Is It Possible to Restrain OER on Simple Carbon Electrodes to Efficiently Electrooxidize Organic Pollutants?

This paper presents a comparative analysis of three carbon-based electrodes: bare multiwalled carbon nanotubes (MWCNT), SnO2/MWCNT, and PbO2/graphene-nanoribbons (PbO2/GNR) composites, as anodes for the electrooxidative degradation of Rhodamine B as a model organic pollutant. Anodic electrooxidation of Rhodamine B was performed on all three electrodes, and the decolorization efficiency was found to increase in the order MWCNT < PbO2/GNR < SnO2/MWCNT. The electrodes were characterized by X-ray photoelectron spectroscopy (XPS) and linear sweep voltammetry (LSV). It was proposed that, in the 0.1 M Na2SO4 applied as electrolyte, observed decolorization mainly occurs in the interaction of Rhodamine B with OH radical adsorbed on the anode. Finally, the obtained results were complemented with Density Functional Theory (DFT) calculations of OH-radical interaction with appropriate model surfaces: graphene(0001), SnO2(001), and PbO2(001). It was found that the stabilization of adsorbed OH-radical on metal oxide spots (SnO2 or PbO2) compared to carbon is responsible for the improved efficiency of composites in the degradation of Rhodamine B. The observed ability of metal oxides to improve the electrooxidative potential of carbon towards organic compounds can be useful in the future design of appropriate anodes.

The diagnostic utility of the "Thwaites' system" and "lancet consensus scoring system" in tuberculous vs. non-tuberculous subacute and chronic meningitis: multicenter analysis of 395 adult patients.

BACKGROUND: Tuberculous meningitis (TBM) represents a diagnostic and management challenge to clinicians. The "Thwaites' system" and "Lancet consensus scoring system" are utilized to differentiate TBM from bacterial meningitis but their utility in subacute and chronic meningitis where TBM is an important consideration is unknown. METHODS: A multicenter retrospective study of adults with subacute and chronic meningitis, defined by symptoms greater than 5 days and less than 30 days for subacute meningitis (SAM) and greater than 30 days for chronic meningitis (CM). The "Thwaites' system" and "Lancet consensus scoring system" scores and the diagnostic accuracy by sensitivity, specificity, and area under the curve of receiver operating curve (AUC-ROC) were calculated. The "Thwaites' system" and "Lancet consensus scoring system" suggest a high probability of TBM with scores ≤4, and with scores of ≥12, respectively. RESULTS: A total of 395 patients were identified; 313 (79.2%) had subacute and 82 (20.8%) with chronic meningitis. Patients with chronic meningitis were more likely caused by tuberculosis and had higher rates of HIV infection (P < 0.001). A total of 162 patients with TBM and 233 patients with non-TBM had unknown (140, 60.1%), fungal (41, 17.6%), viral (29, 12.4%), miscellaneous (16, 6.7%), and bacterial (7, 3.0%) etiologies. TMB patients were older and presented with lower Glasgow coma scores, lower CSF glucose and higher CSF protein (P < 0.001). Both criteria were able to distinguish TBM from bacterial meningitis; only the Lancet score was able to differentiate TBM from fungal, viral, and unknown etiologies even though significant overlap occurred between the etiologies (P < .001). Both criteria showed poor diagnostic accuracy to distinguish TBM from non-TBM etiologies (AUC-ROC was <. 5), but Lancet consensus scoring system was fair in diagnosing TBM (AUC-ROC was .738), sensitivity of 50%, and specificity of 89.3%. CONCLUSION: Both criteria can be helpful in distinguishing TBM from bacterial meningitis, but only the Lancet consensus scoring system can help differentiate TBM from meningitis caused by fungal, viral and unknown etiologies even though significant overlap occurs and the overall diagnostic accuracy of both criteria were either poor or fair.

Longitudinal Outbreak of Multidrug-Resistant Tuberculosis in a Hospital Setting, Serbia.

A retrospective population-based molecular epidemiologic study of multidrug-resistant Mycobacterium tuberculosis complex strains in Serbia (2008-2014) revealed an outbreak of TUR genotype strains in a psychiatric hospital starting around 1990. Drug unavailability, poor infection control, and schizophrenia likely fueled acquisition of additional resistance and bacterial fitness-related mutations over 2 decades.

Hydrocephalus and vasculitis delay therapeutic responses in tuberculous meninigitis: Results of Haydarpasa-III study.

AIMS: There is no report on the factors affecting the resolution of symptoms related to meningitis during treatment of tuberculous meningitis (TBM). Thus, we examined the factors associated with early therapeutic responses. MATERIALS AND METHODS: This multicenter study included 507 patients with microbiologically confirmed TBM. However, 94 patients eligible for the analysis were included in this study from 24 centers. Six out of 94 patients died and the statistical analysis was performed with 88 survivors. Early and late responder groups were compared in the statistical analysis. P < 0.05 were considered to show a significant difference. RESULTS: In the multivariate analysis, the presence of vasculitis (P = 0.029, OR = 10.491 [95% CI, 1.27-86.83]) was found to be significantly associated with a delayed fever response whereas hydrocephalus was associated with altered mental status for >9 days duration (P = 0.005, OR = 5.740 [95% CI, 1.68-19.57]). According to linear regression analysis, fever was significantly persisting (>7 days) in the presence of vasculitis (17.5 vs. 7, P< 0.001) and hydrocephalus (11 vs. 7, P = 0.029). Hydrocephalus was significantly associated with persisting headache (21 vs. 12, P = 0.025), delayed recovery of consciousness (19.5 vs. 7, P = 0.001), and a delay in complete recovery (21 vs. 14, P = 0.007) in the linear regression analysis. Following institution of treatment, the complaints seemed to disappear in up to 2 weeks among TBM survivors. CONCLUSIONS: In the absence of hydrocephalus or vasculitis, one week of anti-tuberculosis treatment seems to be adequate for the resolution of TBM symptoms. Hydrocephalus and vasculitis delay the resolution of TBM symptoms in response to antimycobacterial treatment.

Antituberculosis drug resistance patterns in adults with tuberculous meningitis: results of haydarpasa-iv study.

BACKGROUND: Tuberculous meningitis (TBM) caused by Mycobacterium tuberculosis resistant to antituberculosis drugs is an increasingly common clinical problem. This study aimed to evaluate drug resistance profiles of TBM isolates in adult patients in nine European countries involving 32 centers to provide insight into the empiric treatment of TBM. METHODS: Mycobacterium tuberculosis was cultured from the cerebrospinal fluid (CSF) of 142 patients and was tested for susceptibility to first-line antituberculosis drugs, streptomycin (SM), isoniazid (INH), rifampicin (RIF) and ethambutol (EMB). RESULTS: Twenty of 142 isolates (14.1 %) were resistant to at least one antituberculosis drug, and five (3.5 %) were resistant to at least INH and RIF, [multidrug resistant (MDR)]. The resistance rate was 12, 4.9, 4.2 and 3.5 % for INH, SM, EMB and RIF, respectively. The monoresistance rate was 6.3, 1.4 and 0.7 % for INH, SM and EMB respectively. There was no monoresistance to RIF. The mortality rate was 23.8 % in fully susceptible cases while it was 33.3 % for those exhibiting monoresistance to INH, and 40 % in cases with MDR-TBM. In compared to patients without resistance to any first-line drug, the relative risk of death for INH-monoresistance and MDR-TBM was 1.60 (95 % CI, 0.38-6.82) and 2.14 (95 % CI, 0:34-13:42), respectively. CONCLUSION: INH-resistance and MDR rates seemed not to be worrisome in our study. However, considering their adverse effects on treatment, rapid detection of resistance to at least INH and RIF would be most beneficial for designing anti-TB therapy. Still, empiric TBM treatment should be started immediately without waiting the drug susceptibility testing.

Biofilm Formation among Stenotrophomonas maltophilia Isolates Has Clinical Relevance: The ANSELM Prospective Multicenter Study.

The ability to form biofilms is a recognized trait of Stenotrophomonas maltophilia, but the extent of its clinical relevance is still unclear. The present multicenter prospective study (ANSELM) aims at investigating the association between biofilm formation and clinical outcomes of S. maltophilia infections. One hundred and nine isolates were collected from various geographical origins and stratified according to their clinical relevance. Biofilm formation was evaluated by the microtiter plate assay and correlated with microbiological and clinical data from the associated strains. Antibiotic susceptibility of the planktonic cells was tested by the disk diffusion technique, while antibiotic activity against mature biofilms was spectrophotometrically assessed. Most strains (91.7%) were able to form biofilm, although bloodborne strains produced biofilm amounts significantly higher than strains causing hospital- rather than community-acquired infections, and those recognized as "definite" pathogens. Biofilm formation efficiency was positively correlated with mechanical ventilation (p = 0.032), whereas a negative relationship was found with antibiotic resistance (r2 = 0.107; p < 0.001), specifically in the case of the pathogenic strains. Mature S. maltophilia biofilms were markedly more resistant (up to 128 times) to cotrimoxazole and levofloxacin compared with their planktonic counterparts, especially in the case of bloodborne strains. Our findings indicate that biofilm formation by S. maltophilia is obviously a contributing factor in the pathogenesis of infections, especially in deep ones, thus warranting additional studies with larger cohort of patients and isolates.

Pulmonary isolation and clinical relevance of nontuberculous mycobacteria during nationwide survey in Serbia, 2010-2015.

The rates of pulmonary colonization and disease due to nontuberculous mycobacteria (NTM) appear to be increasing globally, but diversity of species recovered as well as clinical relevance of NTM isolates differ considerably by geographic region. The first nationwide study of isolation frequency and clinical significance of NTM in Serbia included all patients with respiratory specimens yielding a positive NTM culture over the six-year period, 2010-2015. We analyzed trends in annual NTM isolation and NTM pulmonary disease (PD) incidence rates, with NTM PD cases defined in accordance with microbiological criteria established by the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA). 777 pulmonary NTM isolates were collected from 565 patients, of whom 126 (22.3%) met the ATS/IDSA criteria. The annual NTM isolation and NTM PD incidence rates per 100,000 changed over 2010-2015 from 0.9 to 1.6 (p = 0.1746) and from 0.18 to 0.48 (p = f0.0040), respectively. Both isolation and disease rates increased considerably with age, while higher NTM PD rates were also associated with residence in urbanized areas. Diversity of NTM species isolated was shown to be region-specific, with M. xenopi as the most prevalent species (17.3%), and increasing isolation rates of rapid growing mycobacteria (RGM) (p = 0.0072). M. xenopi was also the most common cause of NTM PD (28.6%), followed by RGM (27.8%). With 73% clinically relevant isolates, M. abscessus was identified as the most clinically relevant NTM species. While NTM PD obviously remains a rare disease in Serbia, the overall results justify recognition of NTM as pathogens of rising importance, and require further characterization of their epidemiology in the country.

Brain abscess due to Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans, a constituent of the oral flora, is a rare cause of brain abscesses. We report the case of a 47-year-old male who presented with multiple brain abscesses due to this organism, presumably originating from his poor dentition. Problems met in isolating and identifying A. actinomycetemcomitans suggest that its true rate of isolation from non-oral samples may have been underestimated.

Hamsi scoring in the prediction of unfavorable outcomes from tuberculous meningitis: results of Haydarpasa-II study.

Predicting unfavorable outcome is of paramount importance in clinical decision making. Accordingly, we designed this multinational study, which provided the largest case series of tuberculous meningitis (TBM). 43 centers from 14 countries (Albania, Croatia, Denmark, Egypt, France, Hungary, Iraq, Italy, Macedonia, Romania, Serbia, Slovenia, Syria, Turkey) submitted data of microbiologically confirmed TBM patients hospitalized between 2000 and 2012. Unfavorable outcome was defined as survival with significant sequela or death. In developing our index, binary logistic regression models were constructed via 200 replicates of database by bootstrap resampling methodology. The final model was built according to the selection frequencies of variables. The severity scale included variables with arbitrary scores proportional to predictive powers of terms in the final model. The final model was internally validated by bootstrap resampling. A total of 507 patients' data were submitted among which 165 had unfavorable outcome. Eighty-six patients died while 119 had different neurological sequelae in 79 (16%) patients. The full model included 13 variables. Age, nausea, vomiting, altered consciousness, hydrocephalus, vasculitis, immunosuppression, diabetes mellitus and neurological deficit remained in the final model. Scores 1-3 were assigned to the variables in the severity scale, which included scores of 1-6. The distribution of mortality for the scores 1-6 was 3.4, 8.2, 20.6, 31, 30 and 40.1%, respectively. Altered consciousness, diabetes mellitus, immunosuppression, neurological deficits, hydrocephalus, and vasculitis predicted the unfavorable outcome in the scoring and the cumulative score provided a linear estimation of prognosis.

Evolutionary history and global spread of the Mycobacterium tuberculosis Beijing lineage.

Mycobacterium tuberculosis strains of the Beijing lineage are globally distributed and are associated with the massive spread of multidrug-resistant (MDR) tuberculosis in Eurasia. Here we reconstructed the biogeographical structure and evolutionary history of this lineage by genetic analysis of 4,987 isolates from 99 countries and whole-genome sequencing of 110 representative isolates. We show that this lineage initially originated in the Far East, from where it radiated worldwide in several waves. We detected successive increases in population size for this pathogen over the last 200 years, practically coinciding with the Industrial Revolution, the First World War and HIV epidemics. Two MDR clones of this lineage started to spread throughout central Asia and Russia concomitantly with the collapse of the public health system in the former Soviet Union. Mutations identified in genes putatively under positive selection and associated with virulence might have favored the expansion of the most successful branches of the lineage.

[Undiagnosed tuberculosis as clinical, epidemiological and medicolegal problem: report of two cases].

The authors present two cases of undiagnosed tuberculosis in order to point out clinical, epidemiological and medicolegal importance of such cases. The first patient was a 29-year-old woman, who died after 10-day hospital treatment, but true nature of her disease remained undiscovered. Due to her known marital problems, as well as numerous bruises developed as a consequence of hemorrhagic syndrome, violent death caused by injuries inflicted by her husband was suspected. Medicolegal autopsy and microscopic examination revealed fatal tuberculosis of the lungs, and small and large intestines. In another case, a 35-year-old male died suddenly and unexpectedly, being found dead in his flat where numerous blood traces were noticed during the scene investigation. Therefore, possible homicide was suspected. Medicolegal investigation proved pulmonary tuberculosis as a cause of natural death. Presented cases point out the fact that even nowadays both pulmonary and extrapulmonary tuberculosis may remain clinically undiscovered, even when this disease is a cause of death. Hence, physicians should always keep in mind possible tuberculosis, especially in patients with long-lasting typical symptoms and signs. In both reported cases, the individuals suffered from cavernous pulmonary tuberculosis being thus a permanent source of infection. From medicolegal point of view, described cases represent examples of so called suspicious natural death. On the other hand, the fact that fatal tuberculosis remained clinically undiagnosed may make physicians be accused of medical negligence and malpractice.

[Microbiological diagnosis of tuberculosis in Serbia in the period 2001-2003].

INTRODUCTION: The National tuberculosis Reference Laboratory (NTRL) and the National TB Laboratory Network in Serbia, provided data on drug susceptibility profiles of M. tuberculosis, incidence of TB among laboratory workers and on protective measures. MATERIAL AND METHODS: The TB laboratory network in Serbia comprises 46 laboratories. 11 laboratories perform acid fast microscopy only, 24 perform microscopic and culture examinations, and complete identification and drug susceptibility testing (DST) is performed in 11 laboratories. Protective measures for laboratory workers are mostly inadequate. Four cases of occupational TB were reported over the study period. RESULTS: DST was performed in 61.8% to 62.8% of bacteriologically proven TB cases. Isolates of M. tuberculosis strains showing drug-resistance ranged from 7.9% to 8.9%, while multidrug resistant (MDR) isolates varied from 2.2% to 2.5%. In order to determine the accuracy of DST in 6 local laboratories, NTRL carried out a quality assurance program for DST. Four laboratories reached 100% agreement with NTRL for rifampicin. At least 90% agreement with NTRL for isoniazid was achieved in three tested laboratories. CONCLUSION: A relatively low and stable rates of drug-resistant and MDR TB in our study indicate that the situation in Serbia is still satisfactory. However, a reliable surveillance of drug-resistant TB in the region requires routine DST of all patients with culture confirmed TB. This is one of the goals included in the new National TB Program. In summary, all laboratories in Serbia should be included in the quality assurance program and their number should be reduced in accordance with the annual number of analyses performed, geographical location and results of proficiency testing.

Isolation and molecular characterization of Staphylococcus sciuri in the hospital environment.

Staphylococcus sciuri is a principally animal-associated bacterial species, but its clinical relevance for humans is increasing. Our study aimed to provide the first insight into the prevalence of this bacterium in a hospital environment. A 3-month surveillance was conducted in a hospital located in Belgrade, Serbia, and 1,028 samples taken from hands of medical personnel, medical devices, and various hospital surfaces were screened for S. sciuri presence. In total, 108 isolates were obtained, which resulted in a relatively high rate of colonization (10.5%). These isolates, along with 7 S. sciuri strains previously isolated in the same hospital (n = 115), were phenotypically and genotypically characterized. Antimicrobial susceptibility testing revealed that 73% of the strains were resistant to one or more antibiotics, with 4.3% strains displaying multiresistance. Examination of 16S-23S ribosomal DNA intergenic spacer length polymorphism identified the strains at the subspecies level, and 74 (64.3%) strains of S. sciuri subsp. sciuri, 37 (32.2%) strains of S. sciuri subsp. rodentium, and 4 (3.5%) strains of S. sciuri subsp. carnaticus were established. Pulsed-field gel electrophoresis (PFGE) analysis showed 21 distinct pulsotypes, including 17 main types and 4 subtypes. One dominant cluster with 62 strains was found, while 19 (90.5%) of the PFGE types and subtypes identified had 5 or fewer strains. The predominance of small PFGE clusters suggests that the ubiquitous presence of S. sciuri in the outside environment presents the continuous source for colonization of the hospital environment. The presence of one dominant PFGE cluster of strains indicates that some S. sciuri strains may be capable for adaptation to hospital environment conditions and continuous existence in this environment.

[Rapid laboratory diagnosis of tuberculosis in clinical practice]. / Brza bakterioloska dijagnostika tuberkuloze u klinickoj praksi.

The laboratory diagnosis of tuberculosis relies on direct microscopy of smears for acid-fast bacilli and culturing. Microscopy is a rapid, but neither sensitive nor specific diagnostic method. Cultivation on solid media is a time-consuming procedure, and isolation and identification of Mycobacterium tuberculosis takes 3-8 weeks. Introduction of new selective liquid media with a sensitive growth-detection system, dramatically decreased time necessary for isolation and susceptibility testing, so that positive results can be obtained in two weeks. However, wide use of these systems is limited by high cost of instruments and media. Nucleic acid amplification techniques have in recent years been introduced in clinical laboratories for diagnosis of tuberculosis. Amplification techniques are highly sensitive and specific, and positive results are available in a few hours. Nevertheless, molecular methods cannot replace culturing, when drug susceptibility testing is required.

[Use of IS6110 polymorphism analysis in molecular epidemiological studies of tuberculosis (Belgrade study results)]. / Polimorfizam IS6110 u genomu Mycobacterium tuberculosis kao osnov molekularnih epidemioloskih studija tuberkuloze na primeru rezultata beogradske studije.

Tuberculosis (TB) remains a major health problem worldwide. One of the main approaches to tackling TB today is the control of transmission of the disease through monitoring the transmission of specific strains of Mycobacterium tuberculosis. In the past, efforts to type strains of M. tuberculosis were hampered by the lack of strain-specific phenotypic markers. In recent years, novel approaches to studying the epidemiology of TB have been provided by molecular biological techniques based on DNA fingerprinting. The most widely used polymorphic marker is the transposable element IS6110, which is an insertion sequence found throughout M. tuberculosis complex. It is a highly polymorphic marker which varies in both copy number and location in the M. tuberculosis genome. A standardized methodology for IS6110 DNA fingerpriniting of M. tuberculosis exploits restriction fragment length polymorphism analysis. To date, IS6110 fingerprinting has been successfully used to trace the TB transmission in different regions and populations, to quantify the relative contribution of recent infection to the TB population burden, to answer the question of endogenous reactivation versus exogenous reinfection, to trace small-scale outbreaks of TB, to analyze spread of drug-resistant and multidrug resistant strains, to confirm laboratory cross-contaminations, etc. The objective of this study was to illustrate the basic principles of molecular epidemilological studies of TB. Results of the study, which provided the first insight into the status of TB in Belgrade based on implementation of molecular methods, were used as an example.

Molecular epidemiology of pulmonary tuberculosis in belgrade, central serbia.

In order to gain precise data on the actual epidemiology of tuberculosis (TB) in Belgrade, central Serbia, we conducted the molecular epidemiological investigation described herein. IS6110 restriction fragment length polymorphism (RFLP) typing of 176 Mycobacterium tuberculosis isolates was performed. These strains were obtained from 48.4% of all patients diagnosed with culture-proven pulmonary TB from April through September 1998 and from May through October 1999. Clusters containing strains with identical RFLP IS6110 patterns were assumed to have arisen from recent transmission. Of the 176 cases, 55 (31.2%) were grouped into 23 clusters ranging in size from two to six patients. Nearly 80% of clustered patients were directly interviewed, and transmission between family-unrelated contacts was found to be predominant in the study population. Classical contact investigation identified only 2 (3.6%) of the 55 clustered patients. The clustering of TB patients was not associated with any demographic or clinical characteristic other than infection with multidrug-resistant (MDR) M. tuberculosis strains. Nearly 70% of MDR strains were clustered, which indicates active transmission of MDR TB in Belgrade. However, this was not observed by conventional epidemiologic surveillance. In conclusion, the first molecular epidemiologic analysis of TB in the region revealed frequent recent transmission of TB and pointed out significant shortcomings of the current concept for conventional contact tracing. The results presented also demonstrate that transmission of MDR TB in Belgrade is not optimally controlled, and they provide support for the development of improved control strategies, including application of molecular methods.

[Current diagnosis and treatment of the osteoarticular tuberculosis]. / Savremena dijagnostika i lecenje kostnosglobne tuberkuloze.

In 1993, tuberculosis was recognized as global medical problem by WHO. Recurring flare-up of this disease was triggered by difficult socioeconomic situation of the countries in transition, current development of immunocompromising diseases, and some other factors have contributed, too. The osteoarticular tuberculosis has been always postprimary and localized form of the disease, which, due to certain similarity to some other osteoarticular diseases, has been challenge for orthopaedic surgeons both from diagnostic and treatment aspects. Bacteriological diagnostics has had a limited value due to application of recommended tuberculostatic medication before obtaining specimens from bones or joints; and, on the other hand, rapid bacteriological methods, because of their expensive equipment, could be carried out in large mycobacteriology laboratories only. New visualizing methods, CT and MRI, have been particularly important for detection and monitoring of tuberculosis process in the spine during the early stage of the disease, what is impossible to achieve with native radiograms. Programmed administration of tuberculostatic drugs both in non-operative and surgical treatment has been proven necessary.