Full Length Research Paper

Plasmid-borne antibiotics resistant markers of Serratia marcescens:  an increased prevalence in HIV/AIDS patients

Yah S. C.¹*, Eghafona N. O.² and Forbi J. C. ³

¹Department of Biological Sciences, College of Science and Technology, Covenant University, Km 10 Idiroko Road, PMB 1023 Ota, Ogun State, Nigeria.

²Department of Microbiology, Faculty of Life Sciences, University of Benin, Benin City, Edo State, Nigeria.

³Department of Virology, Innovative Biotech, Keffi/Abuja, Nigeria.

*Corresponding author. E-mail: yahclar@yahoo.com. Phone: +2348053336108 or +2348063418265.

Accepted 20 November 2007

This study  was  carried  out  to  evaluate  the  resistant  pattern  of  multi-drug resistant strains of Serratia marcescens associated with HIV/AIDS infected individuals in Nigeria. A total 1709 samples (1323 urine and 406 diarrhea stool) were collected from individuals living with HIV/AIDS over a three year period and screened for plasmid-mediated S. marcescens susceptibility profile to antibiotics. These individuals had been confirmed HIV positive and their CD4 cells enumerated using the Partec cyflow (Partec GmbH, Germany). The CD4 values ranged between 14 and 812 cells/µl of blood. During this period, ninety-four (94) S. marcescens  strains  were isolated  of  which  38(40.4%)  were  from  urine  samples  while  56(59.6%) were from  diarrhea stool samples. The resistance patterns of the isolates varied (p<0.05) within all the antibiotics tested. The resistant genes were highly encoded on transferable plasmids with a varied frequency of 2 x 10^-2 to 6 x 10^-3 per donor cell by conjugation. Eight out of nine of the samples (88.9%) had multiple plasmids with molecular weights range between 1.14 and 6.0 kb. Curing experiment results showed that resistance genes were also chromosomally mediated. This indicates that there is a high antibiotic resistant genes marker among S. marcescens strains in HIV/AIDS individuals in Nigeria.

Key words:  Plasmids Borne- Serratia marcescens-HIV/AIDS