Browsing by Author "Ristanović, Elizabeta (55278691500)"

Background/Aim. Bacillus cereus (B. cereus) usually ingested by food can cause two types of diseases: vomiting due to the presence of emetic toxin and diarrheal syndrome, due to the presence of diarrheal toxins. Systemic manifestations can also occur. The severe forms of disease demand antibiotic treatmant. The aim of this study was to determine the differences in antibiotic susceptibility and β-lactamase activity of B. cereus isolates from stools of humans, food and environment. Methods. Identification of B. cereus was performed with selective medium, classical biochemical test and polymerase chain reaction (PCR) with primers specific for bal gene. Thirty isolates from each group were analysed for antibiotic susceptibility using the disk-diffusion assay. Production of β-lactamase was determined by cefinase test, and double-disc method. Results. All strains identified as B. cereus using classical biochemical test, yielded 533 bp fragment with PCR. Isolates from all the three groups were susceptible to imipenem, vancomycin, and erythromycin. All isolates were susceptible to ciprofloxacin but one from the environment. A statistically significant difference between the groups was confirmed to tetracycline and trimethoprim-sulphamethoxazole sensitivity. A total of 28/30 (93.33%) samples from the foods and 25/30 (83.33%) samples from environment were approved sensitive to tetracycline, while 10/30 (33.33%) isolates from stools were sensitive. Opposite to this result, high susceptibility to trimethoprim-sulphamethoxazole was shown in samples from stools (100%), while isolates from foods (63.33%) and from environment (70%) had low susceptibility. All samples produced β-lactamases. Conclusion. The strains of B. cereus from all the three groups showed high rate of sensitivity to most tested antibiotics, except to tetracycline in samples from human stool and to trimethoprim-sulphamethoxazole in samples from food and environment. The production of β-lactamases was confirmed in all the strains. © 2016, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved.

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Background/Aim. Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) 2019 infection represents a global problem. At this moment, in October 2020, there is no vaccine or efficient treatment for infected patients. Treatment with blood plasma rich with anti-SARS-CoV-2 specific antibodies might be a safe, and effective therapy for COVID-19 patients. Methods. A total of 768 patients were analyzed in this study, whose samples were collected in a time interval from May 1, 2020, till August 15, 2020. Patients were enrolled in the study from COVID-19 hospitals and out-clinics. In-house ELISA tests were developed to measure the concentration of anti-S1S2 spike and anti-nucleoprotein (np) (IgG, IgA, IgM) SARS-CoV-2 antibodies. Blood convalescent plasma was selectively collected from recovered patients according to specific antibodies concentration. Results. The highest concentrations of anti-S1S2 spike or anti-np specific IgG antibodies were detected in patients with the moderate/heavy clinical form of the infection. An extremely high concentration of anti-S1S2 spike IgG and anti-np IgG was demonstrated in 3% and 6% of patients who recovered from severe COVID-19, respectively. Of tested hospitalized patients, 63% and 51% had modest levels of anti-S1S2 spike and anti-np, respectively. After 60 days, in our selected donors, concentrations of antiS1S2 spike IgG and anti-np IgG antibodies increased in 67% and 58% of donors, respectively. Conclusion. In-house developed ELISA tests enable a novel protocol for selecting convalescent blood plasma donors recovered from SARS-CoV-2 infection. © 2022 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Background/Aim: Intravenous drug users (IDUs) are still a high risk-group for cross-reacting blood-borne infections, for vertical pathogen transmission as well as for potentially blood/plasma donation (especially as "paid" donors). The aim of our study was to establish the profile of opiate addict and prevalence of blood-borne pathogens - Hepatitis B virus (HBV), Hepatitis C virus (HCV) and Human Immunodeficiency Virus (HIV) among 99 patients on substitution therapy with methadone and buprenorphine from Šumadia District. Methods: The Treatment Demand Indicator (TDI) of Pompidou-questionnaire was used to assess the history of drug abuse and risk behavior. All blood samples were tested for HBV surface antigen (HBsAg), anti-HCV antibody (anti-HCV) and HIV antigen/antibody (HIV-Ag/Ab) by Enzyme-Linked ImmunoSorbent Assay (ELISA) or Chemiluminescent Immuno-Assay (CIA). Investigations were also performed for HBV, HCV and HIV by molecular testing - Polymerase Chain Reaction (PCR) method. Results: The majority of patients were males (81.8%), median age 32 (19-57) years, lived in a city (99%), unemployed (58.6%), with finished secondary school (67.7%), unsafe injecting practices (34.3%) and never previously tested for HBV (39.4%), HCV (36.4%) nor HIV (28.3%); only 4% of them previously got HBV-vaccine. The complementary testing resulted with following results: HBV ELISA/CIA and PCR negativity for 66 patients and positive results (by ELISA/CIA and PCR) for 19 patients. However, a difference was observed in the ELISA/CIA-negative/PCR-positive result for 12 and ELISA/CIA-positive/PCR-negative for two patients respectively. Further, the negative results for HCV (ELISA/CIA and PCR testing) were found in 15 IDUs and positive results (using both methods) were found in 58 patients. Different results for ELISA/CIA-negative / PCR-positive results were found in 11 IDUs and ELISA/CIA-positive/PCR - negative results were found in 15 patients. All investigated IDUs were negative for HIV (ELISA/CIA and PCR testing) and for pathogens of opportunistic infection (Cryptococcus neoformans; Pneumocystis carinii; PCR testing), as well as for West Nile Virus (PCR testing). Just one IDU was positive for syphilis (ELISA and confirmatory testing). Conclusion: Our study demonstrated that the positivity for HBV and HCV is still very high (33.4% and 84.8%, respectively) in IDUs. Thus, we suggest that drug users have to be periodically screened using a complementary serological/molecular testing - concerning differences/discrepancies in the results obtained using these methods. © 2019 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.