Sensitive and selective determination of upadacitinib using a custom-designed electrochemical sensor based on ZnO nanoparticle-assisted molecularly imprinted polymer.

Upadacitinib (UPA) is a selective and reversible oral Janus kinase (JAK) 1 inhibitor and is of great importance in treating inflammatory bowel disease (Zheng et al., Int Immunopharmacol 126:111229, 2024; Foy et al., JAAD Case Rep 42:20-22, 2023). Although there are limitations to the effectiveness of UPA, it has received positive responses in clinical trials and is approved for the treatment of atopy dermatitis (AD) (Li et al., Int Immunopharmacol 125:111193, 2023). In this study, a nanoparticle-doped molecularly imprinted polymer (MIP)-based electrochemical sensor was developed for sensitive and selective detection of UPA. The developed sensor was designed as a thin film layer using the photopolymerization method on the surface of the prepared nanoparticle-doped polymerization solution glassy carbon electrode (GCE). Various nanoparticles, such as multi-walled carbon nanotube, titanium dioxide, oxide, and zinc oxide (ZnO) nanoparticles, were the most suitable for UPA. Surface characterization of the developed sensor was done by scanning electron microscopy (SEM), and electrochemical characterization was done by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The quantitative analysis of UPA was performed in 5.0 mM [Fe (CN)6]3-/4- solution using the differential pulse voltammetry (DPV) technique. Under optimum conditions, the calibration range was between 0.1 and 1 pM. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 0.005 pM and 0.017 pM, respectively. The sensor's accuracy was proven by performing a recovery study in serum. The sensor's selectivity was also evaluated using common interfering substances such as KNO3, CaCl2, Na2SO4, uric acid, ascorbic acid, dopamine, and paracetamol. According to the results obtained, the performance of the designed sensor was found to be quite sensitive and selective in determining UPA. The developed UPA-ZnO/3-APBA@MIP-GCE sensor showed high sensitivity and selectivity towards UPA. In addition, the selectivity, the most important feature of the MIP-based sensor, was confirmed by imprinting factor (IF) calculations using tofacitinib (TOF) and ruxolitinib (RUX). The sensor's unique selectivity is demonstrated by its successful performance even in the presence of UPA impurities.

Fabrication of a molecularly imprinted polymer-based electrochemical sensor for the selective assay of antipsychotic drug clozapine and performance comparison with LC-MS/MS.

Clozapine (CLO) is an atypical antipsychotic drug indicated for the treatment of schizophrenia. The treatment effectiveness of CLO is better than that of other atypical antipsychotics, and it has the advantage of being able to determine its effectiveness by measuring its concentration in the patient's blood. Thus, sensitive, selective, and accurate determination of CLO in blood is highly significant for treatment monitoring. This study describes the design and fabrication of a molecularly imprinted polymer (MIP)-based electrochemical sensor for CLO determination. This is the first MIP-based electrochemical application in the literature for CLO determination. Employing the thermal polymerization approach, the MIP was formed on the glassy carbon electrode (GCE) using CLO as the template, trans-3-(3-Pyridyl)acrylic acid (3,3-TA) as the functional monomer, and the support of zinc oxide nanoparticles (ZnO NPs). Elaborate characterizations in terms of surface morphology and electrochemistry were performed via scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) methods. An indirect approach was employed to determine CLO in standard solution, real human biological samples, and tablet formulation, using 5 × 10-3 M [Fe(CN)6]3-/4- solution as the redox probe. The limit of detection (LOD) values for the standard solution and serum sample were calculated as 2.9 × 10-11 M and 6.01 × 10-12 M, respectively. These values and recovery studies confirmed the sensor's sensitivity and feasibility. The measurements in the presence of similarly structured compounds (olanzapine and quetiapine fumarate) verified the sensor's superior selectivity. Moreover, the developed sensor's performance was compared and verified using an LC-MS/MS method using the student's t-test and F-test.

Current Analytical Methods for the Sensitive Assay of New-Generation Ovarian Cancer Drugs in Pharmaceutical and Biological Samples.

Ovarian cancer, which affects the female reproductive organs, is one of the most common types of cancer. Since this type of cancer has a high mortality rate from gynaecological cancers, the scientific community shows great interest in studies on its treatment. Chemotherapy, radiotherapy, and surgical treatment methods are used in its treatment. In the absence of targeted treatments in these treatment methods, side effects occur in patients, and patients show resistance to the drug. In addition, the underlying causes of ovarian cancer are still not fully known. The scientific world thinks that genetic factors, environmental conditions, and consumed foods may cause this cancer. The most important factor in the treatment of ovarian cancer is early diagnosis. Therefore, the drugs used in the treatment of ovarian cancer are platinum-based anticancer drugs. In addition to these drugs, the most preferred treatment method recently is targeted treatment approaches using poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors. In this review, studies on the sensitive analysis of the treatment methods of these new-generation drugs used in the treatment of ovarian cancer have been comprehensively examined. In addition, the basic features, structural aspects, and biological data of analytical methods used in treatments with new-generation drugs are explained. Analytical studies carried out in the literature in recent years aim to show future developments in how these new-generation drugs are used today and to guide future studies by comprehensively examining and explaining the structure-activity relationship, mechanism of action, toxicity, and pharmacokinetic studies. Finally, in this study, the methods used in the analysis of drugs used in the treatment of ovarian cancer and the studies conducted between 2015 and 2023 were discussed in detail.

Highly selective and sensitive molecularly imprinted sensors for the electrochemical assay of quercetin in methanol extracts of Rubus sanctus and Fragaria vesca.

Quercetin (QUE) is a powerful antioxidant and one of the common phenolic compounds found in plants, vegetables, and fruits, which has shown many pharmacological activities. The complex nature of the matrix in which QUE is found and its importance and potential uses in diverse applications force the researchers to develop selective and sensitive sensors. In the present work, a novel molecularly imprinted polymer (MIP)-based electrochemical sensor was fabricated for the selective and sensitive determination of the QUE in plant extracts and food supplements. Tryptophan methacrylate (TrpMA) was chosen as the functional monomer, whereas the photopolymerization (PP) method was applied using a glassy carbon electrode (GCE). Electrochemical and morphological characterizations of the developed sensor (TrpMA@QUE/MIP-GCE) were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The linear range of the developed sensor was determined to be in the range of 1.0-25 pM, while the limit of detection (LOD) was calculated to be 0.235 pM. In conclusion, The TrpMA@QUE/MIP-GCE sensor might be classified as a promising platform for selective and sensitive determination of QUE not only in plant extracts but also in commercial food supplements because of its reliability, reproducibility, repeatability, stability, and fast response time.

[Investigation of the Antibacterial Effect of Taraxacum officinale Extracts Extracted in Different Solvents on Bacteroides fragilis ATCC 25285 Standard Strain by Broth Microdilution Method]. / Farkli Çözücülerde Ekstrakte Edilen Taraxacum officinale Ekstraktlarinin Bacteroides fragilis ATCC 25285 Standart Susu Üzerindeki Antibakteriyel Etkisinin Sivi Mikrodilüsyon Yöntemiyle Arastirilmasi.

Bacteria causing hospital-associated infections continue to become resistant due to antibiotic resistance, which has become a global problem worldwide and accordingly, the antibiotic options used in the treatment of infectious diseases caused by these bacteria are limited. In the light of the data obtained from experimental studies on plants, it is thought that plant extracts may be a promising option in the treatment of infectious diseases. In this study, it was aimed to determine the antibacterial activity of Taraxacum officinale extracts on Bacteroides fragilis ATCC 25285 standard strain by broth microdilution method and to pioneer different studies that will investigate the antibacterial effects of plant extracts on resistant B.fragilis strains that cause hospital-acquired opportunistic infections after invasive interventions and trauma. In this study, the T.officinale plant collected as a result of field work was divided into root, leaf and flower parts and dried at 70 °C for 24 hours and then turned into powder. Dried plant samples were extracted in ethanol and methanol for 24 hours. The obtained extracts were stored at -80 °C to be used in the broth microdilution method. B.fragilis ATCC 25285 standard strain was used as the bacterial strain. As a result of the experiments performed with broth microdilution method, the MIC (minimum inhibitory concentration) value of root, leaf and flower extracts with ethanol was determined as 200 µg/ mL, the methanolic root extract as 100 µg/mL and the methanolic leaf and flower extracts as 200 µg/mL. As a result, ethanol and methanol plant extracts were found to be effective on B.fragilis strain.

Development of highly selective and sensitive molecularly imprinted polymer-based electrochemical sensors for tolvaptan assay in tablets and serum.

In this research, two different molecularly imprinted polymer (MIP)-based electrochemical sensors were proposed for the determination of tolvaptan (TOL). Photopolymerization (PP) and thermal polymerization (TP) techniques were developed for the determination of TOL. The advantages of MIP were used to design an electrochemical sensor for selective and sensitive determination of TOL. TOL was determined on a glassy carbon electrode (GCE) using differential pulse voltammetry (DPV) for both techniques. Some important parameters affecting the sensor efficiency, such as template/monomer ratio, PP and TP time, drop volume, removal solutions, removal and rebinding time, etc., were optimized. The surface characterization of the proposed MIP-based electrochemical sensors was carried out with electrochemical characterization by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) methods. It was extended with the scanning electron microscopy (SEM) technique. Under optimal conditions, the developed sensors showed good linearity between 1.0 × 10-11 M and 1.0 × 10-10 M, and 2.5 × 10-11 M and 2.5 × 10-10 M for PP and TP, respectively. Low detection limits (2.89 × 10-12 M (PP) and 1.88 × 10-13 M (TP)) were also obtained for TOL determination. The applicability of the proposed sensor was evaluated using tablet and commercial human serum samples. Interference and imprinting factor studies verified the selectivity and specificity of the proposed sensors, and the efficiency of the sensors was verified using an unprinted polymer for comparison at each step.

A molecularly imprinted polymer-based electrochemical sensor for the determination of tofacitinib.

Tofacitinib citrate (TOF) is a Janus kinase-3 inhibitor used for rheumatoid arthritis treatment. In this study, a molecularly imprinted polymer (MIP)-based sensor was produced using acrylamide as the functional monomer via photopolymerization technique for the electrochemical determination of TOF. This study is the first one to explain the electrochemical determination of TOF with a highly selective MIP-based sensor. The surface characterization of the MIP-based sensor was performed with scanning electron microscopy and energy-dispersive X-ray spectroscopy methods, and it was expanded with electrochemical characterization by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) methods. TOF determination was performed using differential pulse voltammetry (DPV) and EIS methods in standard solution and spiked serum sample in the linear range between 1×10-11 M and 1×10-10 M. Very low limit of detection and limit of quantification values were found, confirming the sensitivity of the sensor. Recovery analysis with spiked serum and tablet samples verified the sensor's accuracy and applicability using DPV and EIS methods. The selectivity of the sensor was confirmed with imprinting factor and interference studies, and the sensor performance was controlled using non-imprinted polymer for comparison at every step.

Carbon Nanomaterials-Based Novel Hybrid Platforms for Electrochemical Sensor Applications in Drug Analysis.

Nowadays, the rapid improvements in the medical and pharmaceutical fields increase the diversity and use of drugs. However, problems such as the use of multiple or combined drugs in the treatment of diseases and insensible use of over-the-counter drugs have caused concerns about the side-effect profiles and therapeutic ranges of drugs and environmental contamination and pollution problems due to pharmaceuticals waste. Therefore, the analysis of drugs in various media such as biological, pharmaceutical, and environmental samples is an important topic of discussion. Electrochemical methods are advantageous for sensor applications due to their easy application, low cost, versatility, high sensitivity, and environmentally-friendliness. Carbon nanomaterials such as diamond-like carbon thin films, carbon nanotubes, carbon nanofibers, graphene oxide, and nanodiamonds are used to enhance the performance of the electrochemical sensors with catalytic effects. To further improve this effect, it is aimed to create hybrid platforms by using different carbon nanomaterials together or with materials such as conductive polymers and ionic liquids. In this review, the most used carbon nanoforms will be evaluated in terms of electrochemical characterizations and physicochemical properties. Furthermore, the effect of hybrid platforms developed in the most recent studies on electrochemical sensors will be examined and evaluated in terms of drug analysis studies in the last five years.

In vitro antifungal activity of heterocyclic organoboron compounds against Trichophyton mentagrophytes and Microsporum canis obtained from clinical isolates.

The aim of this study was to investigate the in vitro activity of thirty-eight heterocyclic organoboron compounds (1a-o, 2a-j, 3a-m) against clinically isolated dermatophytes Trichophyton mentagrophytes and Microsporum canis. Minimum inhibitory concentrations (MICs) of compounds (1a-o, 2a-j, 3a-m) were determined according to published protocol Clinical and Laboratory Standards Institute (CLSI) M38-A2 broth microdilution method. The minimum fungicidal concentrations (MFCs) for both T. mentagrophytes and M. canis were found by subculturing each fungal suspension on potato dextrose agar. According to the results, heterocyclic organoboron compounds (1a-o, 2a-j, 3a-m) were found to be more effective against dermatophyte M. canis (MIC = 3.12-25 µg/ml) than T. mentagrophytes (MIC = 12.5-100 µg/ml). Our findings showed that 7-membered heterocyclic organoboron compounds (3a-m) (MIC = 12.5-50 µg/ml) have stronger in vitro antifungal activity against T. mentagrophytes than 5-membered heterocyclic organoboron compounds (1a-o, 2a-j) (MIC = 25-100 µg/ml). The MFC values for all compounds ranged from 6.25 to 200 µg/ml. The limited number of systemic antifungal agents used in the treatment of dermatophyte infections and the presence of side effects have led to the search for new treatment resources in recent years. Therefore, investigation of the effect of heterocyclic organoboron compounds against dermatophytes will be promising for the discovery of new antifungal compounds that have gained great importance today.

The investigation of serum levels of ADAMTS 5 and 8 (the A disintegrin and metalloproteinase with thrombospondin motifs) in the etiology of endometrial cancer.

The aim of this study was to investigate the serum levels of the A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5 and 8 in patients diagnosed with endometrial cancer. Our study included 41 patients diagnosed with endometrial cancer. The control group consisted of 41 patients diagnosed with benign endometrial pathology. The serum samples were centrifuged and stored at -80 °C. The serum levels of ADAMTS were significantly higher (p<.001), whereas the levels of ADAMTS 8 were significantly lower in patients diagnosed with cancer (p<.001). In addition to the presence of known factors in the aetiology of endometrial cancer, the effect of inflammatory factors and some new proteins has centred on the causes of tumourigenesis in recent years. In this sense, these proteins, called the ADAMTS, are the source of new studies.Impact StatementWhat is already known on this subject? When the recent studies about endometrial cancer are evaluated, it is seen that the effects of chronic inflammation and cytokines have gained importance in its aetiology. The A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) gene family consist of 19 proteases that play essential role in the formation of the extracellular matrix (ECM) and interact with inflammatory cytokines. These proteases and their substrates provide a wide range of functions in different tissues, including ECM remodelling, angiogenesis, fibrosis and coagulation.What the results of this study add? ADAMTS 5, which causes the degradation of the ECM with Aggrecanase activity, was found to be significantly higher in patients diagnosed with cancer and ADAMTS 8 with anti-angiogenesis activity was significantly lower in patients diagnosed with endometrial cancer.What the implications are of these findings for clinical practice and/or further research? In this study, it is understood that the effect of inflammatory mediators is remarkably important in the aetiology of endometrial cancer, as in many types of organ specific cancer.

Evaluation of Gonadotropin Responses and Response Times According to Two Different Cut-Off Values in Luteinizing Hormone Releasing Hormone Stimulation Test in Girls.

BACKGROUND: In this study, we aimed to evaluate FSH, LH responses obtained during LHRH-ST according to two different cut-off values, to determine the diagnostic response times, and to find the optimal blood collection times that could reduce the economic and time burden of LHRH-ST. MATERIALS AND METHODS: Patients who underwent LHRH-ST in our clinic with the preliminary diagnosis of precocious puberty (PP) between 01/08/2016 and 31/12/2017 were retrospectively enrolled to the study. In this study 207 girls with PP were included and some of them (102 according to C1 and 139 according to C2) had central PP (CPP). Test response and response times were evaluated according to both cut-off values of stimulated peak LH pubertal responses as 5 mIU/ml (the 1st cut-off = C1) and 3.3 mIU/ml (the 2nd cut-off = C2). RESULTS: Totally, 207 girls with a mean age of 7.5 ± 1.22 (3.4-9.5) years were included in the study. With LHRH-ST; 49.2% (n = 102), 67% (n = 139) of the cases were in pubertal period according to C1, C2, respectively. According to C1; pubertal LH was present in 94.1% (n = 96) of 102 patients who reached pubertal LH value in 45th minutes. The highest pubertal response was obtained in the 45th minute. According to C2, of 139 patients who reached pubertal LH; pubertal LH was determined in 98.5% (n = 137) in the 45th minute. Pubertal LH levels were determined according to both cut-off values in all 27 patients with baseline LH ≥0.31 mIU/ml. CONCLUSION: It was determined that measuring LH at 45th minutes during LHRH-ST was sufficient in 94.1% of the cases according to C1 and 97.1% of the cases according to C2. It was concluded that the 30th, 45th, and 60th minute samples were enough to assess pubertal LH response in 100%of the cases. If the basal LH is found to be ≥0.31 mIU/ml in girls with puberty findings, we recommend that the diagnosis of precocious puberty would be made without performing LHRH-ST.

Detection of resistivity for antibiotics by probabilistic neural networks.

This paper presents the use of probabilistic neural networks (PNNs) for detection of resistivity for antibiotics (resistant and sensitive). The PNN is trained on the resistivity or sensitivity to the antibiotics of each record in the Salmonella database. Estimation of the whole parameter space for the PNN was performed by the maximum-likelihood (ML) estimation method. The expectation-maximization (EM) approach can help to achieve the ML estimation via iterative computation. Resistivity and sensitivity of the three antibiotics (ampicillin, chloramphenicol disks and trimethoprim-sulfamethoxazole) were classified with high accuracies by the PNN. The obtained results demonstrated the success of the PNN to help in detection of resistivity for antibiotics.

Characterization of ESBL (SHV-12) producing clinical isolate of Enterobacter aerogenes from a tertiary care hospital in Nigeria.

BACKGROUND: We studied the beta-lactamases of an E. aerogenes isolate recovered from the blood of a two-year-old patient. The isolate demonstrated a disk-diffusion phenotype typical for an AmpC-ESBL co-producer. METHODS: Microbiology studies were performed according to standard protocols. The resistance gene was identified by transconjugation and cloning experiments. RESULTS: By transconjugation only a narrow spectrum beta-lactamase (TEM-1) encoded on a small plasmid was transmitted. The ESBL was cloned and expressed in an E. coli host. Sequence analysis of the recombinant plasmid revealed blaSHV-12 associated to the insertion sequence, IS26. CONCLUSION: This is the first study demonstrated the occurrence of SHV-12 in Nigeria.

Characterization of extended-spectrum beta-lactamase-producing Salmonella isolates in a children's hospital in Ankara--first report of SHV-2a and SHV-9 in Salmonella spp. from Turkey.

The rate of in vitro resistance to various antimicrobials in 179 consecutive isolates of Salmonella spp., which included serogroups D (109), B (52), C1 (10) and C2 (8) isolated from children, was investigated. Production of extended-spectrum beta-lactamase (ESBL) was studied in ampicillin-resistant isolates. Antimicrobial susceptibilities were determined by disk diffusion tests and by BIOMIC video reader system. Overall resistance rates to ampicillin and amoxicillin/clavulanate were 26.3% and 10.6%, respectively. Resistance to ceftriaxone and ceftazidime was 3.3%. Resistance rates for chloramphenicol, trimethoprim-sulfamethoxazole, ciprofloxacin, amikacin and gentamicin were 40.7%, 31.3%, 2.2%, 2.2% and 6.1%, respectively. beta-lactamase production was detected in 42 isolates. Mating out experiments, isoelectric focusing, dot blot hybridization, polymerase chain reaction (PCR) and sequencing were performed on two S. paratyphi B isolates that produced ESBLs. One isolate produced SHV-2 and TEM-1 and the other produced SHV-2a, SHV-5a (SHV-9) and TEM-1. This is the first report of SHV-2a and SHV-5a (SHV-9) in S. paratyphi B in Turkey.

Emergence and spread of carbapenem-resistant Acinetobacter baumannii in a tertiary care hospital in Turkey.

An intensive care unit (ICU)-based OXA-23-producing multiple-drug resistant Acinetobacter baumannii (MDRAB) outbreak was detected between October 2005 and October 2006. A total of 47 patients were infected/colonized with the outbreak strain. Clinical data were available from 37 patients. The all-cause mortality rate among the patients exposed to the epidemic strain was 35% (13/37). The outbreak strain and the resistance determinants were characterized both by microbiological methods and by molecular techniques. Cloning and sequencing experiments identified ISAbaI-associated bla(oxa-23) on the chromosome. Screening of imipenem-resistant Acinetobacter isolated from the ICU during the outbreak period with PCR identified 97 isolates as positive for the ISAbaI-bla(oxa-23) structure. Pulsed-field gel electrophoresis and plasmid analyses with selected nonrepetitive isolates revealed the clonality. Disk diffusion on cloxacillin-supplemented agar media and the real-time PCR experiments showed that outbreak isolates are overexpressing the ampC enzyme. This study highlights the occurrence of OXA-23-producing and ampC-overexpressing MDRAB in ICUs.

Evaluation of disseminated candidiasis on an experimental animal model: a fourier transform infrared study.

Invasive candidiasis, defined as candidemia and disseminated candidiasis, is the most common fungal infection in hospitalized patients. In the current study, we used Fourier transform infrared (FT-IR) spectroscopy as a rapid, non-perturbing technique to investigate the effects of disseminated candidiasis on mouse liver tissues at the molecular level. The results revealed that the infection caused compositional changes in the tissues by decreasing the lipid content and the ratio of the saturated lipids to unsaturated lipids. An increase in the lipid/protein ratio was also observed. In addition, investigation of the olefinic band at 3014 cm(-1) showed that lipid peroxidation took place in the infected samples. These results indicate that FT-IR spectroscopy is a promising technique for the evaluation and diagnosis of disseminated candidiasis.

The investigation of Chlamydophila pneumoniae in patients with multiple sclerosis.

Totally 32 cerebrospinal fluid samples from Multiple sclerosis (MS) patients were collected. DNA was extracted by High Pure PCR Template Preparation Kit. Two genomic segments, outer membrane protein genes ompA and omp9, were targeted for the detection of C. pneumoniae DNA in the samples by PCR tests. To detect ompA, a nested-PCR assay was designed, whereas for omp9, a PCR-Enyzme immunoassay (PCR-EIA) depending on streptavidin-biotin capture and dig detection of the PCR products was performed. C. pneumoniae DNA was not detected by each assays in patient samples.

Synthesis and structure-antibacterial activity relationship investigation of isomeric 2,3,5-substituted perhydropyrrolo[3,4-d]isoxazole-4,6-diones.

The synthesis of 2,3,5-substituted perhydropyrrolo[3,4-d]isoxazole-4,6-diones (44 compounds) has been accomplished by the cycloaddition reaction of N-methyl-C-arylnitrones with N-substituted maleimides. The compounds were screened for their antibacterial activities and most of them exhibited activity against Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 25923). cis-3a and cis-3d were found fairly effective against E. faecalis (ATCC 29212) and S. aureus (ATCC 25923) with MIC values of 25 and 50microg/ml. With the changes of cis isomers of the compounds to trans, their antibacterial activities also changed against the bacteria studied. First, pharmacophoric fragments had been calculated in accordance with the rules of the electronic-topological method (ETM). Next, both active compounds and pharmacophores had been projected to the nodes of Kohonen's self-organizing maps (SOM) to obtain the weights of pharmacophore fragments as numerical descriptors, that were used after this for the associative neural networks (ASNN) training. A model for the activity prediction was developed as the result of training the ASNNs.

Evaluation of a chromogenic medium for rapid detection of extended spectrum beta-lactamase producing Salmonella spp.

BACKGROUND & OBJECTIVES: Salmonella spp. resistant to second- and third-generation cephalosporins and related antibiotics by production of various extended-spectrum beta-lactamases (ESBLs) are on the rise in Turkey. Early detection of ESBL producing Salmonella is important to institute appropriate treatment in time. In this study rapid detection of ESBL production among clinical isolates of Salmonella was evaluated using double-disk synergy test in a new chromogenic medium. The colour of the medium changes from red to yellow with bacterial growth and red circular inhibition zones are produced around disks containing antibacterials. METHODS: A total of 182 clinical isolates of Salmonella were evaluated in this study. The presence of ESBLs in clinical isolates was determined by double-disk synergy test using Mueller-Hinton (MH) agar and Quicolor E&S agar plates. RESULTS: Six isolates were shown to harbour ESBL enzymes with double disk synergy test by Mueller Hinton agar. The same results were obtained using Quicolor E&S agar after 4-6 h by changing its colour in response to the metabolic activity of growing bacteria. INTERPRETATION & CONCLUSION: Our findings showed that with this new medium, the results can be evaluated rapidly within 4-6 h and the enhancement of inhibition zones can be easily detected with the colour changes thus enabling the treating physician to institute the right treatment regimen immediately.

High prevalence of OXA-51-type class D beta-lactamases among ceftazidime-resistant clinical isolates of Acinetobacter spp.: co-existence with OXA-58 in multiple centres.

OBJECTIVES: This study was designed to demonstrate the prevalence of the newly discovered carbapenem-hydrolysing class D enzymes, OXA-51-type and OXA-58, among clinical isolates of Acinetobacter spp. METHODS: A total of 72 isolates from six centres were studied. Isolates were screened by PCR with specific primers for bla(OXA-51-type) and bla(OXA-58). PCR products were sequence-analysed. Plasmids were digested with EcoRV and genomic DNAs were digested with PvuII. Hybridization experiments were done with digoxigenin-labelled specific probes. Macro-restriction analysis was done on SmaI-digested genomic DNAs. RESULTS: A total of 56 (77.8%) isolates were positive for bla(OXA-51-type) genes. Sequence analysis of the products from 23 selected isolates revealed the occurrence of multiple alleles in all contributing centres. The bla(OXA-58) gene was detected among 10 isolates from five centres. All were also positive for bla(OXA-51-type) genes. Among the bla(OXA-58)-positive isolates, two from the same centre were positive for a novel OXA-51 allele (OXA-86). Southern hybridization of plasmids and of genomic DNAs suggested that bla(OXA-51-type) genes are located on chromosomes whereas bla(OXA-58) genes are plasmid borne in these 10 isolates. Plasmid profiles and pulsed-field gel electrophoresis patterns indicated the spread of the bla(OXA-58) gene among multiple clones. The bla(OXA-51-type) and bla(OXA-58) co-carrier strains were mostly associated with a pandrug-resistant phenotype. CONCLUSIONS: This study indicated that bla(OXA-58)-bearing plasmids are readily spreading among multiple clones of the bla(OXA-51-type)-bearing clinical isolates of Acinetobacter spp. Since these isolates are highly resistant to antibiotics this finding indicates the existence of a significant problem in Turkish hospitals.