bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colonization of Butchers with Livestock‐Associated Methicillin‐Resistant Staphylococcus aureus
Authors: Boost M. , Ho J. , Guardabassi L. , O'Donoghue M. 
Published: December 2012

SummaryReports have documented colonization of swine in Europe, North America and more recently in China with livestock‐associated methicillin‐resistant Staphylococcus aureus (LA‐MRSA). Contamination of pig farmers, veterinarians and abattoir workers with these strains has been observed. However, although contamination levels of 10% of retail pork were reported from the Netherlands and Canada, there are limited data of contamination rates of workers handling raw meat. We investigated the rates of MRSA contamination of local butchers working in wet markets, where recently slaughtered pigs are cut up. Nasal swabs collected from 300 pork butchers at markets throughout Hong Kong were enriched in brain heart infusion broth with 5% salt and cultured on MRSASelect®. Isolates were confirmed as Staphylococcus aureus and susceptibility testing performed. The presence of mecA was confirmed, SCCmec and spa type determined and relatedness investigated by PFGE. Subjects completed a questionnaire on MRSA carriage risk factors. Seventeen samples (5.6%) yielded MRSA, 15 harbouring SCCmec IVb. Ten strains were t899 (CC9), previously reported from local pig carcasses. Five strains were healthcare associated: SCCmec type II, t701(CC6), colonizing two subjects at the same establishment, and single isolates of t008 (CC8), t002 (CC5) and t123 (CC45). The remaining isolates were t359 (CC97), previously reported from buffaloes, and t375 (CC5), reported from bovine milk. None of these butchers reported recent hospitalization or a healthcare worker in the family. Two had recently received antibiotics, one for a skin infection. Four reported wound infections within the last year. All were exposed to meat for >9 h per day. Carriage of MRSA was higher in butchers than in the general community. Although five strains were probably of healthcare origin, the high incidence of t899 (CC9) suggests that cross‐contamination from pork occurs frequently. Washing of hands after touching raw pork is advised.
Serodiagnosis of Human Cutaneous Anthrax in India Using an Indirect Anti-Lethal Factor IgG Enzyme-Linked Immunosorbent Assay
Authors: Ghosh N. , Tomar I. , Lukka H. , Goel A. K. 
Published: December 2012

ABSTRACT

Anthrax, caused by
Bacillus anthracis
, is primarily a zoonotic disease. Being a public health problem also in several developing countries, its early diagnosis is very important in human cases. In this study, we describe the use of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-lethal factor (anti-LF) IgG in human serum samples. A panel of 203 human serum samples consisting of 50 samples from patients with confirmed cutaneous anthrax, 93 samples from healthy controls from areas of India where anthrax is nonendemic, 44 samples from controls from an area of India where anthrax is endemic, and 16 patients with a disease confirmed not to be anthrax were evaluated with an anti-LF ELISA. The combined mean anti-LF ELISA titer for the three control groups was 0.136 ELISA unit (EU), with a 95% confidence interval (CI) of 0.120 to 0.151 EU. The observed sensitivity and specificity of the ELISA were 100% (95% CI, 92.89 to 100%) and 97.39% (95% CI, 93.44 to 99.28%), respectively, at a cutoff value of 0.375 EU, as decided by receiver operating characteristic (ROC) curve analysis. The likelihood ratio was found to be 49.98. The positive predictive value (PPV), negative predictive value (NPV), efficiency, and Youden's index (
J
) for reliability of the assay were 92.5%, 100%, 98.02%, and 0.97, respectively. The false-positive predictive rate and false-negative predictive rate of the assay were 2.61% and 0%. The assay could be a very useful tool for early diagnosis of cutaneous anthrax cases, as antibodies against LF appear much earlier than those against other anthrax toxins in human serum samples.
Serodiagnostic Potential of Mycobacterium avium MAV2054 and MAV5183 Proteins
Authors: Shin A-Rum , Lee Kil-Soo , Lee Kang In , Shim Tae Sun , Koh Won-Jung , Jeon Haet Sal , Son Yeo-Jin , Shin Sung-Jae , Kim Hwa-Jung 
Published: December 2012

ABSTRACT

The
Mycobacterium avium
-
M. intracellulare
complex (MAC) causes a pulmonary disease (PD) similar to tuberculosis (TB). Diagnosis of MAC-PD is complicated and time-consuming. In this study, the serodiagnostic potential of the newly identified MAV2054 and MAV5183 proteins was evaluated in subjects with MAC-PD, pulmonary TB, or latent TB and in noninfected healthy controls (HC), together with HspX and the 38-kDa antigen, well-known serodiagnostic
M. tuberculosis
antigens. All four antigens evoked significantly higher IgG responses in MAC-PD and active TB than in latent TB and HC subjects. Among the antigens, MAV2054 elicited the highest antibody responses in pulmonary TB and MAC-PD patients. IgG titers against MAV2054 and MAV5183 were significantly higher in MAC-PD than in pulmonary TB subjects. In addition, the levels of IgG against all antigens in the
M. intracellulare
and fibrocavitary forms were higher than those in the
M. avium
and nodular bronchiectatic forms, respectively. Based on sensitivity and receiver operator characteristic curve analysis, the best candidates for detection of MAC-PD and pulmonary TB were MAV2054 and the 38-kDa antigen, respectively. In total, 76.0% of MAC-PD and 65.0% of active TB patients were reactive to at least two antigens. In contrast, only 2.8% of HC subjects were reactive with two or more antigens. Our findings suggest that an enzyme-linked immunosorbent assay (ELISA) using the four antigens would be valuable for screening for mycobacterial lung disease, including MAC-PD and pulmonary TB, although it does not provide good discrimination of the disease-causing pathogens.
Mechanisms of Linezolid Resistance among Staphylococci in a Tertiary Hospital
Authors: Quiles-Melero Inmaculada , Gómez-Gil Rosa , Romero-Gómez María Pilar , Sánchez-Díaz Ana María , de Pablos Manuela , García-Rodriguez Julio , Gutiérrez Avelino , Mingorance Jesús 
Published: December 2012

ABSTRACT

The mechanisms of linezolid resistance among 86 staphylococcal isolates from two intensive care units were investigated. The most frequent was the G2576T mutation in the 23S rRNA (82%). The
cfr
gene was found in 17% of the isolates, seven
S. aureus
and eight
S. epidermidis
isolates. Four of the
S. epidermidis
isolates had the G2576T mutation and the
cfr
gene. In four
S. haemolyticus
isolates, the mechanism could not be identified.
Changes in Molecular Epidemiology of Streptococcus pneumoniae Causing Meningitis following Introduction of Pneumococcal Conjugate Vaccination in England and Wales
Authors: Pichon Bruno , Ladhani Shamez N. , Slack Mary P. E. , Segonds-Pichon Anne , Andrews Nick J. , Waight Pauline A. , Miller Elizabeth , George Robert 
Published: December 2012

ABSTRACT
The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in September 2006 has markedly reduced the burden of invasive pneumococcal disease (IPD) including meningitis in England and Wales. This study examined changes in the molecular epidemiology of pneumococcal isolates causing meningitis from July 2004 to June 2009. The Health Protection Agency conducts enhanced pneumococcal surveillance in England and Wales. In addition to serotyping, pneumococcal isolates causing meningitis were genotyped by multilocus sequence typing (MLST). A total of 1,030 isolates were both serotyped and genotyped over the 5-year period. Fifty-two serotypes, 238 sequence types (STs), and 87 clonal complexes were identified, with no significant difference in the yearly Simpson's diversity index values (range, 0.974 to 0.984). STs commonly associated with PCV7 serotypes declined following PCV implementation, with a proportionally greater decline in ST124 (commonly associated with serotype 14). No other ST showed significant changes in distribution, even within individual serotypes. Replacement disease following PCV7 introduction was mainly due to serotypes 1, 3, 7F, 19A, 22F, and 33F through clonal expansion. A single instance of possible capsule switching was identified where one ST4327 clone expressed a serotype 14 capsule in 2005 and a serotype 28A capsule in 2009. In 2008 to 2009, ST191 (7F) became the most prevalent clone causing meningitis (10.3%). Case fatality (145 fatalities/1,030 cases; 14.1%) was high across all age groups and serotype groups. Thus, the introduction of PCV7 resulted in an increase in non-PCV7 serotypes, including some not covered by the 13-valent vaccine, such as serotypes 22F and 33F, emphasizing the importance of long-term epidemiological and molecular surveillance.
Multiplex Real-Time PCR Assay for Detection of Methicillin-Resistant Staphylococcus aureus (MRSA) Strains Suitable in Regions of High MRSA Endemicity
Authors: Kim Jeong-Uk , Cha Choong-Hwan , An Hae-Kyong , Lee Ho-Jun , Kim Mi-Na 
Published: December 2012

ABSTRACT

A multiplex real-time PCR assay that simultaneously detects the
mecA
, staphylococcal cassette chromosome (SCC
mec
)-open reading frame X (
orfX
) junction, and staphylococcal 16S rRNA genes was developed and evaluated using 444 staphylococcal strains. We demonstrated that this assay resulted in fewer false-positive results than a single-locus real-time PCR assay that amplified the SCC
mec-orfX
junction. This assay would be useful in a clinical laboratory in a region of high endemicity for methicillin-resistant
Staphylococcus aureus
(MRSA) infections.
Nationwide Study of Candidemia, Antifungal Use, and Antifungal Drug Resistance in Iceland, 2000 to 2011
Authors: Asmundsdottir Lena Ros , Erlendsdottir Helga , Gottfredsson Magnus 
Published: December 2012

ABSTRACT

Candidemia is often a life-threatening infection, with highly variable incidence among countries. We conducted a nationwide study of candidemia in Iceland from 2000 to 2011, in order to determine recent trends in incidence rates, fungal species distribution, antifungal susceptibility patterns, and concurrent antifungal consumption. A total of 208 infection episodes in 199 patients were identified. The average incidence during the 12 years was 5.7 cases/100,000 population/year, which was significantly higher than that from 1990 to 1999 (4.3/100,000/year;
P
= 0.02). A significant reduction in the use of blood cultures was noted in the last 3 years of the study, coinciding with the economic crisis in the country (
P
< 0.001). Age-specific incidence rates were highest among patients at the extremes of age, 20.7/100,000 for <1 year of age and 18.1/100,000 for >60 years, and varied by gender. Age-specific incidence among males >80 years old was 28.6/100,000/year, and it was 8.3/100,000/year for females in this age group (
P
= 0.028). The 30-day survival rate among adult patients remained unchanged compared to that from 1990 to 1999 (70.4% versus 69.5%,
P
= 0.97).
Candida albicans
was the predominant species (56%), followed by
C. glabrata
(16%) and
C. tropicalis
(13%). The species distribution remained stable compared to that from previous decades. Fluconazole use increased 2.4-fold from 2000 to 2011, with no increase in resistance. In summary, the incidence of candidemia in Iceland has continued to increase but may have reached a steady state, and no increase in antifungal drug resistance has been noted. Decreased use of blood cultures toward the end of the study may have influenced detection rates.
Genetic Analysis of Glycopeptide-Resistant Staphylococcus epidermidis Strains from Bone and Joint Infections
Authors: Cremniter Julie , Sivadon-Tardy Valérie , Caulliez Charlotte , Bauer Thomas , Porcher Raphaël , Lortat-Jacob Alain , Piriou Philippe , Judet Thierry , Aegerter Philippe , Herrmann Jean-Louis , Gaillard Jean-Louis , Rottman Martin 
Published: December 2012

ABSTRACT

Glycopeptide-resistant
Staphylococcus epidermidis
(GRSE) strains are of increasing concern in bone and joint infections (BJIs). Using multilocus sequence typing and multilocus variable-number tandem repeat analysis, we show that BJI-associated GRSE strains are genetically diverse but arise from related, multiresistant hospital sequence types (STs), mostly ST2, ST5, and ST23.
Vascular Endothelial Growth Factor A Promotes Vaccinia Virus Entry into Host Cells via Activation of the Akt Pathway
Authors: Hiley Crispin T. , Chard Louisa S. , Gangeswaran Rathi , Tysome James R. , Briat Arnaud , Lemoine Nicholas R. , Wang Yaohe 
Published: December 2012

ABSTRACT

Vaccinia virus (VV) is an enveloped DNA virus from the poxvirus family and has played a crucial role in the eradication of smallpox. It continues to be used in immunotherapy for the prevention of infectious diseases and treatment of cancer. However, the mechanisms of poxvirus entry, the host factors that affect viral virulence, and the reasons for its natural tropism for tumor cells are incompletely understood. By studying the effect of hypoxia on VV infection, we found that vascular endothelial growth factor A (VEGF-A) augments oncolytic VV cytotoxicity. VEGF derived from tumor cells acts to increase VV internalization, resulting in increased replication and cytotoxicity in an AKT-dependent manner in both tumor cells and normal respiratory epithelial cells. Overexpression of VEGF also enhances VV infection within tumor tissue
in vivo
after systemic delivery. These results highlight the importance of VEGF expression in VV infection and have potential implications for the design of new strategies to prevent poxvirus infection and the development of future generations of oncolytic VV in combination with conventional or biological therapies.
A Vesicular Stomatitis Virus-Based Therapeutic Vaccine Generates a Functional CD8 T Cell Response to Hepatitis B Virus in Transgenic Mice
Authors: Cobleigh Melissa A. , Wei Xin , Robek Michael D. 
Published: December 2012

ABSTRACT
Recombinant vesicular stomatitis virus (VSV) is a promising therapeutic vaccine platform. Using a transgenic mouse model of chronic hepatitis B virus (HBV) infection, we evaluated the therapeutic potential of a VSV vector expressing the HBV middle surface envelope glycoprotein (MS). VSV-MS immunization generated HBV-specific CD8 T cell and antibody responses in transgenic mice that express low HBV antigen levels. These findings support the further development of VSV as a therapeutic vaccine vector for chronic HBV.
Enhancement of Antiviral Activity of Human Alpha-Defensin 5 against Herpes Simplex Virus 2 by Arginine Mutagenesis at Adaptive Evolution Sites
Authors: Wang Aiping , Chen Fang , Wang Yingjie , Shen Mingqiang , Xu Yang , Hu Jian , Wang Song , Geng Fang , Wang Cheng , Ran Xinze , Su Yongping , Cheng Tianmin , Wang Junping 
Published: December 2012

ABSTRACT

Herpes simplex virus 2 (HSV-2) infection is still one of the common causes of sexually transmitted diseases worldwide. The prevalence of HSV strains resistant to traditional nucleoside antiviral agents has led to the development of novel antiviral drugs. Human alpha-defensin 5 (HD5), a kind of endogenous antimicrobial peptide expressed in the epithelia of the small intestine and urogenital tract, displays natural antiviral activity. Based on arginine-rich features and adaptive evolution characteristics of vertebrate defensins, we conducted a screen for HD5 derivatives with enhanced anti-HSV-2 activity by a single arginine substitution at the adaptive evolution sites. Cell protection assay and temporal antiviral studies showed that HD5 and its mutants displayed affirmatory but differential anti-HSV-2 effects
in vitro
by inhibiting viral adhesion and entry. Inspiringly, the E21R-HD5 mutant had significantly higher antiviral activity than natural HD5, which is possibly attributed to the stronger binding affinity of the E21R-HD5 mutant with HSV-2 capsid protein gD, indicating that E21R mutation can increase the anti-HSV-2 potency of HD5. In a mouse model of lethal HSV-2 infection, prophylactic and/or therapeutic treatment with E21R-HD5 via intravaginal instillation remarkably alleviated the symptoms and delayed disease progress and resulted in about a 1.5-fold-higher survival rate than in the HD5 group. Furthermore, the E21R variant exhibited a 2-fold-higher antiviral potency against HIV-1 over parental HD5
in vitro
. This study demonstrates that arginine mutagenesis at appropriate evolution sites may significantly enhance the antiviral activity of HD5, which also paves a facile way to search for potent antiviral drugs based on natural antimicrobial peptides.
Low Oxygen Tension Enhances Hepatitis C Virus Replication
Authors: Vassilaki N. , Kalliampakou K. I. , Kotta-Loizou I. , Befani C. , Liakos P. , Simos G. , Mentis A. F. , Kalliaropoulos A. , Doumba P. P. , Smirlis D. , Foka P. , Bauhofer O. , Poenisch M. , Windisch M. P. , Lee M. E. , Koskinas J. , Bartenschlager R. , Mavromara P. 
Published: December 2012

ABSTRACTLow oxygen tension exerts a significant effect on the replication of several DNA and RNA viruses in cultured cells.In vitropropagation of hepatitis C virus (HCV) has thus far been studied under atmospheric oxygen levels despite the fact that the liver tissue microenvironment is hypoxic. In this study, we investigated the efficiency of HCV production in actively dividing or differentiating human hepatoma cells cultured under low or atmospheric oxygen tensions. By using both HCV replicons and infection-based assays, low oxygen was found to enhance HCV RNA replication whereas virus entry and RNA translation were not affected. Hypoxia signaling pathway-focused DNA microarray and real-time quantitative reverse transcription-PCR (qRT-PCR) analyses revealed an upregulation of genes related to hypoxic stress, glycolytic metabolism, cell growth, and proliferation when cells were kept under low (3% [vol/vol]) oxygen tension, likely reflecting cell adaptation to anaerobic conditions. Interestingly, hypoxia-mediated enhancement of HCV replication correlated directly with the increase in anaerobic glycolysis and creatine kinase B (CKB) activity that leads to elevated ATP production. Surprisingly, activation of hypoxia-inducible factor alpha (HIF-α) was not involved in the elevation of HCV replication. Instead, a number of oncogenes known to be associated with glycolysis were upregulated and evidence that these oncogenes contribute to hypoxia-mediated enhancement of HCV replication was obtained. Finally, in liver biopsy specimens of HCV-infected patients, the levels of hypoxia and anaerobic metabolism markers correlated with HCV RNA levels. These results provide new insights into the impact of oxygen tension on the intricate HCV-host cell interaction.
Analysis of the Costructure of the Simian Virus 40 T-Antigen Origin Binding Domain with Site I Reveals a Correlation between GAGGC Spacing and Spiral Assembly
Authors: Meinke Gretchen , Phelan Paul J. , Harrison Celia J. , Bullock Peter A. 
Published: December 2012

ABSTRACT
Polyomavirus origins of replication contain multiple occurrences of G(A/G)GGC, the high-affinity binding element for the viral initiator T-antigen (T-ag). The site I regulatory region of simian virus 40, involved in the repression of transcription and the enhancement of DNA replication initiation, contains two GAGGC sequences arranged head to tail and separated by a 7-bp AT-rich sequence. We have solved a 3.2-Å costructure of the SV40 origin-binding domain (OBD) bound to site I. We have also established that T-ag assembly on site I is limited to the formation of a single hexamer. These observations have enabled an analysis of the role(s) of the OBDs bound to the site I pentanucleotides in hexamer formation. Of interest, they reveal a correlation between the OBDs bound to site I and a pair of OBD subunits in the previously described hexameric spiral structure. Based on these findings, we propose that spiral assembly is promoted by pentanucleotide pairs arranged in a head-to-tail manner. Finally, the possibility that spiral assembly by OBD subunits accounts for the heterogeneous distribution of pentanucleotides found in the origins of replication of polyomaviruses is discussed.
Differential Replication of Pathogenic and Nonpathogenic Strains of West Nile Virus within Astrocytes
Authors: Hussmann Katherine L. , Samuel Melanie A. , Kim Kwang S. , Diamond Michael S. , Fredericksen Brenda L. 
Published: December 2012

ABSTRACT
The severity of West Nile virus (WNV) infection in immunocompetent animals is highly strain dependent, ranging from avirulent to highly neuropathogenic. Here, we investigate the nature of this strain-specific restriction by analyzing the replication of avirulent (WNV-MAD78) and highly virulent (WNV-NY) strains in neurons, astrocytes, and microvascular endothelial cells, which comprise the neurovascular unit within the central nervous system (CNS). We demonstrate that WNV-MAD78 replicated in and traversed brain microvascular endothelial cells as efficiently as WNV-NY. Likewise, similar levels of replication were detected in neurons. Thus, WNV-MAD78's nonneuropathogenic phenotype is not due to an intrinsic inability to replicate in key target cells within the CNS. In contrast, replication of WNV-MAD78 was delayed and reduced compared to that of WNV-NY in astrocytes. The reduced susceptibility of astrocytes to WNV-MAD78 was due to a delay in viral genome replication and an interferon-independent reduction in cell-to-cell spread. Together, our data suggest that astrocytes regulate WNV spread within the CNS and therefore are an attractive target for ameliorating WNV-induced neuropathology.
Herpesvirus Tegument Protein pUL37 Interacts with Dystonin/BPAG1 To Promote Capsid Transport on Microtubules during Egress
Authors: Pasdeloup David , McElwee Marion , Beilstein Frauke , Labetoulle Marc , Rixon Frazer J. 
Published: December 2012

ABSTRACT

Herpes simplex virus 1 (HSV-1) is a neurotropic virus that travels long distances through cells using the microtubule network. Its 125-nm-diameter capsid is a large cargo which efficiently recruits molecular motors for movement. Upon entry, capsids reach the centrosome by minus-end-directed transport. From there, they are believed to reach the nucleus by plus-end-directed transport. Plus-end-directed transport is also important during egress, when capsids leave the nucleus to reach the site of envelopment in the cytoplasm. Although capsid interactions with dynein and kinesins have been described
in vitro
, the actual composition of the cellular machinery recruited by herpesviruses for capsid transport in infected cells remains unknown. Here, we identify the spectraplakin protein, dystonin/BPAG1, an important cytoskeleton cross-linker involved in microtubule-based transport, as a binding partner of the HSV-1 protein pUL37, which has been implicated in capsid transport. Viral replication is delayed in dystonin-depleted cells, and, using video microscopy of living infected cells, we show that dystonin depletion strongly inhibits capsid movement in the cytoplasm during egress. This study provides new insights into the cellular requirements for HSV-1 capsid transport and identifies dystonin as a nonmotor protein part of the transport machinery.