Dental plaque might also be a reservoir for bacteria in HCAP. Bacteria have been the most commonly isolated pathogens, although viral and fungal pathogens are potentially found in immunocompromised hosts (patients on chronic immunosuppressed medications, solid organ and bone marrow transplant recipients). In general, the distribution of microbial pathogens varies among institutions, partly because of differences in patient population and local patterns of anti microbial resistance in hospitals and critical care units Common bacterial pathogens include aerobic GNB, such as Pseudomonas aeruginosa, Acinetobacter baumanii, Klebsiella pneumoniae, Escherichia coli as well as gram-positive organisms such as Staphylococcus aureus. In patients with an early onset pneumonia (within 5 days of hospitalization), they are usually due to anti microbial-sensitive bacteria such as Enterobacter spp, E. coli, Klebsiella spp, Proteus spp, Serratia mare scans, community pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, and methicillin-sensitive S. aureus should also be considered. Pneumonia that starts in the hospital tends to be more serious than other lung infections because: people in the hospital are often very sick and cannot fight off germs. The types of germs present in a hospital are often more dangerous and more resistant to treatment than those outside in the community. Pneumonia occurs more often in people who are using a respirator. This machine helps them breathe. Hospital-acquired pneumonia can also be spread by health care workers, who can pass germs from their hands or clothes from one person to another. This is why hand-washing, wearing gloves, and using other safety measures is so important in the hospital.
Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays) and certain oral medications (e.g., sympathomimetic amines and various 2-imidazolines) that constrict blood vessels in the lining of the nose, although evidence has been contradictory. Presentation
The characteristic presentation of RM involves nasal congestion without rhinorrhea, postnasal drip, or sneezing following several days of decongestant use. This condition typically occurs after 5–7 days of use of topical decongestants. Patients often try increasing both the dose and the frequency of nasal sprays upon the onset of RM, worsening the condition. The swelling of the nasal passages caused by rebound congestion may eventually result in permanent turbinate hypertrophy, which may block nasal breathing until surgically removed. Causes
Common issues that lead to overuse of topical decongestants:
Deviated septum
Upper respiratory tract infection
Vasomotor rhinitis
Cocaine use and other stimulant abuse
Pregnancy (these products are not considered safe for pregnancy)
Chronic rhinosinusitis
Hypertrophy of the inferior turbinates

Pathophysiology
The pathophysiology of RM is unclear, although several mechanisms involving norepinephrine signaling have been proposed.