# Nasal carriage rate and multiple antimicrobial resistance indices of Staphylococcus aureus among healthcare students at the Ahmadu Bello University, Nigeria

## TL;DR

This study found high rates of drug-resistant Staphylococcus aureus in healthcare students in Nigeria, highlighting potential public health risks.

## Contribution

First study in Africa to assess multiple antimicrobial resistance indices of nasal S. aureus in healthcare students and categorize subgroup variations.

## Key findings

- 31.5% of students carried S. aureus, with 23.5% being MRSA.
- Medical and pharmacy students had significantly higher MDR-S. aureus carriage.
- Tetracycline and ciprofloxacin showed the highest resistance among isolates.

## Abstract

Healthcare students could harbour multidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA). There is a need to understand the extent and factors associated with nasal carriage of these strains.

This study determined the frequency and risk of nasal S. aureus, and multiple antimicrobial resistance indices among students at Ahmadu Bello University, Zaria, Nigeria.

This comparative cross-sectional study collected nasal samples from 02 January 2024 to 31 July 2024 from healthcare students at Ahmadu Bello University, Nigeria, which were processed for S. aureus identification. Antimicrobial resistance phenotype was determined by the disk diffusion method. Structured questionnaires were used to collect participants’ sociodemographic and risk factor data.

A total of 251 students participated, including 126 (50.2%) men and 125 (49.8%) women (aged 17–44 years). The nasal carriage of S. aureus was 31.5% (79/251) and MRSA was 23.5% (59/251). Clinical-phase students had a higher frequency of nasal MRSA (25%) than preclinical-phase students (22.1%). Staphylococcus aureus resistance against non-beta-lactams was highest for tetracycline (49.4%) and ciprofloxacin (29.1%), with 39.2% (31/79) showing MDR. Medical and pharmacy students had statistically significant higher nasal carriage of MDR-S. aureus (p < 0.05). Students residing in households of 5–8 individuals had the highest nasal MDR-S. aureus carriage (p = 0.0044). Staphylococcus aureus isolates with multiple antimicrobial resistance indices of 0.2 (29.1%) and 0.3 (24%) were the most predominant.

High levels of nasal MRSA and MDR-S. aureus were obtained from this study. The predominance of strains with high antimicrobial resistance indicates sources with high antibiotic use.

To our knowledge, this is the first epidemiological study on the multiple antimicrobial resistance indices of nasal S. aureus in healthcare students in Africa. Moreover, this is the first report to categorises subgroup variation of nasal MDR-S. aureus carriage by the six major groups of healthcare students.