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Published on: November 7, 2018
Quinolone resistant Salmonella species isolated from pediatric patients with diarrhea in central Iran
Elnaz Abbasi1, Ehsanollah Ghaznavi-Rad2,3,4
1Department of Microbiology and Immunology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Islamic Republic of Iran.
Background:
This study aimed to investigate the frequency and the antibiotic resistance patterns of Salmonella species that were isolated from infectious diarrhea samples taken from pediatric patients in central Iran.
Methods:
The study analyzed 230 stool specimens that were cultured on XLD, MacConkey agar and GN broth. Polymerase chain reaction (PCR) assay was used to identify the Salmonella genus. The antibiotic resistance profiles and the frequency of quinolone and integron genes were obtained.
Results:
Out of 230 samples of infectious diarrhea, 21 (9.1%) cases of Salmonella spp. were identified using culture methods. Another 28 (12.1%) samples had positive PCR results, with S. serovar Paratyphi B and C (9/21; 42.8%) and S. Typhi (3/21; 14.3%) being the most recognized. The highest antibiotic resistance rates were found for nalidixic acid (15/21; 71.4%), tetracycline (9/21; 42.8%). However, six (28.5%) of isolates were found resistant to cotrimoxazole, ampicillin and chloramphenicol. Among the plasmid-mediated quinolone resistance (PMQR) determinants, qnrS, qnrA, and qnrB were positive in (9/15; 60%), (6/15; 40%) and (3/15; 20%) of the isolates, respectively. Class 1 and 2 integrons were identified in 15 (71.4%) and 3 (14.3%) isolates, respectively.
Conclusion:
High rates of quinolone resistant and low frequency of MDR Salmonella spp. isolates were identified in central Iran, similar to findings in other parts of Asia. To prevent the spread of these resistant strains, the antimicrobial resistance of Salmonella spp. isolates should be under constant surveillance, and empiric antibiotic therapy should be adapted appropriately.
Insights
Antibiotic resistance in Salmonella species is a growing concern in pediatric infectious diarrhea cases in central Iran. This study highlights high quinolone resistance and the need for ongoing surveillance and adapted antibiotic therapies.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Biology
Background:
- Investigates the prevalence and antibiotic resistance patterns of Salmonella species in pediatric infectious diarrhea in central Iran.
- Addresses the increasing global challenge of antimicrobial resistance in bacterial pathogens.
Purpose of the Study:
- To determine the frequency of Salmonella species in pediatric stool samples.
- To analyze the antibiotic resistance profiles, including quinolone and integron genes, of isolated Salmonella strains.
Main Methods:
- Cultured 230 stool specimens using XLD, MacConkey agar, and GN broth.
- Employed Polymerase Chain Reaction (PCR) for Salmonella genus identification.
- Determined antibiotic resistance patterns and screened for quinolone resistance (PMQR) and integron genes.
Main Results:
- Identified Salmonella species in 9.1% (21/230) of samples by culture and 12.1% (28/230) by PCR.
- S. serovar Paratyphi B and C were most common (42.8%), followed by S. Typhi (14.3%).
- High resistance rates observed for nalidixic acid (71.4%) and tetracycline (42.8%); significant resistance to cotrimoxazole, ampicillin, and chloramphenicol (28.5%).
- Detected plasmid-mediated quinolone resistance (PMQR) genes (qnrS, qnrA, qnrB) and class 1 and 2 integrons in a substantial proportion of isolates.
Conclusions:
- Central Iran exhibits high rates of quinolone-resistant Salmonella and a low frequency of multidrug-resistant (MDR) Salmonella isolates.
- Findings align with trends observed in other Asian regions.
- Continuous surveillance of Salmonella antimicrobial resistance and adaptation of empirical antibiotic therapy are crucial to curb the spread of resistant strains.
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