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Published on: March 3, 2023

Multiple antibiotic resistance among gram negative bacteria isolated from milk in Karachi

A Ahmed1, N Jameel, F A Ansari

  • 1Department of Microbiology, University of Karachi, Karachi-75270, Pakistan.

Pakistan Journal of Pharmaceutical Sciences
|January 18, 2006
PubMed

Insights

Antibiotic resistance in Gram-negative bacteria from Karachi milk is significant, with 46% showing resistance. Eight of these bacteria carried non-transferable R plasmids, indicating a potential public health concern.

Area of Science:

  • Microbiology
  • Bacteriology
  • Molecular Biology

Background:

  • Antibiotic resistance in food-producing animals is a growing global health concern.
  • Milk can be a vehicle for the transmission of resistant bacteria to humans.
  • Gram-negative bacteria are common milk contaminants and potential reservoirs of resistance genes.

Purpose of the Study:

  • To investigate the prevalence of antibiotic resistance in Gram-negative bacteria isolated from milk in Karachi.
  • To determine the presence and types of R plasmids in resistant bacterial isolates.

Main Methods:

  • Isolation and identification of Gram-negative bacteria from milk samples.
  • Antibiotic susceptibility testing against eleven common antibiotics at 100 µg/ml.
  • Detection of R plasmids using conjugation, spontaneous segregation, and curing with acridine orange and ethidium bromide.

Main Results:

  • 46% of 100 Gram-negative bacteria isolates exhibited resistance to at least one antibiotic at 100 µg/ml.
  • Eight resistant isolates were found to harbor non-transferable R plasmids.
  • Multiple resistance patterns were observed among the resistant isolates.

Conclusions:

  • A significant proportion of Gram-negative bacteria in Karachi milk possess antibiotic resistance.
  • Non-transferable R plasmids are present in some resistant milk bacteria, contributing to the resistance.
  • Further research is needed to understand the full scope of antibiotic resistance in the food chain.

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