# Co-isolation of Achromobacter species and Vibrio parahaemolyticus from a case of chronic suppurative otitis media in a sea swimmer: a case report

## TL;DR

A rare case of chronic ear infection in a sea swimmer shows the co-occurrence of two uncommon bacteria, suggesting a possible marine source and need for targeted treatment.

## Contribution

Reports the first known co-isolation of Achromobacter species and Vibrio parahaemolyticus in chronic suppurative otitis media.

## Key findings

- Achromobacter species and Vibrio parahaemolyticus were isolated from a sea swimmer with chronic ear infection.
- Achromobacter showed multidrug resistance, while Vibrio was susceptible to specific antibiotics.
- Targeted therapy improved the patient's condition, highlighting the importance of culture-based diagnosis.

## Abstract

Achromobacter species and Vibrio parahaemolyticus are environmental gram-negative bacteria that are rarely implicated in chronic suppurative otitis media (CSOM). Achromobacter species are emerging opportunistic pathogens, primarily associated with respiratory infections in immunocompromised individuals, while Vibrio parahaemolyticus is typically associated with seafood-related gastroenteritis. This case highlights the co-isolation of Achromobacter species and Vibrio parahaemolyticus from a patient with CSOM who frequently engaged in sea swimming, suggesting their potential role in CSOM pathogenesis and a possible environmental source of infection.

A 15-year-old male, a sea swimmer, presented with persistent otorrhea and hearing impairment despite multiple courses of antibiotics. Otoscopic examination revealed tympanic membrane perforation with purulent discharge. Microbiological culture of the ear discharge isolated Achromobacter species and Vibrio parahaemolyticus, confirmed by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF MS). Achromobacter species exhibited multidrug resistance, with susceptibility only to carbapenems, whereas Vibrio parahaemolyticus was susceptible to fluoroquinolones and tetracyclines. Targeted antimicrobial therapy led to clinical improvement.

This case underscores the need to consider Achromobacter species and Vibrio parahaemolyticus as potential pathogens in non-resolving CSOM cases, especially in individuals exposed to marine environments. Their multidrug-resistance patterns highlight the importance of culture-based diagnosis and susceptibility testing for effective management. Further studies are needed to explore the epidemiology and clinical significance of Achromobacter species and Vibrio parahaemolyticus in ear infections.