Aug

24

Morgellons: Growth Captured

August 24, 2008 | Comments Off

From Here :

A time lapse video under the microscope has been developed which demonstrates the cultured growth pattern and behavior of a primary pathogenic form that is in direct association with the so-called “Morgellons” condition.

The general public appears to be subject to the conditions that are shown in this report.

Aug

20

From Here :

Lifestyle Evolution in Alpha-Proteobacteria

Interestingly, species from a group called Ochrobactrum, which is most closely related to Brucella has been isolated from an astonishing number of different sources…..For example, Ochrobactrum is frequently isolated from Humans for which it is considered an opportunistic pathogen.

Moreover, two species have been shown to form associations with the nematode pathogen and insect - symbiont P. Luminescens in its nematode host…and another is a nitrogen fixing symbiont of Anaplasma……Ochrobactrum species have been described as free living, but since the majority of isolates are from patients, and since most environmental strains are from the Rhizosphere, this description may not be entirely correct…

Other related species of Alpha-Proteobacteria include :

Bartonella, Brucella, Ochrobactrum, Mesorhizobium, Agrobacterium, Sinorhizobium, Rhodopseudomonas, Bradyrhizobium, Gaulobacter, Rickettsia, Wolbachia, Anaplasma and Erlichia

Aug

19

Ochrobactrum anthropi pseudobacteraemias

August 19, 2008 | Comments Off

From here :

Ochrobactrum anthropi pseudobacteraemias

About 95 blood isolates of Ochrobactrum anthropi have been referred for identification and/or typing over the past two years, originating from 30 hospitals in England and Wales.
Ochrobactrum anthropi is an oxidase-positive, motile, non-lactose fermenting Gram-negative bacillus, formerly known as Achromobacter sp.
It is normally found in the natural environment, sometimes acting as an opportunist pathogen in humans. About 40 of the isolates from nine of the referring hospitals were indistinguishable on pulsed-field gel electrophoresis (PFGE). No other PFGE profile was seen in more than one hospital, although there were 20 different distinguishable patterns for the other isolates of O. anthropi. Most, if not all, of the indistinguishable isolates were of doubtful clinical significance and appear to be pseudobacteraemias, often occurring in patients who were otherwise very ill.
This can clearly have an impact on the management of these patients. More than one blood culture system has been involved.
The Communicable Disease Surveillance Centre (CDSC) and Central Public Health Laboratory (CPHL) have been asked to investigate these apparent pseudobacteraemia incidents in order to identify any potential source of contamination. It would be helpful if microbiologists could discuss any further testing for possible O. anthropi pseudobacteraemia isolates with Polly Kaufmann from the Laboratory of Hospital Infection, Central Public Health Laboratory, Colindale (tel 020 8200 4400 ext 4205 email PKaufmann@phls.org.uk).

In some instances these organisms have been mis-identified as Pseudomonas stutzeri or Stenotrophomonas maltophilia, and they have also sometimes been found in mixed culture with S. maltophilia.

Aug

19

From here :

AFLP was used to analyze the genetic diversity among Ochrobactrum strains. AFLP patterns showed a great genomic variability that separated the samples into three distinct clusters.

Ochrobactrum intermedium was found to be closely related to Brucella abortus S99.

Ochrobactrum spp. are potential human pathogens. Ochrobactrum anthropi bacteremia is usually associated with contaminated intravenous lines in immunocompromised human patients, water sources, and environmental conditions in hospitals (1, 5, 8, 10, 11). O. anthropi isolates have also recently been obtained from other sources such as water, concrete, soils, termites, feces, activated sludges, oil spills, etc. Many of these isolates present interesting degradative properties not only towards multiple antibiotics but also towards herbicides, hemicellulose, anthracene, and other complex organic molecules including crude oil (2-5, 8, 12, 15, 17, 19, 25), displaying an opportunism that allows them to succeed in a wide range of environments.

Aug

19

Ochrobactrum spp. are human opportunist pathogens

August 19, 2008 | Comments Off

From Here :

Bacteria naturally associated with the symbiont Photorhabdus luminescens subsp. akhurstii were isolated from the entomopathogenic nematode Heterorhabditis indica. Bacterial isolates distinct from P. luminescens subsp. akhurstii were obtained from 33% of the samples. Fourteen bacterial isolates, from nematodes collected from three different Caribbean islands, were characterized by conventional phenotypic tests, restriction fragment length polymorphism and sequence analyses of PCR-amplified 16S rRNA genes (16SrDNAs).
Isolates were grouped into three genotypes, each one being associated with one Caribbean island. Phenotypic characteristics and 16S rDNA analysis showed that the Photorhabdus-associated bacteria were closely related to Ochrobactrum anthropi for the group from Guadeloupe, and to Ochrobactrum intermedium for the two groups from the Dominican Republic and Puerto Rico. No pathogenicity of the Ochrobactrum spp. to the insects Galleria mellonella and Spodoptera littoralis (Lepidoptera) was detected.
Since Ochrobactrum spp. are considered as human opportunist pathogens, the mass production of entomopathogenic nematodes for biological control requires strict vigilance.

Aug

19

From Here :

Bacillus anthracis is an endospore-forming bacterium that causes inhalational anthrax. Key virulence genes are found on plasmids (extra-chromosomal, circular, double-stranded DNA molecules) pXO1 (ref. 2) and pXO2 (ref. 3). To identify additional genes that might contribute to virulence, we analysed the complete sequence of the chromosome of B. anthracis Ames (about 5.23 megabases). We found several chromosomally encoded proteins that may contribute to pathogenicity–including haemolysins, phospholipases and iron acquisition functions–and identified numerous surface proteins that might be important targets for vaccines and drugs. Almost all these putative chromosomal virulence and surface proteins have homologues in Bacillus cereus, highlighting the similarity of B. anthracis to near-neighbours that are not associated with anthrax. By performing a comparative genome hybridization of 19 B. cereus and Bacillus thuringiensis strains against a B. anthracis DNA microarray, we confirmed the general similarity of chromosomal genes among this group of close relatives. However, we found that the gene sequences of pXO1 and pXO2 were more variable between strains, suggesting plasmid mobility in the group. The complete sequence of B. anthracis is a step towards a better understanding of anthrax pathogenesis.

Aug

19

Glowing Insect Bug - Harms Humans

August 19, 2008 | Comments Off

From Here :

A new disease has been identified caused by a luminous bug that has evolved in insects, scientists say.
There have been about a dozen cases of the bug - Photorhabdus asymbiotica - in the US and Australia, which causes pustulant sores to appear on the body.

In insects, the disease leaves the bodies glowing, the University of Bath and London School of Hygiene and Tropical Medicine scientists said.

They are now warning more insect bugs may mutate to threaten humans.

Aug

19

Nematode Symbiont for Photorhabdus asymbiotica

August 19, 2008 | Comments Off

From Here :

Photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the United States and Australia.

Although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus Heterorhabditis.

From Here :
Photorhabdus are the only known terrestrial bioluminescent bacteria. Most members of the Photorhabdus are however insect pathogens that live in a strict symbiotic relationship within the guts entomopathogenic Heterorhabditid nematodes. Infective juvenile nematodes search in the soil for insect prey until they encounter a suitable host. They then scratch their way into the insect’s hemocoel (an “open” blood system ) and “vomit” up Photorhabdus cells directly into the blood. The Photorhabdus then set up a lethal septicemia, secreting toxins and virulence factors that rapidly kill the insect host. The bacteria replicate rapidly and bio-convert the insect tissues into more bacteria that serve as a food source for the reproducing nematodes. It is around the time of insect death that the bioluminescence of the insect corpse can be seen.

Aug

18

From Here :
Bacillus cereus also can cause local skin and wound infections, ocular infections, fulminant liver failure, and invasive disease, including bacteremia, endocarditis, osteomyelitis, pneumonia, brain abscess, and meningitis.
Ocular involvement includes panophthalmitis, endophthalmitis, and keratitis.

Aug

18

Outbreak of Cutaneous Bacillus Cereus Infections

August 18, 2008 | Comments Off

From Here :

The findings in this report indicate that immunocompetent persons can be vulnerable to cutaneous B. cereus infections when skin is compromised. Isolation of three indistinguishable B. cereus isolates from three patients on two separate days suggested that this was a common-source outbreak and not a laboratory contaminant, even though the environmental source of B. cereus was not identified during the investigation. All but five cases were diagnosed on two concurrent days, making person-to-person transmission unlikely. Transmission most likely occurred from an exposure at the beginning of the orientation week. The short haircut likely caused microabrasions, compromising the protective effect of scalp epidermis. Exposure to mud, sun, and sunscreen further provided an environment suitable for bacterial growth.

Aug

18

Bacillus Cereus

August 18, 2008 | Comments Off

From Here :

Bacillus cereus is a Gram-positive, facultatively aerobic sporeformer whose cells are large rods and whose spores do not swell the sporangium. These and other characteristics, including biochemical features, are used to differentiate and confirm the presence B. cereus, although these characteristics are shared with B. cereus var. mycoides, B. thuringiensis and B. anthracis. Differentiation of these organisms depends upon determination of motility (most B. cereus are motile), presence of toxin crystals (B. thuringiensis), hemolytic activity (B. cereus and others are beta hemolytic whereas B. anthracis is usually nonhemolytic), and rhizoid growth which is characteristic of B. cereus var. mycoides.

In the past decade, outbreaks of human illness associated with the consumption of raw vegetables and fruits (or unpasteurized products produced from them) have increased in the United States. Pathogens such as Listeria monocytogenes, Clostridium botulinum, and Bacillus cereus are naturally present in some soil, and their presence on fresh produce is not rare. Salmonella, Escherichia coli O157:H7, Campylobacter jejuni, Vibrio cholerae, parasites, and viruses are more likely to contaminate fresh produce through vehicles such as raw or improperly composted manure, irrigation water containing untreated sewage, or contaminated wash water. Treatment of produce with chlorinated water reduces populations of pathogenic and other microorganisms on fresh produce but cannot eliminate them. Reduction of risk for human illness associated with raw produce can be better achieved through controlling points of potential contamination in the field; during harvesting; during processing or distribution; or in retail markets, food-service facilities, or the home

Aug

17

From Here :

The pathogenesis of Staphylococcus epidermidis is correlated with biofilm formation. We investigated the effect of three common alcoholic skin disinfectants, ethanol, n-propanol and isopropanol, on the biofilm formation of 37 clinical, icaADBC-positive S. epidermidis isolates. In alcohol-supplemented media 18 strains displayed increased biofilm expression. Sixteen of 19 strains were generally incapable of biofilm formation. In three representative isolates, the increase in biofilm formation was paralleled by increased polysaccharide intercellular adhesin synthesis. Regarding the widespread use of alcoholic skin disinfectants, it is possible that the alcohol-inducible biofilm phenotype of S. epidermidis could add to the development of foreign body-related infections

Aug

15

Cercarial Dermatitis

August 15, 2008 | Comments Off

From Here :
Avian schistosomes are the primary causative agent of cercarial dermatitis in humans, but despite its worldwide occurrence, little is known of the immune mechanism of this disease. Using a murine model, hosts were exposed to primary (1x) and multiple (4x) infections of Trichobilharzia regenti via the pinna. Penetration of larvae into the skin evoked immediate edema, thickening of the exposure site, and an influx of leukocytes, including neutrophils, macrophages, CD4+ lymphocytes, and mast cells.

From Here :

More research from the Czech Republic indicating that this problem may be more widespread and damaging to humans and other mammals than at first thought.

Horák P, Kolárová L, Adema CM.
Department of Parasitology, Charles University, Vinicná 7, CZ-12844 Prague 2, Czech Republic.

Trichobilharzia is the largest genus within the family Schistosomatidae, covering over 40 species of avian parasites. To clarify the existing confusion in the systematics of the genus, we recommend combining knowledge of life cycles and developmental stages, snail/bird hosts, cytogenetical and molecular data together with morphological criteria for the characterization of particular species. The high specificity of Trichobilharzia for the intermediate host is a likely reflection of the ability to avoid the internal defence of specific snails. The spectrum of final hosts (birds) seems to be much wider. The infection of birds–trichobilharziasis–may lead to considerable tissue injuries, caused by eggs of the parasite or migration of immature/mature worms through the body. Most Trichobilharzia (visceral species) migrate through the viscera of the host, but nasal species display a neurotropic mode of migration. Due to a low specificity of penetrating cercariae, mammals (including humans) can be attacked. This leads to cercarial dermatitis, predominantly in sensitized hosts. Experimental infections indicate that Trichobilharzia never mature in an incompatible (mammalian) host. However, not all cercariae and schistosomula are necessarily trapped and eliminated in the skin, and parasites may migrate throughout the viscera and the nervous system of mammals. These findings suggest that the pathogenicity of Trichobilharzia may have been underestimated in the past and health risks associated with trichobilharziasis need to be studied further.

Aug

7

Bacillus Subtilis Macrofibers

August 7, 2008 | Comments Off

Abstract : From Here

Growing Bacillus subtilis macrofibers use twist and supercoiling to: power their own selfassembly, join fibers together into multiclonal aggregates, move themselves over solid surfaces, and to drag 2 other structures (cargo) over solid surfaces.
The dragging of multiclonal aggregates attached to the ends of growing macrofibers is analyzed here. The linkage between fibers and cargo arose naturally in macrofiber cultures. Dragging was triggered when growing macrofibers became linked to cargo at both of their ends.
Such macrofibers supercoiled, reduced their length, and dragged the cargo toward one another. In parallel experiments immobile wire was used in place of cargo at one end of macrofibers that were linked to cargo at the other. The cargo was dragged toward the wire when these fibers supercoiled. To estimate the force required for dragging we determined the dimensions of the cargo, the buoyant density of macrofibers in the growth medium where dragging occurred, the rate and distance over which the aggregate structures were dragged, and the viscosity of the growth medium. Friction resulting from contact with the solid surface over which the structures were dragged was estimated using the measured parameters. The results indicate that the supercoiling tension required to overcome limiting friction must have been approximately 10 nN, while that needed to overcome fluid drag was of the order of 1 nN. These values suggest that only a small fraction of the total power available from macrofiber supercoiling was needed to drive this new form of multicellular bacterial movement.
Keywords: Macrofibers; Supercoiling forces; Dragging over surfaces; Bacillus subtilis

August 2008
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