Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
2000-01-11
2001-06-12
Jones, W. Gary (Department: 1655)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C435S006120, C536S024300, C536S023100
Reexamination Certificate
active
06245906
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a probe which is useful for detecting and identifying
Streptococcus pyogenes
, the causative bacteria of infectious diseases such as pharyngitis, rheumatic fever, nephritis, erysipelas, scarlatina, sepsis and the like.
BACK GROUND ART
Generally, the diseases caused by infection of pathogenic microorganisms are called infectious diseases. In pathology, “infection” is defined as an invasion of pathogenic microorganisms (hereinafter referred to as “bacteria”) and an establishment of footholds for the growth in the host organism by the pathogenic microorganisms. Thereafter, the outbreak of the disease states caused by proliferation of the pathogenic microorganisms in vivo depends upon the relationship between the resistance of the host and the virulence of the bacteria.
Streptococcus is a genus of gram-positive facultative or obligate anaerobe, which exhibits the chain like arrangement. According to the characteristic appearances of hemolytic rings formed around the colonies grown on blood agar medium, the member of this genus is classified into three types: &agr;, &bgr;, and &ggr;. Moreover, the members of this genus are further classified into 20 groups from A to V (except I and J) in dependence upon their antigenicity of C-polysaccharide contained in the bacteria (Lancefield classification).
Streptococcus pyogenes
is a member of Streptococcus Group A under Lancefield classification, which shows &bgr;-type hemolysis (i.e., complete hemolysis), and is of clinical importance as causative bacteria of human pharyngitis, tonsillitis, scarlatina, erysipelas, puerperal fever, sepsis and the like. It is also known as the causative bacteria for the allergic diseases which are referred to as post-streptococcal diseases such as rheumatic fever or nephritis secondary to the initial infection. Furthermore, in recent years, the cases that exhibit severe septic shock with myositis (fulminant type Streptococcus Group A infection) due to
Streptococcus pyogenes
infection have been also reported.
The patient suffering from pharyngitis upon
Streptococcus pyogenes
infection generally complains sore throat with significant erythrogenic pharynx and trachelopanus as well as pharyngeal pain, therefore, these clinical symptoms may suggest the infection of the bacteria and lead to the possible diagnosis. However, it is desirable to avoid the unnecessary administration of antibacterial agents while the optimal chemical therapy is extremely important to prevent the complications secondary to the infection, and in view of some cases not accompanied by evident clinical symptoms, development of the rapid and accurate bacteriological diagnosis has been desired.
In addition, in the case of fulminant type Streptococcus Group A infection, more than 50% of the cases were reported to result in complications with severe necrotizing tasciitis, therefore it can be easily progressed to multiple organ failure and even to death.
Streptococcus pyogenes
is generally known to be highly sensitive to &bgr;-lactam agents such as ampicillin and cefaclor. However, approximately 30% of the bacterial strains are highly resistant to erythromycin, and the appearance of ofloxacin resistant strains has also been reported, therefore, the most attention has to be paid at administration with macrolide derivatives or new-quinolone derivatives.
Consequently, it is essentially important to perform the accurate diagnosis at an early stage of infection and select the optimal antibacterial agents in the cases of the infectious diseases caused by
Streptococcus pyogenes
as described above.
In general biological procedure, it is mandatory to: (1) analyze the clinical symptoms; (2) culture the specimen; and (3) isolate and identify
Streptococcus pyogenes
from the cultures, and then the therapeutic strategy is determined after these items are sufficiently examined.
The method to identify
Streptococcus pyogenes
comprises direct smear culturing of the specimen on a blood agar plate which is supplemented with 5% sheep or horse defibrinated blood and monitoring the characteristic appearances of the hemolytic rings around the colonies grown on the plate.
However, it is always accompanied by the difficulties in the identification of the causative bacteria. Actual identification of the causative bacteria is quite difficult because of a variety of shapes of the colonies which are formed dependent upon the culture conditions, thus, the identification is avoided. Also, the bacteria from the specimen have to be proliferated for a long time in the appropriate medium to the number large enough for applying the drug sensitivity test, and then at least 3 to 4 days of incubation period is required to attain the result of the test. Thus the rapid diagnosis can not be achieved in accordance with the above process. Additionally, in cases of the diagnosis of the patients who had already been treated with a large dose of antibiotics when the possible infection was suspected, the growth and proliferation of the bacteria may be prevented even if the bacteria are present in the specimen. Accordingly, the feasibility of successful culture of the bacteria from these specimen may become extremely low.
Furthermore, alternative subroutine methods developed heretofore may include: an instrumental analysis method of constituents of bacteria and metabolic products from bacteria (See Yoshimi Benno, “Quick identification of bacteria with gas chromatography”, Rinsho Kensa, Vol. 29, No.12 pp.1618-1623, November 1985, Igaku Shoin.); a method utilizing a specific antibody (See Japanese Patent Provisional Publication No.60-224068.); and a hybridization method utilizing a specificity of DNA (Japanese Patent Provisional Publication No. 61-502376), however, any of which requires the steps for isolation of the bacteria, as well as the steps for culturing and growing the bacteria.
On the other hand, an established method based on the function of the phagocyte in the infectious diseases has been proposed, wherein a stained smear of buffy coat in which leukocytes constituents in the blood sample are concentrated is examined under an optical microscope. Generally speaking, the detection rate of bacteria in buffy coat specimens from adult bacteremia patients is 30% at most, which is similar to that in blood specimens from ear lobes, however, it was reported that in case that the patients are newborn children, the bacteria could be detected in seven cases in ten (70%). Therefore, information concerning the presence of bacteria in peripheral blood obtained by a microscopic prospection on a smear can provide an important guiding principle for the therapeutic treatment.
The above mentioned conventional methods necessitate the pretreatment which requires at least three to four days in total, containing one to two days for the selective isolation of bacteria from a specimen, one day for proliferating cultivation, and one or more days for operation of fixation, and the culture thereof should be continued in practice until the bacteria grow enough, therefore, the pretreatment may require one week or more days. In addition, any bacteria other than the causative bacteria may be contaminated during the culture step in some cases, and such contaminants may not be distinguished from the causative bacteria.
More importantly, as mentioned above, because many of the causative bacteria in the specimen to be proliferated and detected have been uptaked into phagocytes, and are already dead or in a bacteriostatic state due to the antibiotics administered, the number of bacteria that can be grown may be small even under appropriate conditions for the culture of the causative bacteria, thereby, the actual detection rate of bacteria is as low as about 10% when the clinical culture specimen is employed. In the other words, for the present, 90% of the examined blood from the patient clinically suspected as suffering from the infection of
Streptococcus pyogenes
could not be identified for the presence of the bacteria after all, even though the culture
Abe Kanako
Keshi Hiroyuki
Matsuhisa Akio
Ueyama Hiroshi
Fuso Pharmaceutical Industries Ltd.
Goldberg Jeanine
Jones W. Gary
Marshall O'Toole Gerstein Murray & Borun
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