Medical Journal of Dr. D.Y. Patil Vidyapeeth

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 8  |  Issue : 5  |  Page : 585--589

Occurrence of catheter-associated urinary tract infection in critical care units


Chanda R Vyawahare, Nageswari R Gandham, Rabindra Nath Misra, Savita V Jadhav, Neetu S Gupta, Kalpana M Angadi 
 Department of Microbiology, Dr. D. Y. Patil Medical College, Pimpri, Pune, Maharashtra, India

Correspondence Address:
Chanda R Vyawahare
Department of Microbiology, Dr. D. Y. Patil Medical College, Pimpri, Pune, Maharashtra
India

Abstract

Background: Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection. The etiological agents of which may be varied. Advancing age, debilitation, diabetes mellitus, duration of catheterization are the risk factors. Complications include prostatitis, epididymitis, cystitis, pyelonephritis and septicemia in high-risk patients, adding to hospitalization and morbidity. With this background the present study was undertaken Objectives: (1) To identify microbial pathogens associated with urinary tract infection (UTI) in catheterized patients from Intensive Care Units (ICU) (2) to determine the susceptibility pattern of these isolates to antimicrobial agents (3) to determine the effect of days of catheterization and UTI. Materials and Methods: Consecutive urine samples of 345 catheterized patients admitted in ICUs were included in the study. They were processed by standard microbiological procedures. Isolated organisms were speciated, and antibiotic susceptibility performed as per standard guidelines. Results: From the 345 urine samples of catheterized patients, 205 showed no growth and were found to be sterile. Bacterial growth was seen in 69 patients and fungal growth in 50 patients. Among the bacterial isolates, Escherichia coli were isolated in 39, followed by Klebsiella spp. 14. The other isolates included Pseudomonas spp., Group D streptococci and methicillin-resistant Staphylococcus aureus. In the fungal isolates, Candida glabrata was the most common isolate. High resistance was seen among Klebsiella isolates (nalidixic acid-86% and cefotaxime-86%). Conclusion: Development of CAUTI is common in critically ill patients. Emphasis should be placed on good catheter management and reducing the duration of catheterization rather than prophylaxis in order to reduce the incidence of catheter-related UTI. Culture and susceptibility testing play a vital role in the management if UTI occurs.



How to cite this article:
Vyawahare CR, Gandham NR, Misra RN, Jadhav SV, Gupta NS, Angadi KM. Occurrence of catheter-associated urinary tract infection in critical care units.Med J DY Patil Univ 2015;8:585-589


How to cite this URL:
Vyawahare CR, Gandham NR, Misra RN, Jadhav SV, Gupta NS, Angadi KM. Occurrence of catheter-associated urinary tract infection in critical care units. Med J DY Patil Univ [serial online] 2015 [cited 2019 Dec 15 ];8:585-589
Available from: http://www.mjdrdypu.org/text.asp?2015/8/5/585/164974


Full Text

 Introduction



The indications of urinary catheterization in the management of critically ill patients are many. Various micro-organisms are introduced into the urethra while the catheter is inserted through the sheath of exudates surrounding the catheter or intraluminally from the tube or collection bag. Infection mainly occurs due to colonization and device biofilm formation. Bacteriuria and candiduria develop in up to 25% of patients requiring urinary catheter for more than 7 days.[1]

Hospital-acquired urinary tract infection (UTI) are the most frequent nosocomial infection.[2] Many of these organisms are part of patients endogenous bowel flora, but they can also be acquired from the hospital environment.[3] They are responsible for almost 20-30% of nosocomial infection in medical or surgical Intensive Care Unit (ICU).[4],[5] Various hospital-based studies have reported threefold increase in mortality due to nosocomial UTI.[6],[7] Catheter-associated UTI (CAUTI), increases hospitalization, mortality and also the cost.[8],[9]

With this background, the present study was undertaken to find out the incidence of UTI in catheterized patients from our tertiary care hospital.

Objective of the study

To find out the incidence of UTI in catheterized patients.To identify the microbial pathogens associated with bacteriuria and UTI in catheterized patients.To determine their susceptibility pattern to commonly used antimicrobial agents for prophylaxis and empiric therapy of CAUTI in patients on indwelling urinary catheters from our tertiary care hospital.

 Materials and Methods



The study was carried in Department of Microbiology of a PG and UG teaching tertiary care hospital in Western Maharashtra. 345 consecutive urine samples of the patients with indwelling urethral catheter inserted under aseptic condition for various Medical and surgical conditions were included in the study. Samples were collected over a period of 1-year from January 2012 to December 2012 from patients admitted to the medicine and surgical ICU.

Specimen collection

Prior to catheter change or removal from each patient, urine sample were collected aseptically using a sterile needle and syringe from the distal edge of catheter tube into the sterile universal container and transported to the microbiology laboratory for analysis with minimum delay. Patient with symptoms of UTI prior to the catheterization were excluded.

Microbiology

The samples were processed by the routine standard laboratory procedure. This included microscopy, culture identification and antibiotic susceptibility testing. Urine microscopy was performed on centrifuged catheter urine specimen. Culture was set up on Cysteine Lactose Electrolyte Deficient Agar for isolating all kind of urinary pathogens; in few cases we used blood agar and Macconkey agar. Semiquantitative method of urine culture was followed. A sterile calibrated wire loop was used to deliver a loopful (0.01 ml) of urine onto each culture media. All the culture plates were incubated at 37°C aerobically for 18-24 h. All the culture positive isolates were identified by their colony morphology and gram stain and characterized biochemically for species identification. Isolate suggestive of the yeast were subcultured on sabouraud's dextrose agar. Further identification was done by demonstration of germ tube; sporulation on cornmeal agar, sugar fermentation and assimilation, CHROME agar and confirmation is done by YST ID cards using Vitek 2 system (Biomerieux, Vitek 2C). Antimicrobial susceptibility testing was done by Kirby-Bauer disk-diffusion method on Muller-Hinton agar.

 Results



A total 345 urine sample from catheterized patients were obtained. 271 (79%) samples were from medicine ICU and 74 (21%) were from surgical ICU [Figure 1]. Of the total 345 patients 200 (58%) were male and 145 (42%) were female patients [Figure 1].{Figure 1}

Coming to microscopic examination, out of 345 urine samples, 130 samples showed the evidence of pus cells and or micro-organisms.

Following the culture of 345 urine samples from catheterized patients 205 (59%) was sterile. Culture showed bacterial growth in 69 (20%) of patients while in 50 (14%) of patients it showed the fungal growth. In 21 (7%) of cases the polymicrobial growth was found. This could have been due to improper collection of the urine sample. These were advised a repeat urine sample. Of these 15 samples were received again, on processing they were found to be sterile [Table 1].{Table 1}

Off the 69 bacterial isolates, E. coli was isolated in 39 (57%) cases and found to be most common. This was, followed by the Klebsiella spp. in 14 (20%) cases, Pseudomonas spp. in 5 (7%) cases. Other Gram-negative bacteria such as Enterobacter, Citrobacter were found in 4% cases. Gram-positive bacteria like Group D streptococci were identified in 6 (9%) cases while methicillin-resistant Staphylococcus aureus isolated from 2 (5%) cases [Table 2].{Table 2}

Coming to the fungal isolates, 50 (14%) cases showing fungal yeast growth. Candida spp. was the most common. Non-albicans Candida isolated more commonly than Candida albicans. Candida glabrata was isolated from 20 (40%) of cases, followed by C. albicans 18 (36%); Candida tropicalis 7 (14%), Candida parapsilosis 2 (4%). We also isolated Trichosporon spp. from 3 (6%) cases, all of these were found to be Trichosporon asshii [Table 3].{Table 3}

The table shows that the incidence of UTI was significantly higher as the days of catheterization increased [Table 4].{Table 4}

In vitro, antibiotic susceptibility pattern of Gram-negative and Gram-positive organism are summarized in [Table 5] and [Table 6]. It is found that there is high resistance to commonly used antibiotics for both Gram-positive and Gram-negative organisms, however imipenem (95% sensitivity) and combination of ceftazidime and tazobactam (82% sensitivity) appears to be effective.{Table 5}{Table 6}

 Discussion



Urinary catheter is inserted in more than 5 million patients in Emergency critical care hospital settings and extended care facilities. Therefore, these are at increased risk for CAUTI and its related sequelae. Worldwide per urethral catheter is identified as single most important predisposing factor for UTI. Catheter may serve as portal of entry for the pathogen if not aseptically inserted.[10],[11] In healthy patients, catheter-associated colonization is usually asymptomatic, which resolves spontaneously after the removal of the catheter. In susceptible patients, colonization persists and leads infection. The complication of which could be such as prostatitis, epididymitis, cystitis, pyelonephritis and septicemia due to Gram-negative bacteremia particularly in high-risk patients.[12]

The etiology of UTI is varied. Infection is caused by a variety of pathogens including E. coli, Klebsiella, Proteus, Enterococci, Pseudomonas, Enterobacter and Candida. Many of these pathogens are part of patients own flora but can be acquired by cross contamination from other patients or hospital personnel or by exposure to contaminated solutions or nonsterile equipment.[3]

Further CAUTI is most common cause of nosocomial infection.[13],[14],[15] It also extends the hospital stay and adds to the direct cost of acute care hospitalization. It is associated with increased mortality. Study by Platt et al. and Kunin et al. suggested that nosocomial CAUTI are associated with substantially increased institutional death rates.[9]

In our study among the catheterized patients in ICU, infection found in 41% of patients, this is low as compared to the Karina et al. study,[16] which recorded incidence of catheter-related UTI as 51.4% while it is comparable with study by Mulhall et al. which reported a 44% incidence.[17]

Several risk factors have been cited to be associated with catheter-related UTI;[18] these include advanced age, debilitation, postpartum state, etc.[12],[19] As advancing age is one of the predisposing host factor for development of CAUTI, the largest age group in our study included between 40 and 60 years of age (41.4%) while 30% of the patients were above the 60 years of age [Table 1]. Female gender is another significant risk factor, concurring with the result of other investigators. The increased risk among women is probably due to anatomic makeup, causing an easier access of the perineal flora to the bladder along the catheter as it traverses the shorter female urethra.[20] However, in our study males were predominantly affected. This might be due to multiple factors. A higher number of male samples as compared to female samples received and male are prone to obstructive urinary lesion especially from benign prostate hypertrophy, Ca prostate and stricture associated with advanced age. 12% of the patients from our study were associated with preexisting chronic condition such as Diabetes Mellitus. Study by Makhi et al.,[21] Platt et al. states a relative risk of 2.2-2.3 associated with this condition and Platt et al. also documented the presence of diabetes mellitus as a risk factor in their multivariate analysis.[22] An increased prevalence of the perineal colonization by potential pathogens and ability of urine of some diabetics to support microbial growth are the two possibilities linked with the same. Prolonged catheterization is one of the significant risk factors for the development of UTI.[20] In the present study, the rate of development of UTI was higher as the duration of catheterization increased. This is similar to the Taiwo and Aderounmu study.[23] This rate increased up to 75% after 1-week of catheterization [Table 4]. This rate is less than Taiwo and Aderounmu study.[23]

The most common bacterial pathogen isolated in our study was E. coli 39 (57%), followed by Klebsiella spp. 14 (20%), Pseudomonas spp. 5 (7%). Among the Gram-positive pathogens, Group D streptococci (Enterococci) 6 (9%) found to be most common, followed by Methicillin-resistant S. aureus 2 (3%). Other Gram-negative pathogen like Enterobacter, Citrobacter were isolated from 3 (4%) of cases.

In a study by Taiwo and Aderounmu[23]Klebsiella spp. (36%) were the most common pathogen, followed by Pseudomonas (27%), E. coli (20%), S. aureus (10%), Proteus mirabilis (3%), C. albicans (3%) and CONS as (1.6%). Most of the studies like Selden et al. 1971, McLeod 1958, Oni et al. 2003 found the similar pattern of isolation.[3],[24]

However, study by Karina et al.[16] found a similar pattern like the present study. They found E. coli the most common pathogen (27) followed by Klebsiella spp. (26%), Pseudomonas (8%). Among the Gram-positive organisms, Enterococcus (9%), followed by CONS and S. aureus were reported by that study.

In vitro antibiotic susceptibility pattern of the isolates showed the high level of resistance to commonly used drugs for UTI such as gentamicin (67.2%), norfloxacin (79.2%), nalidixic acid (81.1%), ceftazidime (65.5%), cefotaxime (92.4%) and amikacin (80%). The highest resistance was seen among the Klebsiella isolates (nalidixic acid-86%, cefotaxime-86%). The high resistance rate among the isolates observed in our study may be part due to the design of our study as it involved patients from ICUs. These patients generally undergo various empiric antimicrobial regimens and are, therefore, prone to develop infections by resistant pathogens.

Candidial infections of urinary tract are strongly associated with urinary catheterization.[11] In our study, Candidial infection was found in 14% of cases. Trichosporon spp. also identified in some cases; which is again one of the common causes of nosocomial UTI. Study by Makhi et al. of microbial pathogen causing nosocomial CAUTI in US acute care hospital, Candida was isolated in 9% of total isolates while in ICU this rate was 25%.[25]

In our study, non-albicans Candida found to be more common than C. albicans. C. glabrata was isolated from 40% cases, followed by C. albicans (36%), C. tropicalis (14%), C. parapsilosis (4%) and Trichosporon spp. (6%). One Indian study was conducted in 70 consecutive catheterized candiduria patients. Of 100 isolates of Candida spp. C. albicans was found in 71.4% and out of non-albicans Candida spp. C. tropicalis was the major isolate (52.9%).[26] In another prospective multicentre study by Kauffman et al. out of 861 hospitalized patients with funguria C. albicans was found in 52% and C. glabrata in 16%.[27]

 Conclusion



The urinary tract of catheterized patients is highly susceptible to severe infection. This infection is associated varied microbiological etiology. Antibiotic sensitivity pattern of the pathogen involved is also low. This along with existing underlying condition increases hospitalization, medication, morbidity and also adds to the financial burden. Therefore, it is imperative to carry out microbiological testing to determine etiology and ascertain effective antibiotics. Emphasis should also be made on reducing the duration of catheterization in order to reduce the incidence of catheter-related UTI. Hospital-wide surveillance program and appropriate catheter care protocols should be developed and implemented from evidence-based protocol.

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