Bacteriuria in Paediatric Oncology Patients: Clinical Features, Distribution and Antimicrobial Susceptibility of Bacterial Pathogens at University Hospital Centre Zagreb, Croatia over a 4-Year Period.

Bacteriuria in paediatric oncology patients have not been well studied. This retrospective study analysed clinical features, distribution and antimicrobial susceptibility of bacterial pathogens cultured from urine in paediatric oncology patients over a 4-year period (2019-2022). A total of 143 episodes of bacteriuria were documented in 74 patients. Neutropenia was present in 17.5% (25/143), symptoms in 25.9% (37/143) and urinary catheter in 7.0% (10/143) episodes. Symptomatic bacteriuria episodes were statistically significantly more frequent in patients with neutropenia (p = 0.0232). The most common bacterial pathogens were Escherichia coli (n = 49; 32.2%), Klebsiella spp. (n = 34; 22.4%), Pseudomonas aeruginosa (n = 22; 14.5%) and Enterococcus spp. (n = 21; 13.8%). Extended-spectrum ß-lactamases-producing (ESBL) Enterobacterales were found in 11 episodes (11/143; 7.7%) with the highest proportion among Klebsiella pneumoniae isolates (n = 7/34; 20.6%). No carbapenem-resistant Enterobacterales, multidrug-resistant P. aeruginosa or vancomycin-resistant Enterococcus spp. were found. The most important novelties are demonstrating P. aeruginosa as one of the prominent bacteriuria pathogens in this patient population, presence of ESBL isolates and carbapenem-resistant P. aeruginosa later during hospitalization highlights the need for appropriate antimicrobial treatment. However, because of the small number of symptomatic patients, further studies are needed to clarify the importance of including urine culture in the diagnostic process in patients with febrile neutropenia.

Bloodstream Infections in Pediatric Oncology Patients: Bacterial Pathogen Distribution and Antimicrobial Susceptibility at the University Hospital Centre Zagreb, Croatia-A 5-Year Analysis.

The epidemiology of bacterial pathogens causing bloodstream infections (BSIs) in pediatric hematology/oncology patients is changing and resistance to antimicrobial agents is globally spread. We retrospectively assessed demographic, clinical, and microbiologic data of BSIs during a 5-year period at a pediatric hematology/oncology unit from January 1, 2017, to December 31, 2021, at the University Hospital Centre Zagreb, Zagreb, Croatia. In 66 pediatric patients with malignancies, 93 BSI episodes were registered and 97 bacterial isolates were cultured. The Gram-positive versus Gram-negative ratio was 67 (69.1%) versus 30 (30.9%). Coagulase-negative staphylococci (48; 49.6%) were the most frequent isolates, followed by Enterobacterales (17; 17.5%) and Staphylococcus aureus (6; 6.2%). Multidrug resistance isolates included extended spectrum ß-lactamase producers (n=3). Resistance rates to piperacillin/tazobactam, cefepime, and meropenem in Gram-negative isolates were 15.4%, 14.3%, and 0.0%, respectively. Gram-positive bacteria are the most common cause of BSI in our patients. Resistance rates to piperacillin/tazobactam and cefepime in Gram-negative isolates make meropenem a better choice for empirical antimicrobial treatment. As national and hospital data may differ, the surveillance of pathogen distribution and antimicrobial susceptibility in pediatric hematology/oncology wards is necessary to adjust empirical treatment accordingly.

Bloodstream Infections by AmpC-Producing Enterobacterales: Risk Factors and Therapeutic Outcome.

Bloodstream infections associated with AmpC-producing Enterobacterales are severe medical conditions which, without prompt and effective treatment, may have dire ramifications. This study aimed to assess whether certain comorbidities and previous surgical procedures coincide with resistance determinants of AmpC-producing Enterobacterales associated with bloodstream infections. Antibiotic resistance patterns and therapy outcome were also determined. The patients' data obtained revealed that the prevalence of recent surgical procedures, solid organ tumors, metabolic diseases, kidney and liver failure, and hematological malignancies do not differ between resistant and susceptible isolates of AmpC-producing Enterobacterales. Furthermore, no difference was reported in mortality rates. Regarding antibiotic resistance, 34.52% of isolates were confirmed to be resistant (AmpC hyperproduction, ESBL, or carbapenemase). More than one in five AmpC hyperproducers were reported amid Providencia spp., K. aerogenes, E. cloacae, and C. freundii. strains. Carbapenemases were mostly noted in Providencia spp. followed by M. morganii and K. aerogenes strains. Serratia marcescens had the highest proportion of ESBLsof ESBLs. Resistance to expanded-spectrum cephalosporins of Providencia spp. and K. aerogenes strains exceeded 50%, and resistance to meropenem over 10% was observed only in C. freundii strains. Enterobacterales' ever-growing resistance to antibiotics is becoming quite a challenge for clinicians and new treatment options are required.

Increasing trend in enterococcal bacteraemia and vancomycin resistance in a tertiary care hospital in Croatia, 2017-2021.

BACKGROUND: The epidemiology of enterococcal bacteraemia has changed worldwide and vancomycin-resistant enterococci increasingly cause healthcare-associated infections) with limited treatment options. Studies show heterogeneity among countries, regions and individual hospitals. METHODS: We retrospectively analysed enterococcal bacteraemia with Enterococcus faecalis and E. faecium at the largest hospital in Croatia, University Hospital Centre Zagreb from January 2017 to December 2021. RESULTS: A total of 432 cases of enterococcal bacteraemia were identified with 256 (59.3%) due to E. faecalis and 176 (40.7%) to E. faecium. Enterococcal bacteraemia occurred more frequently in men (n = 270; 62.5%) and the median age of all patients was 62 years (IQR: 0-92). We found statistically significant increase in the incidence trend of bacteraemic episodes with an annual percent change of 20.9% (95% confidence interval 14.3 to 27.8; p = .002) predominantly due to an increase of E. faecalis bacteraemia. The majority of patients (362/432; 83.8%) had healthcare-associated infections and 38.0% (165/432) of patients were in the intensive care unit. The proportion of vancomycin-resistant enterococcal bacteraemia increased from 12.7% (n = 8/63) in 2017 to 25.7% (n = 29/113) in 2021, statistically significant increasing trend (p = .0455), mainly due to an increased proportion of vancomycin-resistant E. faecium (p = .0169). CONCLUSIONS: This is the first study describing the trends in enterococcal bacteraemia and vancomycin-resistance in enterococci in Croatia. We found a rising trend in enterococcal bacteraemia and in the proportion of vancomycin resistance and identified the most vulnerable patient groups, notably intensive care unit patients.

Epidemiology of Candidemia: Three-Year Results from a Croatian Tertiary Care Hospital.

Invasive candidosis is the most common invasive fungal infection in hospitalized patients and is associated with a high mortality rate. This is the first study from a Croatian tertiary care hospital describing epidemiology, risk factors and species distribution in patients with candidemia. A three-year retrospective observational study, from 2018 to 2020, was performed at the University Hospital Centre Zagreb, Zagreb, Croatia. A total of 160 patients with candidemia (n = 170 isolates) were enrolled. Candidemia incidence increased from 0.47 to 0.69 per 1000 admissions in 2018 and 2020, respectively. Ninety-five patients (58.38%) were in the intensive care unit. The main risk factors for candidemia were central venous catheter (CVC) (84.38%), previous surgical procedure (56.88%) and invasive mechanical ventilation (42.50%). Candida albicans was identified in 43.53% of isolates, followed by C. parapsilosis (31.76%) and C. glabrata (12.36%), C. krusei (5.29%), C. tropicalis (2.35%) and C. lusitaniae (2.35%). The study discovered a shift to non-albicansCandida species, particularly C. parapsilosis, and made it possible to determine the main tasks we should focus on to prevent candidemia in the hospital, these being mainly infection control measures directed towards prevention of catheter-related bloodstream infections, specifically comprising hand hygiene and CVC bundles of care. The potential benefit of fluconazole prophylaxis in certain populations of surgical patients could also be considered.

Extended-spectrum beta-lactamases and plasmid diversity in urinary isolates of Escherichia coli in Croatia: a nation-wide, multicentric, retrospective study.

In recent years, a dramatic increase in the prevalence of Escherichia coli strains producing extended-spectrum ß-lactamases (ESBLs) has been observed - both in the community and in healthcare settings. This multicentric study aimed to characterize ESBLs produced by E. coli isolates causing hospital-onset and community urinary tract infections, as well as to compare their antimicrobial sensitivity patterns, ß-lactamase content and plasmid types. Phenotypic tests for the detection of ESBLs and plasmid-mediated AmpC ß-lactamases were initially pursued, followed by molecular detection of resistance genes, plasmid characterization, genotyping with pulsed-field gel electrophoresis and whole genome sequencing (WGS). The isolates exhibited high level of resistance to expanded-spectrum cephalosporins (ESC) and carried CTX-M (cefotaximase-Munich) or TEM (Temoniera) ß-lactamases. All six representative isolates subjected to WGS belonged to the widespread clone ST131. In conclusion, our study demonstrated dissemination of group 1 CTX-M positive E. coli in different geographic regions of Croatia, but also different components of the health care systems (hospitals, nursing homes and the community) and confirmed the switch from SHV-2 (suphydril variant) and SHV-5 ESBLs to the nation-wide predominance of group 1 CTX-M ß-lactamases. Different plasmids were shown to be associated with the dissemination of blaCTX-M genes in different geographic regions of Croatia.

Clonal spread of carbapenem-resistant OXA-72-positive Acinetobacter baumannii in a Croatian university hospital.

BACKGROUND: From July to October 2008, 34 Acinetobacter baumannii isolates were involved in an outbreak at the Clinical Hospital Center, Zagreb. The aim of this study was to characterize the mechanisms of carbapenem resistance in our A. baumannii isolates and determine their epidemiology. METHODS: Antibiotic susceptibilities were determined by broth microdilution. PCR was used to detect the presence of carbapenemases. Genotyping of the isolates was performed by random amplification of polymorphic DNA (RAPD), pulsed-field gel electrophoresis (PFGE), and repetitive sequence-based PCR (rep-PCR). RESULTS: Thirty-three carbapenem-resistant isolates were positive for the acquired bla(OXA-72) and one unrelated isolate was positive for bla(OXA-58). The bla(OXA-72)-positive isolates were shown to be clonally related by RAPD, rep-PCR, and PFGE. CONCLUSIONS: On the basis of susceptibility testing, ß-lactamase characterization, and genotyping of the isolates we can conclude that clonal spread of endemic isolates was responsible for the high frequency of OXA-72-positive multidrug-resistant A. baumannii in this setting. Most of the isolates originated from the intensive care unit indicating local dissemination within the hospital and pointing to the potential source of isolates.