Molecular epidemiology of carbapenem-resistant Enterobacteriaceae isolated from patients in COVID-19 wards and ICUs in a Bulgarian University Hospital.

Many studies report an increase in antimicrobial resistance of Gram - negative bacteria during the COVID-19 pandemic. Our aim was to evaluate the epidemiological relationship between carbapenem-resistant (CR) Enterobacteriaceae isolates from patients in COVID-19 wards and to investigate the main mechanisms of carbapenem resistance in these isolates during the period April 2020-July 2021. A total of 45 isolates were studied: Klebsiella pneumoniae (n = 37), Klebsiella oxytoca (n = 2), Enterobacter cloacae complex (n = 4) and Escherichia coli (n = 2). Multiplex PCR was used for detection of genes encoding carbapenemases from different classes (blaKPC, blaIMP, blaVIM, blaNDM, blaOXA-48). For epidemiological typing and analysis, ERIC PCR was performed. Two clinical isolates of E. cloacae, previously identified as representatives of two dominant hospital clones from the period 2014-2017, were included in the study for comparison. In the CR K. pneumoniae group, 23 (62.2%) carried blaKPC, 13 (35.1%) blaNDM, 10 (27.0%) blaVIM, and 9 (24.3%) were positive for both blaKPC and blaVIM. The blaKPC was identified also in the two isolates of K. oxytoca and blaVIM in all E. cloacae complex isolates. The two CR isolates of E. coli possessed blaKPC and blaOXA-48 genes. Epidemiological typing identified 18 ERIC profiles among K. pneumoniae, some presented as clusters of identical and/or closely related isolates. The carbapenem resistance in the studied collection of isolates is mediated mainly by blaKPC. During the COVID-19 pandemic intrahospital dissemination of CR K. pneumoniae, producing carbapenemases of different molecular classes, as well as continuing circulation of dominant hospital clones of multidrug-resistant E. cloacae complex was documented.

Gram-negative ESKAPE bacteria bloodstream infections in patients during the COVID-19 pandemic.

Bloodstream infections due to bacteria are a highly consequential nosocomial occurrences and the organisms responsible for them are usually multidrug-resistant. The aims of this study were to describe the incidence of bacteremia caused by Gram-negative ESKAPE bacilli during the COVID-19 pandemic and characterize the clinical and microbiological findings including antimicrobial resistance. A total of 115 Gram-negative ESKAPE isolates were collected from patients with nosocomial bacteremia (18% of the total bacteremias) in a tertiary care center in Mexico City from February 2020 to January 2021. These isolates were more frequently derived from the Respiratory Diseases Ward (27), followed by the Neurosurgery (12), Intensive Care Unit (11), Internal Medicine (11), and Infectious Diseases Unit (7). The most frequently isolated bacteria were Acinetobacter baumannii (34%), followed by Klebsiella pneumoniae (28%), Pseudomonas aeruginosa (23%) and Enterobacter spp (16%). A. baumannii showed the highest levels of multidrug-resistance (100%), followed by K. pneumoniae (87%), Enterobacter spp (34%) and P. aeruginosa (20%). The bla CTX-M-15 and bla TEM-1 genes were identified in all beta-lactam-resistant K. pneumoniae (27), while bla TEM-1 was found in 84.6% (33/39) of A. baumannii isolates. The carbapenemase gene bla OXA-398 was predominant among carbapenem-resistant A. baumannii (74%, 29/39) and bla OXA-24was detected in four isolates. One P. aeruginosa isolate was bla VIM-2 gene carrier, while two K. pneumoniae and one Enterobacter spp were bla NDM gene carriers. Among colistin-resistant isolates mcr-1 gene was not detected. Clonal diversity was observed in K. pneumoniae, P. aeruginosa and Enterobacter spp. Two outbreaks caused by A. baumannii ST208 and ST369 were detected, both belonging to the clonal complex CC92 and IC2. A. baumannii was associated with a death rate of 72% (28/32), most of them (86%, 24/28) extensively drug-resistant or pandrug-resistant isolates, mainly in patients with COVID-19 (86%, 24/28) in the Respiratory Diseases Ward. A. baumannii isolates had a higher mortality rate (72%), which was higher in patients with COVID-19. There was no statistically significant association between the multidrug-resistant profile in Gram-negative ESKAPE bacilli and COVID-19 disease. The results point to the important role of multidrug-resistant Gram-negative ESKAPE bacteria causing bacteremia in nosocomial settings before and during the COVID-19 epidemic. Additionally, we were unable to identify a local impact of the COVID-19 pandemic on antimicrobial resistance rates, at least in the short term.

Bacterial profiles and their antibiotic resistance background in superinfections caused by multidrug-resistant bacteria among COVID-19 ICU patients from southwest Iran.

This study investigated the bacterial causes of superinfections and their antibiotic resistance pattern in severe coronavirus disease 2019 (COVID-19) patients admitted to the intensive care unit (ICU) of Razi Hospital in Ahvaz, southwest Iran. In this cross-sectional study, endotracheal tube (ETT) secretion samples of 77 intubated COVID-19 patients, confirmed by reverse transcription-quantitative polymerase chain reaction, were investigated by standard microbiology test and analytical profile index kit. Antibiotic susceptibility testing was performed by disc diffusion. The presence of Haemophilus influenzae and Mycoplasma pneumoniae was investigated by the polymerase chain reaction (PCR). Using culture and PCR methods, 56 (72.7%) of the 77 COVID-19 patients (mean age of 55 years, 29 male and 27 female) had superinfections. Using culture, 67 isolates including 29 (43.2%) Gram-positive and 38 (56.7%) Gram-negative bacteria (GNB) were identified from 49 COVID-19 patients. The GNB were more predominant than the Gram-positive pathogens. Klebsiella pneumoniae (28.4%, n = 19/67) was the most common isolate followed by Staphylococcus aureus (22.4%, n = 15/67). Using PCR, 10.4% (8/77) and 11.7% (9/77) of ETT secretion specimens had H. influenzae and M. pneumoniae amplicons, respectively. Gram-positive and Gram-negative isolates showed high resistance rates (>70.0%) to majority of the tested antibiotics including fluoroquinolone, carbapenems, and cephalosporins and 68.7% (46/67) of isolates were multidrug-resistant (MDR). This study showed a high frequency rate of superinfections by MDR bacteria among COVID-19 patients in southwest Iran. The prevention of long-term consequences caused by COVID-19, demands continuous antibiotic surveillance particularly in management of bacterial superinfections.