Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

Branka Bedenić; Vesna Bratić; Slobodan Mihaljević; Anita Lukić; Karlo Vidović; Krešimir Reiner; Silvia Schöenthaler; Ivan Barišić; Gernot Zarfel; Andrea Grisold

doi:10.3390/pathogens12010117

Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

Pathogens. 2023 Jan 10;12(1):117. doi: 10.3390/pathogens12010117.

Authors

Affiliations

¹ Department for Microbiology and Parasitology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia.
² Clinical Department for Clinical and Molecular Microbiology, School of Medicine, University Hospital Center Zagreb, University of Zagreb, 10000 Zagreb, Croatia.
³ Clinical Department for Anestesiology, Reanimatology and Intensive Care, University Hospital Centre Zagreb, University of Zagreb, 10000 Zagreb, Croatia.
⁴ Varaždin General Hospital, 42000 Varaždin, Croatia.
⁵ Austrian Institute of Technology, 1210 Vienna, Austria.
⁶ Institute for Hygiene, Microbiology and Environmental Medicine, Medical University Graz, 8010 Graz, Austria.

Abstract

During November to December 2020, a high rate of COVID-19-associated pneumonia with bacterial superinfections due to multidrug-resistant (MDR) pathogens was recorded in a COVID-19 hospital in Zagreb. This study analyzed the causative agents of bacterial superinfections among patients with serious forms of COVID-19. In total, 118 patients were hospitalized in the intensive care unit (ICU) of the COVID-19 hospital. Forty-six out of 118 patients (39%) developed serious bacterial infection (VAP or BSI or both) during their stay in ICU. The total mortality rate was 83/118 (70%). The mortality rate due to bacterial infection or a combination of ARDS with bacterial superinfection was 33% (40/118). Six patients had MDR organisms and 34 had XDR (extensively drug-resistant). The dominant species was Acinetobacter baumannii with all isolates (34) being carbapenem-resistant (CRAB) and positive for carbapenem-hydrolyzing oxacillinases (CHDL). One Escherichia coli causing pneumonia harboured the bla_CTX-M-15 gene. It appears that the dominant resistance determinants of causative agents depend on the local epidemiology in the particular COVID center. Acinetobacter baumannii seems to easily spread in overcrowded ICUs. Croatia belongs to the 15 countries in the world with the highest mortality rate among COVID-19 patients, which could be in part attributable to the high prevalence of bacterial infections in local ICUs.

Keywords: Acinetobacter baumannii; COVID-19; OXA-48; multidrug-resistant bacteria.

Grants and funding

Grant from the University of Zagreb School of Medicine (Carbapenemases in hospitals, nursing homes and environment, grant number: 380-59-10106-16-2983).