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Phenotypic Detection and Antibiogram of β-lactamase-producing Proteus Species in a Tertiary Care Hospital, India
1Department of Microbiology, SMS Medical College, Jaipur, Rajasthan, India.
Background:
Proteus species cause a variety of community- and hospital-acquired illnesses. Synthesis of β-lactamases is the predominant mechanism for resistance to β-lactam antibiotics. Among the β-lactamases, extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases are the most common.
Aim:
The objective of this study was to determine the occurrence of ESBL and AmpC β-lactamases in Proteus species among various clinical isolates at a tertiary care hospital, India.
Materials And Methods:
This study was done to identify various species of Proteus from clinical samples (n = 3922). Antimicrobial susceptibility was performed by Kirby-Bauer disc diffusion method. ESBL production was detected by modified double-disc synergy test and indirect modified three-dimensional tests and AmpC β-lactamase production by AmpC disc test and modified Hodge test.
Results:
Proteus species were isolated in 5.4% (101/1876) specimens. Three Proteus species isolated were Proteus mirabilis 62.4% (63/101), Proteus vulgaris 29.7% (30/101), and Proteus penneri 7.9% (8/101). ESBL producers confirmed by both tests were of 88.1% (89/101). Only AmpC β-lactamase was produced by four isolates. Coproduction of ESBL and AmpC β-lactamase was observed in 58.4% (52/89) of isolates. Twelve isolates were non-β-lactamase producers. Multidrug resistance (MDR) was found in 95.1% (96/101) of isolates, 50.5% (51/101) were possibly extensively drug resistant and none were pan drug resistant. None of the isolates were resistant to piperacillin-tazobactam. P. penneri isolates exhibited high resistance to most of the antibiotics.
Conclusions:
A high prevalence of ESBL and AmpC β-lactamases was found that concurrently showed MDR. Phenotypic methods for the detection of β-lactamases are easy and simple and can be implemented in routine diagnostic laboratories along with susceptibility testing. These data will assist the clinicians in the management and control of infections.
Insights
A high prevalence of extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases was found in Proteus species, leading to multidrug resistance (MDR). Phenotypic detection methods are recommended for routine diagnostics.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Proteus species are significant causes of both community- and hospital-acquired infections.
- Beta-lactamase synthesis, particularly extended spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases, is a primary mechanism of resistance to beta-lactam antibiotics.
Purpose of the Study:
- To determine the prevalence of ESBL and AmpC beta-lactamases in Proteus species from clinical isolates.
- To assess antimicrobial resistance patterns in these isolates at a tertiary care hospital in India.
Main Methods:
- Identification of Proteus species from 3922 clinical samples.
- Antimicrobial susceptibility testing using Kirby-Bauer disc diffusion.
- Detection of ESBL and AmpC beta-lactamase production using phenotypic methods (modified double-disc synergy, indirect modified three-dimensional, AmpC disc, and modified Hodge tests).
Main Results:
- Proteus species were isolated in 5.4% of specimens, with Proteus mirabilis being the most common (62.4%).
- High rates of ESBL (88.1%) and AmpC beta-lactamase production were observed, with significant co-production (58.4%).
- Multidrug resistance (MDR) was prevalent in 95.1% of isolates; none were resistant to piperacillin-tazobactam. Proteus penneri showed high resistance.
Conclusions:
- A high prevalence of ESBL and AmpC beta-lactamases contributes to MDR in Proteus species.
- Simple phenotypic methods for beta-lactamase detection are suitable for routine diagnostic laboratories.
- Findings aid clinicians in managing and controlling Proteus-related infections.
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