bluuebunny/crossref_metadata_2025 huggingface dataset:
Shewanella putrefaciens mtrBEncodes an Outer Membrane Protein Required for Fe(III) and Mn(IV) Reduction
Authors: Beliaev Alexander S. , Saffarini Daad A.
Published: March 2020

Iron and manganese oxides or oxyhydroxides are abundant transition metals, and in aquatic environments they serve as terminal electron acceptors for a large number of bacterial species. The molecular mechanisms of anaerobic metal reduction, however, are not understood.Shewanella putrefaciensis a facultative anaerobe that uses Fe(III) and Mn(IV) as terminal electron acceptors during anaerobic respiration. Transposon mutagenesis was used to generate mutants ofS. putrefaciens, and one such mutant, SR-21, was analyzed in detail. Growth and enzyme assays indicated that the mutation in SR-21 resulted in loss of Fe(III) and Mn(IV) reduction but did not affect its ability to reduce other electron acceptors used by the wild type. This deficiency was due to Tn5inactivation of an open reading frame (ORF) designatedmtrB. mtrBencodes a protein of 679 amino acids and contains a signal sequence characteristic of secreted proteins. Analysis of membrane fractions of the mutant, SR-21, and wild-type cells indicated that MtrB is located on the outer membrane ofS. putrefaciens. A 5.2-kb DNA fragment that containsmtrBwas isolated and completely sequenced. A second ORF, designatedmtrA, was found directly upstream ofmtrB. The two ORFs appear to be arranged in an operon.mtrAencodes a putative 10-hemec-type cytochrome of 333 amino acids. The N-terminal sequence of MtrA contains a potential signal sequence for secretion across the cell membrane. The amino acid sequence of MtrA exhibited 34% identity to NrfB fromEscherichia coli, which is involved in formate-dependent nitrite reduction. To our knowledge, this is the first report of genes encoding proteins involved in metal reduction.
Mutational Analysis of the
Rhizobium etli recA
Operator
Authors: Tapias Angels , Barbé Jordi
Published: March 2020

Based upon our earlier studies (A. Tapias, A. R. Fernández de Henestrosa, and J. Barbé, J. Bacteriol. 179:1573–1579, 1997) we hypothesized that the regulatory sequence of the
Rhizobium etli recA
gene was TTGN
11
CAA. However, further detailed analysis of the
R. etli recA
operator described in the present work suggests that it may in fact be GAACN
7
GTAC. This new conclusion is based upon PCR mutagenesis analysis carried out in the
R. etli recA
operator, which indicates that the GAAC and GTAC submotifs found in the sequence GAACN
7
GTAC are required for the maximal stimulation of in vivo transcription and in vitro DNA-protein complex formation. This DNA-protein complex is also detected when the GAACN
7
GTAC wild-type sequence is modified to obtain GAACN
7
GAAC, GTACN
7
GTAC, or GAACN
7
GTTC. The wild-type promoters of the
Rhizobium meliloti
and
Agrobacterium tumefaciens recA
genes, which also contain the GAACN
7
GTAC sequence, compete with the
R. etli recA
promoter for the DNA-protein complex formation but not with mutant derivatives in any of these motifs, indicating that the
R. etli
,
R. meliloti
, and
A. tumefaciens recA
genes present the same regulatory sequence.
Aspartate Transcarbamylase from the Hyperthermophilic Eubacterium
Thermotoga maritima
: Fused Catalytic and Regulatory Polypeptides Form an Allosteric Enzyme
Authors: Chen Pingguo , Van Vliet Françoise , Van De Casteele Mark , Legrain Christianne , Cunin Raymond , Glansdorff Nicolas
Published: March 2020

In the allosteric aspartate transcarbamylase (ATCase) from the hyperthermophilic eubacterium
Thermotoga maritima
, the catalytic and regulatory functions, which in class B ATCases are carried out by specialized polypeptides, are combined on a single type of polypeptide assembled in trimers. The ATCases from
T. maritima
and
Treponema denticola
present intriguing similarities, suggesting horizontal gene transfer.
Molecular Analysis of a Gene Encoding a Cell-Bound Esterase from
Streptomyces chrysomallus
Authors: Berger Rico , Hoffmann Matthias , Keller Ullrich
Published: March 2020

A gene (
estA
) encoding a 42-kDa cell-bound esterase, EstA, was found to be located 75 bp upstream of the cyclophilin A gene (
cypA
) of
Streptomyces chrysomallus
. Western blot analysis revealed the presence of EstA (42 kDa) in cell extracts of
S. chrysomallus
X2 and
Streptomyces lividans
. EstA specifically hydrolyzes short-chain
p
-nitrophenyl esters. EstA formation starts at the end of growth phase, and its activity level remains constant throughout stationary phase. Expression of
estA
from the melanin (
mel
) promoter in plasmid pIJ702 led to a substantial increase of total esterase activity in streptomycetes.
Role of C-Terminal Domains in Surface Attachment of the Fructosyltransferase of
Streptococcus salivarius
ATCC 25975
Authors: Rathsam Catherine , Jacques Nicholas A.
Published: March 2020

The cell-associated β-
d
-fructosyltransferase of
Streptococcus salivarius
, which is devoid of the cell wall anchoring motif, LPXTG, is released on exposure to its substrate, sucrose. Deletions within the C terminus of the enzyme implicated both the hydrophobic and the proline-glycine-serine-threonine-rich wall-associated domain in stabilizing the enzyme on the cell surface.
PRS5, the Fifth Member of the Phosphoribosyl Pyrophosphate Synthetase Gene Family inSaccharomyces cerevisiae, Is Essential for Cell Viability in the Absence of eitherPRS1orPRS3
Authors: Hernando Yolanda , Parr Adrian , Schweizer Michael
Published: March 2020

InSaccharomyces cerevisiae, an open reading frame, YOL061w, encodes a polypeptide with sequence similarity to the four known 5-phosphoribosyl-1(α)-pyrophosphate synthetase (PRS) genes since it contains a divalent cation binding site and a phosphoribosyl pyrophosphate binding site. We regard YOL061w as the fifth member of thePRSgene family,PRS5. Loss of Prs5p has a significant impact on PRS enzyme activity, causing it to be reduced by 84%. On the other hand, Δprs5strains are not affected in growth or in the size of their nucleotide pools. However, simultaneous deletion ofPRS1andPRS5orPRS3andPRS5rendered the strains inviable, which implies thatPRS5plays an important role in the maintenance of PRS function inS. cerevisiae.
Role of the C Terminus of FtsK in
Escherichia coli
Chromosome Segregation
Authors: Yu Xuan-Chuan , Weihe Elizabeth K. , Margolin William
Published: March 2020

FtsK is essential for
Escherichia coli
cell division. We report that cells lacking the C terminus of FtsK are defective in chromosome segregation as well as septation, often exhibiting asymmetrically positioned nucleoids and large anucleate regions. Combining the corresponding truncated
ftsK
gene with a
mukB
null mutation resulted in a synthetic lethal phenotype. When the truncated
ftsK
was combined with a
minCDE
deletion, chains of minicells were generated, many of which contained DNA. These results suggest that the C terminus of FtsK has an important role in chromosome partitioning.
Rapid Detection of
mecA
-Positive and
mecA
-Negative Coagulase-Negative Staphylococci by an Anti-Penicillin Binding Protein 2a Slide Latex Agglutination Test
Authors: Hussain Zafar , Stoakes Luba , Garrow Shaunalee , Longo Susan , Fitzgerald Viivi , Lannigan Robert
Published: March 2020

A rapid slide latex agglutination (LA) test, MRSA-Screen (Denka Seiken Co., Niigata, Japan), which detects PBP 2a, was tested for its ability to differentiate between
mecA
-positive and -negative coagulase-negative staphylococci. A total of 463 isolates from 13 species were included in the study. The
mecA
gene was detected by PCR, and the oxacillin MIC was determined by the agar dilution method according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). The LA test was performed with oxacillin-induced isolates. The true-positive and true-negative results were defined on the basis of the presence or the absence of the
mecA
gene. By PCR, 251 isolates were
mecA
positive and 212 were
mecA
negative. The sensitivities, specificities, and positive and negative predictive values for the LA test compared to the NCCLS breakpoint for oxacillin resistance (≥0.5 mg/liter) were as follows: for the LA test, 100, 99.5, 99.6, and 100%, respectively; for the NCCLS breakpoint, 100, 60.8, 75.1, and 100%, respectively. One hundred twenty-five
mecA
-positive isolates were also tested by the LA test without induction of PBP 2a; only 72 (57.6%) gave a positive result and required 3 to 15 min for reaction. With induction, all 251 isolates were positive within 3 min. The LA test was reliable in classifying
mecA
-negative isolates, but it classified isolates for which the oxacillin MIC was ≥0.5 mg/liter as oxacillin susceptible. For the reliable detection of oxacillin resistance by the MRSA-Screen in coagulase-negative staphylococci, induction of the
mecA
gene appears to be necessary.
A Multicenter Study Evaluation of the Digene Hybrid Capture II Signal Amplification Technique for Detection of Hepatitis B Virus DNA in Serum Samples and Testing of EUROHEP Standards
Authors: Niesters Hubert G. M. , Krajden Mel , Cork Lynda , de Medina Maria , Hill Mary , Fries Edwin , Osterhaus Albert D. M. E.
Published: March 2020

We have evaluated the new Digene Hybrid Capture II HBV DNA Test (HCII HBV), which is a 96-well microtiter plate-based signal amplification assay. This test uses hybrid capture technology that specifically detects RNA-DNA hybrids. HCII HBV is able to quantify hepatitis B virus (HBV) DNA at between 1.4 × 10
5
and 1.7 × 10
9
HBV copies per ml in a standard format. By using a modified sample preparation method, which allows the input of 30-fold more serum for an ultrasensitive format, the sensitivity of the assay can be increased reproducibly to approximately 8,000 copies of HBV per ml. By using a combination of these two formats, the assay can quantify over a total range of 6 logs. In our multicenter evaluation study, the mean laboratory-to-laboratory coefficients of variation were 22, 7, and 12% at the three sites, respectively, with a combined specificity of 98.4%. The linearities of both the standard test and the ultrasensitive test were excellent, with Spearman correlation coefficients of 0.997 and 0.999, respectively. Furthermore, the intra-assay reproducibility for the standard assay gave coefficients of variation of from 13 to 33, 9 to 21, and 3 to 8% at the three sites, respectively. HCII HBV was shown to be genotype independent when the EUROHEP standards for genotypes A and D were used. This assay allows the accurate measurement of HBV DNA levels in serum and can be clinically used for the monitoring of responses to antiviral agents for patients chronically infected with HBV.
A Filamentous Phage Associated with Recent Pandemic
Vibrio parahaemolyticus
O3:K6 Strains
Authors: Nasu Hatsumi , Iida Tetsuya , Sugahara Tomomi , Yamaichi Yoshiharu , Park Kwon-Sam , Yokoyama Katsushi , Makino Kozo , Shinagawa Hideo , Honda Takeshi
Published: March 2020

A specific serotype, O3:K6, of
Vibrio parahaemolyticus
has recently been causing epidemics of gastroenteritis in Southeast Asia, Japan, and North America. To examine whether the new O3:K6 strains possess characteristics that may exacerbate outbreaks, we compared
V. parahaemolyticus
O3:K6 strains with non-O3:K6 strains using strains isolated from individuals with traveler's diarrhea at Kansai Airport Quarantine Station, Osaka, Japan. All 24 O3:K6 strains possessed a common plasmid, pO3K6 (DNA size, 8,782 bp, with 10 open reading frames [ORFs]). The gene organization of pO3K6 was similar to that of Vf33, a filamentous phage previously described in
V. parahaemolyticus
. We isolated a phage (phage f237) from the culture supernatant of
V. parahaemolyticus
O3:K6 strain KXV237, which formed a turbid plaque on an indicator strain. The genome of f237 was single-stranded DNA, and the double-stranded DNA obtained by treatment of the genome with DNA polymerase was identical to that of pO3K6 when analyzed by agarose gel electrophoresis after
Hin
dIII digestion. Furthermore, the N-terminal amino acid sequence of the f237 major coat protein was found in ORF4 of pO3K6. Our results showed that pO3K6 is a replicative form of f237. Among the ORFs found in the f237 genome, the sequence of ORF8 had no significant homology to those of any proteins in databases. ORF8 was located on a region corresponding to the distinctive region of Vf33, and its G+C content was apparently lower than that of the remaining DNA sequence of f237. By colony hybridization, ORF8 was detected only in O3:K6 strains isolated since 1996 and was not found in O3:K6 strains isolated before 1996 and clinical
V. parahaemolyticus
strains other than those of serotype O3:K6. Thus, this study shows that f237 is exclusively associated with recent
V. parahaemolyticus
O3:K6 strains. The ORF8 gene can be a useful genetic marker for the identification of the recently widespread O3:K6 strains of
V. parahaemolyticus
.
Cloning, Characterization, and Expression of a 200-Kilodalton Diagnostic Antigen of
Babesia bigemina
Authors: Tebele N. , Skilton R. A. , Katende J. , Wells C. W. , Nene V. , McElwain T. , Morzaria S. P. , Musoke A. J.
Published: March 2020

Current serological tests for
Babesia bigemina
use semipurified merozoite antigens derived from infected erythrocytes. One of the major drawbacks of these tests is that antigen quality can vary from batch to batch. Since the quality of the antigen contributes to the sensitivity and specificity of serological tests, the use of standardized recombinant antigens should ensure consistency in assay quality. Previously, a 200-kDa merozoite antigen (p200) was identified as a candidate diagnostic antigen for use in a serological assay for the detection of
B. bigemina
antibodies in infected cattle. In this study, we have cloned, characterized, and expressed p200. A 3.5-kbp cDNA clone encoding p200 was isolated and shown to be almost full length, lacking approximately 300 bp at the 5′ end. The predicted amino acid sequence shows that p200 consists of a long, highly charged central repeat region of an uninterrupted α helix, indicative of a fibrous protein. Immunoelectron microscopy localized p200 to the merozoite cytoplasm, suggesting that the antigen may be a structural protein involved in forming filament structures within the cytoskeleton. The 3.5-kbp cDNA was expressed in bacteria as a fusion protein with glutathione
S
-transferase (GST), but the yield was poor. To improve the yield, cDNA fragments encoding antigenic domains of p200 were expressed as fusions with GST. One of these fusion proteins, C1A-GST, is composed of a 7-kDa fragment of the p200 repeat region and contains epitopes that react strongly with sera from cattle experimentally infected with
B. bigemina
. Recombinant C1A-GST should permit the development of an improved enzyme-linked immunosorbent assay for the detection of antibodies against
B. bigemina.
Development of Antigen Detection Assay for Diagnosis of Tuberculosis Using Sputum Samples
Authors: Pereira Arias-Bouda Lenka M. , Nguyen Lan N. , Ho Ly M. , Kuijper Sjoukje , Jansen Henk M. , Kolk Arend H. J.
Published: March 2020

The rising incidence of tuberculosis worldwide means an increasing burden on diagnostic facilities, so tests simpler than Ziehl-Neelsen staining are needed. Such tests should be objective, reproducible, and have at least as good a detection limit as 10
4
bacteria/ml. A capture enzyme-linked immunosorbent assay (ELISA) was developed for detection of lipoarabinomannan (LAM) in human sputum samples. As a capture antibody, we used a murine monoclonal antibody against LAM, with rabbit antiserum against
Mycobacterium tuberculosis
as a source of detector antibodies. The sensitivity of the capture ELISA was evaluated by using purified LAM and
M. tuberculosis
whole cells. We were able to detect 1 ng of purified LAM/ml and 10
4
M. tuberculosis
whole cells/ml. LAM could also be detected in culture filtrate of a 3-week-old culture of
M. tuberculosis
. The culture filtrate contained approximately 100 μg of LAM/ml. The detection limit in sputum pretreated with
N
-acetyl-
l
-cysteine and proteinase K was 10
4
M. tuberculosis
whole cells per ml. Thirty-one (91%) of 34 sputum samples from 18 Vietnamese patients with tuberculosis (32 smear positive and 2 smear negative) were positive in the LAM detection assay. In contrast, none of the 25 sputum samples from 21 nontuberculous patients was positive. This specific and sensitive assay for the detection of LAM in sputum is potentially useful for the diagnosis of tuberculosis.
Intestinal Lesions Associated with Disseminated Candidiasis in an Experimental Animal Model
Authors: Andrutis Karl A. , Riggle Perry J. , Kumamoto Carol A. , Tzipori Saul
Published: March 2020

In human patients, disseminated candidiasis, a life-threatening disease for immunocompromised patients, is often associated with intestinal lesions. In this study, we demonstrate that immunosuppressed gnotobiotic (IGB) piglets orally inoculated with wild-type
Candida albicans
developed extensive intestinal lesions and disseminated infection. Severe ulceration of the ileal mucosa was observed overlying regions of colonization and necrosis of the gut-associated lymphoid tissue. Despite the high susceptibility of IGB piglets to many microbial pathogens, an avirulent mutant strain of
C. albicans
failed to produce intestinal lesions and exhibited poor dissemination, demonstrating that these effects required virulent organisms. It is likely that in IGB piglets, as in human patients, intestinal lesions provide the mechanism for escape of
C. albicans
from the gastrointestinal tract. Multinucleated giant cells containing fungal organisms were observed within lymph nodes and lymphatic vessels, and as with other pathogens, such cells could provide a mechanism for dissemination of
C. albicans
.
Diagnostic Potential of Puumala Virus Nucleocapsid Protein Expressed in
Drosophila melanogaster
Cells
Authors: Brus Sjölander Katarina , Golovljova Irina , Plyusnin Alexander , Lundkvist Åke
Published: March 2020

Puumala virus (PUU) nucleocapsid protein (N) was expressed in insect cells by using the Drosophila Expression System (DES; Invitrogen BV, Groningen, The Netherlands). Stable transfectants were established by hygromycin B selection and showed continuous expression of the recombinant protein (DES-PUU-N) for at least 5 months. The antigenic property of DES-PUU-N was shown to be identical to that of native PUU N when examined with a panel of hantavirus-specific monoclonal antibodies. Enzyme-linked immunosorbent assays (ELISAs) for detection of human immunoglobulin M (IgM) and IgG antibodies were established by using DES-PUU-N as antigen and were compared to assays based on native N. The ELISAs were evaluated for patient diagnosis and seroepidemiological purposes with panels of sera collected from patients with hemorrhagic fever with renal syndrome (HFRS) and from healthy blood donors. Equally high sensitivities and specificities for detection of PUU-specific IgM in acute-phase HFRS patient sera were obtained by the ELISA based on DES-PUU-N and the assay based on the native antigen. For detection of PUU-specific IgG, the ELISA based on monoclonal antibody-captured DES-PUU-N antigen showed optimal sensitivity and specificity.
Diagnosis of Invasive Amebiasis by Enzyme-Linked Immunosorbent Assay of Saliva To Detect Amebic Lectin Antigen and Anti-Lectin Immunoglobulin G Antibodies
Authors: Abd-Alla Mohamed D. , Jackson Terry F. H. G. , Reddy Selvan , Ravdin Jonathan I.
Published: March 2020

Saliva from subjects with amebic liver abscess (ALA), acute amebic colitis, asymptomatic infection with
Entamoeba histolytica
or
Entamoeba dispar
, and uninfected controls was tested by enzyme-linked immunosorbent assay (ELISA) for the presence of
E. histolytica
galactose-inhibitable lectin antigen and salivary immunoglobulin (IgG) antibodies to a recombinant cysteine-rich lectin-derived protein (LC3). Salivary lectin antigen was found in 65.8% of subjects with acute colitis, compared to 22.2% of those convalescent from ALA, 10.0% with asymptomatic
E. histolytica
infection, 9.8% with
E. dispar
infection, and 2.6% of controls (subjects from the United States and study patients with nonamebic diarrhea) (
P
< 0.001 for each compared to values for subjects with colitis). Salivary anti-LC3 IgG antibodies were found in 92% of ALA patients regardless of duration of illness and in 83.3% of colitis patients who were symptomatic for at least 7 days (
P
< 0.001 compared to other study groups). Serum anti-LC3 IgG antibodies were detected in 56.3% of subjects with acute colitis, 100% of subjects with ALA or prolonged colitis, 45% of subjects with asymptomatic
E. histolytica
infection, 32.3% of subjects with
E. dispar
infection, and 23.4% of diarrhea controls. In comparison to ELISA for serum anti-LC3 IgG antibodies, the salivary lectin antigen assay is a more sensitive and specific test for acute amebic colitis. Detection of salivary anti-LC3 IgG antibodies by ELISA is an effective means for the diagnosis of ALA and prolonged cases of amebic colitis.
Quantitative Real-Time PCR for
Porphyromonas gingivalis
and Total Bacteria
Authors: Lyons Sharon R. , Griffen Ann L. , Leys Eugene J.
Published: March 2020

Accurate quantitation of the number of cells of individual bacterial species in dental plaque samples is needed for understanding the bacterial etiology of periodontitis. Real-time PCR offers a sensitive, efficient, and reliable approach to quantitation. Using the TaqMan system we were able to determine both the amount of
Porphyromonas gingivalis
and the total number of bacterial cells present in plaque samples. Using species-specific primers and a fluorescent probe, detection of DNA from serial dilutions of
P. gingivalis
cells was linear over a large range of DNA concentrations (correlation coefficient = 0.96). No difference was observed between
P. gingivalis
DNA alone and the same DNA mixed with DNA isolated from dental plaque, indicating that
P. gingivalis
levels can be determined accurately from clinical samples. The total number of cells of all bacterial species was determined using universal primers and a fluorescent probe. Standard curves using four different bacterial species gave similar results (correlation coefficient = 0.86). Levels of both
P. gingivalis
and total bacteria were determined from a series of human plaque samples. High levels of
P. gingivalis
were observed in several of the samples from subjects with periodontitis and none of those from healthy subjects. Real-time quantitative PCR provided a sensitive and reliable method for quantitating
P. gingivalis
. In addition, it allowed the determination of the total number of bacterial cells present in a complex sample so that the percentage of
P. gingivalis
cells could be determined.
Isolation of
Acanthamoeba
-Specific Antibodies from a Bacteriophage Display Library
Authors: Khan Naveed A. , Greenman John , Topping Katherine P. , Hough Victoria C. , Temple Graham S. , Paget Timothy A.
Published: March 2020

Acanthamoeba
causes opportunistic eye infections in humans, which can lead to severe keratitis and may ultimately result in blindness. Current methods for identifying this organism rely on culture and microscopy. In this paper, we describe the isolation of antibody fragments that can be used for the unequivocal identification of
Acanthamoeba
. A bacteriophage antibody display library was used to isolate antibody fragments that bind specifically to
Acanthamoeba
. Individual clones were studied by enzyme-linked immunosorbent assay, flow cytometry, and immunofluorescence. Four antibody clones that specifically bind to
Acanthamoeba
spp. were identified.
Epidemiology of Recurrences or Reinfections of
Clostridium difficile
-Associated Diarrhea
Authors: Barbut Frédéric , Richard Anne , Hamadi Kheira , Chomette Valérie , Burghoffer Béatrice , Petit Jean-Claude
Published: March 2020

Approximately 15 to 35% of patients with a first episode of
Clostridium difficile
-associated diarrhea relapse within 2 months. Between 1994 and 1997, strains from 93 hospitalized patients with
C. difficile
recurrences were fingerprinted by using both serotyping and PCR-ribotyping. The results showed that 48.4% of clinical recurrences were, in fact, reinfections with a different strain of
C. difficile
. Rates of clinical recurrences could therefore be reduced by implementing strict isolation precautions.
Molecular Characterization of the
vanD
Gene Cluster and a Novel Insertion Element in a Vancomycin-Resistant Enterococcus Isolated in Canada
Authors: Boyd D. A. , Conly J. , Dedier H. , Peters G. , Robertson L. , Slater E. , Mulvey M. R.
Published: March 2020

A single
vanD
-containing
Enterococcus faecium
strain (N97-330) was isolated in Canada. The
vanD
-containing region was cloned and sequenced. Although the proteins have more than 96% identity to a previously described
vanD
region in BM4339, the

vanS
D

gene contains a frameshift mutation that leads to a predicted truncated protein. Furthermore, sequence analysis of the
ddl
gene revealed the presence of an IS
982
-like element (IS
Efm1
) which interrupted the
d
-Ala–
d
-Ala ligase. This suggested the constitutive expression of the
vanD
operon, which was confirmed. Pulsed-field gel electrophoresis fingerprinting demonstrated that BM4339 was not related to N97-330 (>15 band differences). Both strains contained multiple copies of the IS
982
-like element.
Survival of the Human Granulocytic Ehrlichiosis Agent under Refrigeration Conditions
Authors: Kalantarpour Fatemeh , Chowdhury Ishraq , Wormser Gary P. , Aguero-Rosenfeld Maria E.
Published: March 2020

The human granulocytic ehrlichiosis (HGE) agent in infected blood specimens remained viable during refrigeration at 4°C for up to 18 days. These findings suggest that blood specimens submitted for culture may withstand transportation to a remote laboratory. HGE should be added to the list of infections potentially transmitted by blood transfusion.
High Prevalence of TT Virus DNA in Human Saliva and Semen
Authors: Inami Tomoko , Konomi Nami , Arakawa Yasuyuki , Abe Kenji
Published: March 2020

Using the PCR assay, we found a high prevalence of TT virus (TTV) DNA in saliva and semen from patients who were seropositive for TTV. This finding suggests that the presence of TTV in body fluids other than serum may affect the routes of viral transmission.
Genetic Similarity among One
Aspergillus flavus
Strain Isolated from a Patient Who Underwent Heart Surgery and Two Environmental Strains Obtained from the Operating Room
Authors: Diaz-Guerra Teresa M. , Mellado Emilia , Cuenca-Estrella Manuel , Gaztelurrutia Lourdes , Navarro Jose Ignacio Villate , Tudela Juan L. Rodríguez
Published: March 2020

We report the simultaneous isolation of one
Aspergillus flavus
strain from the aortic prosthesis of a heart surgery patient and another two isolates recovered from a dual-reservoir cooler-heater used in the operating room where this patient was operated on. Genetic typing of these three isolates by randomly amplified polymorphic DNA (RAPD) revealed identical genotypes. Eight unrelated control strains of
A. flavus
had eight different genotypes. These results clearly indicated the nosocomial origin of the
A. flavus
strain isolated from the patient. We suggest that the RAPD technique is a rapid and reliable tool to ascertain the epidemiology of infections caused by
A. flavus
.
Comparison of Quantitations of Viral Load in Varicella and Zoster
Authors: Kimura Hiroshi , Kido Shinji , Ozaki Takao , Tanaka Naoko , Ito Yoshinori , Williams Richard K. , Morishima Tsuneo
Published: March 2020

The pathogenesis of varicella and zoster and the effects of antiviral treatment were investigated using real-time PCR for varicella-zoster virus (VZV) DNA in skin lesions and peripheral blood. A higher occurrence of viremic VZV DNA was observed in varicella than in zoster. Acyclovir treatment resulted in marked suppression of viremia in varicella.
Barrier-to-Autointegration Factor 1 Protects against a Basal cGAS-STING Response
Authors: Ma Hongming , Qian Wei , Bambouskova Monika , Collins Patrick L. , Porter Sofia I. , Byrum Andrea K. , Zhang Rong , Artyomov Maxim , Oltz Eugene M. , Mosammaparast Nima , Miner Jonathan J. , Diamond Michael S.
Published: March 2020

Although the interferon (IFN) signaling pathway is a key host mechanism to restrict infection of a diverse range of viral pathogens, its unrestrained activity either at baseline or in the context of an immune response can result in host cell damage and injury. Here, we used a genome-wide CRISPR-Cas9 screen and identified the DNA binding protein Barrier-to-autointegration factor 1 (Banf1) as a modulator of basal cell-intrinsic immunity. A loss of Banf1 expression resulted in higher level of cytosolic double-stranded DNA at baseline, which triggered IFN-stimulated gene expression via a cGAS-STING-IRF3 axis that did not require type I IFN or STAT1 signaling. Our experiments define a regulatory network in which Banf1 limits basal inflammation by preventing self DNA accumulation in the cytosol.
RNA Binding Motif Protein RBM45 Regulates Expression of the 11-Kilodalton Protein of Parvovirus B19 through Binding to Novel Intron Splicing Enhancers
Authors: Wang Jianke , Ganaie Safder S. , Cheng Fang , Xu Peng , Ning Kang , Wang Xiaomei , Kleiboeker Steve , Cheng Shipeng , Qiu Jianming
Published: March 2020

Human parvovirus B19 (B19V) is a human pathogen that causes severe hematological disorders in immunocompromised individuals. B19V infection has a remarkable tropism with respect to human erythroid progenitor cells (EPCs) in human bone marrow and fetal liver. During B19V infection, only one viral precursor mRNA (pre-mRNA) is transcribed by a single promoter of the viral genome and is alternatively spliced and alternatively polyadenylated, a process which plays a key role in expression of viral proteins. Our studies revealed that a cellular RNA binding protein, RBM45, binds to two intron splicing enhancers and is essential for the maturation of the small nonstructural protein 11-kDa-encoding mRNA. The 11-kDa protein plays an important role not only in B19V infection-induced apoptosis but also in viral DNA replication. Thus, the identification of the RBM45 protein and its cognate binding site in B19V pre-mRNA provides a novel target for antiviral development to combat B19V infection-caused severe hematological disorders.
The Multifunctional Long-Distance Movement Protein of
Pea Enation Mosaic Virus 2
Protects Viral and Host Transcripts from Nonsense-Mediated Decay
Authors: May Jared P. , Johnson Philip Z. , Ilyas Muhammad , Gao Feng , Simon Anne E.
Published: March 2020

Nonsense-mediated decay (NMD) represents an RNA regulatory pathway that degrades both natural and faulty messenger RNAs with long 3′ untranslated regions. NMD targets diverse families of RNA viruses, requiring that viruses counteract the NMD pathway for successful amplification in host cells. A protein required for long-distance movement of
Pea enation mosaic virus 2
(PEMV2) is shown to also protect both viral and host mRNAs from NMD. RNA-seq analyses of the
Nicotiana benthamiana
transcriptome revealed that PEMV2 infection significantly impairs the host NMD pathway. RNA viruses routinely induce large-scale changes in host gene expression, and, like PEMV2, may use NMD inhibition to alter the host transcriptome in an effort to increase virus amplification.
A Sustained Immune Response Supports Long-Term Antiviral Immune Priming in the Pacific Oyster, Crassostrea gigas
Authors: Lafont Maxime , Vergnes Agnès , Vidal-Dupiol Jeremie , de Lorgeril Julien , Gueguen Yannick , Haffner Philippe , Petton Bruno , Chaparro Cristian , Barrachina Celia , Destoumieux-Garzon Delphine , Mitta Guillaume , Gourbal Benjamin , Montagnani Caroline
Published: March 2020

In the last decade, important discoveries have shown that resistance to reinfection can be achieved without a functional adaptive immune system, introducing the concept of innate immune memory in invertebrates. However, this field has been constrained by the limited number of molecular mechanisms evidenced to support these phenomena. Taking advantage of an invertebrate species, the Pacific oyster (
Crassostrea gigas
), in which we evidenced one of the longest and most effective periods of protection against viral infection observed in an invertebrate, we provide the first comprehensive transcriptomic analysis of antiviral innate immune priming. We show that priming with poly(I·C) induced a massive upregulation of immune-related genes, which control subsequent viral infection, and it was maintained for over 4 months after priming. This acquired resistant mechanism reinforces the molecular foundations of the sustained response model of immune priming. It opens the way to pseudovaccination to prevent the recurrent diseases that currently afflict economically or ecologically important invertebrates.
The Pseudomonas aeruginosa Lectin LecB Causes Integrin Internalization and Inhibits Epithelial Wound Healing
Authors: Thuenauer Roland , Landi Alessia , Trefzer Anne , Altmann Silke , Wehrum Sarah , Eierhoff Thorsten , Diedrich Britta , Dengjel Jörn , Nyström Alexander , Imberty Anne , Römer Winfried
Published: March 2020

Pseudomonas aeruginosa
is a ubiquitous environmental bacterium that is one of the leading causes of nosocomial infections.
P. aeruginosa
is able to switch between planktonic, intracellular, and biofilm-based lifestyles, which allows it to evade the immune system as well as antibiotic treatment. Hence, alternatives to antibiotic treatment are urgently required to combat
P. aeruginosa
infections. Lectins, like the fucose-specific LecB, are promising targets, because removal of LecB resulted in decreased virulence in mouse models. Currently, several research groups are developing LecB inhibitors. However, the role of LecB in host-pathogen interactions is not well understood. The significance of our research is in identifying cellular mechanisms of how LecB facilitates
P. aeruginosa
infection. We introduce LecB as a new member of the list of bacterial molecules that bind integrins and show that
P. aeruginosa
can move forward underneath attached epithelial cells by loosening cell-basement membrane attachment in a LecB-dependent manner.
Corrective steps to enhance ventilation in the delivery room
Authors: Yang Kesi C , te Pas Arjan B , Weinberg Danielle D , Foglia Elizabeth E
Published: March 2020

Objective

The clinical impact of ventilation corrective steps for delivery room positive pressure ventilation (PPV) is not well studied. We aimed to characterise the performance and effect of ventilation corrective steps (MRSOPA (Mask adjustment, Reposition airway, Suction mouth and nose, Open mouth, Pressure increase and Alternative airway)) during delivery room resuscitation of preterm infants.

Design

Prospective observational study of delivery room PPV using video and respiratory function monitor recordings.

Setting

Tertiary academic delivery hospital.

Patients

Preterm infants <32 weeks gestation.

Main outcome measure

Mean exhaled tidal volume (Vte) of PPV inflations before and after MRSOPA interventions, categorised as inadequate (<4 mL/kg); appropriate (4–8 mL/kg), or excessive (>8 mL/kg). Secondary outcomes were leak (>30%) and obstruction (Vte <1 mL/kg), and infant heart rate.

Results

There were 41 corrective interventions in 30 infants, with a median duration of 15 (IQR 7–29) s. The most frequent intervention was a combination of Mask/Reposition and Suction/Open. Mean Vte was inadequate before 16/41 interventions and became adequate following 6/16. Mean Vte became excessive after 6/41 interventions. Mask leak, present before 13/41 interventions, was unchanged after 4 and resolved after 9. Obstruction was present before five interventions and was subsequently resolved only once. MRSOPA interventions introduced leak in two cases and led to obstruction in one case. The heart rate was <100 beats per minute before 31 interventions and rose to >100 beats per minute after 14/31 of these.

Conclusions

Ventilation correction interventions improve tidal volume delivery in some cases, but lead to ineffective or excessive tidal volumes in others. Mask leak and obstruction can be induced by MRSOPA manoeuvres.
Functional abdominal pain: what clinicians need to know
Authors: Andrews Edward Thomas , Beattie R Mark , Tighe Mark P
Published: March 2020

Abdominal pain in childhood is extremely common and presents frequently to both primary and secondary care, with many children having recurrent pain which impacts on daily functioning. Despite this most children have no discernible underlying pathology. We discuss the underlying mechanism for functional abdominal pain (visceral hypersensitivity), the evidence base linking parental anxiety and patient symptoms, and how parents can be supported in managing their children’s symptoms by addressing questions commonly asked by children and families. We look at the evidence for a one-stop rational approach to investigation including a coeliac screen, inflammatory markers and consideration of stool faecal calprotectin, in the absence of red flags. We evaluate commonly used treatments for functional abdominal pain, within a context of managing family expectations. Given the limitations in pharmacological treatment options, trials of probiotics, peppermint oil, mebeverine and (for short-term use only) hyoscine butylbromide may be appropriate. Psychological interventions including cognitive–behavioural therapy, distraction techniques and hypnotherapy have a better evidence base. There is also some evidence for other complementary therapies in children, including yoga and neurostimulation. Outcome is generally good providing there is child and family acceptance of the multiple factors implicated in the aetiology of the pain.
Demyelinating steroid-responsive neurobrucellosis
Authors: Ata Fateen , Yousaf Zohaib , Sharif Mohammad Khalid , Abdallah Ahmed
Published: March 2020

Young man with acute onset nausea, vomiting, joint pain, abdominal pain, fever and weight loss was found to have gait ataxia and positiveBrucellatitres. He deteriorated despite appropriate antibiotics and developed confusion and disorientation. Lumbar puncture revealed lymphocytosis with high protein and low glucose. MRI showed diffuse demyelination. Pulse steroids resulted in rapid clinical, biochemical and radiological recovery.
The global and regional burden of genital ulcer disease due to herpes simplex virus: a natural history modelling study
Authors: Looker Katharine Jane , Johnston Christine , Welton Nicky J , James Charlotte , Vickerman Peter , Turner Katherine M E , Boily Marie-Claude , Gottlieb Sami L
Published: March 2020

Introduction

Herpes simplex virus (HSV) infection can cause painful, recurrent genital ulcer disease (GUD), which can have a substantial impact on sexual and reproductive health. HSV-related GUD is most often due to HSV type 2 (HSV-2), but may also be due to genital HSV type 1 (HSV-1), which has less frequent recurrent episodes than HSV-2. The global burden of GUD has never been quantified. Here we present the first global and regional estimates of GUD due to HSV-1 and HSV-2 among women and men aged 15–49 years old.

Methods

We developed a natural history model reflecting the clinical course of GUD following HSV-2 and genital HSV-1 infection, informed by a literature search for data on model parameters. We considered both diagnosed and undiagnosed symptomatic infection. This model was then applied to existing infection estimates and population sizes for 2016. A sensitivity analysis was carried out varying the assumptions made.

Results

We estimated that 187 million people aged 15–49 years had at least one episode of HSV-related GUD globally in 2016: 5.0% of the world’s population. Of these, 178 million (95% of those with HSV-related GUD) had HSV-2 compared with 9 million (5%) with HSV-1. GUD burden was highest in Africa, and approximately double in women compared with men. Altogether there were an estimated 8 billion person-days spent with HSV-related GUD globally in 2016, with 99% of days due to HSV-2. Taking into account parameter uncertainty, the percentage with at least one episode of HSV-related GUD ranged from 3.2% to 7.9% (120–296 million). However, the estimates were sensitive to the model assumptions.

Conclusion

Our study represents a first attempt to quantify the global burden of HSV-related GUD, which is large. New interventions such as HSV vaccines, antivirals or microbicides have the potential to improve the quality of life of millions of people worldwide.
Returning to daily life: a qualitative interview study on parents of childhood cancer survivors in Germany
Authors: Peikert Mona L , Inhestern Laura , Krauth Konstantin A , Escherich Gabriele , Rutkowski Stefan , Kandels Daniela , Bergelt Corinna
Published: March 2020

Objectives

To investigate experiences of parents of paediatric cancer survivors in cancer-related changes in the parents’ daily life (work life, family life, partner relationship and social life) during and after intensive cancer treatment and to examine the reintegration process with its impeding and facilitating factors.

Design

The design of this cross-sectional study involves a qualitative content analysis of semistructured interviews.

Setting

Participants were consecutively recruited in clinical settings throughout Germany.

Participants

Forty-nine parents (59% female) of 31 cancer survivors (aged 0–17 at diagnosis of leukaemia or central nervous system tumour) were interviewed approximately 16–24 months after the end of intensive cancer treatment (eg, chemotherapy).

Results

During treatment, more than 70% of parents reported difficulties reconciling paid work, household and family responsibilities and caring for the ill child. Couples spent little time with each other and approximately 25% reported dispute and burden. Many parents did not have enough energy for pursuing any hobbies during treatment. However, over the long term, being faced with the child’s disease also led to strengthened relationships, new priorities, improved communication, increased mutual trust and greater appreciation for daily life. Supportive social networks (family/friends/employers), a strong partner relationship prior to the diagnosis and the use of psychosocial services (eg, family-oriented rehabilitation) had a positive impact. At the time of the interview, most families had adapted well. However, reintegration took time and some parents lacked the energy required to continue life as they did before the diagnosis.

Conclusions

Even though most parents successfully readjusted to a new ‘normality’, reintegrating into daily life after paediatric cancer treatment remains difficult. Professional psychosocial support could help families with the reintegration process. Lastly, clinical staff (eg, physicians, psychologists, social workers) should bear in mind that the burden of parents does not automatically end with the end of intensive cancer treatment.
Estimating expected life-years and risk factor associations with mortality in Finland: cohort study
Authors: Härkänen Tommi , Kuulasmaa Kari , Sares-Jäske Laura , Jousilahti Pekka , Peltonen Markku , Borodulin Katja , Knekt Paul , Koskinen Seppo
Published: March 2020

Objective

To develop a tool to inform individuals and general practitioners about benefits of lifestyle changes by providing estimates of the expected age of death (EAD) for different risk factor values, and for those who plan and decide on preventive activities and health services at population level, to calculate potential need for these.

Design

Prospective cohort study to estimate EAD using a model with 27 established risk factors, categorised into four groups: (1) sociodemographic background and medical history, (2) lifestyles, (3) life satisfaction, and (4) biological risk factors. We apply a Poisson regression model on the survival data split into 1-year intervals.

Participants

Total of 38 549 participants aged 25–74 years at baseline of the National FINRISK Study between 1987 and 2007.

Primary outcome measures

Register-based comprehensive mortality data from 1987 to 2014 with an average follow-up time of 16 years and 4310 deaths.

Results

Almost all risk factors included in the model were statistically significantly associated with death. The largest influence on the EAD appeared to be a current heavy smoker versus a never smoker as the EAD for a 30-year-old man decreased from 86.8 years, which corresponds to the reference values of the risk factors, to 80.2 years. Diabetes decreased EAD by >6.6 years. Whole or full milk consumers had 3.4 years lower EAD compared with those consuming skimmed milk. Physically inactive men had 2.4 years lower EAD than those with high activity. Men who found their life almost unbearable due to stress had 2.8 years lower EAD.

Conclusions

The biological risk factors and lifestyles, and the factors connected with life satisfaction were clearly associated with EAD. Our model for estimating a person’s EAD can be used to motivate lifestyle changes.
Cross-sectional study of aggression against Spanish nursing personnel and effects on somatisation of physical symptoms
Authors: Pérez-Fuentes María del Carmen , Molero Jurado María del Mar , Martos Martínez África , Simón Márquez María del Mar , Oropesa Ruiz Nieves Fátima , Gázquez Linares José Jesús
Published: March 2020

Introduction

Violence against nursing personnel in their place of work is a severe problem generating important consequences for these workers. Even though there is a large body of research on the subject, the emotional impact of aggression against healthcare workers continues to be debated.

Objectives

The objective of this quantitative, observational cross-sectional study was to analyse the effects of aggression against nursing personnel and the mediating role of anxiety in somaticising physical symptoms.

Method

The sample was made up of 1357 nursing professionals who answered questionnaires evaluating their sensitivity to anxiety and the presence of somatic symptoms.

Results

Of the professionals who indicated that they had been the victims of aggression by family members or patients in the previous year, 52.8% said it had happened to them on one occasion, 25.2% had experienced two episodes, while 6.9% and 15.1% said they had undergone three or more aggressions, respectively. Although 89.3% of the professionals affected by acts of indicated that they had not undergone physical or psychological consequences, there was a higher prevalence of somatic alteration among workers who had been victims of violence in the workplace. Furthermore, aggression at work had a direct effect on physical somatisation, which in turn acted as a mediator in the level of anxiety of nursing professionals. Thus, aggression increased the level of anxiety of nurses through the appearance of somatic symptoms.

Conclusions

The results are discussed based on some of the consequences that appeared after episodes of aggression in the healthcare sector and their relationship.