BACTERIURIA IN CATHETERIZED PATIENTS OF GYNECOLOGY WARD

M. Sharifi, MD

Qazvin University of Medical Sciences, Qazvin, Iran

  • Abstract

    Background- Urinary tract infection is one of the most common forms of nosocomial infection and urinary catheterization is the most frequent predisposing factor. These infections cause considerable morbidity and mortality and insert a great financial burden on the medical care system. This study was performed to determine the incidence of catheter-associated bacteriuria, to isolate the ethilogic organisms, and to assess their sensitivity to eleven most frequently prescribed antibiotics in Iran.
    Methods-Two urinary specimens were taken from the catheters of 146 patients admitted to the gynecology ward who carried an indwelled urinary catheter for >12 hours. The first specimen was taken at the time of catheterization and the second was taken after 72 hours.
    Results- Of 146 patients, 37 (25%) had a positive culture from which 40 different strains were isolated. Ninety percent of the strains belonged to Klebsiella pneumoniae, Enterobacter cloacae, and Proteus mirabilis. All of these strains were sensitive to amikacin and nalidixic acid. The sensitivity to gentamicin and tobramicin was 58%. All of the isolates were resistant to all other 7 antibiotics.
    Conclusion-The current antimicrobial regimen used in the hospital must be revised.

    Keywords · Gynecology · urinary catheter · enterobacteriaceae · infection · nosocomial

    •

    Introduction

    Urinary tract infection (UTI) is the most common nosocomial infection1,2 with catheterization constituting the most frequent cause.3 Eighty percent 1 and in another study all of nosocomial UTI’s 4 were associated with Follie catheter. There is also a positive correlation between the prevalence of UTI and female gender.5 In spite of a change from open to closed drainage systems, more than 30% of catheterized patients develop UTI2,6 but many remain asymptomatic7. Nosocomial infections associated with urinary catheter may increase the mortality rate up to 3 times.7 These infections have also a considerable financial burden.8

    In the current study the causative organisms for catheter-associated UTI in a gynecology ward in Kermanshah, West of Iran were determined and their sensitivity to commonly used antimicrobial agents evaluated.

    Material and Method

    This study was carried out in an OB/Gyn Center in Kermanshah, Western Iran. All patients had undergone either cystocele-rectocele perineorrhaphy or hysterectomy. Patients with a fixed catheter for 72 hours were included in the study. Exclusion criteria were discontinuing the catheter before 72 hours, discharge from hospital, or presence of infection as indicated by an active first sample urine.

    Two specimens were taken from each patient; one at the time of catheterization and another after 72 hours. The specimens were transferred immediately to laboratory and were cultured by pour plate technique within 2 hours. 9-11

    Colony count of >105 organisms per ml was considered positive. 1,7,8,12 The antimicrobial sensitivity of organisms to 11 most commonly prescribed antibiotics were examined by the standard disk diffusion technique.

    Results

    From 195 patients enrolled into the study, 146 had their catheter in place for 72 hours. In 37 patients (25%) a change from negative to positive culture was detected in consecutive specimens. In almost all (n=143) of the patients only one organism was isolated. Nontheless, in the remaining three patients, two organisms were isolated.

    From the 40 different organisms isolated, the majority belonged to K. pneumoniae (60%), E. cloacae (25%), E. coli (7.5%), P. mirabilis (5%) and P. aeroginosa (2.5%) (Fig. 1).

    There was a total resistance of K. pneumoniae, E. cloacae, and P. mirabilis to ampicillin, chloramphenicol, carbenycillin, cephalotin, tetracyclin, and co-trimoxazole. These strains were completely sensitive to amikacin and nalidixic acid. Their resistance to nitrofurantoin and gentamicin was partial (16.6%, and 58%, respectively) (Fig. 2).

    E. coli had a different pattern, and the resistance was detected just to ampicillin, carbencillin and tetracyclin (Fig. 3).

    Discussion

    The incidence of catheter-associated UTI in gynecology ward had a large variance in different studies.

    Isolated strains in this study differ from those reported in other studies. E. coli was reported as the most common agent in some reports.1,7,12,13 In this study, however, it ranked the third (7.5%). The most common organism isolated in our study was being K. pneumoniae which is in concordance with a study performed in Thailand 14.

    According to current medical literature, P. aeruginosa must be the second most common organism,7 however, it was the least common in our study. Moreover, we could not detect any Gram positive organism.

    In the United States, 12 of 14 UTI epidemics were due to Proteus, Klebsiella, and Serratia (probably due to their high antibiotic resistance). In this study, Proteus and Kelebsiella were the most common isolates (65%).

    Regarding the antimicrobial resistance of these isolates, three categories could be identified; P. aeruginosa strain was sensitive to amikacin only. K. pneumoniae, E. cloacae, and P. mirabilis were sensitive to amikacin and nalidixic acid but were highly resistant to other antibiotics. And, E. coli strains were resistant only to ampicillin, tetracyclin and cephalotin. Drug resistance is generally a common and prevalent issue.

    In summary, there are three distinct difference between this study and other reports: 1) P. aeruginosa was rare in our center. 2) E. coli was less common than that expected, however, its sensitivity pattern was similar to out-patient cases. 3) in different reports Gram positive cocci do have a considerable role13,15,16 which was not true for our center.

    It could be stated that drug resistance in this study is following its worldwide pattern and perhaps some part of the resistance could be attributed to a routine antibiotic regimen administered in our center.

    As a conclusion, the organisms were most sensitive to amikacin and nalidixic acid and they seem to be the most effective antibiotics for nosocomial catheter-associated UTIs.

    References

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    12. Warren JW, Platt R, Thomas RJ, Rosner B, Kass EH. Antibiotic irrigation and catheter-associated urinary tract infection. New Engl J Med 1978; 299: 570-3.
    13. Pien FD, Landers JQ. Indwelling urinary catheter infections in small community hospital, Urol 1983; 22: 255-8.
    14. Tangtrakul S, Tachaiya S, Suthutvoravut S, Linasmita V. Post-cesarean section urinary tract infection: a comparison between intermittent and indwelling catheterization. J Med Assoc Thai 1994; 77(5): 244-8.
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