriminatory power (Hunter-Gaston discriminatory index [HGDI] of 0.9563) that is superior to that of multilocus sequencing. It is a promising tool for the investigation of
Mycobacterium abscessus
epidemiology and nosocomial outbreaks.
Multiple Lung Abscesses Caused by Actinomyces graevenitzii Mimicking Acute Pulmonary Coccidioidomycosis
Authors: Nagaoka Kentaro , Izumikawa Koichi , Yamamoto Yoshihiro , Yanagihara Katsunori , Ohkusu Kiyofumi , Kohno Shigeru
Published: July 2012

Actinomyces graevenitzii
is a newly recognized
Actinomyces
species that is seldom isolated from clinical specimens. A case of multiple pulmonary abscesses mimicking acute pulmonary coccidioidomycosis is described in this study, and the findings indicate that this organism is an opportunistic human pathogen.
Streptococcus tigurinus, a Novel Member of the Streptococcus mitis Group, Causes Invasive Infections
Authors: Zbinden Andrea , Mueller Nicolas J. , Tarr Philip E. , Eich Gerhard , Schulthess Bettina , Bahlmann Anna S. , Keller Peter M. , Bloemberg Guido V.
Published: July 2012

We recently described the novel speciesStreptococcus tigurinussp. nov. belonging to theStreptococcus mitisgroup. The type strain AZ_3aTofS. tigurinuswas originally isolated from a patient with infective endocarditis. According to its phenotypic and molecular characteristics,S. tigurinusis most closely related toStreptococcus mitis,Streptococcus pneumoniae,Streptococcus pseudopneumoniae,Streptococcus oralis, andStreptococcus infantis. Accurate identification ofS. tigurinusis facilitated by 16S rRNA gene analysis. We retrospectively analyzed our 16S rRNA gene molecular database, which contains sequences of all clinical samples obtained in our institute since 2003. We detected 17 16S rRNA gene sequences which were assigned toS. tigurinus, including sequences from the 3S. tigurinusstrains described previously.S. tigurinusoriginated from normally sterile body sites, such as blood, cerebrospinal fluid, or heart valves, of 14 patients and was initially detected by culture or broad-range 16S rRNA gene PCR, followed by sequencing. The 14 patients had serious invasive infections, i.e., infective endocarditis (n= 6), spondylodiscitis (n= 3), bacteremia (n= 2), meningitis (n= 1), prosthetic joint infection (n= 1), and thoracic empyema (n= 1). To evaluate the presence ofStreptococcus tigurinusin the endogenous oral microbial flora, we screened saliva specimens of 31 volunteers. After selective growth, alpha-hemolytic growing colonies were analyzed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and subsequent molecular methods.S. tigurinuswas not identified among 608 strains analyzed. These data indicate thatS. tigurinusis not widely distributed in the oral cavity. In conclusion,S. tigurinusis a novel agent of invasive infections, particularly infective endocarditis.
Rapid Detection of Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae
Authors: Nordmann Patrice , Dortet Laurent , Poirel Laurent
Published: July 2012

Enterobacterial strains producing clavulanic-acid-inhibited extended-spectrum β-lactamases (ESBLs) are increasingly reported worldwide. Conventional detection of ESBL production remains time-consuming (24 to 48 h). Therefore, the ESBL NDP (Nordmann/Dortet/Poirel) test was developed for a rapid identification of ESBLs in
Enterobacteriaceae
. This biochemical test was based on the
in vitro
detection of a cephalosporin (cefotaxime) hydrolysis that is inhibited by tazobactam addition. The ESBL activity was evidenced by a color change (red to yellow) of a pH indicator (red phenol) due to carboxyl-acid formation resulting from cefotaxime hydrolysis that was reversed by addition of tazobactam (positive test). The ESBL NDP test was applied to cultured strains (215 ESBL producers and 40 ESBL nonproducers). Its sensitivity and specificity were 92.6% and 100%, respectively. Its sensitivity (100%) was excellent for detection of CTX-M producers. A few ESBL producers (
n
= 16) that remained susceptible to cefotaxime were not detected. The test was also evaluated on spiked blood cultures and showed excellent sensitivity and specificity (100% for both). The test was rapid (less than 1 h) and cost-effective. It can be implemented in any health care facility and is well adapted for infection control purposes in particular.
Catheter-Related Bacteremia Caused by Multidrug-Resistant Leclercia adecarboxylata in a Patient with Breast Cancer
Authors: Shin Gee-Wook , You Myung-Jo , Lee Hye-Soo , Lee Chang-Seop
Published: July 2012

We report a multidrug-resistant strain of
Leclercia adecarboxylata
responsible for catheter-related bacteremia in a 47-year-old female with breast cancer. The isolated strain was resistant to several β-lactams, aminoglycosides, and folate pathway inhibitors and harbored

bla
TEM-1

and

bla
CTX-M

group 1 and
intl1
genes (
dfrA12-orfF-aadA2
) as genetic determinants for resistance. Based on a review of the
L. adecarboxylata
literature, there have been only 4 reports of antibiotic-resistant strains. To our knowledge, this is the first report of an
L. adecarboxylata
strain with simultaneous resistance to β-lactams, aminoglycosides, and sulfonamides.
Long-Term Hepatitis B Virus Surface Antigen Decay in HIV-1/Hepatitis B Virus-Coinfected Adults Initiating a Tenofovir-Containing Regimen
Authors: Tuaillon E. , Lozano C. , Kuster N. , Poinso A. , Kania D. , Nagot N. , Mondain A. M. , Pageaux G. P. , Ducos J. , Van de Perre P. , Reynes J.
Published: July 2012

Hepatitis B virus (HBV) surface antigen (HBsAg) decay was explored in HIV-1- and HBV-coinfected patients beginning antiretroviral (ARV) therapy containing tenofovir disoproxil fumarate (TDF). The mean HBsAg decay was 0.38 log
10
IU/ml/year (95% confidence interval [CI], 0.71 to 0.05) in 18 patients with sustained plasma HIV-1 RNA suppression and 0.15 log
10
IU/ml/year (0.21 to 0.09) in 12 patients experiencing HIV-1 virologic failure due to suboptimal adherence to ARV (
P
= 0.17). We estimated that six of these 18 patients will attain HBsAg values below 10 IU/ml after 10 years of treatment.
Formic Acid-Based Direct, On-Plate Testing of Yeast and Corynebacterium Species by Bruker Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Theel Elitza S. , Schmitt Bryan H. , Hall Leslie , Cunningham Scott A. , Walchak Robert C. , Patel Robin , Wengenack Nancy L.
Published: July 2012

An on-plate testing method using formic acid was evaluated on the Bruker Biotyper matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry system using 90 yeast and 78
Corynebacterium
species isolates, and 95.6 and 81.1% of yeast and 96.1 and 92.3% of
Corynebacterium
isolates were correctly identified to the genus and species levels, respectively. The on-plate method using formic acid yielded identification percentages similar to those for the conventional but more laborious tube-based extraction.
Recurrent Bacteremia Caused by the Acinetobacter calcoaceticus-Acinetobacter baumannii Complex
Authors: Lai Chih-Cheng , Hsu Han-Lin , Tan Che-Kim , Tsai Hsih-Yeh , Cheng Aristine , Liu Chia-Ying , Huang Yu-Tsung , Liao Chun-Hsing , Sheng Wang-Huei , Hsueh Po-Ren
Published: July 2012

This study investigated the clinical and microbiological characteristics of patients with recurrent bacteremia caused by the
Acinetobacter calcoaceticus-Acinetobacter baumannii
(ACB) complex at a medical center. All ACB complex isolates associated with recurrent bacteremia were identified to the genomic species level using a 16S-23S rRNA gene intergenic spacer sequence-based method. Genotypes were determined by the random amplified polymorphic DNA patterns generated by arbitrarily primed PCR and by pulsotypes generated by pulsed-field gel electrophoresis. Relapse of infection was defined as when the genotype of the recurrent isolate was identical to that of the original infecting strain. Reinfection was defined as when the genospecies or genotype of the recurrent isolate differed from that of the original isolate. From 2006 to 2008, 446 patients had ACB complex bacteremia and 25 (5.6%) had recurrent bacteremia caused by the ACB complex. Among the 25 patients, 12 (48%) had relapse of bacteremia caused by
A. nosocomialis
(
n
= 7) or
A. baumannii
(
n
= 5). Among the 13 patients with reinfection, 5 (38.5%) had reinfection caused by different genospecies of the ACB complex. Most of the patients were immunocompromised, and most of the infection foci were catheter-related bloodstream infections. The overall in-hospital mortality rate was 33.3%.
A. baumannii
isolates had lower antimicrobial susceptibility rates than
A. nosocomialis
and
A. pittii
isolates. In conclusion, relapse of ACB complex bacteremia can develop in immunocompromised patients, especially those with central venous catheters. Molecular methods to identify the ACB complex to the genospecies level are essential for differentiating between reinfection and relapse of bacteremia caused by the ACB complex.
Performance of the Abbott RealTime HCV Genotype II RUO Assay
Authors: Shinol Rebecca C. , Gale Howard B. , Kan Virginia L.
Published: July 2012

The Abbott RealTime HCV Genotype II RUO (research use only) assay was evaluated using the automated Abbott RealTime
m
2000 system. Concordance was 98% (81/83 samples) with samples previously typed by the Versant HCV Genotype 2.0 RUO system with manual extraction. The total assay time was reduced from 10.5 to 6.0 h and hands-on time from 13 to 4 min/patient sample.
Evaluation of a New Molecular Test, the BD Max Cdiff, for Detection of Toxigenic Clostridium difficile in Fecal Samples
Authors: Le Guern Rémi , Herwegh Stéphanie , Grandbastien Bruno , Courcol René , Wallet Frédéric
Published: July 2012

A new molecular assay detecting toxigenic
Clostridium difficile
, the BD Max Cdiff (Becton, Dickinson), was evaluated with 360 diarrheal feces samples. It exhibited high sensitivity (97.7%) and specificity (99.7%). The positive (97.7%) and negative (99.7%) predictive values of this test allow an accurate answer within 2 h.
Pleurostomophora ochracea, a Novel Agent of Human Eumycetoma with Yellow Grains
Authors: Mhmoud Najwa A. , Ahmed Sarah Abdalla , Fahal Ahmed H. , de Hoog G. Sybren , Gerrits van den Ende A. H. G. , van de Sande Wendy W. J.
Published: July 2012

The first yellow-grain fungal mycetoma, in a 60-year-old man from Central Sudan, is reported. Morphological and phylogenetic analysis of the ribosomal small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS), β-tubulin (
BT2
), actin (
ACT1
), and elongation factor (
TEF1
) genes revealed that the isolate deviated from any known agent of mycetoma; it clustered in the genus
Pleurostoma
(anamorph genus,
Pleurostomophora
) in the order
Calosphaeriales
. The novel species, here named
Pleurostomophora ochracea
, is characterized by phenotypic features. The species proved to be highly susceptible to itraconazole, ketoconazole, posaconazole, and voriconazole, but not to fluconazole. The fungus was inhibited by caspofungin at 8 μg/ml, while no inhibition was found with 5-flucytosine (MIC > 64 μg/ml). Compared to other members of the genus
Pleurostomophora
,
P. ochracea
is slow growing, with a relatively high optimum growth temperature (36 to 37°C). This is the first case of a yellow-grain fungal mycetoma; yellow grains are otherwise of bacterial nature. Our case emphasizes that identification of mycetoma agents by the color of the grain only is not sufficient and may lead to inappropriate therapy.
Comparison of Four Chromogenic Culture Media for Carbapenemase-Producing Enterobacteriaceae
Authors: Wilkinson Kathryn M. , Winstanley Trevor G. , Lanyon Clare , Cummings Stephen P. , Raza Muhammad W. , Perry John D.
Published: July 2012

Four chromogenic media for carbapenemase-producing
Enterobacteriaceae
(CPE) and two selective broths were challenged with a collection of
Enterobacteriaceae
with well-defined β-lactamases and 100 stool samples. With low inocula of 130 isolates of CPE, the sensitivities of the four chromogenic media were as follows: Brilliance CRE, 78%; chromID Carba, 91%; chromID ESBL, 96%; and Colorex KPC, 56%. The corresponding sensitivities of Trypticase soy broth plus ertapenem or meropenem were 78% and 47%, respectively.
Pangaea and the Out-of-Africa Model of Varicella-Zoster Virus Evolution and Phylogeography
Authors: Grose Charles
Published: July 2012

The goal of this minireview is to provide an overview of varicella-zoster virus (VZV) phylogenetics and phylogeography when placed in the broad context of geologic time. Planet Earth was formed over 4 billion years ago, and the supercontinent Pangaea coalesced around 400 million years ago (mya). Based on detailed tree-building models, the base of the phylogenetic tree of theHerpesviridaefamily has been estimated at 400 mya. Subsequently, Pangaea split into Laurasia and Gondwanaland; in turn, Africa rifted from Gondwanaland. Based on available data, the hypothesis of this minireview is that the ancestral alphaherpesvirus VZV coevolved in simians, apes, and hominins in Africa. When anatomically modern humans first crossed over the Red Sea 60,000 years ago, VZV was carried along in their dorsal root ganglia. Currently, there are five VZV clades, distinguishable by single nucleotide polymorphisms. These clades likely represent continued VZV coevolution, as humans with latent VZV infection left Arabia and dispersed into Asia (clades 2 and 5) and Europe (clades 1, 3, and 4). The prototype VZV sequence contains nearly 125,000 bp, divided into 70 open reading frames. Generally, isolates within a clade display >99.9% identity to one another, while members of one clade compared to a second clade show 99.8% identity to one another. Recently, four different VZV genotypes that do not segregate into the previously defined five clades have been identified, a result indicating a wider than anticipated diversity among newly collected VZV strains around the world.
Biological Roles and Functional Mechanisms of Arenavirus Z Protein in Viral Replication
Authors: Wang Jialong , Danzy Shamika , Kumar Naveen , Ly Hinh , Liang Yuying
Published: July 2012

Arenaviruses can cause severe hemorrhagic fever diseases in humans, with limited prophylactic or therapeutic measures. A small RING-domain viral protein Z has been shown to mediate the formation of virus-like particles and to inhibit viral RNA synthesis, although its biological roles in an infectious viral life cycle have not been directly addressed. By taking advantage of the available reverse genetics system for a model arenavirus, Pichinde virus (PICV), we provide the direct evidence for the essential biological roles of the Z protein's conserved residues, including the G2 myristylation site, the conserved C and H residues of RING domain, and the poorly characterized C-terminal L79 and P80 residues. Dicodon substitutions within the late (L) domain (
PS
A
PP
Y
EP
) of the PICV Z protein, although producing viable mutant viruses, have significantly reduced virus growth, a finding suggestive of an important role for the intact L domain in viral replication. Further structure-function analyses of both PICV and Lassa fever virus Z proteins suggest that arenavirus Z proteins have similar molecular mechanisms in mediating their multiple functions, with some interesting variations, such as the role of the G2 residue in blocking viral RNA synthesis. In summary, our studies have characterized the biological roles of the Z protein in an infectious arenavirus system and have shed important light on the distinct functions of its domains in virus budding and viral RNA regulation, the knowledge of which may lead to the development of novel antiviral drugs.
Measles Virus Transmission from Dendritic Cells to T Cells: Formation of Synapse-Like Interfaces Concentrating Viral and Cellular Components
Authors: Koethe Susanne , Avota Elita , Schneider-Schaulies Sibylle
Published: July 2012

Transmission of measles virus (MV) to T cells by its early CD150
+
target cells is considered to be crucial for viral dissemination within the hematopoietic compartment. Using cocultures involving monocyte-derived dendritic cells (DCs) and T cells, we now show that T cells acquire MV most efficiently from
cis
-infected DCs rather than DCs having trapped MV (
trans
-infection). Transmission involves interactions of the viral glycoprotein H with its receptor CD150 and is therefore more efficient to preactivated T cells. In addition to rare association with actin-rich filopodial structures, the formation of contact interfaces consistent with that of virological synapses (VS) was observed where viral proteins accumulated and CD150 was redistributed in an actin-dependent manner. In addition to these molecules, activated LFA-1, DC-SIGN, CD81, and phosphorylated ezrin-radixin-moesin proteins, which also mark the HIV VS, redistributed toward the MV VS. Most interestingly, moesin and substance P receptor, both implicated earlier in assisting MV entry or cell-to-cell transmission, also partitioned to the transmission structure. Altogether, the MV VS shares important similarities to the HIV VS in concentrating cellular components potentially regulating actin dynamics, conjugate stability, and membrane fusion as required for efficient entry of MV into target T cells.
Histone H3 Lysine 4 Methylation Marks Postreplicative Human Cytomegalovirus Chromatin
Authors: Nitzsche Alexandra , Steinhäußer Charlotte , Mücke Katrin , Paulus Christina , Nevels Michael
Published: July 2012

In the nuclei of permissive cells, human cytomegalovirus genomes form nucleosomal structures initially resembling heterochromatin but gradually switching to a euchromatin-like state. This switch is characterized by a decrease in histone H3 K9 methylation and a marked increase in H3 tail acetylation and H3 K4 methylation across the viral genome. We used ganciclovir and a mutant virus encoding a reversibly destabilized DNA polymerase to examine the impact of DNA replication on histone modification dynamics at the viral chromatin. The changes in H3 tail acetylation and H3 K9 methylation proceeded in a DNA replication-independent fashion. In contrast, the increase in H3 K4 methylation proved to depend widely on viral DNA synthesis. Consistently, labeling of nascent DNA using “click chemistry” revealed preferential incorporation of methylated H3 K4 into viral (but not cellular) chromatin during or following DNA replication. This study demonstrates largely selective epigenetic tagging of postreplicative human cytomegalovirus chromatin.
Potential Electrostatic Interactions in Multiple Regions Affect Human Metapneumovirus F-Mediated Membrane Fusion
Authors: Chang Andres , Hackett Brent A. , Winter Christine C. , Buchholz Ursula J. , Dutch Rebecca Ellis
Published: July 2012

The recently identified human metapneumovirus (HMPV) is a worldwide respiratory virus affecting all age groups and causing pneumonia and bronchiolitis in severe cases. Despite its clinical significance, no specific antiviral agents have been approved for treatment of HMPV infection. Unlike the case for most paramyxoviruses, the fusion proteins (F) of a number of strains, including the clinical isolate CAN97-83, can be triggered by low pH. We recently reported that residue H435 in the HRB linker domain acts as a pH sensor for HMPV CAN97-83 F, likely through electrostatic repulsion forces between a protonated H435 and its surrounding basic residues, K295, R396, and K438, at low pH. Through site-directed mutagenesis, we demonstrated that a positive charge at position 435 is required but not sufficient for F-mediated membrane fusion. Arginine or lysine substitution at position 435 resulted in a hyperfusogenic F protein, while replacement with aspartate or glutamate abolished fusion activity. Studies with recombinant viruses carrying mutations in this region confirmed its importance. Furthermore, a second region within the F2domain identified as being rich in charged residues was found to modulate fusion activity of HMPV F. Loss of charge at residues E51, D54, and E56 altered local folding and overall stability of the F protein, with dramatic consequences for fusion activity. As a whole, these studies implicate charged residues and potential electrostatic interactions in function, pH sensing, and overall stability of HMPV F.
A Ribosome-Binding, 3′ Translational Enhancer Has a T-Shaped Structure and Engages in a Long-Distance RNA-RNA Interaction
Authors: Gao Feng , Kasprzak Wojciech , Stupina Vera A. , Shapiro Bruce A. , Simon Anne E.
Published: July 2012

Many plant RNA viruses contain elements in their 3′ untranslated regions (3′ UTRs) that enhance translation. The PTE (
Panicum mosaic virus
-like translational enhancer) of
Pea enation mosaic virus
(PEMV) binds to eukaryotic initiation factor 4E (eIF4E), but how this affects translation from the 5′ end is unknown. We have discovered a three-way branched element just upstream of the PEMV PTE that engages in a long-distance kissing-loop interaction with a coding sequence hairpin that is critical for the translation of a reporter construct and the accumulation of the viral genome
in vivo
. Loss of the long-distance interaction was more detrimental than elimination of the adjacent PTE, indicating that the RNA-RNA interaction supports additional translation functions besides relocating the PTE to the 5′ end. The branched element is predicted by molecular modeling and molecular dynamics to form a T-shaped structure (TSS) similar to the ribosome-binding TSS of
Turnip crinkle virus
(TCV). The PEMV element binds to plant 80S ribosomes with a

K
d

(dissociation constant) of 0.52 μM and to 60S subunits with a

K
d

of 0.30 μM. Unlike the TCV TSS, the PEMV element also binds 40S subunits (

K
d

, 0.36 μM). Mutations in the element that suppressed translation reduced either ribosome binding or the RNA-RNA interaction, suggesting that ribosome binding is important for function. This novel, multifunctional element is designated a kl-TSS (kissing-loop T-shaped structure) to distinguish it from the TCV TSS. The kl-TSS has sequence and structural features conserved with the upper portion of most PTE-type elements, which, with the exception of the PEMV PTE, can engage in similar long-distance RNA-RNA interactions.
Stable Antigen Is Most Effective for Eliciting CD8+T-Cell Responses after DNA Vaccination and Infection with Recombinant Vaccinia VirusIn Vivo
Authors: Schliehe Christopher , Bitzer Annegret , van den Broek Maries , Groettrup Marcus
Published: July 2012

The induction of strong CD8+T-cell responses against infectious diseases and cancer has remained a major challenge. Depending on the source of antigen and the infectious agent, priming of CD8+T cells requires direct and/or cross-presentation of antigenic peptides on major histocompatibility complex (MHC) class I molecules by professional antigen-presenting cells (APCs). However, both pathways show distinct preferences concerning antigen stability. Whereas direct presentation was shown to efficiently present peptides derived from rapidly degraded proteins, cross-presentation is dependent on long-lived antigen species. In this report, we analyzed the role of antigen stability on DNA vaccination and recombinant vaccinia virus (VV) infection using altered versions of the same antigen. The long-lived nucleoprotein (NP) of lymphocytic choriomeningitis virus (LCMV) can be targeted for degradation by N-terminal fusion to ubiquitin or, as we show here, to the ubiquitin-like modifier FAT10. Direct presentation by cells either transfected with NP-encoding plasmids or infected with recombinant VVin vitrowas enhanced in the presence of short-lived antigens.In vivo, however, the highest induction of NP-specific CD8+T-cell responses was achieved in the presence of long-lived NP. Our experiments provide evidence that targeting antigens for proteasomal degradation does not improve the immunogenicity of DNA vaccines and recombinant VVs. Rather, it is the long-lived antigen that is superior for the efficient activation of MHC class I-restricted immune responsesin vivo. Hence, our results suggest a dominant role for antigen cross-priming in DNA vaccination and recombinant VV infection.
Nectin4 Is an Epithelial Cell Receptor for Canine Distemper Virus and Involved in Neurovirulence
Authors: Pratakpiriya Watanyoo , Seki Fumio , Otsuki Noriyuki , Sakai Kouji , Fukuhara Hideo , Katamoto Hiromu , Hirai Takuya , Maenaka Katsumi , Techangamsuwan Somporn , Lan Nguyen Thi , Takeda Makoto , Yamaguchi Ryoji
Published: July 2012

Canine distemper virus (CDV) uses signaling lymphocyte activation molecule (SLAM), expressed on immune cells, as a receptor. However, epithelial and neural cells are also affected by CDV
in vivo
. Wild-type CDV strains showed efficient replication with syncytia in Vero cells expressing dog nectin4, and the infection was blocked by an anti-nectin4 antibody. In dogs with distemper, CDV antigen was preferentially detected in nectin4-positive neurons and epithelial cells, suggesting that nectin4 is an epithelial cell receptor for CDV and also involved in its neurovirulence.
Peripheral Blood CD4 T-Cell and Plasmacytoid Dendritic Cell (pDC) Reactivity to Herpes Simplex Virus 2 and pDC Number Do Not Correlate with the Clinical or Virologic Severity of Recurrent Genital Herpes
Authors: Moss Nicholas J. , Magaret Amalia , Laing Kerry J. , Kask Angela Shaulov , Wang Minna , Mark Karen E. , Schiffer Joshua T. , Wald Anna , Koelle David M.
Published: July 2012

Leukocytes participate in the immune control of herpes simplex virus (HSV). Data from HIV coinfections, germ line mutations, and case reports suggest involvement of CD4 T cells and plasmacytoid dendritic cells (pDC). We investigated the relationships between these cells and recurrent genital herpes disease severity in the general population. Circulating CD4 T-cell responses to HSV-2 were measured in specimens from 67 immunocompetent individuals with measured genital lesion and HSV shedding rates. Similarly, pDC number and functional responses to HSV-2 were analyzed in 40 persons. CD4 responses and pDC concentrations and responses ranged as much as 100-fold between persons while displaying moderate within-person consistency over time. No correlations were observed between these immune response parameters and genital HSV-2 severity. Cytomegalovirus (CMV) coinfection was not correlated with differences in HSV-2-specific CD4 T-cell responses. The CD4 T-cell response to HSV-2 was much more polyfunctional than was the response to CMV. These data suggest that other immune cell subsets with alternate phenotypes or anatomical locations may be responsible for genital herpes control in chronically infected individuals.
Kaposi's Sarcoma-Associated Herpesvirus-Encoded LANA Recruits Topoisomerase IIβ for Latent DNA Replication of the Terminal Repeats
Authors: Purushothaman Pravinkumar , McDowell Maria E. , McGuinness James , Salas Ruth , Rumjahn Sharif M. , Verma Subhash C.
Published: July 2012

The latency-associated nuclear antigen (LANA) encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) plays a major role in maintaining latency and is critical for the perpetual segregation of viral episomes to the progeny nuclei of newly divided cells. LANA binds to KSHV terminal repeat (TR) DNA and tethers the viral episomes to host chromosomes through the association of chromatin-bound cellular proteins. TR elements serve as potential origin sites of KSHV replication and have been shown to play important roles in latent DNA replication and transcription of adjacent genes. Affinity chromatography and proteomics analysis using KSHV TR DNA and the LANA binding site as the affinity column identified topoisomerase IIβ (TopoIIβ) as a LANA-interacting protein. Here, we show that TopoIIβ forms complexes with LANA that colocalize as punctuate bodies in the nucleus of KSHV-infected cells. The specific TopoIIβ binding region of LANA has been identified to its N terminus and the first 32 amino acid residues containing the nucleosome-binding region crucial for binding. Moreover, this region could also act as a dominant negative to disrupt association of TopoIIβ with LANA. TopoIIβ plays an important role in LANA-dependent latent DNA replication, as addition of ellipticine, a selective inhibitor of TopoII, negatively regulated replication mediated by the TR. DNA break labeling and chromatin immunoprecipitation assay using biotin-16-dUTP and terminal deoxynucleotide transferase showed that TopoIIβ mediates a transient DNA break on viral DNA. These studies confirm that LANA recruits TopoIIβ at the origins of latent replication to unwind the DNA for replication.