Antimicrobial susceptibility patterns of respiratory Gram-negative bacterial isolates from COVID-19 patients in Switzerland

Abstract

Background Bacterial superinfections associated with COVID-19 are common in ventilated ICU patients and impact morbidity and lethality. However, the contribution of antimicrobial resistance to the manifestation of bacterial infections in these patients has yet to be elucidated. Methods We collected 70 Gram-negative bacterial strains, isolated from the lower respiratory tract of ventilated COVID-19 patients in Zurich, Switzerland between March and May 2020. Species identification was performed using MALDI-TOF; antibiotic susceptibility profiles were determined by EUCAST disk diffusion and CLSI broth microdilution assays. Selected Pseudomonas aeruginosa isolates were analyzed by whole-genome sequencing. Results P. aeruginosa (46%) and Enterobacterales (36%) comprised the two largest etiologic groups. Drug resistance in P. aeruginosa isolates was high for piperacillin/tazobactam (65.6%), cefepime (56.3%), ceftazidime (46.9%) and meropenem (50.0%). Enterobacterales isolates showed slightly lower levels of resistance to piperacillin/tazobactam (32%), ceftriaxone (32%), and ceftazidime (36%). All P. aeruginosa isolates and 92% of Enterobacterales isolates were susceptible to aminoglycosides, with apramycin found to provide best-in-class coverage. Genotypic analysis of consecutive P. aeruginosa isolates in one patient revealed a frameshift mutation in the transcriptional regulator nalC that coincided with a phenotypic shift in susceptibility to β-lactams and quinolones. Conclusions Considerable levels of antimicrobial resistance may have contributed to the manifestation of bacterial superinfections in ventilated COVID-19 patients, and may in some cases mandate consecutive adaptation of antibiotic therapy. High susceptibility to amikacin and apramycin suggests that aminoglycosides may remain an effective second-line treatment of ventilator-associated bacterial pneumonia, provided efficacious drug exposure in lungs can be achieved.

Aetiology and antibiotic susceptibility pattern of bacterial pathogens in respiratory specimens of COVID-19 patients on respiratory support: A tertiary care hospital study.

“…Unlikely, a study conducted in Switzerland 15 isolated Pseudomonas aeruginosa (46%) as most common isolate. 15 Similarly, a study from Germany and Iran revealed the Klebsiella spp (47.82% & 25.59%) were the most common isolated gram negative bacteria from the samples of COVID-19 patient which is also in accordance to our study. 19,20 This discrepancy may be due to the fact that difference in geographical location might be a factor of different bacterial pathogen isolation.…”

“…21 Majority of the gram negative isolates were resistant to ampicillin, amoxicillin + clavulanic acid, ceftriaxone, piperacillin + tazobactam and the same has been documented by the studies done Gysin et al,. 15 They reported that piperacillin/tazobactam (65.6%), cefepime (56.3%), ceftazidime (46.9%) and meropenem (50.0%) were resistant drugs against gram negative isolated from COVID-19 patients. In our study, aminoglycoside and colistin was the most sensitive drugs against the isolated gram negative isolates which is in accordance with the study conducted by Gysin et al 15 , Sharifipour et al, 18 and Mahmoudi et al, 20 Moreover, studies conducted by Mahmoudi et al, 20 and Sharifipour et al, 18 reported that vancomycin is most effective antibiotic against MSSA and MRSA which is accordance to our study.…”

“…But still, the role of antibiotics and its resistance is yet to be elucidated in such patients for progression of disease. 15 Therefore, the present study was aimed to find out etiology and antibiotic susceptibility pattern of bacterial pathogens in respiratory specimens of covid-19 patients on respiratory support in tertiary care hospital of Lahore during January-December 2021. We also checked the burden of bla IMP and bla VIM genes as these genes are responsible for carbapenem resistant in bacterial isolates.…”

The rise in antimicrobial resistance: An obscure issue in COVID-19 treatment

“…We found that E. coli, K. Pneumoniae, and Pseudomonas spp. were the most commonly isolated bacteria, while Marina G et al [17] reported that Pseudomonas aeruginosa and Enterobacterales were the most prevalent in their study. The isolation of organisms is being influenced by the geographical region.…”

The Complexity of Co-Infections in the Era of COVID-19

“…Cusumano et al [163] particularly find that Staphylococcus aureus bacteremia may be an important predictor of worse outcome. There is an increasing antibiotic resistance profile with co-infection [122,123,127,135,137,140,142,144,146,157,159,160,163,164]. For example, some American centers have been particularly inundated with multi-resistant coliforms [135,157].…”