Isolation and phenotypic characterization of Gallibacterium anatis biovar haemolytica from a hen with hemorrhagic ooforitis

Objective: the isolation and phenotypically identification of a Gallibacterium anatis biovar haemolytica strain from a hen with hemorrhagic ooforitis; the antimicrobial susceptibility testing of this isolate. Methods and results: a strain of G. anatis biovar haemolytica, was isolated and phenotypic identified by morphological, cultural and biochemical characters examination, with API 20 E, API 20 NE, API STAPH, API ZYM tests and ABIS online software. The antimicrobial susceptibility of the isolate was performed using the standard disk diffusion method. Conclusions: a strain of G. anatis biovar haemolytica was isolated and phenotypically identified from a hen. From our knowledge, this is the first reporting in Romania of isolation and identification of G. anatis biovar haemolytica. The Gah IDSA 161 strain could be phenotypic identified only by ABIS on line software, Pasteurellaceae Database version, unifying the results of four API kits and other biochemical tests. The isolate showed a multi-drug resistant profile to tetracyclines (tetracycline, oxitetracycline, doxicyclin), floroquinolones (enrofloxacin, ciprofloxacin), ampicillin, trimethoprim, nalidixic acid, clindamycin, and it was susceptible to sulfonamide, sulfomethoxazole/trimethoprim, gentamicin, cephalothin, streptomycin, amoxicilin/clavulanic acid.

Evaluation of Identification and Susceptibility for Candida Spp. Isolated Directly from Positive Blood Culture Bottles

Determination of the susceptibility profile of isolates of Candida from blood culture bottles is extremely important for correctly guiding patient pharmacotherapy. The aim of this study was to compare the results of analysis of Candida isolated directly from blood culture bottles by the VITEK MS MALDI-TOF identification system and the fluconazole disk diffusion assay with those of standard identification methods. Testing directly from the bottle allowed results 24 to 48 hours quicker than the standard method. There was a categorical agreement of 51.64% (47 of 91 samples) between the results of analysis directly from the bottle and analysis by the standard method. Regarding species identification, there was 96.15% agreement for Candida parapsilosis (25 of 26 samples). Categorical agreement between the rapid and standard disk diffusion methods was 95%, and the agreement between the rapid disk diffusion method and the broth microdilution method was 97%. Only minor errors in the rapid method were observed: 3 (5%) in the standard disk diffusion method and 2 (3%) in the broth microdilution method. Our study concluded that the rapid disk diffusion method for fluconazole is a fast, easy, reproducible, and consistent method. Its timely implementation for testing antifungal agents in the clinical microbiology laboratory can help reduce profile release times, thus helping to determine the most appropriate antifungal treatment.

Rationale for the Combined Use of Biological Processes and AOPs in Wastewater Treatment Tasks

This paper aims to form a unified concept of the integrated use of different wastewater treatment methods to form a resistant biological treatment stage of technological systems under the influence of such toxic factors as antibiotics and surfactants. The processes of mechanical treatment, ozonation, UV irradiation, and electrolytic anodic oxidation were implemented in an electrotechnological wastewater treatment facility. Wastewater treatment quality was determined by the concentration of nitrogen compounds in aqueous solutions according to the method of Lurie. Biodiagnostics of the investigated activated sludge via surfactant action was carried out at polyethylene oxide concentrations of 10, 30, and 50 mg/dm3. As a result of experiments on wastewater treatment after aquaculture, an improvement in the reduction of pollutants only by the indicator “nitrate concentration” was determined: by 20% after anodic oxidation, and by 15% after photolysis. At almost all surfactant concentrations studied, the activated sludge was not completely recovered, which was expressed in a decrease in its quantity and in the inability to aggregate flakes of activated sludge. The diameter of the growth retardation of the standard disk with antibiotic (amoxiclav) by the accumulative culture of activated sludge was 17.3 ± 2 mm at a concentration of 4 mg/dm3 and 31.3 ± 3 mm at a concentration of 6 mg/dm3. In the process of studying the state of the activated sludge’s biocenosis under the influence of such toxicants, several regularities were revealed. The directions of using combined approaches of water treatment and wastewater treatment were defined. The structural model of treatment facilities using aerobic and anaerobic bioprocesses together with advanced oxidative technologies was substantiated.

Superficial dye penetration of two conventional ionomers used as dental fissures sealants

Objective: This study aimed to evaluate surface dye penetration of two conventional glass ionomer cements (GIC), one of them a high viscous ionomer. Methods: 20 standard disk samples measuring 2 mm thick and 4 mm in diameter were made for each conventional GIC. The high viscous ionomer was used as the control (Group 1). Samples were embedded in wax and submitted to pH cycling for 7 days simulating a high cariogenic challenge in a kiln (37ºC). All samples were brushed with an extra-soft bristles infant toothbrush to mimic oral hygiene after exposure to a demineralizing solution for 6 hours. The samples were immersed in a 1% methylene blue solution for 2 hours at the end of cycling. The Mann-Whitney Rank Sum Test was used to analyze the difference between the two GIC. Results: All samples disclosed a superficial dye penetration of 0.6 to 1.5 mm depth. There was no statistical d ifference b etween t he G IC t ested ( p = 0.883). Conclusion: Both GIC tested in this study exhibited superficial dye penetration to depths of at least until their superficial third.

QPOs in compact binaries from small scale eruptions in an inner magnetized disk

Dwarf novæ (DNe) and low mass X-ray binaries (LMXBs) are compact binaries showing variability on time scales from years to less than seconds. Here, we focus on explaining part of the rapid fluctuations in DNe, following the framework of recent studies on the monthly eruptions of DNe that use a hybrid disk composed of an outer standard disk and an inner magnetized disk. We show that the ionization instability, that is responsible for the monthly eruptions of DNe, is also able to operate in the inner magnetized disk. Given the low density and the fast accretion time scale of the inner magnetized disk, the ionization instability generates small, rapid heating and cooling fronts propagating back and forth in the inner disk. This leads to quasi-periodic oscillations (QPOs) with a period of the order of 1000 s. A strong prediction of our model is that these QPOs can only develop in quiescence or at the beginning/end of an outburst. We propose that these rapid fluctuations might explain a subclass of already observed QPOs in DNe as well as a, still to observe, subclass of QPOs in LMXBs. We also extrapolate to the possibility that the radiation pressure instability might be related to Type B QPOs in LMXBs.

Antimicrobial Activity of Ethanolic and Methanolic Extracts of Urtica dioica, Mentha longifolia, and Bacteriocin Produced by Lactobacillus casei Against Antibiotic-Resistant Bacteria

Background: The increasing resistance of human microbial pathogens to the available antibacterial compounds is a significant threat, resulting in the search for new antibiotic resources such as plants and probiotics. Therefore, this study aimed to evaluate the antibacterial effect of ethanolic and methanolic extracts of Urtica dioica, Mentha longifolia, and bacteriocin purified from a probiotic bacteria using the standard disk diffusion method against some pathogenic strains. Materials and methods: Ethanolic/methanolic extract of U. dioica, M. longifolia, and bacteriocin from probiotic bacteria were prepared by the standard methods. The effect of different concentrations of the extracts on some antibiotic-resistant bacteria was evaluated using the standard disk diffusion method by measuring the diameter of the growth inhibition zone. Results: The disk diffusion test showed that the bacteriocin Lactobacillus casei had more growth inhibitory effects on the tested bacterial strains than the methanolic and ethanolic extracts of U. dioica and M. longifolia. Bacteriocin extract of L. casei exhibited significant antibacterial activity at the concentrations of 12 and 18 mg/mL (P≤0.05) against antibiotic-resistant bacteria, while a 12 mm zone of inhibition was observed in the concentration of 1.5 mg/mL against Salmonella enterica serovar Typhimurium (S. Typhimurium). Conclusion: According to the agar well diffusion method results, the bacteriocin producing L. casei has an extensive range of antibacterial spectrum against resistant bacteria. It can be used as an alternative to antimicrobia agents for the treatment of infections caused by resistant bacteria. It is suggested that in future research, the cytotoxicity of the extracts be evaluated in vitro/in vivo studies.

Discovery of a transient X-ray source Suzaku J1305−4930 in NGC 4945

We report the serendipitous discovery of a transient X-ray source, Suzaku J1305−4930, ∼3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku J1305−4930 was detected four times in July and August in 2010. The X-ray spectra are better approximated with a multi-color disk model than a power-law model. At the first detection on 2010 July 4–5, its X-ray luminosity was $(8.9^{+0.2}_{-0.4}) \times 10^{38}\:$erg s−1 and the temperature at the inner-disk radius (kTin) was 1.12 ± 0.04 keV. At the last detection with Suzaku on 2010 August 4–5, the luminosity decreased to $(2.2^{+0.3}_{-0.8}) \times 10^{38}\:$erg s−1 and kTin was 0.62 ± 0.07 keV. The source was not detected on 2011 January 29, about six months after the first detection, with a luminosity upper limit of 2.4 × 1038 erg s−1. We also find an absorption feature which is similar to that reported in Cyg X-1. Assuming the standard disk, we suggest that Suzaku J1305−4930 consists of a black hole with a mass of ∼10 $M_\odot$. The relation between the disk luminosity and kTin is not reproduced with the standard model of a constant inner radius but is better approximated with a slim-disk model.

Resistance Pattern of Extended Spectrum β-Lactamase Producing Gram-Negative Pathogens from Surgical Site Infections

There is an increasing resistance for drugs in first line of treatment for post-operative wound. It has imposed the practitioners the use of newer antibiotics. β-lactamase production is the most important mechanism of resistance to the penicillin and cephalosporins. The present study was undertaken with the objective of isolation of ESBL producing gram-negative pathogens from surgical site infections and to study their resistance pattern. A total number of 28 surgical hospitals were selected for the collection of post operative wound infection samples. The ESBL producing pathogens were detected by phenotypic screening and confirmatory methods as recommended by CLSI guidelines 2012. A standard disk diffusion technique for antimicrobial susceptibility testing was performed as recommended by clinical and laboratory standard institute (CLSI). The total number of ESBL producers was 141 (37.80 %) while the number of non-ESBL producers was 232 (62.20 %). The distribution of ESBL producing E. coli, Klebsiella species, Proteus species and Pseudomonas species was 74 (55.64%), 42 (6.20%), was 16 (22.22 %) and 09 (17.31 %) respectively. The ESBL producing isolates were highly resistant to Cephalosporin, Ampicillin, Ciprofloxacin, Gentamycin and Cotromoxazole while they were highly susceptible to Ceftazidime/Cluvanic acid, Piperacillin / Tazobactam, Imipenem and Meropenum. In conclusion, the present study shows the considerable occurrence of ESBL producers among the Gram-negative isolates from surgical site infections and their increasing multidrug resistance.

Recent pattern of antibiotic resistance in Staphylococcus aureus clinical isolates in Eastern India and the emergence of reduced susceptibility to vancomycin

PURPOSE: We aimed to determine the recent pattern of antibiotic resistance and assess the vancomycin susceptibility profile of clinical Staphylococcus aureus in view of emerging reports of vancomycin creep, reduced vancomycin susceptibility (RVS), including heterogeneous vancomycin-intermediate S. aureus (hVISA) and vancomycin-intermediate S. aureus, and vancomycin resistance in S. aureus isolates. MATERIALS AND METHODS: Consecutive, nonduplicate isolates of S. aureus between July 2015 and June 2016 were subjected to antimicrobial susceptibility testing using standard disk diffusion test or Etest as per the Clinical and Laboratory Standards Institute 2015. Detection of hVISA was done by glycopeptide resistance detection Etest according to the manufacturer's instructions in strains with vancomycin minimum inhibitory concentration of 1–2 μg/ml. RESULTS: A total of 284 S. aureus were obtained from pus (175, 61.6%), respiratory tract (31, 10.9%), urine (27, 9.5%), blood (25, 8.8%), body fluids (18, 6.3%), and catheter tips (8, 2.8%). 127 (44.7%) isolates were methicillin resistant, and 158 (55.6%) were multidrug resistant. High resistance was observed to penicillin (81.7%), erythromycin (62.3%), and ciprofloxacin (52.1%), whereas the resistance was low to gentamicin (5.3%), rifampicin (8.1%), and doxycycline (9.5%). Two hundred and fifty-one (88.3%) isolates were fully susceptible to vancomycin, whereas 33 (11.6%) demonstrated RVS. All were uniformly susceptible to linezolid, tigecycline, and daptomycin. CONCLUSIONS: A moderately high percentage of S. aureus isolates demonstrated RVS, which may limit its usefulness in methicillin-resistant isolates and may be associated with increased complications in methicillin-susceptible infections. In view of increasing glycopeptide resistance, the susceptibility status of vancomycin along with other antibiotics among clinical S. aureus isolates should be investigated periodically.

Stop Waiting for Tomorrow: Early Disk Diffusion—An Accurate Method for Antimicrobial Susceptibility Testing With Reduced Turnaround Time

Background Disk diffusion is a slow but reliable reference method for measuring antimicrobial susceptibility. Our objective was to improve the turnaround time for this method by reducing the culture incubation period prior to disk diffusion testing (referred to as early disk diffusion [eDD] testing). Methods Clinical isolates (n = 13) and quality control (QC) strains (n = 8) of bacteria, including 6 Staphylococcus aureus, 3 Enterococcus faecium, 3 Enterococcus faecalis, 3 Escherichia coli, 3 Pseudomonas aeruginosa, 2 Klebsiella pneumoniae, and 1 Enterobacter cloacae, were inoculated on blood agar by quadrant streaking and were incubated at 35○C for 6 hours (eDD6), 10 hours (eDD10), or 24 hours (standard [sDD]) before disk diffusion testing was set up in accordance with CLSI guidelines using Mueller Hinton Agar (Hardy Diagnostics) and clinically appropriate antimicrobial agents (total: 24). Experiments were performed sequentially in triplicate with zones measured by two independent readers. Results Examination of 6-hour blood agar plates showed limited growth in the first 1 to 2 quadrants while 10-hour growth plates had 4-quadrant growth and individual colonies in most cases. Despite limited growth on 6-hour plates, there were adequate bacteria to produce a 0.5 McFarland standard for disk diffusion testing for all 126 eDD replicates. Results were evaluable for 1,206 of 1,206 (100%) of eDD and 603 of 603 (100%) of standard disk diffusion (sDD). A comparison of early vs standard disk diffusion showed that eDD6 had 3 of 154 (1.9%) very major errors and 6 of 449 (1.3%) major errors, whereas eDD10 had no very major errors and 3 of 449 (0.7%) minor errors. Very major errors in eDD6 included a 1-mm difference between eDD6 and sDD for cefoxitin inhibition of S aureus as well as 4- and 6-mm differences between eDD6 replicates and sDD for nitrofurantoin inhibition of E cloacae. There was similar categorical agreement of eDD6 (96.7%) and eDD10 (96.7%) with sDD. Overall, there was a very good correlation of eDD6 (r2 = 0.98) and eDD10 (r2 = 0.99) with sDD. When grouping results by bacterial species, there was no more than 1-mm difference in median antimicrobial inhibition between eDD6, eDD10, and sDD. Of note, 5 of 7 bacterial species had the same median zone size when comparing eDD6 or eDD10 with sDD. There was also very little difference between early and standard methods when examining bacteria-drug combinations, with a similar zone size (difference in mode <2 mm) in 67 of 69 (97%) eDD6 and 66 of 69 (96%) eDD10 compared to sDD. Test results for QC isolates agreed with the CLSI recommended ranges in 97 of 99 (98%) eDD6, 97 of 99 (98%) eDD10, and 96 of 99 (97%) sDD. Conclusion Early disk diffusion testing is a simple and accurate method of antimicrobial susceptibility testing that can reduce time to results by as much as 18 hours with no additional cost.