Streptococcus pneumoniae

Structure and Physiology

This bacteria is Gram-positive, aerotolerant, and spherical-shaped. S. pneumonia is part of the normally occurring flora of the upper respiratory tract.

Transmission and Disease

S. pneumoniae can be responsible for numerous infections including pneumonia, bacteremia, and meningitis.

Disinfection

S. pneumoniae has exhibited susceptibility to several antimicrobial products and is moderately easy to disinfect.

Notes

References

Staphylococcus epidermidis

Structure and Physiology

This bacteria is a Gram-positive, cocci-shaped, facultative anaerobe. S. epidermidis is part of the human bacterial flora, mostly located on skin.

Transmission and Disease

It is not usually pathogenic; however, antibiotic resistant strains have evolved.

Disinfection

Most Staphylococcus species are a hardy microorganisms capable of surviving on surfaces and under dry conditions. This bacteria, specifically, is regularly used in quality control, media testing, and pharmaceutical/personal care products testing.

Staphylococcus aureus (MRSA)

Structure and Physiology

Methicillin-resistant Staphylococcus aureus (MRSA) is a Gram-positive, coccal-shaped, facultative anaerobic bacterium that is responsible for many difficult to treat infections. MRSA is any strain of Staphylococcus aureus that has developed a resistance to beta-lactam antibiotics through the process of natural selection. Beta-lactam antibiotics include penicillin, methicillin, dicloxacillin, nafcillin, oxacillin, and cephalosporins. Resistance does not increase the virulence of the microbe but does make it more difficult to treat.

Enterococcus faecalis (VRE)

Structure and Physiology

Enterococcus faecalis is a Gram-positive, nonmotile, facultative anaerobic microbe.  Vancomycin Resistant Enterococcus (VRE) are strains that are resistant to the antibiotic vancomycin. There are six different types of vancomycin resistance shown by Enterococcus: Van-A, Van-B, Van-C, Van-D, Van-D, Van-E, Van-F. Van-A, Van-B, Van-C have been tested in clinical trials and have shown to be resistant to vancomycin and teicoplanin. The current treatment in the U.S for VRE is linezolid.

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.

Enterococcus faecium

Structure and Physiology

Enterococcus faecium is a Gram-positive, coccal shaped, facultative anaerobic bacterium that can occur in pairs or chains. Its natural habitat includes the gastrointestinal tract, oral cavity, and vaginal tract of a wide variety of animals. The colonies that are produced appear wet and have an average size of 1-2 mm. E. faecium can survive for long periods of time inside hospital, sewage, and soil.

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.