Limits...
Traditional and molecular techniques for the study of emerging bacterial diseases: one laboratory's perspective.

Houpikian P, Raoult D - Emerging Infect. Dis. (2002)

Bottom Line: Identification of emerging bacterial pathogens generally results from a chain of events involving microscopy, serology, molecular tools, and culture.Because of the spectacular molecular techniques developed in the last decades, some authors think that these techniques will shortly supplant culture.Serology provided indirect evidence for causality.

View Article: PubMed Central - PubMed

Affiliation: Unité des Rickettsies, Faculté de Médecine de Marseille, France.

ABSTRACT
Identification of emerging bacterial pathogens generally results from a chain of events involving microscopy, serology, molecular tools, and culture. Because of the spectacular molecular techniques developed in the last decades, some authors think that these techniques will shortly supplant culture. The key steps that led to the discovery of emerging bacteria have been reviewed to determine the real contribution of each technique. Historically, microscopy has played a major role. Serology provided indirect evidence for causality. Isolation and culture were crucial, as all emerging bacteria have been grown on artificial media or cell lines or at least propagated in animals. With the use of broad-range polymerase chain reaction, some bacteria have been identified or detected in new clinical syndromes. Culture has irreplaceable advantages for studying emerging bacterial diseases, as it allows antigenic studies, antibiotic susceptibility testing, experimental models, and genetic studies to be carried out, and remains the ultimate goal of pathogen identification.

Show MeSH

Related in: MedlinePlus

Diagram describing the respective places of culture-, polymerase chain reaction-, serology- and histology-based approaches for the diagnosis of acute bacterial infections, according to the natural course of the disease. Isolation and culture are possible as long as live bacteria are present in tissues, i.e., from the colonization to the treatment or to the end of the clinical manifestations (or shortly earlier). Bacterial DNA can be detected during the same period and also as far as dead microorganisms remain in tissues. Specific antibodies appear during the clinical course of the disease and persist generally for months or years. Pathologic changes can be observed soon after the contamination and, in an acute infection, will decline rapidly after elimination of the bacteria.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3369584&req=5

Figure 1: Diagram describing the respective places of culture-, polymerase chain reaction-, serology- and histology-based approaches for the diagnosis of acute bacterial infections, according to the natural course of the disease. Isolation and culture are possible as long as live bacteria are present in tissues, i.e., from the colonization to the treatment or to the end of the clinical manifestations (or shortly earlier). Bacterial DNA can be detected during the same period and also as far as dead microorganisms remain in tissues. Specific antibodies appear during the clinical course of the disease and persist generally for months or years. Pathologic changes can be observed soon after the contamination and, in an acute infection, will decline rapidly after elimination of the bacteria.

Mentions: In the last 20 years, advances in knowledge have resulted in a broad expansion of the spectrum of microorganisms regarded as human pathogens. Most advances have evolved in a series of small steps based on several techniques that have been used successively by different investigators who faced clinically suspect diseases. These include the traditional techniques of microscopy, serology, and culture, as well as more recent molecular tools (Figure 1). In addition to aiding in discovering new pathogens, these techniques also contributed to studies of the epidemiology, pathophysiology, and treatment response of the newly recognized diseases, providing further evidence for causal relationships between disease and organism (1). As a diagnostic and research laboratory specializing in fastidious, intracellular bacteria, we have been particularly interested in assessing the specific role played by culture in identifying emerging pathogens. Historical examples, such as Lyme or Legionnaires’ diseases, and recent successes, such as culture of the Whipple bacillus, support the effectiveness of this technique (2). Moreover, culture provided the basis of other supplemental tools to elucidate the causes of microbial disease and to study the clinical and biological features of emerging bacterial diseases. These tools are not only antigenic and serologic assays but also in vitro and in vivo disease models for pathophysiologic studies and antimicrobial susceptibility testing, plus extensive genetic sequencing. The isolation of emerging pathogens serves, therefore, not only as a means for diagnosis but also as a route to enhance understanding of the diversity and epidemiology of emerging bacteria and the infections they cause.


Traditional and molecular techniques for the study of emerging bacterial diseases: one laboratory's perspective.

Houpikian P, Raoult D - Emerging Infect. Dis. (2002)

Diagram describing the respective places of culture-, polymerase chain reaction-, serology- and histology-based approaches for the diagnosis of acute bacterial infections, according to the natural course of the disease. Isolation and culture are possible as long as live bacteria are present in tissues, i.e., from the colonization to the treatment or to the end of the clinical manifestations (or shortly earlier). Bacterial DNA can be detected during the same period and also as far as dead microorganisms remain in tissues. Specific antibodies appear during the clinical course of the disease and persist generally for months or years. Pathologic changes can be observed soon after the contamination and, in an acute infection, will decline rapidly after elimination of the bacteria.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369584&req=5

Figure 1: Diagram describing the respective places of culture-, polymerase chain reaction-, serology- and histology-based approaches for the diagnosis of acute bacterial infections, according to the natural course of the disease. Isolation and culture are possible as long as live bacteria are present in tissues, i.e., from the colonization to the treatment or to the end of the clinical manifestations (or shortly earlier). Bacterial DNA can be detected during the same period and also as far as dead microorganisms remain in tissues. Specific antibodies appear during the clinical course of the disease and persist generally for months or years. Pathologic changes can be observed soon after the contamination and, in an acute infection, will decline rapidly after elimination of the bacteria.
Mentions: In the last 20 years, advances in knowledge have resulted in a broad expansion of the spectrum of microorganisms regarded as human pathogens. Most advances have evolved in a series of small steps based on several techniques that have been used successively by different investigators who faced clinically suspect diseases. These include the traditional techniques of microscopy, serology, and culture, as well as more recent molecular tools (Figure 1). In addition to aiding in discovering new pathogens, these techniques also contributed to studies of the epidemiology, pathophysiology, and treatment response of the newly recognized diseases, providing further evidence for causal relationships between disease and organism (1). As a diagnostic and research laboratory specializing in fastidious, intracellular bacteria, we have been particularly interested in assessing the specific role played by culture in identifying emerging pathogens. Historical examples, such as Lyme or Legionnaires’ diseases, and recent successes, such as culture of the Whipple bacillus, support the effectiveness of this technique (2). Moreover, culture provided the basis of other supplemental tools to elucidate the causes of microbial disease and to study the clinical and biological features of emerging bacterial diseases. These tools are not only antigenic and serologic assays but also in vitro and in vivo disease models for pathophysiologic studies and antimicrobial susceptibility testing, plus extensive genetic sequencing. The isolation of emerging pathogens serves, therefore, not only as a means for diagnosis but also as a route to enhance understanding of the diversity and epidemiology of emerging bacteria and the infections they cause.

Bottom Line: Identification of emerging bacterial pathogens generally results from a chain of events involving microscopy, serology, molecular tools, and culture.Because of the spectacular molecular techniques developed in the last decades, some authors think that these techniques will shortly supplant culture.Serology provided indirect evidence for causality.

View Article: PubMed Central - PubMed

Affiliation: Unité des Rickettsies, Faculté de Médecine de Marseille, France.

ABSTRACT
Identification of emerging bacterial pathogens generally results from a chain of events involving microscopy, serology, molecular tools, and culture. Because of the spectacular molecular techniques developed in the last decades, some authors think that these techniques will shortly supplant culture. The key steps that led to the discovery of emerging bacteria have been reviewed to determine the real contribution of each technique. Historically, microscopy has played a major role. Serology provided indirect evidence for causality. Isolation and culture were crucial, as all emerging bacteria have been grown on artificial media or cell lines or at least propagated in animals. With the use of broad-range polymerase chain reaction, some bacteria have been identified or detected in new clinical syndromes. Culture has irreplaceable advantages for studying emerging bacterial diseases, as it allows antigenic studies, antibiotic susceptibility testing, experimental models, and genetic studies to be carried out, and remains the ultimate goal of pathogen identification.

Show MeSH
Related in: MedlinePlus