Mikrobiyoloji bulteni最新文献

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic viral disease. MicroRNAs (miRNAs), which play an important role in the regulation of gene expression, are involved in many processes essential for cell life such as development, differentiation, survival, apoptosis and aging. If miRNAs fail to fulfill their functions, they cause susceptibility to many diseases, including viral infections or cause the disease to be experienced in different clinical situations, such as severe or mild. In this study, we aimed to determine the expression levels of hsa-miR-144 and hsa-miR-1908 in CCHF patients and to compare the results in different clinical courses of CCHF disease. In this study, expression levels of hsa-miR-144 and hsa-miR-1908 were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR) in blood samples obtained from 60 CCHF patients and 40 healthy individuals. We also investigated the differences in the expression levels of the microRNAs between patients with severe and non-severe disease or between patients who died and survived. Quantitative polymerase chain reaction data were uploaded to the "Data Analysis Center" (Qiagen, Germany) and analyzed using the ΔΔCq (ΔΔCt) method. p value was calculated according to Student's t test for genes in the study groups. The expression level of hsa-miR-144 decreased (fold change= 0.09) and the expression level of hsa-miR-1908 increased 1.44-fold in CCHF patients compared to the control group. The expression of hsa-miR-144 and hsa-miR-1908 increased 2 and 2.36-fold, respectively, in severe patients compared to non-severe patients. The expression levels of hsa-miR-144 and hsa-miR-1908 were 16.3- and 14.3-fold higher, respectively, in fatal cases compared to surviving patients and these results were statistically significant. In addition, the expression level of hsa-miR-144 was significantly decreased in patients with low leukocyte counts and the expression level of hsa-miR-1908 was significantly increased in patients with prolonged prothrombin time (PT). This is the first study in the literature investigating the expression level of hsa-miR-1908 in CCHF patients. In conclusion, the data of this study suggest that hsa-miR-144 and hsa-miR-1908 may be important biomarkers in predicting the prognosis and clinical course of CCHF disease.

Tuberculosis continues to be an important public health problem worldwide. Culture methods are still considered the gold standard in the diagnosis of tuberculosis and the determination of drug resistance. The most important limitation of these methods is their long turnaround time. Commercial culture systems developed to shorten the duration are emerging as an economic problem, especially for developing countries. Therefore, cheap, fast, easy to apply and objectively evaluable tests are needed. In this study, in addition to culture-based methods for determining RIF and INH resistance in Mycobacterium tuberculosis complex isolates, it was aimed to develop the capillary tube method to accelerate the evaluation process. The study included 27 RIF-resistant, 36 RIF -sensitive, 30 INH-resistant, and 33 INH-sensitive isolates obtained from the mycobacteriology laboratory culture collection, for which susceptibility testing to firstline drugs were previously performed using the BACTEC MGIT 960 system (BD, USA) and were stored. H37Rv standard strain and an external quality control strain (IDT3) with known RIF and INH resistance were used as quality control isolates in the study. As a new testing method, the capillary tube method for detecting rifampicin and isoniazid resistance was compared to the standard BACTEC MGIT 960 system. In the determination of RIF and INH resistance, the sensitivity of the capillary tube method compared to the reference method was determined as 85% and 80%, respectively; however, the specificity values (25% and 45.5%, respectively) for both drugs were found to be low in the studies. The time to detect resistance with the capillary tube method varied between 4-9 days. Capillary tube method, which was developed especially for the rapid identification and treatment of multidrug-resistant isolates, is promising in that it detects resistant strains in a short time with a relatively high sensitivity, although its specificity is very low. It is thought that it would be beneficial to continue the study with a larger number of samples and even improve the method with studies conducted directly from clinical samples.

Polymerase chain reaction (PCR) and antigen test (AgT) are frequently used in the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Routine PCR tests that detect the virus genome cannot determine whether the virus is infectious or not. However, detection of subgenomic RNA (sgRNA) produced during the replication period may indicate active viral infection. Active virus detection can offer various health and economic benefits from isolation time to treatment. Antigen tests are also considered as indicators of infectiousness since they can detect viruses above a certain load amount. The aim of this study was to use two different subgenomic RNAs and antigen test instead of genomic RNA to examine the relationship with each other and the clinic in terms of infectiousness. Evaluating the antigen test together with subgenomic RNA as an indicator of infectiousness may show the importance of this test. SARS-CoV-2 PCR positive 109 naso/oropharyngeal swab samples stored at -80 °C were included in the study. In order to confirm the PCR positivity of these samples, E gene PCR was performed and AgT, and E and N sgRNA quantitative real-time reverse transcription-PCR (RT-qPCR) detection was performed. Of the 109 SARSCoV-2 PCR positive samples, 83 (76.14%) had antigen test positivity, 88 (80.73%) had E gene sgRNA, 96 (88.07%) had N gene sgRNA and 97 (89%) had at least one sgRNA positivity.The antigen test was found positive in 77.3% of the samples in which at least one sgRNA was detected and in 66.7% of the negative samples and this difference was not statistically significant (p= 0.475). The difference between E sgRNA and AgT positivity was significant (p= 0.023). N sgRNA was positive in 98.9% of E sgRNA positive samples and 42.9% of the negative samples and this difference was statistically significant (p= 0.0001). The AgT positivity rate was found to be 98.15% (53/54) for cycle threshold (Ct) value ≤ 25, 57.14% (12/21) for Ct 25-30, and 52.94% (18/34) for Ct ≥ 30. The difference in antigen test positivity between E gRNA Ct value ≤ 25 and > 25, ≤ 29 and > 29, < 30 and ≥ 30 was statistically significant (p= 0.0001). Antigen test positivity appears to be associated with viral load and infectivity, as expected. In our study, it has been shown that sgRNAs and AgT which are indicators of infectiousness can be detected at least 10 days after the symptom period. Using these two tests together could detect infective individuals with higher accuracy and shorten the duration of hospital stay and isolation.

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.

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.

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.

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.

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.

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 >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