BK Virus Infections and Hemorrhagic Cystitis in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

BK virus (BKV) associated with hemorrhagic cystitis (HC) is the most important complication that develops after hematopoietic stem cell transplantation (HSCT) in patients with hematological malignancies. This study aims to investigate BKV infections and HC in pediatric patients after allogeneic hematopoietic stem cell transplantation. Between November 2018 and November 2019, a total of 51 patients between the ages of 11 months and 17 years were included in the study. BKV Bosphore ® v1 quantification kit (Geneworks Anatolia, Turkey) was used for the detection of BKV DNA in urine and blood samples. Among the total of 51 patients, the incidence of BKV infection was found to be 86.3%. Allogeneic HSCT was performed in 40 patients and autologous HSCT in 11 patients. BK viruria and/or viremia were detected in 85% (44) of patients who underwent allogeneic HSCT and in 90% in the autologous group. High-level BK viruria (>107 copies/mL) was found in 41% (9) of 22 patients who were BKV positive before transplantation, while in 27.5% (8) of 29 patients who were BKV negative before transplantation; thus, BKV positivity before transplantation was considered a risk factor for high-level BK viruria. Acute GVHD developed in 6 of 40 patients in the allogeneic group. HC was prevented in 12 (67%) of 18 patients who received preemptive treatment, while HC developed in 6 (33%). HC occurred at a median of 35 days (17-49 days) post-transplant. Despite preemptive treatment, 6 (15%) patients who developed HC associated with BKV were in the allogeneic group but not in the autologous group. Of these patients with HC, 5 received a myeloablative treatment regimen, and 1 patient was given a reduced-intensity treatment regimen. The viral load in urine was found to be 107-9 copies/mL within 2 weeks before the development of HC and has been identified as a prognostic indicator. In conclusion, early diagnosis of viral infections by monitoring BKV viral load in HSCT patients will be effective in preventing the progression of complications such as BKV-associated HC by providing timely initiation of preemptive treatment.

Investigation of the Relationship between Colistin Resistance and Capsule Serotypes in Carbapenem Resistant Klebsiella pneumoniae Strains.

Carbapenem-resistant Klebsiella pneumoniae is associated with high morbidity and mortality, and capsule serotypes make treatment difficult. The aim of this study is to investigate the relationship between colistin resistance and capsule types in carbapenem-resistant K. pneumoniae isolates. In 2018- 2020, we conducted our study with 115 carbapenem-resistant K. pneumoniae strains diagnosed by matrix-mediated laser desorption ionization time-of-flight mass spectrometry method (MALDI-TOF MS; Bruker Daltonics, Germany). Colistin sensitivities were determined by using DxM MicroScan WalkAway System (Beckman Coulter, ABD) automated system and were then verified by liquid microdilution (MIC). Capsule serotypes were investigated by conventional polymerase chain reaction (PCR) method. Among the carbapenem resistant K. pneumoniae isolates, 42% (48) were resistant to colistin and 58% (67) were susceptible to colistin. In the K. pneumoniae isolates with colistin resistance 33% (16) K5, 13% (6) K2, 8% (4) K20 4% (2) K1 and 2% (1) K54 and K57 capsule serotypes were found, while in the K. pneumoniae isolates with colistin susceptible 12% (8) K5, 4% (3) K2, 3% (2) K20, 1.5% (1) K1 and K54 capsule serotypes were found. Serotype K5 was very frequent in isolates collected from patients with urinary tract diseases. The resistance profile data obtained from the present study can serve as an information base to understand the infection pattern prevailing in the hospital.

[Detection of influenza virus infections by molecular and immunofluorescence methods]. / Influenza virüs enfeksiyonlarinin moleküler ve immün floresan yöntemlerle saptanmasi.

Influenza virus infections are extremely important for human health due to the occurence of seasonal epidemics and pandemics worldwide. Influenza is associated with high morbidity and may result in serious complications such as life threatening viral or bacterial pneumonia. Especially, young children, older adults, patients with chronic diseases such as heart, lung, kidney, and diabetes and immunosuppressed people are at higher risk for complications and death from influenza virus infections. The aim of this study was to determine the incidence of influenza type A and B virus infections and influenza A virus subtypes in hospitalized patients with respiratory tract infections by real-time reverse transcriptase-polymerase chain reaction (RT-PCR, Sacace, Italy), conventional RT-PCR and direct immunofluorescence antibody (DFA, Argene SA, France) tests. Nasopharyngeal swab specimens were collected from a total of 476 patients with respiratory tract symptoms by using flocked swabs (Copan Diagnostics, Italy) between 1 April 2012 and 31 December 2013. Influenza A virus was detected in 20.5% (98/476) and influenza B virus in 3.3% (16/476) of the cases by real-time RT-PCR test. During the study period, 63.3% of 98 influenza virus isolates were found as influenza A(H1N1)pdm09 and 36.7% were influenza A(H3N2) subtypes. Influenza A (H1N1) pdm09 subtype was observed in 12 cases in January 2013 and influenza A(H3N2) subtype was observed in 11 cases in December 2013 as the highest values. When the real-time RT-PCR test was regarded as the reference test, the sensitivities of DFA test for influenza A and B and conventional RT-PCR test with WHO primers (M30F2/08 and M264R3/08) for influenza A were detected as 72.4%, 75%, 96% and the specificities were detected as 99.2%, 99.5% and 100%, respectively. In conclusion, influenza A virus infection was detected rather high with a rate of 20.5% in the study group. The monitoring of influenza virus types and subtypes is required for the evaluation of influenza vaccine strains and circulating influenza viruses and for the identification of subtypes with pandemic potential. Planning for appropriate antiviral therapy using real-time RT-PCR in the early diagnosis of influenza virus infections will significantly contribute to the management of the patient's treatment. Thus, unnecessary drug use will be prevented and controlled with effective treatment of the disease at the time of infection.