bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidemiology and Risk Factors for Isolation of Escherichia coli Producing CTX-M-Type Extended-Spectrum β-Lactamase in a Large U.S. Medical Center
Authors: Hayakawa Kayoko , Gattu Sureka , Marchaim Dror , Bhargava Ashish , Palla Mohan , Alshabani Khaled , Gudur Uma Mahesh , Pulluru Harish , Bathina Pradeep , Sundaragiri Pranathi Rao , Sarkar Moumita , Kakarlapudi Hari , Ramasamy Balaji , Nanjireddy Priyanka , Mohin Shah , Dasagi Meenakshi , Datla Satya , Kuchipudi Vamsi , Reddy Swetha , Shahani Shobha , Upputuri Vijaya , Marrey Satya , Gannamani Vedavyas , Madhanagopal Nandhini , Annangi Srinadh , Sudha Busani , Muppavarapu Kalyan Srinivas , Moshos Judy A. , Lephart Paul R. , Pogue Jason M. , Bush Karen , Kaye Keith S. 
Published: June 2013

ABSTRACT

A case-case-control study was conducted to identify independent risk factors for recovery of
Escherichia coli
strains producing CTX-M-type extended-spectrum β-lactamases (CTX-M
E. coli
) within a large Southeastern Michigan medical center. Unique cases with isolation of ESBL-producing
E. coli
from February 2010 through July 2011 were analyzed by PCR for
bla
CTX-M
,
bla
TEM
, and
bla
SHV
genes. Patients with CTX-M
E. coli
were compared to patients with
E. coli
strains not producing CTX-M-type ESBLs (non-CTX-M
E. coli
) and uninfected controls. Of 575 patients with ESBL-producing
E. coli
, 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-M
E. coli
(282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-M
E. coli
patients and to uninfected controls. Independent risk factors for CTX-M
E. coli
isolation compared to non-CTX-M
E. coli
included male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillins and/or trimethoprim-sulfamethoxazole. Compared to uninfected controls, independent risk factors for isolation of CTX-M
E. coli
included presence of a urinary catheter, previous urinary tract infection, exposure to oxyimino-cephalosporins, dependent functional status, non-home residence, and multiple comorbid conditions. Within 48 h of admission, community-acquired CTX-M
E. coli
(
n
= 51 [16%]) and non-CTX-M
E coli
(
n
= 11 [19%]) strains were isolated from patients with no recent health care contacts. CTX-M
E. coli
strains were more resistant to multiple antibiotics than non-CTX-M
E. coli
strains. CTX-M-encoding genes, especially
bla
CTX-M-15
type, represented the most common ESBL determinants from ESBL-producing
E. coli
, the majority of which were present upon admission. Septic patients with risk factors for isolation of CTX-M
E. coli
should be empirically treated with appropriate agents. Regional infection control efforts and judicious antibiotic use are needed to control the spread of these organisms.
Borrelia burgdorferi Linear Plasmid 28-3 Confers a Selective Advantage in an Experimental Mouse-Tick Infection Model
Authors: Dulebohn Daniel P. , Bestor Aaron , Rosa Patricia A. 
Published: June 2013

ABSTRACTBorrelia burgdorferi, the bacterium that causes Lyme disease, has a unique segmented genome consisting of numerous linear and circular plasmids and a linear chromosome. Many of these genetic elements have been found to encode factors critical forB. burgdorferito complete the infectious cycle. However, several plasmids remain poorly characterized, and their roles during infection withB. burgdorferihave not been elucidated. To more fully characterize the role of one of the four 28-kb linear plasmids, lp28-3, we generated strains specifically lacking lp28-3 and assayed the contribution of genes carried by lp28-3 toB. burgdorferiinfection. We found that lp28-3 does not carry any genes that are strictly required for infection of a mouse or tick and that lp28-3-deficient spirochetes are competent at causing a disseminated infection. Interestingly, spirochetes containing lp28-3 were at a selective advantage compared to lp28-3-deficient spirochetes when coinjected into a mouse, and this advantage was reflected in the population of spirochetes acquired by feeding ticks. Our data demonstrate that genes carried by lp28-3, although not essential, contribute to the fitness ofB. burgdorferiduring infection.
Induction of Rapid Cell Death by an Environmental Isolate of Legionella pneumophila in Mouse Macrophages
Authors: Tao Lili , Zhu Wenhan , Hu Bi-Jie , Qu Jie-Ming , Luo Zhao-Qing 
Published: June 2013

ABSTRACT

Legionella pneumophila
, the etiological agent for Legionnaires' disease, is ubiquitous in the aqueous environment, where it replicates as an intracellular parasite of free-living protozoa. Our understanding of
L. pneumophila
pathogenicity is obtained mostly from study of derivatives of several clinical isolates, which employ almost identical virulent determinants to exploit host functions. To determine whether environmental
L. pneumophila
isolates interact similarly with the model host systems, we analyzed intracellular replication of several recently isolated such strains and found that these strains cannot productively grow in bone marrow-derived macrophages of A/J mice, which are permissive for all examined laboratory strains. By focusing on one strain called LPE509, we found that its deficiency in intracellular replication in primary A/J macrophages is not caused by the lack of important pathogenic determinants because this strain replicates proficiently in two protozoan hosts and the human macrophage U937 cell. We also found that in the early phase of infection, the trafficking of this strain in A/J macrophages is similar to that of JR32, a derivative of strain Philadelphia 1. Furthermore, infection of these cells by LPE509 caused extensive cell death in a process that requires the Dot/Icm type IV secretion system. Finally, we showed that the cell death is caused neither by the activation of the NAIP5/NLRC4 inflammasome nor by the recently described caspase 11-dependent pathway. Our results revealed that some environmental
L. pneumophila
strains are unable to overcome the defense conferred by primary macrophages from mice known to be permissive for laboratory
L. pneumophila
strains. These results also suggest the existence of a host immune surveillance mechanism differing from those currently known in responding to
L. pneumophila
infection.
Enhanced Susceptibility to Urinary Tract Infection in the Spinal Cord-Injured Host with Neurogenic Bladder
Authors: Balsara Zarine R. , Ross Sherry S. , Dolber Paul C. , Wiener John S. , Tang Yuping , Seed Patrick C. 
Published: June 2013

ABSTRACT

Neurogenic bladder predisposes to recurrent urinary tract infections (UTI) and renal failure, and susceptibility is commonly ascribed to urinary stasis from elevated residual urine volumes.
Escherichia coli
UTI was modeled in the spinal cord-injured (SCI) rat with the hypothesis that SCI animals would require fewer bacteria to establish infection, have an exaggerated inflammatory response, and have delayed clearance of infection compared to normal-voiding controls. T10 SCI rats and controls had median infectious doses (ID
50
) of 10
2
and 10
5
CFU, respectively. Mean residual volumes in the SCI animals did not correlate with susceptibility to initiation of UTI or outcome. In the acute infection, control and SCI rats developed acute cystitis and pyelitis without acute differences in histopathological scores of inflammation. However,
in vivo
imaging of infected animals revealed persistently higher levels of bacteria in the SCI urine and bladders than were seen for controls over 2 weeks. Likewise, at 2 weeks, acute and chronic inflammatory infiltrates persisted in the bladders and kidneys of SCI rats, whereas inflammation largely resolved within the controls. Together these data demonstrate that SCI rats exhibit delayed clearance of infection and exaggerated inflammatory responses in bladders and kidneys; however, the severity of residual volumes does not predict increased susceptibility to UTI. These studies suggest that host-dependent mechanisms that are discrete from alterations in bladder physiology influence UTI susceptibility with the SCI-neurogenic bladder. This model will allow elucidation of SCI-neurogenic bladder-mediated changes in host response that yield UTI susceptibility and may lead to new preventative and therapeutic options.
Contributions of Environmental Signals and Conserved Residues to the Functions of Carbon Storage Regulator A of Borrelia burgdorferi
Authors: Karna S. L. Rajasekhar , Prabhu Rajesh G. , Lin Ying-Han , Miller Christine L. , Seshu J. 
Published: June 2013

ABSTRACT

Carbon storage regulator A of
Borrelia burgdorferi
(CsrA
Bb
) contributes to vertebrate host-specific adaptation by modulating activation of the Rrp2-RpoN-RpoS pathway and is critical for infectivity. We hypothesized that the functions of CsrA
Bb
are dependent on environmental signals and on select residues. We analyzed the phenotype of

csrA
Bb

deletion and site-specific mutants to determine the conserved and pathogen-specific attributes of CsrA
Bb
. Levels of phosphate acetyltransferase (Pta) involved in conversion of acetyl phosphate to acetyl-coenzyme A (acetyl-CoA) and posttranscriptionally regulated by CsrA
Bb
in the

csrA
Bb

mutant were reduced from or similar to those in the control strains under unfed- or fed-tick conditions, respectively. Increased levels of supplemental acetate restored vertebrate host-responsive determinants in the

csrA
Bb

mutant to parental levels, indicating that both the levels of CsrA
Bb
and the acetyl phosphate and acetyl-CoA balance contribute to the activation of the Rrp2-RpoN-RpoS pathway. Site-specific replacement of 8 key residues of CsrA
Bb
(8S) with alanines resulted in increased levels of CsrA
Bb
and reduced levels of Pta and acetyl-CoA, while levels of RpoS, BosR, and other members of
rpoS
regulon were elevated. Truncation of 7 amino acids at the C terminus of CsrA
Bb
(7D) resulted in reduced

csrA
Bb

transcripts and posttranscriptionally reduced levels of FliW located upstream of CsrA
Bb
. Electrophoretic mobility shift assays revealed increased binding of 8S mutant protein to the CsrA binding box upstream of
pta
compared to the parental and 7D truncated protein. Two CsrA
Bb
binding sites were also identified upstream of
fliW
within the
flgK
coding sequence. These observations reveal conserved and unique functions of CsrA
Bb
that regulate adaptive gene expression in
B. burgdorferi
.
Characterization of Intracellular Growth Regulator
icgR
by Utilizing Transcriptomics To Identify Mediators of Pathogenesis in Shigella flexneri
Authors: Morris Carolyn R. , Grassel Christen L. , Redman Julia C. , Sahl Jason W. , Barry Eileen M. , Rasko David A. 
Published: June 2013

ABSTRACT

Shigella
species Gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. With no vaccine available, shigellosis annually kills over 600,000 children in developing countries. This study demonstrates the utility of combining high-throughput bioinformatic methods with
in vitro
and
in vivo
assays to provide new insights into pathogenesis. Comparisons of
in vivo
and
in vitro
gene expression identified genes associated with intracellular growth. Additional bioinformatics analyses identified genes that are present in
S. flexneri
isolates but not in the three other
Shigella
species. Comparison of these two analyses revealed nine genes that are differentially expressed during invasion and that are specific to
S. flexneri
. One gene, a DeoR family transcriptional regulator with decreased expression during invasion, was further characterized and is now designated
icgR
, for
i
ntra
c
ellular
g
rowth
r
egulator. Deletion of
icgR
caused no difference in growth
in vitro
but resulted in increased intracellular replication in HCT-8 cells. Further
in vitro
and
in vivo
studies using high-throughput sequencing of RNA transcripts (RNA-seq) of an isogenic Δ
icgR
mutant identified 34 genes that were upregulated under both growth conditions. This combined informatics and functional approach has allowed the characterization of a gene and pathway previously unknown in
Shigella
pathogenesis and provides a framework for further identification of novel virulence factors and regulatory pathways.
ARTHOSCOPIC REDUCTION AND FIXATION OF FRACTURES OF THE GREATER HUMERAL TUBEROSITY IN ATHLETES: A CASE SERIES
Authors: Tsikouris Georgios , Intzirtis Panagiotis , Zampiakis Emmanouil , Plessas Sotirios , Taprantzis Loukas , Kourougenis Panayiotis , Tsikouris Dimitrios , Tsikouris Lefteris 
Published: June 2013

BackgroundArthroscopy is nowadays a well-establish method to treat a wide range of injuries and overuse syndromes of the shoulder. The role of arthroscopy is extremely important for the treatment of soft-tissue injuries and specific-type fractures of the shoulder.Aimto estimate the applicability of shoulder arthroscopy as an effective method for the treatment of fractures of the greater tuberosity in athletes.Patients–MethodsTwelve athletes (six professional–six recreational, four skiers–two horse riders–two motorcycle racers–one cyclist–one football player–one hardle jumper–one judoka, eight males-four females) with a mean age of 29 (20–45) years, sustaining an avulsion fracture of the greater humeral tuberosity were treated arthroscopically over a 5-year period. Nine were managed acutely and three as malunion and rotator cuff dysfunction cases. For the imaging evaluation, standard plain radiographs (anteroposterior and axillary views), CT scans (with 3D reconstruction) and MRI were performed. In three patients the fragment dislocation was found ≤5 mm, in four was 6–10 mm and in two was more than 10 mm. Anchors were used to fix the avulsed fragment. In nine patients, accompanying soft-tissue lesions (seven rotator cuff tears and two Bankart lesions) were recognized and properly treated. Postoperatively a shoulder abduction brace 30° was applied for six weeks and a careful rehabilitation plan was utilized. Passive external rotation exercises were started immediately.ResultsDuring the follow up period no major complication was observed. Radiographic outcome was assessed on plain X-rays. No patient developed non-union. All patients achieved UCLA scores over 30 at six months. Professionals returned to practicing at 10–12 weeks with customized programs. All athletes returned to their pre-operative activity level with no residual pain.DiscussionThe investigation of indications of shoulder arthroscopy is a continuous process. Surgical familiarity is important to perform advanced techniques in shoulder arthroscopy. Arthroscopic treatment of minimally displaced greater tuberosity fractures should be considered for athletes or people who perform overhead activities.ConclusionsArthroscopic treatment of fractures of the greater humeral tuberosity can offer excellent functional results and permits the treatment of concomitant critical lesions.
RETROSPECTIVE REVIEW OF INJECTION THERAPY IN MORTON'S NEUROMA
Authors: Schiffer G , Chan O , Jalan R , Padhiar N 
Published: June 2013

ObjectiveThe objective is to compare the effectiveness of two different methods of administering injection, ultrasound guided versus palpation guided, for the treatment of Morton's Neuroma.Patients and MethodsThis is a retrospective review of patients who have had corticosteroid-injections as part of their treatment for Morton's Neuroma. A postal-questionnaire using a modified Foot Health Status Questionnaire, reviewing foot-pain, foot function-activity, footwear and general foot health, was utilised and posted to all patients diagnosed with Morton's Neuroma in the Podiatry Clinic between 2001–2006. No inclusion or exclusion criteria were applied.ResultsOf the 104 questionnaires distributed 46 (44.23%) were returned. Subjects who had no corticosteroid injection as treatment for Morton's Neuroma were excluded {14/46 (30.43%)}. Subsequently 32/46 subjects were evaluated. To some extend better results were demonstrated in the palpation guided injection group. There was some evidence of statistical significance (p=0.05) in three questions. Those were concerning the time interval between the last corticosteroid injection and completion of the questionnaire (0.02), work limitation (p=0.048) or walking (0.0482) difficulties secondary to foot problems. No other statistical association was confirmed.ConclusionInjection therapy is often the treatment of choice. No advantage has been demonstrated in this survey of ultrasound guided injection versus palpation guided injection. Further studies are needed to prove the effectiveness of ultrasound guided corticosteroid injection.
THE EPIDEMIOLOGY OF OPEN TIBIAL SHAFT FRACTURES IN SPORTS
Authors: Akhtar Muhammad Adeel , Goudie Stuart , Brown Charles Court 
Published: June 2013

BackgroundTibial shaft fracture is a common sports injury in young athletic population. Open fractures can result in significant morbidity. Our aim was to study the epidemiology, severity and soft tissue coverage of sports related open tibial shaft fractures in the southeast of Scotland over the last 22 years.MethodsWe identified 502 patients from our prospective trauma database between 1988 and 2010 with open tibial shaft fractures and 33 patients (6.5%) had sports related fractures. Demographic details were recorded along with sports played, severity of injuries by using injury severity score, severity of fractures by using Gustillo Anderson classification system and requirement of soft tissue coverage procedures.ResultsThe mean age was 30 years (range- 15–67). 29 (88%) were male and four female (12%). The most common sport played was football in 20 patients (61%) followed by rugby in three patients (9%) skiing, quad bike and horse riding in two patients each (6%) and golf, squash, cycling and sledging in one patient (3%) each.The mean injury severity score was 10.8 (range 10–16). Eleven patients (33%) had grade 1, fifteen patients (46%) had grade 2, five patients (15%) had grade 3a and two patients (6%) had grade 3b injuries according to Gustillo Anderson classification system of open fractures.Eight patients (24%) required soft tissue coverage for the treatment of these fractures. The types of flaps used were fasciocutaneous flap in four patients, split skin graft in three patients and adipofascial flap in four patients.DiscussionWe looked at the epidemiology of open tibia shaft fractures in the southeast of Scotland in last 22 years and found that football was the most common sport (61%) associated with these fractures. 88% patients were male. 21% patients had severe (grade 3) injuries and 24% patients required soft tissue coverage for the treatment of these fractures. This information can help sports physicians in planning orthopaedic and plastic services for the treatment of sports related open tibial shaft fractures.
EFFECT OF UNILATERAL AND BILATERAL USE OF LATERALLY WEDGED INSOLES WITH ARCH SUPPORTS ON IMPACT LOADING IN MEDIAL KNEE OSTEOARTHRITIS
Authors: Abdallah Amira 
Published: June 2013

BackgroundIncreased impact loading is implicated in knee osteoarthritis development and progression. This study examined the initial impact force and first ground reaction force (GRF) peaks, their loading rates, their relative timing to the stance phase timing and the walking speed during unilateral and bilateral use of different inclinations of laterally wedged insoles (LWI) with arch supports.MethodsData were collected from 33 female patients with medial knee osteoarthritis, using an AMPTI forceplate, under five insole conditions (unilateral 6° & 11° and bilateral 0°, 6° & 11°) and a without-insole one.ResultsRepeated measures MANOVA revealed significant (p<0.05) increase in the impact force in the bilateral 11° vs each of the unilateral 6° and without-insole conditions. The impact loading rate decreased significantly in the unilateral 11° vs the bilateral 6° insole condition. The relative timing of the impact force increased significantly in each of the bilateral 6°, bilateral 11° and unilateral 11° vs the bilateral 0° insole condition and in each of the bilateral 11° and unilateral 11° vs the without-insole condition. Moreover, there were significant (p=0.000) positive correlations between the impact and GRF loading rates and the walking speed and each of the impact force, impact loading rate and GRF loading rate. Finally, the Chi-square test revealed insignificant (p>0.05) association between the insole conditions and the presence of impact forces.Discussion/ConclusionPatients with medial knee osteoarthritis are advised to use unilateral 11° LWI and walk slowly to decrease impact loading. Unilateral use of 11° LWI decreases impact loading possibly through increasing foot pronation (Abdallah A.A. & Radwan A.Y., 2011)*.
RECOVERY OF TRANSVERSE STRAIN IN HIGH–STRESS TENDONS FOLLOWING EXERCISE
Authors: Wearing Scott , Locke Simon , Cook Jill , Purdam Craig , Smeathers James , Hooper Sue 
Published: June 2013

BackgroundThis study evaluated the time course of recovery of transverse strain in the Achilles and patellar tendons following a bout of resistance exercise.MethodsSeventeen healthy adults underwent sonographic examination of the right patellar (n=9) or Achilles (n=8) tendons immediately prior to and following 90 repetitions of weight–bearing exercise. Quadriceps and gastrocnemius exercise were performed against an effective resistance of 175% and 250% body weight, respectively. Sagittal tendon thickness was determined 20 mm from the tendon enthesis and transverse strain was repeatedly monitored over a 24 hour recovery period.ResultsResistance exercise resulted in an immediate decrease in Achilles (t7=10.6, P<.01) and patellar (t8=8.9, P<.01) tendon thickness, resulting in an average transverse strain of 0.14±0.04 and 0.18±0.05. While the average strain was not significantly different between tendons, older age was associated with a reduced transverse strain response (r=0.63, P<.01). Recovery of transverse strain, in contrast, was prolonged compared with the duration of loading and exponential in nature. The mean primary recovery time was not significantly different between Achilles (6.5±3.2 hours) and patellar (7.1±3.2 hours) tendons and body weight accounted for 62% and 64% of the variation in recovery time, respectively.DiscussionDespite structural and biochemical differences between the Achilles and patellar tendons,1the mechanisms underlying transverse creep–recovery in vivo appear similar and are highly time dependent. Primary recovery required about 7 hours in healthy tendons, with full recovery requiring up to 24 hours. These in vivo recovery times are similar to those reported for axial creep recovery of the vertebral disc in vitro,2and may be used clinically to guide physical activity to rest ratios in healthy adults. Optimal ratios for high–stress tendons in clinical populations, however, remain unknown and require further attention in light of the knowledge gained in this study.