# Culture-Based Wastewater Surveillance for the Detection and Monitoring of Antimicrobial Resistance in Staphylococcal Species

## TL;DR

This study used wastewater to track antibiotic-resistant staphylococcal bacteria in Dubai, finding diverse resistant strains and highlighting wastewater as a tool for early detection of antimicrobial resistance.

## Contribution

The study provides new insights into the diversity and antibiotic resistance patterns of Staphylococcus species in wastewater from the Arabian Gulf region.

## Key findings

- Wastewater in Dubai contained diverse Staphylococcus species, including multidrug-resistant strains.
- Resistance was highest to benzylpenicillin and fusidic acid, but all isolates remained susceptible to glycopeptides, tigecycline, and linezolid.
- Wastewater surveillance revealed potential for tracking antimicrobial resistance across human, animal, and environmental interfaces.

## Abstract

Antimicrobial resistance, when bacteria change in ways that make antibiotics no longer effective, has become one of the most serious global healthcare challenges of our time. This study examined bacteria found in wastewater in Dubai to better understand how resistant bacteria spread across the community, hospitals and the environment. The focus was on a group of bacteria called Staphylococcus, some of which can cause a wide range of infections in humans and animals, from mild skin infections to serious bloodstream diseases. Over an eight-month period, wastewater samples were collected from community locations, hospitals, and wastewater treatment plants. The bacteria were isolated and tested in the laboratory to determine which antibiotics could stop them and which ones couldn’t. We found a diverse range of Staphylococcus species, including several that showed resistance to multiple commonly used antibiotics. Reassuringly, some strong antibiotics remained effective against these bacteria. Overall, our findings suggest that wastewater can act as an important early warning system for detecting and tracking antimicrobial resistance before it becomes a larger public health problem. Monitoring wastewater offers valuable insights into how resistance spreads and can help guide actions to protect humans, animals and the environment.

Wastewater-based surveillance (WBS) is valuable for monitoring antimicrobial resistance (AMR). Staphylococci are key targets, as wastewater can facilitate gene transfer and resistance emergence. Data on WBS for population-level AMR in the Arabian-Gulf remain limited. This study assessed Staphylococcus diversity and resistance in Dubai wastewater. Samples were collected over eight months from nine community sites, two hospital nodes, and two wastewater treatment plants (WWTPs) and were analysed by culture-based method. Ninety-six Staphylococcus isolates were recovered from community, hospital, and WWTP influent, with no growth in effluent. Most isolates (n/N = 88/96) were coagulase-negative Staphylococcus (CoNS), spanning 15 species, dominated by S. saprophyticus, S. cohnii and S. sciuri. The only coagulase-positive Staphylococcus was S. aureus (n = 8) and the only species detected across all wastewater sources. Resistance was highest to benzylpenicillin (88%) and fusidic acid (82%), whereas all isolates remained susceptible to glycopeptides, tigecycline, and linezolid. Fusidic acid resistance was higher in community-wastewater isolates, whereas β-lactam resistance predominated in hospital-wastewater isolates. Sixty percent of CoNS were multidrug-resistant; methicillin resistance occurred in 37.5% of CoNS and 50% of S. aureus. Wastewater is a reservoir of diverse multidrug-resistant staphylococci, underscoring One Health relevance reflecting the potential for circulation between humans, animals, and the shared environment. WBS can support population-level AMR monitoring to inform public health and veterinary interventions.