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Astudy of Pasteurella multocida cells reveals that conditions of iron restriction may lead to a reduction is capsular material thickness. The cells grown in iron-restricted culture media also express iron-regulated proteins. Polymyxin B-gold labelling reveals that cells grown under iron-restricted conditions are heavily labelled unlike cells grown in iron-sufficient conditions.

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Abstract: Motor imagery (MI) refers to the mental simulation of a movement. It is used as a tool to improve motor function in several populations. In young adults, it has been repeatedly shown that MI of upper-limb movements is facilitated when one’s posture is congruent with the movement to simulate. As MI training is notably used for improving locomotor-related activities in older populations, it may be questioned whether subjects’ body configuration could also influence MI of walking movements and whether this influence is preserved with age. In the present study, we examined the impact of one’s body position (congruent with walking: standing/incongruent with walking: sitting) on the duration of walking simulation over two distances (3m/6m), in 26 young (21 females, 5 males; mean: 23.2±2.4years) and 26 elderly (18 females, 8 males; mean: 72.7±5.5years) healthy subjects. It was found that, in both age groups, walking simulation times while standing were shorter than while sitting. Furthermore, walking simulation times in the standing position were closer to actual walking times to cover the same distances. The present findings extend to walking movements the notion that adopting a posture congruent with the movement to imagine facilitates the simulation process. They also suggest that, at least for simple walking tasks, this effect is maintained across the lifespan. The implication of our findings for optimizing MI training of locomotor-related activities is underlined. [Copyright &y& Elsevier]

Rationale: Cerebral palsy (CP) constitutes a substantial portion of paediatric rehabilitation, yet little is known regarding actual occupational therapy (OT) and physical therapy (PT) practices. This study describes OT and PT practices for young children with CP in Quebec, Canada. Methods: This was a cross-sectional survey. All eligible, consenting paediatric occupational therapists (OTs) and physical therapists (PTs) were interviewed using a structured telephone interview based on vignettes of two typical children with CP at two age points - 18 months and 4 years. Reported practices were grouped according to the International Classification of Functioning, Disability and Health (ICF). Results: 91.9% of PTs (n = 62; 83.8% participation rate) and 67.1% of OTs (n = 85; 91.4% participation rate) reported using at least one standardized paediatric assessment. OT and PT interventions focused primarily on impairments and primary function (such as gait function and activities of daily living). Both professions gave little attention to interventions related to play and recreation/leisure. Clinicians reported the need for more training and education specific to CP and to the use of research findings in clinical practice. Conclusion: Wide variations and gaps were identified in clinicians' responses suggesting the need for a basic standard of OT and PT management as well as strategies to encourage knowledge dissemination regarding current best practice. Fundamento: La parálisis cerebral (PC) constituye una parte sustancial de la rehabilitación pediátrica, sin embargo se sabe poco acerca del ejercicio actual de la terapia física (TF) y de la terapia ocupacional (TO). Este estudio describe la aplicación de la TF y de la TO a niños pequeños con PC en Quebec, Canadá. Métodos: Este fue un estudio prospectivo, de corte transversal. Todos los terapistas físicos (TF) y los terapistas ocupacionales (TO) pediátricos elegibles, previo consentimiento, fueron entrevistados utilizando un cuestionario telefónico estructurado basado en viñetas de dos niños típicos con PC a dos edades - 18 meses y 4 años de edad. Las prácticas reportadas fueron agrupadas en base a la Clasificación Internacional de Funcionalidad, discapacidad y salud (CIF). Resultados: 91.9% de los TFs (n = 62; 83.8% rango de participación) y 67.1% de los TOs (n = 85; 91.4% rango de participación) reportaron usar por lo menos una forma de evaluación pediátrica estandarizada. Las intervenciones de TF y TO se enfocaron principalmente en las discapacidades y en las funciones primarias (tales como la marcha y las actividades de la vida diaria). Ambas profesiones prestaron poca atención a las intervenciones relacionadas al juego y a las actividades recreativas y de entretenimiento. Los médicos manifestaron la necesidad de un mayor entrenamiento y educación específicos a la PC y la aplicación de los hallazgos de las investigaciones en la práctica clínica. Conclusión: Se identificaron amplias variaciones y un desconocimiento en las respuestas de los médicos, sugiriendo esto la necesidad de un manejo estándar básico de TF y TO, así como estrategias que impulsen la diseminación del conocimiento en relación a una mejor práctica. Palabras clave: Terapia ocupacional, terapia física, parálisis infantil, Clasificación Internacional de Funcionalidad, tratamiento basado en la evidencia, rehabilitación pediátrica [ABSTRACT FROM AUTHOR]

The aims of this study were to determine if the changes in impairment and disability measures for the upper and lower extremities were equivalent during the post-stroke rehabilitation period and whether the rates of change were maintained 6 months after discharge from rehabilitation. A prospective cohort study design was used. One-hundred-and-thirty-two people who had sustained a stroke and who were enrolled in an intensive functional rehabilitation programme were recruited. Upper and lower extremity impairments and disabilities were evaluated at admission, at discharge from rehabilitation and 6 months later. During active rehabilitation, the changes in both extremities were smaller for the impairment measures (standardized response mean (SRM), 0.37-0.63) than the disability measures (SRM, 0.76-1.05). While the changes in upper and lower extremities were equivalent for impairment measures, they were larger in the lower extremity for disability measures, indicating that the rate of functional improvement was faster in the lower extremity during active rehabilitation. After discharge, however, while the rate of motor recovery in the lower extremity dropped (SRM, 0.54-0.18), it was maintained in the upper extremity (SRM, 0.45 and 0.42). Present findings indicate that functional (disability) measures improve faster than impairment measures in both extremities during the active rehabilitation period and suggest that motor recovery occurs at a different rate in the upper and lower extremities, with that of the upper extremity occurring later and extending into the period after discharge from active rehabilitation. [ABSTRACT FROM AUTHOR]

This study investigated the role of paresis, excessive antagonist coactivation, increased muscle-tendon passive stiffness and spasticity in the reduced stance phase plantarflexor moment (Mmax) and swing phase dorsiflexion during gait (DFmax) in subjects with a recent (<6 months post-stroke) hemiparesis (patients). The gait pattern of the paretic and non-paretic sides was evaluated in 30 patients (aged 57.8±10.8 years), whereas only one side was evaluated in 15 healthy controls (aged 59.1±9.8 years) while walking at natural and very slow speeds. Peak plantarflexor moment (Mmax) and peak medial gastrocnemius (MG) activation during the stance phase, as well as peak dorsiflexion angle (Dfmax) and peak tibialis anterior (TA) activation during the swing phase, were retained for analysis. In addition, a coactivation index and a plantarflexor spasticity index were calculated for both the stance and the swing phase, and plantarflexor passive stiffness was evaluated on an isokinetic dynamometer. The results showed that Mmax on the paretic and non-paretic sides were both reduced compared with control values at natural speed. This reduction was combined to a low MG activation (paresis) on the paretic side. On the non-paretic side, the reduced plantarflexor moment was related to excessive coactivation levels. The swing phase Dfmax tended to be reduced (not significantly) on the paretic side of the patients compared with control values. This reduction was neither associated with excessive antagonist coactivation nor to plantarflexor hyperactive stretch reflexes, but rather to an increased plantarflexor passive stiffness. In some of the patients, however, an increased TA activation that overcame the plantarflexor passive stiffness allowed for normal DFmax values. The functional consequences of the disturbed mechanisms of motor control observed in both the paretic and non-paretic sides are discussed. [Copyright &y& Elsevier]

Objective: To examine 10-m comfortable walking speed and 6-minute distance in healthy individuals and individuals after stroke and to assess the level of disability associated with poor walking endurance after stroke. Design: Descriptive study in which comfortable walking speed over 10 m and distance covered in 6 minutes (6-minute walk test) were compared between healthy subjects and subjects after stroke. Subjects: Twelve healthy subjects and 14 subjects after stroke. Main outcome measures: Walking speed and 6-minute distances were compared between groups. In addition, for each group, actual distance walked in 6 minutes was compared with the distance predicted by the 10-m walking speed test and the distance predicted by normative reference equations. Results: Subjects after stroke had significant reductions in 10-m speed and 6-minute distance compared with healthy subjects (p < 0.05). Subjects after stroke were not able to maintain their comfortable walking speed for 6 minutes, whereas healthy subjects walked in excess of their comfortable speed for 6 minutes. The average distance walked in 6 minutes by individuals after stroke was only 49.8 ± 23.9% of the distance predicted for healthy individuals with similar physical characteristics. Conclusion: In our subjects after stroke, walking speed over a short distance overestimated the distance walked in 6 minutes. Both walking speed and endurance need to be measured and trained during rehabilitation. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE: In this study, we compared the intertrial reliability of resistive torque measurements obtained with hand-held and isokinetic dynamometers and examined the validity of the hand-held dynamometers for the assessment of spastic hypertonia, defined as reflex- and nonreflex-induced resistance to stretch. SUBJECTS: Nine subjects (mean age = 40.6 years) with a chronic (1-5 years) spinal cord injury participated. METHODS: The plantar flexors were stretched at 5 degrees /s (low velocity [LV]) and 180 degrees /s (high velocity [HV]) with an isokinetic dynamometer while the evaluator attempted to match these velocities with a hand-held dynamometer. Electromyographic activity of the soleus and tibialis anterior muscles as well as ankle displacements were recorded. Resistive torque and velocity, measured at -5 degrees of dorsiflexion, were averaged (n = 4). RESULTS: High intraclass correlation coefficients (ICCs) were found at LV and HV for both the hand-held (ICC = .93 and .84) and isokinetic (ICC = .99 and .93) dynamometers. With the hand-held dynamometer, lower resistive torques were found at LV (0.8 N.m) and HV (1.2 N.m), whereas higher velocities were attained at HV. CONCLUSION AND DISCUSSION: The results indicate that the reproducibility of resistive torques obtained with hand-held dynamometry compares with that obtained with isokinetic dynamometry and allows testing of velocities that can be adjusted to the specific level of resistance to stretch. Electromyography confirmed the validity of hand-held dynamometry for assessing reflex and nonreflex components of SH. [ABSTRACT FROM AUTHOR]

Background and Purpose. Studies in subjects with spastic hypertonia indicate that the higher resistance to stretch in the spastic muscles is not only due to hyperactive stretch reflexes but also to changes in the muscle-tendon unit (nonreflex components). The aim of this study was to compare the test-retest reliability of two methods: hand-held dynamometry and isokinetic dynamometry for the evaluation of nonreflex and reflex-mediated resistive force in the plantar flexors of young children with spastic cerebral palsy (CP). Subjects. Ten children 2 to 7 years of age with a diagnosis of spastic CP (either diplegia [n= 7] or hemiplegia [n= 3]) participated in the study. Methods. The resistive force recorded at 0 degrees of dorsiflexion during passive ankle dorsiflexions executed at low and high velocities was evaluated twice at a 1-month interval with a Penny and Giles myometer (a hand-held dynamometer) and a KIN-COM dynamometer. The electromyographic activity of the soleus and tibialis anterior muscles was recorded during KIN-COM testing to detect unwanted activity during low-velocity tests and to identify trials with a reflex response during high-velocity tests. Results. High intraclass correlation coefficients (ICCs) for the resistive force values recorded at the test and retest were computed for both the myometer (ICCs= . 79 and .9O) and the KIN-COM (ICCs= .84 and .84) at low and high velocities, respectively. Coefficients of variation for force values measured at a 1-month interval at low and high velocities were 13.9% and 13.2% with the myometer and 11.8% and 12.8% with the KIN-COM. Conclusion and Discussion. The results suggest that the myometer can provide a measure of spastic hypertonia with a reproducibility and a variation in the measures that compare to those of a computer-controlled dynamometer. From a clinical point of view, the myometer is simpler and cheaper to use given the lower cost and the little time required for testing and data analysis. Care must be taken to select a velocity that is low enough not to evoke a stretch reflex (to isolate nonreflex components) and another that is high enough to elicit a reflex response, so that it becomes possible to differentiate the reflex and nonreflex components involved in spasticity. Such a distinction is important for the choice of treatment procedures. [ABSTRACT FROM AUTHOR]

The mechanism of persistence was characterized in Pseudomonas aeruginosa isolates obtained ten days before (4405), on the tenth day of (4419), and four days after (4478) ciprofloxacin therapy in a cystic fibrosis patient. Isolate 4419 showed a 16-fold increase in resistance to ciprofloxacin, norfloxacin and nalidixic acid. The outer membrane of 4419 had no detectable protein F. A modified lipopolysaccharide profile, a longer lag phase before growth and a slower generation time were also noted for isolate 4419. Cell surface hydrophobicity was increased by 20% in 4419 whereas uptake of [14C]ciprofloxacin was equivalent in all three isolates. Ciprofloxacin doses causing 50% inhibition of DNA synthesis were proportional to MICs for each isolate indicating that the DNA gyrase of 4419 was resistant to quinolones. A quinolone-susceptible revertant of 4419 remained deficient in protein F. Protein F-deficiency was not associated with resistance to quinolones, nor to other antibiotics, supporting the view that it plays little role in outer membrane permeability to antibiotics. [ABSTRACT FROM AUTHOR]

Abstract Background Staphylococcus aureus and Pseudomonas aeruginosa are often found together in the airways of cystic fibrosis (CF) patients. It was previously shown that the P. aeruginosa exoproduct 4-hydroxy-2-heptylquinoline-N-oxide (HQNO) suppresses the growth of S. aureus and provokes the emergence of small-colony variants (SCVs). The presence of S. aureus SCVs as well as biofilms have both been associated with chronic infections in CF. Results We demonstrated that HQNO stimulates S. aureus to form a biofilm in association with the formation of SCVs. The emergence of SCVs and biofilm production under HQNO exposure was shown to be dependent on the activity of the stress- and colonization-related alternative sigma factor B (SigB). Analysis of gene expression revealed that exposure of a prototypical S. aureus strain to HQNO activates SigB, which was leading to an increase in the expression of the fibronectin-binding protein A and the biofilm-associated sarA genes. Conversely, the quorum sensing accessory gene regulator (agr) system and the α-hemolysin gene were repressed by HQNO. Experiments using culture supernatants from P. aeruginosa PAO1 and a double chamber co-culture model confirmed that P. aeruginosa stimulates biofilm formation and activates SigB in a S. aureus strain isolated from a CF patient. Furthermore, the supernatant from P. aeruginosa mutants unable to produce HQNO induced the production of biofilms by S. aureus to a lesser extent than the wild-type strain only in a S. aureus SigB-functional background. Conclusions These results suggest that S. aureus responds to HQNO from P. aeruginosa by forming SCVs and biofilms through SigB activation, a phenomenon that may contribute to the establishment of chronic infections in CF patients.

The use of teat dips is one of the most effective strategies to control mastitis by preventing new intramammary infections. Reducing bacterial load on teat skin helps control the spread of pathogens and spoilage and improves the quality of milk. The objective of this study was to evaluate the reduction of bacterial populations through the application of bacteriocin-based teat formulas. Teats of 12 Holstein cows received 2 different concentrations of bactofencin A, nisin, and reuterin alone or in combination, as well as iodine (positive control) and saline (negative control). Teat swabs were collected before and after application of teat formulas and analyzed for staphylococci, streptococci, and total bacteria counts. There were no differences for staphylococci, streptococci, and total bacterial counts for samples collected before application throughout the entire experiment. Reuterin-low and reuterin-high treatments reduced total bacterial count by 0.47 and 0.36 logs, respectively, whereas bactofencin A had no effect on any tested bacterial groups. Nisin-low treatment reduced staphylococci, streptococci, and total bacterial counts by 0.47, 0.30 and 0.50 logs, respectively. Nisin-high treatment resulted in 0.50, 0.50, and 0.47 log reduction for staphylococci, streptococci, and total bacterial counts. The bacteriocin consortium showed the highest reduction rates with 0.91, 0.54, and 0.90 log reductions obtained for staphylococci, streptococci, and total bacteria counts, respectively, for the low-concentration consortium. Similarly, the high-concentration consortium showed reduction rates with 0.95, 0.60, and 0.82 log reductions obtained for staphylococci, streptococci, and total bacteria counts, respectively. Thus, nisin and the bacteriocin consortium showed the most promise as a teat disinfectant by reducing staphylococci, streptococci, and total bacteria counts. [ABSTRACT FROM AUTHOR]

An Escherichia spp. isolate, ECD-227, was previously identified from the broiler chicken as a phylogenetically divergent and multidrug-resistant Escherichia coli possessing numerous virulence genes. In this study, whole genome sequencing and comparative genome analysis was used to further characterize this isolate. The presence of known and putative antibiotic resistance and virulence open reading frames were determined by comparison to pathogenic (E. coli O157:H7 TW14359, APEC O1:K1:H7, and UPEC UTI89) and nonpathogenic species (E. coli K-12 MG1655 and Escherichia fergusonii ATCC 35469). The assembled genome size of 4.87 Mb was sequenced to 18-fold depth of coverage and predicted to contain 4,376 open reading frames. Phylogenetic analysis of 537 open reading frames present across 110 enteric bacterial species identifies ECD-227 to be E. fergusonii. The genome of ECD-227 contains 5 plasmids showing similarity to known E. coli and Salmonella enterica plasmids. The presence of virulence and antibiotic resistance genes were identified and localized to the chromosome and plasmids. The mutation in gyrA (S83L) involved in fluoroquinolone resistance was identified. The Salmonella-like plasmids harbor antibiotic resistance genes on a class I integron (aadA, qacE?-sul1, aac3-VI, and sulI) as well as numerous virulence genes (iucABCD, sitABCD, cib, traT). In addition to the genome analysis, the virulence of ECD-227 was evaluated in a 1-d-old chick model. In the virulence assay, ECD-227 was found to induce 18 to 30% mortality in 1-d-old chicks after 24 h and 48 h of infection, respectively. This study documents an avian multidrug-resistant and virulent E. fergusonii. The existence of several resistance genes to multiple classes of antibiotics indicates that infection caused by ECD-227 would be difficult to treat using antimicrobials currently available for poultry. [ABSTRACT FROM AUTHOR]