Neutralization of Wild-Type and Alpha SARS-CoV-2 Variant by CoronaVac® Vaccine and Natural Infection- Induced Antibodies

One of the immune responses desired to be achieved by SARS-CoV-2 vaccination is to create neutralizing antibodies (nAbs), thus preventing the development and spread of infection. The aim of this study was to investigate the seropositivity rate, anti-spike antibody levels, and neutralizing capacity of these antibodies against wild type (WT) and alpha variants in serum samples of individuals who had been naturally infected or vaccinated with CoronaVac®. Total anti-spike antibody levels were determined in all samples. Neutralization assays were performed by the reduction of the cytopathic effect in Vero-E6 cells with infectious WT and alpha SARS-CoV-2 variants. Although both naturally infected and vaccinated individuals were all seropositive for antispike antibodies, 84.8% of the vaccinated group, and 89.3% of the naturally infected group had detectable nAbs. The nAbs titers were significantly higher in the naturally infected group for both WT and alfa variant of the virus as compared to the vaccinated individuals. In this study, it was observed that all individuals became seropositive six weeks after exposure to the vaccine or the virus. Moreover, naturally infected individuals had higher levels of nAbs than those vaccinated. The presence of nAbs against the alpha variant in both naturally infected and vaccinated individuals suggests that these antibodies may also be protective against infections, which may be caused by other variants, such as delta and omicron.

Sociodemographic characteristics and clinical risk factors of Helicobacter pylori infection and antibiotic resistance in the Eastern Black Sea region of Turkey

BACKGROUND/AIMS

The aim of this study was to assess the clinical and sociodemographic risk factors of Helicobacter pylori infection and antibiotic resistance in the eastern Black Sea region of Turkey.

MATERIALS AND METHODS

In total, 344 patients with dyspeptic symptoms who completed an extended questionnaire were enrolled in the study. Diagnosis of H. pylori infection was made by rapid urease test, histopathological investigation, and culture. Susceptibility of H. pylori strains was assessed by agar dilution (amoxicillin, tetracycline, metronidazole, levofloxacin) and E-test (clarithromycin) methods.

RESULTS

The H. pylori positivity rate was 40.4% (139/344). Logistic regression analysis indicated that age and the presence of duodenal ulcer were independent risk factors associated with H. pylori positivity (odds ratio (OR): 0.96, 95% CI: 0.93-0.99, p=0.013; OR: 5.42, 95% CI: 1.96-14.98, p=0.001, respectively). Of 104 H. pylori-positive cultures, 43 strains (41%) were susceptible to all antibiotics, whereas 61 (59%) were resistant to at least one antibiotic. H. pylori resistance rates were 34% for levofloxacin, 31.1% for metronidazole, 28.2% for clarithromycin, 2.9% for amoxicillin, and 1% for tetracycline. Logistic regression analysis indicated that previous use of clarithromycin was the only independent risk factor for H. pylori resistance (OR: 6.25, 95% CI: 1.59-24.52, p=0.009).

CONCLUSION

An understanding of the risk factors for H. pylori positivity and antibiotic resistance in an extended anamnesis may affect treatment choice and facilitate H. pylori eradication. In regions where antibiotic resistance rates are elevated, performing antibiotic susceptibility tests may lead to effective eradication treatment.

Prevalence and characteristics of Hymenoptera venom allergy in urban school children aged 6 to 18 years living in Trabzon

Background/aim

Hymenoptera venom allergy is one of the leading causes of systemic allergic reactions in both adults and children. The present study was conducted to evaluate the prevalence and characteristics of Hymenoptera venom allergy in urban school children aged 6 to 18 years living in Trabzon.

Materials and methods

In this cross-sectional, two-level survey study, children were recruited using random sampling of public primary and secondary schools. Firstly, parents were asked about their child’s age and sex and whether their child had ever been stung by any kind of bee. When they responded “yes” to the last question, they attended a face-to-face interview at the outpatient clinic for the second part of the survey, which included information about history of insect stings and the presence of atopic diseases.

Results

Of 17,000 children, 7904 (46.5%; 3718 males, 47.0%) returned the first-level questionnaire. A total of 4312 (54.5%) were stung at least once in their lifetime. Males had a significantly higher risk of being stung (59.4%, odds ratio: 1.44, 95% confidence interval: 1.32–1.58, p < 0.0001). The second-level questionnaire was completed for 545 (12.6%) of the children. Of 950 stings reported in 545 children, 5.2% were large local reactions (LLRs), 1.9% were generalized cutaneous reactions (GCRs), and 1.3% were systemic reactions (SRs). The stinging insect was Apis mellifera and Vespula in 66.2% and 33.8% of stings, respectively (p < 0.001).

Conclusion

Hymenoptera stings are common in urban school children living in Trabzon. The most common type of allergic reaction is LLR and the most reported stinging insect is Apis mellifera.

[Seroprevalence of Toxoplasmosis among 20 Years and Older Individuals in Trabzon, Turkey]

Introduction

Materials and Methods

Result

Conclusions

Identification and antifungal susceptibility of Saprochaete clavata from invasive infections in Turkey

Saprochaete clavata is an emerging opportunistic pathogen, that causes life-threatening infections, but there are limited evidence and information about the evaluation of in vitro antifungal susceptibility test results. The aim of this study was to determine S. clavata isolates from clinical specimens and to investigate their in vitro antifungal susceptibility. S. clavata was identified by API ID20C AUX (BioMérieux, Brussels, Belgium), MALDI TOF (Bruker Daltonik, Germany), and ITS gene region sequencing. In vitro susceptibility tests were performed using Sensititre YeastOne (TREK Diagnostic System, East Grinstead, UK). During the study period, 4,736 fungi were isolated from various clinical samples and, S. clavata was identified in eight patients with underlying diseases namely, pancreatic neoplasma, acute myeloid leukaemie, follicular lymphoma, cholelithiasis. Anidulafungin and micafungin minimum inhibitory concentration values were 1-2 and 1-4 mg/L, respectively, while those of the azole group antifungals were much lower. This is the first study in Turkey reporting isolation, identification and antifungal susceptibilities of S. clavata from clinical specimens. Higher MIC values seen in some isolates suggest that continuous monitoring of sensitivity rates and observation of regional differences will thus be useful guides in determining infection control and antifungal use policies.

[Investigation of Plasmid Mediated mcr Colistin Resistance Gene in Clinical Enterobacterales Isolates]

Carbapenems are used in the treatment of infections caused by multidrug-resistant bacteria and colistin (polymyxin E) is used as the last choice of antimicrobial agent in those resistant to carbapenems. The worldwide and increased use of colistin, which causes cell death by disrupting the permeability of the cytoplasmic membrane of gram-negative bacteria, raised the problem of resistance. The transferable colistin resistance enzyme mcr, is a phosphoethanolamine transferase that adds phosphoethanolamine to lipid A and modifies lipopolysaccharides, leading to polymyxin resistance. The aim of this study was to investigate some of the most prevalent plasmid mediated colistin and carbapenemase resistance genes in colistin resistant Enterobacterales isolates. Enterobacterales isolates which were isolated in the samples of patients treated in the clinical units between October 2016 and September 2018 in the Karadeniz Technical University Faculty of Medicine Farabi Hospital Medical Microbiology Laboratory were included in the study. In addition to conventional methods, isolates were identified to the species level by MALDI-TOF MS (Bruker Daltonics, Germany). The antibiotic susceptibilities of Enterobacterales isolates were studied by an automated microbiology system (Phoenix, Becton Dickinson, USA) and evaluated according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. In isolates that are resistant to colistin, and the isolates that are found to be sensitive but should be included in the patient report of the colistin susceptibility test, colistin susceptibility tests were repeated with liquid microdilution method in accordance with EUCAST standards. The presence of extended spectrum beta-lactamase (ESBL), AmpC beta-lactamase and carbapenemase were determined by phenotypic methods according to EUCAST recommendations in colistin resistant Enterobacterales isolates. Furthermore, resistance genes of mcr-1-5, blaOXA-48, blaKPC, blaNDM, blaVIM, blaIMP were detected by polymerase chain reaction (PCR) method, followed by nucleotide sequence analysis of the amplified products. In our study, 14657 Enterobacterales isolates belonging to 7535 patients treated in different clinical units were examined retrospectively. Escherichia coli 61.2% (n= 8968), Klebsiella pneumoniae 22.7% (n= 3334) and Enterobacter cloacae 6.9% (n= 1005) were the most prevalent isolates. Carbapenem resistance was detected in 894 isolates, and 5.8% (n= 412) of 7135 isolates isolated between October 2016 and September 2017; 6.4% (n= 482) of 7522 isolates between October 2017 and September 2018 were found to be resistant. Considering all isolates, colistin resistant isolates were 65 (0.9%) between October 2016 and September 2017 and 97 (1.3%) between October 2017 and September 2018. By including only the first isolates in the study for the same agent growths in different samples of the same patient, 46 colistin resistant isolates were selected. Six isolates which could not be cultivated from stock cultures were excluded from the study material. Thirteen (32.5%) of the 40 colistin resistant Enterobacterales isolates were isolated in 2017 and 27 (67.5%) were isolated in 2018. ESBL was detected in 22, AmpC beta-lactamase was detected in 6, carbapenem resistance was detected in 15 of them by phenotypic methods. As a result of PCR analysis, mcr-1 gene detected in 2 isolates, blaOXA-48 in 2 isolates, blaVIM in 1 isolate, blaKPC and blaOXA-48 in 1 isolate, blaNDM and blaOXA-48 in 5 isolates. These results were confirmed by sequencing of the PCR products. The mcr-1 genes were found in E.coli isolates grown in urine culture samples of 2 women over 65 years of age treated in our hospital. Among the antibiotics tested, only ampicillin resistance was observed in 1 of the patients, whereas ampicillin, amoxicillin-clavulanate and ciprofloxacin resistance were detected in the other. In conclusion, as far as we can reach in the literature our publication is the first study showing the presence of mcr-1 gene in clinical samples in our country and confirmed by DNA sequence analysis. The detection of mcr gene in isolates without multidrug resistance showed once again the importance of colistin susceptibility testing in the laboratories. In addition, the presence of isolates containing more than one resistance genes in our study, suggests that the spread of carbapenem and colistin resistance may be faster than expected.

[Comparison of mRNA Levels of Stimulator of Interferon Genes (STING) in Individuals with Natural Immunity to Hepatitis B Virus (HBV), and in those with Chronic Hepatitis B Infection and without HBV]

It has been estimated that currently 350-400 million people have been chronically infected with the hepatitis B virus (HBV) worldwide and approximately one million people die each year due to HBV related diseases. It has been suggested that the viral and host factors, especially the host immune system, may play a role in the chronicity of the HBV infection. Stimulator of interferon genes (STING) is one of the members of the pattern recognition receptor (PRR) that detects the presence of DNA in a human cell, activate synthesis of various cytokines and this protein is thought to be an important member of the immune system against HBV infection. Based on the assumption that there may be a relationship between the differences of STING expression in individuals and HBV chronicity, the aim of this study was to investigate STING gene expression levels in individuals naturally immunized against HBV, in chronic hepatitis B infected patients and in normal individuals who have not been exposed to HBV. A total of 90 volunteers have been included in the study from the age range of 18 to 65, in which the first group consists of 30 individuals naturally immunized against HBV, the second group consists of 30 chronically hepatitis B infected patients while the third group consists of 30 healthy population members who have not been exposed to HBV. Whole blood samples were taken from each participant and peripheral blood mononuclear cells (PBMC) were isolated afterwards. Total RNA was isolated from PBMC. After the synthesis of cDNA from the total RNA, STING gene expression levels were determined by real time polymerase chain reaction (Rt-PCR) method. Normalization was performed by applying the 2-ΔΔCT formula after Rt-PCR procedure. STING expression level of the naturally immunized group was calculated as 0.084 ± 0.026 on average, average STING expression level of healthy population group was 0.082 ± 0.032 and STING expression level of chronically infected patients group was 0.075 ± 0.022 on average. There was no statistically significant difference between the groups (p> 0.05). To our knowledge, this is the first study investigating the role of STING expression in the chronicity of HBV. Although there was no statistically significant difference between the groups, the data that showed STING expression levels in naturally immunized individuals were approximately 10% higher than those in chronic hepatitis B patients and was considered as an important finding.

Hydroxytyrosol: The Phytochemical Responsible for Bioactivity of Traditionally used Olive Pits

The fruits of Olea europaea L. is widely consumed as food, and olive pits are utilized in folk medicine to relieve gastric disturbances. In the present study, the possible anti-inflammatory, analgesic and antioxidant activities of aqueous extracts of black (BP) and green olive (GP) pit prepared at gastric fed state pH were evaluated in vitro. Moreover, the bioactive compound, hydroxytyrosol (HT), was isolated from the extracts for the first time. According to results, GP extract (62.5 to 1000 μg/mL) showed significant anti-inflammatory activity in a dose-dependent manner and HT displayed significant nitrite inhibition at 100 μM with slight analgesic activity. Extracts and HT showed a significant antioxidant activity according to Total Antioxidant Capacity (TOAC), cupric ion reducing antioxidant capacity (CUPRAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. As a conclusion, a proper formulation containing HT might be a potential remedy to relieve gastric disturbances and olive pits, can be utilized as a valuable industrial tool for the low-cost production of HT.

How to cite this article: Reis R, Sipahi H, Zeybekoglu G, Celik N, Kirmizibekmez H, Kaklikkaya N, Aydin A. Hydroxytyrosol: The Factor Responsible for Bioactivity of Traditionally used Olive Pits. Euroasian J Hepatogastroenterol, 2018;8(2):126-132.

Characteristics of beef allergy in schoolchildren in Turkey

BACKGROUND

The prevalence of immunoglobulin E (IgE) mediated beef allergy in childhood is unknown. We investigated the prevalence and characteristics of IgE-mediated beef allergy in urban schoolchildren.

METHODS

This cross-sectional study recruited 6000 randomly selected urban schoolchildren ages 6-17 years from the city center of Giresun in the eastern Black Sea region of Turkey during 2013. Children with suspected IgE-mediated beef allergy, determined by a self-administered questionnaire, after providing written consent, were skin-prick tested with commercial beef and cow's milk solutions and prick-prick tested with raw, boiled, and fried beef. Levels of serum-specific IgE to beef specific IgE and serum-specific IgE to cow's milk were determined by using fluorescent enzyme immunoassay. All children with suspected beef allergy were invited for a double-blind, placebo controlled food challenge (DBPCFC) to determine the prevalence of IgE-mediated beef allergy.

RESULTS

The response rate to the questionnaire was 82.2%. The estimated prevalence of parental-reported IgE-mediated beef allergy was 2.6%. The prevalence of IgE-mediated beef allergy confirmed by DBPCFC was 0.30% (95% confidence interval, 0.18-0.5%). Positive challenge responses were observed in 70.6% (p = 0.027), 76.9% (p = 0.027), and 73.3% (p = 0.028) of the children with a positive family history of beef allergy, positive skin test results, and positive beef specific IgE values, respectively. A beef specific IgE value of >5 kUA/L alone or a combination of a positive family history of beef allergy, positive skin test results, and beef specific IgE values of >3 kUA/L yielded a positive response to DBPCFC.

CONCLUSION

The presence of a family history of beef allergy, beef specific IgE value, and skin test result positivity are independently associated with positive DBPCFC results, and combined evaluation of these three parameters increased the positive predictive power of the tests.

Effects of long-term synbiotic supplementation in addition to lifestyle changes in children with obesity-related non-alcoholic fatty liver disease

BACKGROUND/AIMS

We aimed to analyze the efficiency of a novel treatment approach, long-term synbiotic supplementation, in addition to lifestyle changes in children with non-alcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

The study included children with NAFLD (n=28) and a healthy control group (n=30). Children with NAFLD were given 1 capsule/day of synbiotics. Anthropometric parameters; biochemical analysis, including ethanol, tumor necrosis factor-α (TNF-α), total oxidant status (TOS) and anti-oxidant status (TAS), zonulin, and fecal calprotectin; and ultrasonographic examination were performed at baseline and 4 months later.

RESULTS

The grade of fatty liver was decreased (≥1 grade) in 19 of the 28 patients (67.8%) after synbiotic supplementation. Total cholesterol, low-density lipoprotein (LDL) levels, TNF-α, C-reactive protein (CRP), and ethanol were significantly decreased, and TAS levels were significantly increased at the end of treatment (p<0.05 for all). We found that the median decrease in CRP (-0.16 vs. -0.03 mg/dL, p=0.003) and LDL levels (-17 vs. -3 mg/dL, p=0.019) were higher in patients who responded to the supplementation.

CONCLUSION

Synbiotic supplementation in addition to lifestyle changes is effective in children with NAFLD.

Determination of Seroprevalence of Borrelia burgdorferi IgG in Adult Population Living in Trabzon

BACKGROUND

Lyme borreliosis is a tick-borne, multi-systemic infectious disease that is thought to be wide spread in Turkey even though studies on its seroprevalence are limited.

AIMS

To determine the seroprevalence of Lyme borreliosis in part of north-eastern Tur-key (in the city of Trabzon), and to identify possible relationships between seropositivity and various factors such as location, gender, age group, occupation, income, and educational level.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

A total of 884 blood samples collected from provincial and district health centers serving a population of about 800,000 were included in this study. ELISA was used to determine the anti-Borrelia IgG antibody levels in the samples. Samples that yielded positive results by ELISA were further subjected to western blot (WB).

RESULTS

IgG antibodies were found in 128 samples (14.5%). Statistical analysis revealed significant differences between age groups and educational levels in terms of the incidence of seropositivity, whereas location, gender, occupational group and income level had no effect (p<0.001, p<0.001, p=0.948, p=0.645, p=0.131, p=0.080 respectively).

CONCLUSIONS

The risk of contracting Lyme borreliosis in Trabzon is high, and necessary measures need to be taken to avoid the spread of disease.

Hepcidin expression in psoriasis patients

Background:

Iron is an essential nutrient for mammals. Accelerated loss of nutrients through hyperproliferation and desquamation from the skin in psoriasis is known. Hepcidin is an important and recently discovered regulator of iron homeostasis.

Aims and Objectives:

The present study was undertaken to investigate the hepcidin expression in psoriasis patients.

Materials and Methods:

We examined peripheral blood cell counts, serum Fe, ferritin, interleukin-6 (IL-6) and hepcidin levels using respectively automated hematology analyzer, Iron assay on the AEROSET system, chemiluminescent microparticle immunoassay with automated analyzer, and enzyme-linked immunosorbent assay.

Results:

The independent comparison of Fe, ferritin, IL-6 and hepcidin levels in psoriasis patients and control group (healthy volunteers) revealed lower Fe and higher IL-6, hepcidin levels in psoriasis patients. No significant difference was seen in the ferritin level between the psoriasis and the control group.

Conclusions:

We think that studies on hepcidin expression in psoriatic plaques will contribute to our understanding the role of iron and hepcidin in the pathogenesis of psoriasis.

[Determination of hepatitis C virus genotypes among hepatitis C patients in Eastern Black Sea Region, Turkey]

Hepatitis C virus (HCV), the major cause of transfusion-associated hepatitis, is an important public health problem in the world as well as in Turkey. HCV is grouped as six distinct genotypes and a large number of closely-related subtypes. Genotyping of HCV is an important tool for providing epidemiological data, prediction of prognosis, and optimization of antiviral therapy. This study was carried out to determine the distribution of HCV genotypes in hepatitis C patients residing in different provinces of the Eastern Black Sea Region, Turkey. A total of 304 HCV-RNA positive cases (151 male, 153 female; age range: 11-93 years, mean age: 55.2 ± 13.3 years) who were admitted to the Molecular Microbiology Unit of Department of Medical Microbiology, Karadeniz Technical University Faculty of Medicine, between January 2009 to December 2012, were included in the study. HCV genotypes were detected in plasma samples of the patients by using commercial assays [INNO-LiPA HCV II (Innogenetics, Belgium) or Abbott RealTime HCV Genotype II (Abbott Molecular Inc, USA)]. Due to the ambiguous genotyping results in some samples with these methods, an in-house multiplex polymerase chain reaction (PCR) assay with genotype-specific primers was also used in the study. Similar to the previous reports from Turkey, our results showed that four HCV genotypes (1, 2, 3, and 4) prevailed in the Eastern Black Sea Region and the predominant genotype and subtype were genotype 1 (92.8%) and 1b (87.5%), respectively. Distribution of genotypes were observed to vary according to the province. Prevalences of subtype 1a, genotype 2, 3, and 4 were noted as 5.3%, 1.6%, 4.9%, and 0.7%, respectively. Furthermore, the samples from Giresun, Gumushane and Bayburt provinces, which are relatively less immigrated, had higher genotype 1, and the prevalence rates in the region was affected by the presence of non-citizen residents. This study is the first report on distribution of HCV genotypes in chronic hepatitis C patients living in the provinces of Eastern Black Sea Region. Moreover, genotype-specific multiplex PCR assay could be useful in resolving certain methodological problems such as "ghost bands" encountered in line probe assay (LiPA) and multiple genotypes (including genotype 4) observed in real-time PCR during the characterization of HCV genotypes seen in Turkey.

Accuracy of HLA-DQ genotyping in combination with IgA anti-tissue transglutaminase serology and a "scoring system" for the diagnosis of celiac disease in Turkish children

The aim of the study was to analyze the accuracy of (i) HLA-DQ typing and anti-tissue transglutaminase antibodies immunoglobulin A (tTG-IgA) serology and (ii) a "simple scoring system" (SSS) for the diagnosis of celiac disease (CD). The study included 91 patients with positive tTG-IgA, who had been tested for HLA-DQ. Patients were divided into 3 groups: typical CD, atypical CD, and non-CD. The sensitivity, specificity, positive (PPV) and negative predictive value (NPV), positive (PLR) and negative likelihood ratio (NLR) and accuracy of the test combining genotyping and tTG-IgA positivity and the simple scoring system for the diagnosis of CD were evaluated. The combination of genotyping and strong tTG-IgA positivity had a sensitivity of 93.5%, specificity of 61.5%, PPV of 93.5%, NPV of 61.5%, PLR of 2.4, NLR of 0.1 and accuracy of 89% for "CD." SSS had a higher specificity (84.6%), higher PPV (97.3%), higher NPV (68.7%), higher PLR and higher accuracy (92.3%). The combination of genotyping and strong tTG-IgA positivity missed two patients with typical CD (4%) and three patients with atypical CD (10.7%). Two cases with malabsorptive symptoms (33.3%) and three patients without malabsorptive symptoms (42.8%) would have been misdiagnosed as CD if these tests were used. Intestinal biopsy is still mandatory for diagnosis of CD in Turkish children.

[Resistance rates of Mycobacterium tuberculosis complex strains isolated from clinical specimens]

The aim of this study was to investigate isoniazid, rifampicin, streptomycin and ethambutol resistance rates of Mycobacterium tuberculosis complex strains isolated from clinical specimens in the Mycobacteriology Laboratories of Karadeniz Technical University Hospital between January 2005-March 2010. A total of 212 M.tuberculosis complex strains, 152 (71.7%) of which were isolated from respiratory specimens and 60 (28.3%) from non-respiratory system specimens, were included to the study. M.tuberculosis complex strains were determined by polymerase chain reaction using primers specific for the IS6110 gene region. Single isolate of each patient were enrolled in the study. Antituberculosis drug susceptibility testing was performed by BACTEC MGIT 960 (Becton Dickinson, USA). Of the 212 isolates, 157 (74.05%) were susceptible to all of the four antimycobacterial agents while 55 (25.9%) were found resistant to one or more of the drugs. The monodrug resistance rates were found as 6.1% for isoniazid, 0.5% for rifampicin, 5.2% for streptomycin, and 2.4% for ethambutol. The number of multidrug resistant isolates characterized with resistance to isoniazid and rifampicin were 10 (4.8%). Our findings indicated that the rates of mono and multidrug resistant M.tuberculosis complex strains were significantly lower than the rates previously reported from our region and similar to the average country-base resistance rates reported by the Ministry of Health. Continuous monitoring of M.tuberculosis antimicrobial resistance at regional level would greatly aid to the success of the tuberculosis surveillance program in Turkey.