[Determination of Capsule Types, Antibiotic Resistance Profiles and Phylogenetic Relationships of Group B Streptococcus Isolates Isolated from Patients Followed in Various Clinics and Polyclinics]. / Çesitli Klinik ve Polikliniklerde Takip Edilen Hastalardan Izole Edilen Grup B Streptokok Izolatlarinin Kapsül Tiplerinin Belirlenmesi, Antibiyotik Direnç Profilleri ve Filogenetik Iliskilerinin Arastirilmasi.

Group B streptococci (GBS) are microorganisms that cause various systemic infections. In this study, it was aimed to investigate the capsule serotypes, antibiotic resistance and phylogenetic similarity relationship between GBS isolates. One hundred and ten GBS isolates isolated from female patients who admitted to Adana City Hospital with various complaints were included in the study. Kirby-Bauer disc diffusion method was used for the antibiotic resistance patterns and evaluated with CLSI criteria. The genes ermB, ermTR, mefA for erythromycin resistance and linB genes for clindamycin resistance were investigated by multiplex PCR method. Multiplex PCR method was used for GBS capsule serotyping. Similarity relationship between the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) method. As a result of the study; all strains were found to be sensitive to penicillin and vancomycin. Erythromycin, clindamycin ofloxacin, and ceftriaxone resistance rates were observed as 60%, 11.8%, 6.4%, and 4.5%, respectively. The mefA gene was not found while 53% and 47% of the erythromycin-resistant isolates carried ermTR and ermB genes, respectively. The linB gene was not found in clindamycin-resistant GBS isolates. The capsule serotype distributions of GBSs were found as, Ib 42.7%, Ia 35.5%, III 10%, II 8.2%, and V 3.6%, respectively. In the analysis of the similarity relationships between GBS isolates with the PFGE method, no significant relationship was found. In conclusion, it was thought that more studies should be conducted to show the prevalence of GBS capsule serotypes and patterns of antibiotic resistance.

The investigation of community-acquired and nosocomial respiratory syncytial virus and other viral respiratory tract infections in children.

Although respiratory viruses are known as the major causes of community-acquired respiratory tract infections all over the world, they can also cause serious nosocomial respiratory infections and hospital outbreaks. The aim of this study is to investigate the incidence of community-acquired and nosocomial RSV and other viral respiratory tract infections in children hospitalized at the Pediatric Intensive Care Unit of Cukurova University Faculty of Medicine. Nasopharyngeal swab samples were taken from 100 children aged 0-16 years with suspected community-acquired (60) and nosocomial (40) respiratory tract infections from September 2018 to June 2021. The Multiplex real-time PCR test was used for the diagnosis of respiratory viruses. Of children with community-acquired respiratory tract infections, 65% (39/60) were positive for at least one virus and the rate of coinfection in this group was 35.9% (14/39). In children with nosocomial respiratory tract infection, positivity was detected to be 62.5% (25/40) and the coinfection rate was 40% (10/25). The most predominant virus in community-acquired respiratory tract infections was influenza A virus (25%), followed by ADV (18.3%), hBoV (15%), RSV (11.7%), and RhV (10%). In nosocomial viral respiratory tract infections, the most common virus was RSV (20%), followed by influenza A virus (12.5%), RhV (12.5%), ADV (12.5%), hMpV (10%), and hBoV (10%). Early diagnosis of respiratory viral infections with real-time PCR test is important in terms of reducing morbidity and mortality, applying control methods to prevent the spread of nosocomial viruses, shortening the hospitalization period, preventing the use of unnecessary antibiotics, and giving appropriate antiviral treatment.

Meropenem in combination with baicalein exhibits synergism against extensively drug resistant and pan-drug-resistant Acinetobacter baumannii clinical isolates in vitro.

Several studies have demonstrated that the effectiveness of carbapenems against drug-resistant Acinetobacter baumannii infections has been decreasing. Combination therapy with two or more drugs is currently under investigation to overcome the emerging resistance against carbapenems. In this study, we tested the possible synergistic interactions of a potent antibacterial flavonoid, baicalein, with meropenem to illustrate this duo's antibacterial and antibiofilm effects on 15 extensively drug resistant or pan-drug-resistant (XDR/PDR) A. baumannii clinical isolates in vitro. Isolates included in the study were identified with MALDI-TOF MS, and antibiotic resistance patterns were studied according to EUCAST protocols. Carbapenem resistance was confirmed with the modified Hodge test, and resistance genes were also analyzed with genotypical methods. Then, checkerboard and time-kill assays were performed to analyze antibacterial synergism. Additionally, a biofilm inhibition assay was performed for screening the antibiofilm activity. To provide structural and mechanistic insights into baicalein action, protein-ligand docking, and interaction profiling calculations were conducted. Our study shed light on the remarkable potential of the baicalein-meropenem combination, since either synergistic or additive antibacterial activity was observed against every XDR/PDR A. baumannii strain in question. Furthermore, the baicalein-meropenem combination displayed significantly better antibiofilm activity in contrast to standalone use. In silico studies predicted that these positive effects arose from inhibition by baicalein of A. baumannii beta-lactamases and/or penicillin-binding proteins. Overall, our findings highlight the prospective potential benefits of baicalein in combination with meropenem for the treatment of carbapenem-resistant A. baumannii infections.

[Relationship of Hypervirulent Capsular Genotypes of Klebsiella pneumoniae with Antibiotic Susceptibility and Beta-Lactamase Genes]. / Klebsiella pneumoniae Hipervirülan Kapsül Genotiplerinin Antibiyotik Duyarliligi ve Beta-Laktamaz Genleri ile Iliskisi.

Klebsiella pneumoniae which is a causative agent of nosocomial infections, is protected from phagocytosis and the lethal effect of serum bactericidal proteins owing to its capsular polysaccharides (CPS). The important leading problem in treating infections caused by this bacterium that successfully develops antimicrobial resistance, especially via mobile genetic elements, is that it acquires beta-lactamase genes, which are responsible for the resistance against beta-lactam antibiotics. Due to the increase in studies targeting capsular polysaccharides in developing strategies for vaccination and treatment, we aimed to investigate the possible relationship of the capsular genotypes of K.pneumoniae isolates obtained from various clinical specimens with antibiotic susceptibility and beta-lactamase genes. In K.pneumoniae clinical isolates; K1, K2, K5, K20, K54 and K57, which are known as hypervirulent capsular types, were investigated by polymerase chain reaction (PCR) method. In isolates whose capsular genotypes were determined, antibiotic susceptibility was examined by Kirby-Bauer disc diffusion method. Colistin resistance was investigated by the broth microdilution method. Carbapenem resistance was confirmed with the carbapenem inactivation test. The beta-lactamase genes blaCTX-M1, blaCTX-M2, blaCTX-M9, blaCTX-M8/25, blaKPC, blaNDM-1, and blaOXA-48-like were investigated by using PCR. Of the 38 K.pneumoniae isolates whose capsular genotypes were determined, 15 (39.5%), 12 (31.6%), seven (18.4%), two (5.3%), one (2.6%) and one (2.6%) were K5-CPS, K2-CPS, K20-CPS, K1-CPS, K54-CPS and K57-CPS genotypes, respectively. blaOXA-48-like, blaNDM-1, and blaCTX-M1 were detected in 68.4, 10.5, and 7.9%, whereas coexistence of blaOXA-48-like with blaNDM-1, and blaOXA-48-like with blaCTX-M1 were determined in 7.9, and 5.3% of the isolates, respectively. The relationship of the blaCTX-M1 gene, detected only in three K20-CPS isolates, was found to be statistically significant with this genotype. In addition, of the blaNDM-1-positive four isolates, three were K5-CPS, and one was K2-CPS, while blaOXA-48-like was similarly detected mostly in K5-CPS and K2-CPS (10 and 9 isolates, respectively). Except for the two isolates that were resistant to colistin, one K1-CPS and the other K5-CPS, the highest resistance was detected against cefotaxime (36/38) and the lowest resistance was detected against gentamicin (23/38) as a result of antibiotic susceptibility tests. The resistance relationship of K5-CPS isolates with amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin and ertapenem and the susceptibility relationship of K20-CPs isolates with amoxicillin/clavulanate, piperacillin/tazobactam, imipenem, tetracycline and trimethoprim/sulfamethoxazole were found as statistically significant. Our study is the first to investigate the relationship between K.pneumoniae capsular genotypes and beta-lactamase genes in Turkey. As a result, it is believed that this research will contribute to the determination of vaccine and treatment options by providing data to wider and regional studies that will examine other capsule genotypes and antibiotic resistance genes to clarify the importance of the capsule in virulence.

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.