Molecular epidemiological investigation of carbapenem resistant Klebsiella pneumoniae isolated from intensive care unit patients of six geographical regions of Turkey.

INTRODUCTION: Klebsiella pneumonia causes serious infections in hospitalized patients. In recent years, carbapenem-resistant infections increased in the world. The molecular epidemiological investigation of carbapenem-resistant K. pneumoniae isolates was aimed in this study. METHODOLOGY: Fifty carbapenem-resistant K. pneumoniae isolates from six geographical regions of Turkey between September 2019-2020 were included in the study. The disk diffusion method was used for the antibiotic susceptibility testing. The microdilution confirmed colistin susceptibility. Genetic diversity was investigated by MLST (Multi-Locus Sequence Typing). RESULTS: The resistance rates were as follows: 49 (98%) for meropenem, 47 (94%) imipenem, 50 (100%) ertapenem, 30 (60%) colistin and amoxicillin-clavulanate, 49 (98%) ceftriaxone, 48 (96%) cefepime, 50 (100%) piperacillin-tazobactam, 47 (94%) ciprofloxacin, 40 (80%) amikacin, 37 (74%) gentamicin. An isolate resistant to colistin by disk diffusion was found as susceptible to microdilution. ST 2096 was the most common (n:16) sequence type by MLST. ST 101 (n:7), ST14 (n:6), ST 147 and ST 15 (n:4), ST391 (n:3), ST 377 and ST16 (n:2), ST22, ST 307, ST 985, ST 336, ST 345, and ST 3681 (n:1) were classified in other isolates. In Istanbul and Ankara ST2096 was common. Among Turkey isolates, the most common clonal complexes (CC) were CC14 (n:26) and CC11 (n = 7). CONCLUSIONS: In Turkey, a polyclonal population of CC14 throughout the country and inter-hospital spread were indicated. The use of molecular typing tools will highlight understanding the transmission dynamics.

Relationship between IL-17, TNF-α, IL-10, IFN-γ, and IL-18 polymorphisms with the outcome of hepatitis B virus infection in the Turkish population.

OBJECTIVE: Hepatitis B virus is a global threat that can lead to liver cirrhosis and hepatocellular carcinoma. For the treatment of chronic hepatitis B virus, polymorphisms might be an option for gene treatments. This study aimed to investigate the effects of IL-17, TNF-α, IL-10, IFN-γ, and IL-18 gene polymorphisms on hepatitis B virus infection in the Turkish population. METHODS: The genotypes and allele distribution of 75 patients exposed to hepatitis B virus and 50 healthy control individuals were analyzed. The real-time polymerase chain reaction method was used for identification. RESULTS: A correlation was observed between susceptibility to hepatitis B virus infection and IL-17 Exon 3/3'UTR (rs1974226) C, IL-17 Exon 3 (rs763780) A, IL-18 (-607) (rs1946518) A alleles, and IL-17 Exon 3 (rs763780) AA genotype (p=0.006, p=0.009, p=0.025, and p=0.008, respectively). Furthermore, IL-18 (-137) (rs187238) TT genotype and TNF-α-308 (rs1800629) G and A alleles, were associated with protection against hepatitis B virus infection (p=0.0351 and p=0.032, respectively). CONCLUSION: This study demonstrated that TNF-α (-308), IL-17 (Exon 3/3' UTR), IL-17 (Exon 3), and IL-18 (-607) polymorphisms are associated with hepatitis B virus infection. Therefore, these may serve as potential therapeutic targets for chronic viral hepatitis in the Turkish population.

Evaluation of combination therapies with colistin in an experimental mouse pneumonia model induced by carbapenem-resistant Acinetobacter baumannii strain.

The treatment options are limited in Acinetobacter baumannii infections. In this study, the effectiveness of colistin monotherapy and combinations of colistin with different antibiotics were investigated in an experimental pneumonia model induced by carbapenem-resistant A. baumannii strain. Mice in the study were divided into five groups as control (no treatment), colistin monotherapy, colistin + sulbactam, colistin + imipenem, and colistin + tigecycline combinations. The modified experimental surgical pneumonia model of Esposito and Pennington was applied to all groups. The presence of bacteria in blood and lung samples was investigated. Results were compared. In blood cultures, while there was no difference between the control and colistin groups, there was a statistical difference between the control and the combination groups (P = 0.029). When the groups were compared in terms of lung tissue culture positivity, there was a statistical difference between the control group and all treatment groups (colistin, colistin + sulbactam, colistin + imipenem, and colistin + tigecycline) (P = 0.026, P < 0.001, P < 0.001, and P = 0.002, respectively). The number of microorganisms that grew in the lung tissue was found to be statistically significantly lower in all treatment groups in comparison with the control group (P = 0.001). Both monotherapy and combination therapies of colistin were found to be effective in the treatment of carbapenem-resistant A. baumannii pneumonia, but the superiority of combination therapies over colistin monotherapy has not been demonstrated.

Investigation of inflammation, oxidative stress, and DNA damage in COVID-19 patients.

COVID-19 disease, which spreads worldwide, is a disease characterized by widespread inflammation and affects many organs, especially the lungs. The resulting inflammation can lead to reactive oxygen radicals, leading to oxidative DNA damage. The pneumonia severity of 95 hospitalized patients with positive RT-PCR test was determined and divided into three groups: mild, moderate, and severe/critical. Inflammation markers (neutrophil-lymphocyte ratio, serum reactive protein, procalcitonin, etc.) were determined, and IL-10 and IFN-γ measurements were analyzed using the enzyme-linked immunosorbent assay method. In evaluating oxidative damage, total thiol, native thiol, disulfide, and ischemia-modified albumin (IMA) levels were determined by measuring spectrophotometrically. The comet assay method's percentage of tail DNA obtained was used to determine oxidative DNA damage. As a result, when the mild and severe/critical groups were compared, we found that total thiol, native thiol, and disulfide levels decreased significantly in the severe/critical group due to the increase in inflammation markers and cytokine levels (p < 0.05). We could not detect any significance in IMA levels between the groups (p > 0.05). At the same time, we determined an increase in the tail DNA percent level, that is, DNA damage, due to the increased oxidative effect. As a result, we determined that inflammation and oxidative stress increased in patients with severe pneumonia, and there was DNA damage in these patients.

Selenium exerts protective effects on inflammatory cardiovascular damage: molecular aspects via SIRT1/p53 and Cyt-c/Cas-3 pathways.

BACKGROUND: Systemic inflammatory response could affect many systems. Cardiac dysfunction develops due to cardiovascular system damage and could be mortal. Selenium is a trace element that can be used as a dietary supplement and has antioxidant, anti-inflammatory, and anti-apoptotic properties. This study aims to evaluate the protective effects of selenium on cardiovascular damage via silenced information regulator 1 (SIRT1)/p53 and cytochrome C (Cyt-c)/ caspase-3 (Cas-3) pathways. METHODS AND RESULTS: Thirty-two rats were randomly divided into 4 groups as control, LPS (0.1 mg/kg, intraperitoneally(i.p.), 2-7 days) and LPS + Selenium (LPS-0.1 mg/kg, i.p., 2-7 days, selenium - 100 µg/kg, i.p., 1-7 days) and selenium (100 µg/kg, i.p., 1-7 days) group. On the 8th day of the experiment, rats were sacrificed. Blood samples and half of the left ventricles were collected for biochemical and genetic analysis. The remaining left ventricles and aorta were taken for histological and immunohistochemical analysis. In the LPS group myocardial hemorrhages, hyperemia, and endothelial cell loss were observed. Also, Cas-3 and vascular endothelial growth factor (VEGF) expressions; creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), tumor necrosis factor-alpha (TNF-α), ischemia modified albumin (IMA), total oxidant status (TOS), oxidative stress index (OSI) levels; p53, Cyt-c, Cas-3 mRNA expressions increased while total antioxidant status (TAS) levels, glutathione peroxidase (GPx) activity, SIRT1 mRNA expression decreased. Selenium treatment reversed all these changes. CONCLUSION: Selenium showed protective effects on cardiovascular injury via regulating SIRT1/p53 and Cyt-c/Cas-3 pathways. This study enlightened the possible usage of selenium on cardiotoxicity.

Relationship between IL-17, TNF-α, IL-10, IFN-γ, and IL-18 polymorphisms with the outcome of hepatitis B virus infection in the Turkish population

SUMMARY OBJECTIVE: Hepatitis B virus is a global threat that can lead to liver cirrhosis and hepatocellular carcinoma. For the treatment of chronic hepatitis B virus, polymorphisms might be an option for gene treatments. This study aimed to investigate the effects of IL-17, TNF-α, IL-10, IFN-γ, and IL-18 gene polymorphisms on hepatitis B virus infection in the Turkish population. METHODS: The genotypes and allele distribution of 75 patients exposed to hepatitis B virus and 50 healthy control individuals were analyzed. The real-time polymerase chain reaction method was used for identification. RESULTS: A correlation was observed between susceptibility to hepatitis B virus infection and IL-17 Exon 3/3'UTR (rs1974226) C, IL-17 Exon 3 (rs763780) A, IL-18 (-607) (rs1946518) A alleles, and IL-17 Exon 3 (rs763780) AA genotype (p=0.006, p=0.009, p=0.025, and p=0.008, respectively). Furthermore, IL-18 (-137) (rs187238) TT genotype and TNF-α-308 (rs1800629) G and A alleles, were associated with protection against hepatitis B virus infection (p=0.0351 and p=0.032, respectively). CONCLUSION: This study demonstrated that TNF-α (-308), IL-17 (Exon 3/3' UTR), IL-17 (Exon 3), and IL-18 (-607) polymorphisms are associated with hepatitis B virus infection. Therefore, these may serve as potential therapeutic targets for chronic viral hepatitis in the Turkish population.

An investigation of the effectiveness against bacteriuria of silver-coated catheters in short-term urinary catheter applications: A randomized controlled study.

AIM: The aim of this study was to investigate the effectiveness of antimicrobial-coated catheters against bacteriuria and urinary tract infection in patients who have urinary catheterization. METHODS: Twenty eight and twenty six people similar in terms of demographic characteristics and primary and underlying diseases were randomly selected from patients undergoing short-time urinary catheterization in the intensive care unit. Silver-coated slicone foley catheters and normal slicone foley catheters were used for uninary catheterization in the first and second group of the patients respectively. Urine specimens were collected from patients at 2-day intervals and assessed in terms of bacteriuria. RESULTS: Bacteriuria was found in 12 (46.2%) of the patients using normal catheters and 13 (46.4%) of those using silver-coated catheters throughout the monitoring period. No significant relationship was determined between use of different catheter types and bacteriuria (p = 0.98). The most common microorganism was identified as E. coli in the normal catheter group while microorganism other than E. coli was identified in the silver-coated catheter group. The prevalence of bacteriuria was statistically significantly higher in patients with a history of hospitalization in the previous 3 months (p = 0.028). CONCLUSION: The use of silver-coated silicone catheters was not shown to have a protective effect against bacteriuria in this study. Further well-designed studies with larger case numbers are now needed to confirm whether history of hospitalization, which emerged as a statistically significant factor in this study, increases the prevalence of catheter-related bacteriuria.

In vitro activities of linezolid and tigecycline against methicillin-resistant Staphylococcus aureus strains.

Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen that causes morbidity and mortality worldwide. The options for the treatment of MRSA infections are limited. Linezolid is an antibacterial agent of oxazolidinone group. It has a spectrum limited to gram-positive bacteria. Tigecycline is a broad-spectrum antibiotic of glycylcycline group. A total of 60 MRSA strains isolated from various clinical specimens were included in the study. Minimum inhibitory concentrations (MICs) were determined by Etest method, according to the Clinical and Laboratory Standards Institute (CLSI) and Food and Drug Administration (FDA) criteria. The MIC(90) was 1 microg/ml for linezolid (range 0.094-4 microg/ml), and 0.38 microg/ml for tigecycline (range 0.032-1 microg/ml). All strains were found to be susceptible to linezolid, and only one strain's MIC value was above the threshold for tigecycline. Tigecycline and linezolid may represent therapeutic options for infections caused by MRSA.