<i>Pantoea agglomerans</i>: a marvelous bacterium of evil and good. Part I. Deleterious effects: Dust-borne endotoxins and allergens – focus on cotton dust

Abstract

The ubiquitous Gram-negative bacterium Pantoea agglomerans (synonyms: Enterobacter agglomerans, Erwinia herbicola) is known both as an epiphytic microbe developing on the surface of plants, and as an endophytic organism living inside the plants. The bacterium also occurs abundantly in plant and animal products, in the body of arthropods and other animals, in water, soil, dust and air, and occasionally in humans. From the human viewpoint, the role of this organism is ambiguous -both deleterious and beneficial: on one side it causes disorders in people exposed to inhalation of organic dusts and diseases of crops, and on the other it produces substances effective in the treatment of cancer and other diseases of humans and animals, suppresses the development of various plant pathogens, promotes plant growth, and appears as a potentially efficient biofertilizer and bioremediator. P. agglomerans has been identified as a predominant bacterium on cotton plants grown worldwide, usually as an epiphyte, rarely as pathogen. It is particularly numerous on cotton bract after senescence. During the processing of cotton in mills, bacteria and their products are released with cotton dust into the air and are inhaled by workers, causing respiratory and general disorders, usually defined as byssinosis. The most adverse substance is endotoxin, a heteropolymer macromolecule present in the outermost part of the cell wall, consisting of lipopolysaccharide (LPS) as a major constituent, phospholipids and protein. Numerous experiments carried out in last quarter of 20th century on laboratory animals and human volunteers supported convincing evidence that the inhaled endotoxin produced by P. agglomerans causes numerous pathologic effects similar to those elicited by cotton dust, such as the influx of free lung cells into airways and activation of alveolar macrophages which secrete mediators (prostaglandins, platelet-activating factor, interleukin-1, tumour necrosis factor) that cause the accumulation of platelets in pulmonary capillaries, initiating acute and chronic inflammation, resulting in endothelial cell damage and extravasation of cells and fluids into the lung interstitium. These changes cause bronchoconstriction, the decrement of lung function expressed as reduction of forced expiratory volume in one second (FEV 1 ) and/or diffusion capacity, increase in the airway hyper-reactivity and subjective symptoms such as fever, airway irritation and chest tightness. The conclusions from these experiments, performed mostly 20-30 years ago, did not loose their actuality until recently. This was because to-date no other cotton dust component had been identified as a more important work-related hazard than bacterial endotoxin. Although other microbial and plant constituents are also considered as potential causative agents of byssinosis, the endotoxin produced by Pantoea agglomerans and other Gram-negative bacteria present in cotton dust, is still regarded as a major cause of this mysterious disease. Key wordsPantoea agglomerans, end...

Expression of cerebral serotonin related to anxiety-like behaviors in C57BL/6 offspring induced by repeated subcutaneous prenatal exposure to low-dose lipopolysaccharide

“…We found that an injection of >100 μg/Kg LPS resulted in an abortion in approximately 60–66% of the pregnant mice. Low dose (≤100 μg/Kg) of LPS induces maternal immune activation similar to that of a chronic infection or contact with environmental allergens such as dust [16, 19, 61]. Using low-dose LPS stimulation, the rate of abortion was as low as 11% in this study.…”

<i>Pantoea agglomerans</i>: a mysterious bacterium of evil and good. Part III. Deleterious effects: infections of humans, animals and plants

“…Nevertheless, although the exact data were unless recently unknown, the prevalence of these infections is presumably lower compared to the cases of allergic and/or immunotoxic disorders caused by this bacterium. The latter are much less explored on the world scale, but most probably pose more important medical problems, especially with relation to occupational health [55,120]. P. agglomerans is widespread among invertebrate and vertebrate animals, but its clinical significance in domestic and farm animals is almost unknown.…”

Pantoea agglomerans-Infecting Bacteriophage vB_PagS_AAS21: A Cold-Adapted Virus Representing a Novel Genus within the Family Siphoviridae

“…Plants are usually populated by complex microbial communities composed of algae, fungi, bacteria, and their viruses. The genus Pantoea is one of the predominant taxa in plant microbiomes and comprises both pathogenic and beneficial species that can survive as epiphytes or endophytes on their hosts, but sometimes can cause infections in humans [1,2]. Therefore, bacteriophages could be used as tools for prevention and therapy in both plants and humans or for food preservation [3,4].…”