Microbiology: Pseudomonas Aeruginosa
Description of the Microorganism
Pseudomonas aeruginosa, a nosocomial pathogen, is the most wide-spread aerobic Gram-negative microbe in the genus Pseudomonas (Moore, Cunningham, & Donaldson, 2016). It is naturally present in the environment. P. aeruginosa is highly adaptable and can survive in water, soil, fuel, disinfectants and other substances and it can easily withstand changes in the environment (Porras-Gómez, Vega-Baudrit & Núñez-Corrales, 2012). Due to its spread, high versatility, virulence and immunity, P. aeruginosa is an extremely dangerous pathogen.
2. Virulence Factors
P. aeruginosa forms a biofilm, which protects it from host antibodies and antibiotics, facilitates its attachment to host epithelia and helps its survival in numerous environments (Moore et al., 2016). Lipopolysaccharide (LPS) O-antigen is an external layer that protects bacterial membranes (Hauser, 2011). The microbe produces substances that help its invasion. It generates lipopolysaccharides and elastase that damage host tissues and “pili, flagella, exoenzyme S, and mucoid exopolysaccharide” are the microbe’s adherence tools (Porras-Gómez et al., 2012). The microbe has the type III secretion (TTS), which creates toxic proteins (ExoU, ExoS, ExoY and ExoT) and injects them into host cells (Hauser, 2011; Moore et al., 2016). The pathogen’s quorum-sensing (QS) controls the density of its population by releasing elastase and pyocyanin (Hauser, 2011). Its virulence factors make P. aeruginosa highly treatment-resistant.
3. Immunity
P. aeruginosa has multidrug resistance (MDR), which is immunity to at least four types of antibiotics, and it has natural immunity to ampicillin, amoxicillin, ceftriaxone, trimethoprim and the like (Porras-Gómez et al., 2012). The microbe’s high mutation rates and membrane efflux pumps, which remove antibiotics out of microbial cells, increase its resistance (Porras-Gómez et al., 2012). Thus, its immunity and biofilm formation facilitate the pathogen’s survival in hostile environments and contribute to its pathogenicity and infecting potential.
4. Infectious Disease Information
P. aeruginosa causes many infections in healthcare settings. P. aeruginosa may cause hospital-acquired or ventilator-acquired pneumonia (VAP), endocarditis, urinary tract infections (UTI), keratitis, necrotizing enterocolitis, and other infections in inpatients (Moore et al., 2016). P. aeruginosa infections develop after using contaminated hospital equipment. VAP results from endotracheal intubation during mechanical ventilation; UTI develops after catheterization or surgery; burns may be contaminated with P. aeruginosa; endocarditis may develop after intravenous injections and so on (Streeter & Katouli, 2016; Moore et al., 2016). P. aeruginosa contributes to morbidity and mortality in healthcare facilities and requires new treatment options.
5. Epidemiology
P. aeruginosa infections are frequent among hospitalized patients. The pathogen causes fifty-one thousand infections in the US healthcare settings every year; over six thousand infections are generated by MDR P. aeruginosa with about four hundred deaths yearly (Centers for Disease Control and Prevention (CDC), 2014). Hospitals are the reservoirs of P. aeruginosa that spreads on hospital employees’ hands and equipment. A patient can get infected during a surgery, in a bathtub and so on (CDC, 2014). Correct surveillance and prevention strategies can reduce P. aeruginosa prevalence.
6. Presentations
VAP symptoms include sepsis, increased oxygen demand, amplified respiratory rate, increased …
