<< Chapter < Page Chapter >> Page >

Neisseria are cocci that live on mucosal surfaces of the human body. They are fastidious, or difficult to culture, and they require high levels of moisture, nutrient supplements, and carbon dioxide. Also, Neisseria are microaerophilic, meaning that they require low levels of oxygen. For optimal growth and for the purposes of identification, Neisseria spp. are grown on chocolate agar (i.e., agar supplemented by partially hemolyzed red blood cells). Their characteristic pattern of growth in culture is diplococcal: pairs of cells resembling coffee beans ( [link] ).

A photograph showing round domes on a brown background.
Neisseria meningitidis growing in colonies on a chocolate agar plate. (credit: Centers for Disease Control and Prevention)

The pathogen responsible for pertussis ( whooping cough ) is also a member of Betaproteobacteria. The bacterium Bordetella pertussis , from the order Burkholderiales , produces several toxins that paralyze the movement of cilia in the human respiratory tract and directly damage cells of the respiratory tract, causing a severe cough.

[link] summarizes the characteristics of important genera of Betaproteobacteria.

Class Betaproteobacteria
Example Genus Microscopic Morphology Unique Characteristics
Bordetella A small, gram-negative coccobacillus Aerobic, very fastidious; B. pertussis causes pertussis (whooping cough)
Burkholderia Gram-negative bacillus Aerobic, aquatic, cause diseases in horses and humans (especially patients with cystic fibrosis); agents of nosocomial infections
Leptothrix Gram-negative, sheathed, filamentous bacillus Aquatic; oxidize iron and manganese; can live in wastewater treatment plants and clog pipes
Neisseria Gram-negative, coffee bean-shaped coccus forming pairs Require moisture and high concentration of carbon dioxide; oxidase positive, grow on chocolate agar; pathogenic species cause gonorrhea and meningitis
Thiobacillus Gram-negative bacillus Thermophilic, acidophilic, strictly aerobic bacteria; oxidize iron and sulfur
  • What characteristic do all Betaproteobacteria share?

Part 2

When Marsha finally went to the doctor’s office, the physician listened to her breathing through a stethoscope. He heard some crepitation (a crackling sound) in her lungs, so he ordered a chest radiograph and asked the nurse to collect a sputum sample for microbiological evaluation and cytology. The radiologic evaluation found cavities, opacities, and a particular pattern of distribution of abnormal material ( [link] ).

  • What are some possible diseases that could be responsible for Marsha’s radiograph results?
An X-ray showing ribs and other structures as white and the lungs as black. Light white webbings in the lungs are highlighted with white triangles. A dark region in this white webbing is outlined with black arrows.
This anteroposterior radiograph shows the presence of bilateral pulmonary infiltrate (white triangles) and “caving formation” (black arrows) present in the right apical region. (credit: Centers for Disease Control and Prevention)

Jump to the next Clinical Focus box. Go back to the previous Clinical Focus box.

Gammaproteobacteria

The most diverse class of gram-negative bacteria is Gammaproteobacteria , and it includes a number of human pathogens. For example, a large and diverse family, Pseudomonaceae , includes the genus Pseudomonas . Within this genus is the species P. aeruginosa , a pathogen responsible for diverse infections in various regions of the body. P. aeruginosa is a strictly aerobic, nonfermenting, highly motile bacterium. It often infects wounds and burns, can be the cause of chronic urinary tract infections, and can be an important cause of respiratory infections in patients with cystic fibrosis or patients on mechanical ventilators. Infections by P. aeruginosa are often difficult to treat because the bacterium is resistant to many antibiotics and has a remarkable ability to form biofilms. Other representatives of Pseudomonas include the fluorescent (glowing) bacterium P. fluorescens and the soil bacteria P. putida , which is known for its ability to degrade xenobiotics (substances not naturally produced or found in living organisms).

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Microbiology' conversation and receive update notifications?

Ask