Heterogeneous Vancomycin Intermediate Staphylococcus aureus Infections in Diabetic and Non-Diabetic Patients - A
Sreejisha M1, Shalini Shenoy Mulki1, Suchitra Shenoy1
1Department of Microbiology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 575001, India.
Purpose:
To study the infections caused by methicillin resistant Staphylococcus aureus (MRSA) with emphasis on heterogeneous vancomycin intermediate S. aureus (hVISA) in diabetic and non-diabetic patients and their comparison.
Patients And Methods:
S. aureus strains isolated from diabetic and non-diabetic patients admitted in four tertiary care hospitals in Coastal Karnataka, South India, were tested for methicillin resistance and included in the present study. Demographic and clinical data of the patients were collected using structured proforma. Antimicrobial susceptibility testing was done using the Kirby-Bauer disc diffusion method, and MLSB phenotypes were identified using the D-test. The minimum inhibitory concentration (MIC) of vancomycin was determined using agar dilution. MRSA isolates were tested for hVISA using vancomycin screen agar and population analysis profile - area under the curve (PAP-AUC) test. Statistical analysis of the results was done using the chi-square test. SPSS version 29.0 was used for this purpose.
Results:
Out of 665 strains of S. aureus isolated, 220 (33.1%) were MRSA. Of these 220 MRSA strains, 122 (55.5%) and 98 (44.5%) were isolated from diabetic and non-diabetic patients, respectively. There was no significant difference in the antimicrobial resistance patterns of MRSA strains isolated from diabetic and non-diabetic patients. Foot infections and osteomyelitis caused by MRSA were significantly more among diabetic patients. Out of 220 strains of MRSA, 14 (6.4%) were hVISA. The rates of hVISA among MRSA isolated from diabetic and non-diabetic were 9.0% and 3.1%, respectively. This difference was statistically not significant.
Conclusion:
The rate of hVISA among all MRSA isolates was 6.4%. The risk of hVISA infection was three times more in diabetic patients. The results emphasize the importance of the detection of hVISA among MRSA isolates especially from diabetic patients.
Insights
Diabetic patients face a higher risk of heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) infections, a significant finding for MRSA infection management. Early detection of hVISA in MRSA isolates is crucial, especially in diabetic populations.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Clinical Research
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global health threat.
- Vancomycin is a critical antibiotic for treating MRSA infections, but resistance is emerging.
- Heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) presents a challenge due to reduced susceptibility to vancomycin.
Purpose of the Study:
- To investigate MRSA and hVISA infections in diabetic and non-diabetic patients.
- To compare the prevalence and characteristics of these infections between the two groups.
- To highlight the clinical implications of hVISA in specific patient populations.
Main Methods:
- MRSA strains were isolated from diabetic and non-diabetic patients in South India.
- Antimicrobial susceptibility, vancomycin MIC, and hVISA screening (vancomycin screen agar, PAP-AUC) were performed.
- Demographic and clinical data were collected, and statistical analysis (chi-square test) was conducted.
Main Results:
- MRSA was isolated from 33.1% of S. aureus strains, with a higher proportion from diabetic patients (55.5%).
- Diabetic patients had significantly more MRSA-related foot infections and osteomyelitis.
- The overall hVISA rate was 6.4%, with a higher prevalence in diabetic patients (9.0%) compared to non-diabetic patients (3.1%), though not statistically significant.
Conclusions:
- The study identified a higher prevalence of hVISA among MRSA isolates from diabetic patients.
- Diabetic patients exhibited a threefold increased risk of hVISA infection.
- Emphasizes the critical need for hVISA detection in MRSA isolates, particularly in diabetic patients, to guide effective treatment strategies.
Related Concept Videos
01:20Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
01:26Urine Studies II: Urine Culture and Sensitivity Test