Laboratory Diagnosis, Prevention and Treatment of bacterial Infection Xiao-Kui guo
Laboratory Diagnosis, Prevention and Treatment of Bacterial Infection Xiao-Kui Guo
Manifestations of Infection: Signs and symptoms vary according to the site and severity of infection Diagnosis requires a composite of information, including history physical examination, radiographic findings, and laboratory data a Microbial Causes of Infection: Infections may be caused by bacteria, viruses, fungi, and parasites. The pathogen may be exogenous (acquired from environmental or animal sources or from other persons or endogenous (from the normal flora)
Manifestations of Infection: Signs and symptoms vary according to the site and severity of infection. Diagnosis requires a composite of information, including history, physical examination, radiographic findings, and laboratory data. Microbial Causes of Infection: Infections may be caused by bacteria, viruses, fungi, and parasites. The pathogen may be exogenous (acquired from environmental or animal sources or from other persons) or endogenous (from the normal flora)
Specimen Selection, Collection, and Processing I The quantity material must be adequate I Specimens are selected on the basis of signs and symptoms, should be representative of the disease p rocess I Contamination of the specimen must be avoided by using only sterile equipment and aseptic precautions The specimen must be taken to the laboratory and examined promptly. special transport media may be helpful. I Meaningful specimens to diagnose bacterial infections must be secured before antimicrobial drugs are administered
Specimen Selection, Collection, and Processing The quantity material must be adequate Specimens are selected on the basis of signs and symptoms, should be representative of the disease process Contamination of the specimen must be avoided by using only sterile equipment and aseptic precautions The specimen must be taken to the laboratory and examined promptly. Special transport media may be helpful. Meaningful specimens to diagnose bacterial infections must be secured before antimicrobial drugs are administered
Microbiologic Examination Culture: Isolation of infectious agents frequently requires specialized media Nonselective(noninhibitory) media permit the growth of many microorganisms Selective media contain inhibitory substances that permit the isolation of specific types of microorganisms Microbial Identification: Colony and cellular morphology may permit preliminary identification Growth characteristics under various conditions utilization of carbohydrates and other substrates, enzymatic activity, immunoassays, and genetic probes are also used Antimicrobial Susceptibility: Microorganisms, particularly bacteria, are tested in vitro to determine whether they are susceptible to antimicrobial agents Serodiagnosis: A high or rising titer of specific IgG antibodies or the presence of specific IgM antibodies may suggest or confirm a diagnosis 1 Direct Examination and Techniques: Direct examination of specimens reveals gross pathology. Microscopy may identify microorganisms. Immunofluorescence immuno-peroxidase staining, and other immunoassays may detect specific microbial antigens. Genetic probes identify genus-or species-specific DNA or RNA sequences
Microbiologic Examination Culture:Isolation of infectious agents frequently requires specialized media. Nonselective (noninhibitory) media permit the growth of many microorganisms. Selective media contain inhibitory substances that permit the isolation of specific types of microorganisms. Microbial Identification: Colony and cellular morphology may permit preliminary identification. Growth characteristics under various conditions, utilization of carbohydrates and other substrates, enzymatic activity, immunoassays, and genetic probes are also used. Antimicrobial Susceptibility: Microorganisms, particularly bacteria, are tested in vitro to determine whether they are susceptible to antimicrobial agents. Serodiagnosis:A high or rising titer of specific IgG antibodies or the presence of specific IgM antibodies may suggest or confirm a diagnosis. Direct Examination and Techniques: Direct examination of specimens reveals gross pathology. Microscopy may identify microorganisms. Immunofluorescence, immuno-peroxidase staining, and other immunoassays may detect specific microbial antigens. Genetic probes identify genus- or species-specific DNA or RNA sequences
cerd Symptomatic Patient. floeallzod of salamis) Specimen collection Careetoan6a 15F 4 PresuMeS Feses Tie ar Teal aleutian hy elin fierosnnrie Culle Serologic Tecte rene edie se nm l LL耗A Doinili r diagnosis ⊙】m线im o