Fine Structure of Rickettsia quintana Cultivated In Vitro and in the Louse

Abstract

structure of Rickettsia quintana cultivated in vitro and in the louse. J. Bacteriol. 89: 481-495. 1965.-Usually rod-shaped, Rickettsia quintana cells measure about 0.2 to 0.5 , wide and up to 1.6 IA long. The rickettsiae have both an outer cell wall, about 80 A thick, and a plasma membrane, about 70 A thick, each of which is trilaminar. Occasional vesicular invaginations of the plasma membrane occur. The nuclear material, distributed in irregular zones throughout the cytoplasm, appears as a loose network of fine fibrils when postfixed with uranyl acetate and as thick strands or clumps after routine OS04 fixation. The cytoplasm is densely packed with numerous granules, presumably ribosomes, about 150 A in diameter. Histochemical studies revealed the presence of both ribonucleic and deoxyribonucleic acids. During binary fission, a constricting furrow is formed by the cell wall and plasmalemma. No difference in fine structure was observed between R. quintana propagated on cell-free media and in the louse. Rickettsiae constitute a grotul) of microorganisms regarded as intermediate between bacteria and viruses. Although their morphological and physiological characteristics more closely resemble those of certain bacteria, they depend, like viruses, on living host cells for their multiplication. With the exception of Rickettsia quintana, rickettsiae are obligatory intracellular parasites. R. quintana, the etiological agent of trench fever, multiplies extracellularly in the gut of its arthropod vector, Pediculus humanus var. corporis (Wolbach, Todd, and Palfrey, 1922); and, recently, Vinson and Fuller (1961) and Vinson, Varela, and Molina (in preparation) reported the cultivation of R. quintana on cell-free media, as well as in lice, in cells cultivated in vitro, and in the yolk sac of the developing chick embryo. Although studies on the fine structure of several rickettsiae have been reported by various investigators (

Comparison of the Ultrastructure of Several Rickettsiae, Ornithosis Virus, andMycoplasmain Tissue Culture

“…The organisms were free in the cytoplasm of the host cell, were usually cylindrical in shape, were bounded by a cell wall and plasma membrane, and each contained ribosomes and DNA strands. These findings are in agreement with previously published electron micrographs of thin-sectioned R. mooseri (Wissig et al, 1956), R. tsutsugamushi (Schaechter et al, 1957b), and R. quintana (Ito and Vinson, 1965). Tanaka and Hanaoka (1961) described the intravacuolar position of R. sennetsu and suggested that all rickettsiae are similarly located.…”

“…These structures tended to be rippled, which may in part represent shrinkage during the preparative procedures. The plasma membrane was sometimes invaginated, forming small pockets as observed by Ito and Vinson (1965) in studies with R. quintana. The individual rickettsiae were 0.3 to 0.5 , in diameter, and when sectioned longitudinally they were of varying lengths, some as long as 4, (Fig.…”

Role of Erythrocytes and Serum in the Nutrition of Rickettsia quintana

“…Identity of organism grown in hemin-starch Hquid medium. The organisms which grew in the hemin-starch liquid medium, when examined in stained smears, conformed in size, shape, and tinctorial properties to the published descriptions of R. quintana (4) and were identical, in these characteristics, to the organisms originally obtained from Vinson. Moreover, when used as antigen in the complement fixation test, they reacted to titer with specific anti-R. quintana rabbit serum furnished by Vinson (9) and did not fix complement with normal rabbit serum.…”

Comparison of the proliferation and excretion of Bartonella quintana between body and head lice following oral challenge

“…Given that B. quintana cannot pass through alimentary tract tissue and remain in the gut lumen or attached to the surface of epithelial cells (Ito & Vinson, 1965), it can be postulated that the cellular immune response is less important and that the humoral immune response in the alimentary tract is the primary immune factor against invading pathogenic bacteria following an infected bloodmeal. To elucidate what molecular factors may be associated with the different excretion patterns of viable B. quintana in body vs. head lice, the transcriptional profiles of six major humoral immune-related genes in alimentary tract tissue were determined following oral challenge by B. quintana.…”

“…Recently, it was reported that B. quintana was detected from 33.3% of the body lice recovered from the homeless in California, suggesting that B. quintana is still prevalent in the human population (Bonilla et al, 2009). Once B. quintana is introduced into the gut of a louse by blood feeding on an infected patient, the bacteria replicate, colonize and attach to the surface of epithelial cells of the alimentary tract (Ito & Vinson, 1965). Lice have a behaviour of excreting urine and faeces during feeding and viable B. quintana in louse faecal matter can be transferred to the human blood stream via scratches or wounds in the skin.…”