|Year : 2014 | Volume
| Issue : 2 | Page : 112-113
Complicated urinary tract infection caused by extended spectrum β-lactamase-producing Escherichia coli
KP Ranjan, Neelima Ranjan
Department of Microbiology, G. R. Medical College, Gwalior, India
|Date of Web Publication||15-Apr-2014|
K P Ranjan
Department of Microbiology, G. R. Medical College, Gwalior
|How to cite this article:|
Ranjan K P, Ranjan N. Complicated urinary tract infection caused by extended spectrum β-lactamase-producing Escherichia coli. Urol Ann 2014;6:112-3
A complicated urinary tract infection (UTI) is an infection of urinary tract associated with a condition, such as structural or functional abnormalities of the genitourinary tract or the presence of an underlying disease, which increases the risk of acquiring an infection or of failing therapy.  In the past few years, the number of complicated UTI due to resistant gram-negative bacteria has risen, mainly due to spread of extended spectrum β-lactamase (ESBL) bacteria which pose a significant therapeutic challenge. Although a broad range of pathogens can cause complicated UTI, Escherichia More Details coli remains the most common. 
ESBLs are typically plasmid-mediated clavulanate susceptible enzymes that hydrolyze penicillin, expanded spectrum cephalosporins, and aztreonam. These are most commonly derived from TEM or Sulfhydryl variable parents but the prevalence of CTX-M has also increased dramatically worldwide. Co-resistance to quinolones and aminoglycosides is common among ESBL producers. ESBLs belong to class A of Ambler classification and are primarily produced by the Enterobacteriaceae family of gram-negative organisms, in particular Klebsiella pneumoniae and E. Coli. Major risk factors for colonization or infection with ESBL-producing organisms are long-term antibiotic exposure, prolonged hospital stays, residence in an institution with high rates of third-generation cephalosporins use, and in whom invasive devices (urinary catheters, endotracheal tubes, and central venous lines) are present for a prolonged duration.  A variety of conventional laboratory methods are available to detect the presence of ESBL in an isolate, including double disc synergy, combination disc method, and specific ESBL E-tests. However, if the isolate is also producing an additional AmpC or metallo-β-lactamases (which are not inhibited by clavulanate), these methods will lose their sensitivity.  Also ESBL detection by conventional methods can be both technically difficult and time-consuming. Molecular analysis for genes coding ESBLs with polymerase chain reaction can be used in reference laboratories as quicker alternative to conventional methods.
In this study, author reports the incidence of ESBL-positive E. coli in complicated UTI. Out of the total 49 patients suffering from complicated UTI included in the study, 11 patients had E. coli infection and ESBL production was exhibited by 7, of these 11 E. Coli isolates (63.6%). All of these E. Coli isolates were highly resistant and showed sensitivity only to amikacin and carbapenems. Also all patients had received multiple antibiotic therapies in the previous months with quinolones or third-generation cephalosporins, a fact which can be held responsible for the high ESBL positivity and quinolone resistance among the isolates. Mahesh et al.  also reported E. Coli as the most common cause of complicated UTI and that 66.78% of the total E. Coli isolates were ESBL producer. Such studies point toward the rise and spread of ESBL-producing organisms in serious clinical infections. ESBL-producing organisms can spread easily within the hospital environment. Most commonly, the transient carriage of organism on the hands of healthcare workers is implicated in patient to patient spread. Environmental contamination is also a potential source with sinks, baths, and medical equipment such as bronchoscopes, blood pressure cuffs, and ultrasound gel all being reported as sources of infection.
There is no doubt that ESBL-producing infections are of grave concern to the medical world. They are associated with an increased morbidity and mortality and can be difficult and time-consuming to identify. Treatment strategy for complicated UTI includes appropriate antimicrobial therapy and the management of the urological abnormalities. Quinolones may be regarded as the treatment of choice for complicated UTI due to ESBL-producing organisms, if there is no in vitro resistance to quinolones. However, due to concern of increasing resistance, the empirical use of quinolones to treat these infections is generally not recommended.  Another antibiotic option for treating complicated UTI is the carbapenems which are regarded as drug of choice of severe infections with ESBL-producing organisms.  Antimicrobial therapy for at least 7-14 days is usually recommended for complicated UTI. 
ESBL was first identified in 1980 and has evolved greatly over the last 30 years.  But similar evolution has not taken place in the development of newer, effective antibiotics against multi-drug resistant bacteria. This makes infection control and antibiotic stewardship programs an integral part of our weapons in the war against these resistant pathogens. Hand hygiene, an adequate level of nursing staff especially in intensive care units and judicial, prudent use of antibiotics to avoid selection pressure must be strictly followed. At institutional level, regular monitoring of local surveillance data of the common infecting pathogens along with screening and confirmation of ESBL producers is of paramount importance in controlling this rise in multi-drug resistant pathogens.
| References|| |
|1.||Kumazawa J, Matsumoto T. Complicated UTIs. In: Bergan T, editor. UTIs. Infectiology. Vol 1. Basel: Karger; 1997. p. 19-26. |
|2.||Nicolle LE. A practical guide to the management of complicated urinary tract infection. Drugs 1997;53:583-92. |
|3.||Paterson DL, Bonomo RA. Extended-spectrum beta-lactamases: A clinical update. Clin Microbiol Rev 2005;18:657-86. |
|4.||Drieux L, Brossier F, Sougakoff W, Jarlier V. Phenotypic detection of extended-spectrum β-lactamase production in Enterobacteriaceae: Review and bench guide. Clin Microbiol Infect 2008;14:90-103. |
|5.||Mahesh E, Ramesh D, Indumathi VA, Punith K, Raj K, Anupama H. Complicated urinary tract infection in a tertiary care center in South India. Al Ameen J Med Sci 2010;3:120-2. |
|6.||Carson C, Naber KG. Role of fluoroquinolones in the treatment of serious bacterial urinary tract infections. Drugs 2004;64:1359-73. |
|7.||Bloomfield P, Hodson EM, Craig JC. Antibiotics for acute pyelonephritis in children (Cochrane Review) In: The Cochrane Library, Issue 3. Chichester, UK: John Wiley and Sons, Ltd; 2004. |
|8.||Dhillon RH, Clark J. ′ESBLs: A Clear and Present Danger?′, Crit Care Res Pract 2012;2012:625170. |