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Rising Resistance In Uropathogens With An Indication Of Nitrofurantoin Mic Creep
Azra S Hasan1, Richa Garg2, Sowmya Nasimuddin3
1Department of Microbiology, School of Medical Science and Research, Sharda University, UP, India.
Background:
The irrational use of antibiotics has led to the emergence of multi drug resistant pathogens. The phenomenon of MIC creeps occurs when organisms start showing raised MIC but within susceptible range giving an indication of the prevalence of rise in resistant pathogens in an area.
Methods:
A cross sectional study in a large tertiary care hospital in North India to observe the susceptibility pattern among uropathogens and the possibility of MIC creeps. The Antimicrobial Susceptibility Testing (AST) and Minimum Inhibitory Concentration (MIC) were conducted by Vitek Compact 2. The identification of Extended Spectrum Beta Lactamase (ESBL) producers and Carbapenem Resistant Enterobacteriaceae (CRE) among Escherichia coli were noted. The MIC 50 and MIC 90 for Nitrofurantoin, the most widely used antibiotic for lower UTI, was calculated to investigate the phenomenon of MIC creep.
Results:
In our study, a total of 2522 urine samples were analyzed: 1538 (61%) were positive with the commonest isolate being E. coli (n=736, 47.8%) followed by Klebsiella spp. (n=178, 11%). Less than 10% of resistance was observed for Fosfomycin, Amikacin, Nitrofurantoin, Imipenem, Meropenem and Colistin. ESBL producers and CRE E. coli were 528 (72% of 736) and 79 (11% of 736) respectively. Overall, 119/736 samples had an MIC ≥128. Amongst the ESBL producers, 96/528 had MIC ≥128 and amongst the CRE, 13/79 had MIC ≥128.
Discussion:
E. coli can be used to reflect the trends in development of resistance. In the current study, it was observed that E. coli showed a reduced susceptibility for Nitrofurantoin indicated by a creeping increase in MIC albeit within normal range.
Conclusions:
Trends in rising MIC should alert prescribers to use drugs such as Nitrofurantoin judiciously. Antimicrobial stewardship practices should be strongly implemented in hospitals to curb rising resistance and obtain better treatment outcomes for patients with infectious diseases.
Insights
Rising antibiotic resistance is a growing concern. This study observed increasing Minimum Inhibitory Concentration (MIC) values for Nitrofurantoin in E. coli, indicating a potential rise in resistance despite remaining within susceptible ranges.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Background:
- Irrational antibiotic use fuels multi-drug resistant pathogens.
- Minimum Inhibitory Concentration (MIC) creep, a rise in MIC within the susceptible range, signals increasing resistance.
- Urinary tract infections (UTIs) are common, with E. coli being a frequent causative agent.
Purpose of the Study:
- To investigate antimicrobial susceptibility patterns among uropathogens.
- To identify the phenomenon of MIC creep in a tertiary care hospital in North India.
- To assess trends in Nitrofurantoin resistance in E. coli.
Main Methods:
- A cross-sectional study analyzed 2522 urine samples.
- Antimicrobial Susceptibility Testing (AST) and MIC were performed using Vitek Compact 2.
- Prevalence of Extended Spectrum Beta Lactamase (ESBL) and Carbapenem Resistant Enterobacteriaceae (CRE) E. coli was determined.
- MIC 50 and MIC 90 for Nitrofurantoin were calculated.
Main Results:
- E. coli was the most common isolate (47.8%) from 1538 positive samples.
- Resistance to Fosfomycin, Amikacin, Nitrofurantoin, Imipenem, Meropenem, and Colistin was less than 10%.
- ESBL and CRE E. coli accounted for 72% and 11% of E. coli isolates, respectively.
- 119/736 E. coli isolates had an MIC ≥128 for Nitrofurantoin.
Conclusions:
- E. coli serves as a reliable indicator for monitoring antimicrobial resistance trends.
- A creeping increase in Nitrofurantoin MIC values for E. coli suggests reduced susceptibility.
- Judicious use of Nitrofurantoin and robust antimicrobial stewardship are crucial to combat rising resistance.
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