Bahar Akgün Karapınar

Background/Objectives: Patients with rheumatic diseases have an increased burden of infection owing to biological disease-modifying antirheumatic drug (bDMARD) therapy. Therefore, vaccination is crucial for the prevention of infection in these patients. In this case–control study, we aimed to evaluate vaccine response to hepatitis B, pneumococcus, and measles using antibody titers in patients undergoing biological therapy. Methods: This study included 16 patients aged 5–18 years of age who received bDMARD treatment and 20 healthy controls. Serum samples of the patients were collected at baseline and subsequently on the 3rd and 6th months after bDMARD therapy, and IgG antibodies against pneumococcal capsular polysaccharide antigen (PCP), measles, and hepatitis B were measured. Results: There were no statistically significant differences in mean anti-HBsAg, anti-PCP, and anti-measles antibody titers between the study and control groups. The percentages of patients with anti-HbsAg, anti-PCP, and anti-measles protective antibodies were 68.8% (n = 11/16), 100% (n = 16/16), and 56.25% (n = 9/16), respectively. There were no statistically significant differences in the mean antibody titers at baseline and 3rd month. Only the anti-measles IgG titer level decreased below 200 (mIU/mL) in one patient in the 3rd month and in two patients in the 6th month. Conclusions: Patients with low or declining hepatitis B and measles antibody titers before or during bDMARD treatment may require close monitoring to ensure adequate protection against vaccine-preventable diseases. Regular screening and follow-up are essential in this patient population.

Bacteremia and fungemia are significant causes of morbidity and mortality that frequently occur as co-infections with viral respiratory infections, including SARS-CoV-2. The aim of this study was to evaluate the microorganisms that were isolated from the blood cultures of SARS-CoV-2-positive and negative patients and investigate their antimicrobial resistance patterns. A retrospective analysis was performed of 22,944 blood cultures sent to the laboratory between November 2020 and December 2021. Blood culture analyses were performed using the BD Bactec FX automated system. Identification was carried out using conventional methods, namely, VITEK-2 and MALDI-TOF MS. Antibacterial/antifungal susceptibility tests were performed according to EUCAST/CLSI recommendations. SARS-CoV-2 tests were performed with RT-PCR. Culture positivity was detected in 1630 samples from 652 patients. Of these 652 patients, 633 were tested for SARS-CoV-2; 118 (18.6%) were positive and 515 (81.3%) were negative. The bacteria and fungi that were isolated at the highest rate in SARS-CoV-2-positive patients were methicillin-resistant coagulase-negative staphylococci (MR-CoNS) (21.5%), Escherichia coli (12.4%), Klebsiella pneumoniae (12.4%), Candida albicans (1.65%), and Candida glabrata complex (1.65%), while in the negative patients, the highest rates were for E. coli (21.3%), MR-CoNS (13.5%), K. pneumoniae (12.05%), C. albicans (2.1%), Candida parapsilosis (1.1%), and Candida tropicalis (0.9%). No statistically significant difference was determined between COVID-19-positive and negative patients in terms of detection, such as with the Pseudomonas spp., Enterococcus spp., and methicillin-resistant Staphylococcus aureus isolated from the blood cultures (p > 0.05). The most common isolate was MR-CoNS in SARS-CoV-2-positive patients (p = 0.028). Acinetobacter baumannii was more frequent (p = 0.004) and carbapenem-resistant K. pneumoniae was isolated at a higher rate (60% vs. 43%) in SARS-CoV-2-positive patients compared to SARS-CoV-2-negative patients (p > 0.05). These findings highlight the fact that isolation procedures should not be disregarded and the distribution of bacterial/fungal agents of bloodstream infections and their antibiotic resistance should be followed up during a pandemic, such as in the case of COVID-19.

Bacteremia and fungemia are significant causes of morbidity and mortality which frequently occur as co-infections with viral respiratory infections including SARS-CoV-2. It was aimed to evaluate the microorganisms isolated from blood cultures of SARS-CoV-2 positive and negative patients and investigate their antimicrobial resistance patterns. A retrospective analysis was performed with the total number of 22,944 blood cultures sent to the laboratory between November 2020 and December 2021. Blood cultures were performed on the BD Bactec automated system. Identification was performed using conventional methods, VITEK-2 and MALDI-TOF MS. Antibacterial/antifungal susceptibility tests were performed according to EUCAST/CLSI recommendations. SARS-CoV-2 tests were performed with RT-PCR. It was detected 1,630 culture positivity belonging to 652 patients. Totally 633 of 652 patients were tested for SARS-CoV-2; 118 (18.6%) were positive and 515 (81.3%) were negative. The bacteria and fungi isolated at the high-est rate in SARS-CoV-2 positive patients were methicillin-resistant coagulase negative staphylococci (MR-CoNS) (21.5%), Escherichia coli (12.4%), Klebsiella pneumoniae (12.4%), Candida albicans (1.65%) and Candida glabrata complex (1.65%); while in negative patients, E. coli (21.3%), MR-CoNS (13.5%), K. pneumoniae (12.05%), C. albicans (2.1%), Candida parapsilosis (1.1%) and Candida tropicalis (0.9%). The fact that the most common isolate was MR-CoNS in SARS-CoV-2 positive patients (p = 0.028); the detection of Acinetobacter baumannii was more frequent (p = 0.001) and the isolation of carbapenem-resistant K. pneumoniae was at a higher rate than in SARS-CoV-2 negative patients; also, the increase in multidrug-resistant strains indicate that healthcare-associated infec-tions should not be disregarded while focusing on the outbreak.

Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium are the three most commonly reported sexually transmitted bacteria. The present study aimed to investigate the presence of C. trachomatis, N. gonorrhoeae, and M. genitalium in urogenital samples collected from 18–68-year-old Turkish patients who were admitted to the hospital with various urogenital symptoms. A total of 360 patients with symptoms of STD were included in the study. Following DNA extraction by QIAamp Mini Kit, the presence of C. trachomatis, N. gonorrhoeae, and M. genitalium were investigated using multiplex real-time PCR. Causative organisms were identified in 68 (18.9%) of 360 patients. C. trachomatis, N. gonorrhoeae, and M. genitalium were detected in 40 (11.1%), 14 (3.9%), and 28 (7.8%) of the patients, respectively. Patients 21–30 years of age represented more than one-third (37.8%) of positive patients. Of all patients, dual infections of C. trachomatis–M. genitalium, N. gonorrhoeae–C. trachomatis, N. gonorrhoeae–M. genitalium, and triple infection of C. trachomatis–N. gonorrhoeae–M. genitalium were determined in 1.6% (6/360), 1.3% (5/360), 0.2% (1/360), and 0.2% (1/360) of the patients, respectively. In CT-, NG-, and MG-positive patients, different STI agents were also found such as HIV, HBV, HPV, HSV2, T. pallidum, and T. vaginalis. In conclusion, among C. trachomatis, N. gonorrhoeae, and M. genitalium, CT was the most frequently detected bacterial cause of STDs in our hospital at Istanbul. Co-infections, which comprise more than one-fifth of the cases, should not be underestimated. Regular screening and following up of STD agents using multiplex real-time PCR-based diagnostic methods enabling the immediate detection of co-infections are essential for the treatment and primary prevention of STDs.

OBJECTIVE: S79Y and S79F mutations in ParC at the fluoroquinolone binding site confer resistance to quinolones in Streptococcus pneumoniae. The aim of this study was to perform bioinformatics analysis of wild-type and mutant ParC identified in S. pneumoniae strains.MATERIALS AND METHODS: Homology models were created with Swiss Model, and the UCSF Chimera was used for the analysis and evaluation of the models. Molecular docking studies and protein-ligand interaction analysis were performed using CB-Dock developed by AutoDock Vina and Protein Ligand Interaction Profiler (PLIP), respectively.RESULTS: According to the homology modeling results, changes were observed in the physicochemical properties. Both mutant types showed a decrease in hydrophobicity (S79F: 2.0, S79Y: 0.5 - Kyte-Doolittle) and an increase in regional volume (S79F: 95 & Aring;3, S79Y: 100 & Aring;3). The docking scores for the wild-type, S79F, and S79Y types were 6.3, 4.9, and 5.0, respectively. The decrease in docking scores indicates weaker binding in the mutant types. The results of the PLIP analysis indicate that new bonds were formed, and the bond types changed in both mutant types, while some bonds disappeared.CONCLUSIONS: It is believed that the change in physicochemical properties caused by the mutation altered the conformation of the quinolone binding region and the bond types, numbers, and proximities of the amino acids involved in the interaction with the active substance. The results obtained from the modeling performed in this study with visualization and analysis of possible conformational, hydrophobic, and volumetric changes of only ParC mutations provided data and literature support to elucidate the mechanism. The molecular docking and PLIP results obtained in this study support both the homology modeling results and the fact that S79F and S79Y have been shown to be resistant in the literature.

Amaç: Pseudomonas aeruginosa hastane enfeksiyonlarına neden olması ve antibiyotiklere direnci ile mortalite ve morbiditeyi yüksek oranda etkilemektedir. Bu çalısmada alt solunum yolu örneklerinden izole edilen P.aeruginosa’nın antibiyotik direnç profili incelenmistir. Gereç ve Yöntemler: Haziran 2016-Eylül 2017 tarihleri arasında gelen alt solunum yolu örneklerinin kültürü yapılmış ve bakteri identifikasyonu konvansiyonel yöntemler ile, antibiyotik duyarlılık testi ise European Committee on Antimicrobial Susceptibility Testing önerilerine göre yapılmıştır. Bulgular: Laboratuvarımızda 5.367 alt solunum yolu örneği incelenmiştir. Toplam 185 hastadan (% 70’i Göğüs Hastalıkları, % 2’si Çocuk Yoğun Bakım Ünitesi hastası) 378 (% 7) P.aeruginosa suşu izole edilmistir. En yüksek direnç oranı % 33 ile imipeneme, sonrasında % 25 ile meropeneme ait bulunmuştur. Tartışma ve sonuç: Ülkemizde yapılan çalısmalar incelendiginde izole edilen P.aeruginosa direnç oranlarına ait farklı veriler olduğu görülmüstür. Buna çalışmaların planlanmasındaki farklılıklar, antibiyotik kullanım politikaları ve tekrar eden hasta örneklerinin istatistiksel verilerden çıkarılamaması gibi durumların neden olduğu düsünülmektedir. Ülkemizde yayınlanan bir meta-analiz çalışmasında son 11 yılda gözlenen P.aeruginosa direnç profili incelenmis, antibiyotiklere direncin azalmakta olduğuna dikkat çekilmistir. Bu bilgiler gözönünde bulunduruldugunda bu çalısmada karbapenemler hariç tüm antibiyotik gruplarında ülke genelinde direnç oranlarının geçmis yıllara kıyasla daha düsük düzeyde oldugu görülmüstür. Karbapenem grubunda mevcut direnç artısı ve diğer gruplarda olan azalmaların daha iyi ortaya konulabilmesi ve genellenebilmesi için ülke genelinde genis kapsamlı, çalışmaların yaplmasının yararlı olacağı düşünülmektedir.

Staphylococcus aureus, methicillin resistance, pyoderma, nasal carriage, prevalence.