(1) The staphylococci and corynebacteria occur at every site listed. Staphylococcus epidermidis is highly adapted to the diverse environments of its human host. S. aureus is a potential pathogen. It is a leading cause of bacterial disease in humans. It can be transmitted from the nasal membranes of an asymptomatic carrier to a susceptible host.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
S. epidermidis. Scanning EM. CDC. (2) Many of the normal flora are either pathogens or opportunistic pathogens, The asterisks indicate members of the normal flora a that may be considered major pathogens of humans.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]S. aureus. Gram stain.
(3)
Streptococcus mutans is the primary bacterium involved in plaque formation and initiation of dental caries. Viewed as an opportunistic infection, dental disease is one of the most prevalent and costly infectious diseases in the United States.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Streptococcus mutans. Gram stain. CDC
(4)
Enterococcus faecalis was formerly classified as
Streptococcus faecalis. The bacterium is such a regular a component of the intestinal flora, that many European countries use it as the standard indicator of fecal pollution, in the same way we use
E. coli in the U.S. In recent years,
Enterococcus faecalis has emerged as a significant, antibiotic-resistant, nosocomial pathogen.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Vancomycin Resistant
Enterococcus faecalis. Scanning E.M. CDC
(5)
Streptococcus pneumoniae is present in the upper respiratory tract of about half the population. If it invades the lower respiratory tract it can cause pneumonia.
Streptococcus pneumoniae causes 95 percent of all bacterial pneumonia.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Streptococcus pneumoniae. Direct fluorescent antibody stain. CDC.
(6)
Streptococcus pyogenes refers to the Group A, Beta-hemolytic streptococci. Streptococci cause tonsillitis (strep throat), pneumonia, endocarditis. Some streptococcal diseases can lead to rheumatic fever or nephritis which can damage the heart and kidney.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Streptococcus pyogenes. Gram stain.
(7)
Neisseria and other Gram-negative cocci are frequent inhabitants of the upper respiratory tract, mainly the pharynx.
Neisseria meningitidis, an important cause of bacterial meningitis, can colonize as well, until the host can develop active immunity against the pathogen.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Neisseria meningitidis. Gram stain.
(8) While
E. coli is a consistent resident of the small intestine, many other enteric bacteria may reside here as well, including
Klebsiella, Enterobacter and
Citrobacter. Some strains of
E. coli are pathogens that cause intestinal infections, urinary tract infections and neonatal meningitis.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]E. coli. Scanning E.M. Shirley Owens. Center for Electron Optics. Michigan State University.
(9)
Pseudomonas aeruginosa is the quintessential opportunistic pathogen of humans that can invade virtually any tissue. It is a leading cause of hospital-acquired (nosocomial) Gram-negative infections, but its source is often exogenous (from outside the host).
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Colonies of
Pseudomonas aeruginosa growing on an agar plate. The most virulent Pseudomonas species produce mucoid colonies and green pigments such as this isolate.
(10)
Haemophilus influenzae is a frequent secondary invader to viral influenza, and was named accordingly. The bacterium was the leading cause of meningitis in infants and children until the recent development of the Hflu type B vaccine.
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]Haemophilus influenzae. Gram stain.
موضوع: The Normal Flora 
الثلاثاء يناير 05, 2010 10:01 pm