The comparison of SARS-CoV-2 antibody levels in medical personnel induced by different types of vaccines compared to the natural infection.

INTRODUCTION: During the last two and a half years, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread around the world. Most of the SARS-CoV-2 vaccines are designed to produce anti-SARS-CoV-2 immunoglobulin G (IgG) against the viral S-glycoprotein. The aim of this study was to measure the anti-S antibody titres among the medical personnel who had been fully vaccinated with different types of vaccines, and to compare them with those who were COVID-19 convalescents. MATERIAL AND METHODS: In this study serum was collected from 261 healthcare workers, of whom 227 were vaccinated, while 34 were recovered participants who were not immunised. Serum samples were collected 21 days after the first dose and 60 and 180 days after the second dose of the vaccines and tested with a commercial ELISA kit. RESULTS: The highest antibody level (12 AU/ml) was measured in the Pfizer-BioNTech group, followed by Sinopharm (9.3 AU/ml), Sputnik V (5.9 AU/ml), Sinovac (4.6 AU/ml) and Oxford/Astra- Zeneca vaccine (2.5 AU/ml) 60 days after the second dose of the vaccines (90 days after the first dose). The seropositivity rate for mRNA vaccine was 88.5%, for vector vaccines 86.2% and for inactivated vaccines 71.4%. When comparing these antibody levels with COVID-19 convalescents, higher antibody titres were found in vaccinated participants (5.76 AU/ml vs 7.06 AU/ml), but the difference was not significant (p = 0.08). CONCLUSIONS: Individuals vaccinated with mRNA and vector vaccines had a higher seroconversion rate compared to the group vaccinated with inactivated vaccines, or convalescents.

Seroprevalence of SARS-CoV-2 antibodies among primary healthcare workers in the Republic of Srpska, Bosnia & Herzegovina: A cross-sectional study.

Healthcare workers (HCW) in primary healthcare centres in the Republic of Srpska, Bosnia and Herzegovina, are on the first combat line with COVID-19. This study aimed to assess the seroprevalence of SARS-CoV-2 among HCW at the primary healthcare centres and to analyse the risk exposure to COVID-19, clinical signs and vaccination status. A cross-sectional study was conducted among HCW at the selected primary healthcare centres between 19 March and 30 April 2021. Antibodies against the SARS-CoV-2 virus were detected by enzyme-linked immunosorbent assay (ELISA). A total of 1,023 HCW (mean age 45 years; 71% female) were included in the study. The anti-SARS-CoV-2 antibodies were detected in 69.5% of all participants. There was a significant difference in seropositivity among primary healthcare centres from different geographical regions. As many as 432 (42%) of all participants had confirmed COVID-19 symptoms before the study and, 84.8% of them were seropositive. This study showed that 702 primary HCW were vaccinated with any of these vaccines: Sputnik V, Sinopharm, Pfizer/Biontech. High titre of SARS-CoV-2 antibodies was found amongst those who received one (92.6%) or both (97.2%) doses of vaccines. In this study, we report high prevalence of SARS-CoV-2 antibody among HCW in primary healthcare in the Republic of Srpska, Bosnia and Herzegovina during the third pandemic wave.

Seroprevalence of SARS-CoV-2 antibodies and knowledge, attitude and practice toward COVID-19 in the Republic of Srpska-Bosnia & Herzegovina: A population-based study.

The aim of the study was to assess the seroprevalence of SARS-CoV-2 in the Republic of Srpska, Bosnia and Herzegovina, and to analyse the knowledge, attitudes and practices of the population toward COVID-19. This population-based study was conducted in a group of 1,855 randomly selected individuals from all municipalities from 1 December 2020 to 15 January 2021. All individuals were asked to sign a consent form and to fill in a questionnaire, following which a blood samples were collected. Total anti-SARS-CoV-2 antibodies were determined in serum specimens using the total Ab ELISA assay. The overall seroprevalence rate was 40.3%. Subjects aged <65 years were 2.06 times more likely to be seropositive than those aged ≥65, and 30% of seropositive individuals presented no COVID-19 symptoms. The household members of seropositive individuals were 2.24 times more likely to develop COVID-19 symptoms than the household members of seronegative individuals. More than 95% of respondents believe that preventive measures are very important to control the infection transmission. Majority of respondents wear the masks properly, maintain the required physical distance whenever possible and wash hands with soap. Nearly 50% of individuals were of the opinion that the vaccine could prevent the infection. This study showed that an overall SARS-CoV-2 seropositivity rate by the middle of January 2021 was very high. Attitudes and practices regarding the COVID-19 indicate that additional efforts should be taken in order to improve the health education with a focus on preventive measures and vaccination.

Pomegranate peel extract polyphenols attenuate the SARS-CoV-2 S-glycoprotein binding ability to ACE2 Receptor: In silico and in vitro studies.

The novel coronavirus disease (Covid-19) has become a major health threat globally. The interaction of SARS-CoV-2 spike (S) glycoprotein receptor-binding domain (RBD) with ACE2 receptor on host cells was recognized as the first step of virus infection and therefore as one of the primary targets for novel therapeutics. Pomegranate extracts are rich sources of bioactive polyphenols that were already recognized for their beneficial health effects. In this study, both in silico and in vitro methods were employed for evaluation of pomegranate peel extract (PoPEx), their major polyphenols, as well as their major metabolite urolithin A, to attenuate the contact of S-glycoprotein RBD and ACE2. Our results showed that PoPEx, punicalin, punicalagin and urolithin A exerted significant potential to block the S-glycoprotein-ACE2 contact. These in vitro results strongly confirm the in silico predictions and provide a valuable insight in the potential of pomegranate polyphenols for application in SARS-CoV-2 infection.

Type I, II, and III Interferons: Regulating Immunity to Mycobacterium tuberculosis Infection.

Interferons (IFNs) are cytokines released by host cells in response to the presence of pathogens or tumor cells. The aim of this review was to present the previously known and new findings about the role of interferons type I and II, and recently discovered type III in Mycobacterium tuberculosis (M. tuberculosis) infection control. Infection of various cell types with M. tuberculosis induce both IFN-α and IFN-ß synthesis. The majority of the studies support the findings that IFN type I actually promotes infection with M. tuberculosis. It has been well establish that IFN-γ has protective function against M. tuberculosis and the other mycobacteria and that the primary source of this cytokine are CD4(+) and CD8(+) T cells. Recently, it has been shown that also the innate lymphocytes, γδ T cells, natural killer (NK) T cells, and NK cells can also be the source of IFN-γ in response to mycobacterial infection. Several studies have shown that CD4(+) T cells protect mice against M. tuberculosis independently of IFN-γ. The balance between IFN-γ and different cytokines such as IL-10 and other Th2 cell cytokines is likely to influence disease outcome. Type I IFN appears to be detrimental through at least three separate, but overlapping, type I IFN-mediated mechanisms: induction of excessive apoptosis, specific suppression of Th1 and IFN-γ responses, and dampening of the immune response by strong IL-10 induction. Recently it has been found that M. tuberculosis infection in A549 lung epithelial cells stimulate up-regulation of IFN-λ genes in vitro. IFN-λs also have a role in modulation of Th1/Th2 response. IFN-λs are not essential for M. tuberculosis infection control, but can give some contribution in immune response to this pathogen.

In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens.

Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract.

[Production of pili, hemolysin and siderophores in the urinary isolates of Escherichia coli].

INTRODUCTION: Escherichia coli (E. coli) are the most frequent cause of the urinary tract infections. Uropathogenic E. coli (UPEC) produce virulence factors which enable them to survive in the urinary tract and cause an infection. OBJECTIVE: The objective of this study was to determine phenotype characterization of E. coli isolated from outpatients' urine in the region of Banja Luka over three-year period. In line with the objective, the following research tasks were set up: determining the production of type 1 fimbriae, P-pili, alpha-hemolysin and siderophores. METHODS: A total of 417 urinary isolates and 100 control intestinal isolates were screened for virulence factors. Production of adhesions was confirmed by haemagglutination test. Plate haemolysis test was done for the detection of alpha-hemolysin, and siderophores production assay was carried out by using the method named chrome azurol sulfonate agar diffusion assay. RESULTS: In the group of urinary isolates, almost 60% of isolates produced two or three virulence factors; only 3.8% produced none of the virulence factors. In the group of intestinal isolates, even 43% of isolates produced none of the virulence factors while 48% of isolates produced a single virulence factor and 9% produced two virulence factors. CONCLUSION: Urinary isolates E. coli express significantly more P-pili, alpha-hemolysin and siderophore than intestinal isolates (p < 0.001).There was no significant difference in production of type 1 fimbriae among the urinary and intestinal isolates.

Phenolic content, antibacterial and antioxidant activities of Erica herbacea L.

Antibacterial and antioxidant activity, total phenolic and flavonoid concentrations of aqueous, ethanol and ethyl acetate extracts from the leaves and flowers of Erica herbacea L. were studied. In vitro antibacterial activity of the extracts was determined by macrodilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) have been determined. Testing was performed on 30 clinical isolates, including different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris. The values for MIC were in the range from 2.5 mg/mL to 40 mg/mL. The most sensitive bacterial strains were Proteus vulgaris strains. The aqueous extract from E. herbacea was found the most active. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 14.98 and 119.88 mg GA/g. The concentration of flavonoids in extracts was determined using spectrophotometric method with aluminium chloride and obtained results varied from 16.19 to 26.90 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent. The highest capacity to neutralize DPPH radicals was found in the aqueous extract from E. herbacea. The results of the total phenolic content determination of the examined extracts indicate that E. herbacea extracts are a rich source of phenolic compounds and also possess a significant antioxidant activity and moderate antibacterial activity.

[Prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamase producing urinary isolates of Escherichia coli in outpatients].

INTRODUCTION: In Gram-negative bacteria, the production of beta-lactamases is the most important mechanism of resistance to beta-lactam antibiotics. In the Banja Luka region, there were no extensive researches on the prevalence and antimicrobial resistance of the extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) isolates. OBJECTIVE: The aim of the present study was to determine the presence of ESBL producing E. coli isolates as the cause of the urinary tract infections in outpatients, the distribution of these ESBL isolates according to age and gender of patients and their susceptibility to antimicrobials. METHODS: Urine specimens obtained from outpatients were cultured on chromogenic CPS-ID3 media. All plates showing significant (> 10(5) cfu/ml) growth of E. coli in pure culture were further processed. Antimicrobial susceptibility testing was performed on VITEK TWO Compact using AST-GN27 cards for testing Gram negative bacteria and detection of ESBL producers. RESULTS: Out of 2,195 isolates, 177 (8.1%) were ESBL producers. Ninety-two isolates were obtained from female patients (5% of E. coli isolated from women) and 85 isolates from male patients (23% of E. coli isolated from men). High percentage of ESBL isolates was detected in the infant age group under one year (36.7%) and in the age group over 60 years (28.8%). All ESBL isolates were susceptible to imipenem and resistant to ampicillin, piperacillin, cefazolin, cefotaxime, ceftazidime and cefepime. There was a significant resistance to amikacin (79.1%), gentamicin (76.8%), amoxicillin/clavulanate (54.8%) and trimethoprim/sulphamethoxazole (45.8%). Resistance to nutrofurantoin was 13.6%. CONCLUSION: This study has demonstrated the presence of ESBL producing E. coli urinary isolates in outpatients, and their extensive susceptibility to imipenem and nitrofurantoin.