Biofilm-producing Bacteria and Quality of Life after Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis with Nasal Polyposis.

BACKGROUND: Chronic rhinosinusitis (CRS) is one of the most common health disorders in humans and has a major impact on health-related quality of life (HRQoL). Of the many factors contributing to the etiology of CRS, less is known about the correlation between CRS and bacterial biofilms and their impact on HRQoL. OBJECTIVE: The aim of this prospective study was to investigate the relationship between biofilm-producing bacteria and patients' objective findings and HRQoL. METHODS: Forty-eight patients with CRSwNP were enrolled in a 12-month prospective study. The Lund-Mackay (LM) CT and endoscopic Lund-Kennedy (LK) scores were obtained before endoscopic sinus surgery (ESS), and patients completed the HRQoL instruments: the 22-item Sinonasal Outcome Test (SNOT-22), the 36-item Short Questionnaire (SF-36), and the visual analog scale (VAS). A sinus culture was obtained at ESS, bacteria were isolated, and in vitro quantification of the biofilm was performed. The LK score and HRQoL were determined postoperatively at months 1, 3, 6, and 12. RESULTS: The most common bacterial isolates in patients with CRSwNP were Staphylococcus aureus (28%), coagulase-negative staphylococci (52%), and Pseudomonas aeruginosa (8%). Preoperatively, the highest LM and LK scores were found in patients with strong biofilm producers. Postoperative LK scores were significantly reduced in all patients. Postoperative VAS scores were significantly reduced from month 1 to month 12 postoperatively. Patients with strong biofilm producers had significantly worse nasal blockage, secretion, headache, facial pressure and pain, and loss of smell preoperatively, compared to patients with low biofilm producers. The most significant reduction in preoperative scores SNOT-22 and SF-36 (excluding physical functioning) was seen in patients with S. aureus and P. aeruginosa. CONCLUSIONS: Patients with strong biofilm producers had higher LK and LM scores preoperatively, and greater improvement in LK and HRQoL scores postoperatively. Microbiologic surveillance of all CRS patients is recommended.

Plasma Concentrations of Rosmarinic Acid in Patients on Antiretroviral Therapy: In Silico Exploration Based on Clinical Data.

Rosmarinic acid (RA) is a phenolic compound with antiviral properties, often encountered in dietary supplements and herbal drugs. Data on the pharmacokinetics of RA are lacking in cases of the chronic use of supplements containing this compound, and only limited data on the metabolism and distribution of RA are available. The aim of the study was to investigate the plasma levels of RA after 12 weeks of use and determine potential interactions of RA and selected antiretroviral drugs. Patients infected with human immunodeficiency virus took a supplement containing RA for 12 weeks, after which the RA concentrations in the plasma samples were analyzed. A detailed in silico analysis was conducted in order to elucidate the potential interactions between RA and the drugs efavirenz, darunavir and raltegravir. It was found that RA can be detected in patients' plasma samples, mainly in the form of sulphoglucuronide. The potential interactions are suggested on the level of liver metabolizing enzymes and efflux P-glycoprotein, with RA competing with antiretroviral drugs as a substrate in metabolism and distribution systems. The present study suggests that the simultaneous use of RA and antiretroviral therapy (containing efavirenz, darunavir or raltegravir) may affect the plasma levels of RA after prolonged supplementation.

Sagittal Abdominal Diameter as the Best Predictor of Metabolic Syndrome in HIV-Infected Men on Antiretroviral Therapy.

BACKGROUND: The interaction of human immunodeficiency virus (HIV), host and antiretroviral therapy causes a range of metabolic disorders that can be characterized as a metabolic syndrome (MetS) that increases the cardiovascular risk. MetS involves central obesity, which can be detected using different anthropometric parameters. OBJECTIVE: To assess the abilities of different anthropometric parameters in the prediction of MetS in HIV-infected men on ART. METHOD: The study involved 92 male participants (mean age 44.46±10.38 years), divided into two groups: with and without MetS. All subjects underwent biochemical evaluation (triglycerides, HDL-cholesterol, fasting glucose), blood pressure measurement and anthropometric assessment: body mass, body height, body mass index (BMI), body fat mass, body circumferences (chest, upper arm, forearm, waist, hip, proximal and middle thigh and calf), sagittal abdominal diameter (SAD), skinfold thicknesses (subscapular, anterior and posterior upper arm, anterior and lateral forearm, abdominal, supraspinal, thigh and calf), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist-to-thigh ratio (WTR), sagittal abdominal diameter-to-body height ratio (SADH), body adiposity index (BAI) and conicity index. MetS was specified according to IDF criteria. RESULTS: Subjects with MetS had statistically significant higher values of all anthropometric parameters except middle thigh circumference, calf skinfold and body height. According to ROC analysis and Binary Logistic Regression, SAD has been shown as the best predictor of MetS with a predictive value of 21.40 cm (AUC:0.91), followed by WHR with a predictive value of 0.93. CONCLUSION: Sagittal abdominal diameter is the strongest anthropometric indicator of MetS in HIV-infected patients on ART.

Influence of physical activity on endothelial function in people living with HIV.

INTRODUCTION: Decreased physical activity is a major cardiovascular risk factor that is particularly pronounced in people living with HIV (PLHIV), who are more susceptible to endothelial dysfunction and accelerated atherosclerosis than the general population due to multiple mechanisms. The aim of the present study was to analyse whether regular physical activity is capable of improving endothelial function measured by flow-mediated dilatation (FMD) in PLHIV. METHODS: We performed FMD measurement in 38 PLHIV, along with the assessment of their regular physical activity level using the International Physical Activity Questionnaire (IPAQ). RESULTS: Flow-mediated dilatation results in PLHIV were 0.31 ± 0.06 mm and 7.34% ± 1.41% for absolute and relative FMD, respectively. IPAQ results showed that the average weekly level of physical activity was 3631.1 ± 1526.7 MET-min/week, whereas the average daily sitting time was 287.3 ± 102.7 min/day. Predictors jointly accounted for 48% (adjusted value 42%) of FMD variance. Bootstrapped confidence levels revealed that physical activity had a statistically significant effect on the outcome [beta = 0.517, 2.5% confidence interval (CI) = 0.205, 97.5% CI = 0.752]. CONCLUSION: Physical activity represents a widely available and uncostly tool that is capable of improving endothelial function and overall cardiovascular health in PLHIV.

Effect of Nonsurgical Periodontal Treatment on Salivary and Plasma Superoxide Dismutase Levels of Patients Suffering from Periodontitis.

Antioxidant capacity is frequently measured by evaluating superoxide dismutase (SOD) concentration in body fluids. The aim of this study was to compare SOD concentrations in the saliva and plasma of patients with periodontitis to those measured in a group of patients with healthy periodontium, as well as to evaluate the influence of nonsurgical periodontal therapy on salivary and plasma SOD in periodontitis patients. For this purpose, 40 systemically healthy patients aged 30-70 years who had at least 20 teeth were recruited, 20 of whom had periodontitis, and 20 served as healthy periodontitis-free controls. In all participants, periodontal status was assessed via the plaque index (PI), gingival index (GI), papilla bleeding index (PIB), probing depth (PD), and clinical attachment level (CAL), and the SOD concentration in both saliva and plasma was determined by conducting a commercial immunoenzymatic ELISA test. In periodontitis patients, periodontal indices and saliva and blood samples were taken at the beginning of the study, as well as 3 months after periodontal therapy, while in the control group, these data were gathered at the beginning of the study only. SOD values in the saliva of patients with periodontitis (0.244 U/µL) were statistically significantly higher compared with patients with healthy periodontium (0.017 U/µL). Moreover, periodontal therapy led to a statistically significant decrease in this marker in the saliva of patients with periodontitis (p = 0.023), which was comparable with that measured in the control group. On the other hand, no statistically significant differences were noted in plasma SOD values either between the two groups or at follow-up compared with baseline in the group with periodontitis. These findings suggest that the elevated salivary SOD in patients with periodontal disease may represent a mechanism of tissue protection against oxidative stress that occurs in response to periodontal disease.

Carbapenemase-producing Klebsiella pneumoniae in community settings: a cross-sectional study in Belgrade, Serbia.

Aim: The types of carbapenemases and clonal relatedness among community isolates of carbapenemase-producing Klebsiella pneumoniae in Belgrade, Serbia, were determined. Materials & methods: During the period 2016-2020, K. pneumoniae community isolates were screened for carbapenemases, and carbapenemase production was confirmed by multiplex PCR. Clonality was determined based on genetic profiles obtained by enterobacterial repetitive intergenic consensus PCR. Results: Carbapenemase genes were detected in 114 of 4800 isolates (2.4%). The most frequent gene was blaOXA-48-like. Most isolates (70.5%) were grouped in ten clusters. Cluster 11 contained 16.4% of all blaOXA-48-like-positive isolates, and all blaKPC-positive isolates were grouped in one cluster. Conclusion: Laboratory-based detection and surveillance are highly recommended in order to control the spread of resistance in community settings.

The main threat of antimicrobial resistance is the ability of bacteria to exchange the genetic material on mobile genetic elements. Carbapenemases are a group of proteins that confer resistance to carbapenem antibiotics and their genes are commonly carried on mobile genetic elements. Five of these proteins have the greatest clinical importance: KPC, VIM, IMP, NDM and OXA-48. Serbia has one of the highest levels of carbapenemase-producing Klebsiella pneumoniae among hospital isolates in Europe, but there are no available data for community isolates. Thus, we analyzed K. pneumoniae isolates from community patients in Belgrade, Serbia. There was no difference between the number of isolates with carbapenemases in comparison with other European regions where similar studies have been conducted. The predominant carbapenemase among community isolates of K. pneumoniae in our study was OXA-48. In previous studies in our country, NDM carbapenemase was the most prevalent among both community and hospital isolates. This is in accordance with the endemicity of NDM enzymes in Balkan countries, but our results suggest that there could be changes in the molecular epidemiology of carbapenemases in Serbia, which should be confirmed by future research.

CNS efficacy parameters of combination antiretroviral therapy in chronic HIV infection: A multi-voxel magnetic resonance spectroscopy study.

This study aimed to determine the correlations of combination antiretroviral therapy (cART) efficacy parameters in the central nervous system (CNS) with a neurometabolic profile on magnetic resonance spectroscopy (MRS) in virally suppressed, neurologically asymptomatic HIV+ individuals. In total, 32 HIV+ individuals on stable cART with an average age of 41.97 ± 10.12 years and with available clinical data, CNS penetration effectiveness (CPE), and monocyte efficacy (ME) scores underwent multi-voxel MRS. The parameters of neuronal number/function (NAA/Cr), membrane turnover (Cho/Cr), and glial proliferation (mI/Cr) were analyzed in supratentorial white and gray matter. Correlations of CPE and ME with neurometabolic ratios were performed using Pearson's correlation test. Statistical significance was set at p < 0.05. A strong positive correlation was observed between Cho/Cr and CPE in the left parietal subcortical white matter (r = 0.577, p = 0.001). A strong positive correlation between NAA/Cr and ME was obtained in the left (r = 0.521, p = 0.003) and the right (r = 0.494, p = 0.005) posterior cingulate. A strong negative correlation between ME and Cho/Cr ratios was observed in the right frontal deep white matter (r = -0.569, p = 0.001). Indices designed to assess cART efficacy in CNS failed to present significant correlations with the neurometabolic profile obtained using MRS. There is a need to define more potent non-invasive tools for neuroinflammation assessment given the prolonged life expectancy in the HIV+ population.

Staphylococcal biofilm on wedding rings worn by laboratory workers.

Hands of healthcare workers play essential role in the spreading of antimicrobial-resistant microorganisms in and out of the healthcare settings. Less is known about the role of laboratory workers (LWs). The aim of our study was to evaluate the presence of biofilm-forming staphylococci on the surface of jewelry rings of LWs and their antimicrobial susceptibility pattern.A total of 79 LWs from eight different microbiology laboratories that process and analyze specimens from the tertiary care hospitals in Belgrade, Serbia participated in the study. The study was reviewed and approved by the institutional review boards at hospitals. Samples were taken after hand washing. Bacteria on LWs wedding rings were detected with the rolling method, and further analyzed in order to determine the number of colony forming unit (CFU) per ring, species of bacteria and their antimicrobial susceptibility pattern, methicillin resistance and biofilm-producing capacity in vitro.Staphylococci were recovered from 60.8% of wedding rings. All strains produced biofilm (25% weak, 56.2% moderate and 18.8% large amount), with significant difference between species (P < 0.001). Staphylococcus aureus and Staphylococcus epidermidis formed the largest amount of biofilm and had the largest number of CFU per ring. Staphylococci were most commonly resistant to penicillin (66.7%), tetracycline (50.0%), and erythromycin (45.8%); 41.7% of isolates was multidrug resistant and mecA gene was detected in five strains. All strains were susceptible to linezolid, vancomycin, teicoplanin and tigecycline.Staphylococci colonize LWs wedding rings, form biofilm on it, have multidrug resistant phenotype and/or carry mecA gene, representing a significant reservoir for the spreading of microorganisms and resistance. As far as we know, our study is the first that address this topic in laboratory workers.

Intestinal Colonization of Preterm Neonates with Carbapenem Resistant Enterobacteria at Hospital Discharge.

Our aim was to investigate gut colonization with carbapenem-resistant Enterobacterales (CRE) in the population of preterm neonates at discharge from a tertiary care center in Serbia. The study included 350 randomly selected neonates/infants discharged in the period April 2018-May 2019. CRE colonization was present in 88/350 (25.1%) of patients. Klebsiella pneumoniae producing KPC and OXA-48 carbapenemase were detected in 45 and 42 subjects, respectively, while NDM producing Escherichia coli was identified in one patient only. All OXA-48 strains harbored blaCTX-M-15, while both blaTEM and blaSHV were present in all but one KPC-producing strain. CRE isolates exhibited a multidrug resistance pattern with uniform fluoroquinolone resistance, universal susceptibility to colistin, and variable susceptibility to aminoglycosides. Administration of carbapenems was common (~50%) and it was strongly associated with colonization, as well as the combinational therapeutic regimens that included meropenem, contrary to ampicillin-sulbactam/colistin therapy and prolonged course of the initial therapy (ampicillin/amikacin ≥ 7 days). Other risk factors for CRE carriage were level of immaturity, admission to neonatal intensive care unit, prolonged hospitalization and invasive procedures. Although the rate of clinically and/or laboratory proven systemic infections was significantly higher among colonized patients, CRE infection was confirmed in one patient only (1.1%) that was colonized with NDM E. coli. Clonal relatedness of CRE isolates was high, with seven and eight clusters detected among KPC (N = 30) and OXA-48 (N = 37) producing strains, respectively. The follow up of the 31 KPC-colonized patients after discharge from hospital revealed common decolonization within one month (~68%). In conclusion, our results demonstrated a high rate of CRE colonization that is most likely related to carbapenem consumption and lack of screening as important infection prevention practice.

Whole-Genome Sequencing Snapshot of Clinically Relevant Carbapenem-Resistant Gram-Negative Bacteria from Wastewater in Serbia.

Wastewater (WW) is considered a source of antibiotic-resistant bacteria with clinical relevance and may, thus, be important for their dissemination into the environment, especially in countries with poor WW treatment. To obtain an overview of the occurrence and characteristics of carbapenem-resistant Gram-negative bacteria (CR-GNB) in WW of Belgrade, we investigated samples from the four main sewer outlets prior to effluent into international rivers, the Sava and the Danube. Thirty-four CR-GNB isolates were selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS). AST revealed that all isolates were multidrug-resistant. WGS showed that they belonged to eight different species and 25 different sequence types (STs), seven of which were new. ST101 K. pneumoniae (blaCTX-M-15/blaOXA-48) with novel plasmid p101_srb was the most frequent isolate, detected at nearly all the sampling sites. The most frequent resistance genes to aminoglycosides, quinolones, trimethroprim-sulfamethoxazole, tetracycline and fosfomycin were aac(6')-Ib-cr (55.9%), oqxA (32.3%), dfrA14 (47.1%), sul1 (52.9%), tet(A) (23.5%) and fosA (50%), respectively. Acquired resistance to colistin via chromosomal-mediated mechanisms was detected in K. pneumoniae (mutations in mgrB and basRS) and P. aeruginosa (mutation in basRS), while a plasmid-mediated mechanism was confirmed in the E. cloacae complex (mcr-9.1 gene). The highest number of virulence genes (>300) was recorded in P. aeruginosa isolates. Further research is needed to systematically track the occurrence and distribution of these bacteria so as to mitigate their threat.

Evaluation of Lipid Peroxidation in the Saliva of Diabetes Mellitus Type 2 Patients with Periodontal Disease.

As oxidative stress has been implicated in the pathogenesis of diabetes mellitus and periodontitis, it may serve as a link between these conditions. Therefore, as a part of the present study, salivary lipid peroxidation (LP) in periodontitis patients with and without diabetes mellitus type 2 (DM2) was evaluated, along with the periodontal therapy effectiveness. The study sample comprised of 71 DM2 patients with periodontitis and 31 systemically healthy controls suffering from periodontitis of comparable severity. In all participants, periodontal indices­plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL)­were recorded, and salivary LP was measured using a spectrophotometric method prior to treatment initiation and three months post-treatment. At baseline, mean salivary LP in DM2 patients was higher than that measured for the control group, but the difference did not reach statistical significance (p > 0.05), whereas a positive significant correlation was found between PPD and LP in both groups. Three months after nonsurgical periodontal therapy, clinical periodontal parameters and salivary LP levels were significantly reduced in both groups (p < 0.05). These findings indicate that the improvement in clinical periodontal status following nonsurgical periodontal therapy is accompanied by a significant decrease in salivary LP in DM2 patients, suggesting that periodontitis, rather than diabetes, is the primary driver of the elevated salivary LP in this group.

COVID-19 Breakthrough Infections among Patients Aged ≥65 Years in Serbia: Morbidity and Mortality Overview.

BACKGROUND: Vaccines against severe acute respiratory syndrome coronavirus 2 have shown effectiveness in the prevention of COVID-19. Breakthrough infections occur, and age has been shown to be one of the dominant risk factors for poorer outcome. This research focuses on characteristics of breakthrough infections in older adults. METHODS: This retrospective study was conducted for four months (March−June 2021) in the autonomous province of Vojvodina in Serbia on 11,372 patients using reverse-transcription polymerase chain reaction or antigen-detection rapid diagnostic tests verifying COVID-19 in those aged ≥65 years. Demographics, comorbidities, disease severity, and final outcomes were evaluated in fully vaccinated compared to unvaccinated individuals. Individuals were divided into younger-old (65−74 years) and older-old (≥75 years) age groups and differences between those groups were further evaluated. Binary logistic regression was performed to identify independent predictors of poor outcome. RESULTS: By the end of the research, 51.3% of the population of APV 65−74 years, as well as 46.2% of those older than 74 years, were vaccinated. From the acquired sample, 17.4% had breakthrough infection. Asymptomatic forms were higher in both age groups of vaccinated vs. unvaccinated (3.9%­younger-old, 6.3%­older-old vs. 2.9%­younger-old, 3.9%­older-old). The same results were registered with mild symptoms (82.1%­younger-old, 68.1%­older-old vs. 76.3%­younger-old, 57.5%­older-old) (p < 0.001). The case fatality ratio of the vaccinated population was smaller than the unvaccinated population in both groups (3.1% vs. 7.9%­younger-old; 11.4% vs. 22.5%­older-old) (p < 0.001). The odds ratio for poor outcome in unvaccinated individuals was 2.3 (95% confidence interval, p < 0.001) for the total sample. CONCLUSIONS: An increase in asymptomatic and mild forms, as well as decrease in severe or critical forms and poor outcomes, were noted in the vaccinated population. Choosing to avoid vaccination against SARS-CoV-2 may increase the chance of poor outcome in older individuals.

Effects of Nonsurgical Periodontal Therapy on Salivary 8-Hydroxy-Deoxyguanosine Levels and Glycemic Control in Diabetes Mellitus Type 2 Patients.

Diabetes and periodontitis are complex chronic diseases that are potentially interrelated, as well as associated with oxidative stress. Thus, the aim of the present study was to evaluate the influence of nonsurgical periodontal treatment on salivary 8-hydroxy-deoxyguanosine (8-OHdG) levels and glycemic control in patients suffering from both diabetes mellitus type 2 (DM2) and periodontitis. The study sample included 53 DM2 patients, while 31 systemically healthy patients served as controls. Participants in both groups suffered from periodontitis of comparable severity. Periodontal clinical parameters, namely plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, along with salivary 8-OHdG levels and glycated hemoglobin (HbA1c). Levels of 8-OHdG were analyzed by ELISA. All aforementioned parameters were evaluated prior to commencing the study and at 90-day follow-up upon nonsurgical periodontal therapy completion. At baseline, salivary levels of 8-OHdG in DM2 patients were significantly higher (1.17 ng/mL) than those measured for the control group (0.75 ng/mL) and showed significant positive correlation with GI and PPD (p < 0.05). Three months after nonsurgical periodontal therapy, the salivary 8-OHdG levels were significantly reduced in DM2 patients (p < 0.05). Analysis results also revealed statistically significant changes in all measured clinical parameters between baseline and three-month follow-up in both groups (p < 0.05). Upon treatment completion, a decline in the HbA1c level was noted in DM group, but it did not reach statistical significance (p > 0.05). It can be concluded that DM2 patients benefit from non-surgical periodontal therapy, as indicated by a marked reduction in their salivary 8-OHdG level and a modest improvement in glycemic control. Short-term clinical benefits noted in the DM group were similar to those observed in the non-diabetic periodontal patients.

Lipid Peroxidation Levels in Saliva and Plasma of Patients Suffering from Periodontitis.

Lipid peroxidation (LPO) participates in the development of various diseases, including periodontitis, and malondialdehyde (MDA) is its terminal product. Therefore, in the present study, salivary and plasma MDA levels in 30 periodontitis patients were compared to those in 20 healthy controls, as well as in relation to periodontal therapy in order to assess its effectiveness. Periodontal status was assessed via plaque index, gingival index, papilla bleeding index, probing depth and clinical attachment level, while salivary and plasma MDA levels were determined by the ELISA method. The periodontitis group had a significantly greater salivary (2.99 pmol/µL) and plasma (0.50 pmol/µL) MDA levels relative to the healthy controls (1.33 pmol/µL and 0.40 pmol/µL, respectively). Three months after the periodontal therapy completion, although salivary MDA levels were significantly lower than those measured at the baseline (p < 0.001), the reduction in plasma MDA was not statistically significant (p > 0.05). These findings indicate that, while inflammatory processes in periodontium may increase local and systemic lipid peroxidation, periodontal therapy can result in a significant decrease in salivary, but not plasma, MDA levels.

Ralstonia pickettii bacteremia in a cardiac surgery patient in Belgrade, Serbia.

Ralstonia pickettii is an opportunistic bacterium found in the water environment with an increasing incidence as a nosocomial pathogen. The objectives of this study were to describe R. pickettii bacteremia in a cardiac surgery patient and to evaluate its ability to grow in a saline solution and to form biofilm. The patient in this study underwent mitral and aortic valve replacement surgery with two aortocoronary bypasses. She developed signs of respiratory and renal failure, therefore hemodialysis was started. After 25 days in an intensive care unit, the patient had recurrent episodes of fever with signs of bacteremia. R. pickettii was identified from blood cultures by MALDI-TOF MS. Antimicrobial susceptibility testing was performed using disc diffusion and broth microdilution methods in accordance with EUCAST methodology and results were interpreted following clinical breakpoints for Pseudomonas spp. The isolate was susceptible to all tested antimicrobial agents except aminoglycosides and colistin. Survival of R. pickettii was analyzed in saline solution with four different starting concentrations at 25 °C and 37 °C for six days. Biofilm capacity was tested using the microtiter plate method. R. pickettii showed substantial growth in saline solution, with starting concentration of 2 CFU ml-1 reaching 107 CFU ml-1 after six days. There was no significant difference between growth at 25 °C and 37 °C. This indicates that storage of contaminated solutions at room temperature can enhance the count of R. pickettii. Our strain did not show the capacity to form biofilm. The patient responded well to adequate treatment with ceftazidime, and after 48 days in ICU she was discharged to convalesce.

Genomic Epidemiology of Carbapenem- and Colistin-Resistant Klebsiella pneumoniae Isolates From Serbia: Predominance of ST101 Strains Carrying a Novel OXA-48 Plasmid.

Klebsiella pneumoniae is a major cause of severe healthcare-associated infections and often shows MDR phenotypes. Carbapenem resistance is frequent, and colistin represents a key molecule to treat infections caused by such isolates. Here we evaluated the antimicrobial resistance (AMR) mechanisms and the genomic epidemiology of clinical K. pneumoniae isolates from Serbia. Consecutive non-replicate K. pneumoniae clinical isolates (n = 2,298) were collected from seven hospitals located in five Serbian cities and tested for carbapenem resistance by disk diffusion. Isolates resistant to at least one carbapenem (n = 426) were further tested for colistin resistance with Etest or Vitek2. Broth microdilution (BMD) was performed to confirm the colistin resistance phenotype, and colistin-resistant isolates (N = 45, 10.6%) were characterized by Vitek2 and whole genome sequencing. Three different clonal groups (CGs) were observed: CG101 (ST101, N = 38), CG258 (ST437, N = 4; ST340, N = 1; ST258, N = 1) and CG17 (ST336, N = 1). mcr genes, encoding for acquired colistin resistance, were not observed, while all the genomes presented mutations previously associated with colistin resistance. In particular, all strains had a mutated MgrB, with MgrBC28S being the prevalent mutation and associated with ST101. Isolates belonging to ST101 harbored the carbapenemase OXA-48, which is generally encoded by an IncL/M plasmid that was no detected in our isolates. MinION sequencing was performed on a representative ST101 strain, and the obtained long reads were assembled together with the Illumina high quality reads to decipher the bla OXA- 48 genetic background. The bla OXA- 48 gene was located in a novel IncFIA-IncR hybrid plasmid, also containing the extended spectrum ß-lactamase-encoding gene bla CTX-M-15 and several other AMR genes. Non-ST101 isolates presented different MgrB alterations (C28S, C28Y, K2∗, K3∗, Q30∗, adenine deletion leading to frameshift and premature termination, IS5-mediated inactivation) and expressed different carbapenemases: OXA-48 (ST437 and ST336), NDM-1 (ST437 and ST340) and KPC-2 (ST258). Our study reports the clonal expansion of the newly emerging ST101 clone in Serbia. This high-risk clone appears adept at acquiring resistance, and efforts should be made to contain the spread of such clone.

Relation of Steatosis to Neurocognitive Function in People Living with HIV.

BACKGROUND: In HIV negative population metabolic syndrome and steatosis are related to poorer neurocognitive (NC) performance. We investigated if similar relation exists in people living with HIV (PLWH). METHODS: We included male PLWH aged 20-65, with undetectable viral load for at least 6 months. Data on levels of education, anthropometric measurements, CD4 levels, ART, markers of metabolic syndrome, smoking and concurrent treatment were collected from database. Concentrations of TNF-α and IL-6 were measured. An ultrasound was used to establish the presence of steatosis, visceral fat thickness and carotid intima media thickness. An extensive NC assessment was done by an experienced neuropsychologist. Cognitive domains were defined as executive functions, divergent reasoning, visuo-constructional abilities, delayed recall and working memory and learning and were measured using a battery of 12 tests. RESULTS: 88 PLWH were included (mean age 39,9 years), 51% on PIs, 46% on NNRTI; 20,4% had metabolic syndrome, 42% patients had steatosis. Weak but statistically significant negative correlations were found between the presence of metabolic syndrome, steatosis and VFT and cognitive domains (divergent reasoning, delayed recall and working memory). Poorer perfomrance in the domains of divergent reasoning and in the working memory were found in participants with steatosis (p=0,048 and 0,033 respectively). CONCLUSION: Although the sample size was relatively small, our results show consistent correlations between the observed neurocognitive variables and metabolic parameters. As central obesity is one of the contributors to NCI, it would be one of the modifiable factors to prevent further neurocognitive decline.

Antimicrobial Susceptibility and Molecular Characterization of Carbapenemase-Producing Enterobacter spp. Community Isolates in Belgrade, Serbia.

Antimicrobial resistance represents the emerging problem of modern medicine. Despite the fact that Enterobacter spp. is one of the most resistant pathogens, there has been a paucity of data on molecular epidemiology and antimicrobial susceptibility of community isolates in European countries as well as in Serbia. This study was conducted in 2016 and 2017 with the aim to investigate the prevalence of carbapenem-resistant Enterobacter spp. community isolates, molecular determinants of carbapenem resistance, and their genetic relatedness. Seventeen (1.6%) of 1,040 isolates that were positive for carbapenemase screening in accordance with European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations were included in the study. Minimum inhibitory concentrations for selected antimicrobials were determined by broth microdilution and by disk diffusion for chloramphenicol. Multiplex polymerase chain reactions (PCRs) for blaKPC, blaNDM, blaIMP, blaVIM, and blaOXA-48-like carbapenemase genes were performed. Clonality was assessed by enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis. All isolates were multidrug resistant. The most frequent carbapenemase gene found was blaNDM (70.6%), followed by isolates coharboring blaNDM and blaOXA-48-like genes (23.5%) and a single isolate with the blaOXA-48-like gene (5.9%). ERIC-PCR molecular typing showed six different clusters (A-F) with clonal relatedness among isolates from the same institution and association of clusters E and F with the blaNDM carbapenemase gene. Our results indicate the need for Enterobacter spp. surveillance both in the community and hospitals to prevent spreading of multiresistant clones.

THE INFLUENCE OF PERIODONTAL DISEASE TREATMENT ON 8-HYDROXY-DEOXYGUANOSINE CONCENTRATIONS IN SALIVA AND PLASMA OF CHRONIC PERIODONTITIS PATIENTS.

The 8-hydroxy-deoxyguanosine (8-OHdG) is one of the customary products of oxidized DNA. The purpose of this study was to compare salivary and plasma 8-OHdG concentrations in a group of chronic periodontitis patients to those measured in a group of patients with healthy periodontium, as well as to determine the impact of periodontal therapy on 8-OHdG concentrations in saliva and plasma in chronic periodontitis patients. The study sample comprised of 24 patients with chronic periodontitis and 16 periodontally healthy individuals. Plaque index, gingival index, papilla bleeding index, probing depth and clinical attachment level were indices used to determine patient periodontal status. Salivary and plasma 8-OHdG concentrations were determined by ELISA method. The salivary 8-OHdG concentration was statistically significantly higher in the group of periodontitis patients compared to periodontally healthy subjects. After initial periodontal therapy, the 8-OHdG concentration in saliva was significantly reduced in the periodontitis group (p=0.021). Differences in plasma 8-OHdG concentrations between the two groups did not reach statistical significance and no significant changes were noted in the periodontitis group following initial periodontal therapy. A higher salivary 8-OHdG concentration reflects increased oxidative stress caused by periodontal disease. Initial periodontal therapy may be helpful in reducing salivary 8-OHdG concentrations in chronic periodontitis patients.