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Urinary Tract Infections
New Potent, Broad-spectrum Treatments for Serious Urinary Tract Infections
a report by
Florian ME Wagenlehner,
1
W Weidner
1
and Kurt G Naber
2
1. Clinic of Urology and Paediatric Urology, Justus-Liebig-University, Giessen; 2. Technical University, Munich
Nowadays, antibiotic resistance plays an important role in the treatment comprise Escherichia coli, followed by Klebsiella spp., Pseudomonas
of serious complicated urinary tract infections (UTIs). The lower the spp., Proteus spp., Enterobacter spp. and Citrobacter spp. The
resistance rates against an antibiotic, the higher the survival of patients Gram-positive pathogens account for about 15–30% of the spectrum
with serious infections and UTIs. Therefore, substances with activity and comprise enterococci and staphylococci.
8–13
Nosocomial
against bacteria that harbour common resistance mechanisms are uropathogens are frequently subject to antibiotic pressure and cross-
increasingly important. However, widespread use of so-called reserved infection. Different species of uropathogens show distinct abilities to
antibiotics will eventually be a source of other multiresistant bacteria. develop antibiotic resistance.
Therefore, in any case, prudent use of antibiotics will be the best way to
ensure active antibiotic treatment in the future. Surveillance programmes such as the SENTRY study, the European
Study Group on Nosocomial Infections (ESGNI) and the Post-Exposure
UTIs are among the most prevalent microbial diseases, and their Prophylaxis (PEP) study revealed that, considering the total bacterial
financial burden on society is substantial. UTIs account for more than spectrum investigated, generally the aminopenicillins (with
100,000 hospital admissions each year, most often for cases of β-lactamase inhibitors) showed resistance rates of approximately 60%
pyelonephritis,
1,2
and they also account for at least 40% of all (respectively, 30%). Trimethoprim–sulfamethoxazole (TMP–SMZ)
hospital-acquired infections, which in the majority of cases are showed resistance rates of between 22 and 45%. Resistance to
catheter-associated.
3–5
ciprofloxacin was approximately 20–40%, to gentamicin 18–34%,
to ceftazidime 13–28%, to piperacillin/tazobactam 8–15% and to
Definition of Urinary Tract Infection imipenem 7–14%. Resistance in enterococci to vancomycin was
UTIs can manifest as bacteriuria, uncomplicated UTI with limited clinical between 0 and 5%.
8–13
It has been convincingly demonstrated that
symptoms or severe UTI – namely sepsis or severe sepsis – depending on severe infections have lower mortality rates when the empirical
localised or systemic extension. In 20–30% of all septic patients, the therapy has initially covered all causative bacteria.
14,15
This has been
infectious focus is localised in the urogenital tract.
6,7
confirmed in a small study for bacteraemic UTIs as well.
16
As a result,
broad-spectrum antimicrobial agents are increasingly being launched
Treatment of Serious Urinary Tract Infections in clinical studies.
Gram-negative species account for approximately 60–80% of the
bacterial spectrum of complicated and nosocomially acquired UTI and In all of the studies, increasing rates of antibiotic resistance were
found with specific species such as E. coli, P. aeruginosa, Klebsiella
spp., Enterobacter spp., enterococci and coagulase-negative
Florian ME Wagenlehner is a Consultant Urologist at the Clinic
of Urology and Paediatric Urology, Justus-Liebig-University,
staphylococci. Extended-spectrum β-lactamase-producing E. coli and
Giessen. He is a member of several societies, including the K. pneumoniae rapidly increase and may cause significant clinical
European Association of Urology (EAU) and the European
problems in the treatment of UTI.
17,18
Species producing
Society of Clinical Microbiology and Infectious Diseases
(ESCMID), and is Secretary of the German working group of
chromosomally encoded β-lactamases – although from the hygienic
the urinary tract infection guideline section. He gained his
point of view regarded as not as dangerous as plasmid-encoded
doctorate at the Technical University, Munich, in 1996.
β-lactamases – also pose significant clinical problems for empirical
antibiotic therapy. Carbapenems retained their activity in most of
Kurt G Naber is an Associate Professor of Urology at the
these uropathogens.
Technical University of Munich. Between 1975 and 2006 he
was Head of the Urological Clinic at St Elisabeth Hospital,
Straubing. He will be President of the International Society of
Carbapenems
Chemotherapy (ISC) for Infection and Cancer until 2009. Dr
Until recently, carbapenems were available only intravenously
Naber is the author of more than 540 scientific articles and is
on the Editorial Board of several journals. He is a member of
because they are unstable, especially in gastric or intestinal juice.
numerous societies, including the German, European and US Currently, the available carbapenems are classified by different
urological associations and infectious diseases societies, such
criteria. The classification by groups can follow the bacterial
as the Paul-Ehrlich Society (PEG), the German Society for Infectious Diseases (DGI) and the
European Society of Clinical Microbiology and Infectious Diseases (ESCMID). Dr Naber’s research
spectrum as in other antibiotic classes.
19
According to the
interests include urological infections, especially microbiology and pharmacokinetics of
bacterial spectrum, ertapenem is the sole representative of the first
antimicrobials for the treatment of UTI and prostatitis.
group, and imipenem and meropenem are the representatives of the
E: kurt.nabers@nabers.de
second group, which are currently licensed in Europe. Carbapenems
are active against Gram-positive and Gram-negative pathogens, as
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