A Microbial Biorealm page on the genus Neisseria elongata
Higher order taxa
root; cellular organisms; Bacteria; Proteobacteria; Betaproteobacteria; Neisseriales; Neisseriaceae; Neisseria
Description and significance
Neisseria elongata, formerly known as Centers for Disease Control (CDC) group M6, was described by Bovre and Holten in 1970 as a gram-negative, rod-shaped bacterium of the family Neisseriaceae, where it is found in the oral bacterial flora of the human pharynx and throat (2). N. elongata consists of three subspecies, N. elongata subsp. elongata, N. elongata subsp. glycolytica, and N. elongata subsp. nitroreducens, in which are separated based on their biochemical differences (3). Although these subspecies of N. elongata were previously believed to be nonpathogenic to humans, recent case studies from patients suffering from endocarditis, have indicated that all three N. elongata subspecies are associated with human disease, particularly endocarditis and osteomyelitis (2).
Although the N. elongata genome has not yet been sequenced, the importance of sequencing its genome will provide information on the three N. elongata subspecies that could possibly assist in distinguishing their pathogenic roles in endocarditis and osteomyelitis. Before the pathogenic roles of all three N. elongata subspecies discovered, as N. elongata subsp. nitroreducens was the first subspecies to be discovered as pathogenic, N. elongata subsp. elongata and N. elongata subsp. glycolytica were considered just to be transient colonizers of the human upper respiratory tract and urogentical tract (3). Thus, the sequencing of their genomes could possibly provide further insight into the differences and similarities involved in the factors influencing the metabolism and virulent features of the three N. elongata subspecies.
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?
Cell structure and metabolism
N. elongata is a nonmotile, aerobic, catalase-negative, asaccharolytic, oxidase-positive, urea-negative, gram-negative coccobacilli with complex nutritional requirements. The optimal temperature of growth for N. elongata is 35 degrees Celsius (4). Before the current isolation and characterization of Neisseria bacilliformis from human infections, N. elongata was the only bacillary Neisseria species isolated from humans. The rod-like shape of N. elongata makes it unique from the other Neisseria species, which are either cocci or diplococci (5).
The classification of N. elongata into three different subspecies, N. elongata subsp. elongata, N. elongata subsp. glycolytica, and N. elongata subsp. nitroreducens, is based on their biochemical differences. N. elongata subsp. nitroreducens are different from N. elongata subsp. elongata in their ability to reduce nitrate and sometimes cause a weak acidification of glucose media. N. elongata subsp. nitroreducens are different from N. elongata subsp. glycolytica in their ability to reduce nitrate and in their negative reaction for glucose and catalase (6).
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Enter summaries of the most recent research here--at least three required
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
Edited by student of Rachel Larsen