[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.

Bacterial Pathogens: Potential Source For Antimicrobial Peptides.

As more antibiotics become ineffective due to drug-resistant bacteria, alternative therapies for infections must be prioritized. While pathogenic bacteria are a major threat, they also supply a massive reservoir of potential drugs for treating a wide range of illnesses. The concerning emergence of antimicrobial resistance and the rapidly dwindling therapeutic pipeline need the quick discovery and development of new antibiotics. Despite their great promise for natural product medicine development, pathogenic microorganisms have remained mostly unexplored and understudied. We review the antibacterial activity of specialized metabolites derived from pathogenic bacteria, emphasizing those presently in pre-clinical studies or with promise for medication development. Several atypical biosynthetic pathways are outlined, together with the crucial functions. We also discuss the mechanism of action and antibacterial activities of the antibiotics under consideration. Pathogenic bacteria as a rich source of antibiotics, along with recent advances in genomics and natural product research methods, may usher in a new golden age of antibiotic discovery.

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.

[The Mutations on embA, embB and embC Gene Region in Ethambutol-Resistant and Susceptible Clinical Mycobacterium tuberculosis Complex Isolates]. / Etambutole Dirençli ve Duyarli Mycobacterium tuberculosis Kompleksi Klinik Izolatlarinda embA, embB ve embC Gen Bölgesi Mutasyonlari.

Ethambutol (EMB) is one of the first-line drugs used in the standard combination therapy for tuberculosis (TB) caused by Mycobacterium tuberculosis complex (MTC), and resistance to drugs that play a key role in treatment is increasing worldwide. Mutations in the embCAB operon that have been confirmed to be associated with resistance are responsible for EMB resistance. In this study, it was aimed to determine the frequency and patterns of mutations in embA, embB and embC gene regions in clinical MTC isolates found to be phenotypically resistant and susceptible to EMB. A total of 64 MTC isolates, 44 of resistant to EMB and 20 of susceptible to EMB, isoniazid, rifampicin, and streptomycin by conventional phenotypic drug susceptibility test, were included in the study. Following the DNA isolation, embA, embB and embC gene regions associated with EMB resistance were amplified with specific primer sequences. The PCR products were cycle sequenced using the Bigdye Terminator v3.1 Cycle Sequencing kit (Applied Biosystems, USA) and electrophoretically separated on the ABI PRISM 3130XL Genetic Analyzer (Applied Biosystems, USA). Mutated gene regions were identified by aligning sequence analysis data in multiple sequence analysis programs. In the study, genomic mutations in the embCAB operon were detected in 68.2% (30/44) of the EMB resistant isolates. Mutations in the embB gene region were detected in 66% (29/44) of the resistant isolates, 76% (22/29) of these mutations were at codon 306 and the most common mutation patterns in this codon were determined as ATG→GTG (M306V; 58.6%; 17/29), ATG→ATA, ATC or ATT (M306I; 17.2%; 5/29). Other mutations in the embB gene region were determined as Y334H (3.4%; 1/29), D354A (6.9%; 2/29), E378A (3.4%; 1/29), G406C (3.4%; 1/29), M423I (3.4%; 1/29) and E521A (3.4%; 1/29). Of the 44 EMB-resistant isolates, mutations were detected in one (2.3%) of the isolate in the embA gene region (L330L) and in two (4.5%) of the isolates in the embC gene region (T270I in one isolate and T270I and E305E in the other isolate). Of the phenotypically EMB susceptible isolates, mutation was detected in only one (5%) of the isolates in the embA gene region (E180G). In our study, it was determined that mutations frequently occur in codon 306 of the embB gene in EMB-resistant MTC isolates and this mutation has a potential role in the development of EMB resistance. However, it was concluded that the absence of mutations does not exclude phenotypic EMB resistance. Our results will shed light on the molecular epidemiology of embCAB operon mutations that cause EMB resistance in our country.

The Distribution of Cytotoxic Necrotizing Factors (CNF-1, CNF-2, CNF-3) and Cytolethal Distending Toxins (CDT-1, CDT-2, CDT-3, CDT-4) in Escherichia coli Isolates Isolated from Extraintestinal Infections and the Determination of their Phylogenetic Relationship by PFGE.

Backgrounds: Diagnostic markers of extraintestinal infection in Escherichia coli (E. coli) remain unclear in the literature. Extraintestinal pathogenic E. coli (ExPEC) is differentiated from other E. coli isolates in terms of virulence factors, such as host cell adhesion, invasion, cytotoxic necrotizing factor (CNF (cnf1-cnf3)) and cytolethal distending toxin (CDT (cdt1-cdt4) that are responsible for cell death. We aimed to investigate the frequency of CNF-CDT and the relationship between the clinical diagnosis and genotypes in E. coli isolates with different clinical origins. Methods: A total of 646 E. coli isolates (obtained from 645 patients) isolated from different infection sites other than the intestine were evaluated in aspects of the CNF, CDT virulence genes, phylogenetic grouping, and phylogenetic relationship by using PCR and PFGE. Results: At least one virulence gene was present in 156 (24%) of the 646 ExPEC isolates. We detected cnf1, cnf2, and cnf3, in 78, 12, and 20 ExPEC isolates, respectively. Also, cdt1, cdt2, cdt3, and cdt4 genes were present in 20, 4, 4, and 4 isolates, respectively. Some isolates harbored more than one gene, being cnf1-cnf3 (n = 6), cnf1-cdt1 (n = 4), and cdt1-cdt4 (n = 4). These 156 isolates were distributed into 106 large clusters by PFGE. Virulent ExPEC is primarily related to groups B2 (60%) and D (32%). Conclusion: To our knowledge, this study demonstrated the presence of cnf2, cnf3, cdt1, cdt2, cdt3, and cdt4 genes for the first time in the literature for Turkey. The widespread presence of the CNF gene in E. coli helps distinguish ExPEC from commensal isolates.

Distribution of emm, superantigen and other virulence genotypes and detection of phylogenetic relationships in group A streptococcal isolates.

Group A streptococci are important pathogens with various virulence factors, such as M protein, superantigens, hemolysins, deoxyribonuclease, and proteases. The aims of this study are to investigate the detection of emm genotypes and other virulence genes, such as SAgs, DNase, protease, antibiotic resistance, and phylogenetic relationships in GAS strains isolated from clinical samples.Test strains were obtained from Çukurova University Balcali Hospital and regional hospitals in Adana province. The M proteins were detected by sequence analysis of emm genes. SAgs and other virulence gene profiles were determined using the Multiplex-PCR method. The antibiotic susceptibility of the isolates was performed by the disc diffusion method and evaluated according to CLSI criteria. The PFGE method was used to determine the clonal relationship between the strains.The emm gene was positive in 86 isolates. The most common emm genotypes were emm28 (22%), emm1 (18.6%), emm12 (13.9%), and emm3 (11.6%). Also, the most common virulence genes were speG (58.1%), speC (56.9%), sdaB (53.4%), and mac (53.4%). The rates of resistance to erythromycin, clindamycin, levofloxacin, ciprofloxacin and telithromycin were 19.8%, 16.3%, 4.7%, 3.5%, and 3.5%, respectively.As a result, additional regional studies on the detection and prevalence of GAS virulence factors in Turkey are required. We believe that this study will provide valuable information for epidemiological studies on emm sequences, Sags, and other virulence factors of Streptococcus pyogenes in Turkey.

Overexpression of Efflux Pumps AcrAB and OqxAB Contributes to Ciprofloxacin Resistance in Clinical Isolates of K. pneumonia.

BACKGROUND: Infection caused by multidrug-resistant K. pneumoniae is regarded as a severe public health concern worldwide, with most countries reporting an increase in fatality rates over time. Efflux pumps are significant determinants of acquired and/or intrinsic resistance in K. pneumoniae. OBJECTIVES: Our aim is to explore efflux-mediated resistance mechanisms in K. pneumoniae by using quantitative real-time PCR in order to evaluate the expression of efflux pump genes (acrA, acrB, oqxA, and oqxB) and pump regulators (marA, soxS, and rarA). METHODS: Efflux pump inhibitor CCCP reduced MIC values of ciprofloxacin by 2 to 64-fold in 43/46 (93%) of MDR-K. pneumoniae isolates. RESULTS: Compared to the control strain (untreated one), our results demonstrated that acrA, acrB, oqxA, oqxB, marA, soxS, and rarA were overexpressed in 29 (63%), 24 (52%), 29 (63%), 24 (52%), 17 (37%), 16 (35%), and 16 (35%) of K. pneumoniae isolates, respectively. Additionally, a positive correlation was established between the expressions of acrAB and marA (r = 0.50, r = 0.45, respectively) and oqxAB and rarA (r = 0.462912, r = 0.519354, respectively). CONCLUSION: Ciprofloxacin resistance was caused by overexpression of the efflux pump genes acrAB and oqxAB, as well as the transcriptional regulators marA, soxS, and rarA in clinical isolates of K. pneumonia.

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.

Polysaccharides to Combat Viruses (COVID-19) and Microbes: New updates.

COVID-19, which is speedily distributed across the world and presents a significant challenge to public health, is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Following MERS coronavirus (MERS-CoV) and SARS, this is the third severe coronavirus outbreak in less than 20 years. To date, there are no exact agents and vaccines available for the treatment of COVID-19 that are clinically successful. Antimicrobial medications are effective in controlling infectious diseases. However, the extensive use of antibiotics makes microbes more resistant to drugs and demands novel bioactive agents' development. Polysaccharides are currently commonly used in the biomedical and pharmaceutical industries for their remarkable applications. Polysaccharides appear to have a wide range of anti-virus (anti-coronavirus) and antimicrobial applications. Polysaccharides are able to induce bacterial cell membrane disruption as they demonstrate potency in binding onto the surfaces of microbial cells. Here, the antiviral mechanisms of such polysaccharides and their success in the application of antiviral infections are reviewed. Additionally, this report provides a summary of current advancements of well-recognized polysaccharides as antimicrobial and anti-biofilm agents.

Evaluation of Antibiotic Resistance and adeABC, adeR, adeS Efflux Pump Genes among Foodborne and Clinical Acinetobacter spp. in Türkiye.

Background: The adeABC efflux pump has a crucial role in the resistance of Acinetobacter baumannii strains to antimicrobial agents; it is encoded by adeABC, adeR, adeS genes. We evaluated antibiotic resistance, efflux pump genes, clonal relationships, and analyzed a probable correlation that can exist between antibiotic resistance and the aforementioned genes. Methods: We conducted this study on 27 food-originated and 50 human clinical Acinetobacter spp. in Southern Türkiye. MALDI-TOF system and disc diffusion/agar dilution (colistin) methods were used for the identification and antibiotic susceptibility. The efflux pump genes and genetic relatedness of the two groups were investigated by (PCR) and (PFGE) methods. Results: Foodborne A. dijkshoorniae strain was multidrug- resistant (MDR), and none of them resistant to colistin. Most of the clinical isolates (92%) were Extensive-Drug Resistant (XDR); highest resistant to ceftazidime, piperacillin-tazobactam, and imipenem (47, 94%), and were lowest to colistin (7, 14%), respectively. adeABC, and adeR, adeS genes were (23, 85.2%), (9, 33.3%), (27, 100%) and (10, 37.3%), (18, 66.7%) in foodborne strains respectively. These rates were (43, 86%), (48, 96%), (50, 100%), and (34, 68%), (48, 96.7%) in clinical strains respectively. A positive correlation existed between adeA gene positivity and piperacillintazobactam, ceftazidime, gentamycin, imipenem (P=0.048), amikacin (P=0.007) and trimethoprimsulfamethoxazole (P=0.029) resistance in clinical strains. A positive correlation of trimethoprimsulfamethoxazole resistance and adeS gene positivity was seen in foodborne strains (P=0.018). Conclusion: Multiple-efflux pump genes rise in parallel to multidrug-resistance in clinical isolates, while susceptible to diverse antibiotics; food may be a potential provenance for the dissemination of adeABC, adeR and adeS genes.

Toxoplasma gondii seroprevalence among tuberculosis patients: A systematic review and meta-analysis.

Toxoplasma gondii and Mycobacterium tuberculosis are intracellular pathogens, both infecting a substantial proportion of human population. We conducted a systematic review and meta-analysis to estimate the pooled T. gondii seroprevalence in tuberculosis patients. Three international databases were systematically searched for literature on prevalence of T. gondii in tuberculosis patients. A total of 1389 documents were identified, and eight papers were eligible to be included in the systematic review and meta-analysis. Geographical data gaps were evident, as no studies were identified from many countries where both infections are important. The pooled seroprevalence of IgG, IgM, and both IgG and IgM antibodies against T. gondii in tuberculosis patients were estimated to be 35.9% (95% confidence interval [CI], 19.3-56.7%), 35.0% (95% CI, 3.0-90.3%), and 13.4% (95% CI, 2.4-49.0%), respectively. In the included case-control studies, the pooled T. gondii seroprevalence (proportion anti- T. gondii IgG antibody positive) was higher in tuberculosis patients than in their controls, with an odds ratio by random effects model of 1.63 (95% CI, 1.28-2.08). The results of our work suggest an association between T. gondii seropositivity and being a tuberculosis patient, which should however be interpreted with caution because the timeline of the infections and the disease process are not accounted for. Our work showed that T. gondii seropositivity, indicating chronic infection with the zoonotic parasite, was relatively common among tuberculosis patients.

Efflux pump inhibitors: new updates.

The discovery of antibiotics ought to have ended the issue of bacterial infections, but this was not the case as it has led to the evolution of various mechanisms of bacterial resistance against various antibiotics. The efflux pump remains one of the mechanisms through which organisms develop resistance against antibiotics; this is because organisms can extrude most of the clinically relevant antibiotics from the interior cell environment to the exterior environment via the efflux pumps. Efflux pumps are thought to contribute significantly to biofilm formation as highlighted by various studies. Therefore, the inhibition of these efflux pumps can be a potential way of improving the activity of antibiotics, particularly now that the discovery of novel antibiotics is becoming tedious. Efflux pump inhibitors (EPIs) are molecules that can inhibit efflux pumps; they have been considered potential therapeutic agents for rejuvenating the activity of antibiotics that have already lost their activity against bacteria. However, studies are yet to determine the specific substrates for such pumps; the effect of altered efflux activity of these pumps on biofilm formation is still being investigated. A clear knowledge of the involvement of efflux pumps in biofilm development could aid in developing new agents that can interfere with their function and help to prevent biofilms formation; thereby, improving the outcome of treatment strategies. This review focuses on the novel update of EPIs and discusses the evidence of the roles of efflux pumps in biofilm formation; the potential approaches towards overcoming the increasing problem of biofilm-based infections are also discussed.

An Overview of the Activities of Cefiderocol Against Sensitive and Multidrug- Resistant (MDR) Bacteria.

The need for new therapeutics and drug delivery systems has become necessary owing to the public health concern associated with the emergence of multidrug-resistant microorganisms. Among the newly discovered therapeutic agents is cefiderocol, which was discovered by Shionogi Company, Japan as an injectable siderophore cephalosporin. Just like the other ß-lactam antibiotics, cefiderocol exhibits antibacterial activity via cell wall synthesis inhibition, especially in Gram negative bacteria (GNB); it binds to the penicillin-binding proteins, but its unique attribute is that it crosses the periplasmic space of bacteria owing to its siderophore-like attribute; it also resists the activity of ß-lactamases. Among all the synthesized compounds with the modified C-7 side chain, cefiderocol (3) presented the best and well-balanced activity against multi-drug resistant (MDR) Gram negative bacteria, including those that are resistant to carbapenem. In this article, an overview of the recent studies on cefiderocol was presented.

Genetic evaluation of Mycobacteriumbovis isolates with MIRU-VNTR and spoligotyping

Background/aim: Determining the epidemiological characteristics of M. bovis strains isolated from human and animal tuberculosis cases will assist in taking more appropriate and effective control measures in controlling tuberculosis originating from animal Materials and methods: In this study, 32 M. bovis isolates of animal origin and 10 of human origin were isolated and identified in the Çukurova region between March 2011 and June 2012. The 12-locus MIRU-VNTR and spoligotyping methods were used. Results: Six different patterns were determined by spoligotyping and 10 by MIRU-VNTR. When both methods were used together, the number of patterns was found to be 28; MIRU4, MIRU26, MIRU31, and MIRU40 had the highest locus discrimination powers by MIRU-VNTR. The isolates concentrated in the SB0120 pattern at the rate of 42.85% in spoligotyping. By the same method, it was seen that 7 isolates were M bovis ssp. caprae pattern and 2 human isolates were M. bovis BCG pattern. Nevertheless, spoligotyping and MIRU-VNTR patterns showed that 5 M. bovis isolates of human origin were 100% compatible with isolates originating from cattle. Conclusion: In this study, we determined that the use of spoligotyping and MIRU-VNTR methods together was found to be more sensitive in the epidemiological analysis of M. bovis isolates.

A Glance on the Role of Bacterial Siderophore from the Perspectives of Medical and Biotechnological Approaches.

Iron, which is described as the most basic component found in nature, is hard to be assimilated by microorganisms. It has become increasingly complicated to obtain iron from nature as iron (II) in the presence of oxygen oxidized to press (III) oxide and hydroxide, becoming unsolvable at neutral pH. Microorganisms appeared to produce organic molecules known as siderophores in order to overcome this condition. Siderophore's essential function is to connect with iron (II) and make it dissolvable and enable cell absorption. These siderophores, apart from iron particles, have the ability to chelate various other metal particles that have collocated away to focus the use of siderophores on wound care items. There is a severe clash between the host and the bacterial pathogens during infection. By producing siderophores, small ferric iron-binding molecules, microorganisms obtain iron. In response, host immune cells produce lipocalin 2 to prevent bacterial reuptake of siderophores loaded with iron. Some bacteria are thought to produce lipocalin 2-resistant siderophores to counter this risk. The aim of this article is to discuss the recently described roles and applications of bacterial siderophore.

Differential Expression of Resistant and Efflux Pump Genes in MDR-TB Isolates.

BACKGROUND: Numerous investigations demonstrate efflux as a worldwide bacterial mode of action which contributes to the resistance of drugs. The activity of antibiotics, which subjects to efflux, can be improved by the combined usage of efflux inhibitors. However, the efflux role to the overall levels of antibiotic resistance of clinical M. tuberculosis isolates is inadequately comprehended and is still disregarded by many. METHODS: Here, we assessed the contribution of resistant genes associated with isoniazid (INH) and rifampin (R) resistance to the levels of drug resistance in the (27) clinical isolates of MDR-TB. Additionally, the role of the resistance for six putative drug efflux pump genes to the antibiotics was investigated. The level of katG expression was down-regulated in 24/27 (88.88%) of MDR-TB isolates. Of the 27 MDR-TB isolates, inhA, oxyR-ahpC, and rpoB showed either overexpression or up-regulation in 8 (29.62%), 4 (14.81 %), and 24 (88.88%), respectively. Moreover, the efflux pump genes drrA, drrB, efpA, Rv2459, Rv1634, and Rv1250 were overexpressed under INH/RIF plus fresh pomegranate juice (FPJ) stress signifying the efflux pumps contribution to the overall levels of the resistance of MDR-TB isolates. CONCLUSION: These results displayed that the levels of drug resistance of MDR-TB clinical isolates are due to combination among drug efflux pump and the presence of mutations in target genes, a truth which is often ignored by the specialists of tuberculosis in favour of the almost undoubted significance of drug target- gene mutations for the resistance in M. tuberculosis.

[Detection and Molecular Analysis of Moxifloxacin MIC Values of Mycobacterium tuberculosis Strains Isolated from Clinical Specimens]. / Klinik Örneklerden Elde Edilen Mycobacterium tuberculosis Izolatlarinin Moksifloksasin MIK Degerlerinin Tespiti ve Moleküler Analizi.

Tuberculosis (TB) is a chronic, granulomatous and necrotizing disease caused by microorganisms belonging to the Mycobacterium tuberculosis complex group. In 2017, 6.4 million new TB cases have been reported according to the World Health Organization 2018 Global Tuberculosis Report. TB remains among the major health problems of our time due to the increasing drug resistance problem and the difficulties in definitive diagnosis in recent years. It is stated by clinicians that intensive use of quinolone group drugs with oral form in simple indications such as respiratory or urinary tract infections may lead to resistance and this may result in treatment failures. The aim of this study was to determine the moxifloxacin susceptibility of M.tuberculosis isolates obtained from clinical specimens by phenotypical methods, to determine the resistance rates of moxifloxacin and to investigate the relationship between phenotypical resistance and mutations in the gyrA gene. A hundred (n= 100) consecutive non-multidrug resistant and 37 non-consecutive multidrug resistant M.tuberculosis strains isolated from the clinical specimens of patients with pulmonary tuberculosis were included in the study. The moxifloxacin susceptibility of the isolates was determined by using Löwenstein-Jensen medium and their epidemiological properties were investigated and also mutations detected by gyrA region were compared with drug susceptibility rates. Of the 137 isolates tested for phenotypical susceptibility, 25 (18.2%) were found to be resistant to moxifloxacin. Resistance rate among non-multidrug resistant and multidrug resistant isolates were determined as 17% and 21.6%, respectively. According to the results of the sequencing analysis, of the gyrA regions of all the isolates included in the study, a single base mutation was found in a total of six samples. The location positions of the mutations were determined as D94Y, D94G, A90V, G88A and among two strains as D89N. Two of the isolates with mutations were found to be phenotypically susceptible to moxifloxacin. In our study, it was found that moxifloxacin resistance in M.tuberculosis isolates was higher than similar studies and it was found that different mechanisms may be responsible for the existing resistance other than the mutations in the gyrA gene. It was concluded that the data obtained from the study should be shared with all clinicians in the country due to the possibility of resistance development to this group of drugs in a short time and considering this drug will have an important role in the treatment of TB, it should be used more limited in non-specific indications. Further studies using larger case groups and isolates are needed for the continuation of the research.

Evaluation of Polyphenolic Profile and Antibacterial Activity of Pomegranate Juice in Combination with Rifampin (R) against MDR-TB Clinical Isolates.

BACKGROUND: The global rise of multi-drug resistant M. tuberculosis demands unconventional treatment to enhance the efficiency of current drugs. Punica granatum, which is known as pomegranate, is considered as a member of the Punicaceae family. Pomegranate, which is broadly documented for its activity against a wide spectrum of bacterial pathogens, deserves further scrutiny in this respect. METHODS: Within this scope, this study investigated the effect of fresh pomegranate juice (FPJ) on the antibacterial activity of anti-tuberculosis drugs (Rifampin (R) and Isoniazid (INH)) against MDR-TB clinical isolates. The drug resistance profiles in M. tuberculosis clinical isolates were determined by susceptibility test using BACTEC MGIT 960 system. Four concentrations of fresh pomegranate juice (FPJ) (5%, 10%, 15%, and 20%) were evaluated in combination with R and INH at a dose range of (1.0 µg/ml) and (0.1 µg/ml), respectively against the MDR-TB isolates by the BACTEC MGIT 960 system. Moreover, this study scrutinized individual phenolic compounds of FPJ by using highperformance liquid chromatography (HPLC). The total polyphenols (TP), total flavonoid (TF), total anthocyanins content (TAC), and the antioxidant capacity were also assessed in FPJ. RESULTS: Synergistic effects were observed between R and INH with FPJ against all tested strains. However, combination therapy of rifampin was more effective than isoniazid one. Therefore, the combination of R and FPJ has been used against (27) MDR-TB clinical isolates. 5% of FPJ plus R (1.0 µg/ml) were found to suppress the growth of one isolates for first group (INH and R resistant). However, 5% of FPJ demonstrated no synergistic impact with R for second (SM, R and INH resistant) and third group (INH, EMB, R and SM resistant). Moreover, 10% of FPJ and R (1.0 µg/ml) inhibited the bacterial growth of three isolates of first group and two isolates and one isolate for second and third group, respectively. Remarkably, 15% of FPJ plus R (1.0 µg/ml) appeared to inhibit the growth of MDR-TB isolates for all tested groups indicating a strong synergistic effect. Regarding H37RV, the complete inhibition of the bacterial growth was found to occur at 15% and 20% concentrations of FPJ only. Minimum inhibitory concentration (MIC) of FPJ ranged from (4% to13%) for first group and from (10% to15%) for second and third group. Thus, FPJ at 15% inhibited 100% of bacteria for all tested isolates (MIC100% =15%). Phenolic compounds identified in FPJ were gallic acid, benzoic acid, syringic, folic acid, pelargonidin, naringin+ellagic acid, naringenin, chlorogenic acid, caffeic acid, catechin, myricetin, kaempferol, quercetin, cyanidin-3-glycoside, p-cummaric acid, ferulic acid, and rutin. Total phenolic (TP), total flavonoid (TF), and total anthocyanin (TA) content were 841.5 mg/L, 638.73 mg RE/L, and 47.43 mg/L, accordingly. CONCLUSION: Overall, FPJ displayed synergistic effect with R against MDR-TB clinical isolates due to its high content of polyphenol and antioxidant capability.

Does the Development of Vaccines Advance Solutions for Tuberculosis?

BACKGROUND: Mycobacterium tuberculosis (Mtb) is considered as one of the most efficacious human pathogens. The global mortality rate of TB stands at approximately 2 million, while about 8 to 10 million active new cases are documented yearly. It is, therefore, a priority to develop vaccines that will prevent active TB. The vaccines currently used for the management of TB can only proffer a certain level of protection against meningitis, TB, and other forms of disseminated TB in children; however, their effectiveness against pulmonary TB varies and cannot provide life-long protective immunity. Based on these reasons, more efforts are channeled towards the development of new TB vaccines. During the development of TB vaccines, a major challenge has always been the lack of diversity in both the antigens contained in TB vaccines and the immune responses of the TB sufferers. Current efforts are channeled on widening both the range of antigens selection and the range of immune response elicited by the vaccines. The past two decades witnessed a significant progress in the development of TB vaccines; some of the discovered TB vaccines have recently even completed the third phase (phase III) of a clinical trial. OBJECTIVE: The objectives of this article are to discuss the recent progress in the development of new vaccines against TB; to provide an insight on the mechanism of vaccine-mediated specific immune response stimulation, and to debate on the interaction between vaccines and global interventions to end TB.

Molecular characterization of methicillin-resistant Staphylococcus aureus strains by spa typing and pulsed field gel electrophoresis methods.

BACKGROUND: Rapid detection of sources and transmission routes by molecular methods provides key data for risk management of methicillin-resistant Staphylococcus aureus-induced infections acquired in both the community and hospitals. This study aimed to determine the clonal relationship of methicillin-resistant S. aureus strains isolated from our hospital by pulsed-field gel electrophoresis (PFGE) and Staphylococcal protein A (spa) typing methods and to identify the predominant clones in Cukurova Region, Turkey. RESULTS: All isolates analyzed by PFGE were distributed among 11 clusters. Clusters A (n = 19) and B (n = 27) were 84.1% similar and accounted for 61% of all samples. All isolates were distributed among 18 spa types, with the most common type being t030 with 31 isolates (41.3%), followed by t223 with nine isolates (12%) and t127 with seven isolates (9.3%). CONCLUSIONS: We found that t030 was the most common spa type in the area where the study was conducted, as also previously shown in studies undertaken in Turkey. However, the rate of t030 in our study was below the rates reported in the literature. We also detected some rare or sporadic spa types like t127, which has not been previously defined in our country. We consider that the spa typing and PFGE methods are useful for research on clonal relations in monitoring the changing prevalent clones in specific regions.