Investigation of antimicrobial resistance patterns and molecular typing of Pseudomonas aeruginosa isolates among Coronavirus disease-19 patients.

BACKGROUND: Pseudomonas aeruginosa is a common co-infecting pathogen recognized among COVID-19 patients. We aimed to investigate the antimicrobial resistance patterns and molecular typing of Pseudomonas aeruginosa isolates among Coronavirus disease-19 patients. METHODS: Between December 2020 and July 2021, 15 Pseudomonas aeruginosa were isolated from COVID-19 patients in the intensive care unit at Sina Hospital in Hamadan, west of Iran. The antimicrobial resistance of the isolates was determined by disk diffusion and broth microdilution methods. The double-disk synergy method, Modified Hodge test, and polymerase chain reaction were utilized to detect Pseudomonas aeruginosa extended spectrum beta-lactamase and carbapenemase producers. Microtiter plate assay was performed to evaluate the biofilm formation ability of the isolates. The isolates phylogenetic relatedness was revealed using the multilocus variable-number tandem-repeat analysis method. RESULTS: The results showed Pseudomonas aeruginosa isolates had the most elevated resistance to imipenem (93.3%), trimethoprim-sulfamethoxazole (93.3%), ceftriaxone (80%), ceftazidime (80%), gentamicin (60%), levofloxacin (60%), ciprofloxacin (60%), and cefepime (60%). In the broth microdilution method, 100%, 100%, 20%, and 13.3% of isolates showed resistance to imipenem, meropenem, polymyxin B, and colistin, respectively. Ten (66.6%) isolates were identified as multiple drug resistance. Carbapenemase enzymes and extended spectrum beta-lactamases were identified in 66.6% and 20% of the isolates, respectively and the biofilm formation was detected in 100% of the isolates. The blaOXA-48, blaTEM, blaIMP, blaSPM, blaPER, blaVEB, blaNDM, blaSHV, and blaCTX-M genes were detected in 100%, 86.6%, 86.6%, 40%, 20%, 20%, 13.3%, 6.6%, and 6.6% of the isolates, respectively. The blaVIM, blaGIM, blaGES, and blaMCR-1 genes were not identified in any of the isolates. The MLVA typing technique showed 11 types and seven main clusters and most isolates belong to cluster I, V and VII. CONCLUSION: Due to the high rate of antimicrobial resistance, as well as the genetic diversity of Pseudomonas aeruginosa isolates from COVID-19 patients, it is indispensable to monitor the antimicrobial resistance pattern and epidemiology of the isolates on a regular basis.

Comparison of the efficacy of equivalent doses of dexamethasone, methylprednisolone, and hydrocortisone for treatment of COVID-19-related acute respiratory distress syndrome: a prospective three-arm randomized clinical trial.

BACKGROUND: This prospective controlled clinical trial aimed to compare the efficacy of methylprednisolone, dexamethasone, and hydrocortisone at equivalent doses in patients with severe COVID-19. METHODS: In total, 106 patients with mild to moderate COVID-19-related acute respiratory distress syndrome (ARDS) were randomized to receive either dexamethasone (6 mg once a day), methylprednisolone (16 mg twice a day), or hydrocortisone (50 mg thrice a day) for up to 10 days. All participants received a standard of care for COVID-19. The primary and secondary efficacy outcomes included all-cause 28-day mortality, clinical status on day 28 assessed using the World Health Organization (WHO) eight-category ordinal clinical scale, number of patients requiring mechanical ventilation and intensive care unit (ICU) care, number of ventilator-free days, length of hospital and ICU stay, change in PaO2:FiO2 ratios during the first 5 days after treatment, and incidence of serious adverse events. P-values below 0.008 based on Bonferroni's multiple-testing correction method were considered statistically significant. RESULTS: According to the obtained results, there was a trend toward more favorable clinical outcomes in terms of needing mechanical ventilation and ICU care, number of ventilator-free days, change in PaO2:FiO2 ratios during the first 5 days after treatment, clinical status score at day 28, length of ICU and hospital stay, and overall 28-day mortality in patients receiving dexamethasone compared to those receiving methylprednisolone or hydrocortisone; however, likely due to the study's small sample size, the difference between groups reached a significant level only in the case of clinical status score on day 28 (p-value = 0.003). There was no significant difference in the incidence of serious adverse events between the study groups. CONCLUSION: Based on the results, severe cases of COVID-19 treated with dexamethasone might have a better clinical status at 28-day follow-up compared to methylprednisolone and hydrocortisone at an equivalent dose. Larger multicenter trials are required to confirm our findings.