微生物学技术

Aminoglycosides have been cinically used since 1944. Although this class of antibacterial agents has some nephrotoxicity and ototoxtcity issues, they continue to be part of the hospital armamentarium because of then rapid bactericidal activity, especially in combination with β- ...

The widespread use, or perhaps overuse, of penicillin during the past 50 yr has driven the evolution of resistance to penicilling in numerous different species of bacteria.Typically, resistance has arisen as a result of the acquisition of β-lactamases that inactivate the antibiotic (see ...

For the last 20 yr thin-layer polyacrylamide isoelectric focusing (IEF) has played a major role in the identification and characterization of β-lactamases. IEF is able to distinguish enzymes that focus only 0.05 pI apart (1), but the exponential increase rin the numbers of β-lactamases disco ...

Bacterial plasmids are extra-chromosomal, covalently-closed circular (CCC) molecules of DNA that are capable of autonomous replication (1). Plasmids may contain genes for a variety of phenotypic traits, such as antibiotic resistance, virulence, or metabolic activities, altho ...

Enterococci are components of the normal bowel flora of humans and other animals, and have traditionally been considered to be of relatively low virulence in healthy individuals. However, they are increasingly important nosocomial pathogens and have been cited as the leading organism ...

Staphylococcus aureus and coagulase-negative species of staphylococci (CNS), particularly S epidermidis, are among the most frequently isolated bacteria from patients with nosocomial infection. Conventional methods used in the clinical microbiology laboratory for id ...

Helicobacter pylori is a curved mlcroaerobic bacterium that was first lsolated from human antral gastric biopsy material in 1982 by Marshall and colleagues in Perth, Western Australia (1). Since then, enormous interest has developed in the micro-organism that now appears to be one of the most ...

Campylobacters are the most frequently identified cause of acute bacterial diarrhea in humans in England and in many other developed countries. Although C jejuni and C coli are numerically the most important species in cases of campylobacter enteritis, there is a growing awareness that so ...

Although most Escherichia coli are harmless commensals of the human intestine, certain specific, highly-adapted E. coli strains are capable of causing urinary tract, systemic or enteric/diarrheagenic infection. Diarrheagenic E coli are divided into six distinct categories, or p ...

Few diseases invoke public fear as readily as cholera. In its most severe state, cholera can cause death from hypotensive shock within 12 h of the first symptom. Cholera typically occurs in epidemics, spreading rapidly within the community, especially if hygeinic conditions are poor. Fortun ...

Disease caused by any member of the genus Salmonella is termed salmonellosis. The type of disease and its symptoms are generally related to the mfecting species and reflect the invasiveness and virulence of the organism. For example, enteric fevers are systemic diseases usually resulting ...

Organisms of the class Mollicutes (meaning soft-skin) have regressively evolved, by genome reduction, from Gram-positive bacterial ancestors, namely certain clostria (1). The taxonomy of the class Mollicutes, containing four orders, five familes, and eight genera, is shown in Table 1 ( ...

Chancroid is a genital ulcerative disease GUD). These diseases are common throughout the world and include syphilis, genital herpes, chancroid, lymphogranuloma venereum, and donovanosis. Chancroid is particularly common an Africa, Asia, and Latin America where its incidence may e ...

Gonorrhea is a major sexually transmitted disease (STD) that occurs worldwide. The prevalence has fallen dramatically in most industrialized countries in the last ten years because of effective therapy, contact tracing, and changes in sexual practices since the advent of the Acquired I ...

Neisseria meningitidis, the meningococcus, is normally a harmless commensal bacterium that colonises the naso/oropharynx of humans. This antigenically variable gram-negative diplococcus has the potential, however, to cause rapidly progressing meningitis and fulmina ...

The speciesHaemophilus influenzae belongs to the genus Haemophilus and the family Pasteurellaceae. H influenzae are small, nonmotile, nonspore forming, Gram-negative, pleomorphic rods that range in shape from coccobacilli to long filaments. They require X and V factors (hemin and ...

The Legionnaires’ Disease (LD) Bacillus was first recognized following a large outbreak of pneumonia at a convention of American military veterans in 1976 (1). In the context of other microbial infections, this is a relatively recent event. Since then, considerable progress has been made in t ...

Prior to the late 1980s diphtheria was regarded in many countries as one of “those rare and forgotten” diseases associated with the preimmunization era of the 1940s. Despite the success of many immunization programs, there is still much to be learned about this disease that has made a dramatic “ret ...

Bacteria may need to be characterized for a number of reasons. Newly discovered organisms are characterized to determine their taxonomic position; clinical isolates are characterized to provide an indication of pathogenic potential and likely antibiotic susceptibility. Such ...

The genus Mycobacterium consists of a diverse group of organisms that are ubiquitous and are believed to be some of the oldest bacteria on earth. They may exist as free-living commensals inhabiting soil and water, but they are also potentially pathogenic to man and other animals, being transmitt ...