The impact of bacterial pneumonia on patients with COVID-19 infection remains unclear. This prospective observational monocentric cohort study aims to determine the incidence of bacterial community- and hospital-acquired pneumonia (CAP and HAP) and its effect on mortality in critically ill COVID-19 patients admitted to the intensive care unit (ICU) at University Hospital Olomouc between 1 November 2020 and 31 December 2022. The secondary objectives of this study include identifying the bacterial etiology of CAP and HAP and exploring the capabilities of diagnostic tools, with a focus on inflammatory biomarkers. Data were collected from the electronic information hospital system, encompassing biomarkers, microbiological findings, and daily visit records, and subsequently evaluated by ICU physicians and clinical microbiologists. Out of 171 patients suffering from critical COVID-19, 46 (27%) had CAP, while 78 (46%) developed HAP. Critically ill COVID-19 patients who experienced bacterial CAP and HAP exhibited higher mortality compared to COVID-19 patients without any bacterial infection, with rates of 38% and 56% versus 11%, respectively. In CAP, the most frequent causative agents were chlamydophila and mycoplasma; Enterobacterales, which were multidrug-resistant in 71% of cases; Gram-negative non-fermenting rods; and Staphylococcus aureus. Notably, no strains of Streptococcus pneumoniae were detected, and only a single strain each of Haemophilus influenzae and Moraxella catarrhalis was isolated. The most frequent etiologic agents causing HAP were Enterobacterales and Gram-negative non-fermenting rods. Based on the presented results, commonly used biochemical markers demonstrated poor predictive and diagnostic accuracy. To confirm the diagnosis of bacterial CAP in our patient cohort, it was necessary to assess the initial values of inflammatory markers (particularly procalcitonin), consider clinical signs indicative of bacterial infection, and/or rely on positive microbiological findings. For HAP diagnostics, it was appropriate to conduct regular detailed clinical examinations (with a focus on evaluating respiratory functions) and closely monitor the dynamics of inflammatory markers (preferably Interleukin-6).

• Keywords
• adult respiratory distress syndrome (ARDS), bacterial co- or superinfection, bacterial pneumonia, community-acquired pneumonia (CAP), critical coronavirus disease 19 (COVID-19), etiological agents, hospital-acquired pneumonia (HAP), intensive care unit (ICU), mortality, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2),
• Publication type
• Journal Article MeSH

BACKGROUND: Diffuse peritonitis is an acute abdominal condition characterized by high mortality. The main treatment modality is surgery, requiring a subsequent prolonged hospital stay. These patients are, among other things, at risk of developing hospital-acquired pneumonia (HAP), which considerably worsens their treatment outcomes. This study aimed to extend the existing knowledge by providing more detailed microbiological characteristics of complicating HAP in patients with secondary peritonitis, including the identification of isolated bacterial pathogens and their potential sources. METHODS: The 2015-2019 retrospective study comprised all patients with an intraoperatively confirmed diagnosis of secondary diffuse peritonitis who were classified in accordance with the quick Sepsis Related Organ Failure Assessment scoring system. RESULTS: HAP developed in 15% of patients. The 90-day mortality rates were 53% and 24% in patients with and without HAP; respectively. The most frequent pathogens responsible for HAP were Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae complex and Enterococcus faecalis. Multidrug resistance to antibiotics was found in 38% of bacterial pathogens. Clonal spread of these bacterial pathogens among patients was not detected. Rather, the endogenous characteristic of HAP was confirmed. CONCLUSIONS: The initial antibiotic therapy of complicating HAP in patients with secondary peritonitis must be effective mainly against enterobacteria, including strains with the production of ESBL and AmpC beta-lactamases, Pseudomonas aeruginosa and Enterococcus faecalis. The study further highlighted the importance of monitoring the respiratory tract bacterial microflora in patients with secondary peritonitis. The results should be used for initial antibiotic treatment of complicating HAP instances.

• Keywords
• bacteria, etiology, peritonitis, pneumonia,
• Publication type
• Journal Article MeSH

Recent years have witnessed an increased prevalence of intrinsic and acquired beta-lactamase-producing bacteria, severely limiting human and veterinary medicine therapeutic options. The present study aimed to design specific oligonucleotides for rapid PCR detection of the cephalosporinase-encoding gene blaEC (BlaEC family class C beta-lactamase). A total of three primers were designed to detect 2281 variants of the blaEC gene and two sets of primer pairs were also tested against DNA from 11 strains. The study indicates that the proposed primers should be able to detect 100% of all described blaEC genes in different bacterial strains and monitor their spread. After comparing the amino acid sequences, a phylogenetic tree was created based on the presence of conserved amino acids and homologous motifs. More than 24 760 mutations in BlaEC enzymes have been identified. The mutations involving 371 amino acid positions and these hotspots can change the structure and activity of the monitored enzymes. We predicted several BlaEC enzymes with a broadened substrate activity against higher-generation cephalosporins.

• Keywords
• AmpC beta-lactamase, PCR, antibiotic resistance, mutation, primer,
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• Journal Article MeSH

Increasing antimicrobial resistance in nosocomial pathogens, such as Acinetobacter baumannii, is becoming a serious threat to public health. It is necessary to detect β-lactamase-producing microorganisms in clinical settings to be able to control the spread of carbapenem resistance. This study was conducted to evaluate the presence of β-lactamases in a selected clinical isolate of A. baumannii of ST2P/ST195Ox and to characterize possible enzymes, as well as its β-lactam resistome, using PCR and whole-genome sequencing analysis. PCR and sequencing confirmed that the isolate harbored five bla gene alleles, namely, blaADC-73, blaTEM-1, blaOXA-23, blaOXA-58 and blaOXA-66, as well as aminoglycosides, macrolides, sulfonamides and tetracyclines resistance determinants, which were either chromosomally and/or plasmid located. Furthermore, a gene order comparison using MAUVE alignment showed multiple changes compared with the clinical isolate of Malaysian A. baumannii AC30 genome and 76 regions with high homology. This study suggests that resistance to β-lactams in this A. baumannii isolate is mainly due to an overproduction of β-lactamases in combination with other resistance mechanism (efflux pump system).

• Keywords
• Acinetobacter baumannii, PCR, antibiotic resistance, bacteria, β-lactamase,
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• Journal Article MeSH
• Case Reports MeSH

The growing bacterial resistance to available β-lactam antibiotics is a very serious public health problem, especially due to the production of a wide range of β-lactamases. At present, clinically important bacteria are increasingly acquiring new elements of resistance to carbapenems and polymyxins, including extended-spectrum β-lactamases (ESBLs), carbapenemases and phosphoethanolamine transferases of the MCR type. These bacterial enzymes limit therapeutic options in human and veterinary medicine. It must be emphasized that there is a real risk of losing the ability to treat serious and life-threatening infections. The present study aimed to design specific oligonucleotides for rapid PCR detection of ESBL-encoding genes and in silico analysis of selected ESBL enzymes. A total of 58 primers were designed to detect 49 types of different ESBL genes. After comparing the amino acid sequences of ESBLs (CTX-M, SHV and TEM), phylogenetic trees were created based on the presence of conserved amino acids and homologous motifs. This study indicates that the proposed primers should be able to specifically detect more than 99.8% of all described ESBL enzymes. The results suggest that the in silico tested primers could be used for PCR to detect the presence of ESBL genes in various bacteria, as well as to monitor their spread.

• Keywords
• ESBL, PCR, antibiotic resistance, bacteria, primer,
• Publication type
• Journal Article MeSH