Browsing by Author "Jovanović, Snežana (7102384849)"

Clostridium (Clostridioides) difficile infections (CDIs) are among the most frequent healthcare-associated infections in Serbia. In 2013, Serbia participated in the European Clostridium difficile Infection Surveillance Network (ECDIS-Net) who launched a pilot study to enhance laboratory capacity and standardize surveillance for CDI. Two clinics of Clinical Center of Serbia [Clinic for Infectious and Tropical Diseases (CITD) and Clinic of Orthopedic Surgery and Traumatology (COT)] from Belgrade and one general hospital from another metropolitan area of Serbia, Užice, participated. During a period of 3 months in 2013, all patients with diagnosed CDI were included. The CDI incidence rates in CITD, COT, and General Hospital Užice were 19.0, 12.2, and 3.9 per 10,000 patient-days, respectively. In total, 49 patients were enrolled in the study with average age of 72 years. A complicated course of CDI was found in 14.3% of all patients. Six (12.2%) of 49 patients died, but not attributable to CDI. Of 39 C. difficile isolates, available for ribotyping, 78.9% belonged to ribotype 027; other PCR ribotypes were 001, 015, 002, 005, 010, 014, and 276. Antimicrobial susceptibility testing revealed low levels of MIC50 and MIC90 for metronidazole (0.5 μg/ml both) and vancomycin (0.25 and 0.5 μg/ml), while 28 strains of ribotype 027 were resistant to moxifloxacin with MIC ≥4 μg/ml. National surveillance is important to obtain more insight in the epidemiology of CDI and to compare the results with other European countries. This study by ECDIS-Net gives bases for a national surveillance of CDI in Serbia. © 2019 Akadémiai Kiadó, Budapest.

Clostridium (Clostridioides) difficile infections (CDIs) are among the most frequent healthcare-associated infections in Serbia. In 2013, Serbia participated in the European Clostridium difficile Infection Surveillance Network (ECDIS-Net) who launched a pilot study to enhance laboratory capacity and standardize surveillance for CDI. Two clinics of Clinical Center of Serbia [Clinic for Infectious and Tropical Diseases (CITD) and Clinic of Orthopedic Surgery and Traumatology (COT)] from Belgrade and one general hospital from another metropolitan area of Serbia, Užice, participated. During a period of 3 months in 2013, all patients with diagnosed CDI were included. The CDI incidence rates in CITD, COT, and General Hospital Užice were 19.0, 12.2, and 3.9 per 10,000 patient-days, respectively. In total, 49 patients were enrolled in the study with average age of 72 years. A complicated course of CDI was found in 14.3% of all patients. Six (12.2%) of 49 patients died, but not attributable to CDI. Of 39 C. difficile isolates, available for ribotyping, 78.9% belonged to ribotype 027; other PCR ribotypes were 001, 015, 002, 005, 010, 014, and 276. Antimicrobial susceptibility testing revealed low levels of MIC50 and MIC90 for metronidazole (0.5 μg/ml both) and vancomycin (0.25 and 0.5 μg/ml), while 28 strains of ribotype 027 were resistant to moxifloxacin with MIC ≥4 μg/ml. National surveillance is important to obtain more insight in the epidemiology of CDI and to compare the results with other European countries. This study by ECDIS-Net gives bases for a national surveillance of CDI in Serbia. © 2019 Akadémiai Kiadó, Budapest.

Objectives: In humans, enterococci are among the most important opportunistic pathogens. This study aims to compare invasive isolates obtained from blood cultures of patients with sepsis and endocarditis with colonizing isolates obtained from healthy donors’ stool samples. Methods: A case-by-case assessment was conducted on invasive infection cases to determine whether enterococci were involved in their pathogenesis. They were tested for the presence of virulence factor genes, β-hemolysis on agars supplemented with human and sheep blood, and biofilm forming capacity. Results: Three species of enterococci were identified among invasive isolates: Enterococcus faecalis, Enterococcus faecium, and Enterococcus durans. All endocarditis isolates were biofilm producers. Genes esp, gelE, asa1, ace, hyl, cylB, and cylA were present in 7 (41.2%), 11 (64.7%), 11 (64.7%), 13 (76.5%), 0, 3 (17.6%), and 1 (5.9%) invasive isolate, but none of them could be linked to a particular infection (sepsis or endocarditis). Colonizing isolates proved to have had more virulence factor genes, but the differences were not statistically significant. Members of that group produced a greater amount of biofilm when the ace gene was absent (p = 0.047). The production of β-hemolysis by noninvasive strains was detected more frequently when agar was supplemented with human blood (p = 0.021). In general, the presence of either cyl gene on that specific agar was in direct connection with the production of β-hemolysis: cylA (p = 0.047) or cylB (p = 0.020). Conclusion: We have been unable to establish any correlation between invasive isolates and any virulence gene carriage and biofilm formation. β-hemolysis was produced significantly more often by colonizing strains when agar had been supplemented with human blood. © The Author(s) 2023.

Objectives: In humans, enterococci are among the most important opportunistic pathogens. This study aims to compare invasive isolates obtained from blood cultures of patients with sepsis and endocarditis with colonizing isolates obtained from healthy donors’ stool samples. Methods: A case-by-case assessment was conducted on invasive infection cases to determine whether enterococci were involved in their pathogenesis. They were tested for the presence of virulence factor genes, β-hemolysis on agars supplemented with human and sheep blood, and biofilm forming capacity. Results: Three species of enterococci were identified among invasive isolates: Enterococcus faecalis, Enterococcus faecium, and Enterococcus durans. All endocarditis isolates were biofilm producers. Genes esp, gelE, asa1, ace, hyl, cylB, and cylA were present in 7 (41.2%), 11 (64.7%), 11 (64.7%), 13 (76.5%), 0, 3 (17.6%), and 1 (5.9%) invasive isolate, but none of them could be linked to a particular infection (sepsis or endocarditis). Colonizing isolates proved to have had more virulence factor genes, but the differences were not statistically significant. Members of that group produced a greater amount of biofilm when the ace gene was absent (p = 0.047). The production of β-hemolysis by noninvasive strains was detected more frequently when agar was supplemented with human blood (p = 0.021). In general, the presence of either cyl gene on that specific agar was in direct connection with the production of β-hemolysis: cylA (p = 0.047) or cylB (p = 0.020). Conclusion: We have been unable to establish any correlation between invasive isolates and any virulence gene carriage and biofilm formation. β-hemolysis was produced significantly more often by colonizing strains when agar had been supplemented with human blood. © The Author(s) 2023.

Background: Hospital-acquired infections (HAIs) are a global public health problem and put patients at risk of complications, including death. HAIs increase treatment costs, but their financial impact on Serbia’s healthcare system is unknown. Our goal was to assess incremental costs of HAIs in a tertiary care adult intensive care unit (ICU) that managed COVID-19 patients. Methods: A retrospective study from March 6th to December 31st, 2020 included patients with microbiologically confirmed COVID-19 (positive rapid antigen test or real-time polymerase chain reaction) treated in the ICU of the Teaching Hospital for Infectious and Tropical Diseases, University Clinical Centre of Serbia. Demographic and HAI-specific data acquired in our ICU were collected, including total and stratified medical costs (services, materials, laboratory testing, medicines, occupancy costs). Median total and stratified costs were compared in relation to HAI acquisition. Linear regression modelling was used to assess incremental costs of HAIs, adjusted for age, biological sex, prior hospitalisation, Charlson Comorbidity Index (CCI), and Glasgow Coma Scale (GCS) on admission. Outcome variables were length of stay (LOS) in days and mortality. Results: During the study period, 299 patients were treated for COVID-19, of which 214 were included. HAIs were diagnosed in 56 (26.2%) patients. Acinetobacter spp. was the main pathogen in respiratory (38, 45.8%) and bloodstream infections (35, 42.2%), the two main HAI types. Median total costs were significantly greater in patients with HAIs (€1650.4 vs. €4203.2, p < 0.001). Longer LOS (10.0 vs. 18.5 days, p < 0.001) and higher ICU mortality (51.3% vs. 89.3%, p < 0.001) were seen if HAIs were acquired. Patients with ≥ 2 HAIs had the highest median total costs compared to those without HAIs or with a single HAI (€1650.4 vs. €3343.4 vs. €7336.9, p < 0.001). Incremental costs in patients with 1 and ≥ 2 HAIs were €1837.8 (95% CI 1257.8–2417.7, p < 0.001) and €5142.5 (95% CI 4262.3–6022.7, p < 0.001), respectively. Conclusions: This is the first economic evaluation of HAIs in Serbia, showing significant additional costs to our healthcare system. HAIs prolong LOS and influence ICU mortality rates. Larger economic assessments are needed to enhance infection control practices. © 2023, The Author(s).

Introduction: In an intensive care unit (ICU) of the Emergency Center in the Clinical Center of Serbia, four species of vancomycin resistant enterococci (VRE) were isolated in a 17-month period mostly from blood cultures, including E. faecalis, E. faecium, E. raffinosus and E.gallinarum. Methodology: The relationship between isolates from each species was investigated by PFGE, and PCR experiments for detection of pathogenicity factor genes and van genes to determine the nature of each clone. A PCR-based method, using 10 primer pairs (p1/2-p19/20), was used to investigate the presence of the Tn1546-like structure. Results: PFGE indicated the presence of two different E. faecium clones, while the three other enterococcal species belonged to one clone each. Transposon typing revealed that isolates of E. raffinosus (4), E. gallinarum (4) and E. faecalis (3) yielded gene sequences identical to 10 primer pairs (p1/2-p19/20), suggesting the possibility of identical transposon-like structure in these species. Conclusions: The results of the study indicate probable horizontal spread of Tn1546-like structure in three species of VRE obtained from the same ICU. © 2017 Jovanović et al.

Introduction: In an intensive care unit (ICU) of the Emergency Center in the Clinical Center of Serbia, four species of vancomycin resistant enterococci (VRE) were isolated in a 17-month period mostly from blood cultures, including E. faecalis, E. faecium, E. raffinosus and E.gallinarum. Methodology: The relationship between isolates from each species was investigated by PFGE, and PCR experiments for detection of pathogenicity factor genes and van genes to determine the nature of each clone. A PCR-based method, using 10 primer pairs (p1/2-p19/20), was used to investigate the presence of the Tn1546-like structure. Results: PFGE indicated the presence of two different E. faecium clones, while the three other enterococcal species belonged to one clone each. Transposon typing revealed that isolates of E. raffinosus (4), E. gallinarum (4) and E. faecalis (3) yielded gene sequences identical to 10 primer pairs (p1/2-p19/20), suggesting the possibility of identical transposon-like structure in these species. Conclusions: The results of the study indicate probable horizontal spread of Tn1546-like structure in three species of VRE obtained from the same ICU. © 2017 Jovanović et al.

Background: The incidence of Clostridium difficile infections (CDI) in the Clinical Center of Serbia (CCS) and the entire Serbia has been constantly rising in the previous 5 years. We aimed to study C. difficile PCR-ribotypes isolated from patients hospitalized at two healthcare institutions: CCS and Specialized Hospital for Cerebrovascular Diseases “Sveti Sava” (SS), both of them from Belgrade, and to investigate the incidence rates of CDI in hospital settings in Serbia, from 2009 to 2013. Methods: The Bacteriology laboratory database at Clinic for Infectious and Tropical Diseases of CCS was queried from January 1, 2009 to December 31, 2013 for all patients who underwent immunochromatographic toxin A and/or toxin B stool testing and C. difficile stool culture for suspected infection caused by this bacterium. Toxigenic culture was not performed. Ninety- six C. difficile isolates were then selected and characterized by PCR-ribotyping. These were obtained from 94 patients hospitalized in different clinics of CCS and SS from November 2011 to December 2013. Results: Among 6164 stool samples sent to Bacteriology laboratory for culture of C. difficile and toxin detection during the study period, 1775 (28.8%) were positive, displaying linear trend of growth. From 96 isolates, typed by PCR-ribotyping, majority (85; 88.54%) belonged to PCR-ribotype 027. The remaining 11 isolates belonged to PCR-ribotypes 014/020 (3 isolates), 015, SLO 191 (two isolates each), 017, 018, 070 and 001/072 (one isolate each). Conclusion: Our results demonstrated that C. difficile PCR-ribotype 027 is by far predominant in two hospital settings in Belgrade, at least since 2011. © 2018 Elsevier Ltd

Background: The incidence of Clostridium difficile infections (CDI) in the Clinical Center of Serbia (CCS) and the entire Serbia has been constantly rising in the previous 5 years. We aimed to study C. difficile PCR-ribotypes isolated from patients hospitalized at two healthcare institutions: CCS and Specialized Hospital for Cerebrovascular Diseases “Sveti Sava” (SS), both of them from Belgrade, and to investigate the incidence rates of CDI in hospital settings in Serbia, from 2009 to 2013. Methods: The Bacteriology laboratory database at Clinic for Infectious and Tropical Diseases of CCS was queried from January 1, 2009 to December 31, 2013 for all patients who underwent immunochromatographic toxin A and/or toxin B stool testing and C. difficile stool culture for suspected infection caused by this bacterium. Toxigenic culture was not performed. Ninety- six C. difficile isolates were then selected and characterized by PCR-ribotyping. These were obtained from 94 patients hospitalized in different clinics of CCS and SS from November 2011 to December 2013. Results: Among 6164 stool samples sent to Bacteriology laboratory for culture of C. difficile and toxin detection during the study period, 1775 (28.8%) were positive, displaying linear trend of growth. From 96 isolates, typed by PCR-ribotyping, majority (85; 88.54%) belonged to PCR-ribotype 027. The remaining 11 isolates belonged to PCR-ribotypes 014/020 (3 isolates), 015, SLO 191 (two isolates each), 017, 018, 070 and 001/072 (one isolate each). Conclusion: Our results demonstrated that C. difficile PCR-ribotype 027 is by far predominant in two hospital settings in Belgrade, at least since 2011. © 2018 Elsevier Ltd

Objectives: Antibiotic use and immunocompromised status in haematology patients have been shown to determine the constituents of commensal microbiota with highly increased resistance, including vancomycin resistant enterococci. We compared the carriage of virulence factor genes and the capacity for biofilm formation in vancomycin resistant enterococci (VRE) originating from the oropharyngeal and stool cultures of haematology patients. Design: PCR tests were used to investigate the presence of genes encoding pathogenicity factors (esp and hyl) in VRE isolates. The genotype of vancomycin resistance was investigated by multiplex PCR tests for vanA and vanB genes. PFGE typing was conducted to exclude the duplicate isolates. Results: Of 3310 pharyngeal swabs taken from inpatients at a clinic for haematology, Enterococcus species were recovered in 6.46%. All VRE investigated were identified as Enterococcus faecium and were highly vancomycin resistant. VanA genotype was confirmed in all. In the group of oropharyngeal carriers (n = 8 patients), 15 strains were recovered from oropharyngeal specimens and PFGE typing revealed 5 types and 3 subtypes. Identical types of VRE in the oropharynx and stool cultures were found in three patients from this group. In the group of stool carriers (n = 24 patients) VRE were obtained from stools only and placed in 21 macro-restriction patterns. The esp gene was more common in VRE isolated from the oropharynx than in isolates from stools (p = 0.014). Results were not significant when we compared the presence of hyl genes in oropharyngeal isolates with those from stool cultures (p = 0.66) or when we investigated the association between esp and hyl gene carriage and capability of biofilm formation in non-repeated VRE. Conclusions: In the present study, isolation of VRE from the oropharynx in haematology patients was associated with esp gene carriage. Further research is needed to investigate the clinical and long-term effects of this finding. © 2018 Elsevier Ltd

Objectives: Antibiotic use and immunocompromised status in haematology patients have been shown to determine the constituents of commensal microbiota with highly increased resistance, including vancomycin resistant enterococci. We compared the carriage of virulence factor genes and the capacity for biofilm formation in vancomycin resistant enterococci (VRE) originating from the oropharyngeal and stool cultures of haematology patients. Design: PCR tests were used to investigate the presence of genes encoding pathogenicity factors (esp and hyl) in VRE isolates. The genotype of vancomycin resistance was investigated by multiplex PCR tests for vanA and vanB genes. PFGE typing was conducted to exclude the duplicate isolates. Results: Of 3310 pharyngeal swabs taken from inpatients at a clinic for haematology, Enterococcus species were recovered in 6.46%. All VRE investigated were identified as Enterococcus faecium and were highly vancomycin resistant. VanA genotype was confirmed in all. In the group of oropharyngeal carriers (n = 8 patients), 15 strains were recovered from oropharyngeal specimens and PFGE typing revealed 5 types and 3 subtypes. Identical types of VRE in the oropharynx and stool cultures were found in three patients from this group. In the group of stool carriers (n = 24 patients) VRE were obtained from stools only and placed in 21 macro-restriction patterns. The esp gene was more common in VRE isolated from the oropharynx than in isolates from stools (p = 0.014). Results were not significant when we compared the presence of hyl genes in oropharyngeal isolates with those from stool cultures (p = 0.66) or when we investigated the association between esp and hyl gene carriage and capability of biofilm formation in non-repeated VRE. Conclusions: In the present study, isolation of VRE from the oropharynx in haematology patients was associated with esp gene carriage. Further research is needed to investigate the clinical and long-term effects of this finding. © 2018 Elsevier Ltd

Legionella pneumophila is a rarely diagnosed microorganism in Serbia. It causes legionellosis, usually a mild respiratory infection. However, in some cases it can be severe and even life threatening. In June 2020, during the COVID-19 pandemic, a patient with symptoms of the aforesaid infection, namely severe pneumonia and acute respiratory distress syndrome, was admitted to the hospital. The multiplex polymerase chain reaction (PCR) test (The BioFire FilmArray Pneumonia Panel plus) detected the presence of L. pneumophila in the patient’s bronchial secretions. The specific culture for the detection of that organism, however, remained sterile. The patient’s paired sera had been sent for serology and the results in both of them came back positive for Legionella spp. 1–6, while the assays specific for each one of the 10 serogroups detected more than a fourfold increase of antibody titers in an uncommon serogroup 2 only. The patient was treated with moxifloxacin; he recovered well and was discharged after 26 days of hospitalization. Having being diagnosed with the L. pneumophila infection correctly through the multiplex PCR test, the patient was given the right therapy with moxifloxacin. The serologic assays corroborated this result and revealed the uncommon group 2, thus confirming the necessity of carrying out all the tests available to attain the exact diagnosis of legionellosis. © The Author(s) 2022.

Legionella pneumophila is a rarely diagnosed microorganism in Serbia. It causes legionellosis, usually a mild respiratory infection. However, in some cases it can be severe and even life threatening. In June 2020, during the COVID-19 pandemic, a patient with symptoms of the aforesaid infection, namely severe pneumonia and acute respiratory distress syndrome, was admitted to the hospital. The multiplex polymerase chain reaction (PCR) test (The BioFire FilmArray Pneumonia Panel plus) detected the presence of L. pneumophila in the patient’s bronchial secretions. The specific culture for the detection of that organism, however, remained sterile. The patient’s paired sera had been sent for serology and the results in both of them came back positive for Legionella spp. 1–6, while the assays specific for each one of the 10 serogroups detected more than a fourfold increase of antibody titers in an uncommon serogroup 2 only. The patient was treated with moxifloxacin; he recovered well and was discharged after 26 days of hospitalization. Having being diagnosed with the L. pneumophila infection correctly through the multiplex PCR test, the patient was given the right therapy with moxifloxacin. The serologic assays corroborated this result and revealed the uncommon group 2, thus confirming the necessity of carrying out all the tests available to attain the exact diagnosis of legionellosis. © The Author(s) 2022.