First detection of Vibrio vulnificus and other potentially pathogenic Vibrio species on different types of waste material in the Gulf of Gdańsk.

BACKGROUND

Vibrio bacteria, including pathogens like Vibrio vulnificus (V. vulnificus) and Vibrio cholerae (V. cholerae) (typical for tropical regions), are increasingly reported in the Baltic Sea, with rising infections linked to climate change. In our study, we examined the presence of Vibrio species on waste materials floating in the coastal zone.

MATERIAL AND

METHODS

Seventy-five waste items were collected. Samples were rinsed, homogenized, and cultured on CHROMagar Vibrio and thiosulfate-citrate-bile salts-sucrose (TCBS) agar. Vibrio isolates were tested for their tolerance to salinity and susceptibility to antibiotics.

RESULTS

Vibrio contamination was most common on medical waste (46.15%), followed by plastic film (16%), and both cigarette butts and other waste (14.28%). No Vibrio was detected on food packaging. Two of the 25 Vibrio isolates (V. cholerae/mimicus) showed resistance to cefotaxime (CTX), piperacillin-tazobactam (TZP), trimethoprim-sulfamethoxazole (SXT), and imipenem (IMP). Salinity strongly influenced growth: all isolates grew best at 2% salinity, with reduced growth at 5% and minimal growth at 10-15%.

CONCLUSIONS

The detection of V. vulnificus on medical waste such as band-aids raises concerns for individuals with open wounds, who should avoid seawater exposure during summer and replace wound dressings after swimming. Additionally, the presence of antibiotic-resistant V. cholerae/mimicus underscores the need for ongoing monitoring and further research into environmental reservoirs of pathogenic and drug-resistant Vibrio species.