Contamination by Antibiotic-Resistant Bacteria in Selected Environments in Thailand

This study determined the presence of important antibiotic-resistant bacteria in selected environments in Thailand, including wastewater samples from 60 hospitals; washed fluid, leachate, flies, cockroaches, and rats collected from five open markets; washed fluid from garbage trucks; and stabilized leachate from a landfill facility. At least one type of antibiotic-resistant bacteria was isolated from all samples of influent fluid before treatment in hospitals, from wastewater treatment tank content in hospitals, and from 15% of effluent fluid samples after treatment with chlorine prior to draining it into a public water source. Antibiotic-resistant bacteria were recovered from 80% of washed market fluid samples, 60% of market leachate samples, all fly samples, 80% of cockroach samples, and all samples of intestinal content of rats collected from the open markets. Antibiotic-resistant bacteria were recovered from all samples from the landfill. Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and/or Klebsiella pneumoniae were the most common antibiotic-resistant bacteria recovered from all types of samples, followed by carbapenem-resistant E. coli and/or K. pneumoniae. Colistin-resistant Enterobacteriaceae, carbapenem-resistant Psuedomonas aeruginosa, carbapenem-resistant Acinetobacter baumannii, colistin-resistant Enterobacteriaceae, vancomycin-resistant Enterococci, and methicillin-resistant S. aureus were less common. These findings suggest extensive contamination by antibiotic-resistant bacteria in hospital and community environment in Thailand.