|Year : 2001 | Volume
| Issue : 1 | Page : 62-64
Cross-resistance between trimethoprim-sulfamethoxazole and other common antibiotics among urinary isolates of escherichia coli - an in-vitro retrospective analysis
BV Navaneeth, N Suganthi, MR Sandhya Belwadi
Department of Microbiology, M.S. Rainaiah Medical College (MSRMC) and Teaching Hospital, Bangalore, India
B V Navaneeth
Department of Microbiology, M.S. Ramaiah Medical College and Hospital, Gokula Extension, Bangalore - 560 054
Source of Support: None, Conflict of Interest: None
| Abstract|| |
472 non-repetitive urinary isolates of E.coli (349 resistant and 123 sensitive to trimethoprim-sulfametho.xazole) from patients with culture documented UTI were isolated between January 1998-December 1999. Data on antibiograrn of these isolates were fed into WHONET computer program. The relationship between trimethoprim-sulfamethoxazole (T-S) resistance and resistance to other common antimicrobials among E. coli was statistically analyzed by comparing T-S resistant with T-S sensitive isolates against other antimicrobial agents. T-S resistant E.coli were more likely to be resistant to ampicillin, augmentin, cejazolin and norfloxacin (P<0.001) but not for gentanicin and nitrofurantoin (P>0.05). T-S resistance among urinary isolates of E.coli may be a risk fatctor that would likely be associated with resistance to other antimicrobial agents used to treat UTI.
Keywords: Urinary Tract Infection; Trimethoprim-Sulfamethoxazole; Antimicrobial Cross Resistance; E.coli.
|How to cite this article:|
Navaneeth B V, Suganthi N, Sandhya Belwadi M R. Cross-resistance between trimethoprim-sulfamethoxazole and other common antibiotics among urinary isolates of escherichia coli - an in-vitro retrospective analysis. Indian J Urol 2001;18:62-4
|How to cite this URL:|
Navaneeth B V, Suganthi N, Sandhya Belwadi M R. Cross-resistance between trimethoprim-sulfamethoxazole and other common antibiotics among urinary isolates of escherichia coli - an in-vitro retrospective analysis. Indian J Urol [serial online] 2001 [cited 2021 Aug 4];18:62-4. Available from: https://www.indianjurol.com/text.asp?2001/18/1/62/37420
| Introduction|| |
Co-trimoxazole, a combination of trimethoprimsulfamethoxazole (T-S) is used as one of the representative first line agents in urinary tract infections (UTIs). There is increasing resistance to T-S among isolates of E.coli in developing countries. Its resistance is likely to be associated with resistance to other pharmacologically unrelated agents commonly used to treat ambulatory infections, including ampicillin, orally administered first generation cephalosporins and norfloxacin. Hence a preliminary correlation was attempted statistically to know the association between T-S resistance and resistance to other common antibiotics among E.coli.
| Patients and Methods|| |
The study was performed in the department of Microbiology, M.S. Ramaiah Medical College and Teaching Hospital, Bangalore. Between January 1998-December 1999. 472 non-repetitive isolates of E.coli were isolated from urine samples. Antibiotic susceptibility pattern of these E.coli isolates (349 resistant and 123 sensitive to T-S) was fed into WHONET computer programme. Bauer-Kirby disc diffusion' was the method followed for the antibiotic susceptibility test. Ampicillin (l0µ gms), amoxy-clavulanic acid (30 µ gms), cefazolin (30µ gms), gentamicin (10p -ms), nitrofurantoin (300µ gms), and norfloxacin (10 µ gms) are the common antibiotic discs (HiMedia) used apart from T-S (25µ gms). Comparison of resistance pattern between T-S resistant and T-S sensitive E.Coli to other antibiotics were analyzed. Statistical evaluation of resistance values obtained from both T-S resistant and T-S sensitive group was performed by Chi-square test.
| Results|| |
Out of 472 urinary isolates of E.coli, 349 were resistant (73.9%) and 123 were sensitive (26%) to T-S. Resistance pattern of T-S resistant and T-S sensitive urinary isolates of E.coli in relation to other antimicrobial agents are shown in the table. The analysis indicates that isolates resistant to T-S were more likely to be resistant to ampicillin, augmentin, cefazolin and norfloxacin (P<0.001). However no significant association was noted between T-S resistance and resistance to gentamicin and nitrofurantoin (P>0.05).
| Discussion|| |
The present study correlates well with the study from Canada showing similar correlation between T-S resistant and other antibiotics especially ampicillin. Of particular concern in T-S is the resistance often carried on transferable R factors that confer resistance to multiple antimicrobials, emphasizing the way one agent may effect resistance to many others. Study from Houston Texas shows 96% of 165 trimethoprim (TMP) resitant E.coli were resistant to four drugs and 25% were resistant to seven; TMP resistance was transferable in 40 of 100 strains tested. The real hazard of such multiple resistance strains is that if the genes for TMP resistance coexist in the same bacterium with genes encoding other resistances, the use of any one of these agents may lead to selection and maintenance of resistance to all the other agents as well. It is not clear from where antimicrobial resistance genes have originated and how multiple determinants for anti microbial resistance accumulate on a given R plasmid. Several studies have shown that the process by means of transposition may play a role in the building of R plasmids especially in hospital environments., Pathetically no agents are available to prevent or interrupt the transposition process selectively and efficiently. Although nalidixic acid may prevent transfer of plasmids, it is yet to be used for this purpose in clinical situations.
In conclusion the present study highlights T-S resistance among E.coli might probably act as a risk factor that would likely to be associated with resistance to other agents which needs further molecular biological investigations.
| Acknowledgement|| |
We are grateful to AstraZeneca Research Foundation India, Bangalore for computerized data compilation and Narsimhamurthy N.S., department of community medicine, MSRMC for assisting in statistical evaluation.
| References|| |
|1.||Murray BE. Alvarado T, Kim KH et al. Increasing resistance to trimethoprim-sulfamethoxazole among isolates of Escherichia coli in developing countries. J Infect Dis 1985: 152: 1107-1113. |
|2.||Allen UD. MacDonald N, Fuite L. Chan F. Stephens D. Risk factors for resistance to "first-line" antimicrobials among urinary tract isolates of Escherichia coli in children. CMAJ 1999: 160: 1436-1440. |
|3.||Stelling JM. O'Brien TF. Surveillance of antimicrobial resistance: the WHONET program. Clin Infect Dis 1997: 24 (Suppl. 1): 157-168. |
|4.||Bauer AW. Kirby WMM. Sherris JC. Turck M. Antibiotic susceptibility testing by a standardized single disk method. J Clin Pathol 1996: 105: 493-496. |
|5.||Daniel WW. Biostatistics: A foundation for analysis in the Health Science. 6th ed. John Wiley and Sons. Inc. New York 1995. |
|6.||Weinstein RA. Multiply drug resistant pathogens: Epidemiology and control. In: Bennett JV, Brachman PS (ed.). Hospital Infections. 3rd ed. Little Brown and Company 1992: 265-268. |
|7.||Murray BE. Rensimer ER. DuPont HL. Emergence of high-level trimethoprim resistance in fecal Escherichia coli during oral administration of trimethoprim or trimethoprim-sull'amethoxazole. N Engl J Med 1982: 306: 130-135. |
|8.||Datta N. Hughes VM, Nugents ME. Richardo H. Plasmids and transposons and their stability and mutability in bacteria isolated during an outbreak of hospital infection. Plasmid 1979; 2: 182. |
|9.||Rubens CE. Farrar WE. McGee ZA. Schaffner W. Evolution of plasmid mediated resistance to multiple antomicrobial agents during prolonged epidemic of nosocominal infections: A molecular biological investigation. J Infect Dis 1981: 143: 170. |
|10.||Gills, Iyer VN. Nalidixic acid inhibits the conjugal transfer of conjugative N incompatibility group plasmids. Can J Microbiol 1982: 28: 256. |
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