E. coli- Pathogenicity and Clinical Manifestations

E. coli- Pathogenicity and Clinical Manifestations

E. coli is the most common and important member of the genus Escherichia. It is a Gram-negative, facultative anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Human Escherichia coli strains are classified as commensal microbiota E. coli, enterovirulent E. coli, and extraintestinal pathogenic E. coli on the basis of their genetic features … Read moreE. coli- Pathogenicity and Clinical Manifestations

E. coli- Lab Diagnosis, Treatment, Prevention and Control

E. coli- Lab Diagnosis, Treatment, Prevention and Control

Laboratory Diagnosis Urinary Tract Infection Most urine specimens are obtained from adult patients via the clean-catch midstream technique. Bacteriuria can be detected microscopically using Gram staining of uncentrifuged urine specimens, Gram staining of centrifuged specimens, or direct observation of bacteria in urine specimens. On staining, E coli appear as non-spore-forming, Gram-negative rod-shaped bacterium Routine urine … Read moreE. coli- Lab Diagnosis, Treatment, Prevention and Control

Enteroinvasive E. coli (EIEC)

Enteroinvasive E. coli (EIEC)

Enteroinvasive E. coli (EIEC) Enteroinvasive E. coli (EIEC) strains are rare in both developed and developing countries. EIEC infections are characterized by a period of watery diarrhea that precedes the onset of scanty dysenteric stools containing blood and mucus. Pathogenic strains are primarily associated with a few restricted O serotypes: O124, O143, and O164. EIEC … Read moreEnteroinvasive E. coli (EIEC)

CHROMagar (Rambach Agar)

CHROMagar (Rambach Agar)

CHROMagar (Rambach Agar) The first chromogenic culture medium for detection of E. coli was invented and patented by Dr. A. Rambach in 1979. This technology is color-based differentiation method. It is based on soluble colorless molecules (called chromogens), composed of a substrate (targeting a specific enzymatic activity) and a chromophore. When the target organism’s enzyme … Read moreCHROMagar (Rambach Agar)

Enteroaggregative E. coli (EAEC)

Stages of pathogenesis of EAEC

Enteroaggregative E. coli (EAEC) Enteroaggregative E.  coli (EAEC) are a heterogeneous collection of strains characterized by their autoagglutination in a “stacked-brick” arrangement over the epithelium of the small intestine and, in some cases, the colon. EAEC strains are currently defined as  E. coli strains that do not secrete enterotoxins LT or ST and that adhere to HEp-2 … Read moreEnteroaggregative E. coli (EAEC)

E. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC

E. coli Pathotypes

E. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC Escherichia coli (commonly abbreviated E. coli) is a Gram-negative, facultative anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Human Escherichia coli strains are classified as commensal microbiota E. coli, enterovirulent E. coli, and extraintestinal pathogenic E. coli (ExPEC) on the basis of their genetic features … Read moreE. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC

Recombinant DNA Technology- Steps, Applications and Limitations

Recombinant DNA technology

Recombinant DNA Technology- Steps, Applications and Limitations Recombinant DNA technology refers to the joining together of DNA molecules from two different species that are inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry. Recombinant DNA (rDNA), on the other hand is the general name for a piece of DNA that … Read moreRecombinant DNA Technology- Steps, Applications and Limitations

Rapid Method for Enumeration of E. coli Biotype I

Rapid Method for Enumeration of E. coli Biotype I

This method is modified by Anderson and Parker. Prepare serial tenfold dilutions in peptone water of food. Aseptically transfer sterile cellulose acetate membranes to the surface or dried glutamate agar. Transfer duplicate 1.0 mL aliquots of each dilution to cellulose acetate membranes, using a sterile glass Drigalski spreader, distribute the fluid over the entire membrane … Read moreRapid Method for Enumeration of E. coli Biotype I

Biochemical Test of Escherichia coli (E. coli)

Biochemical Test of Escherichia coli (E. coli)

Biochemical Test of Escherichia coli (E. coli) Basic Characteristics Properties (E. coli) Capsule Capsulated Catalase Positive (+ve) Citrate Negative (-ve) Coagulase Negative (-ve) Flagella Flagellated Gas Positive (+ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Negative (-ve) Growth in KCN Negative (-ve) H2S Negative (-ve) Hemolysis Negative (-ve) Indole Positive (+ve) Motility Motile MR (Methyl Red) … Read moreBiochemical Test of Escherichia coli (E. coli)