Homologous Resistant Groups (HRGs) in Multidrug Resistant Staphylococcus aureus Isolated from Retail Foods in Vadapalani, Chennai
M Manoharan, S Jayaraman, S Illanchezian, J Jayasekar
antibiotic resistance, homologous resistance groups hrgs, mar, mrsa, staphylococcus aureus
M Manoharan, S Jayaraman, S Illanchezian, J Jayasekar. Homologous Resistant Groups (HRGs) in Multidrug Resistant Staphylococcus aureus Isolated from Retail Foods in Vadapalani, Chennai. The Internet Journal of Microbiology. 2008 Volume 7 Number 1.
The present study investigated the prevalence of multiple antibiotic resistant
Food borne diseases are of major concern worldwide. To date, around 250 different food-borne diseases have been described and bacteria are the causative agents for two-thirds of the food-borne disease outbreaks. Among the predominant bacteria involved in these diseases,
Materials and methods
A total of 40 different food samples collected from retail shops and markets in Vadapalani, Chennai were subjected to
Antibiotic resistance test was carried out for all the strains by the disc diffusion method (Bauer
Multiple Antibiotic Resistance (MAR) indexing of the isolates
The MAR index of a single isolate is defined as a / b, where 'a' represents the number of antibiotics to which the isolate was resistant and 'b' represents the total number of antibiotics to which the isolate was subjected (Krumperman, 1985).
Typing of S. aureus isolates
Where NAB is number of similar antibiotics resistant to both strains; NA is the total number of antibiotics resistant to strain 1; and NB is the total number of antibiotics resistant to strain 2.
Cluster analysis was performed using the unweighted pair-group method with average linkages (UPGMA, Sneath and Sokal, 1973). The isolates showing similar antibiotic resistance pattern and S.I. value of 1 were grouped as homologous resistance group (HRG).
About 80% (32 / 40) of the food samples collected from retail shops and markets in Vadapalani, Chennai were positive for contamination with
About 93.75% of the
Antibiotic resistance typing
This is the first report on the prevalence of multiple antibiotic resistant
a seafood samples collected from Vadapalani; b milk samples collected from Vadapalani; c fruit samples collected from Vadapalani; d vegetables collected from Vadapalani; e juice samples collected from Vadapalani
was observed in the food samples taken for analysis. These results are high compared to that documented by other researchers (Genigeorgis 1989; Sokari 1991; Wieneke
In the present study, the wide spread contamination of MRSA in food samples was observed. All the isolates were sensitive to gentamicin and norfloxacin. This is because of the less (or) nil exposure of food samples to these antibiotics, whereas, some clinical isolates have shown resistance to gentamicin and norfloxacin (Daxboeck
The incidence of
A novel approach of typing
We thank the management of Life Teck Research Centre, Chennai for providing us the facilities and requisite support for completion of this work. We thank all our co-workers for providing us constant support throughout this work and also in the successful preparation of this manuscript.