Merit of mobilization technique in transfer of non-autotransferable R-plasmids.

A total of 200 urinary isolates of Esch.coli received at National Salmonella and Escherichia Centre, Central Research Institute, Kasauli during the years 1995 to 1997 were studied for transferable drug resistance. Out of 188 strains, 134 strains showing resistance to either Nalidixic acid or Rifampicin were subjected to autotransferable resistance studies. Of these 134 strains 131 showed either partial or enbloc transfer of R-factor. Mobilization experiment successfully transferred resistance marker in 14 of the 68 isolates in which resistance to one or more drugs could not be transferred during conjugation experiment.

Prevalance and resistance pattern of Salmonella serotypes in India.

During the period 1990-91, 3222 Salmonella strains were identified at the National Salmonella and Escherichia Centre (NSEC) at Central Research Institute, Kasauli. Of these, 2894 were from humans, 226 from poultry, 84 from animals and remaining 18 from reptiles, birds and other sources. These strains belonged to 53 different serotypes. These include 4 serotypes reported for the first time in India, namely S. kedogou, S. VP. bornheim, S. kisarawe and S. madras. Drug resistance studies revealed that 573 strains were sensitive to all the antibiotics commonly used, 1351 single drug resistant, 594 resistant to two drugs and 704 were multidrug resistant. One strain from human stool was resistant to all the antibiotics used. Prevalence of various Salmonella serotypes and their response to various drugs is discussed.