Class 1 and 2 integrons and antibiotic resistance profile in Salmonella spp. from San Cristobal River, Laguna, Philippines

ABSTRACT

Infection with multidrug resistant bacteria is a significant public health concern. Bacteria culture of water samples (n=120) collected in San Cristobal River, Philippines, showed that half (n=60) were positive for Salmonella spp. Screening of all isolates (n=179) for susceptibility to antibiotics showed that most (76.4%; n=113) were positive for class 1 integrons, of which one isolate was also positive for the class 2 integron. The presence of class 1 integrons was associated with resistance to antibiotics (p<0.05). Sequencing of class 1 integron variable regions (VRs) differeciated 11 gene cassettes: dfrA1 or dfrA17; aadA1 or aadA2; blaCTX-M-2 or bla-OXA-1; SmdAB; CmlA1 and aaC 3-Id. However, sequencing of class 2 integron VR differenciated estX, sat2, and aadA1. These results provide insights into evolutionary changes within bacterial multidrug resistant cassettes, more accurately to estimate heath risk associated with the river water.            

KEYWORDS:

• Antibiotics
• Salmonella spp.
• integrons
• multidrug resistance
• San Cristobal River

Acknowledgements

The authors acknowledge the intellectual and financial contribution (funding reservation no: 3240266445) from the Organization for Women in Science for the Developing World (OWSD) and the Swedish International Development Cooperation Agency (SIDA). They also thank the Laboratory of Microbial Genetics, UPLB, for the use of their facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Organization for Women in Science for the Developing World [3240266445].