Comparison of the genome sequence of the poultry pathogen Bordetella avium with those of B. bronchiseptica, B. pertussis, and B. parapertussis reveals extensive diversity in surface structures associated with host interaction

Bordetella avium is a pathogen of poultry and is phylogenetically distinct from Bordetella bronchiseptica, Bordetella pertussis, and Bordetella parapertussis, which are other species in the Bordetella genus that infect mammals. In order to understand the evolutionary relatedness of Bordetella species and further the understanding of pathogenesis, we obtained the complete genome sequence of B. avium strain 197N, a pathogenic strain that has been extensively studied. With 3,732,255 base pairs of DNA and 3,417 predicted coding sequences, it has the smallest genome and gene complement of the sequenced bordetellae. In this study, the presence or absence of previously reported virulence factors from B. avium was confirmed, and the genetic bases for growth characteristics were elucidated. Over 1,100 genes present in B. avium but not in B. bronchiseptica were identified, and most were predicted to encode surface or secreted proteins that are likely to define an organism adapted to the avian rather than the mammalian respiratory tracts. These include genes coding for the synthesis of a polysaccharide capsule, hemagglutinins, a type I secretion system adjacent to two very large genes for secreted proteins, and unique genes for both lipopolysaccharide and fimbrial biogenesis. Three apparently complete prophages are also present. The BvgAS virulence regulatory system appears to have polymorphisms at a poly(C) tract that is involved in phase variation in other bordetellae. A number of putative iron-regulated outer membrane proteins were predicted from the sequence, and this regulation was confirmed experimentally for five of these.     

Understanding How Noncatalytic Carbohydrate Binding Modules Can Display Specificity for Xyloglucan

Plant biomass is central to the carbon cycle and to environmentally sustainable industries exemplified by the biofuel sector. Plant cell wall degrading enzymes generally contain noncatalytic carbohydrate binding modules (CBMs) that fulfil a targeting function, which enhances catalysis. CBMs that bind β-glucan chains often display broad specificity recognizing β1,4-glucans (cellulose), β1,3-β1,4-mixed linked glucans and xyloglucan, a β1,4-glucan decorated with α1,6-xylose residues, by targeting structures common to the three polysaccharides. Thus, CBMs that recognize xyloglucan target the β1,4-glucan backbone and only accommodate the xylose decorations. Here we show that two closely related CBMs, CBM65A and CBM65B, derived from EcCel5A, a Eubacterium cellulosolvens endoglucanase, bind to a range of β-glucans but, uniquely, display significant preference for xyloglucan. The structures of the two CBMs reveal a β-sandwich fold. The ligand binding site comprises the β-sheet that forms the concave surface of the proteins. Binding to the backbone chains of β-glucans is mediated primarily by five aromatic residues that also make hydrophobic interactions with the xylose side chains of xyloglucan, conferring the distinctive specificity of the CBMs for the decorated polysaccharide. Significantly, and in contrast to other CBMs that recognize β-glucans, CBM65A utilizes different polar residues to bind cellulose and mixed linked glucans. Thus, Gln¹⁰⁶ is central to cellulose recognition, but is not required for binding to mixed linked glucans. This report reveals the mechanism by which β-glucan-specific CBMs can distinguish between linear and mixed linked glucans, and show how these CBMs can exploit an extensive hydrophobic platform to target the side chains of decorated β-glucans.     

Evaluation of phytochemical and antimicrobial properties of leaf extract of Tapinanthus sessilifolius (P. Beauv) van Tiegh

Leaf extracts of T. sessilifolius growing on five different host plants (Psidium guajava, Citrus lemon, Vernonia amygdalina, Persea americana and Jatropa curcas) were evaluated for antimicrobial activity of the plant. Powdered leaves of T. sessilifolius collected from each host plant was divided into two portions. One portion was used for aqueous infusion and the other portion was successively extracted with hexane, ethylacetate and methanol. Infusion of aqueous extract of powdered leaves did not show antimicrobial effect even at the concentration of 1000 and 2000 microg/ml on test microorganisms (Staph. aureus, E. coli, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans). However in broth culture, methanolic and hexane extract had MIC range of 62.5-500 microg/ml and ethylacetate extract had 250-500 microg/ml. Phytochemical screening of leaf samples of T. sessilifolius collected from different host plants showed positive test for hydrolysable tannins, saponins, flavonoids, terpenes, cardiac glycoside, reducing sugars and proteins. LD50 concentration was found to be > 1.500 mg/kg for samples from P. guajava; 489.89 mg/kg for J. curcas and C. lemon; and 692 mg/kg for V. amydalina in mice.     

A comparison of two microbial detection methods used in aseptic processing of musculoskeletal allograft tissues

Tissues from 78 musculoskeletal donors were concurrently tested for microorganisms using both a swab and liquid culture method. An aggregate total of 20 organisms were detected by both methods. The swab detected 4/20 organisms while the liquid culture detected 18/20 organisms. The swab method yielded sensitivity and negative predictive values of 20 and 92.3%, respectively. Comparatively, the liquid culture displayed a sensitivity of 90% and a negative predictive value of 99%. These results clearly demonstrate that the liquid culture method is superior to swab cultures in microbial detection. Additional studies are necessary to determine the optimal culture conditions for different types of tissues when utilizing the liquid culture method.     

Effects of predation-risk on habitat use by Himalayan Snowcocks

Summary When given a choice, animals often prefer foraging habitats where predation risk is low, even if such habitats provide reduced foraging opportunities. We evaluated foraging rates of tame but free-ranging Himalayan Snowcocks (Tetraogallus himalayensis) in 16 types of alpine habitats. Foraging rate was highest on level or slightly-sloping terrain and where grasses were relatively abundant. We also observed 102 wild snowcocks and found they were most nervous about raptorial predators when on level or slightly-sloping terrain and in small coveys. Snowcocks face a dilemma: they are most vulnerable to raptors in areas where they can forage most efficiently. During summer snowcocks trade off higher foraging efficiency on level terrain for lower predation risk on steeper terrain. During winter, when raptor numbers are lower, snowcocks apparently revert to using level or slightly-sloping, high-efficiency foraging habitats. Risk of predation plays an important role in habitat selection and resource utilization by snowcocks.     

My Reflections on Understanding Animal Emotions for Improving the Life of Animals in Zoos

ABSTRACT

Scientists are often reluctant to attribute emotions to nonhuman animals that are similar to human emotions. When the author published her early studies, reviewers prohibited the word fear. Fearful behavior had to be described as agitated. The core emotional systems described by Panksepp may provide a useful framework for people who work hands-on with animals. The core systems are fear, rage, panic (separation distress), seek, lust, nurture, and play. Some scientists who deny that animals have real emotions often fail to review important areas of the literature. The areas that are sometimes left out are the effects of psychiatric medications on animals and genetic influences on differences in animal behavior. In both people and animals, genetics has an influence on both fearfulness and novelty seeking. Visualizing the seven core emotional systems as separate volume controls on a music mixing board may help zoo professionals determine the motivation of both normal and abnormal behavior. It may also help them to design more effective environmental enrichments.     

A small intraexonic deletion within the dystrophin gene suggests a possible mechanism of mutagenesis

A case of Duchenne muscular dystrophy is described with an unusual mutation consisting of a 17-bp deletion within exon 47 of the dystrophin gene. The sequences on either side of the deletion have a high degree of intrastrand base complementarity. It is hypothesised that the mechanism generating the deletion may have been the formation of a hairpin loop structure in a single strand of DNA followed by enzymatic degradation at unpaired regions within the loop. Received: 4 January 1997 / Revised: 21 January 1997     

Effects of tibialis anterior vibration on postural control when exposed to support surface translations

The sensory re-weighting theory suggests unreliable inputs may be down-weighted to favor more reliable sensory information and thus maintain proper postural control. This study investigated the effects of tibialis anterior (TA) vibration on center of pressure (COP) motion in healthy individuals exposed to support surface translations to further explore the concept of sensory re-weighting. Twenty healthy young adults stood with eyes closed and arms across their chest while exposed to randomized blocks of five trials. Each trial lasted 8?s, with TA vibration either on or off. After 2?s, a sudden backward or forward translation occurred. Anterior–posterior (A/P) COP data were evaluated during the preparatory (first 2?s), perturbation (next 3?s), and recovery (last 3?s) phases to assess the effect of vibration on perturbation response features. The knowledge of an impending perturbation resulted in reduced anterior COP motion with TA vibration in the preparatory phase relative to the magnitude of anterior motion typically observed during TA vibration. During the perturbation phase, vibration did not influence COP motion. However, during the recovery phase vibration induced greater anterior COP motion than during trials without vibration. The fact that TA vibration produced differing effects on COP motion depending upon the phase of the perturbation response may suggest that the immediate context during which postural control is being regulated affects A/P COP responses to TA vibration. This indicates that proprioceptive information is likely continuously re-weighted according to the context in order to maintain effective postural control.     

Evidence from immunoblotting studies on uncoupling protein that brown adipose tissue is not present in the domestic pig

Adipose tissues and other tissues of the pig have been examined for the presence of the mitochondrial "uncoupling protein," characteristic of brown adipose tissue, in order to assess whether brown fat is present in this species. Mitochondria were prepared from various tissues and the proteins separated on the basis of molecular weight by sodium dodecyl sulphate--polyacrylamide gel electrophoresis. Immunoblotting procedures were then used to probe for uncoupling protein, employing a rabbit anti-(rat uncoupling protein) serum. Pigs were examined at 4 days, 4 weeks, and 8 weeks of age. No evidence for the presence of uncoupling protein was found at any of these ages. The protein was, however, readily detected in brown adipose tissue from rats, mice, golden hamsters, guinea pigs, Richardson's ground squirrel, and lambs. An additional group of pigs was acclimated to the cold (10 degrees C) for a period of 10 days prior to the examination of tissues, but again uncoupling protein was not detected in any tissue. These results indicate that uncoupling protein is either absent from adipose tissues of the pig or is present at such a low concentration that it is unlikely to support thermogenesis. It is concluded that the pig does not contain adipose tissue that is functionally "brown;" adipose tissues in this species appear to be exclusively "white."     

Cloning and partial DNA sequencing of two new human papillomavirus types associated with condylomas and low-grade cervical neoplasia.

Using low-stringency Southern blot analysis and cloning in lambda bacteriophage, two new human papillomavirus types (HPV-43 and HPV-44) were identified and their DNAs were cloned from vulvar tissues. The isolates were characterized by restriction endonuclease mapping and shown to be new HPV types on the basis of their minimal hybridization with all other known HPV types at high stringency. Both HPVs are most closely related to types 6, 11, and 13. HPV-43 did not exhibit any cross-reactivity with these HPV types at high stringency. HPV-44 showed minimal cross-reactivity to HPV-13, which was in the range of 20 to 25% according to liquid hybridization analysis. The deduced genomic organization of each of the two new HPVs was colinear with HPV-6b. Prevalence studies revealed that HPV-43 and HPV-44 together were found in 6 of 439 normal cervical tissues, in 8 of 195 cervical intraepithelial neoplasms, but in none of 56 cervical cancers tested thus far.