The spectrum of nasal colonization: frequency and resistant patterns in diabetes versus non-diabetes population

The nasal cavity serves as a primary contact site and is a common location for colonization by symbiotic, opportunistic, and potentially pathogenic bacteria. Diabetic patients are more susceptible to colonization by opportunistic microorganisms due to impaired immune function, altered normal flora, and increased exposure to healthcare. This study aimed to investigate the nasal colonization of Gram-positive (Staphylococcus aureus) and Gram-negative (Enterobacteriaceae) bacteria in diabetic and non-diabetic individuals, assessing phenotypic traits including antibiotic resistance and biofilm production, as well as investigating the presence of resistant genes.

In this cross-sectional study, nasal swabs were collected from 150 diabetic and 150 non-diabetic individuals. Isolates were identified and evaluated phenotypically (Antibiotic resistance using the disk diffusion method and biofilm formation by the microtiter plate method) and genotypically (resistance genes including mecA, bla_CTX, bla_SHV, and bla_TEM) by PCR.

The rate of S. aureus colonization was higher in diabetics (18.7%) than in non-diabetics (12.7%) and MRSA colonization was significantly higher in diabetics (8% vs. 1.3%). High antibiotic resistance was not observed except for tetracycline (nearly 50%) in S. aureus isolates from both groups. There was no statistically significant difference in the occurrence of MDR S. aureus between the diabetic (32.1%) and non-diabetic (31.6%) groups. Enterobacteriaceae colonization was 3.3% in diabetics and 7.3% in non-diabetics. Although none were phenotypically ESBL-positive, bla_CTX, bla_TEM, and bla_SHV genes were present in about 40% of the isolates.

Nasal MRSA colonization was more common among diabetic patients than non-diabetics. The findings of this study highlight the need for ongoing monitoring of nasal colonization of MRSA in different populations and settings, which may lead to the development of effective preventive and therapeutic strategies to control infections caused by nasal colonization.