Category Archives: AMM 2014, Volume 60, Number 3

Etiology of Bacteremic Syndromes and Bacterial Susceptibility of Blood Culture Isolates in a Romanian County Hospital

DOI: 10.2478/amma-2014-0018

Aim: To present the etiology of bacteremic syndromes and antibiotic susceptibility of blood culture isolates from a Romanian county hospital, as well as their distribution within different wards.
Methods: We retrospectively analyzed the blood culture data collected from patients hospitalized in the County Emergency Clinical Hospital of Tirgu Mures over a period of two years. We followed aspects regarding the identified bacterial species, their distribution by sex, age groups and wards, the spectrum of resistance to antibiotics and main resistance phenotypes.
Results: Most positive samples came from ICU, nephrology and urology. The most isolated bacteria were coagulase-negative staphylococci, Escherichia coli, and Staphylococcus aureus. All isolates showed a high resistance to most classes of antibiotics, staphylococci being susceptible to glycopeptides, oxazolidinones and glycylcyclines, and the enterobacteria to aminoglycosides and carbapenems. The resistance in non-fermentative bacilli exceeded 80% to most classes of antibiotics. The methicillin-resistance was 36% for coagulase-negative staphylococci and 82% for Staphylococcus aureus; the percentage of extended-spectrum beta-lactamase producing strains was 30%.
Conclusions: The etiology of bacteremic syndromes is specific to the ward profile, the Staphylococcus spp. being primarily isolated from wards where invasive procedures are frequently performed, while the enterobacteria from urology and nephrology wards. The level of antibiotic resistance is higher in surgery and ICU wards, with also higher percentage of resistance phenotypes than in medical wards.

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The UV and IR Comparative Spectrophoto-metric Study of Some Saturated and Lacunary Polyoxometalates

DOI: 10.2478/amma-2014-0017

Objectives: The polyoxometalates are a class of inorganic compounds with controllable shapes and sizes, and with excellent properties that make them attractive for various applications. This study is aimed at the comparative UV and IR spectra of Keggin type polyoxometalates.
Methods: Compounds under (UV and IR) investigations were divided into several groups to highlight similarities between compounds or classes of compounds for the same category. There are four types of saturated Keggin structures and six lacunar compounds included in this study. The study begins with the UV investigations on aqueous solutions with 10-5 M concentration for these compounds. IR spectra were recorded as KBr pressed pellets.
Results: The UV spectras presents large strong peaks between 185–195 nm corresponding to W = Od bonds, between 251–268 nm for W-O-W bridge bonds, depending on heteroatom types (As, Sb). The unsaturated cryptand ligand having Co2+ coordinated presents the most intense peak, due to the involvement of oxygen atoms from terminal W = Od coordinative bonds with high electronic densities in coordination of W-O-Co bond. The IR spectra present many peaks that are associated as follows: for terminal bonds W = Od, 955–970 cm-1; for W-O-W bridging bonds, 790–910 cm-1; for W-O-As/Sb bonds to heteroatom, 690–760 cm-1. Vibrations of the bonds between heteroatoms and oxygen (As/Sb-O) appear around 620–660 cm-1.
Conclusions: Similarities appear from the recorded spectra, between compounds of the same class, by category association. Very fine displacements of peaks that occur explain the influence of heteroatoms, addenda atoms or coordinated cations.

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Mirror, Mirror on the Ward

  1. Germs, ironically nicknamed “bugs” continue to be our concern, for they are a real threat. But when it comes for “bad bugs”, what are we going to do?
    Adrian Man et al studied the etiology of bacteriemic syndromes and bacterial susceptibility of blood culture isolates in a Romanian county hospital, namely, the County Emergency Clinical hospital of Tîrgu Mureș, Romania. They analyzed for three years all the blood cuture isolates [1].
    For any speciality besides microbiology, the process of understanding the general picture of microbiological results is painful. Denominations change, fresh insights into the bugs’ metabolism are paramount, bacteria seem to be more inteligent than predicted. Thus a whole arsenal has to be used to defeat bugs, strategies were developed, even the media and the patients are very sensitive to “killer bugs”.
    The workload to come up in time with reliable results seems to be considerable. Useful results mean for me: a result you can trust discriminating contamination from infection and information received within short time (better in less then 6 hours from admission). This could make a difference in outcome.
    When looking at the reported results, we learn that:
    1.The rate of blood culture positivity is 8%, which is quite low compared to other reports [1].
    2.For blood cultures, discrimination between contamination and etiological involvement is “still a problem” [1].
    For the severe septic patient, lack of reliable results as decribed is a real challenge. While contamination needs not to be treated with antibiotics, infection on the contary, requires target oriented medication. Only that the target is blurred. One can see it in 8% of the blood cultures, and less than this figure has an evidence-based suppport. Thus roughly >90% of the septic patients are exposed to empiric antimicrobials based on suspicions or on previously described local epidemiologic patterns.
    At the end of the day we can get a delayed bacterial result that cannot explain the critical condition of the patient. The identified germ may be a “bad bug”, still an epiphenomenon to a patient with multiple system organ failure of onother origin then septic.
    Bacterial results from blood culture imply a disproportionate workload for maginal benefits. Should we give up then to attempt bug identification, or should we reconsider our practcie? I have no doubts that strict adherence to sampling and handling blood protocols is mandatory. Otherwise, we will continue to escalate misunderstandings between microbiologists and clinicians. These snapshots of blood culture results will continue to be of limited use, a genuine waste of means. And yes, please handle everything with clean hands!