Microbiologic pattern and clinical outcome of non-ICU-acquired pneumonia: Korean HAP registry analysis

Abstract

Background/Aims: Most studies on hospital-acquired pneumonia (HAP) have been conducted in intensive care unit (ICU) settings. This study aimed to investigate the microbiological and clinical characteristics of non-ICU-acquired pneumonia (NIAP) and to identify the factors affecting clinical outcomes in Korea.Methods: This multicenter retrospective cohort study was conducted in patients admitted to 13 tertiary hospitals between July 1, 2019 and December 31, 2019. Patients diagnosed with NIAP were included in this study. To assess the prognostic factors of NIAP, the study population was classified into treatment success and failure groups.Results: Of 526 patients with HAP, 379 were diagnosed with NIAP. Overall, the identified causative pathogen rate was 34.6% in the study population. Among the isolated organisms (n = 113), gram-negative bacilli were common pathogens (n = 91), such as <i>Pseudomonas aeruginosa</i> (n = 25), <i>Acinetobacter baumannii</i> (n = 23), and <i>Klebsiella pneumoniae</i> (n = 21). The multidrug resistance rates of <i>A. baumannii</i>, <i>P. aeruginosa</i>, and <i>K. pneumoniae</i> were 91.3%, 76.0%, and 57.1%, respectively. Treatment failure was significantly associated with <i>K. pneumoniae</i> (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.35 to 9.05; <i>p</i> = 0.010), respiratory viruses (OR, 3.81; 95% CI, 1.34 to 10.82; <i>p</i> = 0.012), hematological malignancies (OR, 3.54; 95% CI, 1.57 to 8.00; <i>p</i> = 0.002), and adjunctive corticosteroid treatment (OR, 2.40; 95% CI, 1.27 to 4.52; <i>p</i> = 0.007).Conclusions: The causative pathogens of NIAP in Korea are predominantly gram-negative bacilli with a high rate of multidrug resistance. These were not different from the common pathogens of ICU-acquired pneumonia.

The small RNA PrrH aggravates Pseudomonas aeruginosa -induced acute lung injury by regulating the type III secretion system activator ExsA

“…P. aeruginosa is the leading Gram-negative cause of nosocomial pneumonia ( 1 – 6 ). P. aeruginosa relies primarily on the secretion of large amounts of virulence factors to evade host immunity and successfully infect and cause disease ( 15 , 35 ).…”

“…Pseudomonas aeruginosa is a multidrug-resistant opportunistic pathogen that causes acute and chronic infections in immunocompromised individuals with chronic obstructive pulmonary disease, cystic fibrosis, and serious burns. P. aeruginosa is the most common cause of nosocomial pneumonia among Gram-negative bacteria ( 1 – 6 ). And in recent years, P. aeruginosa infections cause high mortality due to its high drug resistance and virulence ( 7 – 9 ), which makes them extremely difficult to treat ( 10 – 14 ).…”

Empiric Anti-Pseudomonal β-Lactam Monotherapy Versus Fluoroquinolone Combination Therapy in Patients With Hospital-Acquired Pneumonia: A Multicenter Cohort Study With Propensity Score Matching

“…In recent years, A. baumannii, with a high MDR rate, has become the most common pathogen in patients with HAP. 5 19 20 Although we excluded patients treated empirically with carbapenem, colistin, or aminoglycosides, the most common pathogen was still A. baumannii, and the MDR rate was as high as 90.3%. The appropriateness of initial empiric antibiotics for A. baumannii was only 32.4%, and there were no significant differences in the appropriateness of initial antibiotics or 30-day mortality between the two groups.…”

Respiratory Viruses in Nosocomial Pneumonia: An Evolving Paradigm

“…Conversely, in a multicenter report dealing with non-ICU patients with NP, Jang and co-workers examined 379 subjects [ 13 ]. While a culprit organism was only identified in approximately one-third of the population, respiratory viruses accounted for 5% of all pathogens identified [ 13 ]. This number, although deriving from a non-ventilated population, is strikingly consistent with the VAP study described earlier.…”

“…In contrast to prior reports, the parainfluenza virus represented the most commonly recovered virus. Moreover, distinct is the multicenter nature of this registry substantially enhances its generalizability and reveals more complex initiatives are possible for evaluating the epidemiology of viral NP [ 13 ].…”