Mikrobiyoloji bulteni最新文献

{"title":"[Comparison of Three Different Methods in Investigating the Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates].","authors":"Gülşen Uluçam Atay, Gülçin Bayramoğlu, İlknur Tosun, Ülkü Ünsal","doi":"10.5578/mb.202498131","DOIUrl":"https://doi.org/10.5578/mb.202498131","url":null,"abstract":"<p><p>The aim of the study was to evaluate the relationship between carbapenem-resistant Acinetobacter baumannii isolates carrying oxacillinase-type carbapenemase genes with \"international high-risk clones\" (IC I, II, and III) by different molecular epidemiological methods and to statistically compare the concordance and discrimination power of the methods. Carbapenem-resistant and moderately susceptible A.baumannii isolates from non-repeating blood cultures of 72 patients were included in the study. The presence of \"blaOXA-23 , blaOXA-24 , blaOXA-51 ve blaOXA-58 \" genes within OXA-type carbapenemases was detected by polymerase chain reaction (PCR) method and confirmed by DNA sequence analysis. Pulsed f ield gel electrophoresis (PFGE), multilocus sequence typing (MLST) and matrix-assisted laser desorption/ ionization time- of-flight mass spectrometry (MALDI-TOF MS) analyses were performed to evaluate the clonal relations of IC I, II and III clones together with clinical isolates. In the statistical comparison of the methods, discrimination power was evaluated by Simpson index of diversity (SID) and concordance by \"Wallace coefficient\". All of the isolates were found to carry blaOXA-23 and blaOXA-51 genes. As a result of the bioinformatic analysis of the four isolates selected for sequence analysis; blaOXA-23 and blaOXA-51 genes were detected in the selected isolates, and the analysis of two isolates carrying blaOXA-51 gene showed 99% similarity with blaOXA-92 gene. The isolates were clustered into five pulsotypes (A, B, C, D and E) according to ≥ 85% similarity coefficient by PFGE. The isolates and RUH 875, RUH 134, LUH 5875 strains belonging to high-risk clones ICI, ICII and ICIII, respectively, were divided into five main groups [A (n= 58), B (n= 8), C (n= 4), D (n= 4) and E (n= 1)] and 10 subgroups (A1, A2, A4, A5, A6, A9, B1, B4, C3, D1) by PFGE. IC clone III (E1) and seven strains showed singleton PFGE profiles (A3, A7, A8, B2, B3, C1, C2). ICII was found in A5 subtype, ICI in C1 subtype and ICIII in E1 subtype. By PFGE subtype groups, 18 pulsotypes were determined and ST1, ST2, ST81, ST157 and ST604 sequence types were found in 20 isolates randomly selected from pulsotypes according to MLST Pasteur scheme (cpn60, fusA, gltA, pyrG, recA, rplB, rpoB). Principal component analysis (PCA) of the spectra of 72 A. baumannii isolates and ICI, ICII and ICIII clones was performed by MALDI-TOF MS. In PCA analysis, the cluster distance level was defined as 1.5 and the isolates were divided into three clusters. IC clone I, II and III together with 70 clinical isolates were grouped in one cluster, while two clinical isolates (AB083 and AB0115) formed singleton clusters. There was no significant agreement between MALDI-TOF MS; MLST and PFGE data according to Wallace coefficient. It was found that PFGE method gave significant results in terms of discrimination power with SID coefficient, MALDI-TOF MS PCA analysis had the lowest discrimination power value, ","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"97-112"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140853444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Investigation of Cytotoxic and Antileishmanial Activity of Hybrid Silver Nanoparticle Complexes: Potential Drug Candidates against Leishmania Species].","authors":"Yener Özel, İbrahim Çavuş, Umut Yilmaz, Feyzullah Tokay, Sema Bağdat, Ahmet Özbilgin, Mehmet Ünlü, Gülhan Vardar Ünlü","doi":"10.5578/mb.202498184","DOIUrl":"https://doi.org/10.5578/mb.202498184","url":null,"abstract":"<p><p>In recent years, isolation of resistant Leishmania species to drugs in use has made it necessary to search alternative molecules that may be drug candidates. In this study, it was aimed to investigate the cytotoxic and in vitro antileishmanial activity of hybrid silver nanoparticle (AgNP) complexes. In this study, three types of nanoparticles (NPs), oxidized amylose-silver (OA-Ag) NPs, oxidized amylose-curcumin (OA-Cur) NPs and oxidized amylose-curcumin-silver (OA-CurAgNP) nanoparticles were synthesized. The cytotoxic activity of the synthesized nanoparticles was determined against L929 mouse fibroblasts and the in vitro antileishmanial activity was determined against Leishmania tropica, Leishmania infantum and Leishmania donovani isolates by the broth microdilution method. It was observed that the hybrid OA-CurAgNP complex obtained by combining curcumin and silver nanoparticles showed cytotoxic effects against L929 mouse fibroblasts at concentrations of 1074 µg/mL and above. IC50 values expressing the antileishmanial activity of the hybrid OA-CurAgNP complex against L.tropica, L.infantum and L.donovani isolates, were found to vary between 95-121 µg/mL, 202-330 µg/mL and 210-254 µg/mL, respectively. Resistance development has emerged as a major challenge in the treatment of leishmaniasis in recent times. Metallic nanoparticles are considered excellent candidates for medical applications due to their chemical and physical properties, as well as their prolonged circulation in the body. The current drugs used for leishmaniasis treatment are highly toxic, while nanoparticles offer advantages such as low toxicity and easy cellular uptake due to their nanoscale dimensions. The identification of strong efficacy in these particles may contribute scientific evidence for their potential use in leishmaniasis treatment. Therefore, the therapeutical value of OA-CurAgNP complex alone in combination with existing drugs should be examined.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"182-195"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140864275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Detection of Virulence Genes in Pseudomonas aeruginosa Isolates by Polymerase Chain Reaction and Investigation of High-Risk Clones by Matrix Assisted Laser Desorption/ Ionization Time-of-Flight Mass Spectrometer Method].","authors":"Gülşah Karacan Temür, Yeliz Tanriverdi Çayci, Asuman Birinci","doi":"10.5578/mb.202498112","DOIUrl":"https://doi.org/10.5578/mb.202498112","url":null,"abstract":"<p><p>Pseudomonas aeruginosa is a non-fermentative gram-negative bacillus. Many virulence factors play a role in the pathogenesis of P.aeruginosa. The aim of this study was to early detection of ST111, ST175, ST235, ST253, ST395 which are named high-risk clones with increased epidemic potential due to multidrug resistance in P.aeruginosa isolates by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method and to evaluate the relationship between high-risk clones and the presence of P.aeruginosa virulence factors and carbapenemase production genes.P.aeruginosa isolates (n= 100) found to be resistant to at least imipenem or meropenem antibiotics isolated from the various clinical samples in the medical microbiology laboratory between 01.01.2021 and 07.06.2022 were included in the study. For the detection of virulence genes uniplex polymerase chain reaction (PCR) for toxA and multiplex PCR for algD, plcN, lasB, plcH were performed in P.aeruginosa isolates. In the detection of carbapenemase genes, two separate multiplex PCRs used for blaKPC , blaNDM , blaVIM , blaOXA-48 and for blaIMP , blaSPM , blaSIM , blaGIM , blaGES . Investigation of the peaks specific to high-risk clones was performed by using VITEK®-MS (bioMérieux, France) system. P.aeruginosa isolates were mostly isolated from intensive care units (45%) and respiratory tract samples (46%). The antibiotic to which the isolates were found to be most susceptible was amikacin, while highest resistance was detected for piperacillin. In PCR results, toxA, lasB, plcH, plcN and algD were detected as 89%, 99%, 98%, 100%, 100%, respectively. When the presence of characteristic peaks belonging to high-risk clones was evaluated with MALDI-TOF MS, ST253 (7%) and ST175 (2%) were detected. The peaks specific to ST235 and ST395 clones were not detected in our study. blaVIM was detected in two isolates and blaGES-5 carbapenemase was detected in two isolates. Virulence factors were detected at high rates in both high-risk clones and other strains and no significant relationship was found between high-risk clones and virulence factors. Early detection of high-risk clones, identification of antimicrobial resistance mechanisms will help to develop strategic treatment options and prevent their worldwide spread.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"135-147"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140851905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Silencing of Resistance Mechanism in Vancomycin-Resistance Enterococci Using Antisense RNA of vanA Gene].","authors":"Melis Yalçin, Melahat Kurtuluş, Bülent Bozdoğan","doi":"10.5578/mb.202498191","DOIUrl":"10.5578/mb.202498191","url":null,"abstract":"<p><p>The World Health Organization has included the problem of antibiotic resistance among the top 10 important health problems in the world. Treatment of infectious diseases has become more difficult due to the spread of antibiotic resistance between bacteria via transposable elements. Vancomycin-resistant enterococci (VRE) are of critical medical and public health importance due to their association with serious nosocomial infections and high risk of death. One of the most important features of VREs is that they have multiple antibiotic resistance and treatment options are reduced. Therefore, new treatment methods are needed. The vanA gene constitutes the building block of the vancomycin resistance mechanism and causes high resistance to vancomycin. In this study, it was aimed to investigate the neutralization of the vancomycin resistance mechanism by creating vanA antisense RNA (asRNA). The vanA positive VRE50 strain in our culture collection which was isolated from the clinical sample, was used to amplify the vanA gene by polymerase chain reaction (PCR). The amplified vanA amplicon was inserted inversely into the pUC19 plasmid by means of the enzyme cutting sites in the primers used. The resulting plasmid was combined with the pAT392 plasmid which can replicate in gram-positive bacteria and a fusion plasmid was created. The fusion plasmid whose orientation was confirmed, was transferred to the wild strain VRE50 by electroporation method. Minimum inhibitory concentration (MIC) values of transformed VRE (tVRE50) and wild type VRE50 strains used as control were determined by the E-Test method. The vancomycin MIC value of the wild type VRE50 strain was determined as 1024 µg/mL and that of the tVRE50 strain was 32 µg/mL and it was determined that the vancomycin resistance of the tVRE50 strain decreased with asRNA (antisense RNA). Antisense RNA technology is an important method for neutralizing the expression of genes. This study showed that neutralization of the vancomycin resistance gene may provide a lower MIC value in a vancomycin-resistant enterococcus strain and lead to increased susceptibility. This new approach provides a new method for VRE treatment by neutralizing the vancomycin resistance mechanism. The result obtained in this study needs to be supported by in vivo tests.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"125-134"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140858928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Genetic Diversity of Blastocystis in Diarrheal Cases: Identification of Subtypes and Alleles].","authors":"Evren Tileklioğlu, Hatice Ertabaklar","doi":"10.5578/mb.202498207","DOIUrl":"https://doi.org/10.5578/mb.202498207","url":null,"abstract":"<p><p>Blastocystis spp. are the most common intestinal protozoan parasites detected in human stool samples. While identified long before today, its pathogenicity remains controversial. It is generally asymptomatic but in symptomatic cases, many gastrointestinal symptoms, especially diarrhea, have been associated with Blastocystis infection. In recent years, the relationship between the symptoms observed in cases and Blastocystis subtypes (ST) has been reported. The aim of this study was to detect Blastocystis in diarrheal cases admitted to the Aydın Adnan Menderes University Faculty of Medicine, Department of Parasitology Laboratory, to determine subtypes and allele diversity and to investigate its relationship with clinical symptoms. For this purpose, diarrheal stool samples of 200 cases were included in the study and their demographic characteristics (age, gender, residence) and clinical findings (abdominal pain, dyspepsia, nausea-vomiting, weakness, weight loss, anal itching, rash, urticaria) were recorded. Blastocystis was detected by direct microscope method (DM) and by molecular analyses which were performed with polymerase chain reaction (PCR). Subtype diversity was determined based on DNA sequence analysis by PCR targeting the Blastocystis ribosomal ribonucleic acid small subunit (SSU rRNA) gene. In addition, alleles related to Blastocystis subtypes were determined and statistically compared between all data and clinical findings. In the current study, Blastocystis was detected in 31 (15.5%) samples by DM and in 35 (17.5%) samples by PCR specific to the Blastocystis SSU rRNA gene among 200 diarrheal stool samples. No statistical difference was detected between Blastocystis and demographic characteristics. Dyspepsia and nausea-vomiting symptoms differed significantly in cases with Blastocystis compared to negative ones (p= 0.0025, p= 0.0498). Blastocystis subtype was detected in 33 samples by SSU rRNA sequence analysis, and the subtype distribution was ST1 (n= 10, 30.3%), ST2 (n= 4, 12.1%) and ST3 (n= 19, 57.6%). In the statistical evaluation between clinical findings and Blastocystis subtypes, a relationship was found between dyspepsia and Blastocystis ST3 (p= 0.0039). The allele diversity of Blastocystis subtypes was determined as allele 4 (10/10) in all ST1, allele 11 (2/4) and 12 (2/4) in ST2, allele 34 (14/19), 36 (4/19), and 38 (1/19) in ST3. In conclusion, our study provides important data on the molecular epidemiological characteristics of the Blastocystis by determining positivity, subtypes and alleles in diarrheal cases. Therefore, within the scope of the one health approach, comprehensive molecular epidemiological studies are required to determine the presence and genotypes of Blastocystis in human, animal and environmental samples.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"196-208"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140864454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Lomentospora prolificans Fungemia in a Patient With T-Cell Large Granular Leukemia: A Rare Pathogen in Türkiye].","authors":"Esat Kıvanç Kaya, Mustafa Berkay Taştekin, Sevtap Arikan Akdağli, Dolunay Gülmez, Arzu Topeli, Ömrüm Uzun","doi":"10.5578/mb.202498145","DOIUrl":"https://doi.org/10.5578/mb.202498145","url":null,"abstract":"<p><p>Scedosporium/Lomentospora is an opportunistic fungal pathogen found worldwide. While Scedosporium apiospermum and Scedosporium boydii are commonly observed globally, Lomentospora prolificans, which mainly affects immunosuppressed individuals, is rarely encountered and is more prevalent in arid climates, particularly in Australia and Spain. L.prolificans is a fungus commonly found in environmental sources such as contaminated water and soil. This species is known as an opportunistic pathogen that can cause deep-seated fungal infections, especially in immunosuppressed individuals. In this case report, a fatal case of L.prolificans fungemia in a patient with T-cell large granular leukemia during profound neutropenia was presented. The patient admitted to the hospital with prolonged fever, neutropenia, and shortness of breath. Antibiotherapy was administered to the patient for febrile neutropenia, but the fever persisted and his clinical status rapidly deteriorated. L.prolificans was isolated from the blood culture, and considering its antifungal resistance, combination therapy of voriconazole and terbinafine was initiated. However, the patient died of septic shock and multiple organ failure. In conclusion, although L.prolificans infections are rare, they can be life-threatening, especially in immunosuppressed individuals. Diagnosis and treatment of such infections may be difficult, therefore rapid diagnostic methods and appropriate treatment protocols should be developed. Consideration of infections caused by rare fungal pathogens in patients with risk factors may be critical for patient care. The literature review revealed that the first case of L.prolificans fungemia from Türkiye was reported in 2023. This case presentation represents the second reported case. However, in our case, L.prolificans fungemia occurred in 2018, it can be considered that L.prolificans may have been an invasive fungal pathogen of significant concern in Türkiye much earlier than previously documented.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"209-219"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140868441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[A Case of Thyroid Gland Abscess Caused by Brucella melitensis].","authors":"Ilgaz Kazaz, Ertuğrul Yazici, İsmail Selçuk Aygar, Tuğrul Hoşbul","doi":"10.5578/mb.20249810","DOIUrl":"10.5578/mb.20249810","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Brucellosis is a zoonotic disease endemic in many developing countries, including Türkiye. Among the species that are pathogenic for humans; Brucella melitensis is isolated from livestock animals like sheep and goats, Brucella abortus from cattle and Brucella suis from pigs. Laboratory diagnosis of infection caused by Brucella species with gram-negative coccobacillus morphology; can be made through characteristic culture features, serological tests and molecular methods. Brucellosis, which has a wide distribution of clinical signs and symptoms; can cause various complications by affecting many organs and systems. Among all complications, the probability of thyroid abscess is less than 1%. In this case report; an example of thyroid abscess, one of the rare complications of brucellosis that is not frequently encountered in the literature, was presented. During the physical examination of a 45-year-old female patient who admitted with the complaint of pain in the neck area, fever, neck swelling, redness and pain that increased with palpation were detected. Leukocytosis, lymphopenia, high sedimentation and CRP, low TSH and high T4 values were detected in laboratory tests and subacute thyroiditis was considered as the preliminary diagnosis. Surgical abscess drainage was planned as the patient's clinical findings progressed during follow-up and spontaneous pus discharged from the midline of the neck. The abscess aspirate sample taken during surgical intervention and the blood culture samples taken before were evaluated microbiologically. Microorganisms that did not grow on EMB agar but grew on 5% sheep blood and chocolate agar at the 72-96th hour of incubation of culture plates; were detected to have gram-negative coccobacillus morphology and positive for catalase, oxidase and urease. Although the Wright test was negative with a titer of 1/20, the Rose Bengal test was positive, Coombs test was positive with a titer of 1/160 and the Brucellacapt test was positive with a titer of &gt;1/5120. Microorganisms growing on culture plates were identified as B.melitensis at the species level with specific antisera. As a result of antibiotic susceptibility tests evaluated according to the European Committee on Antimicrobial Susceptibility Testing version 14.0 (EUCAST v14.0), the isolate was susceptible to rifampicin, doxycycline, gentamicin and trimethoprim-sulfamethoxazole at standart dosing regimen and susceptible to ciprofloxacin and levofloxacin at increased exposure. The patient, who was started on doxycycline and rifampicin combination treatment, was discharged without any complaints. In the diagnosis of infection due to Brucella species, which is one of the pathogens that early diagnosis and initiation of treatment greatly affects the prognosis; in addition to culture, which is the gold standard method, serological tests are also very important. If diagnosis is delayed, complications may develop due to involvement in almost every part of the body, depen","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"217-223"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140851904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Evaluation of Toll-Like Receptor Gene Expressions in Encephalitozoon intestinalis Infection].","authors":"Erdi Uzun, Ülfet Çetinkaya","doi":"10.5578/mb.202498201","DOIUrl":"https://doi.org/10.5578/mb.202498201","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Microsporidia are obligate intracellular pathogens that can infect many vertebrate and invertebrate hosts. While the Microsporidia phylum was defined as protozoa until the 1990s, it has been associated with fungi in line with the data obtained as a result of phylogenetic and molecular analyzes in recent years. Although approximately 200 genera and 1400 Microsporidia species related to these genera have been reported to date, only 14 species are known to cause infection in humans. Encephalitozoon intestinalis is one of the most frequently detected species in humans and causes serious clinical conditions in immunosuppressed individuals. Little information is available about the immunology of this infection. This study was aimed to investigate the changes in Toll-Like receptor (TLR) gene expressions in Madin-Darby canine kidney (MDCK) cells treated with E.intestinalis spores. Three groups were formed in the study. In the first group, only the medium prepared for E.intestinalis was added to the MDCK cells. In the second group, 108 live spores waiting at +4 °C were added. In the third group, 108 heat-inactivated spores were added. All three groups were incubated at 37ºC with 5% CO2 . RNA isolation and cDNA synthesis were performed from samples taken from these groups at the 1st, 3rd, 6th, 12th and 24th hours. Expression of TLR1-10 genes from the obtained cDNAs was evaluated by real-time polymerase chain reaction (Rt-PCR). GAPDH and ACTB genes were used as housekeeping genes in the study. Target genes were normalized by taking the average of these two genes and statistical analysis was performed by applying the 2-ΔΔCt formula. Genes detected above the threshold value (threshold 1) were considered to have increased expression. Genes detected below the threshold value were considered to have decreased expression. The growth of the live and inactive spores were followed simultaneously with the experimental groups. Approximately two weeks after the start of the culture, it was observed that E.intestinalis grew in the culture with live spore, but did not grow in the culture with inactivated spores. No statistically significant change was observed in gene expressions in the inactivated spore group. In the live spore group, a significant increase was seen in the expression of only two genes. These genes were TLR3 and TLR4. It was observed that there was a significant increase in TLR3 gene expression at the first hour (1.6-fold of control group) but the expression level started to decrease at the third hour (1.4-fold of control group) and returned to the control level at the sixth hour. It was observed that TLR4 gene expression continued parallel to the control until the 24th hour and increased significantly (2.1-fold of control group) at the 24th hour. In conclusion, this study is the f irst report in which the changes in ten different TLR gene expressions were evaluated at different times in MDCK cells stimulated with E.intestinalis and the change in T","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"171-181"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140851389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Molecular Analysis of Antibiotic Resistance in CarbapenemResistant Pseudomonas aeruginosa Isolates Isolated from Clinical Samples].","authors":"Gülşah Altan, Erva Rakici, Osman Birol Özgümüş","doi":"10.5578/mb.202498200","DOIUrl":"https://doi.org/10.5578/mb.202498200","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Pseudomonas aeruginosa is an opportunistic pathogen that causes increased morbidity and mortality in risky patient groups. Nowadays, carbapenem resistance has become a threat and resistance genes are spreading among species through mobile genetic elements. The dissemination of carbapenemases among P.aeruginosa is a serious public health concern due to its limited options for the treatment of bacterial infections. In this study, it was aimed to investigate the molecular epidemiology of 47 carbapenem resistant P.aeruginosa (CRPA) isolates derived from various clinical samples from the Central Laboratory Bacteriology Unit of Kocaeli University Research and Training Hospital between October 2021 and March 2023. The rates of resistance to the antibiotics, some carbapenemase and virulence genes, conjugative resistance plasmids, integron gene cassette contents and the clonal similarity of the isolates were investigated and then epidemiologically evaluated. In the study, identification of the bacterial isolates and their susceptibility to some antibiotics (imipenem, meropenem, aztreonam, amikacin, netilmicin, tobramycin, piperacillin, piperacillin/tazobactam, ceftazidime, cefepime, ciprofloxacin and levofloxacin) were determined by the VITEK® 2 Compact automated system. Metallo-beta-lactamase (MBL) production of the isolates was demonstrated by the imipenem/meropenem-EDTA (IMP/MEM-EDTA) combined disc method. Conjugation experiments were performed by the broth mating method. Alkali lysis method was used in plasmid DNA isolations. Co-transferred antibiotic resistances in transconjugants were detected by disc diffusion method. Carbapenemase genes (blaIMP , blaVIM , blaNDM , blaKPC and blaOXA-48 ), integron gene cassettes (class 1 and class 2) and virulence genes (lasR and rhlR) were screened by specific polymerase chain reactions (PCRs). Clonal relationships of the CRPA isolates were investigated by evaluating the DNA f ingerprintings obtained from the ERIC (enterobacterial repetitive intergenic consensus)-PCR assay. The highest resistance rate of the isolates were to levofloxacin, while the lowest resistance rates were observed against tobramycin, gentamicin and amikacin. MBL production was detected in 25 (53.2%) isolates. In conjugation experiments, 12 (25.5%) isolates were detected to harbour conjugative resistance plasmids. In 90% of the CRPA isolates, lasR and rhlR biofilm genes (encoding for the transcriptional activator protein) were detected by PCR. The blaVIM gene was detected in six (12.8%) isolates. The blaNDM gene was detected in five (10.6%) isolates and the blaOXA-48 gene was detected in three (6.4%) isolates. The blaKPC and blaIMP genes were not detected in CRPA isolates. It was determined that two (16.6%) of the isolates that carried the blaVIM gene, one (8.3%) carried the blaNDM gene and one (8.3%) carried the blaOXA-48 gene contained conjugative plasmids.In integron-specific PCRs, intI1 gene was positive in 39 (82.9%) isolates, while","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"148-170"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140852411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Investigation of the Antibacterial Synergistic Activity of Fosfomycin-Teicoplanin Combination in Methicillin-Resistant Staphylococcus aureus Strains Isolated from Various Clinical Sample].","authors":"Rümeysa Tuba Biçer, Tuncer Özekinci, Mücahide Esra Koçoğlu","doi":"10.5578/mb.202498156","DOIUrl":"https://doi.org/10.5578/mb.202498156","url":null,"abstract":"<p><p>The aim of this study was to investigate the detection of teicoplanin and fosfomycin antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) strains by different methods and to evaluate the antibacterial synergistic effect of teicoplanin-fosfomycin combination by using checkerboard assay and time kill curve assay. Forty-five MRSA strains isolated from clinical samples in routine medical microbiology laboratory of Göztepe Prof. Dr. Süleyman Yalçın City Hospital were included in the study. In the first stage of the combination study, minimum inhibitory concentrations (MIC) were investigated by broth microdilution for teicoplanin and by both broth microdilution and agar dilution methods for fosfomycin. The combination of teicoplanin and fosfomycin was tested by the checkerboard method in 45 MRSA strains and combination effect was determined according to fractional inhibitory concentration index (ΣFIC) calculation. The synergistic effect and bactericidal activity of antibiotic combination were studied against a randomly selected strain from the strains used in the study by using time-kill method for 24 hours. As a result of teicoplanin and fosfomycin antibiotic susceptibility studies, all isolates were found to be susceptible to both antibiotics according to the susceptibility breakpoints determined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). A synergistic effect was found in 22 (49%), additive effect in 22 (49%) and indifferent effect in one (2%) of the 45 strains studied with the checkerboard method. The mean ΣFIC of 45 isolates was found to be 0.5. In the combination study of the antibiotics of the isolate that was studied with time-kill method, synergism was detected for 1/8 MIC concentrations at 12th hour and 24th hour and synergism at 1/4 MIC concentration at sixth hour, 12th hour and 24th hour. In the combination study of 1/4 MIC concentrations of antibiotics, bactericidal effect was detected at sixth hour and this effect was observed to disappear at 12th and 24th hours. High rate of synergistic antibacterial effect of teicoplanin-fosfomycin combination on MRSA isolates was demonstrated as a result of in vitro tests. Such studies conducted on antibiotic-resistant bacterial infections will provide clinicians different treatment options and will contribute to increasing survival. As a result of this study, provided that it is supported by future clinical studies, it can be stated that the teicoplanin-fosfomycin combination may be an effective treatment option in community and hospital-acquired infections caused by MRSA.</p>","PeriodicalId":18509,"journal":{"name":"Mikrobiyoloji bulteni","volume":"58 2","pages":"113-124"},"PeriodicalIF":1.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140865824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}