Antimicrobial Susceptibility of Indicator Bacteria Isolated from Chickens in Southeast Asian Countries (Vietnam, Indonesia and Thailand)

Abstract

To determine the prevalence of indicator bacteria resistant to antimicrobials among poultry in three Southeast Asian countries (Vietnam, Indonesia and Thailand), we examined the antimicrobial susceptibilities of commensal bacteria isolated from chickens. In total, 125, 117 and 180 isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium, respectively, were used to test for antimicrobial susceptibility. Bacterial resistance to antimicrobial treatment was most frequently observed with oxytetracycline with a prevalence of 73.6% (E. coli), 69.2% (E. faecalis) and 92.2% (E. faecium). Resistance to fluoroquinolones, which are critically important medicines, was also frequently observed in E. coli (48.8%), E. faecalis (17.9%) and E. faecium (82.8%). The prevalence of indicator bacteria resistant to most of the antimicrobials tested in these countries was higher than those for developed countries. The factors underlying antimicrobial resistance may include inappropriate and/or excessive use of antimicrobials. These results highlight the need for monitoring the emergence and prevalence of antimicrobial resistance in developing countries.

Antibiotic resistance profile of Enterococcus faecium andEnterococcus faecalis isolated from broiler cloacal samples

“…However, in the PCR analyses, none of these enterococci was found to have vancomycin resistance genes. Similarly, Usui et al (14) in their study in which they found low susceptibility to vancomycin (8 mg/L) in 4 isolates could not detect vanA and vanB resistance genes in these isolates. Therefore, it is evident that phenotypic tests alone are not sufficient to determine vancomycin resistance and that vancomycin resistance genes should also be identified.…”

Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry

“…Thus, high resistance to enrofloxacin can be associated with the administration of this drug at a therapeutic level for short periods of time or for preventive use in growing broilers. Resistance to fluoroquinolones was frequently observed in E. faecium (82.8%) and E. faecalis (17.9%) in countries of Southeast Asia (Usui et al, 2014). According to Maasjost et al (2015), fewer isolates, numbering 7 (5%) of E. faecalis and 10 (56%) of E. faecium from the internal organs of poultry, demonstrated resistance to ciprofloxacin.…”

Public Health Risks of Multiple-Drug-Resistant Enterococcus spp. in Southeast Asia

“…The large importers of livestock, mainly cattle and pigs, are Singapore, Malaysia, and Indonesia (24). Studies carried out in Malaysia, Thailand, Vietnam, Indonesia, and other Southeast Asian countries reported MDR enterococci isolated from livestock and animal-related products (23,25). Many Southeast Asian nations, such as Malaysia, Myanmar, Indonesia, Thailand, and Vietnam, have flourishing poultry and livestock industries and are also major exporters around the Asian region (26).…”

“…Although there is a large amount of data about the emergence of antimicrobial-resistant enterococci in Southeast Asian countries, most of this information is fragmented since it has been published in different papers in different countries over several decades (41)(42)(43)(44). However, several studies show the extent of unregulated and inappropriate use of antimicrobials in food animals in developing Southeast Asian countries such as Vietnam and Malaysia (23,25,45). Usui et al (25) obtained results that demonstrate the use of antimicrobials in chickens in Southeast Asian countries, especially Vietnam, to be higher than in developed countries (45).…”

“…However, several studies show the extent of unregulated and inappropriate use of antimicrobials in food animals in developing Southeast Asian countries such as Vietnam and Malaysia (23,25,45). Usui et al (25) obtained results that demonstrate the use of antimicrobials in chickens in Southeast Asian countries, especially Vietnam, to be higher than in developed countries (45). In Vietnam, colistin was reported as an antibiotic commonly used on poultry, representing 4 to 7% of the total antibiotic use in quantitative terms, compared with the 1.6% reported in nine European countries (46).…”