Expression stability of six housekeeping genes: a proposal for resistance gene quantification studies of Pseudomonas aeruginosa by real-time quantitative RT-PCR

Constantly expressed genes are used as internal controls in relative quantification studies. Suitable internal controls for such studies have not yet been defined for Pseudomonas aeruginosa. In this study, the genes ampC, fabD, proC, pbp-2, rpoD and rpoS of P. aeruginosa were compared in terms of expression stability by real-time quantitative RT-PCR. A total of 23 strains with diverse resistance phenotypes were studied. Stability of expression among the housekeeping genes was assessed on the basis of correlation coefficients, with the best-correlated pair accepted as being the most stable one. Eventually, proC and rpoD formed the most stable pair (r = 0.958; P < 0.001). Next, in four ciprofloxacin-selected nfxC-like mutants, levels of oprD, oprM and oprN mRNA were compared with those of their wild-type counterparts. The comparison was made after correcting the raw values by the geometric mean of the internal control genes proC and rpoD. The level of oprN mRNA was significantly up-regulated, while the oprD gene was down-regulated (although this difference was statistically insignificant), in the mutants. This expression pattern was consistent with that of the expected expression profile of nfxC-type mutants; this experiment therefore ends further support to the use of proC and rpoD genes simultaneously as internal controls for such studies

Genetic and enzymatic properties of metallo-beta-lactamase VIM-5 from a clinical isolate of Enterobacter cloacae

A VIM-5-producing Enterobacter cloacae isolate (EDV/1) was identified in a collection of clinical strains stored before 2002. The gene, blav(VIM-5), was located on a 2,712-bp BamHI-HindIII fragment of a 23-kbp (approximately) nonconjugative plasmid (pEDV5) in a class 1 integron as a single gene cassette

A conceptual methodology for estimating embodied carbon emissions of buildings in Sri Lanka

The reduction of whole building life cycle carbon requires equal attention on both operational carbon (OC) and embodied carbon (EC). Regardless of that, the Sri Lankan building sector concentrates mainly on reducing OC. The importance of reducing EC is yet to be fully realised. Therefore, there an opportunity exists to encourage research community, practitioners and policy makers associated with Sri Lankan building sector regarding EC reduction. The main drive towards EC reduction is estimation or assessment, as without this, it is impossible to realise the extent to how much is needed to be reduced. Even though, EC estimation process has been well developed and documented over the last years, it is yet a challenging process to Sri Lanka due to many difficulties such as difficulty in setting up a suitable estimation scope, unavailability of an up to date country-specific EC coefficient database for building materials and time consuming and work intensive nature of the estimation procedure due to unavailability of a suitable estimation tool. To deal with these challenges, initially it requires to establish a conceptual EC estimation methodology appropriate to the Sri Lankan building context. Accordingly, this study developed an EC estimation methodology based on the Life Cycle Assessment (LCA) approach; setting up the scope, performing EC coefficient inventory analysis and undertaking EC estimation and interpretation. Subsequently, the developed methodology was verified in terms of its applicability using a proposed commercial building in Sri Lanka. As a further study, it is intended to develop a statistical tool to estimate EC during design stage of commercial buildings in Sri Lanka conforming to this methodology

A national survey of surgical antibiotic prophylaxis in Turkey

OBJECTIVE: To assess the quality of antibiotic prophylaxis for clean and clean-contaminated elective surgical procedures

Neurobrucellosis: Results of the Istanbul Study

No data on whether brucellar meningitis or meningoencephalitis can be treated with oral antibiotics or whether an intravenous extended-spectrum cephalosporin, namely, ceftriaxone, which does not accumulate in phagocytes, should be added to the regimen exist in the literature. The aim of a study conducted in Istanbul, Turkey, was to compare the efficacy and tolerability of ceftriaxone-based antibiotic treatment regimens with those of an oral treatment protocol in patients with these conditions. This retrospective study enrolled 215 adult patients in 28 health care institutions from four different countries. The first protocol (P1) comprised ceftriaxone, rifampin, and doxycycline. The second protocol (P2) consisted of trimethoprim-sulfamethoxazole, rifampin, and doxycycline. In the third protocol (P3), the patients started with P1 and transferred to P2 when ceftriaxone was stopped. The treatment period was shorter with the regimens which included ceftriaxone (4.40 +/- 2.47 months in P1, 6.52 +/- 4.15 months in P2, and 5.18 +/- 2.27 months in P3) (P = 0.002). In seven patients, therapy was modified due to antibiotic side effects. When these cases were excluded, therapeutic failure did not differ significantly between ceftriaxone-based regimens (n = 5/166, 3.0%) and the oral therapy (n = 4/42, 9.5%) (P = 0.084). The efficacy of the ceftriaxone-based regimens was found to be better (n = 6/166 [3.6%] versus n = 6/42 [14.3%]; P = 0.017) when a composite negative outcome (CNO; relapse plus therapeutic failure) was considered. Accordingly, CNO was greatest in P2 (14.3%, n = 6/42) compared to P1 (2.6%, n = 3/ 117) and P3 (6.1%, n = 3/ 49) (P = 0.020). Seemingly, ceftriaxone-based regimens are more successful and require shorter therapy than the oral treatment protocol

Efficacy and tolerability of antibiotic combinations in neurobrucellosis: Results of the Istanbul study

PubMed ID: 22155822No data on whether brucellar meningitis or meningoencephalitis can be treated with oral antibiotics or whether an intravenous extended-spectrum cephalosporin, namely, ceftriaxone, which does not accumulate in phagocytes, should be added to the regimen exist in the literature. The aim of a study conducted in Istanbul, Turkey, was to compare the efficacy and tolerability of ceftriaxone-based antibiotic treatment regimens with those of an oral treatment protocol in patients with these conditions. This retrospective study enrolled 215 adult patients in 28 health care institutions from four different countries. The first protocol (P1) comprised ceftriaxone, rifampin, and doxycycline. The second protocol (P2) consisted of trimethoprim-sulfamethoxazole, rifampin, and doxycycline. In the third protocol (P3), the patients started with P1 and transferred to P2 when ceftriaxone was stopped. The treatment period was shorter with the regimens which included ceftriaxone (4.40 ± 2.47 months in P1, 6.52 ± 4.15 months in P2, and 5.18 ± 2.27 months in P3) (P = 0.002). In seven patients, therapy was modified due to antibiotic side effects. When these cases were excluded, therapeutic failure did not differ significantly between ceftriaxone-based regimens (n = 5/166, 3.0%) and the oral therapy (n = 4/42, 9.5%) (P = 0.084). The efficacy of the ceftriaxone-based regimens was found to be better (n = 6/166 [3.6%] versus n = 6/42 [14.3%]; P = 0.017) when a composite negative outcome (CNO; relapse plus therapeutic failure) was considered. Accordingly, CNO was greatest in P2 (14.3%, n = 6/42) compared to P1 (2.6%, n = 3/117) and P3 (6.1%, n = 3/49) (P = 0.020). Seemingly, ceftriaxone-based regimens are more successful and require shorter therapy than the oral treatment protocol. Copyright © 2012, American Society for Microbiology. All Rights Reserved