Comamonas testosteroni Blood Stream Infection in A Patient with End-stage Renal Failure on Hemodialysis

We report for the first time from Jordan and probably Arab countries a very rare case of Comamonas testosteroni causing blood stream infection in a Sudanese patient with renal failure on hemodialysis whom was waiting for a living-related renal transplant. He was successfully treated with cefepime and had his transplant ten days into his treatment. Post-transplant he did well and was discharged home.






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The prevalence of Bovine tuberculosis and Brucellosis in cattle from selected herds in Dormaa and Kintampo Districts, Brong Ahafo region, Ghana

Background : Information on the prevalence of bovine brucellosis and tuberculosis in West African countries other than Nigeria had been scanty in literature. This study estimates the prevalence of brucellosis and bovine tuberculosis in cattle from selected herds in Dormaa and Kintampo Districts, Brong Ahafo region, Ghana.


Methods and Findings : The study involved testing of 444 cattle for tuberculosis and brucellosis using single comparative intradermal tuberculin and Rose Bengal plate tests respectively. Tuberculosis was recorded in 29 cattle giving overall individual cattle level tuberculosis prevalence of 6.5% and herd-level prevalence was 64.7±4.0% while the positive reaction to Rose Bengal was recorded in 13 cattle with overall individual cattle level brucellosis prevalence of 2.93%, the herd prevalence was 35.3±3.0%. The positive reactors to the diseases were significantly more in Dormaa district and cows than bulls. The infection was detected with increasing age, more between age 1 to 4 cattle in both diseases. The two diseases were detected in a >5year old cow giving an estimated prevalence of 0.23%.


Conclusions : Though the estimated prevalence of the two diseases was relatively low in the districts investigated, surveillance and prevention of the disease in Ghana may be warranted because of the continual unrestricted animal movement which might result in an increased transmission to humans.






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TRANSCRIPTOMIC STUDY REVEALS NEW PATHWAYS and GENES INVOLVED in Enterococcus faecalis V583 RESPONSE to a THERAPEUTIC DOSE of VANCOMYCIN

Title:Transcriptomic study reveals new pathways and genes involved in Enterococcusfaecalis V583 response to a therapeutic dose of vancomycin.Background: An enterococcalstrain carrying the VanB resistance type can become susceptible if impaired inother genes unrelated to the vanB operon. This fact alone illustratesthe lack of knowledge on the vancomycin mode of action. This antibiotic is stillusable to treat serious infections caused by multiresistant enterococcalstrains, but may not be so for long. This work was thus set up to gather a bodyof knowledge that can be used in the future to increase efficacy against bothvancomycin resistant (VRE) and susceptible enterococci (VSE). Methods and Findings: Microarrays were used to detect the genetic response of theVanB carrying strain Enterococcus faecalis V583 to a therapeutic dose(10 mg/ml) ofvancomycin. Besides the vanRS genes, two other two-component systemswere induced. The therapeutic dose of vancomycin was found to act as ananti-virulence agent, by turning-off the Fsr quorum-sensing system. Key regulators and metabolic enzymes,involved in trafficking carbon sources into glycolysis and isoprenoid synthesisand utilization, were also affected in order to support cell-wall synthesis.Also, cell-wall modification involving lipotheicoic acid synthesis, DNA repairand protein folding were highly responsive functions to the vancomycin dosetested.Conclusions:Overall, our results provideclues on the ability of a VRE strain to stand vancomycin and on the mode ofaction of the antibiotic. VRE response to a vancomycin therapeutic doseinvolves an intricate regulatory network and metabolic adjustment which isworth solving as it can help finding new targets to fight both VRE and VSEinfections.



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THE 13TH ANNUAL MEETING OF THE ROCKY MOUNTAIN VIROLOGY ASSOCIATION: CURRENT ADVANCES IN VIROLOGY AND PRION BIOLOGY IN THE ROCKY MOUNTAIN REGION


Virology and Prion biology has significant impacted basic research in molecularbiology, neurology and neuropathology, immunology, epidemiology,epigenetics and gene regulation, pathogenesis. In addition, many technicalimprovements ranging from trans-gene expression to high-through putscreening have their roots in virology/prion research. Translational medicinehas benefitted not only from the technical advances, but also from recentadvances in cell biology stemming from basic virology/prion biology. Withthis in mind, it would benefit those interested in translational medicine tokeep abreast of current topics in virology.
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Prescribing Antibiotics for pediatric dental patients in Jordan; knowledge and attitudes of dentists

Objective: The inappropriate use of antibiotic in treating children has been observedin the treatment of dental infections. Recent surveys reported that dentistsin several countries have modest knowledge about antibiotic prescribing. The aimof this study was to investigate the knowledge and attitude of a group of Jordaniandentists treating children towards antibiotic prescribing.Methods: A written questionnaire was distributed during a meeting of the JordanianSociety of Paediatric Dentistry. The questionnaire included questions aboutthe knowledge and attitudes of dentists toward dental antibiotic prescribing tochildren.Results: Amoxicillin was the most popular antibiotic (62.9%) to be prescribed bydentists treating children. A lesser percentage (29.7%) prescribe combination ofantibiotics, and around 37% prescribe antibiotics for duration longer than 5 days.Erythromycin was the most popular alternative to amoxicillin (77.8%) followed byclindamycin (22.2%). A number of antibiotics were prescribed for non-indicatedclinical conditions like pulpitis and gingivitis. More than 50% of the sample prescribedantibiotics for non-scientific reasons like the “need to delay treatment” and“sterilization not guaranteed”.Conclusion: There is a need to improve awareness of Jordanian dentists regardingantibiotic prescribing to children particularly in the aspects of type of antibiotic tobe used for patients allergic and non-allergic to penicillin, duration of prescribing,and clinical indications. Dentists also should be discouraged to prescribe antibioticsbased on non-scientific/social factors.



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Evaluation of Meropenem, Imipenem and Ertapenem Impregnated MacConkey Agar Plates for the Detection of Carbapenem Resistant Enterobacteriaceae

Background: Rapid detection of carbapenem resistant bacteria, in particular, members of the Enterobacteriaceae family (CRE), is of utmost importance for the management of infected or colonized patients.


Methods: Three carbapenems; meropenem, imipenem and ertapenem, with two different concentrations (0.5 m g/ml and 1.0 m g/ml), were impregnated in MacConkey agar. The carbapenem impregnated MacConkey agar plates; ([Mac-Mem], [Mac-Imp] and [Mac-Ert]), were then evaluated for the detection of carbapenem resistant Gram-negative bacteria in particular the bla KPC producing Enterobacteriaceae. The Limit of Detection (LOD) of the plates was determined after counting the colonies that grew on the plates after serial logarithmic dilutions of ten. Carbapenem resistant Gram-negative bacteria were prepared in normal saline, inoculated on the different plates and incubated at 35o C for 18-24 hours. The specificity and the shelf-life of the plates were determined by challenging the plates with six ESBL positive members of the Enterobacteriaceae family (K. pneumoniae, Salmonella species, Shigella species, E. coli, Proteus species and Citrobacter species) and one Enterobacter species with the bla AmpC phenotype . Finally, the MacConkey agar plates impregnated with 0.5 m g/ml meropenem were further challenged by incorporating them in the routine Caritas Baby Hospital active surveillance program for the detection of carbapenem resistant bacteria.


Results: Of the three carbapenems impregnated plates, Mac-Ert plates gave the lowest number of colony forming units (CFU’s) detected regardless of the concentration of the antibiotic used. This was followed by the Mac-Mem plates which showed an LOD of less than 200 CFU’s for most of the bla KPC positive bacteria tested at both antibiotic concentrations. The worst performance was noted for the Mac-Imp plate regardless of the antibiotic concentration used as a number of carbapenem resistant bacterial strains failed to grow on the plate. The Mac-Mem plates showed the best specificity as none of the ESBL and bla AmpC positive isolates grew on the plates at either antibiotic concentration tested after 18-24hours incubation in ambient air at 35o C. On the other hand, the Mac-Ert plates failed to inhibit the growth of the Citrobacter species tested at both antibiotic concentrations and the Proteus species tested at the 0.5µg/ml antibiotic concentration. The Mac-Imp plates showed poor specificity as both concentrations failed to inhibit the growth of the Proteus, Enterobacter and Citrobacter species evaluated after 18-24 hours incubation in ambient air at 35o C. Of all the plates tested, the 0.5 µg/ml Mac-Mem agar had the best shelf-life of up to one month at 4-8o C.


Conclusions: The high specificity and the good selectivity, in addition to the long shelf-life allowed the 0.5µg/ml Mac-Mem agar to be used as a cost effective selective medium for the isolation of carbapenem resistant Gram-negative bacteria, in particular the blaKPC producing members of the Enterobacteriaceae family.



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Isolation, heterologous expression and gene duplication of certain ribostamycin biosynthetic genes from Streptomyces ribosidificus NRRL B-11466

Abstract



Background


To elucidate the biosynthetic pathways of ribostamycin and related antibiotics, cloning, expression and functional determination of certain genes out of the respective gene clusters have to be carried out.


Methods and findings


Analysis of the respective antibiotic biosynthetic gene clusters showed that the RibN protein had a remarkable difference in its primary structure relative to NeoN, ParN, and LivN homologous proteins. In this study, the ribC from the ribostamycin biosynthetic gene cluster of Streptomyces ribosidificus NRRL B-11466, and the parN gene from the paromomycin biosynthetic gene cluster of Streptomyces rimosus subsp. paromomycinus NRRL 2455 were amplified using PCR, cloned into the cloning plasmid pUCPU21 producing pURC and pURCPN recombinant plasmids, respectively. RibC protein was expressed in E. coli JM109(DE3) under the control of T7 promoter. The expressed RibC protein was analyzed and shown to produce the functional protein 2-deoxy-scyllo-inosose synthase which catalyses the formation 2-deoxy-scyllo-inosose from glucose-6-phosphate. Alignment of RibN and its homologous proteins revealed a stretch of nonconserved amino acid sequence was detected at the positions from 185 to 261 in the RibN amino acid sequence as determined by multiple amino acid alignment sequences. Both ribC and parN were cloned into pUWL201PW shuttle vector producing pUWRC and pUWPN, respectively. The resulted recombinant plasmids were transformed into S. ribosidificus for the purpose of gene duplication and studying their influence on ribostamycin production.


Conclusion


RibC was successfully cloned, heterologous expressed in E. coli. The produced protein was biochemically proved to be involved in the synthesis of 2-deoxy-scyllo-inosose from Glucose-6-p. RibN was proved to have endogenous frame-shift mutation which was proposed to be reason for formation of ribostamycin as an end product. RibN was cloned into pUWL201PW shuttle vector as a prerequisite step for its influence on ribostamycin production.






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Archives of Clinical Microbiology