bluuebunny/crossref_metadata_2025_split huggingface dataset:
Panton-Valentine Leukocidin (PVL)-Positive Health Care-Associated Methicillin-Resistant Staphylococcus aureus Isolates Are Associated with Skin and Soft Tissue Infections and Colonized Mainly by Infective PVL-Encoding Bacteriophages
Authors: Hu Qiwen , Cheng Hang , Yuan Wenchang , Zeng Fangyin , Shang Weilong , Tang Dahai , Xue Wencheng , Fu Jianfeng , Zhou Renjie , Zhu Junmin , Yang Jie , Hu Zhen , Yuan Jizhen , Zhang Xia , Rao Qing , Li Shu , Chen Zhijin , Hu Xiaomei , Wu Xingan , Rao Xiancai 
Published: October 2014

ABSTRACT

The emergence of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant
Staphylococcus aureus
(MRSA) is a public health concern worldwide. PVL is associated with community-associated MRSA and is linked to skin and soft tissue infections (SSTIs). However, PVL genes have also been detected in health care-associated (HA) MRSA isolates. The diseases associated with PVL-positive HA-MRSA isolates and the distributions of PVL-encoding bacteriophages in HA-MRSA have not been determined. In this study, a total of 259 HA-MRSA strains isolated between 2009 and 2012 in China from inpatients with SSTIs, pneumonia, and bacteremia were selected for molecular typing, including staphylococcal cassette chromosome
mec
typing, multilocus sequence typing, and staphylococcal protein A gene typing. The PVL genes and PVL bacteriophages in the MRSA isolates were characterized by PCR. Among the tested MRSA isolates, 28.6% (74/259) were PVL positive. The high prevalence of PVL-carrying HA-MRSA was observed to be associated with SSTIs but not with pneumonia or bacteremia. The PVL-positive HA-MRSA isolates were colonized mainly by infective PVL phages, namely, Φ7247PVL, ΦSLT, and ΦSa2958. The distribution of PVL-carrying bacteriophages differed geographically. Our study highlights the potential risk of the emergence of multidrug-resistant HA-MRSA strains with increased virulence.
Fatal Outcome of Autochthonous Hepatitis E in a Patient with B Cell Lymphoma in Southeastern France
Authors: Doudier Barbara , Verrot Denis , Serratrice Christine , Poucel Christian , Auguste Regine , Colson Philippe 
Published: October 2014

ABSTRACT
We describe a case of fatal fulminant hepatitis E concomitant to malignant B cell lymphoma in a 73-year-old French woman. Infection was with an autochthonous hepatitis E virus of genotype 3f. Frequent consumption of uncooked pig liver sausage (figatellu) was the only risk factor found.
Human Cytomegalovirus UL97 Phosphorylates the Viral Nuclear Egress Complex
Authors: Sharma Mayuri , Bender Brian J. , Kamil Jeremy P. , Lye Ming F. , Pesola Jean M. , Reim Natalia I. , Hogle James M. , Coen Donald M. 
Published: October 2014

ABSTRACT

Herpesvirus nucleocapsids exit the host cell nucleus in an unusual process known as nuclear egress. The human cytomegalovirus (HCMV) UL97 protein kinase is required for efficient nuclear egress, which can be explained by its phosphorylation of the nuclear lamina component lamin A/C, which disrupts the nuclear lamina. We found that a dominant negative lamin A/C mutant complemented the replication defect of a virus lacking UL97 in dividing cells, validating this explanation. However, as complementation was incomplete, we investigated whether the HCMV nuclear egress complex (NEC) subunits UL50 and UL53, which are required for nuclear egress and recruit UL97 to the nuclear rim, are UL97 substrates. Using mass spectrometry, we detected UL97-dependent phosphorylation of UL50 residue S216 (UL50-S216) and UL53-S19 in infected cells. Moreover, UL53-S19 was specifically phosphorylated by UL97
in vitro
. Notably, treatment of infected cells with the UL97 inhibitor maribavir or infection with a
UL97
mutant led to a punctate rather than a continuous distribution of the NEC at the nuclear rim. Alanine substitutions in both UL50-S216 and UL53-S19 resulted in a punctate distribution of the NEC in infected cells and also decreased virus production and nuclear egress in the absence of maribavir. These results indicate that UL97 phosphorylates the NEC and suggest that this phosphorylation modulates nuclear egress. Thus, the UL97-NEC interaction appears to recruit UL97 to the nuclear rim both for disruption of the nuclear lamina and phosphorylation of the NEC.

IMPORTANCE
Human cytomegalovirus (HCMV) causes birth defects and it can cause life-threatening diseases in immunocompromised patients. HCMV assembles in the nucleus and then translocates to the cytoplasm in an unusual process termed nuclear egress, an attractive target for antiviral therapy. A viral enzyme, UL97, is important for nuclear egress. It has been proposed that this is due to its role in disruption of the nuclear lamina, which would otherwise impede nuclear egress. In validating this proposal, we showed that independent disruption of the lamina can overcome a loss of UL97, but only partly, suggesting additional roles for UL97 during nuclear egress. We then found that UL97 phosphorylates the viral nuclear egress complex (NEC), which is essential for nuclear egress, and we obtained evidence that this phosphorylation modulates this process. Our results highlight a new role for UL97, the mutual dependence of the viral NEC and UL97 during nuclear egress, and differences among herpesviruses.
Converting Carbon Dioxide to Butyrate with an Engineered Strain of Clostridium ljungdahlii
Authors: Ueki Toshiyuki , Nevin Kelly P. , Woodard Trevor L. , Lovley Derek R. 
Published: October 2014

ABSTRACT

Microbial conversion of carbon dioxide to organic commodities via syngas metabolism or microbial electrosynthesis is an attractive option for production of renewable biocommodities. The recent development of an initial genetic toolbox for the acetogen
Clostridium ljungdahlii
has suggested that
C. ljungdahlii
may be an effective chassis for such conversions. This possibility was evaluated by engineering a strain to produce butyrate, a valuable commodity that is not a natural product of
C. ljungdahlii
metabolism. Heterologous genes required for butyrate production from acetyl-coenzyme A (CoA) were identified and introduced initially on plasmids and in subsequent strain designs integrated into the
C. ljungdahlii
chromosome. Iterative strain designs involved increasing translation of a key enzyme by modifying a ribosome binding site, inactivating the gene encoding the first step in the conversion of acetyl-CoA to acetate, disrupting the gene which encodes the primary bifunctional aldehyde/alcohol dehydrogenase for ethanol production, and interrupting the gene for a CoA transferase that potentially represented an alternative route for the production of acetate. These modifications yielded a strain in which ca. 50 or 70% of the carbon and electron flow was diverted to the production of butyrate with H
2
or CO as the electron donor, respectively. These results demonstrate the possibility of producing high-value commodities from carbon dioxide with
C. ljungdahlii
as the catalyst.

IMPORTANCE
The development of a microbial chassis for efficient conversion of carbon dioxide directly to desired organic products would greatly advance the environmentally sustainable production of biofuels and other commodities.
Clostridium ljungdahlii
is an effective catalyst for microbial electrosynthesis, a technology in which electricity generated with renewable technologies, such as solar or wind, powers the conversion of carbon dioxide and water to organic products. Other electron donors for
C. ljungdahlii
include carbon monoxide, which can be derived from industrial waste gases or the conversion of recalcitrant biomass to syngas, as well as hydrogen, another syngas component. The finding that carbon and electron flow in
C. ljungdahlii
can be diverted from the production of acetate to butyrate synthesis is an important step toward the goal of renewable commodity production from carbon dioxide with this organism.
Prevention of Respiratory Syncytial Virus Infection: From Vaccine to Antibody
Authors: Huang Kelly , Wu Herren 
Published: October 2014

ABSTRACTRespiratory syncytial virus (RSV) is the leading cause of lower respiratory tract disease in infants and young children. Initial efforts to develop a vaccine to prevent RSV lower respiratory tract disease in children were halted because of serious adverse events that occurred when children were infected with RSV following vaccination, including vaccine-related deaths. Subsequently, a major focus for researchers was to understand what led to these adverse events. Investment in a vaccine for RSV continues, and new strategies are under development. Success to prevent RSV disease was met by the development of immunoprophylaxis, first with intravenous immunoglobulin and then with recombinant monoclonal antibody. The story of immunoprophylaxis for RSV includes the first-in-class use of antibody technology for infectious disease, and palivizumab currently remains the only way to prevent serious lower respiratory tract disease due to RSV infection.
Detection of Shiga Toxin-Producing
Escherichia coli
from Nonhuman Sources and Strain Typing
Authors: Beutin Lothar , Fach Patrick 
Published: October 2014

ABSTRACT

Shiga toxin-producing
Escherichia coli
(STEC) strains are commonly found in the intestine of ruminant species of wild and domestic animals. Excretion of STEC with animal feces results in a broad contamination of food and the environment. Humans get infected with STEC through ingestion of contaminated food, by contact with the environment, and from STEC-excreting animals and humans. STEC strains can behave as human pathogens, and some of them, called enterohemorrhagic
E. coli
(EHEC), may cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS). Because of the diversity of STEC types, detection strategies for STEC and EHEC are based on the identification of Shiga toxins or the underlying genes. Cultural enrichment of STEC from test samples is needed for identification, and different protocols were developed for this purpose. Multiplex real-time PCR protocols (ISO/CEN TS13136 and USDA/FSIS MLG5B.01) have been developed to specifically identify EHEC by targeting the LEE (locus of enterocyte effacement)-encoded
eae
gene and genes for EHEC-associated O groups. The employment of more genetic markers (
nle
and CRISPR) is a future challenge for better identification of EHEC from any kinds of samples. The isolation of STEC or EHEC from a sample is required for confirmation, and different cultivation protocols and media for this purpose have been developed. Most STEC strains present in food, animals, and the environment are
eae
negative, but some of these strains can cause HC and HUS in humans as well. Phenotypic assays and molecular tools for typing EHEC and STEC strains are used to detect and characterize human pathogenic strains among members of the STEC group.
The Inflammatory Response during Enterohemorrhagic
Escherichia coli
Infection
Authors: Pearson Jaclyn S. , Hartland Elizabeth L. 
Published: October 2014

ABSTRACT

The inflammatory response is an integral part of host defense against enterohemorrhagic
Escherichia coli
(EHEC) infection and also contributes to disease pathology. In this article we explore the factors leading to inflammation during EHEC infection and the mechanisms EHEC and other attaching and effacing (A/E) pathogens have evolved to suppress inflammatory signaling. EHEC stimulates an inflammatory response in the intestine through host recognition of bacterial components such as flagellin and lipopolysaccharide. In addition, the activity of Shiga toxin and some type III secretion system effectors leads to increased tissue inflammation. Various infection models of EHEC and other A/E pathogens have revealed many of the immune factors that mediate this response. In particular, the outcome of infection is greatly influenced by the ability of an infected epithelial cell to mount an effective host inflammatory response. The inflammatory response of infected enterocytes is counterbalanced by the activity of type III secretion system effectors such as NleE and NleC that modify and inhibit components of the signaling pathways that lead to proinflammatory cytokine production. Overall, A/E pathogens have taught us that innate mucosal immune responses in the gastrointestinal tract during infection with A/E pathogens are highly complex and ultimate clearance of the pathogen depends on multiple factors, including inflammatory mediators, bacterial burden, and the function and integrity of resident intestinal epithelial cells.
Animal Models of EnterohemorrhagicEscherichia coliInfection
Authors: Ritchie Jennifer M. 
Published: October 2014

ABSTRACTThe first major outbreaks caused by enterohemorrhagicEscherichia coli(EHEC) raised public and medical awareness of the risks associated with acquiring this potentially deadly infection. The widespread presence of these organisms in the environment, the severity of the clinical sequelae, and the lack of treatment options and effective preventive measures demand that we obtain a better understanding of how this group of organisms cause disease. Animal models allow study of the processes and factors that contribute to disease and, as such, form a valuable tool in the repertoire of infectious disease researchers. Yet despite more than 30 years of research, it seems that no single model host reproduces the full spectrum of clinical disease induced by EHEC in humans. In the first part of this review, a synopsis of what is known about EHEC infections is garnered from human outbreaks and biopsy specimens. The main features and limitations of EHEC infection models that are based on the three most commonly used species (pigs, rabbits, and mice) are described within a historical context. Recent advances are highlighted, and a brief overview of models based on other species is given. Finally, the impact of the host on moderating EHEC infection is considered in light of growing evidence for the need to consider the biology and virulence strategies of EHEC in the context of its niche within the intestine.
Nucleotide Metabolism and DNA Replication
Authors: Warner Digby F. , Evans Joanna C. , Mizrahi Valerie 
Published: October 2014

ABSTRACT

The development and application of a highly versatile suite of tools for mycobacterial genetics, coupled with widespread use of “omics” approaches to elucidate the structure, function, and regulation of mycobacterial proteins, has led to spectacular advances in our understanding of the metabolism and physiology of mycobacteria. In this article, we provide an update on nucleotide metabolism and DNA replication in mycobacteria, highlighting key findings from the past 10 to 15 years. In the first section, we focus on nucleotide metabolism, ranging from the biosynthesis, salvage, and interconversion of purine and pyrimidine ribonucleotides to the formation of deoxyribonucleotides. The second part of the article is devoted to DNA replication, with a focus on replication initiation and elongation, as well as DNA unwinding. We provide an overview of replication fidelity and mutation rates in mycobacteria and summarize evidence suggesting that DNA replication occurs during states of low metabolic activity, and conclude by suggesting directions for future research to address key outstanding questions. Although this article focuses primarily on observations from
Mycobacterium tuberculosis
, it is interspersed, where appropriate, with insights from, and comparisons with, other mycobacterial species as well as better characterized bacterial models such as
Escherichia coli
. Finally, a common theme underlying almost all studies of mycobacterial metabolism is the potential to identify and validate functions or pathways that can be exploited for tuberculosis drug discovery. In this context, we have specifically highlighted those processes in mycobacterial DNA replication that might satisfy this critical requirement.
Mycobacterial Biofilms
Authors: Richards Jacobs P. , Ojha Anil K. 
Published: October 2014

ABSTRACT

Bacteria have a natural propensity to grow as sessile, matrix-encapsulated, multicellular communities called biofilms. Formation of biofilms proceeds through genetically programmed, distinct developmental stages signaled by intricate networks of communication among the constituent population and their environment. Growing in the complex and heterogeneous microenvironments of biofilms, the resident bacteria acquire unique phenotypes that are generally not associated with their planktonic counterparts. Most notable among these is an extraordinary level of tolerance to a variety of environmental stresses, including antibiotics. Although mycobacteria have long been observed to spontaneously form complex multicellular structures
in vitro
, it has only recently become apparent that these structures are not only formed through dedicated genetic pathways but are also tolerant to antibiotics. In this article, we review the recent advances in the understanding of mycobacterial biofilms
in vitro
. We further consider the possible linkage between biofilm-like lifestyles and characteristic persistence of mycobacterial infections against host-defense mechanisms as well as antibiotics.
Effects of breed and feed supplementation on the fertility of cows developed for milk production in Zimbabwe
Authors: Garwe E. C. , Hamudikuwanda H. H. , Mutisi C. , Ball P. J. H. 
Published: October 2014

Forty‐six indigenous Sanga‐type (Nkone and Tuli breeds) cows and 46 crossbred (Nkone x Jersey and Tuli x Jersey) cows were randomly allocated to four treatment combinations in a 2 x 2 factorial arrangement with two breeds and two dietary levels, a control diet and a diet supplemented with dairy meal containing 14 per cent crude protein at the rate of 2 kg per cow per day. The progesterone concentration was measured in milk samples taken three times a week from 10 days postpartum for up to 200 days, and the cows' bodyweights and body condition scores were recorded fortnightly. The pregnancy rate in the crossbred cows was significantly higher (P<0·05) than in the indigenous cows, and the assumed pregnancy loss rate 30 days after conception was significantly higher (P<0·05) in the indigenous cows than in the crossbred cows. The supplemented crossbred cows had a lower pregnancy loss rate than the supplemented indigenous cows (P<0·05). All the supplemented indigenous cows that lost pregnancies were in their first parity, whereas all the crossbred cows that lost pregnancies were multiparous and were not supplemented. The indigenous cows weighed significantly more (P<0·05) than the crossbred cows irrespective of diet, and the supplemented cows of both breeds weighed more (P<0·05) than the control cows. The supplemented indigenous cows had significantly higher (P<0·05) body condition scores than the control cows. The mean dairy milk yield of all the breeds was generally low but significantly higher (P<0·05) in the crossbred than in the indigenous cows.
Relationships between physiological variables and race performance in French standardbred trotters
Authors: Leleu C. , Cotrel C. , Courouce‐Malblanc A. 
Published: October 2014

The relationships between V4 (the velocity for a blood lactate concentration of 4 mmol/litre) and V200 (the velocity for a heart rate of 200 bpm) and the performance indices of 223 healthy French trotters were analysed. They were divided into four age groups of three, four, five and six years and over, and into three performance groups (good, intermediate and poor performers) defined by the index of trot (ITR), an annual index of performance calculated by the national stud. V4 and V200 were assessed during the performance of a three‐step standardised field exercise test, and four performance indexes (ITR, earnings, best time and the number of starts) were calculated for each group. An analysis of variance showed that V4 and V200 were highly correlated with the horses’ age and level of performance (P<0·05). The correlation between the physiological variables and ITR was better for the three‐ and four‐year‐old horses than for the older horses.
Evaluation of the analgesic effect of lidocaine and bupivacaine used to provide a brachial plexus block for forelimb surgery in 10 dogs
Authors: Wenger S. , Moens Y. , Jäggin N. , Schatzmann U. 
Published: October 2014

Twenty adult dogs weighing between 1·4 and 53·5 kg and aged between six months and nine years were anaesthetised and the brachial plexus was localised with the aid of a nerve stimulator. In 10 of the dogs a brachial plexus block was induced with a mixture of lidocaine and bupivacaine and the other 10 each received 0·25 ml/kg saline as a control. The end‐tidal isoflurane concentration was maintained between 1·3 and 1·4 per cent during surgery for carpal arthrodesis or a fracture of the radius or ulna. Acute heart rate or blood pressure increases of 20 per cent or more were treated with 1 µg/kg fentanyl intravenously. Postoperatively, signs of pain were scored by a single blinded observer at hourly intervals until eight hours after the block had been induced, on a scale from 0 to 18. Dogs with pain scores above 5 received 0·1 to 0·2 mg/kg methadone intravenously, repeated as necessary. During surgery the control dogs received significantly more fentanyl (median 0·05 µg/kg/minute, range 0·02 to 0·20 µg/kg/minute) than the group given local anaesthetic (median 0 µg/kg/minute, range 0 to 0·02 µg/kg/minute). Postoperatively, the control group required significantly more methadone (median 0·2 mg/kg, range 0·1 to 1 mg/kg) than the treated group (median 0 mg/kg, range 0 to 0·13 mg/kg).
The foot‐and‐mouth disease epidemic in Dumfries and Galloway, 2001. 1: Characteristics and control
Authors: Thrusfield M. , Mansley L. , Dunlop P. , Taylor J. , Pawson A. , Stringer L. 
Published: October 2014

The foot‐and‐mouth disease epidemic in Dumfries and Galloway in south‐west Scotland comprised 177 infected premises (IPs) in 24 geographical clusters, and ran from March 1 until May 23, 2001. Initial seeding of infection was by livestock (predominantly sheep) that had passed through Longtown Market in adjacent Cumbria. Thereafter, spread within existing, and to new, clusters was associated with the movement of personnel and vehicles, with further transmission by Longtown Market contacts and across common boundaries. Sheep and cattle premises were equally affected. After the peak of the epidemic at the beginning of the third week of March, the upper possible limit of attack rates for premises contiguous to IPs, and premises within 3 km, remained around 10 per cent, with new clusters emerging more distantly. Control procedures included traditional methods of slaughter of all animals on IPs and, elsewhere, of animals considered by veterinary assessment to be Dangerous Contacts; movement restrictions; enhanced biosecurity; tracing of potential sources and spread of virus; and surveillance of premises subsequently considered at risk. These methods were supplemented by the novel pre‐emptive slaughter, without veterinary assessment, of all susceptible livestock on all premises contiguous to IPs, and of small ruminants and pigs within a 3 km radius (known as the Protection Zone) around IPs. In total, approximately 80,000 cattle, 564,000 sheep, 2600 pigs and 500 goats were slaughtered, the novel methods accounting for 29 per cent of all cattle and 75 per cent of all sheep killed. Limitations of existing national databases necessitated the development of local databases to administer control procedures.