Burkholderia cepacia

Structure and Physiology

This bacteria is Gram-negative, rod shaped, and capable of growth in a variety of environments including soil, water, animals, and plants. B. cepacia is closely related to Pseudomonas spp. and exhibits several similar morphological characteristics.

Transmission and Disease

Typically identified as a plant and human pathogen, it is known to cause onion bulb rot and is a prevalent cause of infection in individuals with cystic fibrosis.

Neiserria gonorrhoeae

Structure and Physiology

This bacteria is a Gram-negative diplococci.

Transmission and Disease

Neisseria gonorrhoeae is the causative agent of the sexually transmitted infection gonorrhea. This bacteria is capable of transformation and conjugation to spread genes and mutations. This makes it difficult for the immune system to recognize and an area of interest in medical research due to rising antibiotic resistance.

Bordetella pertussis

Structure and Physiology

This bacterium is a Gram-negative, non-motile, coccobacillus aerobe.

Serratia marcescens

Structure and Physiology

This bacteria is a Gram-negative, rod-shaped, facultative anaerobe that has been classified as an opportunistic pathogen for immunocompromised individuals. This bacteria can be commonly found in damp environments like bathrooms, where it manifests as a pink-orange film due to a reddish-orange pigment called prodigiosin.

Transmission and Disease

S. marcescens can be responsible for infections at several sites on the human body including the eyes, urinary tract, and respiratory system.

Legionella pneumophila

Structure and Physiology

This bacteria is a Gram-negative, flagellated aerobe that is nonencapsulated and pleomorphic. L. pneumophila is a facultative, intracellular parasite, meaning that while able to survive and replicate outside of a host, the natural resevoir of this microorganism is inside of free-living, ubiquitous ameoba, where it uses the host as an added barrier to environmental stressors. As an added function to this form of pathogenicity, when white blood cells of the human immune system take up L.

Acinetobacter baumannii

Structure and Phisiology

This bacteria is a Gram-negative, rod-shaped aerobe. A. baumannii can be responsible for infections such as pneumonia and septicemia in immunodeficient patients. The natural reservoir of this organism remains to be determined. These are among a class of bacteria that are "naturally transformable" - meaning that the incorporation of exogenous genetic material can occur due to a special physiological state incorporated by the bacteria, which may be the reason for the prevalence of antibiotic resistance in some strains of A. baumannii.

Enterobacter aerogenes

Structure and Physiology

This bacteria is Gram-negative, rod-shaped, and radially surrounded by flagellum. It can be found in dairy products, soil, and the gastrointestinal tract of animals. E. aerogenes is closely related to a wide range of other common microorganisms including Escherichia, Klebsiella, Shigella, and Serratia.   

Enterobacter cloacae

Structure and Physiology

This bacteria is a Gram-negative, rod shaped, facultative anaerobe commonly found in the gastrointestinal tract of humans. It is not usually a primary pathogen although it is sometimes associated with urinary and respiratory tract infection.

Salmonella enterica

Structure and Physiology

Salmonella enterica is a Gram-negative, rod-shaped, facultative anaerobic bacterium that is common to all parts of the world. S. enterica contains flagella that are used for locomotion and a sensory organelle to measure the chemical nature and temperature of the extracellular space. A characteristic of this bacterium is its ability to create successful biofilms and bind strongly to host cells. It contains a very high level of fimbrial (attachment pili) and non-fimbrial adhesins that allow strong, stable binding.

Escherichia coli

Structure and Physiology

Escherichia coli is a Gram-negative, rod-shaped, facultative anaerobic bacterium that is commonly found in the gastrointestinal tract of warm-blooded animals. Although most serotypes of this organism are harmless inhabitants of the intestinal flora, there are pathogenic strains of E. coli that produce toxins which cause illness in humans.  The harmless strains benefit their host by producing vitamin K2 and prevent potential colonization of pathogenic bacteria.