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Öğe Acinetobacter mesopotamicussp. nov., Petroleum-degrading Bacterium, Isolated from Petroleum-Contaminated Soil in Diyarbakir, in the Southeast of Turkey(Springer, 2020) Acer, Omer; Guven, Kemal; Poli, Annarita; Di Donato, Paola; Leone, Luigi; Buono, Lorena; Guven, Reyhan GulA new petroleum-degrading bacterium, designated strain GC2(T), was isolated from Bozkus 1 petroleum station in Diyarbakir, located in the southeast of Turkey. Cells were Gram-negative staining, aerobic, coccoid-rods, non-motile, non-spore-forming. The bacterium was found to degrade 100% ofn-alkanes ranging from C11 to C34 presented in the 1% crude oil after incubation of 7 days. The membrane phospholipids were 1,2 diacylglycero-3-phosphorylethanolamine (PEA), phosphatidylglycerol (PG), dipalmitoyl-sn-glycerol 1- phosphocholine (PC1), 1,2 dipalmitoyl-sn-glycero-3-phosphocholine monohydrate (PC3), cardiolipin also called diphosphatidylglycerol (CL) and l-alpha- phosphatidic acid, dipalmitoyl (AP); predominant respiratory ubiquinone was Q-8 and C16:0, C18:1 omega 9c and C16:1 were the major cellular fatty acids. The 16S rRNA sequence analysis revealed that the strain GC2(T)was a member of genusAcinetobacterand was most closely related toAcinetobacter lwoffiiDSM 2403( T)(99.79%),Acinetobacter pseudolwoffiiANC 5318( T)(98.83%) andAcinetobacter harbinensisHITLi 7( T)(98.14%). TherpoBandgyrBgene sequence analysis confirmed that the strain GC2(T)was a member of genusAcinetobacterand that the closest relative wasAcinetobacter lwoffiiDSM 2403( T)(99.08% and 100% similarity, respectively). DNA-DNA hybridization values between GC2(T)and its closest relatives ranged from 65.6% (withA. lwoffii) to 5.1% (withA. venetianus). The whole genome sequence of strain GC2(T)was obtained. The DNA G + C content of this strain was determined to be 42.9 mol %. ANI indexes, in silico estimations of DDH values and wet lab DDH values demonstrated that strain GC2(T)represents an independent genomospecies. On the basis of phenotypic characteristics, chemotaxonomic, phylogenetic data and DNA-DNA hybridization and whole genome analysis, we propose to assign strain GC2(T)as a new species of the genusAcinetobacter, for which the nameAcinetobacter mesopotamicussp. nov. is proposed. The type strain of this species is GC2(T)(DSM 26953 T = JCM 31073 T). The whole genome of strain GC2(T)has been deposited at DDBJ/ENA/GenBank under the accession JAALFF010000000.Öğe Association of viral load with age, gender, disease severity, and death in severe acute respiratory syndrome coronavirus 2 variants(Wiley, 2022) Acer, Omer; Genc Bahce, Yasemin; Ozudogru, OsmanIn this study, the relationship between viral load, demographic characteristics, and disease information in 1007 (48.5%) patients with Delta variant (B.1.617.2), and 1070 (51.5%) patients with Alpha variant (B1.1.7) were investigated. We found that there was a significant difference in viral load between patients who died from the Alpha variant and those who were discharged (p < 0.05). Nevertheless, no significant difference was observed in patients with the Delta variant. The viral load in patients who died from the Alpha variant was significantly higher than those who were discharged (p < 0.05). The viral load was found to be higher in females in patients with the Delta variant, whereas it was very close in males and females in patients with the Alpha variant (p > 0.05). No significant difference was detected between the cycle threshold values (Ct) and disease severity. In terms of the mean Ct values, statistical differences were observed in patients with Delta and Alpha variants. The Alpha variant was found to have a higher viral load than the Delta variant. Furthermore, the Delta variant was found to be higher in the 40-year-old and under-age group than the Alpha variant, whereas the Alpha variant was higher in the groups over 40 years old. Although the rate of moderate and severe patients in the Alpha variant was found to be higher, the rate of mild survivors was found to be higher in the Delta variant. In conclusion, the increase in vaccination before the appearance of the Delta variant in our region may have influenced the viral load and clinical status of the patients.Öğe Bioaccumulation, Resistance, Removal of U(VI) and Th(IV) and Their Effects on Antioxidant Enzymes on Thermophilic Anoxybacillus flavithermus ST15(Taylor & Francis Inc, 2022) Acer, Omer; Kilinc, Ersin; Ozdemir, SadinIn this research, a novel heavy metals resistance thermophilic Anoxybacillus flavithermus ST15 was isolated from a hot spring mud sample in Afyonkarahisar (Omer). 16S rRNA analyzing revealed that strain ST15 was 99.7% similar to Anoxybacillus flavithermus subsp. yunnanensis str. E13. We propose that U(VI) and Th(IV) have an effect on A. flavithermus at the cellular level and that this bacteria can be used as a bioindicator. Therefore, the effects of U(VI) and Th(IV) resistance, removal, and bioaccumulation on the antioxidant enzyme systems of thermophilic A. flavithermus have been thoroughly investigated. SOD and CAT activities were observed to be increased by different concentrations of U(VI) and Th(IV). A scanning electron microscope and fourier transform infrared spectroscopy were used to analyze changes in the surface macrostructure and functionality of A. flavithermus following interaction with U(VI) and Th(IV). The highest bioaccumulation efficiency amounts for U(VI) were 102.36 mg/g dried bacteria at 24 h at 12.5 mg/l concentration and 105.7 mg/g dried bacteria at 36 h at 12.5 mg/l concentration was detected for Th(IV). At the 24th h and 12.5 mg/l, the highest U(VI) and Th(IV) cell membrane bioaccumulation capacities of A. flavithermus were calculated as 307.08 and 289.52 mg metal/g wet membrane, respectively. This is the first research to examine U(VI) and Th(IV) resistance, removal, and bioaccumulation in thermophilic A. flavithermus.Öğe Bioaccumulation, tolerance, and removal of U(VI) and Th(IV) by a novel thermophilic Bacillus cereus ST14 isolated from hot spring mud samples in Afyonkarahisar, Turkey(Springer Heidelberg, 2024) Ozdemir, Sadin; Acer, Omer; Kilinc, ErsinIn this study, a novel thermophilic Bacillus cereus ST14 with heavy metal tolerance was isolated from a hot spring mud sample in Afyonkarahisar (Omer). 16S rRNA analysis revealed that strain ST14 was mostly related to Bacillus cereus strain 151,007-R3_K09_40_27F (98.18%) and Bacillus cereus strain 2 k (98.10%). We hypothesized that U(VI) and Th(IV) affected B. cereus at the cell level and that this bacterium can be used as a bioindicator. Therefore, U(VI) and Th(IV) tolerance, removal, bioaccumulation, and impacts on antioxidant enzymes of thermophilic B. cereus have been examined in detail. Changes in the surface macrostructure and functionality of B. cereus following interaction with U(VI) and Th(IV) were studied using a scanning electron microscope and fourier transform infrared spectroscopy. B. cereus was found to be highly resistant to 10 and 12.5 mg/L of U(VI) and Th(IV) after 24-h incubation. Superoxide dismutase (SOD) and catalase (CAT) activities were observed to be increased by different U(VI) and Th(IV) concentrations. The highest bioaccumulation capacity quantities were detected as 100.79 and 87.96 mg metal/g dried bacteria at 24th h at 12.5 mg/L concentration for U(VI) and Th(IV), respectively. The highest U(VI) and Th(IV) cell membrane bioaccumulation capabilities of B. cereus have been measured as 318.94 and 263.89 mg metal/g wet membrane, respectively, at 24 h and 12.5 mg/L. This study's findings suggested that B. cereus could be employed as a bioindicator organism for detecting metal contamination in natural or industrial water samples. However, further research should focus on other thermophilic microorganisms.Öğe Carbapenem-resistant Acinetobacter baumannii strains in the Covid-19 pandemic: 16 S rRNA analysis, carbapenem resistance genes, and antibiotic resistance profiles(Springer, 2024) Acer, Omer; Bahce, Yasemin Genc; Ozudogru, OsmanAcinetobacter baumannii was reported as a frequent pathogen leading to outbreaks of multidrug-resistant organisms both in the intensive care unit (ICU) and in non-ICU units during the coronavirus disease in 2019 (COVID-19). In this study we aimed to examine the phenotypic and molecular characteristics of clinical isolates of carbapenem-resistant A. baumannii (CrAb) obtained from Siirt Training Hospital in Siirt, Turkiye, during the Covid-19 pandemic. In our study, 31.6% of the patients whose culture was taken were Covid-19 positive. Of the 57 CrAb strains tested for antibiotic resistance, 52 (91.2%) showed extensive-drug resistance (XDR), 4 (7%) multi-drug resistance (MDR), and 1 (1.8%) pan-drug resistance (PDR). According to 16 S rRNA analysis, the sequences of the CrAb strains used in our study were 99-100% similar to the 16 S rRNA genes of the A. baumannii strains registered in GenBank. The most frequently detected carbapenem resistance gene in the species in our study was the OXA51 gene (85.7%). It's interesting to note that the blaNDM gene, which has a direct connection to the Indian Subcontinent and has recently been observed in the Middle East but has been rarely detected in Turkiye, was discovered in our study at a high rate. We think that this situation is caused by migration from the Middle East due to war in recent years. Additionally, we believe that horizontal gene transfer between bacteria is the cause of the high frequency of the blaVIM gene, whose source is primarily Pseudomonas species, in A. baumannii species in our study.Öğe Carbapenem-resistant Klebsiella pneumoniae strains isolated from clinical specimens in Siirt, Türkiye; molecular characterization and antimicrobial resistance genes detection(Elsevier Science Inc, 2024) Gunes, Sevgi; Acer, Omer; Bahce, Yasemin GencThis study aimed to molecularly identify carbapenem-resistant Klebsiella pneumoniae (CRKP) strains isolated from clinical samples and to determine antibiotic resistance genes. Only carbapenem-resistant strains were included in our study. Of the 35 CRKP strains, 18 (51.4%) were extensive drug, 11 (31.4%) were multi-drug, and 6 (17.1%) were pan-drug resistances. PCR amplification revealed that 25% of the strains carried the OXA-51, 20% the OXA48, and %5 the OXA23 genes. Multilocus sequence typing (MLST) analysis based on seven house-keeping genes revealed sequence type 39. The capsule and O-antigen types were determined as KL103 and O2a, respectively. WGS analysis revealed the existence of (3-lactamase, aminoglycoside, sulfonamide, Phenicol, and Fosfomycinresistant genes. While the K. pneumoniae OmpK37 gene was detected in all 3 strains, the OmpK36 gene was detected only in the CRSU20 strain. This study is important as it is the first study to perform molecular analysis of CRKP strains from Siirt, T & uuml;rkiye.Öğe Effectiveness of Inactivated and mRNA COVID-19 Vaccines Against SARS-CoV-2 Infection, Severe Disease and Mortality in the Geriatric Population(Springer, 2023) Genc Bahce, Yasemin; Acer, Omer; Ozudogru, OsmanOlder age (>60 years) has been identified as the main risk factor for COVID-19. In this study, we aimed to evaluate the efficacy of Pfizer-BioNTech and CoronaVac vaccines against COVID-19 infection, serious illness, and mortality in the geriatric population. We found that 2 doses of CoronaVac vaccine were ineffective in protecting against COVID-19 infection in people over 65 years of age, while the vaccine efficacy (VE) of the mRNA vaccine against COVID-19 was 80% (95% CI 70-87). The VE of full vaccination with BioNTech was 89% (95% CI 53-97) against hospitalization, 79% (95% CI 0-97) against death, and 79% (95% CI 0-97) against intensive care unit (ICU) admission. However, the VE of full vaccination with CoronaVac was 50% (95% CI 33-63) against hospitalization, 53% (95% CI 26-70) against ICU admission, and 56% (95% CI 30-73) against death. In conclusion, we found that the mRNA vaccine has higher efficacy against severe COVID-19 infection and mortality in the geriatric population than the inactivated vaccine. Booster doses of vaccines should be considered in increasing the effectiveness of inactivated vaccines. Given the potential of SARS-CoV-2 mutations evading vaccination protection and the risk of reduced immunity over time, regular monitoring of vaccine effectiveness in the real world is critical.Öğe Evaluating degradation of polycyclic aromatic hydrocarbon (PAH) potential by indigenous bacteria isolated from highly contaminated riverbank sediments(Springer, 2021) Acer, Omer; Johnston, Gloria P.; Lineman, David; Johnston, Carl G.The aim of this study was to identify and culture bacteria indigenous from heavily polycyclic aromatic hydrocarbons (PAH)-contaminated sediments and evaluate their degradative potential. Fifteen novel aerobic PAH degraders mostly associated with Stenotrophomonas, Pseudomonas, Brucella, and Achromobacter genera were isolated. MHR3A, related to Brucellamicroti CCM 4915, MHR3B, related to Pseudomonasputida NBRC 14164, and MHRN15A, related to Achromobacterkerstersii LMG 344, grew aggressively on PAHs as sole carbon sources and were used for degradation studies. With no amendment or added surfactant, within 15 days, MHR3B was able to degrade 78%, 82%, and 57%, respectively of fluorene, phenanthrene, and pyrene (FPP) compared to the controls which were statistically lower. MHR3A was able to degrade 81%, 84%, and 73% of FPP respectively, while MHRN15A was able to degrade 18%, 29%, and 20% of FPP. An anaerobic consortium enriched on FPP, consisting mainly of Gammaproteobacteria and Clostridia, was obtained and tested under sulfate-reducing conditions in the presence of anthraquinone-2,6 disulfonate (AQDS); however, FPP loss attributed to bacteria was only 15% over 120 days. This study demonstrated that isolation and culturing techniques coupled with standard molecular methods warrants continued investigation of indigenous microbes for in situ remediation of highly PAH-contaminated environments.Öğe Evaluation of bacterial agents isolated from endotracheal aspirate cultures of Covid-19 general intensive care patients and their antibiotic resistance profiles compared to pre-pandemic conditions(Academic Press Ltd- Elsevier Science Ltd, 2022) Acer, Omer; Ozudogru, Osman; Bahce, Yasemin GencBackground: Early reports have shown that critically ill patients infected with SARS-CoV-2 have a high prevalence of nosocomial pneumonia, particularly ventilator-associated pneumonia (VAP). Method: In the present study, we determined the bacterial agents isolated from endotracheal aspirate (ETA) cultures of Covid-19 general intensive care patients and evaluated the antibiotic resistance profiles of common bacterial agents compared to the pre-pandemic period.Results: While a total of 119 significant growths with polymicrobial growths were detected in the ETA cultures of 73 (7.5%) of 971 patients hospitalized in the intensive care unit before the pandemic, 87 significant growths were detected in the ETA cultures of 67 (11.1%) of 602 patients hospitalized in the Covid-19 intensive care unit (ICU) after the pandemic. While 61 (83.6%) of patients in the ICU died before the pandemic, 63 (94.0%) of patients in the Covid-19 ICU died after the pandemic. In terms of age, gender, and mortality, there was no significant difference between the two ICUs (p > 0.05). Before the pandemic, the mean length of stay in the ICU was 33.59 +/- 32.89 days, and after the pandemic, it was 13.49 +/- 8.03 days. This was a statistically significant difference (p < 0.05). Acinetobacter baumannii (28.5%), Klebsiella pneumoniae (22.6%), Pseudomonas aeruginosa (15.9%), Staphylococcus aureus (6.7%), Escherichia coli (7.5%), Candida spp. (5.0%) were the most prevalent causal microorganisms discovered in pre-pandemic ICU ETA samples, whereas A. baumannii (54.0%), K. pneumoniae (10.3%), P. aeruginosa (6.8%), E. faecium (8%), and Candida spp.(13.7%) were the most common causative microorganisms detected in Covid-19 ICU ETA samples. Except for tigecycline, antibiotic resistance rates in A. baumannii strains increased following the pandemic. Only tobramycin showed a significant difference in the increase of resistance among these antibiotics (p = 0.037). The rate of tigecycline resistance, on the other hand, was 17.6% before the pandemic and 2.2% afterward (p < 0.05). After the pandemic, increased resistance of K. pneumoniae strains to colistin, meropenem, ertapenem, amoxicillin-clavulanic acid, piperacillin-tazobactam, ciprofloxacin, tigecycline, and cefepime antibiotics was observed. However, these increases were not statistically significant. Except for imipenem, antibiotic resistance rates in P. aeruginosa strains increased following the pandemic. The increase in resistance of ceftazidime and levofloxacin was statistically significant (p < 0.05).Conclusion: As a result, the Covid-19 pandemic requires intensive care follow-ups at an earlier age and with a more mortal course. Although the length of stay in the intensive care unit has been shortened, it is observed that this situation is observed due to early mortality. In P. aeruginosa strains, a significant difference was detected in the resistance increase of the ceftazidime and levofloxacin (p < 0.05) and with the exception of tigecycline, antibiotic resistance rates in A. baumannii strains increased following the pandemic. Only tobramycin showed a significant difference in the increase of resistance among these antibiotics (p = 0.037). Secondary infections in patients create more difficult treatment processes due to both Covid-19 and increasing antibiotic resistance today.Öğe Homologous and Heterologous Covid-19 Booster Vaccinations Against SARS-CoV-2 Infection in the Elderly(Springer, 2024) Acer, Omer; Bahce, Yasemin Genc; Ozudogru, OsmanA third booster doses for the 2019 coronavirus disease (COVID-19) is widely used all over the world, especially in risky individuals, with the recommendation of WHO. The purpose of this study was to evaluate the effectiveness of mRNA (BNT162b2), and CoronaVac (Sinovac Biotech) vaccines as a reminder dose following two doses of CoronaVac against COVID-19 infection, serious illness, and mortality in the geriatric population aged 75 and older during the delta variant dominant period. Our study comprised 2730 individuals the age of 75 and older in total, of which 1082 (39.6%) were male and 1648 (60.4%) were female. The vaccine effectiveness (VE) of 2 doses of CoronaVac + 1 dose of BNT162b2 vaccine combination against COVID-19 was determined as 89.2% (95% Confidence interval (CI) 80.7-93.9%), while the VE of 3 doses of CoronaVac vaccine was determined as 80.4% (95% CI 60.5-90.2%). Geriatric patients who received three doses of CoronaVac vaccine did not need intensive care. No deaths were observed in the vaccinated groups. While the VE of vaccination with 2 doses of CoronaVac + 1 dose of BNT162b2 was 41.8% (95% CI 0-74.1%) against hospitalization, 64.4% (95% CI 0-94.7%) against intensive care unit admission, the VE of vaccination with three doses of the CoronaVac was 78.2% (95% CI 0-96.5%) against hospitalization. In conclusion, our research showed that, even with the emergence of viral variants, a third dose of the CoronaVac and BNT162b2 vaccines is highly effective against symptomatic SARS-CoV-2 infection. Third-dose vaccination regimens, including heterologous and homologous vaccines, can be an effective tool in controlling the COVID-19 pandemic and the emergence of new variants.Öğe Investigation of two different size microplastic degradation ability of thermophilic bacteria using polyethylene polymers(Taylor & Francis Ltd, 2023) Akarsu, Ceyhun; Ozdemir, Sadin; Ozay, Yasin; Acer, Omer; Dizge, NadirThere are several studies stating that many types of microplastics cannot be retained completely by conventional wastewater treatment systems. Therefore, it is necessary to prevent the discharge of these microplastics to the ecological system. The objective of this study was to investigate the biodegradation ability of two different size of PE (50 and 150 mu m) by using two Gram-positive, spore-forming, rod-shaped, and motile thermophilic bacteria, called strain Gecek4 and strain ST5, which can hydrolyse starch, were isolated from the soil's samples of Gecek and omer hot-springs in Afyonkarahisar, Turkey, respectively. Phenotypic features and 16S rRNA analyzing of strains also studied. According to these results, Gecek4s and ST5 were identified as Anoxybacillus flavithermus Gecek4s and Bacillus firmus ST5, respectively. Results showed that A. flavithermus Gecek4s could colonise the polymer surface and cause surface damage whereas B. firmus ST5 could not degrade bigger-sized particles efficiently. In addition, morphological changes on microplastic surface were investigated by scanning electron microscopy (SEM) where dimensional changes, irregularities, crack, and/or holes were detected. This finding suggests that there is a high potential to develop an effective integrated method for plastic bags degradation by extracellular enzymes from bacteria.Öğe Isolation of Thermophilic Bacteria and Investigation of Their Microplastic Degradation Ability Using Polyethylene Polymers(Mdpi, 2022) Ozdemir, Sadin; Akarsu, Ceyhun; Acer, Omer; Fouillaud, Mireille; Dufosse, Laurent; Dizge, NadirMicroplastics (MPs) pose potential public health challenges because of their widespread occurrences in all environmental compartments. While most studies have focused on the occurrence fate of microplastics in wastewater treatment systems, the biodegradation of microplastics in wastewater is generally little understood. Therefore, we used two Gram-positive and thermophilic bacteria, called strain ST3 and ST6, which were identified by morphological, biochemical, physiological, and molecular analyses, to assess the growth and biodegradation potential of two different sized (50 and 150 m) polyethylene particles. The degradation was monitored based on structural and surface morphological changes. According to 16S rRNA analyses, ST3 and ST6 were identified as Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6, respectively. The occurrence of cracks, holes, and dimensional changes was detected by scanning electron microscopy. Moreover, critical characteristic absorption band formation and modifications were determined by Fourier transform infrared spectroscopy. In addition to these, it was found that Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6 produced high level of alpha-Amylase. These results showed that thermophilic bacteria are capable of the biodegradation of microplastics and production of alpha-Amylase.Öğe Phylogeny and polycyclic aromatic hydrocarbons degradation potential of bacteria isolated from crude oil-contaminated soil in Diyarbakir, in the southeast of Turkey(Taylor & Francis Inc, 2021) Acer, OmerIn the present study, four indigenous bacteria designed as OACR6-OACR9 capable of degrading Polycyclic Aromatic Hydrocarbons (PAHs) were isolated from oil-contaminated soils in Diyarbakir city, in Turkey. 16S rRNA gene analysis revealed that strain OACR6 indicated 99.78% homology to Bacillus megaterium NBRC 15308 = ATCC 14581. OACR7, OACR8 and OACR9 strains were found to be members of the Sphingobacterium genus according to genetic analysis. It was observed that the OACR7 and OACR8 strains were 96.63% and 96.94% similar to Sphingobacterium multivorum strain IAM 14316, respectively. On the other hand, strain OACR9 indicated 96.79% homology to Sphingobacterium siyangense strain SY1 16S. GC-MS analyzing revealed that strain OACR6 was able to degrade 68.7% of fluorene and 69.8% of phenanthrene compared to the controls, strain OACR7 was able to degrade 67.5% of fluorene and 65.9% of phenanthrene, strain OACR8 was able to degrade 74.4% of fluorene and 76.4% of phenanthrene and strain OACR9 was found to be able to degrade 67.9% of fluorene and 69.8% of phenanthrene. The findings of this study indicate that the strains investigated have bioremediation potential at oil-contaminated sites and to our knowledge, this is the first study on the biodegradation of PAHs in the oil-contaminated areas in Diyarbakir.Öğe Preconcentrations of Zn(II) and Hg(II) in Environmental and Food Samples by SPE on B. licheniformis Loaded Amberlite XAD-4(Springernature, 2022) Ozdemir, Sadin; Kilinc, Ersin; Acer, Omer; Soylak, MustafaIn this work, the separations and preconcentrations of Zn(II) and Hg(II) ions on Bacillus lichenifoemis loaded onto Amberlite XAD-4 resin by solid-phase extraction has been performed. The biosorbent was characterized by using FT-IR, SEM, and EDX. pH, sample flow rate, eluent type and concentration, amount of B. licheniformis and XAD-4 resin, sample volume, and possible interfering ions effect were investigated in details as experimental variables in the SPE procedure. Limit of detection values for Zn(II) and Hg(II) were detected as 0.03 and 0.06 ng-mL(-1), respectively. 0.2-15 ng-mL(-1) linear range values were achieved for Zn(II) and Hg(II), respectively. Relative standard deviation values were found to be lower than 5%. For validation of the procedure, the certified standard reference materials (CWW-TM-D, EU-L-2, NCS ZC73O14, NCS ZC73350) were analyzed. The concentrations of Zn(II) and Hg( II) in water and food samples were measured by ICP-OES. Consequently, it can be inferred that the immobilized B. licheniformis microcolumn has ideal selectivity for Zn(II) and Hg(II) biosorption.Öğe Risks of catching COVID-19 according to vaccination status of healthcare workers during the SARS-CoV-2 Delta variant dominant period and their clinical characteristics(Wiley, 2022) Ozudogru, Osman; Acer, Omer; Bahce, Yasemin GencThe exposure of healthcare workers (HCWs) to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been a major concern since the beginning of the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to investigate the relationship between vaccination status and the status of catching COVID-19 in HCWs working in a Training and Research Hospital in Turkey, and the clinical course of the disease in those who were caught. The vaccination status of 1279 HCWs working at Siirt Training and Research Hospital during the period when the SARS-CoV-2 Delta variant was dominant, their cases of catching COVID-19 during this period, and the clinical course of the disease in patients with COVID-19 were investigated retrospectively. We found that the rate of COVID-19 transmission was lowest in fully vaccinated HCWs (p < 0.05). The rate of COVID-19 transmission in HCWs who received two doses of BioNTech vaccine (4.4%) and two doses of CoronaVac+ one dose of BioNTech vaccines (2.7%) was considerably lower than those without vaccination (26.2%) (p < 0.05). The transmission rate was lowest among those vaccinated with two doses of CoronaVac+ one dose of BioNTech. Hospitalization was not required in fully vaccinated HCWs. The lymphocyte count was found to be significantly higher in fully vaccinated patients than incompletely vaccinated and unvaccinated patients. Although C-reactive protein (CRP), d-dimer, and ferritin values were higher in unvaccinated and partially vaccinated patients than in fully vaccinated patients, the differences were not statistically significant. As a result, the transmission rate of COVID-19 was lowest in fully vaccinated HCWs and in those vaccinated with two doses of CoronaVac+ one dose of BioNTech. In fully vaccinated HCWs, hospitalization was not needed.Öğe SARS CoV-2 reinfection rate is higher in the Omicron variant than in the Alpha and Delta variants(Springer London Ltd, 2023) Ozudogru, Osman; Bahce, Yasemin Genc; Acer, OmerBackground and objectives Many mutations in variants for instance Delta and Alpha are associated with immune evasion and higher infectious potential. There are uncertainties regarding Omicron. In this regard, we aimed to compare the frequency of reinfection of SARS CoV-2 variants in our hospital between April 22, 2021 and January 26, 2022. Method The reinfection rates and demographic characteristics of a total of 27,487 COVID-19 patients infected with different SARS CoV-2 variants were examined. Results Reinfection was found in 26 (0.46%) of 5554 Alpha, 209 (1.16%) of 17,941 Delta, and 520 (13.0%) of 3992 Omicron variants. A statistically significant difference was observed between the reinfection rates of the variants (p = 0.000). The mean reinfection days were calculated as 204.4 +/- 51.1 in the Alpha variant, 291.2 +/- 58.2 in the Delta variant, and 361.2 +/- 131.6 in the Omicron variant (p = 0.000). It was observed that 16.5% of reinfection cases caught COVID-19 for the second time 3-6 months after the first COVID-19 infection, 36.7% after 6-12 months, and 46.8% after more than 12 months. There was a significant difference between the times in reinfection cases. Most reinfections occurred more than 12 months apart. Among those with a reinfection time > 12 months, 0% had Alpha, 3.4% had Delta, and 96.6% had Omicron variants. Conclusion The highest reinfection rate was observed in the Omicron variant. Reinfection was approximately 30 times more frequent in the Omicron variant than in the Alpha variant and 10 times more frequent in the Delta variant.Öğe Simultaneous preconcentrations of Cu(II), Ni(II), and Pb(II) by SPE using E. profundum loaded onto Amberlite XAD-4(Elsevier, 2021) Ozdemir, Sadin; Kilinc, Ersin; Acer, Omer; Soylak, MustafaIn the present study, we used E. profundum loaded onto Amberlite XAD-4 resin for solid-phase extraction (SPE) of Cu(II), Ni(II), and Pb(II). Some conditions of the SPE procedure, for instance, sample flow rate, pH, eluent type and concentration, the sample volume, amount of E. profundum XAD-4 resin, and the effects of foreign in-terferences ions are discussed in detail. Surface microstructures of the biosorbent were characterized by FTIR, FE-SEM/EDX before and after loading of metals. The biosorption capacities of E. profundum were determined as 49.83, 57.12, and 64.35 mg g(-1) for Pb(II), Cu(II), and Ni(II), respectively. The LOD values were calculated as 0.031 ng mL(-1), 0.042 ng mL(-1), and 0.043 ng mL(-1) for Cu(II), Ni(II), and Pb(II), respectively. The linear range was detected as 0.25-25 ng mL(-1). RSD values were lower than 5%. The concentrations of metal ions in water and food samples were measured by ICP-OES.
