The emergence of multi-drug-resistant bacteria causing healthcare-associated infections in COVID-19 patients: a retrospective multi-centre study.

INTRODUCTION: We evaluated the prevalence, aetiologies and antibiotic resistance patterns of bacterial infections in hospitalized patients with laboratory-confirmed SARS-CoV-2. We also investigated comorbidities, risk factors and the mortality rate in COVID-19 patients with bacterial infections. METHODS: This retrospective observational study evaluated medical records of 7249 randomly selected patients with COVID-19 admitted to three clinical centres between 1st January 2021 and 16th February 2022. A total of 6478 COVID-19 patients met the eligibility criteria for analysis. RESULTS: The mean age of the patients with SARS-CoV-2 and bacterial infections was 68.6 ± 15.5 years (range: 24-94 years). The majority of patients (68.7%) were older than 65 years. The prevalence of bacterial infections among hospitalized COVID-19 patients was 12.9%, most of them being hospital-acquired (11.5%). Bloodstream (37.7%) and respiratory tract infections (25.6%) were the most common bacterial infections. Klebsiella pneumoniae and Acinetobacter baumannii caused 25.2% and 23.6% of all bacterial infections, respectively. Carbapenem-resistance in Enterobacterales, A. baumannii and Pseudomonas aeruginosa were 71.3%, 93.8% and 69.1%, respectively. Age >60 years and infections caused by ≥3 pathogens were significantly more prevalent among deceased patients compared with survivors (P<0.05). Furthermore, 95% of patients who were intubated developed ventilator-associated pneumonia. The overall in-hospital mortality rate of patients with SARS-CoV-2 and bacterial infections was 51.6%, while 91.7% of patients who required invasive mechanical ventilation died. CONCLUSIONS: Our results reveal a striking association between healthcare-associated bacterial infections as an important complication of COVID-19 and fatal outcomes.

Clinical and molecular characteristics of OXA-72-producing Acinetobacter baumannii ST636 outbreak at a neonatal intensive care unit in Serbia.

AIM: To describe an Acinetobacter baumannii outbreak among preterm neonates in a neonatal intensive care unit (NICU) in Serbia. METHODS: A case-control study was conducted in the NICU at the Institute of Neonatology, Belgrade, Serbia. The case definition of A. baumannii bloodstream infection (BSI) was blood culture confirmation of systemic infection. Isolation, identification and susceptibility testing were performed using conventional methods. Molecular characterization of isolates included resistance gene detection, pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing. Outcomes and clinical and demographic data were obtained from patients' medical records. An infection prevention team was formed and infection control interventions were implemented. FINDINGS: During the outbreak period (May-July 2018), there were 13 cases of A. baumannii BSI among 82 hospitalized neonates. All A. baumannii strains were carbapenem resistant and susceptible to colistin. Molecular characterization of the isolates revealed that they harboured blaOXA66 and blaOXA72 beta-lactamases and belonged to sequence type 636, while the PFGE pattern indicated clonal spread. Lower gestational age, lower Apgar score, vaginal delivery and mechanical ventilation were risk factors for A. baumannii infection. Four patients died, eight patients were treated successfully with colistin, and one patient with sepsis and meningitis on dual ampicillin-sulbactam and colistin therapy recovered with sequelae. The outbreak was eventually controlled by reinforcement of the infection control measures based on a multi-tiered interventional approach. CONCLUSION: This is the first description of an outbreak of BSI among preterm neonates caused by A. baumannii blaOXA66/blaOXA72/ST636 in Serbia.

Gelatinases A and B and Antioxidant Enzyme Activity in the Early Phase of Acute Myocardial Infarction.

Oxidative stress plays important roles in the pathophysiology of acute myocardial infarction (AMI). The aim of this study was to investigate the correlation of the oxidative stress status and matrix metalloproteinase activity in AMI patients in comparison to controls. This study included 136 subjects: 68 patients with AMI (42 males/26 females; mean age 58.5 ± 10.5 years) and 68 controls (37 males/29 females; mean age 60.2 ± 12.4 years). Gelatinases A and B were assayed using gelatin zymography, enzyme activities were obtained spectrophotometrically. Gelatinase A and B activities were increased in the AMI patients' group compared to the control. Activities of serum superoxide dismutase (SOD) and xanthine oxidase (XO) were significantly higher in AMI patients (106.53 ± 23.45 U/l, P < 0.001 and 158.18 ± 29.59 U/l, P < 0.001) than in the control group (55.99 ± 10.79 U/l and 79.81 ± 7.93 U/l). The activity of catalase (CAT) in the sera of AMI patients was lower (271.31 ± 7.53 U/l, P < 0.005) than in the control group (305.94 ± 97.28 U/l). Plasma glutathione peroxidase (GPx) and glutathione reductase (GR) in AMI patients were significantly higher (582.47 ± 184.81 U/l, P < 0.001 and 59.64 ± 21.88 U/l, P < 0.001) than in the control group (275.32 ± 104.69 U/l and 47.71 ± 20.05 U/l). The present findings demonstrate activation of gelatinases A and B and oxidative stress markers in the early stage of AMI. Gelatinases, detected at high levels in AMI patients only, indicate their noticeable predisposition for becoming additional biomarkers of the early phase of AMI.

Matrix Metalloproteinase-2 and -9, Lactate, and Malate Dehydrogenase and Lipid Peroxides in Sera of Patients with Colorectal Carcinoma.

Matrix metalloproteinases (MMPs) are involved in tumour invasion and metastasis of colorectal carcinoma. Oxidative stress represents one of the possible mechanisms that activate inactive MMPs. Oxidative stress increases lipid peroxidation, which causes impaired membrane permeability and leakage of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) into circulation. Our aim was to assess the activity of MMP-2 and MMP-9 and its relation to the parameters of oxidative stress and membrane damage markers in patients with different TNM (tumour, lymph nodes, metastasis) stages of colorectal carcinoma. MMP-2 and -9 activities were evaluated by gelatin zymography. Oxidative stress was examined by quantifying serum malondialdehyde (MDA) concentration. LDH and MDH activities were determined spectrophotometrically. The activities of MMP-2 and -9 were significantly higher in the sera of colorectal carcinoma patients when compared to healthy subjects. There was a stage-dependent increase in relative MMP-2 activity compared to the overall serum gelatinolytic activity. The activity of MMP-9 was the highest in TNM III. The MDA concentration and the LDH and MDH activities were significantly higher in colorectal carcinoma patients than in controls, while LDH and MDH activities were stage dependent. There was significant correlation between serum MMP-2 and LDH activity in TNM II, III and IV patients. A stage-dependent increase of LDH and MDH activity was observed. We highlight here that MMP-9 could be a 100% sensitive marker of TNM stage III of colorectal carcinogenesis. In this study it was shown for the first time that gelatinolytic activity in colorectal carcinoma is associated with redox imbalance.