There are many. There are viral pathogens, bacterial pathogens (such as Streptococcus pneumoniae and dozens of others), mycobacteria (tuberculosis), and fungal pathogens, for example
Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, or parasites.
Pneumocystis jirovecii causes pneumonia in people with AIDS. This pathogen was formerly known as Pneumocystic carinii.
Double pneumonia does not identify which kind of pneumonia you have or which pathogen is the cause -- it is only identifying that you have it bilaterally, or in both lungs. Staph pneumonia identifies the actually pathogen causing the infection, Staphlococcus aureus, which is a very virulent pathogen. Staph pneumonia can be deadly if not treated properly. It may be helpful if you understand that there are many different forms of pneumonia, and that being diagnosed with "pneumonia" itself isn't a death sentence by any means -- it simply means you have inflammation and fluid in the lungs. This inflammation and fluid can be caused by a virus, bacteria, fungus or parasite, and sometimes is just caused by damage to lung tissue without any infectious origin at all. In most cases, pneumonia will clear up with antibiotic therapy, and the people with the highest risk of dying from the disease are very young children, elderly, and people with compromised immune systems.
I assume you mean bacterial pneumonia, from there it is dependent on what type of bacteria is causing the pneumonia. For example Streptococcus pneumoniae is gram positive, but Klebsiella pneumoniae gram negative.On the whole though, bacterial pneumonia is more typically caused by gram positive bacteria.
The dimention
pathogen means microorganism, so pathogen diseases means diseases caused by microorganisms
An avirulent pathogen is a pathogen that is unable to cause disease in its host. This may be due to mutations that have reduced its ability to infect or harm the host, making it less pathogenic compared to a virulent pathogen.
You have to specify the pathogen.
This is entirely dependent on the cause of a person's pneumonia. If they have pneumonia caused by a virus or an infectious bacteria (such as the bacteria responsible for pneumonic plague), then those pathogens can be transmitted via respiratory droplets produced by the diseased person. If their pneumonia is not caused by an infectious pathogen (e.g., aspiration pneumonia), then you cannot catch it from them.
There are infinitely many things that do not contribute to the virulence of a pathogen. Elvis does not contribute to the virulence of a pathogen.
Parasites is the pathogen, that is caused marlia
"Pathogen" in Spanish is "patógeno".