Sunday, April 22, 2012

STREPTOCOCCUS

Streptococcus
Scientific classification
Kingdom: Bacteria
Phylum: Firmicutes
Class: Coccus[1]
Order: Lactobacillales
Family: Streptococcaceae
Genus: Streptococcus
Rosenbach, 1884
Species
S. agalactiae
S. anginosus
S. bovis
S. canis
S. constellatus
S. dysgalactiae
S. equinus
S. iniae
S. intermedius
S. mitis
S. mutans
S. oralis
S. parasanguinis
S. peroris
S. pneumoniae
S. pyogenes
S. ratti
S. salivarius
S. salivarius ssp. thermophilus
S. sanguinis
S. sobrinus
S. suis
S. uberis
S. vestibularis
S. viridans
S. zooepidemicus


Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes[2] and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning easily bent or twisted, like a chain (twisted chain). Contrast this with staphylococci, which divide along multiple axes and generate grape-like clusters of cells. Most streptococci are oxidase- and catalase-negative, and many are facultative anaerobes.
In 1984, many organisms formerly considered Streptococcus were separated out into the genera Enterococcus and Lactococcus.[3]

Pathogenesis

Streptococcal classification.
In addition to streptococcal pharyngitis (strep throat), certain Streptococcus species are responsible for many cases of meningitis, bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are nonpathogenic. Indeed, streptococci are a necessary ingredient in Emmentaler ("Swiss") cheese. Streptococci are also part of the normal commensal microbiome of the mouth, skin, intestine, and upper respiratory tract of humans.
As a rule, individual species of Streptococcus are classified based on their hemolytic properties.[4] Alpha hemolysis is caused by an oxidation of iron in hemoglobin, giving it a greenish color on blood agar. Beta hemolysis is complete rupture of red blood cells, giving distinct, wide, clear areas around bacterial colonies on blood agar. Other streptococci are labeled as gamma-hemolytic, actually a misnomer, as no hemolysis takes place.
In the medical setting, the most important groups are the alpha-hemolytic streptococci, S. pneumoniae and Streptococcus Viridans-group, and the beta-hemolytic streptococci of Lancefield groups A and B (also known as “Group A strep” and “Group B strep”). Beta-hemolytic streptococci are further characterised via the Lancefield serotyping – based on specific carbohydrates in the bacterial cell wall.[5] These are named Lancefield groups A to V (except I and J).

Alpha-hemolytic

Pneumococci

Inflammation is thought to be the major cause of how pneumococcus causes disease, hence the inflammatory nature of the diagnoses associated with it [ above ].

The Viridans group: alpha-hemolytic

Beta-hemolytic

Alpha-hemolytic S. viridans (right) and beta-hemolytic S. pyogenes (left) streptococci growing on blood agar

[edit] Group A

S. pyogenes, also known as Group A Streptococcus (GAS), is the causative agent in Group A streptococcal infections, including streptococcal pharyngitis ("strep throat"), acute rheumatic fever, scarlet fever, acute glomerulonephritis and necrotizing fasciitis. Strep. pyogenes is the other major cause of streptococcal infection in humans, after pneumococcus. However, rather than being directly invasive and inflammatory, it seems to cause local infection, but then its other actions are via toxins: whether affecting kidneys in post strep glomerulonephritis, heart valves in rheumatic fever, the scarlet skin of scarlet fever or dissolving tissue in necrotizing fasciitis. Other Streptococcus species may also possess the Group A antigen, but human infections by non-S. pyogenes GAS strains (some S. dysgalactiae subsp. equisimilis and S. anginosus Group strains) appear to be uncommon.
Group A Streptococcus infection is generally diagnosed with a Rapid Strep Test or by culture. Rheumatic fever, a disease that affects the joints, kidneys and heart valves, is a consequence of untreated strep A infection caused not by the bacterium itself. Rheumatic fever is caused by the antibodies created by the immune system to fight off the infection cross-reacting with other proteins in the body. This cross-reaction causes the body to essentially attack itself and leads to the damage above.

Group B

S. agalactiae, or GBS, causes pneumonia and meningitis in neonates and the elderly, with occasional systemic bacteremia. They can also colonize the intestines and the female reproductive tract, increasing the risk for premature rupture of membranes and transmission to the infant. The American College of Obstetricians and Gynecologists, American Academy of Pediatrics and the Centers for Disease Control recommend that all pregnant women between 35 and 37 weeks gestation should be tested for GBS. Women who test positive should be given prophylactic antibiotics during labor, which will usually prevent transmission to the infant.[6] In the UK, clinicians have been slow to implement the same standards as the US, Australia and Canada. In the UK, only 1% of maternity units test for the presence of Group B Streptococcus.[7] Although the Royal College of Obstetricians and Gynaecologists issued risk-based guidelines in 2003 (due for review 2006), the implementation of these guidelines has been patchy. As a result, over 75 infants in the UK die each year of GBS-related disease, and another 600 or so suffer serious infection, most of which could be prevented;[8] however, this is yet to be substantiated by randomized, controlled trial in the UK setting and, given the evidence for the efficacy of testing and treating from other countries, it may be that the large-scale trial necessary would receive neither funding nor ethics approval.[9]

Group C

This group includes S. equi, which causes strangles in horses,[10] and S. zooepidemicus - S. equi is a clonal descendent or biovar of the ancestral S. zooepidemicus - which causes infections in several species of mammals, including cattle and horses. Streptococcus dysgalactiae is also a member of Group C, β-haemolytic streptococci that can cause pharyngitis and other pyogenic infections similar to Group A streptococci.

Group D (enterococci)

Many former Group D streptococci have been reclassified and placed in the genus Enterococcus (including Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Enterococcus avium).[11] For example, Streptococcus faecalis is now Enterococcus faecalis.
The remaining nonenterococcal Group D strains include Streptococcus bovis and Streptococcus equinus.
Nonhemolytic streptococci rarely cause illness. However, weakly hemolytic group D beta-hemolytic streptococci and Listeria monocytogenes (which is actually a Gram-positive bacillus) should not be confused with nonhemolytic streptococci.

Group F streptococci

Group F streptococci were first described in 1934 by Long and Bliss amongst the "minute haemolytic streptococci".[12] They are also known as Streptococcus anginosus (according to the Lancefield classification system) or as members of the S. milleri group (according to the European system).

Group G streptococci

These streptococci are usually, but not exclusively, beta-hemolytic. Streptococcus canis is an example of a GGS which is typically found on animals, but can cause infection in humans.


2 comments:

  1. My little princess is so beautiful) I underwent using Dr Itua Herbal Medicine. I had a miscarriage 7 years ago. I still can’t hold back my tears when I remember that horrible period of my life. After my loss I couldn’t get back to life for a long time. I’m glad I have my husband. He gave me support I needed the most. Together we can do everything! We wanted to have kids for a really long time. We’ve gone through a lot, but if you want something badly, you’ll get it! I had to search online on how i can use herbal remedy due to my infertility then i came across Dr Itua how he cure all kind diseases and helped a lady from Kansas City to get pregnant so i contacted him on email,He gave me some guild lines to follow he also send me his herbal medicine via courier service which he instruct me on how to drink it for two weeks really i did and after 7 days of having intercourse with my husband few days later i noticed my period didn't come then i decided to go for check up i was pregnant with a baby,Dr Itua is a genuine miracle man..I've got pregnant from first attempt. We were over the moon! Our girls were born in May 2015. We've just celebrated their first birthday. Finally joy and peace came to our family.Here his Email/Whatsapp Number...+2348149277967/  drituaherbalcenter@gmail.com He cure the following...infertility Liver/kidney Inflammatory,Diabetis,Herpes Virus, Lupus, HPV, Cancer, Hiv/Aids, Hepatitis, Als, MS, Menstrual Cramp,  Fribroid.

    ReplyDelete
  2. I want to share with you all on how Dr Itua saves my life with his powerful Herbal medicines, I was diagnosed of Oral/Ovarian Cancer which i suffered from for 5 years with no positive treatment until when My son came to me in the hospital when i was laying down on my dying bed waiting for god to call out my name to join him in heaven.
    My son was so excited that very day he came across Dr Itua on Blogspot, we decided to give him a try although we Americans are so scared to trust Africans but i really have no choice that time to choose life in between so we gave a try to Dr Itua Herbal medicines, god willing he was a good man with a god gift. Dr Itua sent us herbal medicine. It was three bottles. I took it for three weeks as an instructor and these herbal medicines heal me, cure my Oral/Ovarian Cancer completely. I have been living for 9 months now with a healthy life with no more symptoms.
    I'm sponsoring Dr Itua in LA Advert on Cancer patent seminar which my son will be participating too and other patent Dr Itua has cured from all kind of human disease, also if you are sick from disease like,Epilepsy,Breast Cancer,Prostate Cancer,Throat cancer,Thyroid Cancer,Uterine cancer,Fibroid,Angiopathy, Ataxia,Arthritis,Brain cancer,Hiv,. Vaginal cancer,Herpes,Colon-Rectal Cancer,Chronic Disease.Amyotrophic Lateral Sclerosis,Brain Tumor,Fibromyalgia,Fluoroquinolone Toxicity,Multiple myeloma,Tach Diseases,Leukemia,Liver cancer,
    Esophageal cancer,Gallbladder cancer,,Bladder cancer,Gestational trophoblastic disease,Head and neck cancer,Hodgkin lymphoma
    Intestinal cancer,Kidney cancer,Hpv,Lung cancer,Adrenal cancer.Bile duct cancer,Bone cancer,Melanoma,Mesothelioma,Neuroendocrine tumors
    Non-Hodgkin lymphoma,Cervical Cancer,Oral cancer,Hepatitis,Skin cancer,Soft tissue sarcoma,Spinal cancer,Pancreatic Cancer, Stomach cancer
    Testicular cancer,
    Syndrome Fibrodysplasia Ossificans ProgresS sclerosis,Alzheimer's disease,Chronic Diarrhea,Copd,Parkinson,Als,Adrenocortical carcinoma Infectious mononucleosis,Vulvar cancer,Ovarian cancer,,Sinus cancer, Here Is The Wonderful Healer Contact. Name_ Doctor Itua, Email Contact: drituaherbalcenter@gmail.com, Phone/WhatsApp: +2348149277967

    ReplyDelete