Gram Negative Rods

API 20E Test System: Results and Interpretations

API 20E Test System: Results and Interpretations

API-20E test strip (from bioMerieux, Inc.) is used to identify the enteric gram negative rods.

Voges Proskauer (VP) Test: Principle, Procedure, Results

Voges Proskauer (VP) Test: Principle, Procedure, Results

Certain bacteria produce acetoin as the chief end product of glucose fermentation. Acetoin gets oxidized to diacetyl giving red color.

Culture media for Salmonella typhi and paratyphi

Culture media for Salmonella typhi and paratyphi

Common culture media are bismuth sulfite agar, MacConkey agar, deoxycholate citrate agar, xylose lysine deoxycholate agar, salmonella-shigella agar, etc.

Vibrio Cholerae: Characteristics, Pathogenesis, and Lab Diagnosis

Vibrio Cholerae: Characteristics, Pathogenesis, and Lab Diagnosis

Cholera is an acute infection of the gut caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae O1 or O139.

Enterobacteriaceae Family

Enterobacteriaceae Family

Enterobacteriaceae is a family of gram-negative rods which are catalase positive and oxidase negative.

Gram-Positive vs. Gram-Negative Bacteria

Gram-Positive vs. Gram-Negative Bacteria

Gram positive bacteria appear purple and gram-negative bacteria appear pink when stained by Gram-staining methods.

IMViC Tests: Principle, Procedure, Results

IMViC Tests: Principle, Procedure, Results

IMViC is an acronym that stands for four different tests; indole test, methyl red test, Voges-Proskauer test, and citrate utilization test.

Campylobacter Jejuni: Disease, Properties, Lab Diagnosis

Campylobacter Jejuni: Disease, Properties, Lab Diagnosis

The most common cause of gastroenteritis worldwide, Campylobacter is a curved, gram-negative rod. It is an oxidase-positive microaerophile.

Size, Shape, Arrangement of Bacteria

Size, Shape, Arrangement of Bacteria

Bacteria exist in four basic morphologies: cocci; rod-shaped cells, or bacilli; spiral-shaped cells, or spirilla; and comma-shaped cells, or vibrios.

Lipopolysaccharide (LPS) Layer

Lipopolysaccharide (LPS) Layer

Lipopolysaccharide (LPS) layer also called the outer membrane is the outermost layer present in the cell wall of gram-negative bacteria.

Salmonella: Properties, Disease, Lab Diagnosis

Salmonella: Properties, Disease, Lab Diagnosis